Diffusion and Perfusion Characteristics of MELAS (Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-Like Episode) in Thirteen Patients.
- Author:
Ji Hye KIM
1
;
Myung Kwan LIM
;
Tae Yeon JEON
;
Jung Ho RHA
;
Hong EO
;
So Young YOO
;
Chang Hae SHU
Author Information
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords: Mitochondrial encephalopathy; Diffusion weighted imaging; Perfusion MR imaging; Stroke
- MeSH: Adolescent; Adult; Brain/*pathology; Brain Edema/pathology; Child; *Diffusion Magnetic Resonance Imaging; Female; Humans; MELAS Syndrome/*pathology; *Magnetic Resonance Angiography; Male; Middle Aged; Stroke/pathology; Young Adult
- From:Korean Journal of Radiology 2011;12(1):15-24
- CountryRepublic of Korea
- Language:English
- Abstract: OBJECTIVE: We analyzed the diffusion and perfusion characteristics of acute MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episode) lesions in a large series to investigate the controversial changes of the apparent diffusion coefficient (ADC) that were reported in prior studies. MATERIALS AND METHODS: We analyzed 44 newly appearing lesions during 28 stroke-like episodes in 13 patients with MELAS. We performed a visual assessment of the MR images including the ADC and perfusion maps, comparison of the ADC between the normal and abnormal areas, comparison of % ADC between the 44 MELAS lesions and the 30 acute ischemic infarcts. In addition, the patterns of evolution on follow-up MR images were analyzed. RESULTS: Decreased, increased, and normal ADCs were noted in 16 (36%), 16 (36%), and 12 (27%) lesions, respectively. The mean % ADC was 102 +/- 40.9% in the MELAS and 64 +/- 17.8% in the acute vascular infarcts (p < 0.001), while perfusion imaging demonstrated hyper-perfusion in six acute MELAS lesions. On follow-up images, resolution, progression, and tissue loss were noted in 10, 4, and 17 lesions, respectively. CONCLUSION: The cytotoxic edema gradually evolves following an acute stroke-like episode in patients with MELAS, and this may overlap with hyper-perfusion and vasogenic edema. The edematous swelling may be reversible or it may evolve to encephalomalacia, suggesting irreversible damage.
