MIDDLE CEREBRAL-ARTERY STENOSES - ASSESSMENT BY MAGNETIC-RESONANCE ANGIOGRAPHY AND TRANSCRANIAL DOPPLER ULTRASOUND

Magnetic resonance angiography (MRA) findings of uni- or bilateral mid dle cerebral artery (MCA) stenosis were compared with results of trans cranial Doppler ultrasound (TCD) and digital subtraction angiography ( DSA). Eighteen patients with 22 MCA stenoses were selected by TCD crit eria. To evaluate the diagnostic accuracy of MRA, TCD and DSA, criteri a for classification of stenoses were established. MRA confirmed 21 MC A stenoses as revealed by TCD (n = 22). DSA did not demonstrate MCA st enoses in 6 cases diagnosed by TCD (classification grade I) and MRA. T he classification of MCA stenoses by MRA correlated with TCD in 11 (50 %) cases, while stenosis was underestimated by MRA in 3 (14%) and over estimated in 8 (36%) MCAs. Whereas the sensitivity of MRA for the dete ction of MCA stenoses compared to TCD and DSA findings was very high ( 100%), the correlation of the degree of stenosis by the three techniqu es was poor. This discordance is partly due to the insufficiency of ro utine DSA to reliably estimate the degree of stenosis since it deliver s only one anterior-posterior projection plane. The combination of MRA and TCD is a noninvasive regime of high sensitivity to ensure the dia gnosis of MCA stenosis and to estimate the severity of obstruction.