Magnetic resonance images of 128 patients with compressive lesions of the cervical spinal canal were reviewed to determine whether a high signal intensity lesion within the spinal cord was present on T2 and proton density weighted spin echo images. Such high signal intensity was observed in 24 cases or 18.8%. The incidence was higher in herniated disk (32.4%), atlanto-axial dislocation (28.6%), and ossification of the posterior longitudinal ligament (22.7%), whereas the abnormality was found sporadically in cervical spondylosis and vertebral body tumors. The high intensity lesion on T2 weighted images was generally observed in patients with constriction or narrowing of the spinal cord. The lesion was not demonstrated on T1 weighted spin echo images. Spinal cord constriction or localized narrowing seemed to be the most important predisposing factor in producing such a high signal intensity. The pathophysiologic basis of such an abnormality was presumed to be myelomalacia or cord gliosis secondary to a long-standing compressive effect of the spinal cord.
The iliac and subclavian arteries and their distal branches were studied by digital subtraction angiography (DSA) in 79 patients and the results compared with conventional angiograms for 35 patients. Techniques, results, advantages and disadvantages are described. DSA (both intravenous and intra-arterial) looks very promising in the diagnosis of peripheral vascular disease.
Stereoscopic DSA is performed with alternate exposures from a twin focal X-ray tube (6,5 cm focal separation). Excellent intravenous and intra-arterial DSA images of the cerebral vessels are obtained with separation of overlapping parts of the normal and abnormal vasculature. The clinical value of DSA has been enhanced by use of stereoscopic DSA.
Stereoscopic technique was applied to digital subtraction angiography (DSA) with alternate exposures from twin focus spots (6.5-cm separation) of an x-ray tube. Correct identification of two crossed aluminum wires was obtained more than 90% of the time when there was separation of more than 5 mm. Excellent clinical images of intravenous as well as intraarterial DSA have been obtained, and the clinical value of DSA was enhanced by application of the stereoscopic technique.
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