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Early diagnosis of hemorrhagic transformation: diffusion/perfusion-weighted MRI versus CT scan
N Nighoghossian1, M Hermier, Y Berthezène
1Cerebrovascular Disease and Ataxia Research Center, Lyon, France.
Unlabelled:
Standard magnetic resonance imaging (MRI) techniques failed to image adequately acute hemorrhagic transformation (HT). Therefore, computed tomography (CT) is still needed to exclude intracerebral hemorrhage. New MRI techniques such as diffusion- and perfusion-weighted imaging (DWI and PWI) may improve the early detection of HT. The utility of this approach requires a direct comparison of the sensitivity of CT with these MRI techniques.
Methods:
Nine patients experienced an acute carotid artery territory ischemic stroke diagnosed on a first CT performed 3.8 +/- 2 h after the onset of stroke. They 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 (EPI) sequence; (2) time of flight MR angiography (TOF MRA); (3) PWI with an axial T(2)*-weighted gradient echo EPI sequence using 20 ml 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 pattern 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.
Insights
New magnetic resonance imaging (MRI) techniques show promise for detecting hemorrhagic transformation (HT) in acute ischemic stroke earlier than standard computed tomography (CT). This could lead to improved stroke management.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Standard magnetic resonance imaging (MRI) is insufficient for detecting acute hemorrhagic transformation (HT) in ischemic stroke.
- Computed tomography (CT) is currently necessary to rule out intracerebral hemorrhage.
- Advanced MRI techniques, including diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI), offer potential for earlier HT detection.
Purpose of the Study:
- To directly compare the sensitivity of CT with novel MRI techniques for detecting acute hemorrhagic transformation (HT).
- To evaluate the utility of diffusion- and perfusion-weighted imaging (DWI/PWI) in the early diagnosis of HT.
Main Methods:
- Nine patients with acute ischemic stroke underwent serial CT scans and a comprehensive MRI protocol.
- The MRI protocol included diffusion-weighted imaging (DWI), time-of-flight MR angiography (TOF MRA), and perfusion-weighted imaging (PWI).
- Hemorrhagic transformation (HT) on DWI was identified as a signal loss within the ischemic area; follow-up CT was performed on day 7.
Main Results:
- MRI detected patterns suggestive of HT in 6 out of 9 patients, whereas CT identified HT in only 1 patient.
- In 5 patients with MRI-detected HT, CT scans did not show obvious signs of bleeding.
- Day 7 CT confirmed HT in all patients initially suspected of bleeding based on DWI criteria.
Conclusions:
- Novel MRI techniques, particularly DWI, show potential for earlier and more sensitive detection of hemorrhagic transformation (HT) in acute ischemic stroke.
- Early detection of HT using MRI may significantly improve the clinical management of stroke patients.