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Biomedical subjects

W P Callahan

Publications and source records attributed to W P Callahan.

12 recordsLinked to original sources
PubMed1981

Temporal bone: comparison of pluridirectional tomography and high resolution computed tomography.

The recent introduction of high resolution computed tomography (CT) capable of resolving delicate bony structures such as the temporal bone marks another significant advance in diagnostic imaging. This study was designed to compare the integrity of these new CT images, standard CT images, and conventional complex motion tomographic images against contact radiographs of sliced anatomic specimens. Temporal bones of three frozen cadaver heads were studied with complex motion tomograms at 1 mm intervals and contiguous CT scans at 1.5 mm intervals in axial, coronal, and sagittal projections. The heads were physically sectioned at 2 mm intervals in planes corresponding to the radiographic planes using a precise indexing and sawing system. The tomographic images were compared for information content to contact radiographs of the anatomic specimen sections. Conventional tomographic images and expanded number range target reconstruction CT images proved to be highly accurate. Standard CT reconstruction images were not. The probable clinical effectiveness of each method is discussed.

Cadaver↗
PubMed1980

Linear vs. pluridirectional tomography of the chest: correlative radiographic anatomic study.

The basic imaging capabilities of 15 degrees linear, 30 degrees linear, hypocycloidal, and trispiral tomographic movements were compared using a fresh frozen human cadaver. Large numbers of tomograms, 100 with each tomographic movement, were compared as a motion study developed by copying the four tomographic series on movie film. In addition, the integrity of the tomograms was compared with radiographs of representative 2 mm coronal sections sawed from the fresh frozen thorax specimen. The study demonstrated the theoretical conclusion that a linear tomogram is not a sectional image and does not truthfully represent the planar anatomy of the intended layer. The pluridirectional tomograms, on the other hand, do accurately depict the anatomic section. The more general use of pluridirectional tomographic techniques in the chest is encouraged and should be used as the basis for comparing conventional tomographic imaging capabilities to other new modalities, particularly computed tomography.

Humans↗