Role of Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy in Evaluation of Different Types of Dementia

Aims: The aim of this work is to study the role of magnetic resonance imaging and magnetic resonance spectroscopy in evaluation of dementia patients.

Patients and Methods: This study conducted on fifty patients referred to radio diagnosis and medical imaging department from Neuropsychiatry department at Tanta University Hospital with clinical diagnosis of different types of dementia.

Results: The grade of medial temporal lobe atrophy was higher in AD than in the other two types of dementia. Vascular lesions that fulfill these criteria were present in all patients diagnosed as VaD and their Fazekas score was 3, while patients diagnosed as AD and PDD didn’t have vascular lesions that fulfill NINDS-AIREN criteria and Fazekas scoring of these patients did not exceed 2. Decreased NAA/Cr ratio in the posterior cingulate gyrus was less valuable in diagnosing AD when compared with elevated mI/Cr. Decreased NAA/Cr ratio in the centrum semiovale, Decreased NAA/Cr ratio in the occipital lobe.

Conclusion: MRS is complementary to MRI revealing variable underlying metabolic abnormalities in different dementia subtypes even in cases with apparently normal conventional MRI series. Elevated mI/Cr ratio in the posterior cingulate gyrus is useful indicator when assessing Alzheimer’s dementia and also differentiating it from Vascular dementia and Parkinson’s disease dementia. Decrease in NAA/Cr ratio in the centrum semiovale is useful indicator when assessing suspected vascular dementia. Decrease in NAA/Cr ratio in the occipital lobe is useful indicator when assessing suspected Parkinson’s disease dementia.