Chemical Exchange Saturation Transfer MR Imaging is Superior to Diffusion-Tensor Imaging in the Diagnosis and Severity Evaluation of Parkinson's Disease: A Study on Substantia Nigra and Striatum.

Chunmei Li,Rui Wang,Wen Su,Min Chen,Haibo Chen,Jian Qiao,Guodong Song,Baohui Lou,Xuna Zhao,Shuhua Li,Jinyuan Zhou

doi:10.3389/fnagi.2015.00198

Abstract

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by nigrostriatal cell loss. To date, the diagnosis of PD is still based primarily on the clinical manifestations, which may be typical and obvious only in advanced-stage PD. Thus, it is crucial to find a reliable marker for the diagnosis of PD. We conducted this study to assess the diagnostic efficiency of chemical exchange saturation transfer (CEST) imaging and diffusion-tensor imaging (DTI) in PD at 3 T by evaluating changes on substantia nigra and striatum. Twenty-three PD patients and twenty-three age-matched normal controls were recruited. All patients and controls were imaged on a 3-T MR system, using an eight-channel head coil. CEST imaging was acquired in two transverse slices of the head, including substantia nigra and striatum. The magnetization transfer ratio asymmetry at 3.5 ppm, MTRasym(3.5 ppm), and the total CEST signal intensity between 0 and 4 ppm were calculated. Multi-slice DTI was acquired for all the patients and normal controls. Quantitative analysis was performed on the substantia nigra, globus pallidus, putamen, and caudate. The MTRasym(3.5 ppm) value, the total CEST signal intensity, and fractional anisotropy value of the substantia nigra were all significantly lower in PD patients than in normal controls (P = 0.003, P = 0.004, and P < 0.001, respectively). The MTRasym(3.5 ppm) values of the putamen and the caudate were significantly higher in PD patients than in normal controls (P = 0.010 and P = 0.009, respectively). There were no significant differences for the mean diffusivity in these four regions between PD patients and normal controls. In conclusion, CEST MR imaging provided multiple CEST image contrasts in the substantia nigra and the striatum in PD and may be superior to DTI in the diagnosis of PD.

Highlights

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by nigrostriatal cell loss, resulting in striatal dopamine deficiency (Dauer and Przedborski, 2003)
The value difference between PD patient and normal control can be obviously seen in regions of the substantia nigra in amide proton transfer (APT)-weighted image
The fractional anisotropy (FA) value difference between PD patient and normal control seemed to be unapparent in the substantia nigra though they have group differences

Summary

Introduction

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by nigrostriatal cell loss, resulting in striatal dopamine deficiency (Dauer and Przedborski, 2003). Accurate diagnosis in early stage of PD and early initiation of therapy may provide benefit for the patient (Olanow et al, 2009). To date, the diagnosis of PD is still based primarily on the clinical manifestations, which may be typical and obvious only in advanced-stage PD. Several functional MR imaging have been used to assist in the PD diagnosis, including diffusion-tensor imaging (DTI). DTI has typically been used to detect axon and myelin injury in white matter of PD patients (Cnyrim et al, 2014; Kamagata et al, 2014), while some studies have focused on evaluating the abnormalities in gray matter (Prakash et al, 2012; Zhan et al, 2012; Lenfeldt et al, 2013)

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