Differentiation of Parkinsonism-Predominant Multiple System Atrophy from Idiopathic Parkinson Disease Using 3T Susceptibility-Weighted MR Imaging, Focusing on Putaminal Change and Lesion Asymmetry.
OBJECTIVE
Asymmetric presentation of clinical feature in parkinsonism is common, but correlatable radiologic feature is not clearly defined. Our aim was to evaluate 3T susceptibility-weighted imaging findings for differentiating parkinsonism-predominant multiple system atrophy from idiopathic Parkinson disease, focusing on putaminal changes and lesion asymmetry.


METHODS
This retrospective cohort study included 27 patients with parkinsonism-predominant multiple system atrophy and 50 patients with idiopathic Parkinson disease diagnosed clinically. Twenty-seven age-matched subjects without evidence of movement disorders who underwent SWI were included as the control group. A consensus was reached by 2 radiologists who visually assessed SWI for the presence of putaminal atrophy and marked signal hypointensity on each side of the posterolateral putamen. We also quantitatively measured putaminal width and phase-shift values.


RESULTS
The mean disease duration was 4.7 years for the patients with parkinsonism-predominant multiple system atrophy and 7.8 years for the patients with idiopathic Parkinson disease. In the patients with parkinsonism-predominant multiple system atrophy, putaminal atrophy was frequently observed (14/27, 51.9%) and was most commonly found in the unilateral putamen (13/14). Marked signal hypointensity was observed in 12 patients with parkinsonism-predominant multiple system atrophy (44.4%). No patients with idiopathic Parkinson disease or healthy controls showed putaminal atrophy or marked signal hypointensity. Quantitatively measured putaminal width, phase-shift values, and the ratio of mean phase-shift values for the dominant and nondominant sides were significantly different between the parkinsonism-predominant multiple system atrophy group and the idiopathic Parkinson disease and healthy control groups (P < .001).


CONCLUSIONS
3T SWI can visualize putaminal atrophy and marked signal hypointensity in patients with parkinsonism-predominant multiple system atrophy with high specificity. Furthermore, it clearly demonstrates the dominant side of putaminal changes, which correlate with the contralateral symptomatic side of patients.
From the Departments of Radiology (I.H., C.-H.S., K.M.K, S.H.C., T.J.Y., J.-h.K.).
I
http://orcid.org/0000-0002-1291-8973
I
Hwang
From the Departments of Radiology (I.H., C.-H.S., K.M.K, S.H.C., T.J.Y., J.-h.K.) Department of Radiology (C.-H.S.), Seoul National University College of Medicine, Seoul, Korea Institute of Radiation Medicine (C.-H.S.), Seoul National University Medical Research Center, Seoul, Korea. neurorad63@gmail.com.
C-H
http://orcid.org/0000-0003-0039-5746
CH
Sohn
From the Departments of Radiology (I.H., C.-H.S., K.M.K, S.H.C., T.J.Y., J.-h.K.).
K M
http://orcid.org/0000-0001-9643-2008
KM
Kang
Neurology (B.S.J., H.-J.K.), Seoul National University Hospital, Seoul, Korea.
B S
BS
Jeon
Neurology (B.S.J., H.-J.K.), Seoul National University Hospital, Seoul, Korea.
H-J
HJ
Kim
From the Departments of Radiology (I.H., C.-H.S., K.M.K, S.H.C., T.J.Y., J.-h.K.).
S H
http://orcid.org/0000-0002-0412-2270
SH
Choi
From the Departments of Radiology (I.H., C.-H.S., K.M.K, S.H.C., T.J.Y., J.-h.K.).
T J
http://orcid.org/0000-0001-8441-4574
TJ
Yun
From the Departments of Radiology (I.H., C.-H.S., K.M.K, S.H.C., T.J.Y., J.-h.K.).
J-H
http://orcid.org/0000-0002-6349-6950
JH
Kim
D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000150:complications / Q000175:diagnosis*; D010300:Parkinson Disease / Q000175:diagnosis*; D020734:Parkinsonian Disorders / Q000175:diagnosis* / Q000209:etiology; D011699:Putamen / Q000473:pathology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity