[Automated image processing by PACS as a simple tool for designing craniotomy; synthesis of sagittal reconstructed CT images and cerebral angiograms].

Software has been developed to produce sagittal images of the brain recontracted from axial CT slices and automatically superimpose them on the lateral views of cerebral angiograms. A commercially available system for digitization, processing, display and computer storage of film radiographs (EFPACS-500) was used in the present studies. Axial CT scans are obtained in either 3, 5 or 10mm thicknesses parallel to the base line at the 10 degree angle to the OM line, and processed into the digital storage. Plain skull films and subtracted angiograms, on which two reference points on the same base line for superimposition were marked prior to processing, are also digitized and stored in the optical disk. On each CT slice, the ratio is calculated of a lesion's longitudinal length to the midsagittal distance of the head. By simply adjusting a linear cursor, which is parallel to the base line, to the highest and the lowest levels of the lesion, the sagittal image with the lesion clearly depicted is automatically reconstructed. And on this image an angiogram can be superimposed automatically simply by indicating two reference points on the base line on both images. The resulting images have markedly facilitated simple designing of craniotomy for intracranial lesions by graphically indicating their locations along with cerebral vessels in a lateral view.