Purpose: To describe the process of implementation of a non-invasive diagnostic strategy including cardiac CT and 13NH3PET/CT for patients with chest pain with low to medium risk for significant coronary artery disease, its effects on patient radiation burden and patient satisfaction concerning these types of cardiac imaging.
Methods: After defining the goals of the new imaging strategy by nuclear medicine physicians, cardiologists and radiologists, employees were trained and licensed for cardiac CT and a Siemens Somatom Definition Flash CT system was installed. A fast track diagnostic procedure was then created to enable low to intermediate risk patients to receive a coronary artery evaluation including diagnosis and treatment plan within 2 hours. For intermediate risk patients, processes and logistics were optimized in both the in-house cyclotron and PET/CT facility to enable a time-efficient rest/stress 13NH3PET/CT on a maximum of 3 Siemens Biograph PET/CT systems simultaneously with a total scan duration of 25 minutes. After implementation, the impact of the new scan procedures on radiation burden of patients was evaluated and patient satisfaction and scan procedure tolerability was measured using various questionnaires.
Results: The improved diagnostic strategy for chest pain patients was successfully implemented, replacing conventional MPS by more sophisticated techniques with substantially lower radiation burden. While conventional rest/stress MPS delivered an effective radiation dose of 11.8 mSv to patients, cardiac CT results in a dose of only 1.7±0.8 mSv (Flash protocol, used in 64% of scans), 4.7±2.9 mSv (Prospective ECG-triggering protocol, used in 24%) or 0.7±0.7 (calcium score only). Our 13NH3PET/CT procedure delivers a mean effective radiation dose of 1.4 mSv to patients. The fast track cardiac CT was rated an average 8.7 (out of 10) by patients for total satisfaction of the procedure (n=123 filled out questionnaires), and the 13NH3PET/CT procedure was also rated with an average of 8.7, according to the patient surveys (n=117).