Hanqiu Liu PhD, Presenter: Nothing to Disclose

To investigate dynamically the MR imaging appearance of MELAS (mitochondrial myopathy, encephalopathy,lactic acidosis, strokes).

Fifteen patients whose diagnosis of MELAS had been pathologically and clinically confirmed were selected . All the patients (male, 11 cases, female, 4 cases; mean age, 22 year old; range, 15–40 year old) received follow-up of MRI. We reviewed all the MR imaging obtained at different time of episode (the course of disease was from 3 months to 5.5 years ,mean time 1.7 years).All the patients were studied with conventional MR Imaging (T1WI,T2WI, FLAIR )and DWI，five patients underwent multiple volume proton MR spectroscopy.

The original examination: Lesions were found in simple lobe 7 cases, in multiple lobes but unilateral hemisphere 6 cases, in multiple lobes and bilateral hemispheres 2 cases.The last examination: Lesions were found in multiple lobes but unilateral hemisphere 7 cases , in multiple lobes and bilateral hemisphere 8 cases. All patients showed gray matter hyperintensity in T2WI,FLAIR and DWI on the phase of episode, the extent and quantity of the strokelike lesions were increased as more often episodes ,and proton MR spectroscopy showed presence of lactate in all the five cases,and a significant choline reduction and N-acetylaspartate reduction were found in areas that appeared abnormal on MR images. On the stationary phase, all the lesions found in simple lobe were disappeared, and the extent and quantity of the lesions in multiple lobes were decreased evidently,but brain atrophy got worse.

MR imaging is a valuable investigational tool for showing dynamic changes of MELAS lesions , and the fluctuating lesions on MRI is not only useful but also characteristic to define the diagnosis and phase of MELAS.

MR imaging is a valuable investigational tool for showing dynamic changes of MELAS lesions.

Liu, H, Dynamic MR Imaging Appearance of MELAS.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5013349.html