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United States National Library of Medicine National Institutes of Health

Fact Sheet
The Visible Human Project®


The National Library of Medicine (NLM) has seen an increasing use of electronic images for clinical medicine and biomedical research. The Visible Human Project was established in 1989 to build a digital image library of volumetric data representing complete, normal adult male and female anatomy.

Visible Human Male

The Visible Human Male data set, released in November 1994, consists of MRI, CT, and anatomical images. Axial MRI images of the head and neck, and longitudinal sections of the rest of the body were obtained at 4mm intervals. The MRI images are 256 by 256 pixel resolution with each pixel made up of 12 bits of gray tone. The CT data consist of axial CT scans of the entire body taken at 1mm intervals at a pixel resolution of 512 by 512 with each pixel made up of 12 bits of gray tone. The approximately 7.5 megabyte axial anatomical images are 2048 pixels by 1216 pixels, with each pixel being .33mm in size, and defined by 24 bits of color. The anatomical cross-sections are at 1mm intervals to coincide with the CT images. There are 1,871 cross-sections for both CT and anatomical images. The complete male data set is approximately 15 gigabytes.

Higher resolution axial anatomical images of the male data set were made available in August 2000. Seventy-millimeter still photographs taken during the cryosectioning procedure were digitized at a pixel resolution of 4096 pixels by 2700 pixels. These images, each approximately 32 megabytes in size, are available for all 1,871 male color cryosections.

Visible Human Female

The Visible Human Female data set, released in November, 1995, has the same characteristics as the The Visible Human Male. However, the axial anatomical images were obtained at 0.33 mm intervals. Spacing in the "Z" dimension was reduced to 0.33mm in order to match the 0.33mm pixel sizing in the "X-Y" plane. As a result, developers interested in three-dimensional reconstructions are able to work with cubic voxels. There are 5,189 anatomical images in the Visible Human Female data set. The data set size is approximately 40 gigabytes.


The Visible Human data sets are designed to serve as a reference for the study of human anatomy, to serve as a set of common public domain data for testing medical imaging algorithms, and to serve as a test bed and model for the construction of network accessible image libraries. The Visible Human data sets have been applied to a wide range of educational, diagnostic, treatment planning, virtual reality, artistic, mathematical, and industrial uses by nearly 2,000 licensees in 48 countries. Several applications have been developed at the National Library of Medicine or under the direction of the National Library of Medicine. These applications include:

Last reviewed: 02 April 2008
Last updated: 02 April 2008
First published: 01 January 1996
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