Accuracy of quantitative ventriculographic analysis at reduced frame rates

Objective: We measured the error in left ventricular (LV) volume and wall m otion measurement from recording contrast ventriculograms at 15 frames/sec instead of 30 frames/sec. Background: Angiograms are increasingly recorded at 15 frames/sec instead of 30 frames/sec to improve efficiency. However th e resulting error in quantitative analysis has not been evaluated. Methods: Contrast ventriculograms recorded at 30 frames/sec of 23 patients undergoi ng diagnostic studies were digitized from cine film. End diastolic volume ( EDV), end systolic volume (ESV), ejection fraction, anterior wall motion, a nd inferior wall motion were measured from a full set recorded at 30 frames /sec and from two reduced data sets at 15 frames/sec generated from the eve n and odd numbered frames. Intraobserver variability was compared with the error due to frame rate reduction. Results: The error due to frame rate red uction did not differ significantly from intraobserver variability (p > 0.1 for all), measuring 2.6 +/- 2.2 ml (r = 0.997) vs. 1.9 +/- 1.2 ml (r = 0.9 99), respectively for EDV, 2.4 +/- 1.8 ml (r = 0.991) vs. 2.1 +/- 1.7 ml (r = 0.994), respectively for ESV, and 0.2 +/- 0.2 percent (r = 0.981) vs. 0. 1 +/- 1.2 percent (r = 0.994), respectively for ejection fraction. The erro r and variability for wall motion were 0.3 +/- 0.3 SD (r = 0.928) vs. 0.2 /- 0.1 SD (r = 0.946), respectively for the anterior wall and 0.2 +/- 0.2 S D (r = 0.963) vs. 0.2 +/- 0.1 SD (r = 0.968), respectively for the inferior wall. Conclusion: Imaging the LV at 15 frames/sec does not cause a signifi cant error in measuring LV volume and function compared with imaging at 30 frames/sec. (C) 1999 Wiley-Liss, Inc.