William M. Kelly

Magnetic Resonance Scanning in Orbital Tumor Diagnosis

We have compared the accuracy of magnetic resonance scanning (MRI) versus computed tomography (CT) in the differentiation of lateral orbital masses. The MRI results did not improve our ability to accurately diagnose malignant epithelial and lymphoid tumors.

Intra-arterial DSA: early experience with a 10242 matrix

SummaryTwenty patients were studied with intraarterial digital subtraction angiography (IA DSA), utilizing a 10242 matrix memory. Acquisition of the images was through a prototype television camera incorporating a finely focused electron beam. In five cases, comparison between a 512×512 (5122) matrix acquisition and a 1024×1024 (10242) matrix acquisition mode was made, with injections occurring in the same vessel in the same patient. The clinical material demonstrated no significant improvement in image quality at the 41/2 as well as the 6 inch image intensifier (II) modes. However, the 10242 matrix combined with the 9 inch II mode showed foci of disease and normal anatomy with detail not always seen on the 9 inch II when a 5122 matrix was used. In no case, however, was the basic diagnosis missed with the 5122 matrix. Spatial resolution, as measured from lead bar test pattern images, demonstrated that the 10242 matrix allows a 70% or greater improvement in spatial resolution over the 5122 for the 41/2, 6 and 9 inch II modes. For a given mode the radiation dose was held constant for the two matrix sizes.