Left ventricle functional analysis can be performed using coronary CT angiography (CTA) images. In recent years it has been proposed that CTA imaging might also be used for myocardial perfusion assessment, by visually looking for hypoattenuated regions that may correspond to hypoperfusion. Assigning a detected lesion to a specific myocardial segment requires significant effort while the clinician matches the American Heart Association (AHA) standard myocardial segments to the anatomy of each patient. This article presents an interactive tool which, based on the existence of a previous left ventricle segmentation, automatically matches the lesions detected by the clinician to a myocardial segment and provides feedback over the image regarding the myocardial segments with detected lesions and their severity.

Abstract Coronary CT angiography is widely used in clinical practice for the assessment of coronary artery disease. Several studies have shown that the same exam can also be used to assess left ventricle (LV) function. Even though coronary CT angiography provides data concerning multiple cardiac phases, along the cardiac cycle, LV function is usually evaluated using just the end‐systolic and end‐diastolic phases. This unused wealth of data, mostly due to its complexity and the lack of proper tools, has still to be explored to assess if further insight is possible regarding regional LV functional analysis. Furthermore, different parameters can be computed to characterize LV function and though some are well known by clinicians others still need to be tested concerning their value in clinical scenarios. Based on these premises, we present several parameters characterizing global and regional LV function, computed for several cardiac phases over one cardiac cycle. The data provided by the computed parameters is shown using a set of visualizations allowing synchronized visual exploration of the different data. The main purpose is to provide means for clinicians to explore the data and gather insight over their meaning and their correlation with each other and with diagnosis outcomes.

Cardiac angiography using multiple detector row computerized tomography (MDCT) scanners provides 3D data concerning the heart and, in particular, the left ventricle (LV), for different cardiac phases along one cardiac cycle. Exploring this data for LV function analysis is not an easy task, given the amount of data and time involved in segmenting (or revising results provided by automatic segmentation methods) up to 12 cardiac phases. CardioAnalyser, a tool for 4D LV segmentation from MDCT data which provides a protocol to help perform LV segmentation of all cardiac phases available is presented. It uses an automatic segmentation algorithm along with a procedure which guides the user through the process. Its main goal is to reuse as much information as possible from one cardiac phase to the next in order to reduce segmentation time and the amount of user interaction.

The appropriate use of color in Visualization is a very important subject. The choice of the proper color scale to use with a particular data set is not just a matter of choosing the prettiest representation. Throughout the years researchers have studied this subject and managed to propose guidelines which help users along the process of color scale selection. This article presents a brief overview on the subject focusing on the desired properties for color scales, the guidelines that should drive their choice, the advantages of applying those guidelines, the experimental research work on the field, and the tools proposed to help non-expert users.

Polygonal meshes are used in many areas to model different objects and structures. Depending on their applications, they sometimes have to be processed to, for instance, reduce their complexity (simplification). This mesh processing introduces error, whose evaluation is important when choosing the kind of processing that is to be done for a particular application. Although some mesh comparison tools are described in the literature, little attention has been given to the way results are presented. A tool is presented which enhances the way users perform mesh analysis and comparison, by providing an environment where several visualization options are available and can be used in a coordinated way.