title: Perfusion SPECT in patients with suspected pulmonary embolism.
abstract: OBJECTIVE
  Ventilation/perfusion tomography (V/PSPECT), with new interpretation criteria and newer tracers for ventilation imaging, has markedly improved the diagnostic yield in acute pulmonary embolism (PE). Here, we evaluated the diagnostic performance of perfusion SPECT (PSPECT) without ventilation imaging.
  
  
  METHODS
  We studied 152 patients with clinically suspected PE who had been examined with both V/PSPECT and multidetector computed tomographic angiography (MD-CTA). The diagnosis or exclusion of PE was decided by the referring clinician based on both the V/PSPECT and/or MD-CTA findings in combination with the clinical findings. PSPECT images were retrospectively examined by a physician with experience in the interpretation of planar perfusion scans who was blinded to clinical, V/PSPECT and MD-CTA data. PSPECT images were interpreted without the aid of chest radiography. All the patients who were deemed to have PE were given anticoagulant therapy.
  
  
  RESULTS
  Of the 152 patients, 59 (39%) received a final diagnosis of PE, and 19 (32%) had associated cardiopulmonary diseases such as pneumonia, COPD, or left heart failure. PSPECT correctly identified 53 (90%) of the 59 patients with PE. The specificity was 88 of 93 (95%). None of the PSPECT images was rated nondiagnostic. PSPECT yielded an overall diagnostic accuracy of 93% (95% confidence interval, CI, 87-96%). At the observed PE prevalence of 39 %, the positive and negative predictive values of PSPECT were 91% (95% CI, 80-97%) and 94% (95% CI, 86-97%), respectively.
  
  
  CONCLUSIONS
  In managing critically ill patients, PSPECT might be a valid alternative to V/PSPECT or MD-CTA since it was able to identify most patients with PE with a low false-positive rate and no inconclusive results.
authors: Department of Clinical Physiology, Skåne University Hospital, Lund, Sweden. marika.bajc@med.lu.se
authors: Marika
authors: M
authors: Bajc
authors: Massimo
authors: M
authors: Miniati
authors: Jonas
authors: J
authors: Jögi
authors: Paul D
authors: PD
authors: Stein
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011875:Radionuclide Angiography; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
references: J Nucl Med. 2008 Nov;49(11):1741-8
references: 18927339
references: Am J Respir Crit Care Med. 2011 Sep 15;184(6):708-14
references: 21680946
references: Radiology. 2007 Dec;245(3):742-50
references: 17923509
references: Am J Respir Crit Care Med. 1996 Nov;154(5):1387-93
references: 8912753
references: Am J Respir Crit Care Med. 1999 Mar;159(3):864-71
references: 10051264
references: N Engl J Med. 2010 Jul 1;363(1):1-4
references: 20573919
references: Eur J Nucl Med Mol Imaging. 2009 Sep;36(9):1528-38
references: 19629478
references: Med Sci Monit. 2006 Feb;12(2):PI9-13
references: 16449959
references: J Intern Med. 2008 Oct;264(4):379-87
references: 18823506
references: Radiology. 2010 Aug;256(2):625-32
references: 20551182
references: Radiology. 2011 Jan;258(1):164-73
references: 21115875
references: Int J Cardiovasc Imaging. 2012 Oct;28(7):1799-805
references: 22228471
references: Am J Cardiol. 1979 Mar;43(3):669-71
references: 420118
references: J Nucl Med. 2001 Aug;42(8):1288-94
references: 11483693
references: Eur J Nucl Med Mol Imaging. 2009 Aug;36(8):1356-70
references: 19562336
references: J Nucl Med. 2009 Dec;50(12):1987-92
references: 19910421
references: N Engl J Med. 2006 Jun 1;354(22):2317-27
references: 16738268
references: JAMA. 1990 May 23-30;263(20):2753-9
references: 2332918