[Teamwork for cardiac imaging: coronary computed tomography angiography and low-dose radiation exposure: a cardiology center experience].

BACKGROUND

Multidetector coronary computed tomography angiography (CCTA) is increasingly used for noninvasive imaging of the coronary arteries. Radiation exposure, however, is a potential limitation to a more extensive use of this imaging modality. We aimed to demonstrate that a professional teamwork approach, including a cardiologist and a radiologist in performing CCTA, may allow to obtain best quality exams with very low radiation doses.

METHODS

A total of 998 consecutive patients underwent CCTA in accordance with the most recent guidelines. The following procedures were undertaken to reduce the radiation dose: (a) preliminary cardiological evaluation to check for CCTA eligibility; (b) optimized heart rate control with beta-blockers and/or ivabradine; and (c) the use of nonstandardized computed tomography protocols and algorithms for dose reduction.

RESULTS

All the patients underwent a preliminary cardiological evaluation; 89% of them were pretreated with oral or intravenous beta-blockers and/or ivabradine; 806 patients (81%) were scanned by means of prospective gating, which allowed a radiation dose exposure of 161 ± 68.64 mGy; 192 patients (19%) underwent a retrospective gating protocol, with a radiation dose exposure of 1135.15 ± 485.87 mGy. In 13 patients (1%) CCTA was uninterpretable because of artifacts. Exam quality was not affected by the use of low-dose computed tomography scanning. Coronary calcium score and/or left ventricular functional analysis were never performed.

CONCLUSIONS

The preliminary selection and preparation of patients and optimized scanner utilization allow a substantial reduction in radiation dose for most of the patients submitted to CCTA without affecting image quality. In our experience, a team approach was necessary to allow a "low-dose learning curve" and a progressive reduction in radiation doses administered to patients by means of the prospective gating protocol.