Incidental findings of cardiac MSCT: who might benefit from scanning the entire thorax on Ca score imaging?

PURPOSE

We aimed to report incidental noncoronary findings of coronary MSCT angiography and to evaluate the feasibility of scanning the entire thorax on Ca score imaging.

METHODS

514 patients underwent cardiac MSCT. Instead of scanning just the heart, 124 of them were scanned extensively from the lung apex to the base in order to evaluate the entire thorax for additional findings. Furthermore, we calculated dose length product (DLP) in order to determine mean increase of radiation exposure resulting from lengthened scan field.

RESULTS

Coronary artery disease were established in 122 patients (24%) and 273 noncoronary findings were identified in 189 patients (37%). 37 pulmonary nodules (PN) > or =5 mm, 6 of which were over the level of pulmonary trunk, were detected. The mean age (62+/-8 vs.49+/-10, respectively; p<0.0001) and the smoking rate (74% vs. 56%, respectively; p<0.05) of the patients with PN were significantly higher than subjects without PN. All patients with PN over the level of pulmonary artery were smokers >50 of age. On Ca score imaging, radiation exposure of widely scanned group was significantly higher than the others (221.3+/-35.2 mGy cm vs.145.3+/-11.7 mGy cm of DLP, respectively; p<0.0001).

CONCLUSION

Since MSCT data contain also information about the other structures in the thorax, the images should be evaluated by radiologist in addition to cardiologist. It seems reasonable to scan the entire thorax on Ca score imaging for smokers over 50 in order to detect pulmonary nodules having malignancy potential.