Early diagnosis of hemorrhagic transformation: Diffusion/perfusion-weighted MRI versus CT scan

Standard magnetic resonance imaging (MRI) techniques failed to image adequa tely acute hemorrhagic transformation (HT), Therefore, computed tomography (CT) is still needed to exclude intracerebral hemorrhage. New MRI technique s such as diffusion- and perfusion-weighted imaging (DWI and PWI) may impro ve the early detection of HT. The utility of this approach requires a direc t comparison of the sensitivity of CT with these MRI techniques. Methods: N ine patients experienced an acute carotid artery territory ischemic stroke diagnosed on a first CT performed 3.8 +/- 2h after the onset of stroke. The y underwent a second CT 12 +/- 4 h after the onset of stroke, followed 35 /- 10 min later by an MRI protocol including: (1) an axial isotropic DWI SE echo-planar imaging IEP)) sequence; (2) time of flight MR angiography (TOF MRA); (3) PWI with an axial T-2*-weighted gradient echo EPl sequence using 20 mi gadolinium contrast agent (Gd-DTPA); HT was characterized on DWI SE EPI as a heterogeneous area of signal loss within the ischemic area; (4) at day 7, CT was also performed in all patients who had an early suspicion of bleeding according to MRI. Results: An HT was detected exclusively with CT in 1 out of 9 patients, while an MRI pattern of HT was found in 6 out of 9 patients. In 5 of these 6 patients, the CT scan did not show an obvious pa ttern of HT. Day 7 CT confirmed HT in all patients who had early suspicion of bleeding according to DWI criteria. Conclusion: This study suggests that new MRI techniques may allow an early detection of HT, thus improving the management of stroke. Copyright (C) 2001 S. Karger AG, Basel.