title: Use of 201Thallium brain SPECT, image registration, and semi-quantitative analysis in the follow-up of brain tumors.
abstract: OBJECTIVE
  To assess the use of 201Thallium SPECT and of Thallium (Tl) uptake indices in the detection and follow-up of cerebral tumors.
  
  
  METHODS
  Two-hundred eighty 201Tl, 135 99mTc-HMPAO scintigraphies and 280 MRI studies were acquired in 135 patients with cerebral tumors. Three types of Tl uptake indices were calculated by establishing the ratio of the lesion activity to an homologous ROI (I1), the contralateral hemisphere (I2), and the contralateral scalp (I3). Intermodal coregistration between Tl-SPECT and MRI when used, was performed using Pietrzyk visual interactive method.
  
  
  RESULTS
  Tl uptake indices showed mean values of 2.0 +/- 0.5 (I1); 1.77 +/- 0.57 (I2) and 1.11 +/- 0.40 (I3) in positive scans, and of 1.05 +/- 0.22 (I1), 0.88 +/- 0.22 (I2) and 0.50 +/- 0.15 (I3) in negative scans, respectively. A linear combination of the two less correlated indices lead to a more powerful discrimination between positive and negative studies. Longitudinal follow-up studies in the same patients showed good concordance between the index values and the course of the disease.
  
  
  CONCLUSIONS
  The use of Tl uptake indices improves the accuracy of Tl-SPECT in the follow-up of brain tumors.
authors.affiliation: Department of Medical Biophysics and Nuclear Medicine, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Rubinstein
authors.forename: H
authors.initials: H
authors.lastname: Karger
authors.forename: U
authors.initials: U
authors.lastname: Pietrzyk
authors.forename: T
authors.initials: T
authors.lastname: Siegal
authors.forename: J M
authors.initials: JM
authors.lastname: Gomori
authors.forename: R
authors.initials: R
authors.lastname: Chisin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000601:surgery; D015609:Organotechnetium Compounds; D010091:Oximes; D012086:Reoperation; D019690:Technetium Tc 99m Exametazime; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D013794:Thallium Radioisotopes; D019690:Technetium Tc 99m Exametazime