A case of MELAS: hyperperfused lesions detected by non-invasive perfusion-weighted MR imaging

Area of Science:

• Neurology
• Radiology
• Medical Imaging

Background:

• Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) is a rare mitochondrial disorder.
• Accurate detection and monitoring of MELAS-related brain lesions are crucial for patient management.
• Traditional MRI may not always fully characterize the perfusion dynamics of MELAS lesions.

Observation:

• Perfusion-weighted MRI (PWI) using contrast media was employed to evaluate brain lesions in a MELAS patient.
• FAIR (flow-sensitive alternating inversion recovery), an arterial spin labeling technique, was utilized as a non-contrast PWI method.
• Specific lesions within the brain were identified and characterized based on their perfusion status.

Findings:

• Both contrast-enhanced PWI and FAIR imaging clearly identified MELAS lesions as areas of hyperperfusion.
• One hyperperfused lesion demonstrated a reduction in size following steroid therapy.
• FAIR imaging was capable of detecting this lesion even after its partial resolution.

Implications:

• Perfusion-weighted MRI, particularly FAIR, offers a sensitive method for detecting and monitoring hyperperfused lesions in MELAS.
• These advanced MRI techniques can aid in the diagnosis and assessment of treatment response in MELAS patients.
• The findings highlight the utility of arterial spin labeling in evaluating cerebrovascular changes associated with mitochondrial diseases.