title: Usefulness of quantitative susceptibility mapping for the diagnosis of Parkinson disease.
abstract: OBJECTIVE
  Quantitative susceptibility mapping allows overcoming several nonlocal restrictions of susceptibility-weighted and phase imaging and enables quantification of magnetic susceptibility. We compared the diagnostic accuracy of quantitative susceptibility mapping and R2* (1/T2*) mapping to discriminate between patients with Parkinson disease and controls.
  
  
  METHODS
  For 21 patients with Parkinson disease and 21 age- and sex-matched controls, 2 radiologists measured the quantitative susceptibility mapping values and R2* values in 6 brain structures (the thalamus, putamen, caudate nucleus, pallidum, substantia nigra, and red nucleus).
  
  
  RESULTS
  The quantitative susceptibility mapping values and R2* values of the substantia nigra were significantly higher in patients with Parkinson disease (P < .01); measurements in other brain regions did not differ significantly between patients and controls. For the discrimination of patients with Parkinson disease from controls, receiver operating characteristic analysis suggested that the optimal cutoff values for the substantia nigra, based on the Youden Index, were >0.210 for quantitative susceptibility mapping and >28.8 for R2*. The sensitivity, specificity, and accuracy of quantitative susceptibility mapping were 90% (19 of 21), 86% (18 of 21), and 88% (37 of 42), respectively; for R2* mapping, they were 81% (17 of 21), 52% (11 of 21), and 67% (28 of 42). Pair-wise comparisons showed that the areas under the receiver operating characteristic curves were significantly larger for quantitative susceptibility mapping than for R2* mapping (0.91 versus 0.69, P < .05).
  
  
  CONCLUSIONS
  Quantitative susceptibility mapping showed higher diagnostic performance than R2* mapping for the discrimination between patients with Parkinson disease and controls.
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.) kakeda@med.uoeh-u.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Kakeda
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: I
authors.initials: I
authors.lastname: Ueda
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: A
authors.initials: A
authors.lastname: Ogasawara
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: J
authors.initials: J
authors.lastname: Moriya
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: S
authors.initials: S
authors.lastname: Ide
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: K
authors.initials: K
authors.lastname: Futatsuya
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.affiliation: Neurology (K.O., T.U., S.T.), University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Okada
authors.affiliation: Neurology (K.O., T.U., S.T.), University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Uozumi
authors.affiliation: Neurology (K.O., T.U., S.T.), University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tsuji
authors.affiliation: Departments of Biomedical Engineering and Radiology (T.L., Y.W.), Cornell University, New York, New York.
authors.forename: T
authors.initials: T
authors.lastname: Liu
authors.affiliation: Departments of Biomedical Engineering and Radiology (T.L., Y.W.), Cornell University, New York, New York.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.affiliation: From the Departments of Radiology (Y.M., S.K., K.W., I.U., A.O., J.M., S.I., K.F., T.S., Y.K.).
authors.forename: Y
authors.initials: Y
authors.lastname: Korogi
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007501:Iron / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000473:pathology; D012680:Sensitivity and Specificity; D013378:Substantia Nigra / Q000473:pathology
chemical_list: D007501:Iron