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.