Amide proton transfer MR imaging at 3. 0 T of the basal ganglia in Parkinson's disease

Objective: To explore the feasibility of amide proton transfer (APT) MR imaging for the detection of basal ganglia abnormalities in patients with Parkinson' s disease (PD). Methods: Twenty-seven patients with PD and twenty-three age-matched normal control subjects underwent cerebral APT and structural MR imaging. The magnetic resonance ratio asymmetry (MTRasym) values at 3.5 ppm of bilateral globus pallidus, putamen and caudate were measured on APT images. MTRasym (3.5 ppm) values of cerebral structures between PD patients and control subjects were compared with independent-samples t test. Paired-samples t test was used to compare the difference of MTRasym (3.5 ppm) between the side of onset and contralateral side in patients with PD. The difference of MTRasym (3.5 ppm) among normal controls, early-stage PD, and advanced-stage PD patients was assessed with one-way analysis of variance. Results: Compared to normal controls, MTRasym(3.5 ppm) values of globus pallidus, putamen and caudate were significantly increased in PD patients ((0.89 ± 0.12)% vs (0.57 ± 0.16)%, (1.05 ± 0.11)% vs (0.82 ± 0.15)%, (1.15 ± 0.13)% vs (0.78 ± 0.19)%; t = 3.311, 2.562, 3.277 respectively, all P values <0.05). Significant differences in MTRasym (3.5 ppm) values of these cerebral structures were observed among normal controls, early-stage PD and advanced-stage PD patients. And MTRasym (3.5 ppm) values in globus pallidus, putamen and caudate were significantly higher in early-stage PD patients than normal controls. In PD patients, even not statistically significant, MTRasym (3.5 ppm) values of sides of onset were slightly lower than contralateral sides. Conclusions: APT MR imaging can sensitively identify the difference of MTRasym (3.5 ppm) in the basal ganglia between PD patients and normal controls. APT might be a useful tool to evaluate abnormal metabolite in basal ganglia of PD patients.