Masahiro Uemura1, Kenshi Terajima1,2,3, Yuji Suzuki2, Masaki Watanabe2, Yasuhisa Akaiwa1, Shinichi Katada1, Kouichirou Okamoto4, Masatoyo Nishizawa1, Hironaka Igarashi2, Tsutomu Nakada2. 1. Department of Neurology, Brain Research Institute, Niigata University, Niigata, Japan. 2. Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan. 3. Department of Medical Informatics, Uonuma Institute of Community Medicine, Niigata University Medical and Dental Hospital, Niigata University, Niigata, Japan. 4. Department of Neurosurgery, Brain Research Institute, Niigata University, Niigata, Japan.
Abstract
BACKGROUND AND PURPOSE: Presence of an intimal flap is a critical imaging finding in diagnosing intracranial artery dissection (ICAD). Recent reports showed that high-resolution magnetic resonance imaging (MRI) was better at identifying intimal flaps as compared with routine MRI techniques used in clinical settings. However, no current standardized sequence for high-resolution MRI without gadolinium enhancement produces images of satisfactory quality with clinically tolerable scanning times. This study evaluated a nonenhanced high-resolution fast spin echo (HR-FSE) MRI sequence for visualizing intimal flaps in patients with ICAD. SUBJECTS AND METHODS: Three patients with ICAD underwent plain MRI examination using a 2-dimensional T2-weighted FSE imaging sequence optimized for our 3T system (in-plane pixel size, .23 mm × .23 mm; slice thickness 3 mm with no interslice gap), as well as scanning with conventional modalities, including CT angiography, magnetic resonance angiography, and digital subtraction angiography. We assessed whether these imaging methods could visualize an intimal flap and/or double lumen sign in the participants and compared the results between HR-FSE and the other modalities. RESULTS: HR-FSE images clearly showed intimal flaps and double lumen signs in all 3 patients, whereas the conventional modalities identified a double lumen sign in only 2 of the 3 patients. CONCLUSIONS: The present method of optimized HR-FSE imaging with a 3T system improved visualization of intimal flaps and should thus be considered for assessing patients with suspected ICAD that cannot be definitively diagnosed by conventional imaging modalities.
BACKGROUND AND PURPOSE: Presence of an intimal flap is a critical imaging finding in diagnosing intracranial artery dissection (ICAD). Recent reports showed that high-resolution magnetic resonance imaging (MRI) was better at identifying intimal flaps as compared with routine MRI techniques used in clinical settings. However, no current standardized sequence for high-resolution MRI without gadolinium enhancement produces images of satisfactory quality with clinically tolerable scanning times. This study evaluated a nonenhanced high-resolution fast spin echo (HR-FSE) MRI sequence for visualizing intimal flaps in patients with ICAD. SUBJECTS AND METHODS: Three patients with ICAD underwent plain MRI examination using a 2-dimensional T2-weighted FSE imaging sequence optimized for our 3T system (in-plane pixel size, .23 mm × .23 mm; slice thickness 3 mm with no interslice gap), as well as scanning with conventional modalities, including CT angiography, magnetic resonance angiography, and digital subtraction angiography. We assessed whether these imaging methods could visualize an intimal flap and/or double lumen sign in the participants and compared the results between HR-FSE and the other modalities. RESULTS:HR-FSE images clearly showed intimal flaps and double lumen signs in all 3 patients, whereas the conventional modalities identified a double lumen sign in only 2 of the 3 patients. CONCLUSIONS: The present method of optimized HR-FSE imaging with a 3T system improved visualization of intimal flaps and should thus be considered for assessing patients with suspected ICAD that cannot be definitively diagnosed by conventional imaging modalities.