Putaminal abnormality on 3-T magnetic resonance imaging in early parkinsonism-predominant multiple system atrophy

Abstract

To evaluate the diagnostic value of putaminal abnormality on 3-T magnetic resonance imaging (MRI) for differentiating early parkinsonism-predominant multiple system atrophy (MSA-p) from Parkinson disease (PD) based on long-term clinical follow-up data. Totals of 23 clinical MSA-p (6 possible and 17 suspicious) and 50 PD patients were included. Subjects submitted to 3-T MRI at baseline and were followed up to substantiate the initial diagnosis. MRI findings were compared between MSA-p and PD patients based on the final diagnosis. Putaminal abnormalities were recorded as presence of atrophy, signal hypointensity, and abnormal disruption of the hyperintense lateral rim of the putamen. The sum scores for putaminal abnormality were calculated from the presence of each item. During the follow-up over 3 years, the diagnosis of MSA-p was supported in 17 patients (14 probable and 3 possible) and the diagnosis of PD was stable in all 50 patients. Putaminal abnormalities were more frequent in MSA-p (n = 17) than in PD (n = 50). A sum score of >1 on 3-T MRI had sensitivity, specificity, and positive- and negative-predictive values of 70.6, 93, 77.4, and 90.3%, respectively, for differentiating MSA-p from PD. Fourteen of the initial 23 clinical MSA-p patients had a sum score of >1, and in all but two, the diagnosis became supported during the follow-up, whereas the diagnosis of five of the nine patients with a sum score of ≤1 remained uncertain. Putaminal abnormality on 3-T MRI can be a specific diagnostic marker for early stage MSA-p.

Differentiation of Parkinsonism-Predominant Multiple System Atrophy from Idiopathic Parkinson Disease Using 3T Susceptibility-Weighted MR Imaging, Focusing on Putaminal Change and Lesion Asymmetry

“…The sensitivity of this study was similar or slightly lower than those previously published for studies that used conventional fast spin-echo-based 3T MR imaging findings. 17,18 The sensitivity of our study was comparable with those of published studies that used T2*-weighted imaging. 19,20 By ROC curve analysis of the quantitative phase-shift values, sensitivity was increased to 77.8%, while specificity was slightly decreased (76.0%).…”

Neuromelanin Magnetic Resonance Imaging in Parkinson's Disease and Multiple System Atrophy

“…Using T2WI, we evaluated the neuroradiological change of putaminal abnormality, increased the T2 signal in the middle cerebellar peduncles (MCP) and the ‘hot cross bun' sign on MSA patients. Putaminal atrophy on T2WI was evaluated using the following definition: grade 0 = no visualization of putaminal atrophy, grade 1 = visualization of slight putaminal atrophy, grade 2 = definite putaminal atrophy without hyperintense putaminal rim, and grade 3 = definite putaminal atrophy with hyperintense putaminal rim [19]. An increased T2 signal in the MCP was assessed using the following definition: grade 0 = no visualization of increased T2 signal in the MCP, grade 1 = slightly increased T2 signal in the MCP without MCP atrophy, grade 2 = definite increased T2 signal in the MCP with or without MCP atrophy, and grade 3 = definite increased T2 signal in the MCP with severe MCP atrophy [20,21].…”

Hyperintense putaminal rim at 1.5 T: prevalence in normal subjects and distinguishing features from multiple system atrophy

“…Based on their observations, Fujii et al considered HPR in normal subjects as a “pseudosign” — a perceived hyperintensity due to hypointensity of the remainder of the putamen induced by age-related iron deposition. They also commented that HPR was clearly visible at 3 T, but not at 1.5 T, due to pronounced susceptibility effects at 3 T. In light of the findings of these reports, a few recent studies performed using 3 T have taken into account the possibility of observing HPR in normal subjects [11,12]. …”