[How reliable is the diagnosis of spinal angiomas in the myelogram?]

Using water-soluble contrast media for thoracic myelography vascular structures can be outlined within the subarachnoid space in about 30% as distinct and in another 30% as faint contrast filling defects. The localization corresponds to the results of anatomical studies demonstrating the largest vessels in the lower thoracic region and at the lumbar enlargement. The extreme variability of size and course of spinal cord vessels can cause difficulties in separating normal and angioma-like vascular pattern in myelographic examinations. Out of 100 unselected cervico-thoracic myelographies, examples of normal vascular patterns are given and compared to pathological findings of angiographically verified angiomatous malformations. The limitations of diagnostic reliability are given by anatomical factors like variability of vessel size or width of the subarachnoid space, by secondary spinal arachnitis or by the differentiation of cord tumours with vascular congestion. Furthermore, inadequate angiographic studies can result in misinterpretation of myelograms. In cases of negative arteriograms other affections leading to raised pressure in the azygos- or caval vein should be considered.