Three-year clinical experience with VQ SPECT for diagnosing pulmonary embolism: diagnostic performance

Clin Imaging. 2014 Nov-Dec;38(6):831-5. doi: 10.1016/j.clinimag.2014.04.003. Epub 2014 Apr 23.


Ventilation-perfusion (VQ) single-photon emission computed tomography (SPECT) comprised the administration of SmartVent (n=386) or Technegas (n=1564) and 200 MBq (99m)Tc-MAA. 1406 scans were normal, 462 showed PE, 61 showed a singular subsegmental mismatched defect, 21 scans were non-diagnostic. 26% of scans performed with Technegas showed PE, compared to 15% with SmartVent. VQ SPECT had a sensitivity of 95.7%, specificity 98.6%, positive predictive value 95.7%, negative predictive value 98.6%. A normal VQ SPECT scan implied a more than ten-fold lower cause-specific mortality (1 in 1406) than a scan showing PE (1 in 116). NPV of a negative D-dimer was 94.3%.

Keywords: Fibrin fragment D; Multidetector computed tomography; Pulmonary embolism; Tomography, emission-computed, single-photon; Ventilation-perfusion scan.

MeSH terms

  • Female
  • Humans
  • Male
  • Middle Aged
  • Pulmonary Embolism / diagnostic imaging*
  • Radiopharmaceuticals
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Sodium Pertechnetate Tc 99m
  • Tomography, Emission-Computed, Single-Photon / methods*
  • Ventilation-Perfusion Ratio*


  • Radiopharmaceuticals
  • Technegas
  • Sodium Pertechnetate Tc 99m