3D modeling of the cardiac anatomies is useful for enhancing ones understanding of the variations that may occur relative to an individual patient and/or disease state. Such models have been used to advance the anatomical understandings of medical students, residents, physicians, and/or cardiac device designers. For example, modeling in combination with clinical imaging can provide surgeons with physical representations of the patient's anatomy with which to plan complex surgeries.
Our lab has created a database of 3D models by reconstructing anatomies from magnetic resonance (MRI) and/or computed tomography (CT) scans using Mimics Software (Materialise, Leuven, Belgium). First, individual MRI and CT scans are obtained using methods described in the Static Imaging Methodologies section of the website. A given scan is then uploaded to Mimics, where we segment out anatomies based on their Hounsfield thresholds. Hounsfield thresholds quantify the radiodensity of a given tissue and can be used to isolate and segment out a specific anatomy, such as the left ventricle or epicardial fat. We have used these models to measure various anatomical parameters including cardiac chamber volumes and coronary vasculature arc lengths, branching angles, tortuousities, and diameters. We will continue to build this database of measurements to be used for device design for a variety of patient populations.
Many of these specimens have been categorized by the progression of the cardiac disease state they exhibit, usually a form of chronic heart failure (CHF). CHF is generally defined as a degenerative cardiac pathology in which the heart cannot adequately pump blood to the rest of the body. Two of the most common forms of CHF are ventricular hypertrophy and ventricular dilation. The most common causes of ventricular hypertrophy, the thickening of the ventricular heart muscle, are coronary heart disease, high blood pressure and heart valve disorders. However, hypertrophy can be the result of a genetic cardiomyopathy whereby the heart muscle thickens over time. The causes of ventricular dilatation, often a result of a specific cardiomyopathy where the heart chamber enlarges and the heart walls stretch and thin reducing the organs ability to pump blood efficiently to the rest of the body, are not as well understood. In most cases dilated cardiomyopathy is attributed to genetic disorders, coronary heart disease, diabetes, thyroid disease, infections, and alcohol or drug abuse. Although the majority of the heart specimens in the Visible Heart® library are from patients with CHF, some hearts still exhibit anatomical dimensions that would normally be associated with a healthy individual. These specimens often display cardiac pathologies such as coronary artery disease, myocardial infarctions or valve disease yet have not remodeled in the degenerative fashion associated with CHF.