Michael Oliver Fluess, Presenter: Nothing to Disclose

Hans Joerg Wittsack PhD, Abstract Co-Author: Nothing to Disclose

Mathias Georg Ludwig Cohnen MD, Abstract Co-Author: Nothing to Disclose

Christian Luckhaus MD, Abstract Co-Author: Nothing to Disclose

Reza Khalili, Abstract Co-Author: Nothing to Disclose

Ulrich Moedder MD, Abstract Co-Author: Nothing to Disclose

To analyze quantitatively regional cerebral blood flow (rCBF) and metabolic changes in patients with Mild Cognitive Impairment (MCI) and Alzheimer´s Disease (AD).

6 patients with AD and 9 patients with MCI as well as 4 age-matched control subjects underwent single voxel MR-Spectroscopy (MRS) and perfusion weighted imaging (PWI) at a clinical 1.5-T scanner. Single voxel MRS was performed using a STEAM sequence (TE=20ms, TR=1.5s) assessing the cingulate cortex. PWI was performed after intravenous injection of 15 ml gadopentetate dimeglumine using a dynamic T2*-weighted single shot EPI-sequence (12 slices, 5 mm, 1.6 s interscan delay) covering mesial temporal (MTC), frontobasal (FBC), temporoparietal (TPC) and anterior cingulate (ACC) cortex. PWI parameter maps were computed indicating rCBF using the arterial input function after normalization to white matter (22 ml/100g/min) and truncation at a threshold value of 100 ml/100g/min. Interactive evaluation was done by a region-of-interest method using anatomic coregistration with 3D high resolution images. Clinical diagnosis was established by MMSE and CDR standard psychometric tests.

rCBF of ACC was not significantly altered in either AD or MCI vs. normal controls. rCBF of FBC (47.51 ± 5.27) and TPC (52.3 ± 3.94) was significantly increased in patients with AD compared to normal controls (FBC: 41.34 ± 0.88; TPC: 42.31 ± 5.39) and patients with MCI (FBC: 37.96 ± 5.05; TPC: 44.3 ± 4.92) respectively (p<0.05). NAA/CR ratio was 1.33 ± 0.13 in AD and 1.36 ± 0.16 in MCI vs. 1.42 ± 0.1 in NP, changes were not significant. rCBF in MTC was 36.64 ± 8.53 in AD, 31.84 ± 7.55 in MCI, and 39.87 ± 7.25 in NP, respectively.

Preliminary results indicate an increase of rCBF in cortical areas that resemble the expected spatial pattern of neuronal loss in AD patients. This pattern may reflect initial processes of preclinical disease. By contrast, our data show a tendency of perfusion decrease in mesial temporal areas, being the primary site of neurofibrillary tangle formation in AD patients. MRS showed a tendency of NAA signal intensity reduction of anterior cingulate cortex both in AD and MCI reflecting neuronal loss in limbic structures.

Fluess, M, Wittsack, H, Cohnen, M, Luckhaus, C, Khalili, R, Moedder, U, Changes of Neuronal Integrity and Perfusion of the Limbic System in Patients with Mild Cognitive Impairment and Alzheimer's Disease.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4409487.html