Multimodal Imaging in Diagnosis of Alzheimer's Disease and Amnestic Mild Cognitive Impairment: Value of Magnetic Resonance Spectroscopy, Perfusion, and Diffusion Tensor Imaging of the Posterior Cingulate Region

Article type: Research Article

Authors: Zimny, Anna^{a; *} | Szewczyk, Pawel^a | Trypka, Elzbieta^b | Wojtynska, Renata^b | Noga, Leszek^c | Leszek, Jerzy^b | Sasiadek, Marek^a

Affiliations: [a] Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland | [b] Department of Psychiatry, Wroclaw Medical University, Wroclaw, Poland | [c] Department of Pathophysiology, Wroclaw Medical University, Wroclaw, Poland

Correspondence: [*] Correspondence to: Anna Zimny, Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, ul. Borowska 213, 50 556 Wroclaw, Poland. Tel.: +0048 (71) 733 1660; E-mail: [email protected].

Abstract: The purpose of this study was to assess metabolic, perfusion, and microstructural changes within the posterior cingulate area in patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI) using advanced MR techniques such as: spectroscopy (MRS), perfusion weighted imaging (PWI), and diffusion tensor imaging (DTI). Thirty patients with AD (mean age 71.5 y, MMSE 18), 23 with aMCI (mean age 66 y, MMSE 27.4), and 15 age-matched normal controls (mean age 69 y, MMSE 29.5) underwent conventional MRI followed by MRS, PWI, and DTI on 1.5 Tesla MR unit. Several metabolite ratios (N-acetylaspartate [NAA]/creatine [Cr], choline [Ch]/Cr, myoinositol [mI]/Cr, mI/NAA, mI/Cho) as well as parameters of cerebral blood volume relative to cerebellum and fractional anisotropy were obtained in the posterior cingulate region. The above parameters were correlated with the results of neuropsychological tests. AD patients showed significant abnormalities in all evaluated parameters while subjects with aMCI showed only perfusion and diffusion changes in the posterior cingulate area. Only PWI and DTI measurements revealed significant differences among the three evaluated subject groups. DTI, PWI, and MRS results showed significant correlations with neuropsychological tests. DTI changes correlated with both PWI and MRS abnormalities. Of neuroimaging methods, DTI revealed the highest accuracy in diagnosis of AD and aMCI (0.95, 0.79) followed by PWI (0.87, 0.67) and MRS (0.82, 0.47), respectively. In conclusion, AD is a complex pathology regarding both grey and white matter. DTI seems to be the most useful imaging modality to distinguish between AD, aMCI, and control group, followed by PWI and MRS.

Keywords: Alzheimer's disease, amnestic mild cognitive impairment, diffusion tensor imaging, magnetic resonance spectroscopy, perfusion weighted MR imaging, posterior cingulate area

DOI: 10.3233/JAD-2011-110254

Journal: Journal of Alzheimer's Disease, vol. 27, no. 3, pp. 591-601, 2011