title: Crossed cerebellar diaschisis: a positron emission tomography study with L-[methyl-11C]methionine and 2-deoxy-2-[18F]fluoro-D-glucose.
abstract: OBJECTIVE
  Crossed cerebellar diaschisis (CCD) is defined as a depression of blood flow and oxidative metabolism of glucose in the cerebellum contralateral to a supratentorial brain lesion, as detected with positron emission tomography (PET) and single photon emission computed tomography. We examined whether L-[methyl-11C]methionine (MET) uptake is affected in CCD.
  
  
  METHODS
  In 12 patients with a unilateral supratentorial brain tumor, we evaluated the uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) and MET in the cerebellar hemispheres by means of PET. Asymmetry index (AI) was defined as a difference in the average count between the ipsilateral and contralateral cerebellar hemispheres divided by the average count in both cerebellar hemispheres. Patients with AI of FDG PET more than 0.1 and those with AI equal to 0.1 or less than 0.1 were classified as CCD-positive and CCD-negative, respectively.
  
  
  RESULTS
  Six patients were CCD-positive and others were CCD-negative in the FDG PET study. Between CCD-positive and CCD-negative patients, mean AI of MET was not significantly different (0.017 +/- 0.023 and 0.014 +/- 0.039, respectively).
  
  
  CONCLUSIONS
  Different from glucose metabolism, cerebellar MET uptake was not affected in CCD. The present study may indicate that cerebellar MET uptake is independent of suppression of cerebellar neuronal activity.
authors.affiliation: Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Katsufumi
authors.initials: K
authors.lastname: Kajimoto
authors.forename: Naohiko
authors.initials: N
authors.lastname: Oku
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kimura
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.forename: Makiko Rai
authors.initials: MR
authors.lastname: Tanaka
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Kanai
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kitagawa
authors.forename: Motohiko
authors.initials: M
authors.lastname: Maruno
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yoshimine
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hori
authors.forename: Jun
authors.initials: J
authors.lastname: Hatazawa
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D002526:Cerebellar Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002531:Cerebellum / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008715:Methionine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D008715:Methionine; C038344:methionine methyl ester