Influence of temporal smoothing on quantitation of left ventricular function by gated blood pool scintigraphy | JoVE Visualize

Influence of temporal smoothing on quantitation of left ventricular function by gated blood pool scintigraphy

R O Bonow¹, S L Bacharach, C Crawford-Green

¹Cardiology Branch, National Heart, Lung, and Blood Institute, Bethesda, Maryland.

The American Journal of Cardiology|October 15, 1989

View abstract on PubMed

Summary

Temporal smoothing of left ventricular (LV) function data can cause significant errors in systolic and diastolic function indexes. This effect is more pronounced with lower temporal resolution, potentially leading to severe underestimation of peak filling and ejection rates.

Area of Science:

Cardiovascular imaging and analysis
Nuclear cardiology
Medical physics

Background:

Left ventricular (LV) function is commonly assessed using radionuclide angiography.
LV time-activity curves are often smoothed to compute systolic and diastolic function indexes.
Temporal smoothing may introduce systematic errors in these computations.

Purpose of the Study:

To assess the impact of temporal smoothing on LV systolic and diastolic function indexes.
To evaluate the effect of different smoothing levels and temporal resolutions on these indexes.
To determine the clinical significance of smoothing-induced errors in various patient groups.

Main Methods:

High temporal resolution (20 ms/point) LV time-activity curves were acquired in 113 normal subjects, 175 CAD patients, and 171 HCM patients.
Curves were subjected to 0-, 3-, 5-, 7-, and 9-point temporal smoothing.
Analysis was repeated with lower temporal resolution data (40 ms/point).

Main Results:

Increased smoothing progressively underestimated ejection fraction (up to 5%) and peak ejection rate (up to 14%).
Peak filling rate was more severely affected, with 9-point smoothing reducing it by up to 23% in normal subjects.
Errors were compounded at lower temporal resolution, with peak filling rate underestimation reaching 46% in normal subjects.

Conclusions:

Temporal smoothing of LV time-activity curves introduces significant systematic errors in LV systolic and diastolic function indexes.
These errors are particularly pronounced with poor temporal resolution and affect peak filling and ejection rates more than ejection fraction.
Findings are relevant to other imaging modalities like MRI and cine-CT that assess LV function from volume curves.