Local diagnostic reference levels for cardiac computed tomography

Introduction: Clinical applications of cardiac computed tomography in our center include the diagnosis of coronary arteries, assessment of their narrowing, evaluation of cardiac function, and assessment of the heart's structure. The aim of this study was the determination of local DRLs for cardiac CT sequence (designed to evaluate coronary arteries, function, and structure of the heart in one sequence) and calcium score sequence.Material and Methods: The research group consisted of 2234 patients undergoing cardiac computed tomography, including calcium score, cardiac CT angiography, evaluation of cardiac function and cardiac structure. The studies were conducted using a dual-source Somatom Force computed tomography scanner (2019, Siemens). An assessment of the dose received by the patient was performed based on the analysis of the volumetric tomographic dose index (CTDIvol) and the dose-length product (DLP), taking into account body mass index (BMI).Results: The DRL value for all patients undergoing cardiac computed tomography (one sequence including evaluation of calcium score, cardiac angiography, cardiac function, and cardiac structure) and calcium score sequence (in brackets) were 901.5 (92.3) mGy<middle dot>cm. When broken down by BMI category, the values were 869.9 (87.7) mGy<middle dot>cm, 880.9 (89.6) mGy<middle dot>cm, 889.3 (91.4) mGy<middle dot>cm, 941.0 (95.8) mGy<middle dot>cm, for underweight, normal BMI, overweight and obese patients, respectively.Conclusion: Diagnostic reference levels should be carefully determined, taking into account BMI, detailed information about the CT protocol, and type of CT scanner. Careful determination and regular updates of diagnostic reference levels are essential for optimizing the radiological protection of the patient.