Abstract:
An improved ultrasound-imaging diagnostic system comprises a patient interface configured to measure a patient condition, an ultrasound-imaging system configured to obtain a plurality of medical diagnostic images of a patient treated with a contrast agent over time, a medical diagnostic image manager configured to associate at least one imaging parameter and the patient condition with each of the plurality of medical diagnostic images, and an operator interface configured to receive an operator preference for spatially arranging a plurality of medical diagnostic images. A method for arranging a plurality of diagnostic images comprises collecting a plurality of diagnostic images of a patient, wherein each of the diagnostic images is associated with an image-acquisition mode and a patient condition, receiving a diagnostic directive comprising information responsive to a diagnostician&#39;s preference to observe diagnostic images associated with an image-identifier selected from the group consisting of image-acquisition orientation, image-acquisition mode, and patient condition, identifying a subset of the plurality of diagnostic images responsive to the diagnostic directive, and forwarding the subset of the plurality of diagnostic images to an output device.

Description:
DESCRIPTION OF THE RELATED ART  
         [0001]    The human body is composed of tissues that are generally opaque. In the past, exploratory surgery was one common way to look inside the body. Today, doctors can use a vast array of imaging methods to obtain information about a patient. Some non-invasive imaging techniques include modalities such as X-ray, magnetic resonance imaging (MRI), computer-aided tomography (CAT), ultrasound, and so on. Each of these techniques has advantages that make it useful for observing certain medical conditions and parts of the body. The use of a specific test, or a combination of tests, depends upon the patient&#39;s symptoms and the disease being diagnosed.  
           [0002]    Generally, a trained technician performs a number of tasks to record information required to diagnose one or more medical conditions using a diagnostic imaging system. The technician collects and may even edit portions of the recorded information to identify reference points in the anatomy. Regardless of the underlying image acquisition modality, the images may be recorded on videotape, fixed disk drives, or other data storage devices for later analysis by a physician. For example, images acquired and recorded during an ultrasound exam may be exported to a networked storage device and saved for later evaluation.  
           [0003]    Many clinical diagnostic imaging studies are recorded as a particular test or tests are performed on a patient of interest by a technician. Generally, a trained technician performs a number of tasks in order to record information that is required to diagnose one or more medical conditions using an imaging acquisition system. The technician collects, and may even edit, portions of the recorded information or study to identify reference points in the patient&#39;s anatomy. The images can be recorded on videotape, fixed disk drives, as well as, other data storage devices for later analysis and reporting by a physician.  
           [0004]    Ultrasound-imaging systems can create two-dimensional brightness or B-mode images of tissue in which the brightness of a pixel is based on the intensity of the received ultrasound echoes. In another common imaging modality, typically known as color-flow imaging, the flow of blood or movement of tissue is observed. Color-flow imaging takes advantage of the Doppler effect to color-encode image displays. In color-flow imaging, the frequency shift of backscattered-ultrasound waves is used to measure the velocity of the backscatterers from tissues or blood. The frequency of sound waves reflecting from the inside of blood vessels, heart cavities, etc. is shifted in proportion to the velocity of the blood cells. The frequency of ultrasound waves reflected from cells moving towards the transducer is positively shifted. Conversely, the frequency of ultrasound reflections from cells moving away from the transducer is negatively shifted. The Doppler shift may be displayed using different colors to represent speed and direction of flow. To assist diagnosticians and operators, the color-flow image may be superimposed on the B-mode image.  
           [0005]    Ultrasound imaging can be particularly effective when used in conjunction with contrast agents. In contrast-agent imaging, gas or fluid filled micro-sphere contrast agents known as microbubbles are typically injected into a medium, normally the bloodstream. Due to their physical characteristics, contrast agents stand out in ultrasound examinations and therefore can be used as markers that identify the amount of blood flowing to or through the observed tissue. In particular, the contrast agents resonate in the presence of ultrasound fields producing radial oscillations that can be easily detected and imaged. Normally, this response is imaged at the second harmonic, 2f t  of the fundamental or transmit frequency,f t . By observing anatomical structures after introducing contrast agents, medical personnel can significantly enhance imaging capability for diagnosing the health of blood-filled tissues and blood-flow dynamics within a patient&#39;s circulatory system. For example, contrast agent imaging is especially effective in detecting myocardial boundaries, assessing micro-vascular blood flow, and detecting myocardial perfusion.  
           [0006]    Since the United States Food and Drug Administration (U.S.F.D.A.) approved Left Ventricular Opacification in January of 1998 for human diagnostic imaging, the use of ultrasound contrast agents during stress echocardiographic examinations has seen a steady increase. Imaging techniques are also improving to the point where myocardial opacification may soon become a reality.  
           [0007]    Stress echocardiographic examinations are typically administered by observing a series of ultrasound images recorded while a patient is exercising on a treadmill, stationary bicycle, or other exercise apparatus. Patients that are unable to attain and sustain a desired heart rate via exercise for the duration of the examination may be treated with one or more pharmaceutical agents to elevate their heart rate or as in the case of perfusion, vasodilators to increase blood flow. Because it is undesirable to submit patients to these diagnostic conditions for an extended length of time, there is a desire to keep the acquisition time, and thus the examination times as short as possible. Although contrast agent imaging techniques increase the quality of the diagnostic images, the techniques can add significantly to the length of the examination and the volume of data that needs to be reviewed and analyzed after the data is collected. Consequently, there is a desire to minimize the time required for image acquisition and interpretation.  
           [0008]    Some ultrasound-imaging systems include features, which enable viewing of clinical data along with images acquired during a stress echo examination. For example, the SONOS 5500, commercially available from Koninklijke Philips Electronics N.V., doing business as, Philips Electronics North America Corporation of Tarrytown, N.Y., United States of America, has a feature, which sequences acquired images for tissue motion analysis. The ultrasound images can be displayed in three display modes. A first display mode groups images by a corresponding patient-stress stage (i.e., the images are grouped by stage). The second display mode groups images of the same view (i.e., the images are grouped by subject matter and orientation of the ultrasound transducer). A third display mode displays the images chronologically (i.e., in the sequence in which the images were acquired). A user-selected display mode associates the images into the appropriate group. The operator may then elect to display the grouped images.  
           [0009]    The introduction of contrast agent imaging techniques, which enable physicians and or other diagnosticians to view many different forms of clinical observations in addition to tissue motion has complicated the process of grouping acquired images in a clinically relevant manner. Contrast agent imaging techniques permit the acquisition of data in multiple modes, each of which may provide information on one or more clinical parameters. For example, for a given view at each stage of patient stress, a heart wall motion image can be obtained with or without contrast agent enhanced imaging techniques. Contrast agent imaging techniques also enable the acquisition of real-time perfusion data with loops up to 20 beats or seconds long, triggered perfusion data with a series of frames acquired over the span of 30 seconds to one minute, real-time images with border (i.e., tissue motion) tracking for one or more cardiac cycles, coronary blood-flow data with pulsed wave (PW) Doppler, or 3D images of the cardiac anatomy in addition to many other qualitative and quantitative measurements. Often, the technician will acquire multiple image loops per stress stage and may even acquire multiple loops of the same anatomical view and the same imaging mode at slightly different angles. While the multiple image loops can be acquired and/or stored chronologically throughout the examination, it is very time consuming for a diagnostician to sort through the multiple image loops to determine which images should be analyzed in detail and in what order the acquired images should be reviewed. Often, with contrast agent enhanced imaging loops it is desirable to break up a long loop such as a 20-second loop of real-time tissue perfusion imaging techniques or a one minute acquisition of triggered perfusion images. It is also very time consuming and tedious for the diagnostician to select appropriate portions of these loops for comparison and analysis. With 3D images, it is important for the diagnostician to be able to break a 3D image into a series of 2D images for easier comparison.  
         SUMMARY  
         [0010]    An improved ultrasound-imaging diagnostic display system comprises a patient interface configured to measure a patient condition, an ultrasound-imaging system communicatively coupled to the patient interface configured to obtain a plurality of medical diagnostic images of a patient treated with a contrast agent over time, a medical diagnostic image manager configured to associate at least one imaging parameter and the patient condition with each of the plurality of medical diagnostic images, and an operator interface configured to receive an operator preference for spatially arranging a plurality of medical diagnostic images. Furthermore, the ultrasound-imaging diagnostic display system comprises an interface that enables the user to modify acquired loops by segmenting the loops, combining frames obtained from multiple loops, and displaying the image loops in a manner desired by the diagnostician. The system also comprises an image selector that enables the diagnostic display system to display multiple images acquired from nearly the same perspective of the same anatomical structures, under the same patient condition(s) and same image-acquisition parameters.  
           [0011]    A method for arranging a plurality of diagnostic images, comprises collecting a plurality of diagnostic images of a patient, wherein each of the diagnostic images is associated with an image-acquisition mode and a patient condition, receiving a diagnostic directive comprising information responsive to a diagnostician&#39;s preference to observe diagnostic images associated with an image-identifier selected from the group consisting of image-acquisition orientation, image-acquisition mode, and patient condition, identifying a subset of the plurality of diagnostic images responsive to the diagnostic directive, and forwarding the subset of the plurality of diagnostic images to an output device. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    A system and method for improved diagnostic-image displays are illustrated by way of example and not limited by the embodiments depicted in the following drawings. The components in the drawings are not necessarily to scale. Emphasis instead is placed upon clearly illustrating the principles of the present system and method. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0013]    [0013]FIG. 1 is a schematic diagram illustrating an embodiment of a diagnostic-imaging management system.  
         [0014]    [0014]FIG. 2 is a functional block diagram illustrating an embodiment of the diagnostic image-acquisition system of FIG. 1.  
         [0015]    [0015]FIG. 3A is a plot of a typical adult electrocardiogram that can be produced by the patient condition sensor of FIG. 1.  
         [0016]    [0016]FIG. 3B is a plot of patient-under-test stress over time that can be derived by the diagnostic image acquisition system of FIG. 2.  
         [0017]    [0017]FIG. 4 is a functional block diagram illustrating an embodiment of the workstation of FIG. 1.  
         [0018]    [0018]FIG. 5 is a schematic diagram illustrating an embodiment of a diagnostic image file that can be found in the data store of the image-management system of FIG. 1.  
         [0019]    [0019]FIG. 6 is a functional block diagram illustrating an embodiment of an image manager application that can be stored and executed on the workstation of FIG. 4.  
         [0020]    FIGS.  7 A- 7 D present example embodiments of a diagnostic image display that can be produced on the workstation of FIG. 4.  
         [0021]    [0021]FIG. 8 is a flow chart illustrating a method for improved diagnostic image displays that may be implemented by the diagnostic image-management system of FIG. 1. 
     
    
     DETAILED DESCRIPTION  
       [0022]    The present disclosure generally relates to a system and method for controllably arranging a plurality of diagnostic images. An operator of a diagnostic-image-management system uses an interface to define one or more preferred arrangements for displaying a plurality of diagnostic images on an output device. The operator defines the arrangements by associating a relative output-device position and image size with an image acquired under specific patient conditions and imaging parameters. Thereafter, the diagnostic-image-management system is programmed to identify and render a plurality of diagnostic images in accordance with the operator&#39;s preferences for observing the images.  
         [0023]    An improved diagnostic-image-management system having been summarized above, reference will now be made in detail to the description of the system and method as illustrated in the drawings. For clarity of presentation, the diagnostic-image-management system (DIMS) and an embodiment of the underlying image manager will be exemplified and described with focus on the generation of a composite representation of diagnostic images in formats preferred by a diagnostician operator of the DIMS.  
         [0024]    Turning now to the drawings, wherein like reference numerals designate corresponding parts throughout the drawings, reference is made to FIG. 1, which illustrates a schematic of an embodiment of a DIMS  100 . As illustrated in the schematic of FIG. 1, DIMS  100  includes a diagnostic image-acquisition system  110  as well as an image-management system  120 . Image-management system  120  includes workstation  130  and data store  140 . Workstation  130  is communicatively coupled with data store  140  via interface  132 .  
         [0025]    Diagnostic image-acquisition system  110  and image-management system  120  are communicatively coupled to each other via interface  112  to enable an operator of workstation  130  to access, arrange, and display diagnostic images accumulated during one or more patient examinations. Diagnostic image-acquisition system  110  is coupled to patient condition sensor  115  and patient imaging sensor  117  via interface  114  and interface  116 , respectively. Patient condition sensor  115  is configured to monitor one or more patient parameters or conditions, such as heart rate, respiratory rate, blood oxygen saturation, temperature, etc. Interface  114  is configured to communicatively couple one or more time varying signals from one or more transducers included within patient condition sensor  115  to the diagnostic image-acquisition system  110 .  
         [0026]    As will be explained below, a diagnostic image can be acquired by the diagnostic image acquisition system  110 , or otherwise received by, the general-purpose computer  131  operating within the DIMS  100 . For example, a diagnostic image can be acquired from an ultrasound imaging system, a computer-aided tomography (CAT) imaging system, a magnetic resonance imaging (MRI) system, among others.  
         [0027]    Because the examples presented below describe heart studies of a patient-under-test  150  that include the acquisition, identification, and arrangement of ultrasound echo induced diagnostic images, subsequent references to patient condition sensor  115  are limited to transducers used in association with an electrocardiographic processor to produce a signal representative of heart muscle activity over time. However, patient-condition sensor  115  as used in the present system and method for improved diagnostic image displays is not limited to electrocardiographic transducers.  
         [0028]    Patient imaging sensor  117  is configured to provide a plurality of signals via interface  116  to the diagnostic image-acquisition system  110 . The plurality of signals are in turn received, buffered, and processed in accordance with known techniques in order to produce one or more graphic representations of various portions of the anatomy of the patient-under-test  150 . In preferred embodiments, patient-imaging sensor  117  is an ultrasound transducer. In alternative embodiments, patient-imaging sensor  117  can include a magnetic resonance imaging sensor, an x-ray sensor, etc.  
         [0029]    Workstation  130  includes a general-purpose computer  131 . The general-purpose computer  131  is communicatively coupled to both data store  140  and diagnostic image-acquisition system  110  via interface  132  and interface  112 , respectively. Interfaces  112 ,  132  can be wired interfaces, wireless (e.g., a radio-frequency) interfaces, and/or networks that couple workstation  130  to one or more diagnostic image-acquisition systems  110  and one or more distributed data storage devices included in data store  140 . Alternatively, the image management system  120  can reside in the diagnostic image acquisition system  110 .  
         [0030]    Interfaces  112 ,  132  can be interfaces commonly available with general-purpose computers such as a serial, parallel, universal serial bus (USB), USB II, the institute of electrical and electronics engineers (IEEE) 1394 interface, also known as “Firewire®,” or the like. Firewire is the registered trademark of Apple Computer, Inc. of Cupertino, Calif., U.S.A. Furthermore, interfaces  112 ,  132  may use different standards or proprietary communications protocols for different types of image sources.  
         [0031]    When interfaces  112 ,  132  are implemented via a network, the interfaces  112 ,  132  can be any local area network (LAN) or wide area network (WAN). When configured as a LAN, the LAN can be configured as a ring network, a bus network, and/or a wireless-local network. When the interfaces  112 ,  132  are implemented over a WAN, the WAN could be the public-switched telephone network, a proprietary network, and/or the public access WAN commonly known as the Internet.  
         [0032]    Regardless of the actual network infrastructure used in particular embodiments, diagnostic-image data can be exchanged with general-purpose computer  131  of workstation  130  using various communication protocols. For example, transmission-control protocol/Internet protocol (TCP/IP) may be used if the interfaces  112 ,  132  are configured over a LAN or a WAN. Proprietary data-communication protocols may also be used when the interfaces  112 ,  132  are configured over a proprietary LAN or WAN.  
         [0033]    Regardless of the underlying patient imaging technology used by the diagnostic image-acquisition system  110 , images of the anatomy of the patient-under-test  150  are captured or otherwise acquired by an image-recording subsystem within the diagnostic image-acquisition system  110 . Acquired images include information defining the characteristics observed for each of a plurality of picture elements or pixels that define the diagnostic image. Each pixel includes digital (i.e., numeric) information describing the colors and intensity of light observed at a particular region of an image sensor. The digital information arranged in a two-dimensional array of pixels can be used by suitably configured devices (e.g., the general-purpose computer  131 , a photo-quality printer (not shown), etc.) to create a rendition of the captured image.  
         [0034]    Because various types of image-processing devices can be easily coupled to the DIMS  100  (e.g., a video-tape recorder/player, a digital-video disk (DVD) recorder/player, etc.), previously recorded images stored on various media (e.g., a computer diskette, a flash-memory device, a compact-disk (CD), a magnetic tape, etc.) can be transferred to workstation  130  and/or data store  140  for processing in accordance with an image manager application program operable on the general-purpose computer  131  of the workstation  130 . After processing by the image-management system  120  in accordance with preferred methods for arranging and displaying a plurality of the acquired and/or previously stored diagnostic images, the DIMS  100  can store the various composite image arrangements on a suitable data-storage medium.  
         [0035]    Those skilled in the art will understand that a plurality of images from one or more patient studies can be presented in sequence. Such sequences or image loops can be repeated (i.e., the general-purpose computer  131  can present the first image and each subsequent image in the sequence after the last image in the sequence has been presented) as may be desired by a diagnostician or other operator of the image-management system  120 .  
         [0036]    Any combination of image-acquisition devices and/or data-storage devices may be included in DIMS  100 . In addition, DIMS  100  may contain more than one image source of the same type. DIMS  100  may further include devices to which a digital image captured or otherwise acquired from a diagnostic image-acquisition system or a data-storage device can be sent. Such devices include hard-copy output devices such as a photo-quality printer.  
         [0037]    Those skilled in the art will understand that various portions of DIMS  100  can be implemented in hardware, software, firmware, or combinations thereof. In a preferred embodiment, DIMS  100  is implemented using a combination of hardware and software or firmware that is stored in memory and executed by a suitable instruction-execution system. If implemented solely in hardware, as in an alternative embodiment, DIMS  100  can be implemented with any or a combination of technologies which are well-known in the art (e.g., discrete-logic circuits, application-specific integrated circuits (ASICs), programmable-gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.), or later developed technologies. In a preferred embodiment, the functions of the DIMS  100  are implemented in a combination of software and data executed and stored under the control of the general-purpose computer  131 . It should be noted, however, that the DIMS  100  is not dependent upon the nature of the underlying computer in order to accomplish designated functions.  
         [0038]    Reference is now directed to FIG. 2, which illustrates a functional block diagram of ant embodiment of the diagnostic image-acquisition system  110  of FIG. I. In this regard, the diagnostic image-acquisition system  110  may include ultrasound-imaging electronics  200  common to many ultrasound-imaging systems. As shown in FIG. 2, ultrasound-imaging electronics  200  are in communication with electrocardiographic transducer(s)  215 , an ultrasound transducer  217 , and a display electronics system  250 . Ultrasound-imaging electronics  200  includes a system controller  212  that controls the operation and timing of the various functional elements and signal flows within the diagnostic image-acquisition system  110  pursuant to suitable software.  
         [0039]    System controller  212  is coupled to transmit controller  214  which produces a plurality of various ultrasound signals that are controllably forwarded to the ultrasound transducer  217  via radio-frequency (RF) switch  216 . Ultrasound echoes received from portions of the anatomy of the patient-under-test  150  (FIG. 1) are converted to electrical signals in ultrasound transducer  217  and forwarded via RF switch  216  to a receive channel that includes analog to digital converters  218 , beamformer  224 , digital filter  226 , and various image processors  228 .  
         [0040]    Ultrasound transducer  217  is configured to emit and receive ultrasound signals, or acoustic energy, to and from an object-under-test (e.g., the anatomy of the patient-under-test) when the ultrasound-imaging electronics  200  are used in the context of a medical application). The ultrasound transducer  217  is preferably a phased-array transducer having a plurality of elements both in the azimuth and elevation directions.  
         [0041]    In one embodiment, the ultrasound transducer  217  comprises an array of elements typically made of a piezoelectric material, for example but not limited to, lead-zirconate-titanate (PZT). Each element is supplied an electrical pulse or other suitable electrical waveform, causing the elements to collectively propagate an ultrasound-pressure wave into the object-under-test. Moreover, in response thereto, one or more echoes are reflected by various tissues within the patient and are received by the ultrasound transducer  217 , which transforms the echoes into a plurality of electrical signals.  
         [0042]    The array of elements associated with the ultrasound transducer  217  enable a beam, emanating from the transducer array, to be steered (during transmit and receive modes) through the patient-under-test by shifting the phase (introducing a time delay) of the electrical pulses (i.e., the transmit signals) supplied to the separate transducer elements. During a transmit mode, an analog waveform is communicated to each transducer element, thereby causing a pulse to be selectively propagated in a particular direction, like a beam, through the patient.  
         [0043]    During a receive mode, an analog waveform is received at each transducer element at each transducer element. Each analog waveform essentially represents a succession of echoes received by the ultrasound transducer  217  over a period-of-time as echoes are received along the single beam through the patient. The entire set of analog waveforms represents an acoustic line, and the entire set of acoustic lines represents a single view, or image, of an object and is commonly referred to as a frame. Each frame represents a separate diagnostic image that can be stored within the image-management system  120  for later arrangement in a preferred diagnostic routine. Note that frame (i.e., image data storage) can be implemented on a frame by frame or a multiple frame basis.  
         [0044]    In addition to forwarding the acquired digital images to image-management system  120 , diagnostic image-acquisition system  10  can forward each image to display electronics systems  250 . Display electronics system  250  includes video processor  252 , video memory  254 , and monitor  256 . As shown in FIG. 2, monitor  256  may be configured to receive a video-input signal from video memory  254  and/or video processor  252 . This multiple video signal input arrangement enables both real-time image observations, as well as post-test diagnostic viewing of stored diagnostic images. In order to enable post-test diagnostic viewing, video memory  254  can include a digital-video disk (DVD) player/recorder, a compact-disc (CD) player/recorder, a video-cassette recorder (VCR) or other various video-information storage devices.  
         [0045]    Those skilled in the art will understand that display-electronics system  250  may be integrated and/or otherwise co-located with the diagnostic image-acquisition system  110 . Alternatively, the display-electronics system  250  can be integrated and/or otherwise co-located with workstation  130 . In other embodiments, separate display-electronics systems  250  can be integrated with workstation  130  and diagnostic image-acquisition system  110 .  
         [0046]    In operation, system controller  212  can be programmed or otherwise configured to forward one or more control signals to direct operation of the transmit, controller  214 . Generally, a test technician will configure the ultrasound-imaging electronics  200  to coordinate the application of appropriate ultrasound signal transmissions, as well as to coordinate the selective observation of the resulting ultrasound echoes to record a plurality of image loops. Note that system controller  212  may forward various control signals in response to one or more signals received from electrocardiographic transducers  215  and/or other patient condition sensors (not shown). In response, transmit controller  214  generates a series of electrical pulses that are periodically communicated to a portion of the array of elements of the ultrasound transducer  217  via RF switch  216 , causing the transducer elements to emit ultrasound signals into the object-under-test of the nature described previously. The transmit controller  214  typically provides separation (in time) between the pulsed transmissions to enable the ultrasound transducer  217  to receive echoes from patient-under-test tissues during the period between pulsed transmissions. RF switch  216  forwards the received echoes via the ADCs  218  to a set of parallel channels within the beamformer  224 .  
         [0047]    When the transmit pulses (in the form of ultrasound energy) encounter a tissue layer of the patient-under-test  150  that is receptive to ultrasound insonification, the multiple transmit pulses penetrate the tissue layer. As long as the magnitude of the multiple ultrasound pulses exceeds the attenuation affects of the tissue layer, the multiple ultrasound pulses will reach an internal target. Those skilled in the art will appreciate that tissue boundaries or intersections between tissues with different ultrasound impedances will develop ultrasound responses at the fundamental or transmit frequency,f 1 , of the plurality of ultrasound pulses. Tissue insonified with ultrasound pulses will develop fundamental-ultrasound responses that may be distinguished in time from the transmit pulses to convey information from the various tissue boundaries within a patient.  
         [0048]    Those ultrasound reflections of a magnitude that exceed that of the attenuation affects from traversing tissue layer may be monitored and converted into an electrical representation of the received ultrasound echoes. Those skilled in the art will appreciate that those tissue boundaries or intersections between tissues with different ultrasound impedances will develop ultrasound responses at both the fundamental frequency, f t , as well as, at harmonics (e.g., 2f t , 3f t , 4f t , etc.) of the fundamental frequency of the plurality of ultrasound pulses. Tissue insonified with ultrasound pulses will develop both fundamental and harmonic-ultrasound responses that may be distinguished in time from the transmit pulses to convey information from the various tissue boundaries within a patient. It will be further appreciated that tissue insonified with ultrasound pulses develops harmonic responses because the compressional portion of the insonified waveforms travels faster than the rarefactional portions. The different rates of travel of the compressional and the rarefactional portions of the waveform causes the wave to distort producing a harmonic signal, which is reflected or scattered back through the various tissue boundaries.  
         [0049]    Preferably, ultrasound-imaging electronics  200  transmit a plurality of ultrasound pulses via ultrasound transducer  217  at a fundamental frequency and receive a plurality of ultrasound-echo pulses or receive pulses at an integer harmonic of the fundamental frequency. Those skilled in the art will appreciate that harmonic responses may be received by the same transducer when the ultrasound transducer  217  has an appropriately wide frequency band width.  
         [0050]    While the internal target within the patient-under-test  150  will produce harmonic responses at integer multiples of the fundamental frequency, various contrast agents have been shown to produce subharmonic, harmonic, and ultraharmonic responses to incident ultrasound pulses. Consequently, observation of ultrasound echoes when the patient-under-test  150  has been treated (i.e., injected) with one or more contrast agents has proven beneficial to monitoring cardiac chambers, valves, and blood supply dynamics. Those ultrasound reflections of a magnitude that exceed that of the attenuation affects from traversing the various tissues of the patient-under-test  150  are converted into a plurality of electrical signal by the ultrasound transducer  217 .  
         [0051]    Beamformer  224  receives the echoes as a series of waveforms converted by ADCs  218 . More specifically, beamformer  224  receives a digital version of an analog waveform from a corresponding transducer element for each acoustic line. Moreover, beamformer  224  receives a series of waveform sets, one set for each separate acoustic line, in succession over time and processes the waveforms in a pipeline-processing manner. Because the ultrasound signals received by ultrasound transducer  217  are of low power, a set of preamplifiers (not shown) may be disposed within beamformer  224 .  
         [0052]    In this way, beamformer  224  receives a series of waveforms corresponding to separate acoustic lines in succession over time and processes the data in a pipeline-processing manner. Beamformer  224  combines the series of received waveforms to form a single acoustic line. To accomplish this task, beamformer  224  may delay the separate echo waveforms by different amounts of time and then may add the delayed waveforms together, to create a composite digital RF acoustic line. The foregoing delay and sum beamforming process is well known in the art. Furthermore, beamformer  224  may receive a series of data collections for separate acoustic lines in succession over time and process the data in a pipeline-processing manner.  
         [0053]    Because the echo waveforms typically decay in amplitude as they are received from progressively deeper depths in the patient, beamformer  224  may further comprise a parallel plurality of time-gain compensators (TGCs—not shown), which are designed to progressively increase the gain along the length of each acoustic line, thereby reducing the dynamic range requirements on subsequent processing stages. Moreover, the set of TGCs may receive a series of waveform sets, one set for each separate acoustic line, in succession over time and may process the waveforms in a pipeline-processing manner.  
         [0054]    Each of the waveforms processed by beamformer  224  may be forwarded to digital filter  226 . The waveforms include a number of discrete-location points (hundreds to thousands; corresponding with depth and ultrasound-transmit frequency) with respective quantized instantaneous signal levels, as is well known in the art. In previous ultrasound-imaging systems, this conversion often occurred later in the signal-processing stages, but recently, many of the logical functions that are performed on the ultrasonic signals can be digital, and hence, the conversion is preferred at an early stage in the signal-processing process.  
         [0055]    Digital filter  226  can be configured as a frequency band pass filter configured to remove undesired high-frequency out-of-band noise from the plurality of waveforms. The output of the digital filter  226  can then be coupled to an I, Q demodulator (not shown) configured to receive and process digital-acoustic lines in succession. The I, Q demodulator may comprise a local oscillator that may be configured to mix the received digital-acoustic lines with a complex signal having an in-phase (real) signal and a quadrature-phase (imaginary) signal that are ninety degrees out-of-phase from one another. The mixing operation may produce sum and difference-frequency signals. The sum-frequency signal may be filtered (removed), leaving the difference-frequency signal, which is a complex signal centered near zero frequency. This complex signal is desired to follow direction of movement of anatomical structures imaged in the object-under-test, and to allow accurate, wide-bandwidth amplitude detection.  
         [0056]    Up to this point in the ultrasound echo-receive process, all operations can be considered substantially linear, so that the order of operations may be rearranged while maintaining substantially equivalent function. For example, in some systems it may be desirable to mix to a lower intermediate frequency or to baseband before beamforming or filtering. Such rearrangements of substantially linear processing functions are considered to be within the skill set of those skilled in the art of ultrasound-imaging systems.  
         [0057]    A plurality of signal processors  228  are coupled to the output of the digital filter  226  via I, Q demodulator. For example, a B-mode processor, a Doppler processor, and/or a color-flow processor, among others may be introduced at the output of the I, Q demodulator. Each of the image processors  228  includes a suitable species of random-access memory (RAM) and is configured to receive the filtered digital-acoustic lines. The acoustic lines can be defined within a two-dimensional coordinate space and may contain additional information that can be used in generating a three-dimensional image. Furthermore, the various image processors  228  accumulate acoustic lines of data over time for signal manipulation.  
         [0058]    Regardless of the location of the display-electronics system  250 , video processor  252  may be configured to produce two-dimensional and three-dimensional images from the data in the RAM once an entire data frame (i.e., a set of all acoustic lines in a single view or image to be displayed) has been accumulated by the RAM. For example, if the received data is stored in RAM using polar coordinates to define the relative location of the echo information, the video processor  252  may convert the polar coordinate data into rectangular (orthogonal) data capable of raster scan via a raster-scan capable display monitor  256 .  
         [0059]    When patient-condition sensor  115  (FIG. 1) includes a plurality of electrocardiographic transducers  215  placed on the patient-under-test&#39;s chest, the plurality of transducers generate a set of electrical signals that represent chest movement over time. FIG. 3A illustrates a plot  300  of a typical adult&#39;s heart muscle activity (as observed through chest movement) over time as may be recorded by a suitably configured electrocardiographic-measurement subsystem within the diagnostic image-acquisition system  110  of FIG. 1. Because human heart motion is periodic, characteristic portions of the plot  300  can be used to trigger or otherwise coordinate the application of one or more transmit control signals via RF switch  216  to the ultrasound transducer  216  (FIG. 2). When the diagnostic image-acquisition system  110  is an ultrasound imaging system, ultrasound energy echoes received in the ultrasound transducer  217  as a result of transmitted ultrasound energy can be used to produce images that capture the heart muscle during specific events within the heart cycle. For example, one skilled in the art could use the plot  300  to coordinate the acquisition of an ultrasound image of the patient&#39;s heart that corresponds to the systole and diastole of the left ventricle. By coordinating the acquisition of multiple images of a patient&#39;s heart at a similar point in the heart cycle under multiple image-acquisition modes, viewing orientations, and patient conditions, a diagnostician can increase their understanding of the patient&#39;s condition.  
         [0060]    [0060]FIG. 3B illustrates one way to quantify a patient&#39;s condition during a stress test. Stress tests are generally performed to give a diagnostician information regarding what is happening within a patient-under-test&#39;s heart when the patient&#39;s heart rate or blood flow increases. One way to quantify patient stress is to plot a patient&#39;s heart rate over time.  
         [0061]    As illustrated in FIG. 3B, patient stress can be quantified in relation with a particular patient&#39;s heart rate at rest. Multiple stress stages can then be identified by applying a function to the patient&#39;s heart rate at rest. In the example of FIG. 3B, the patient achieves a stage I stress level when his heart rate increases by A, a predetermined percentage, above the patient&#39;s heart rate at rest. Stage II through stage IV stress levels are attained when the patient&#39;s heart rate exceeds the patient&#39;s heart rate at rest by larger percentages. As is further shown in FIG. 3B, the patient associated with patient stress plot  350  is characterized as attaining a stage I stress level during time periods t 1  to t 2  and t 7  to t 8 . The patient attained stress level II during time periods t 2  to t 3  and t 6  to t 7 . The patient attained stress level II during time periods t 3  to t 4  and t 5  to t 6 . The patient attained the highest stress level, stress level IV, during time period t 4  to t 5 . As will be further explained below, patient stress stage or stress level can be used as one of many patient conditions or patient parameters to enable a diagnostician of heart function to categorize, identify, and arrange a plurality of diagnostic images.  
         [0062]    Reference is now directed to FIG. 4, which illustrates a functional block diagram of the general-purpose computer  131  of FIG. 1. Generally, in terms of hardware architecture, as shown in FIG. 4, the general-purpose computer  131  may include a processor  400 , memory  402 , input device(s)  410 , output device(s)  412 , and network interface(s)  414 , that are communicatively coupled via local interface  408 .  
         [0063]    Local interface  408  can be, for example but not limited to, one or more buses or other wired or wireless connections, as is known in the art or may be later developed. Local interface  408  may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers, to enable communications. Further, local interface  408  may include address, control, and/or data connections to enable appropriate communications among the aforementioned components of the general-purpose computer  131 .  
         [0064]    In the embodiment of FIG. 4, the processor  400  is a hardware device for executing software that can be stored in memory  402 . The processor  400  can be any custom-made or commercially-available processor, a central-processing unit (CPU) or an auxiliary processor among several processors associated with the general-purpose computer  131  and a semiconductor-based microprocessor (in the form of a microchip) or a macroprocessor.  
         [0065]    The memory  402  can include any one or combination of volatile memory elements (e.g., random-access memory (RAM, such as dynamic-RAM or DRAM, static-RAM or SRAM, etc.)) and nonvolatile-memory elements (e.g., read-only memory (ROM), hard drives, tape drives, compact-disk drives (CD-ROMs), etc.). Moreover, the memory  402  may incorporate electronic, magnetic, optical, and/or other types of storage media now known or later developed. Note that the memory  402  can have a distributed architecture, where various components are situated remote from one another, but accessible by processor  400 .  
         [0066]    The software in memory  402  may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. In the example of FIG. 4, the software in the memory  402  includes image manager  416  that functions as a result of and in accordance with operating system  406 . Memory  402  also includes image files  510  that contain information used to produce one or more representations of diagnostic images acquired by the diagnostic image-acquisition system  110  of FIG. 1. Operating system  406  preferably controls the execution of computer programs, such as image manager  416 , and provides scheduling, input-output control, file and data management, memory management, and communication control and related services.  
         [0067]    In an embodiment, image manager  416  is one or more source programs, executable programs (object code), scripts, or other collections each comprising a set of instructions to be performed. It will be well understood by one skilled in the art, after having become familiar with the teachings of the system and method, that image manager  416  may be written in a number of programming languages now known or later developed.  
         [0068]    The input device(s)  410  may include, but are not limited to, a keyboard, a mouse, or other interactive-pointing devices, voice-activated interfaces, or other operator-machine interfaces (omitted for simplicity of illustration) now known or later developed. The input device(s)  410  can also take the form of an image-acquisition device or a data-file transfer device (e.g., a floppy-disk drive, a digital-video disk (DVD) player, etc.). Each of the various input device(s)  410  may be in communication with the processor  400  and/or the memory  402  via the local interface  408 . Data received from an image-acquisition device connected as an input device  410  or via the network interface device(s)  414  may take the form of a plurality of pixels, or a data file such as image file  510 .  
         [0069]    The output device(s)  412  may include a video interface that supplies a video-output signal to a display monitor associated with the respective general-purpose computer  131 . Display devices that can be associated with the general-purpose computer  131  are conventional CRT based displays, liquid-crystal displays (LCDs), plasma displays, image projectors, or other display types now known or later developed. It should be understood, that various output device(s)  412  may also be integrated via local interface  408  and/or via network-interface device(s)  414  to other well-known devices such as plotters, printers, copiers, etc.  
         [0070]    Local interface  408  may also be in communication with input/output devices that communicatively couple the general-purpose computer  131  to a network. These two-way communication devices include, but are not limited to, modulators/demodulators (modems), network-interface cards (NICs), radio frequency (RF) or other transceivers, telephonic interfaces, bridges, and routers. For simplicity of illustration, such two-way communication devices are represented by network interface(s)  414 .  
         [0071]    Local interface  408  is also in communication with time-code generator  430 . Time-code generator  430  provides a time-varying signal to the image manager  416 . The time-varying signal can be generated from an internal clock within the general-purpose computer  131 . Alternatively, the time-code generator  430  may be in synchronization with an externally generated timing signal. Regardless of its source, time-code generator  430  forwards the time-varying signal that is received and applied by image manager  416  each time an image is acquired by the image-management system  120  for the first time.  
         [0072]    When the general-purpose computer  131  is in operation, the processor  400  is configured to execute software stored within the memory  402 , to communicate data to and from the memory  402 , and to generally control operations of the general-purpose computer  131  pursuant to the software. The image manager  416  and the operating system  406 , in whole or in part, but typically the latter, are read by the processor  400 , perhaps buffered within the processor  400 , and then executed.  
         [0073]    The image manager  416  can be embodied in any computer-readable medium for use by or in connection with an instruction-execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction-execution system, apparatus, or device, and execute the instructions. In the context of this disclosure, a “computer-readable medium” can be any means that can store, communicate, propagate, or transport a program for use by or in connection with the instruction-execution system, apparatus, or device. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium now known or later developed. Note that the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.  
         [0074]    [0074]FIG. 5 presents an example of an internal data structure  520  that can be applied to one or more image files  510 . As illustrated, each of the image files  510  includes an image file header  522  and image information  524 . As illustrated in the table shown below the data structure  520 , the image file header  522  includes a plurality of bits with bits  0  through V designated to store a study identifier, bits V+1 through W designated to store a diagnostic test identifier, bits W+1 through X designated to store an image-acquisition mode, bits X+1 through Y designated to store an image-acquisition orientation, and bits Y+1 through Z designated to store a patient condition.  
         [0075]    Those skilled in the art should understand that the example image-file header  522  may be arranged in various ways, which include but are not limited to rearranging the order and relative length in bits of each of the image-file header parameters, adding image parameters including operational parameters associated with the underlying image-acquisition system, adding patient conditions, etc.  
         [0076]    In an alternative embodiment (not illustrated), the first of a sequence of images may include an image-file header  522  that includes an image loop-length parameter. The image loop-length parameter identifying a number of images and/or their individual locations in memory  402  to enable a plurality of the diagnostic images to be concatenated together to permit time motion analysis of the patient&#39;s heart.  
         [0077]    Note that the diagnostic image-acquisition system  110  can be triggered as explained above to capture diagnostic images in real-time for motion studies of the various structures of the patient-under-test&#39;s heart. Alternatively, the diagnostic image-acquisition system  110  can be triggered by various characteristics of the patient&#39;s electrocardiographic results to acquire diagnostic images at particular portions of the patient-under-test&#39;s heart cycle.  
         [0078]    Reference is now directed to FIG. 6, which presents an embodiment of a functional block diagram of the image manager  416  of FIG. 4. As illustrated in FIG. 6, image manager  416  comprises an operator interface  610  and an image categorizer  620 . Operator interface  610  is in communication with one or more input device(s)  410 , the image categorizer  620 , and one or more output device(s)  412 . Image categorizer  620  includes a file-header editor  622 , operator preferences  624 , and an image selector  626 .  
         [0079]    In a first mode of operation, image manager  416  receives information indicative of an operator&#39;s preferences for observing a plurality of diagnostic images in an arrangement that provides a composite view. In this regard, operator interface  610  is configured to present an operator preferences display  625  that is arranged to provide both a summary of presently selected display preferences for viewing images of the type typically provided by a presently active diagnostic test type and a plurality of options for modifying a diagnostic image display  700 . The operator preferences display  625  may also include an indication of a default display arrangement for the presently active diagnostic test type.  
         [0080]    An operator of the image-management system  120  uses the operator interface  610  to configure one or more operator preferences  624  for each diagnostic test type that can be performed by the diagnostic image-acquisition system  110 . Operator preferences  624  include information that describes the relative position and size of each of a plurality of diagnostic images identified by a combination of imaging parameters and patient conditions in addition to the diagnostic test type. Operator preferences  624  can also include information that describes various clinical data, which a diagnostician may prefer to observe when analyzing the various images.  
         [0081]    In an image acquisition and storage mode, image categorizer  620  receives and processes each diagnostic image the first time the image is processed by the image-management system  120 . As illustrated in FIG. 6, the file-header editor  622  receives image parameters  603  and patient conditions  605  and associates the various parameters and conditions as observed at the time each diagnostic image was acquired by the diagnostic image-acquisition system  110  to the various image files  510  as described above with regard to file structure  520 . File-header editor  622  modifies the respective image files  510  and returns the updated image files  510  to data store  140  (FIG. 1) or an internal data-storage device associated with general-purpose computer  131  of workstation  130 . Note that in some embodiments the data store  140  can be arranged to facilitate image data access. Various arrangements may include storing related images in folders.  
         [0082]    In an image display mode, image categorizer  620  applies operator preferences  624  over a plurality of previously acquired and modified diagnostic images  510  to identify which of the plurality of images meet the preferred criteria as selected by an operating diagnostician of the image-management system  120 . As illustrated in FIG. 6, image files  510  are filtered or otherwise identified by the image selector  626  in accordance with the operator specified preferences for arranging the diagnostic images. For example, a diagnostician may be interested in observing different anatomical views of a cardiac patient&#39;s heart (e.g., apical-4, apical-2, parasternal long, parasternal short, etc.) over four stages of stress. The stages of stress can be applied as described above. Alternatively, the stages of stress can be identified by dosage levels of one or more stimulants introduced into the patient-under-test&#39;s bloodstream to increase the patient&#39;s heart rate or blood flow.  
         [0083]    In one display arrangement, the diagnostician may prefer to see the apical-4-stage IV image loop on the right side of the diagnostic-image display  700  and the apical 4-stage III image loop on the left side of the diagnostic-image display  700 . The diagnostician may specifically request that the technician observe and record the stimulant and dosage levels, the patient s heart and respiratory rates, as well as other types of clinical information and/or image acquisition parameters during the examination. The diagnostician may then add the clinical information and image-acquisition parameters over a designated portion of the diagnostic-image display  700 .  
         [0084]    Image selector  626  uses timing information inserted by file header editor  622  into each of the plurality of image files  510  to synchronize the various diagnostic images that are arranged on a particular diagnostic display  700 . As described above, the relative timing information may be provided by the time code generator  430  (FIG. 4) and/or the electrocardiographic transducers  215  (FIG. 2).  
         [0085]    Alternatively, image selector  626  can be programmed to extract relative timing information from diagnostic images acquired and stored with other diagnostic imaging systems. It should be understood that various timestamps or other indication of the image acquisition time can be encoded and inserted into the image-file header  522  as described above, a separate image-management database, or may be encoded within the image information  524 . In still another alternative, image selector  626  includes logic that identifies closely related image subject matter, that is, diagnostic images of structures acquired from slightly different acquisition angles.  
         [0086]    [0086]FIG. 7A illustrates an embodiment of a diagnostic image viewer  710  that can be programmed to present a plurality of diagnostic images in accordance with the observation preferences of a diagnostician of the image-management system  120 . As shown in FIG. 7A, diagnostic-image viewer  710  is a graphical-user interface (GUI) that includes a pull-down menu bar  712  and a plurality of iconic task pushbuttons. The GUI includes a left-side diagnostic-image panel  720  and a right-side diagnostic-image panel  730 . The left-side diagnostic-image panel  720  includes a diagnostic image of tissue(s) of interest  722  (e.g., a portion of a patient&#39;s cardiac blood supply vessels), patient conditions  724 , as well as imaging parameters  726 . Similarly, the right-side diagnostic-image panel  730  includes a diagnostic image of tissue(s) of interest  732  acquired after the diagnostic image presented in the left-side diagnostic-image panel  720  as can be seen by the perfusion of contrast agent in the blood supply entering the cardiac vessel from the right. Right-side diagnostic-image panel  730  also includes patient conditions  734  and imaging parameters  736  as observed when the diagnostic image of the tissue(s) of interest  732  was acquired.  
         [0087]    Diagnostic-image viewer  710  also includes a plurality of functional pushbuttons labeled step, “loop,” “clear,” “print,” “view,” and “stop.” Step pushbutton  749  is associated with logic that displays successive diagnostic images one at a time within both the right and left-side diagnostic-image panels  730 ,  720 , respectively, in the sequence that they were acquired during the stress examination. Loop pushbutton  751  is associated with logic that displays successive diagnostic images within both the right and left-side diagnostic-image panels  730 ,  720 , respectively, in real-time or as triggered by various portions of the heart cycle in the sequence that they were acquired during the stress examination. Image loops are desired to observe contrast agent perfusion of the tissues of interest, which may take several cardiac cycles. Clear pushbutton  753  is associated with logic that removes the diagnostic images of the tissue(s) of interest  722 ,  732 , patient conditions  724 ,  734 , and imaging parameters  726 ,  736  from the diagnostic image viewer  710 . Print pushbutton  755  is associated with logic that forwards the present condition of the diagnostic image viewer  710  to a hard-copy device of choice. View pushbutton  757  is associated with logic that enables a diagnostician to enlarge a select portion of the diagnostic images of the tissue(s) of interest  722 ,  732 . Preferably, when the diagnostician indicates that a particular portion of one of the two diagnostic images of the tissue(s) of interest  722 ,  732  should be enlarged, the other diagnostic image of interest responds accordingly. Stop pushbutton  759  is associated with logic that prevents the diagnostic image viewer  710  from progressing to a subsequent set of images while in the loop display mode.  
         [0088]    The diagnostic image viewer  710  includes additional control interfaces that enable a diagnostician to modify various preferred arrangements of the diagnostic images. The additional control interfaces include end-systolic pushbutton  761 , end-diastolic pushbutton  763 , other pushbutton  765 , segment pushbutton  767 , compare pushbutton  769 , and select pushbutton  771 .  
         [0089]    End-systolic pushbutton  761  is associated with logic that identifies and displays diagnostic images acquired in synchronization with the termination of the systolic portion of the patient&#39;s heart cycle. End-diastolic pushbutton  763  is associated with logic that identifies and displays diagnostic images acquired in synchronization with the termination of the diastolic portion of the patient&#39;s heart cycle. Other pushbutton  765  is associated with logic that displays a menu that provides a mechanism for a diagnostician to select only images acquired at some other portion of the patient&#39;s heart cycle for display.  
         [0090]    Segment pushbutton  767  is associated with logic that enables a diagnostician to divide an image loop into multiple image loops each having the same period. For example, in a default mode, the image manager  416  may be programmed to identify an image loop segment acquired during the first cardiac cycle after one or more contrast agent destructive ultrasound energy pulse(s) and identify and display other real-time image loops acquired over the same cardiac cycle. Similarly, an image loop acquired during the n th  cardiac cycle after the contrast agent destructive ultrasound energy pulse(s) can be arranged for display with real-time image loops acquired over the n th  cardiac cycle.  
         [0091]    Compare pushbutton  769  is associated with logic that enables a diagnostician to select and display a specific cardiac cycle after the contrast agent destructive ultrasound energy pulses acquired with the patient at rest to a specific cardiac cycle acquired during a designated level of stress. Note that the cardiac cycles are not necessarily synchronized. Compare pushbutton  769  is preferrably programmed with a set of default values. In addition, compare pushbutton  769  initiates a menu or other secondary interface (e.g., a popup interface) to permit a diagnostician to controllably select multiple options when comparing segmented image loops. Diagnostic image viewer  710  includes a secondary interface (not shown) such as a pushbutton that enables a diagnostician to quickly select each preferred diagnostic imaging display.  
         [0092]    The additional control interfaces may be used when observing real-time myocardial opacification in image loops. When comparing diagnostic images acquired in real-time, image manager  416  may be controllably adjusted to display image loops with tissue perfusion at slower rates to enable a diagnostician to observe blood flow through various tissues of interest.  
         [0093]    With controllably triggered images, it is often desired to observe multiple images of the heart at the same portion of the cardiac cycle (e.g., end systole) with images from approximately the same trigger interval provided within the diagnostic image viewer  710 . Image manager  416  is programmed with the flexibility to permit a diagnostician to compare different parts of one loop to different parts of the same loop or another loop acquired at a certain patient condition or anatomical view. For example, comparing the triggered or real-time perfusion images from a particular view every 4 th  cardiac cycle at rest to every cardiac cycle during peak stress has shown to be extremely useful. The DIMS  100  enables the diagnostician to arrange these multiple image loops for comparison and observation automatically once the diagnostician has entered and stored the diagnostician&#39;s display preferences.  
         [0094]    In some imaging modes, contrast agent destruction can occur with every image or frame. Consequently, image loops in these imaging modes often comprise a sequence of images where the delay between acquiring each subsequent image changes within the loop. For example, diagnostic image loops can consist of a sequence that triggers (i.e., acquires an image) every n th  cardiac cycle for each frame, where n can progressively increase. A typical sequence may look something like 1, 1, 1, 2, 2, 2, 4, 4, 4, 8, 8, 8 where 1, 2, 4, and 8 represents the number of complete heart cycles prior to acquiring the next subsequent image. The sequence above would take 45 heart cycles to complete and would produce 12 images.  
         [0095]    Select pushbutton  771  is associated with logic that initiates a secondary interface that enables a diagnostician to identify one or more specific images from the triggered sequence on a frame by frame basis for comparision. A default mode selects each of the triggered images. The diagnostic image loops can then be observed to derive tissue reperfusion functions for the tissues-of-interest. The DIMS  100  could be programmed to use this original image loop with varying delays between subsequent images and create a diagnostic loop which plays back the images as if they were acquired in real-time. In this way, the DIMS  100  greatly assists a diagnostician in the task of comparing the triggered myocardial tissue opacification loops.  
         [0096]    The various functions associated with segment pushbutton  767 , compare pushbutton  769 , and select pushbutton  771  are applicable to both real-time image loops as well as triggered image loops.  
         [0097]    Those skilled in the art will understand that while the sample diagnostic-image panels in FIG. 7A are shown in a side-by-side orientation that alternative image orientations are possible. For example, a diagnostician may prefer to have paired images displayed in a vertical arrangement, or when it is desired to display various images acquired from four distinct stress stages, the operator may elect to observe the diagnostic images in a 2×2 arrangement (i.e., with a diagnostic image in each corner of the display).  
         [0098]    [0098]FIG. 7B illustrates an alternative embodiment of a diagnostic image viewer  760  that can be programmed to present a plurality of diagnostic images in accordance with the observation preferences of a diagnostician of the image-management system  120 . As shown in FIG. 7B, diagnostic-image viewer  760  is a GUI that includes a pull-down menu bar  762  and a plurality of iconic task pushbuttons  764 . The GUI includes a left-side diagnostic-image panel  770 , a center diagnostic-image panel  780 , and a right-side diagnostic-image panel  790 . The left-side diagnostic-image panel  770  includes a diagnostic image of tissue(s) of interest (e.g., a slice of a patient&#39;s heart), as well as a host of patient conditions  724  and imaging parameters  726  as observed when the respective images were acquired. As illustrated, patient conditions  724  include a patient stress stage and a portion of the patient&#39;s heart cycle. In the example, the diagnostic image of the tissue(s) of interest was observed when the patient was in stress stage II.  
         [0099]    The center diagnostic-image panel  780  includes another image in the same image acquisition mode, image orientation, and portion of the heart cycle. The center diagnostic-image panel  780  also includes patient conditions  724  and imaging parameters  726  as observed when the respective image was acquired. In the example the diagnostic image of the tissue(s) of interest was observed when the patient was in stress stage III.  
         [0100]    Similarly, the right-side diagnostic-image panel  790  includes another image in the same image acquisition mode, image orientation, and portion of the heart cycle as the diagnostic images in the image panels to the left. The right-side diagnostic-image panel  790  also includes patient conditions  724  and imaging parameters  726  as observed when the respective image was acquired. In the example, the diagnostic image of the tissue(s) of interest was observed when the patient was in stress stage IV.  
         [0101]    Diagnostic-image viewer  710  also includes a plurality of functional pushbuttons labeled “step,” “loop,” “clear,” “print,” “view,” and “stop.” The various functional pushbuttons can be programmed to enable diagnostic-image viewer control with each of the respective functional pushbuttons operating as described above with regard to the GUI illustrated in FIG. 7A. It should be understood that the various functional pushbuttons provides a diagnostician flexibility when observing the various diagnostic images acquired during a patient examination.  
         [0102]    For example, if in addition to wall motion images a technician acquires images with myocardial tissue opacification to permit a diagnostician to observe myocardial vessel perfusion of contrast agents, the diagnostician may desire several different ways to display and compare the various images. The diagnostician may want to compare heart wall motion. The diagnostician may want to compare images with myocardial tissue opacification with other like acquired images from a different view angle (i.e., a different transducer position and orientation). The diagnostician may also want to compare images with myocardial opacification with images containing heart wall motion. The image-management system  120  of the DIMS  100  enables a diagnostician to configure and store multiple diagnostic image arrangements along with the imaging parameters and patient conditions observed at the time the images were acquired. The DIMS  100  also enables a diagnostician to quickly cycle through the various choices.  
         [0103]    Generally, diagnosticians do not prefer to view heart wall motion images in the same fashion as images containing myocardial tissue opacification. One preferred method of observing image loops of these different types of images is to have them start together and run in sequence as they were acquired. Some myocardial tissue opacification image loops are acquired in real time. Some others are controllably triggered as is the case with contrast agent destruction and observation of the tissues of interest as the blood supply reperfuses the tissues with contrast agent. With real time images, diagnosticians may desire to locate an image or frame where contrast agent destruction occurred and to define that image as the first image in the image loop. Image manager  416  is programmed to automatically define the first image in an image loop.  
         [0104]    The diagnostic image viewer  760  includes additional control interfaces that enable a diagnostician to modify various preferred arrangements of the diagnostic images. The additional control interfaces include systolic pushbutton  773 , diastolic pushbutton  775 , and cycle pushbutton  777 . Systolic pushbutton  773  is associated with logic that identifies and displays diagnostic images acquired in synchronization with the systolic portion of the patient&#39;s heart cycle. Diastolic pushbutton  775  is associated with logic that identifies and displays diagnostic images acquired in synchronization with the diastolic portion of the patient&#39;s heart cycle. Cycle pushbutton  777  is associated with logic that displays diagnostic images acquired over the entire heart cycle.  
         [0105]    The additional control interfaces may be used when observing wall motion image loops. When comparing diagnostic images acquired over the systolic or diastolic portions of the patient&#39;s heart cycle, image manager  416  is programmed to synchronize selected image loops acquired over various stages of patient stress. Consequently, image loops acquired with different patient heart rates may be coordinated to start and stop with the same event in the patient&#39;s heart cycle. Synchronization of diagnostic images acquired over various stages of stress (i.e., patient heart rates) enables a diagnostician to compare tissue movement throughout the patient&#39;s heart cycle over different stages of stress.  
         [0106]    It should also be understood that while the various examples illustrated and described above include two-dimensional images, the image manager  416  can be programmed to apply the display techniques using three-dimensional images as well. Furthermore, it should be understood that while the various control pushbuttons (e.g., pushbuttons  749  through  771 ) have been illustrated and described in association with the diagnostic image viewer of the general-purpose computer  131  the controls may be integrated with the DIAS  110 .  
         [0107]    [0107]FIG. 7C illustrates a way that the DIMS  100  can arrange a series of diagnostic images to provide another diagnostic perspective that may prove useful when the diagnostician is interested in a particular area of the patient&#39;s anatomy. DIMS  100  can identify and arrange a series of diagnostic images each acquired under a given stage of stress but from slightly different view angles. As illustrated in FIG. 7C the diagnostic image viewer  792  tiles diagnostic images  770   a  through  770   x . Scroll pushbutton  793  is associated with logic that will move subsequent images in the series to the front of the stack for observation for a controllable period of time until the series of images acquired from each available view angle is complete. Thumbnail pushbutton  795  is associated with logic that creates the display mode illustrated in FIG. 7D.  
         [0108]    As illustrated, the diagnostic image viewer  794  displays images  770   a  through  770   d . As described above, each of the separate images include a particular view of a patient&#39;s heart with each of the views having a slightly different acquisition perspective. It should be appreciated that the number of separate thumbnail images ( 770   a - 770   d  shown) may vary depending upon the relative size of the display monitor to the operator desired size of the each thumbnail in the series. Overlay pushbutton  797  is associated with logic that returns to the image overlay display mode illustrated in FIG. 7C.  
         [0109]    Reference is now directed to FIG. 8, which illustrates a flowchart describing a method for improved diagnostic-image displays  800  that may be implemented by the DIMS  100  of FIG. 1. As illustrated in FIG. 8, the method for improved diagnostic-image displays  800  begins with acquiring images from a patient study or examination as indicated in data operation  802 . In operation  804 , an operator of the DIMS  100  is identified. In operation  806 , the particular diagnostic imaging test type is identified. Next, as indicated in query  808 , the DIMS  100  may determine if an operator display preference has been previously stored by the identified operator for the identified study type. When an operator preference exists as indicated by the flow control arrow labeled, “YES” the DIMS  100  retrieves the operator&#39;s display preference parameters for the identified study as indicated in operation.  
         [0110]    Otherwise, when an operator preference has not been previously identified, the DIMS  100  responds by entering the display preference editor as illustrated in operation  812 . Once the diagnostician has indicated those images to be arranged and display preferences, the DIMS  100  responds by generating the display as illustrated in operation  814 . The DIMS  100  also responds by identifying appropriate images from the image store as indicated in operation  816 . Thereafter, as illustrated in operation  818 , the DIMS  100  forwards the identified diagnostic images in the diagnosticians preferred arrangement for observing images acquired via the identified test.  
         [0111]    It should be emphasized that the above-described embodiments of the diagnostic image-management system and its various components are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the system and method for improved diagnostic image displays. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the principles of the invention. For example, the control interfaces illustrated in FIGS.  7 A- 7 D and described above may be integrated as physical pushbuttons, selector knobs, thumb wheel interfaces, etc. with the DIAS  110 . Those skilled in the art will understand that these control interfaces may be additional and/or an alternative embodiment to the graphical-user interface(s) described above. All such modifications and variations are intended to be included herein within the scope of this disclosure and are protected by the following claims.