title: Using 'swallow-tail' sign and putaminal hypointensity as biomarkers to distinguish multiple system atrophy from idiopathic Parkinson's disease: A susceptibility-weighted imaging study.
abstract: OBJECTIVE
  To investigate the value of 'swallow-tail' sign and putaminal hypointensity on 3 T susceptibility-weighted imaging (SWI) for distinguishing multiple system atrophy (MSA) from idiopathic Parkinson's disease (IPD).
  
  
  METHODS
  Three groups - 39 MSA patients, 18 IPD patients,and 31 healthy controls (HCs) - were administered a 3 T SWI sequence to evaluate 'swallow-tail' sign and putaminal hypointensity using visual scales from 0 to 2 and 0 to 3 scores, respectively. The diagnostic accuracy of the two signs separately and combined was calculated using a receiver operating characteristic curve, with clinical diagnosis as the gold standard.
  
  
  RESULTS
  The scores of 'swallow-tail' sign were lower in IPD than in MSA or in HCs, as well as for putaminal hypointensity in IPD or HCs than in MSA (p < 0.05). The sensitivity and specificity of 'swallow-tail' sign and putaminal hypointensity were 87.9% and 83.3%, and 35.9% and 100%, respectively, in the respective patient groups. The area under the curve of combined signs was increased from 0.85 ('swallow tail') or 0.68 (putaminal hypointensity) to 0.93.
  
  
  CONCLUSIONS
  The combination of 'swallow-tail' sign and putaminal hypointensity can increase the accuracy of discriminating between MSA and IPD.
  
  
  CONCLUSIONS
  • Differential diagnosis of MSA and IPD is still challenging in clinical practice. • Absence of 'swallow-tail' sign is a valuable biomarker for IPD on SWI. • Putaminal hypointensity is a valuable biomarker for MSA on SWI. • Combined 'swallow- tail' sign and putaminal hypointensity increase diagnostic accuracy.
authors.affiliation: Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, 110001, Liaoning, People's Republic of China.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, 110001, Liaoning, People's Republic of China.
authors.forename: HuaGuang
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, 110001, Liaoning, People's Republic of China.
authors.forename: ChengBo
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, 110001, Liaoning, People's Republic of China. fanguog@sina.com.
authors.forename: GuoGuang
authors.initials: G
authors.lastname: Fan
authors.affiliation: Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, 110001, Liaoning, People's Republic of China. grace_shenyang@163.com.
authors.forename: XiaoGuang
authors.initials: X
authors.lastname: Luo
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001284:Atrophy; D015415:Biomarkers; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D011699:Putamen / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013378:Substantia Nigra / Q000000981:diagnostic imaging*
chemical_list: D015415:Biomarkers
keywords: Idiopathic Parkinson’s disease; Multiple system atrophy; Putaminal hypointensity; Susceptibility-weighted imaging; Swallow tail