Prediction of Hemorrhagic Transformation after Acute Ischemic Stroke Using Hyperintense MCA Sign

The hyperintense appearance of the middle cerebral artery (HMCA) sign consists of a thickened MCA stem with a blurred intense signal on contrast enhanced T1-weighted magnetic resonance imaging (T1W MRI). In this article, we define it and determine its incidence, diagnostic value, and reliability by comparison with magnetic resonance angiography and digital subtraction angiography. Non-contrast CT and immediately subsequent MRI were performed on 30 consecutive patients with acute ischemic stroke within 6 hours after symptom onset. Ml patients underwent at least one follow-up MRI or non-contrast CT within 2-7 days. Initial studies were analyzed for HMCA sign on post-Gd T1WI. Vascular findings on both MRI and CT were compared with findings at MRA and DSA. Eleven patients were developed subsequent HT at follow-up studies. The HMCA sign on MRI was found in 6 hemorrhagic patients (P=0.00), and all of them had M1 occlusion on angiography. None of the patients in nonhemorrhagic group had HMCA sign on MRI. It is concluded that HMCA sign on post-Gd T1WI is highly specific and moderately sensitive indicator of acute thrombus with M1 MCA segment, as validated by angiography. Additionally, HMCA sign may be a useful marker of subsequent HT in acute ischemic stroke