System and method for dynamic growing of a patient database with cases demonstrating special characteristics

A system and method for context-dependent data filtering for clinical decision support are disclosed. The system and method comprise determining values for characteristics of a present case, determining whether the present case is a special case based on the determined values, receiving input from a user verifying that the present case is the special case and saving the present case to a database containing a compilation of cases if the user verifies that the present case is the special case.

BACKGROUND

Breast cancer is one of the most common cancers and the second most frequent cause of cancer-related deaths among women in the United States. Dynamic Contrast-Enhanced MRI (DCE-MRI) screening is usually recommended in addition to mammography for high-risk women and it is increasingly used as a key staging tool for newly diagnosed breast cancer.

Clinical decision support (CDS) methods based on case-based reasoning (CBR) aid physicians' decision making by presenting previously diagnosed or treated cases that are similar to the case in question. A CBR-based CDS system will allow physicians to access a set of past cases that exceeds their own historical experience. For breast cancer diagnosis, it can aid in diagnostic interpretation of suspicious lesions with the potential to reduce unnecessary biopsies and delays in treatment. However, significant research challenges remain for CBR-based CDS for breast cancer.

SUMMARY OF THE INVENTION

A method for determining values for characteristics of a present case, determining whether the present case is a special case based on the determined values, receiving input from a user verifying that the present case is the special case and saving the present case to a database containing a compilation of cases if the user verifies that the present case is the special case.

A system having a memory storing a compilation of cases and a processing device determining values for characteristics of a present case and determining whether the present case is a special case based on the determined values, the processor further receiving input from a user verifying the present case is the special case and saving the present case to the memory if the user verifies that the present case is the special case.

A non-transitory computer readable storage medium storing a set of instructions executable by a processor. The set of instructions operable to determine values for characteristics of a present case, determine whether the present case is a special case based on the determined values, receive input from a user verifying that the present case is the special case and save the present case to a database containing a compilation of cases if the user verifies that the present case is the special case.

DETAILED DESCRIPTION

The exemplary embodiments may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The exemplary embodiments relate to a context-dependent data filtering for a clinical decision support system and method. In particular, the exemplary embodiments provide a system and method for filtering patient data based upon the context in which a user is interacting with the system to provide only the most relevant data to the user. Although the exemplary embodiments are described with respect to a patient suffering from breast cancer, it will be understood by those of skill in the art that the systems and methods of the exemplary embodiments of the present invention may be used in any healthcare setting such as, for example, cardio informatics and disease management.

As shown inFIG. 1, a system100comprises a processing device102that is connected to a plurality of user devices104-108via a communications network such as, for example, a wired/wireless LAN/WAN, an intranet, the Internet, GPRS, mobile networks, etc. The processing device102, as shown inFIG. 1, is a server comprising an evaluation manager114that performs calculations for each new case and a decision manager116that determines if the new case is a special case and, if so, provides a user (e.g., physician, administrator) with a recommendation to store the case.

The user devices104-108may be any wired or wireless computing devices that connect to and communicate with the processing device102, e.g., portable computing device, personal digital assistant (PDA), laptop computer, tablet, notebook, etc. The user devices104-108may include a user interface for displaying the processed information to the user and permitting the user to input information to the processing device102. For example, the user interface may be a graphical user interface displayed to the user on a display and permitting information to be entered via an input device. It will be understood by those of skill in the art that the system100may include any number of user devices104-108.

The storage device128comprises a database112of past cases that have previously been saved. As will be described in greater detail below, the database112includes information of all the case in the database112(e.g., statistical information including mean, standard deviation, kurtosis, and other quantitative information, etc.) that is needed to analyze new and past cases (e.g. whether the case is typical or deviant). These values are based on the calculations performed by the evaluation manager114for all the cases in the database. The database112also includes a record110for every patient that has a case saved in the database112. In order to perform calculations on a case, the evaluations manager114uses algorithms118which are stored in the storage device128. To enable the dynamic growth of the database, the database112is further connected to other information systems such as the institution's Radiology Information System (RIS), Hospital Information System (HIS), and Picture Archiving and Communication System (PACS). The system100may also be incorporated into any case-based retrieval or CDS system.

The following provides an example of the functionality of the system100that is specific to breast cancer. However, as described above, those skilled in the art will understand that the functionality described herein for the system100is not limited to breast cancer evaluations. The functionality described herein may also be applicable to other medical conditions such as other types of cancer, cardiovascular disease, orthopedic issues, stroke, trauma, etc.

Returning to the breast cancer example, most of the qualitative characteristics of the morphologic description of breast lesions are calculated on shape, margin, and internal enhancement of the lesions. As shown inFIG. 2, shapes of lesions include round202, oval204, lobular206, and irregular208. Margins includes smooth, spiculated, and irregular shapes. A lesion with spiculated or irregular margin and shape tends to be a malignant lesion. As seen inFIG. 3, common internal enhancement of lesions includes homogeneous302, heterogeneous304, rim enhancement306, and dark internal septation308. If the intensities of the voxels in a lesion are different and enhancement is non-uniform, the enhancement tends to be more heterogeneous304. Rim enhancement306of breast lesions of MR imaging is due to a combination of angiogenesis, distribution, and the degree of fibrosis. This results in a “black hole” of cell death. The thicker the rim (the white area of the lesion), the more likely the lesion is malignant. The appearance of rim enhancement showed a statistically significant association with malignant lesions and is a very useful indicator of the malignancy of the lesions. Dark internal septations308refer to non-enhancing septations in an enhancing mass. These look like black lines inside the lesion. They are typical of fibroadenomas, especially when the lesion has smooth margin or lobulated shape. The presence of internal septations and lobular shape is found to be highly predictive of benignity.

Each of these qualitative characteristics of the breast lesions may be assigned a quantitative value based on an appropriate scale. One exemplary scale may include a higher score for a qualitative characteristic that is more indicative of malignancy and a lower score for a qualitative characteristic that is more indicative of a benign lesion. However, any appropriate scale to assign quantitative values may be used. The calculations performed by the evaluation manager to assign the quantitative values are described in greater detail below.

FIG. 4shows an exemplary process carried out by the processing device102when a new case is presented to it. In step400, the processor calculates values for the lesion characteristics described above with respect toFIGS. 2 and 3. Based on these values, the processor determines, at step402, whether or not the present case is a special case (i.e. a case that would be beneficial to future diagnoses). If the present case does not have special characteristics, the decisions manager116does not make any recommendations to the user (step412). However, if the processor determines that the present case is a special case, the decision manager116recommends saving the present case to the database112, at step404. For example, the user devices104-108may include an application or a program that interfaces with the processor102such that the recommendation is sent from the processor102to the user devices104-108and is presented to the user on a user interface of the application displayed on a display screen of the user devices104-108. The decision to save the present case to the database112then lies with the user (step406). Via the user interface presented on the user device104-108, the user may enter a selection of whether or not to save the case to the database112. If the user does not wish to save the present case to the database, no changes are made to the database112(step414).

If the user decides to save the present case, the case is added to the database112(step408) for future retrieval and the database112is updated to reflect the addition of the new case (step410). When a case is added to the database112, both the image of the lesion and the calculated values are added. In addition, other identifying data for the case may also be added to the database112such as patient ID, sex, age, presenting date, family history, medical history, co-morbidities, diagnosis, treatments administered, etc. Any information that may be used to retrieve the case at a later time may be added to the database112. Furthermore, the updating of the database also includes recalculation or reapplying machine learning methods, such as artificial neural network for any or all of the parameters associated with the database such as the statistical parameters as a result of the adding of the new case to the database112.

It should be noted that the decision manager116may use general criteria for determining a special case or may also use individualized criteria based on a specific user (e.g., physician). More specifically, an individual user may have their own criteria for determining whether a case is a special case that they want to include in the database112. In such a situation, the user may identify to the decision manager116or provide criteria to the decision manager116those qualitative and/or quantitative characteristics that the user finds important. When the decision manager116identifies these characteristics in a new case, the decision manager116will make the recommendation to the user such as described in step404above. However, the decision manager116may also include generalized criteria (e.g., statistical criteria, classification criteria, etc.) that may be used by any number of users in order to identify special cases to be included in the database112. One example of statistical criteria may be the mean of rim thickness being greater than a pre-set value. However, those skilled in the art will understand that there are many more examples of statistical criteria and other types of machine learning techniques that may be used.

In addition, a user may have an individualized database112or may use a general database112. For example, a user may decide that they are only interested in looking at cases that they have identified as special for helping in future diagnoses. In such a situation, the system100may include an individualized database112that is specific to that user that is only populated with cases by that user. The individualized database112may also include other users' cases that were added by the first user. That is, the decision manager116may identify another user's case that may be interesting to the specific user and give the user the option of adding that case to the individualized database112. In the case of the general database112, the users are adding cases that may be retrieved by all users of the system100.

An exemplary calculation performed by the evaluation manager114on a new case will now be described. It is noted that the example calculation provided below is based on a morphological feature. However, it should be understood that similar calculations may be performed using non-image based features. Specifically, the features of interest may include any feature that the radiologist deems important, including non-morphological features such as genetics, family history, epidemiology, etc. For the purposes of providing an example calculation, a morphological feature will be selected. When a new case is presented to the processing device102, the shape of the lesion is determined. To distinguish lobular shapes from the other shapes, the evaluation manager114calculates the distance from each voxel on the surface of the lesion to the center of the lesion. Based on the calculated distance (radius), an array is generated. Other features, not described here, are calculated based on this array. As seen inFIGS. 5 and 6, the radii of the oval lesion have less variance than that of the lobular lesion because the oval lesion does not have as many leaves as the lobular shaped lesion. The evaluation manager114then determines the local maximum and local minimum of the array of radii. As seen inFIGS. 5 and 6, the total number of local maximums of the lobular lesion is greater than that of the oval shaped lesion. Furthermore, although the total number of local maximums of the irregular shaped lesion might be similar to that of the lobular shaped lesion, the variance of the local maximum and minimum of the lobular shaped lesion would most likely be less than that of the irregular shape. These features are independent of the size of the lesion.FIG. 7shows examples of the different features calculated for each new case presented to the processing device102in the case of breast cancer lesions.

After the shape and above-mentioned characteristics of the lesion are determined, the evaluation manager114characterizes the enhancement of the lesion in the present case. An exemplary simplified algorithm for this characterization is shown inFIG. 8. To characterize the rim enhancement and dark internal septation, the evaluation manager114first finds the lesion boundary and identifies heterogeneous regions (dark regions) inside the lesion. To differentiate between a white region and a black region, an iterative method is used to find a threshold value. Next, the largest isolated heterogeneous region, which is shown as a “black hole” of dead cells, is found. The boundary of this dark region is then found. The rim is the entire lesion minus the largest dark region, which is shown as a white area of the lesion. During this process, the features listed inFIG. 7are calculated. RimOrSeptationRatio is used to differentiate between rim enhancement and dark internal septation. Features starting with “homo” and “hetero” are used to differentiate between homogeneous regions and heterogeneous regions.

FIG. 9shows the result of the image processing of the two lesions with rim enhancement. The left column shows the original images902and906. The middle column shows the images903and907after finding the inner “black holes,” the rim is the white area inside the lesion. The right column images904and908has the gray edge showing the boundary of the “black hole” and the white edge showing the lesion boundary.

In another embodiment, during the automatic calculations of the features of a newly presented case, the processing device102can retrieve past cases with similar special characteristics to the present case. As described above, one of the reasons for saving cases to the database112is so that users may retrieve the case at a later time to aid in new diagnoses. Thus, when a new case is presented and its values calculated, one or more saved cases with similar values may be retrieved. The other identifying information that is stored for the saved cases (e.g., sex, age, etc.) may also be used by the physician to discriminate between the retrieved cases. For example, if the system100retrieves six similar cases, the physician may only desire to see those cases that are for a female over the age of 40. The identifying information may then also be used to retrieve the actual images for the saved cases. This retrieval can be from at least one of the RIS120, HIS122, and PACS124connected or included in the storage device128.

Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any number of manners, including, as a separate software module, as a combination of hardware and software, etc. For example, the evaluation manager114and the decision manager116may be programs containing lines of code that, when compiled, may be executed on a processor. The programs may be embodied on a non-transitory computer readable storage medium.

It is noted that the claims may include reference signs/numerals in accordance with PCT Rule 6.2(b). However, the present claims should not be considered to be limited to the exemplary embodiments corresponding to the reference signs/numerals.

It will be apparent to those skilled in the art that various modifications may be made to the disclosed exemplary embodiments and methods and alternatives without departing from the spirit or scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations provided that they come within the scope of the appended claims and their equivalents.