Effect of Exposure Angulation on the Occupational Radiation Exposure during Cardiac Angiography: Simulation Study

Cardiac angiography to visualize the cardiac coronary artery for lesions causes a lot of radiation exposure dose to the interventional cardiologist. We evaluated the occupational radiation exposure to the interventional cardiologist based on changes to the angle of the X-ray tube used in cardiac angiography and calculated the conversion factor for effective dose in this study. To evaluate the occupational radiation exposure resulting from scattered radiation to interventional cardiologists, organ doses for eyeball, thyroid, and heart were calculated using Monte Carlo simulation with korean typical man(KTMAN) phantom at the left anterior oblique (LAO)30/cranial (CRAN)30, CRAN40, right anterior oblique (RAO)30/CRAN30, RAO30/caudal(CAUD)20, CAUD39, LAO40/CAUD35, and LAO40 positions in the femoral and the radial artery puncture. In this study, analysis of the different angles showed the highest radiation exposure on LAO30/CRAN30 and CRAN40 position, which were 150.65% and 135.3%, respectively, compared to AP angles. Therefore, to reduce occupational dose for interventional cardiologists, it is recommended that radiation protection, such as using radiation shield and personal protective equipment (PPE), be used at LAO30/CRAN30 and CRAN40 angulation, and the conversion factor for calculating the organ dose received by the interventional cardiologists based on patient dose can be applied for improved occupational dose management.

Pediatric Diagnostic Reference Levels for Diagnostic and Therapeutic Cardiac Catheterization in Japan

To propose Japanese national DRLs for air-kerma at the reference point (Ka,r), air-kerma area product (PKA), fluoroscopy time (FT), and number of cine images (CI) for four age groups. We posted a nationwide questionnaire to 132 facilities. Questions focused on identifying the procedure, age, weight, height, Ka,r, PKA, FT, and CI during diagnostic and therapeutic pediatric cardiac catheterization. For diagnostic cardiac angiography, the 75th percentile values were as follows; Ka,r: 103, 127, 194, and 351 mGy; PKA: 7.0, 12.3, 14.3, and 47.2 Gy.cm2; FT: 36.8, 30.7, 33.4, and 35.7 min; and CI: 2018, 2313, 2408, and 2016 images for less than one year, 1–5 years, 6–10 years, and 11–15 years respectively. For therapeutic cardiac angiography, the 75th percentile values were as follows: Ka,r: 146, 209, 130, and 501 mGy; PKA: 7.54, 16.0, 8.35, and 46.0 Gy.cm2; FT: 56.5, 52.0, 49.4, and 52.0 min; and CI: 4075, 4514, 3576, and 5984 images for less than one year, 1–5 years, 6–10 years, and 11–15 years respectively. Our survey of diagnostic and therapeutic cardiac catheterization in Japanese pediatric patients showed that all age-based Japanese 75th percentiles for the Ka,r, PKA, FT, and CI were higher than in other surveys. Based on the result of our study, it is necessary to establish DRLs for pediatric cardiac catheterization examinations in Japan, in order to optimize the safety of pediatric protocols for diagnostic and therapeutic cardiac catheterization.

Apical hypertrophic cardiomyopathy: an uncommon cause of exertional chest pain in children

Apical hypertrophic cardiomyopathy is an uncommon morphologic variant of hypertrophic cardiomyopathy, which is rarely diagnosed in childhood. To date, very few cases of asymptomatic children younger than 18 years have been reported in the literature. To the best of our knowledge, this is the first case of paediatric apical hypertrophic cardiomyopathy presenting with exertional chest pain, with characteristic electrocardiographic, echocardiographic, MRI, and cardiac angiography findings.