Investigation of Apparent Diffusion Coefficient from Ultra-high b-Values in Parkinson's Disease.
OBJECTIVE
To assess brain damage in Parkinson's disease (PD) based on apparent diffusion coefficient (ADC) data obtained from ultra-high b-values.


METHODS
Eighteen PD patients and 18 controls received diffusion-weighted imaging (DWI) with standard b-values (0, 1,000 s/mm(2)) and 15 b-values (0-5,000 s/mm(2)). Standard ADC (ADCst) maps were calculated from standard b-values, while maps of pure diffusion coefficients (D), pseudo-diffusion coefficients (D(*)), and ultra-high ADCs (ADCuh) were calculated from the 15 b-values using a tri-component model. In this model, D and D(*) values were quantified with a bi-exponential equation using b-values less than 2,000 s/mm(2), while ADCuh was quantified by fitting the signals at ultra-high b-values (2,000-5,000 s/mm(2)) to the mono-exponential equation. ADCst, ADCuh, D, and D(*) of the globus pallidus (GP), putamen (P), and substantia nigra (SN) were compared between PD patients and normal control subjects.


RESULTS
ADCuh of the GP, P, and SN was significantly lower in PD patients than those in control subjects (P < 0.001), while ADCst, D, and D(*) of the GP, P and SN were not different between the two groups (P > 0.05).


CONCLUSIONS
ADCuh may be a useful measurement for evaluating brain damage in PD patients.


CONCLUSIONS
• DWI with ultra-high b-values may provide new insight into Parkinson's disease pathology • ADC calculated using ultra-high b-values is different between PD and controls • ADC uh may be associated with water transportation by aquaporins.
Department of Medical Imaging Center, the First Affiliated Hospital, Jinan University, Huangpu West Road, Guangzhou, China.
Ling
L
Xueying
Zhang
Z
Zhongping
Zhao
Z
Zhoushe
Guo
G
Li
Tang
T
Yongjin
Shi
S
Changzheng
Zhou
Z
Zhifeng
Chen
C
Peihao
Xu
X
Hao
Huang
H
Li
D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology*; D011446:Prospective Studies