Chemical exchange saturation transfer MR imaging of Parkinson's disease at 3 Tesla.

OBJECTIVES: To demonstrate the feasibility of using chemical exchange saturation transfer (CEST) imaging to detect Parkinson's disease (PD) in patients at 3 Tesla.
METHODS: Twenty-seven PD patients (17 men and 10 women; age range, 54-77 years) and 22 age-matched normal controls (13 men and 9 women; age range, 55-73 years) were examined on a 3-Tesla MRI system. Magnetization transfer spectra with 31 different frequency offsets (-6 to 6 ppm) were acquired at two transverse slices of the head, including the basal ganglia and midbrain. One-way analysis of variance tests was used to compare the differences in CEST imaging signals between PD patients and normal controls.
RESULTS: Total CEST signal between the offsets of 0 and 4 ppm in the substantia nigra was significantly lower in PD patients than in normal controls (P = 0.006), which could be associated with the loss of dopaminergic neurons. Protein-based CEST imaging signals at the offset of 3.5 ppm in the globus pallidus, putamen and caudate were significantly increased in PD patients, compared to normal controls (P < 0.001, P = 0.003, P < 0.001, respectively).
CONCLUSIONS: CEST imaging signals could potentially serve as imaging biomarkers to aid in the non-invasive molecular diagnosis of PD. KEY POINTS: • Total CEST signal in substantia nigra decreased in PD patients • Protein-based CEST signals in basal ganglia increased in PD patients • CEST could assist with the non-invasive molecular diagnosis for PD patients.