Simple single-section method for measurement of left and right atrial volumes with electron-beam CT

Rationale and Objectives. The authors estimated left and right atrial volumes by using a simple method of measurement with nonenhanced electron-beam computed tomography (CT). Materials and Methods. One hundred sixty-four contrast material-enhanced electron-beam CT studies were divided into two groups. Group 1, which included 104 studies, was used to develop the measurement method (ie, the formulas) for measuring left and right atrial volumes from a nonenhanced study. Group 2 consisted of 60 studies on which the validity of the method was rested. Measurement of left and right atrial volumes was performed on all section levels by tracing the respective atrial borders for each section, then multiplying the area by section thickness and summing the resultant volumes. Results. Calculated left and right atrial volumes were derived by using the biggest atrial area and cephalic-caudal span. The span was equal to section thickness times the number of sections in which the atria were present. Linear regression analysis formulas were acquired with the biggest atrial area and cephalic-caudal span. Left and right atrial calculated volumes were obtained with these formulas and demonstrated a significant good relation (r > .95, P < .001) and a difference of less than 11% (P < .05) in absolute values between measured and calculated volumes. Intraobserver, interobserver, and interstudy reproducibility were excellent, with less than 10% difference in absolute values. Conclusion. Left and right atrial volumes can be accurately estimated from a single midventricular section by using nonenhanced electron-beam CT.