The role of magnetic resonance angiography in the diagnosis of subclavian steal.
OBJECTIVE
To compare magnetic resonance angiography (MRA) with digital angiography for diagnosis of subclavian steal syndrome.


METHODS
A comparison study between MRA and digital contrast arteriography was carried out in 10 patients with suspected subclavian steal syndrome. Two of these patients were studied by MRA before and after percutaneous transluminal angioplasty (PTA). MRA was obtained on a 1.5 tesla superconductive magnet with linear head coil using a fast low angle shot (FLASH 2D) sequence in the axial plane as well as a fast imaging with steady state precession (FISP 3D) with velocity compensation gradient echo sequence in the coronal plane. The coronal images were used as source data for the construction of projection images with the use of a maximum-intensity pixel algorithm. The images were rotated from -45 degrees to 45 degrees in 15 degrees steps.


RESULTS
All 10 patients had evidence of proximal subclavian artery obstruction and flow reversal in the ipsilateral vertebral artery. On MRA, consistent visualization of the affected vertebral artery in the FLASH 2D sequences and nonvisualization in the FISP 3D sequences was interpreted as an indirect sign of subclavian steal. The subclavian artery obstruction could not be assessed due to field size limits of MRA.


CONCLUSIONS
MRA allows determination of flow reversal in the diagnosis of subclavian steal.
Carriero
A
A
Department of Radiology, University G. D'Annunzio Chieti SS. Annunziata Hospital, Italy.
Salute
L
L
Tartaro
A
A
Iezzi
A
A
Dragani
M
M
Tamburri
L
L
Bonomo
L
L
D000328:Adult; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008297:Male; D013349:Subclavian Steal Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging