Virtual organ unfolding for visualization

A system and method for organ image unfolding for feature visualization are provided, where the system includes a processor, an imaging adapter in signal communication with the processor for receiving organ scan data, a modeling unit in signal communication with the processor for fitting a model to the scan data, and an unfolding unit in signal communication with the processor for unfolding the 3D modeled scan data; and the corresponding method includes segmenting an outer surface of the organ, parameterizing a 3D model of the organ, ray-casting from the center of the organ to the surface of the 3D model, and unfolding the 3D model of the organ in correspondence with the ray-casting.

BACKGROUND

Medical image scanning data, for example, is typically obtained in the form of slices in various types of imaging modalities. These slices are then stacked to form a three-dimensional (“3D”) volume. This volume must then be visualized and segmented.

In current approaches to medical image scanning, researchers have developed a wide variety of segmentation techniques for isolating heart coronary arteries. Research in this field is motivated by the high number of patients suffering from coronary artery disease. Heart coronary arteries are typically difficult to segment because of their size and proximity to the surface of the heart and blood pool.

Accordingly, what is needed is a system and method capable of Heart Unfolding for Coronary Visualization. The present disclosure addresses these and other issues.

SUMMARY

These and other drawbacks and disadvantages of the prior art are addressed by an apparatus and method of heart unfolding for coronary visualization.

A system for organ image unfolding for feature visualization includes a processor, an imaging adapter in signal communication with the processor for receiving organ scan data, a modeling unit in signal communication with the processor for fitting a model to the scan data, and an unfolding unit in signal communication with the processor for unfolding the 3D modeled scan data.

A corresponding method for organ image unfolding for feature visualization includes segmenting an outer surface of the organ, parameterizing a 3D model of the organ, ray-casting from the center of the organ to the surface of the 3D model, and unfolding the 3D model of the organ in correspondence with the ray-casting.

These and other aspects, features and advantages of the present disclosure will become apparent from the following description of exemplary embodiments, which is to be read in connection with the accompanying drawings.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In accordance with preferred embodiments of the present disclosure, a system and method of Heart Unfolding for Coronary Visualization are described herein. The method allows a user to better visualize the heart coronaries and vessels on the surface of the heart.

In recent decades, researchers have developed a wide variety of segmentation techniques for isolating heart coronary arteries. Research in this field is motivated by the high number of patients suffering from coronary artery disease. Heart coronary arteries are typically difficult to segment because of their size and proximity to the surface of the heart and blood pool.

Because of the difficulty with segmentation, and because of the proximity of coronary arteries to the surface of the heart, a surface unfolding approach can be used to overcome the visualization problem to some degree. This technique provides a great improvement for visualization of the heart coronary arteries.

The presently disclosed method incudes “unfolding” the surface of the heart and creating a Maximum Intensity Projection (MIP) of this surface. The result is a 2D map of the surface of the heart, containing the peripheral vessels.

As shown inFIG. 1, a system for acquisition-time modeling and automated post-processing according to an illustrative embodiment of the present disclosure is indicated generally by the reference numeral100. The system100includes at least one processor or central processing unit (“CPU”)102in signal communication with a system bus104. A read only memory (“ROM”)106, a random access memory (“RAM”)108, a display adapter110, an I/O adapter112, a user interface adapter114, a communications adapter128, and an imaging adapter130are also in signal communication with the system bus104. A display unit116is in signal communication with the system bus104via the display adapter110. A disk storage unit118, such as, for example, a magnetic or optical disk storage unit is in signal communication with the system bus104via the I/O adapter112. A mouse120, a keyboard122, and an eye tracking device124are in signal communication with the system bus104via the user interface adapter114. A magnetic resonance imaging device132is in signal communication with the system bus104via the imaging adapter130.

A modeling unit170and an unfolding unit180are also included in the system100and in signal communication with the CPU102and the system bus104. While the modeling unit170and the unfolding unit180are illustrated as coupled to the at least one processor or CPU102, these components are preferably embodied in computer program code stored in at least one of the memories106,108and118, wherein the computer program code is executed by the CPU102. As will be recognized by those of ordinary skill in the pertinent art based on the teachings herein, alternate embodiments are possible, such as, for example, embodying some or all of the computer program code in registers located on the processor chip102. Given the teachings of the disclosure provided herein, those of ordinary skill in the pertinent art will contemplate various alternate configurations and implementations of the modeling unit170and the unfolding unit180, as well as the other elements of the system100, while practicing within the scope and spirit of the present disclosure.

Turning toFIG. 2, a flowchart for acquisition Heart Unfolding for Coronary Visualization according to an illustrative embodiment of the present disclosure is indicated generally by the reference numeral200. The flowchart200includes a start block210that passes control to a function block212. The function block212initiates a preliminary heart scanning session and passes control to an input block214. The input block214receives preliminary heart scan data and passes control to a function block216.

The function block216segments the heart's outer surface and passes control to a function block218. The function block218performs a fixed 3D model parameterization of the heart and passes control to a function block220. The function block220casts rays from the center of the heart to the surface of the 3D model, and passes control to a function block222. The function block222unfolds the 3D model and passes control to an end block224.

Turning now toFIG. 3, a 3D MIP texture on an isosurface volume is indicated generally by the reference numeral300. The 3D MIP texture300provides a visualization for heart unfolding.

As shown inFIG. 4, a heart unfolding visualization is indicated generally by the reference numeral400. Unfolding the surface of the heart brings a new way to visualize the coronaries. The unfolding visualization400shows the correlation between an MIP410(above) and an unfolded heart surface420(below).

Turning toFIG. 5, a common VRT visualization is indicated generally by the reference numeral500. In this exemplary embodiment, a graph cut algorithm is used to get a hollow heart volume that will determine the surface to be unfolded. The VRT visualization500is shaded by a 3D Syngo card in this example.

Turning now toFIG. 6, common MIP visualization is indicated generally by the reference numeral600. Here, the regular MIP view shows that the coronaries are obstructed by bright tissues. The MIP visualization600of the thick surface is shown by a 3D Syngo card in this example.

As shown inFIG. 7, a new 3D model visualization is indicated generally by the reference numeral700. The new 3D model visualization700shows a 3D MIP texture mapped on an isosurface volume.

Turning toFIG. 8, another new 3D model visualization is indicated generally by the reference numeral800. Here, The new 3D model visualization800shows fitting an ellipsoid810to the surface of the heart820, projecting an MIP texture on the ellipsoid810, visualization of the 3D model, and fitting the ellipsoid810(left) or a sphere830(right) to the surface of the heart820.

Turning now toFIG. 9, a 3D model visualization is indicated generally by the reference numeral900. The 3D model visualization900indicates actual results of an exemplary embodiment heart unfolding method as applied to real data. As will be recognized by those of ordinary skill in the pertinent art, such results have a greater clinical value than was achievable with prior methods.

This exemplary method brings an improved visualization technique for the heart coronaries, as well as vessels on the surface of the heart. The basic principle is to “unfold” the surface of the heart and create a MIP of this unfolded surface. The resulting 2D map of the surface of the heart contains highly contrasted vessels.

Thus, the exemplary technique used for unfolding the surface of the heart is accomplished in four steps: 1) Segmentation of the heart's outer surface; 2) Fixed 3D Model parameterization of the heart; 3) Casting rays from the center of the heart to the surface of the 3D model (MIP filter can be applied here); and 4) Unfolding of the 3D Model.

A graph cut algorithm as known in the art, for example, may be used to segment the outer surface of the heart. From the result of this segmentation, a distance map is created to evaluate the distance from each point on the volume to the segmented surface of the heart. Then, a known 3D model can be fit into the heart so that the surface of the heart fits the surface of the model. After this step, a ray is cast from the center of the heart to the surface of the 3D model. A profile curve is created while the ray propagates through the heart, and a response filter is applied to detect the eventual location of a vessel. If a location is found, then the algorithm displays the result on the surface of the 3D Model. As will be recognized by those of ordinary skill in the pertinent art, the unfolding of the 3D model is a widely-studied problem and several different algorithms can be used.

A preferred embodiment uses a sphere as 3D model and Maximum Intensity Projection (MIP) as the profile curve filter. Although alternate 3D models and ray filters may be used, some may adversely impact the quality of the results.

Thus, preferred embodiments of the present disclosure provide powerful heart unfolding tools for coronary visualization, enabling users to extract significant features and regions-of-interest. Preferred embodiments can serve as very useful acquisition-time modeling and automated post-processing tools in clinical applications.

These and other features and advantages of the present disclosure may be readily ascertained by one of ordinary skill in the pertinent art based on the teachings herein. It is to be understood that the teachings of the present disclosure may be implemented in various forms of hardware, software, firmware, special purpose processors, or combinations thereof.

It is to be further understood that, because some of the constituent system components and methods depicted in the accompanying drawings are preferably implemented in software, the actual connections between the system components or the process function blocks may differ depending upon the manner in which the present disclosure is programmed. Given the teachings herein, one of ordinary skill in the pertinent art will be able to contemplate these and similar implementations or configurations of the present disclosure.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present disclosure is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope or spirit of the present disclosure. All such changes and modifications are intended to be included within the scope of the present disclosure as set forth in the appended claims.