title: Cadmium-zinc-telluride myocardial perfusion imaging in obese patients.
abstract: We have evaluated the impact of increased body mass on the quality of myocardial perfusion imaging using a latest-generation γ-camera with cadmium-zinc-telluride semiconductor detectors in patients with high (≥40 kg/m(2)) or very high (≥45 kg/m(2)) body mass index (BMI).
  
  
  METHODS
  We enrolled 81 patients, including 18 with no obesity (BMI < 30 kg/m(2)), 17 in World Health Organization obese class I (BMI, 30-34.9 kg/m(2)), 15 in class II (BMI, 35-39.9 kg/m(2)), and 31 in class III (BMI ≥ 40 kg/m(2)), including 15 with BMI ≥ 45 kg/m(2). Image quality was scored as poor (1), moderate (2), good (3), or excellent (4). Patients with BMI ≥ 45 kg/m(2) and nondiagnostic image quality (≤2) were rescanned after repositioning to better center the heart in the field of view. Receiver-operating-curve analysis was applied to determine the BMI cutoff required to obtain diagnostic image quality (≥3).
  
  
  RESULTS
  Receiver-operating-curve analysis resulted in a cutoff BMI of 39 kg/m(2) (P < 0.001) for diagnostic image quality. In patients with BMI ≥ 40 kg/m(2), image quality was nondiagnostic in 81%; after CT-based attenuation correction this decreased to 55%. Repositioning further improved image quality. Rescanning on a conventional SPECT camera resulted in diagnostic image quality in all patients with BMI ≥ 45 kg/m(2).
  
  
  CONCLUSIONS
  Patients with BMI ≥ 40 kg/m(2) should be scheduled for myocardial perfusion imaging on a conventional SPECT camera, as it is difficult to obtain diagnostic image quality on a cadmium-zinc-telluride camera.
authors.affiliation: Department of Radiology, Cardiac Imaging, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Fiechter
authors.forename: Cathérine
authors.initials: C
authors.lastname: Gebhard
authors.forename: Tobias A
authors.initials: TA
authors.lastname: Fuchs
authors.forename: Jelena R
authors.initials: JR
authors.lastname: Ghadri
authors.forename: Julia
authors.initials: J
authors.lastname: Stehli
authors.forename: Egle
authors.initials: E
authors.lastname: Kazakauskaite
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Herzog
authors.forename: Aju P
authors.initials: AP
authors.lastname: Pazhenkottil
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D016477:Artifacts; D015992:Body Mass Index; D002104:Cadmium; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009765:Obesity / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012372:ROC Curve; D013691:Tellurium; D015032:Zinc
chemical_list: C474490:CdZnTe; D002104:Cadmium; D015032:Zinc; D013691:Tellurium