Coronary artery calcium measurement with multi-detector row CT: In vitro assessment of effect of radiation dose

The authors assessed in vitro the effect of radiation dose on coronary artery calcium quantification with multi-detector row computed tomography. A cardiac phantom with calcified cylinders was scanned at various milliampere second settings (20-160 mAs). A clear tendency was found for image noise to decrease as tube current increased (P < .001). No tendency was found for the Agatson score or calcium volume and mass errors to vary with tube current. Calcium measurements were not significantly affected by the choice of tube current. Calcium mass error was strongly correlated with calcium volume error (P < .001). The calcium mass measurement was more accurate and less variable than the calcium volume measurement. (C) RSNA, 2002.