Digital subtraction angiography: feasibility of densitometric evaluation of left ventricular volumes and comparison to measurements obtained by the monoplane area-length-method

Monoplane 30° RAO area-length-method (ALM) measurements of enddiastolic and endsystolic left ventricular volumes and ejection fraction are based on geometric assumptions which may lead to erroneous results. Densitometric evaluation is an alternative on-line method when applied to digital imaging and is independent of ventricular shape. The value and limitations of densitometry are demonstrated in heart casts and in 54 patients. Densitometric evaluation exhibited a better agreement with true values in the phantom study than the ALM. The intra- and interobserver variability was remarkably lower for densitometry than for ALM. The presented data indicate that densitometry offers the potential for an objective and simple means of determining left ventricular volumes and ejection fraction during cardiac catheterization for digital imaging acquisition and processing systems