Vascular anatomy and disorders of the lumbar spine and spinal cord.

The design and interpretation of MR imaging studies of patients with suspected spinal vascular disease are based on a knowledge of arterial and venous anatomy. This article describes the major intradural vessels and their appearance on spin-echo MR images and gadolinium-enhanced MR angiography. Current gadolinium-enhanced MR techniques primarily detect veins, which may be increased in apparent number, size, or tortuosity in the pathological conditions discussed. These characteristics of abnormal veins have yet to be quantified, and differentiation between normal and abnormal is sometimes difficult. Familiarity with the appearance of normal veins on MR angiography facilitates recognition of abnormal vessels and thus the formulation of a more accurate differential diagnosis in the patient with a conus or cauda equina lesion. In the future, gadolinium-enhanced 3D MR angiography may achieve adequate spatial and temporal resolution to differentiate spinal arteries from spinal veins. This differentiation could further simplify the diagnosis of vascular lesions, depending or the complexity of the vascular pattern observed. Also, the combination of MR angiography and diffusion imaging of the cord may finally provide the information needed for characterization by MR imaging of clinically suspected arterial infarction.