Precision of digitized M-mode echocardiograms for clinical practice
European Heart Journal
|November 1, 1984
Summary
Digitizing M-Mode echocardiograms is useful for studying left ventricular function. Repeating the digitization process four times can improve precision for clinical use, making the data more reliable.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Imaging
Background:
- Computer digitization of M-Mode echocardiograms is a valuable research tool for assessing left ventricular function.
- Its clinical application requires understanding the technique's reproducibility to minimize imprecision.
Purpose of the Study:
- To evaluate the reproducibility of computer-digitized M-Mode echocardiograms for clinical application.
- To identify sources of imprecision in the digitization process.
Main Methods:
- Five normal M-Mode echocardiograms were digitized twice by four different operators using an Apple II computer.
- Analysis of variance was employed to identify sources of imprecision.
Main Results:
- The peak rate of change of diastolic left ventricular dimension (dD/dt) showed significant imprecision (95% CI +/- 6.5 cm s-1) due to replication variance (90%).
- Repeating digitization four times could theoretically reduce the confidence interval for dD/dt to +/- 3.6 cm s-1.
- Confidence intervals for diastolic left ventricular minor dimension, posterior wall thickness, and isovolumic relaxation time were also determined, with replication being the largest variance component.
Conclusions:
- Computer digitization of M-Mode echocardiograms can yield clinically useful data if reproducibility is known.
- Repeating the digitization process is the most effective method to reduce imprecision and enhance clinical utility.
