Depression in Parkinson's disease. Diffusion tensor imaging study.

OBJECTIVES: The pathophysiology of depression and anxiety in Parkinson's disease remains obscure. We aimed to compare the fractional anisotropy (FA) values of Parkinson's disease (PD) patients with and without depression to investigate the nature of depression in PD. METHODS: Twenty-eight patients were divided into two groups: those with depression and those without. Diagnosis of depression was made using the DSM-IV criteria. Patients in the two groups were matched for Hoehn Yahr stage. RESULTS: There were significant reductions in FA values in the bilateral frontal ROIs possibly representing anterior cingulate bundles. CONCLUSIONS: The anterior cingulate bundles play an important role in depression in PD, and some aspects of depression in PD have pathological processes in common with de novo depression.

Disruptions of the fornix fiber in Parkinsonian patients with excessive daytime sleepiness.

BACKGROUND: Although excessive daytime sleepiness (EDS) in Parkinson's disease (PD) has received a great deal of attention, the underlying pathological mechanism of its development and the relative contributions of brain function to this process are poorly understood. OBJECTIVE: To compare the fractional anisotropy (FA) values of PD patients with EDS and those without EDS, and to investigate the mechanism of EDS in this disease. METHODS: Eleven patients with PD with EDS, 26 patients with PD without EDS and 10 controls participated in this study. Patients with an ESS (Epworth Sleepiness Scale) score >or=10 were defined as having EDS. The FA values of 5 regions of interest (ROI) including the fornix were compared between the three groups. RESULTS: There were significant reductions in FA values of the fornix fiber in patients with EDS. ESS scores had significant correlation with FA values of the fornix. CONCLUSIONS: Our study is the first to find the fornix fiber degeneration in PD patients with EDS. These results indicate that fornix dysfunction may have some correlations with EDS in PD.

Two-pass dual-energy CT imaging for simultaneous detection, characterization, and volume measurement of urinary stones with excretory-phase CT urography alone: a phantom study.

PURPOSE: To evaluate if two-pass dual-energy CT imaging--i.e., simultaneous three-material and two-material decomposition analysis--can depict and characterize urinary stones in various concentrations of iodine solution in vitro. MATERIALS AND METHODS: Twelve urinary stones were scanned with a dual-source CT scanner. First, each stone (in a saline-filled tube) underwent single- and dual-energy mode CT scans in order to measure the volume of the stone. Each stone was then placed in various concentrations of contrast medium and scanned in dual-energy mode to calculate its volume via three-material decomposition analysis. Two-pass dual-energy CT imaging analysis software for the Matlab environment, which was developed specifically to process simultaneous three-material and two-material decomposition, was applied to characterize and calculate the volume of each stone. RESULTS: Although the virtual non-contrast images from three-material decomposition analysis clearly visualized all of the stones in contrast medium with up to 80 mgI/mL, the volumes of the uric acid stones were overestimated. Two-pass dual-energy CT imaging was able to depict and characterize non-uric-acid stones in diluted contrast medium with up to 80 mgI/mL, whereas uric acid stones were correctly evaluated in diluted contrast medium with 40 mgI/mL or less. CONCLUSIONS: Two-pass dual-energy CT imaging is able to depict and characterize urinary stones in contrast medium.