MRI in white matter diseases - Clinico radiological correlation

Objectives: The purpose of this study is to evaluate the role of MRI as an investigative modality in white matter diseases and to document its value in early diagnosis and management. This was done by studying the MR appearances of various white matter diseases encountered in our hospital with special reference to multiple sclerosis and correlating it with the clinical presentation. In addition, the most common diseases among them were identified. Materials and methods: Forty patients with a strong clinical suspicion of demyelinating disorder were evaluated by MRI using 0.5 Tesla (Signa Contour, GE) scanner in a prospective study period of 2 years. Images were obtained in sagittal, axial and coronal planes using SE T1, PD and T2 and FLAIR sequences. Slice thickness of 5mm, FOV of 24 × 24 and 256 × 192 matrix were used. Results: Demyelinating foci were demonstrated with a high degree of accuracy on MR as prolonged T1 and T2 relaxation times, the site of the lesion varying in different disorders. Multiple sclerosis accounted for the majority of cases (37.5%) followed by acute disseminated encephalomyelitis (15%). Other causes like infections, toxic causes, periventricular leukomalacia and leukodystrophies comprised the remainder of the cases. In multiple sclerosis, majority of the patients presented in the third decade of life with a definite female preponderance (M:F - 1:2). The most common symptom and site of involvement were visual impairment (73.3%) and periventricular area (80%) respectively. Conclusion: MRI due to its excellent gray-white matter resolution is very sensitive in detecting subtle demyelination, the sensitivity being still further enhanced by FLAIR sequences. The present study concludes that MRI, in correlation with the clinical signs and symptoms is an ideal modality in early diagnosis of white matter diseases and aids in the early institution of therapy so that the curable conditions among them can be treated.