DW-MRI vs CTP for stroke

Para dokter sebaiknya menggunakan MRI untuk mendiagnosa stroke dibandingkan dengan menggunakan CT Scan, menurut sebuah guideline yang dikeluarkan oleh American Academy of Neurology (Saint Paul, MN, USA; www.aan.com). Guideline ini dikeluarkan pada Juli 2010 kemarin di jurnal Neurology yang dikelola oleh lembaga ini.

"Saat ini CT scan masih menjadi standar pengujian untuk mendiagnosa stroke, namun kami menemukan bahwa hasil scan MRI jauh lebih baik dalam mendeteksi kerusakan akibat stroke isemik dibandingkan dengan CT Scan". (Ischemic stroke adalah jenis stroke yang disebabkan oleh tersumbatnya pembuluh darah ke otak). Hal ini diungkapkan oleh ketua tim penyusun guideline Peter Schellinger, M.D., (Johannes Wesling Clinical Center Minden, Germany).

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Diffusion MRI measures molecular water motion in the tissue, revealing where water diffusion is restricted and therefore brain damage has occurred. According to the guideline, diffusion MRI should be considered more useful than a CT scan for diagnosing acute ischemic stroke within 12 hours of an individual’s first stroke symptom. In one large study, among others, that was reviewed for the guideline, stroke was accurately detected 83% of the time by MRI versus 26% of the time by CT.

“Specific types of MRI scans can help reveal how severe some types of stroke are. These scans also may help find lesions early,” Dr. Schellinger said. “This is important because the research suggests finding lesions early may lead to better health outcomes.” Moreover, the guideline found MRI scans more effectively detected lesions from stroke and helped identify the severity of some types of stroke or diagnose other medical conditions with similar symptoms. Dr. Schellinger reported that studies have validated the importance of using MRI in emergency rooms but said reservations still exist surrounding the use of stroke MRI scans in clinical settings. “This guideline gives doctors clear direction in using MRI first, ultimately helping people get an acute stroke diagnosis and treatment faster.

However, one situation in which CT may still be used first is when a person needs an emergency injection of drug therapy [also known as intravenous thrombolytic therapy to break up blood clots, if MRI is not immediately available, to avoid delays in starting this treatment. MRI can be added later if more information is needed. Otherwise, MRI should be used first.”

The American Academy of Neurology, an association of more than 22,000 neurologists and neuro-science professionals, is focused on promoting the highest quality patient-centered neurologic care.
Medical Imaging International (November-December/2010)