ct scan reading center Ann Scherzinger, PhD, Director The CT Scan Reading Center conducts multiple fat and muscle density studies involving the CT scan data of the abdomens and thighs from patients nationwide. The abdominal scans are usually taken at the levels of L2/L3 and L4/L5 disk spaces and the thighs scans are taken at center of the femur.     Figure 1: CT scan plane positioned at lumbar 4-5 level disk space (indicated by line on AP scout above left). Figure 2: Axial CT scan at lumbar 4-5 level disk space (above right). Patients for the studies are chosen by age, race, family members, or personal of risk to a fat related disease such as diabetes. For some studies, the participants are split into 2 groups, in which one group is administered a drug such as triglitrizone and one group is not. Sometimes patients of one group do exercise while the other group does not. The data is then checked for quality, pathology and analyzed. Analyzing the data requires a program called IDL which allows a selection of a fat, muscle, or bone to be calculated for the number of pixels. The pixels are measured by area, density, standard deviation and range.     Figure 3: Abdominal Axial CT scan before (above left) and after (above right) analyzing: visceral fat (dark pink) is separated from subcutaneous fat (light pink). A region of interest is selected to compare the fat and muscle density ratio of the region of interest selection against the whole body selection.   Figure 4: Region of interest selected (above left). Figure 5: Region of interest selected vs. whole body selected. (above right).     Figure 6: Fat and muscle histograms are generated from region of interest and whole body selections (above). Primarily, the area of study is the visceral fat in the abdomen because the way fat is distributed in each individual can lead to answers concerning why for example, some people are more prone to diseases such as Diabetes Type II. After the subjects have been analyzed, the study may reoccur a few years later to re-scan original patients at the same levels in order to compare fat distribution changes. The multiple visit patient data should prove helpful and interesting in the upcoming study of liposuction patients when looking at fat distribution and the regeneration of fat cells. How does all this fat data relate to the Visible Human Project? Currently, the Visible Human is being used to look at different kinds of fat that are not easily distinguishable in CT scans. The movie below shows the outline of fat and muscle distribution of a study patient's CT scan (left). This distribution is similar to that of the Visible Human Male. A reconstruction of what the fat would look like in full color of the patient is shown at the end of the morphing process of the Visible Human Male combined with the patient (right).     (click on image to view movie) Figure 7: Morphing process of the fat and muscle distribution of a study patient and Visible Human Male (above). ct scan reading center studies Women in the Southside Health Project (WISH), RUSH University Medical Center, Chicago, Illinois, 2002-2003 Biological Effects of DHEA in the Elderly, Dehydroepiandrosterone (DHEA), University of Colorado Denver, Denver, Colorado, 2001-2003 Modulation of visceral fat by estrogens after menopause (EAM), University of Colorado Denver, Denver, Colorado, 2001-2003 Health, Aging and Body Composition Study (Health ABC), University of California, San Francisco, 1998-2000, 2002-2003 The National Insulin Resistance Atherosclerosis Family Study (IRAS), Wake Forest University School of Medicine, Winston-Salem, North Carolina, 1999-2002 The Diabetes Prevention Program (DPP), George Washington University, Rockville, Maryland, 1999-2002 The Coronary Artery Disease Risk Development in Young Adults (CARDIA) study, University of Alabama at Birmingham, 2000-2002