title: Clinical usefulness of attenuation and scatter correction in Tl-201 SPECT studies using coronary angiography as a reference.
abstract: BACKGROUND
  The aim of this investigation was to evaluate the clinical usefulness of both attenuation and scatter correction in 201Tl SPECT studies.
  
  
  METHODS
  We studied 102 patients (76 males, 26 females, mean age 54 years) who underwent coronary angiography prior to or after a scintigraphic examination. A 201Tl one-day protocol was used. Simultaneous transmission-emission images were obtained by a gamma-camera equipped with an attenuation and scatter correction system based on two moving collimated 153Gd rod sources. Stress and delay reconstructed images, uncorrected for attenuation and scatter, were diagnosed. One month later, stress and delay reconstructed images corrected for attenuation and scatter were diagnosed by the same readers. The results were compared using the coronary angiography findings as reference. A stenosis 50% or larger was considered significant.
  
  
  RESULTS
  Attenuation and scatter corrected images demonstrated a significant increase in specificity for findings in the right coronary artery territory, i.e. 89% vs. 41% for uncorrected images (p < 0.05), with a non-significant loss in sensitivity from 96% to 89%. When we split the population on a gender basis, statistically significant differences in specificity between corrected and non-corrected images were observed in the left anterior descending territory for the females (100% vs. 42%) and in the right coronary artery territory for males (87% vs. 26%).
  
  
  CONCLUSIONS
  Attenuation and scatter correction in 201Tl SPECT studies may significantly decrease false positive lesions in the inferior wall as well as in the anterior in females.
authors: Department of Nuclear Medicine, University Hospital of Heraklion, Greece. jtkoutsik@yahoo.gr
authors: Antigoni
authors: A
authors: Velidaki
authors: Kostas
authors: K
authors: Perisinakis
authors: Sophia
authors: S
authors: Koukouraki
authors: John
authors: J
authors: Koutsikos
authors: Panos
authors: P
authors: Vardas
authors: Nicolaos
authors: N
authors: Karkavitsas
mesh_terms: D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D012372:ROC Curve; D012016:Reference Values; D012588:Scintillation Counting / Q000379:methods*; D012680:Sensitivity and Specificity; D012737:Sex Factors; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D013794:Thallium Radioisotopes