Radiological evaluation of paragangliomas of the head and neck.

Paragangliomas can be differentiated angiographically from most other tumors in the head and neck by their profuse vascularity; specific classification is based on their position and displacement of adjacent vessels. Subtraction usually aids in diagnosis. In most cases, bilateral carotid angiography should be performed, since the ipsilateral carotid artery may have to be ligated and an asymptomatic contralateral tumor may also be found during surgery. Studies of multiple vessels will often show an additional blood supply. Computed tomography can demonstrate the tumor's vascular nature and position and is valuable in follow-up after radiation therapy.

CT of the spine.

The level of CT section in the lumbosacral region may be correlated with routine AP views of the spine using a reference plane constructed according to the distance between the iliac crests. CT scans of the spine in 100 patients have been analyzed. The majority of these cases consisted of primary or secondary bone or soft-tissue tumors. CT examination was valuable to supplement plain films and/or myelograms in evaluation of the extent of pathology. It was also useful in the work-up of patients with malignant tumors whose other studies were equivocal.

Computer-assisted tomography of the knee.

The potential contributions and limitations of computer-assisted tomography of the knee have been analyzed. The knee was examined in the transaxial, sagittal, semi-sagittal and coronal planes. The positioning for obtaining intra-articular detail is outlined, and the indications are discussed. Delineation of the cruciate ligaments is remarkably clear and clinically applicable. The menisci can be demonstrated, but improvement in spacial resolution and changes in the physical construction of the scanner will be required to permit an adequate clinical evaluation.