Ventricular short-axis measurements in patients with pulmonary embolism: effect of ECG-gating on variability, accuracy, and risk prediction

Eur J Radiol. 2012 Sep;81(9):2195-202. doi: 10.1016/j.ejrad.2011.03.067. Epub 2011 Oct 5.


Objective: To assess prospectively the intra- and interobserver variability, accuracy, and prognostic value of right and left ventricular short-axis diameter (RVd and LVd) measurements for risk stratification in patients with pulmonary embolism (PE) using ECG-gated compared to non-gated CT.

Materials and methods: Sixty consecutive patients (33 women; mean age 58.7±10.3 years) with suspicion of PE underwent both non-gated and ECG-gated chest CT. RVd and LVd on four-chamber views and intra- and interobserver agreements were calculated for both protocols. RVd/LVd ratios were calculated and were related to 30-days adverse clinical events using receiver operating characteristics with area-under-the-curve (AUC) analyses.

Results: Both inter- and intraobserver variability showed narrower limits of agreement for all measurements with ECG-gated as compared to non-gated CT. Diameter measurements were significantly lower using non-ECG-gated CT as compared to ECG-gated CT for RVd and LVd (both p<.05). The AUC for the RVd/LVd ratio from ECG-gated CT was significantly larger than that from non-gated CT (0.956, 95% CI: 0.768-0.999 versus 0.675, 95% CI: 0.439-0.860; p=.048).

Conclusion: RVd and LVd measurements from ECG-gated chest CT show less intra- and interobserver variability and more accurately reflect ventricular function. In our patient cohort ECG-gated chest CT allows better prediction of short-term outcome of patients with acute PE that needs to be validated in a larger outcome study.

MeSH terms

  • Aged
  • Angiography / methods
  • Cardiac-Gated Imaging Techniques / methods*
  • Female
  • Heart Ventricles / diagnostic imaging*
  • Humans
  • Male
  • Middle Aged
  • Observer Variation
  • Pulmonary Embolism / complications*
  • Pulmonary Embolism / diagnostic imaging*
  • Tomography, X-Ray Computed / methods
  • Ventricular Dysfunction, Left / diagnostic imaging*
  • Ventricular Dysfunction, Left / etiology*