COMPARISON OF EJECTION FRACTION USING MUGA SCANNING AND 3D ECHOCARDIOGRAPHY.
Peter A. Dutchak, Daniel Brouillard, Murray F. Matangi
OBJECTIVE: To compare ejection fraction (EF) by 3D echocardiography (ECHO) and MUGA.
METHODS: 68 patients referred for MUGA scanning also underwent 3D ECHO for measurement of EF. The 3D ECHO was performed first and was followed immediately by MUGA scanning. The 3D ECHO and MUGA scanning analysis for EF were performed by two separate investigators. 3D images were acquired using a GE VIVID E9 system with a 4V probe. These images were then analysed using the TOMTEC 4D LV volumes and EF analysis system. Each investigator was blinded to the EF results of the other. The EF data from 3D ECHO and MUGA scanning was then collected and analyzed. A paired t test was used to assess differences between the mean values for each method. A p value of <0.05 was considered statistically significant. A Bland-Altman scatter plot was used to assess the inter-changeability of the two methods. The methods were considered to be interchangeable if 95% of data points were within ± 1.95 standard deviations from the mean difference between the two methods.
RESULTS:Of the 68 MUGA scans only 50 3D ECHOs had analysable images. There were 13 females and 37 males with a mean age of 64.8 ± 13.6. The mean EF by MUGA was 45.7 ± 12.2% compared to 46.2 ± 11.3% by 3D ECHO (P = 0.5538). The Bland-Altman scatter plot (see figure 1.) shows that 98% of data points lay within ± 1.96 standard deviations from the mean difference of the two methods.
CONCLUSION: When image quality allows, 3D ECHO offers a comparable alternative to MUGA scanning for the measurement of EF. The Bland-Altman scatter plot indicates these methods are interchangeable. This may have important clinical implications with respect to patients requiring frequent serial measurements of EF, which can be done, reliably in the absence of radiation exposure.