Proton Chemical Shift Imaging in Pick Complex

Abstract

BACKGROUND AND PURPOSE: Pick complex (PC) is the name given to a group of diseases comprising Pick disease and its variations, all of which have a large degree of pathologic and clinical overlap. Because of this overlap, the observation of neuropathologic changes in vivo is difficult, although these changes play important roles in the criteria used for classification. The purpose of this study was to evaluate changes in brain metabolism in PC with proton chemical shift imaging (¹H-CSI).

METHODS: Nine patients with PC (three each with frontotemporal dementia, corticobasal degeneration [CBD], and primary progressive aphasia [PPA]) and five healthy subjects underwent ¹H-CSI. Volumes of interest were selected at the level of the basal ganglia by using a spin-echo sequence (TR/TE, 2000/13). Peak areas and ratios of N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) were calculated in voxels in the basal ganglia and perisylvian regions.

RESULTS: Reduced NAA/Cho ratios were observed in the right basal ganglia of the patients with PC. In patients with CBD or PPA, low NAA/Cr values were detected in the right perisylvian region.

CONCLUSION: In PC, ¹H-CSI decreased NAA values in a wide area. Significantly reduced NAA levels in the right hemisphere in patients with PC suggests a neurodegenerative change and may reflect cases in which the right hemisphere is dominantly affected, compared with the left hemisphere. ¹H-CSI provided information that could not be obtained with other imaging techniques. Thus, ¹H-CSI may provide useful information for understanding the pathologic process underlying PC.