The Visible Human Project was sponsored by the National Library of Medicine of the National Institute of Health. It's objective was to create a high resolution digital database of a human male and female for use in education and research. The digital database was accumulated in the cross-sectional plane. The Visible Male images were acquired first and derived from the body of a 39 year-old executed murderer. The Visible Female images were derived from a 59 year-old woman who died of coronary artery disease. Details of the Visible Human Project are available at the National Library of Medicine's web site (http://www.nlm.nih.gov). In brief, the cadavers were perfusion fixed and frozen at -85 degrees C. At regular intervals (1.00 mm for the male and 0.33 for the female) body tissue was removed by a "cryosectioning" process conducted in the cross-sectional plane. As a layer of body tissue (a 1.0 or 0.33 mm "cryosection") was removed, the underlying and now exposed cross-sectional surface of the body was digitally photographed. The Visible Male resulted in 1,878 digital cross-sectional images; the Visible Female slightly over 5,000 images.
Unfortunately the upper limbs of neither the male nor female were placed in the anatomical position during the sectioning process but rather the limbs were pronated and laid at an angle across the abdomen. Thus from approximately the elbows distally the upper limb images are in fact not cross-sections but oblique images. In addition, the feet of both specimens were slightly plantar-flexed and thus not sectioned in the cross-sectional plane as truly defined by the anatomical position. Variations from the cross-sectional plane are noted with the affected images. Finally, bear in mind that cross-sectioned cadaveric images from the Visible Human have a higher resolution than CT scans, even CT scans from living persons given contrast materials. As such not all structures identifiable in a cadaveric specimen are visible in a CT scan; here ones anatomical knowledge facilitates the interpretation of radiological data, e.g. knowledge of the presence of a nearby nerve not visible in CT but potentially affected by a nearby pathology.