Three-dimensional display of cardiac structures using reconstructed magnetic resonance imaging

Construction of a three-dimensional anatomical database of the human fetal heart

The objective of this study was to establish an anatomical atlas and a three-dimensional model of the fetal heart. To do this, we created a 60-microm cross-sectional image database of the heart of a Chinese male fetus. A 31-week stillborn fetus with no congenital defects was used as the model. All thoracic organs were removed from the thoracic cavity after formalin fixation and then frozen at -25 degrees C for 2 h. Frozen serial sections, 60-microm thick, were prepared and macroshot with a digital camera to obtain image data. Eight hundred seventy-one cross-sectional photos of the fetal heart were made at a resolution of 3888 x 2592 pixels. The atrioventricular cavity, as well as other fine structures, was revealed in the images, showing a clear boundary between the peripheral tissues. This rich database showing the three-dimensional features and anatomy of the fetal heart will be useful for teaching, scientific research, and clinical applications.

Technical report on semiautomatic segmentation using the Adobe Photoshop

The purpose of this research is to enable users to semiautomatically segment the anatomical structures in magnetic resonance images (MRIs), computerized tomographs (CTs), and other medical images on a personal computer. The segmented images are used for making 3D images, which are helpful to medical education and research. To achieve this purpose, the following trials were performed. The entire body of a volunteer was scanned to make 557 MRIs. On Adobe Photoshop, contours of 19 anatomical structures in the MRIs were semiautomatically drawn using MAGNETIC LASSO TOOL and manually corrected using either LASSO TOOL or DIRECT SELECTION TOOL to make 557 segmented images. In a similar manner, 13 anatomical structures in 8,590 anatomical images were segmented. Proper segmentation was verified by making 3D images from the segmented images. Semiautomatic segmentation using Adobe Photoshop is expected to be widely used for segmentation of anatomical structures in various medical images.

A real time collaboration system for teleradiology consultation

Real time collaboration systems, in which participants share multimedia data and applications in real time, have attracted many researchers in recent years. A teleradiology consultation system based on the real time collaboration technology is presented in this paper. Under the platform-independence consideration, Java technologies are employed to construct the system. Applying this system, an off-duty on-call radiologist can make diagnoses and report easily by viewing the transferred images at home. Owing to the accessibility of image, all users can examine and manipulate images consistently such that a secluded hospital can be assisted to hold remote consultation. To reduce the network transmission time, the command-passing and local command execution techniques are utilized to achieve the screen synchronization. A pointer function is also developed to maintain the cursor consistency in a more efficient manner during consultation when a detail indication of the examined image is needed. Besides, a dialog window is also designed for on-line conversation. Since Java programs can run on heterogeneous platforms, the need for system maintenance and user training can be substantially reduced.

Computer-based three-dimensional visualization of developmental gene expression

A broad understanding of the relationship between gene activation, pattern formation and morphogenesis will require adequate tools for three-dimensional and, perhaps four-dimensional, representation and analysis of molecular developmental processes. We present a novel, computer-based method for the 3D visualization of embryonic gene expression and morphological structures from serial sections. The information from these automatically aligned 3D reconstructions exceeds that from single-section and whole-mount visualizations of in situ hybridizations. In addition, these 3D models of gene-expression patterns can become a central component of a future developmental database designed for the collection and presentation of digitized, morphological and gene-expression data. This work is accompanied by a web site (http://www.univie.ac.at/GeneEMAC).

An improved computer method to prepare 3D magnetic resonance images of thoracic structures

The mediastinal and cardiovascular anatomy is complex. We have developed a three-dimensional (3D) reconstruction system for the major mediastinal structures using magnetic resonance imaging data on a NeXT workstation. The program uses a combination of automatic and manual procedures to determine the contours of the cardiac structures. The geometric centers of the contours are connected by a 3D space curve, and the central axis of each cardiac structures is determined. The contours are projected on the perpendicular plane to the central axis and semiautomatically processed until the contours of one pixel are obtained. Then the surface rendering with transparency is performed. Compositing combines two images so that both appear in the composite, superimposed on each other. Demonstration of the various mediastinal lines and cardiovascular diseases by the composits of the partly transparent 3D images has promoted a better understanding of the complex mediastinal and cardiovascular anatomy and diseases.