title: Diagnostic value of Tl-201 lung uptake is dependent on measurement method.
abstract: BACKGROUND
  Increased lung uptake during exercise thallium 201 single photon emission computed tomography is related to left ventricular dysfunction and extent of coronary artery disease (CAD). We studied the influence of the lung region of interest (ROI), used to quantify Tl-201 lung uptake, on the diagnostic value of the lung-to-heart uptake ratio (LHR) in detecting CAD with Tl-201 myocardial single photon emission computed tomography.
  
  
  RESULTS
  We retrospectively studied 152 consecutive patients referred to our center for stress Tl-201 scanning. Of these, 116 had proven multivessel CAD and 36 had either normal findings on coronary angiogram or a low likelihood (<5%) of CAD. Poststress quantitative analysis was performed from a 4 x 4-pixel ROI over the hottest myocardial region, an 8 x 8-pixel left lung ROI, an 8 x 8-pixel right lung ROI, and a manual ROI encompassing the whole right lung. The LHR was calculated for each lung ROI. Right LHR (R-LHR) provided the best interobserver and intraobserver reproducibility. R-LHR and total R-LHR values were significantly higher in patients with CAD. Only history of myocardial infarction significantly influenced the R-LHR measurement.
  
  
  CONCLUSIONS
  The methodology of LHR measurement significantly influences the clinical contribution of Tl-201 lung uptake evaluation. Optimal reproducibility and diagnostic accuracy are provided by a right lung ROI.
authors.affiliation: GIE de Médecine Nucléaire, CHU de Rouen et Centre Henri Becquerel, and Service de Cardiologie, CHU de Rouen, Hôpital Charles Nicolle, Rouen, France.
authors.forename: A
authors.initials: A
authors.lastname: Hitzel
authors.forename: A
authors.initials: A
authors.lastname: Manrique
authors.forename: A
authors.initials: A
authors.lastname: Cribier
authors.forename: P
authors.initials: P
authors.lastname: Véra
mesh_terms: D000368:Aged; D016001:Confidence Intervals; D003327:Coronary Disease / Q000175:diagnosis; D003935:Diagnostic Techniques, Cardiovascular; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013793:Thallium; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: C027549:thallium chloride; D013793:Thallium