Spinal intradural vessels, which are on the order of 1 mm in diameter, are better detected and displayed on contrast-enhanced MR angiographic images than on spin-echo MR images. This improved characterization of the spinal vasculature can help narrow the differential diagnosis and guide further diagnostic studies or treatment in patients with radiculopathy or myelopathy. The interpretation of MR angiograms requires a knowledge of vascular anatomy, that is, of the medullary arteries and veins, the anterior spinal artery, and the anterior and posterior median veins. The most useful application to date has been in screening for spinal dural fistula. The standard 3D MR angiography technique detects enlarged, tortuous intradural veins, including the dominant medullary vein into which the fistula drains, and the fast 3D technique may also show the fistula. The location of the fistula can thus be determined noninvasively, allowing more efficient evaluation with catheter angiography. In patients who have been treated by surgery or embolization for spinal vascular malformation, fistula, or vascular tumor, MR angiography complements the routine MR imaging study, because the appearance of the intradural vessels can be assessed and compared with the pretreatment appearance. Additional studies documenting the appearance on MR angiography of intradural vessels in cases of spinal tumor or inflammation are needed to determine the specificity of MR angiography findings. Further development of the fast 3D technique offers the possibility of improved temporal resolution while maintaining high spatial resolution, so that normal arteries and veins may be distinguished. Only by establishing the MR angiographic appearance of normal arteries and veins, can an abnormal appearance be defined with confidence. For example, variations in the size, trajectory, location, number, and extent of visible vessels that differ significantly from the normal appearance may then be used to identify abnormal vascular patterns with greater confidence - assuming that the variability in spinal cord blood supply and drainage is not so great as to preclude differentiation. With technical improvements and additional clinical experience, MR angiography, in combination with routine MR imaging, promises more accurate noninvasive diagnosis of spinal vascular disease.
|Original language||English (US)|
|Number of pages||17|
|Journal||Magnetic Resonance Imaging Clinics of North America|
|State||Published - Sep 18 2000|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging