Black-blood Luminal Angiography From High Resolution Magnetic Resonance In The Diagnosis Of Atherosclerotic Stenosis Of The Middle Cerebral Artery

0bjective To compared the diagnostic performance of black-blood luminal angiography derived from high-resolution magnetic resonance vessel wall imaging(BBLA)with source images of high-resolution magnetic resonance vessel wall imaging(HRVWI)and time of flight magnetic resonance angiograhy(TOF-MRA)in detecting middle cerebral artery(MCA)stenosis?Methods Sixty-six patients with suspected MCA atherosclerosis examined TOF-MRA,high resolution vessel wall imaging,and CTA.Black-blood luminal angiography was created from source images of HRVWI using minimum intensity projection.The stenosis degree and length of MCA in 66 patients were measured on HRVWI,TOF-MRA,BBLA and CTA,respectively.The sensitivity and specificity of the three methods in the diagnosis of MCA stenosis in different stenosis grades were calculated using CTA as the reference standard.In addition,the kappa values of the three methods were calculated by consistency test.The rank sum test of paired samples was used to evaluate whether there were differences in the measurement of stenosis length by HRVWI,TOF-MRA,BBLA and CTA.Results There was no significant difference in the sensitivity and specificity of BBLA and HRVWI in the diagnosis of moderate and severe MCA stenosis(P >0.05).Compared with TOF-MRA,BBLA showed significantly higher sensitivity for the detection of moderate and severe stenosis(96.2% versus 73.1%,90.0% versus 60.0%P =0.031)and higher specificity for the detection of occlusion(98.7% versus 89.3%,P=0.016).The Kappa values of BBLA,HRVWI and TOF-MRA in diagnosing MCA stenosis were respectively 0.895,0.947 and 0.643.The measurement of stenosis lengthbetween BBLA and CTA(P =0.834)and between TOF-MRA and CTA(P =0.162)was not significantly different.However,there was a significant difference between HRVWI and CTA(P=0.000)and between HRVWI and BBLA(P=0.000).Conclusion BBLA is comparable with CTA in the evaluation of stenosis degree and the length of the MCA.Black-blood luminal angiography is better than TOF-MRA in detecting severe stenosis and occlusion of the MCA.Compared with source images of vessel wall imaging,it is more accurate in evaluating stenosis length;therefore,it could be implemented as an adjunct to HRVWI and TOF-MRA.