Short communication: staff dose reduction during coronary angiography using low framing speed.

Radiation exposure of cardiac catheterization laboratory staff is a known occupational hazard, and efforts are made to obtain dose levels which are "as low as reasonably achievable". This study assessed the reduction in staff radiation exposure using cine framing at 12.5 f s-1 during coronary cineangiography, instead of 25 f s-1. Thermoluminescent dosemeters were used to measure equivalent dose at several sites for the operator, nurse assistant, and X-ray technician during 15 procedures at both frame rates. Patient-related and procedure-related variables were similar in the two groups of examinations. Mean equivalent dose absorbed (microSv) at the left side of the forehead was reduced by 61%, 60% and 36%, for the operator, nurse assistant and X-ray technician, respectively. With use of the lower frame rate similar reductions by 42%, 62% and 62% were measured at the thyroid level, and by 51%, 40% and 61% at the mid-thorax level. Cinefilming at low frame rates during coronary arteriography allows a substantial X-ray dose reduction at all body sites for all staff. Use of lower frame rates wherever possible is of special interest since it may also reduce patient radiation exposure.

[Radiologic practice and radioprotection in Italian hemodynamic laboratories]. / Pratica radiologica e radioprotezione nei laboratori di emodinamica italiani.

Increasing numbers of diagnostic and therapeutic cardiac catheterization procedures are performed in Italy each year. Radiation exposure of the cardiac catheterization laboratory staff is a known hazard, and there is growing public and professional concern over the risks of low-energy medical ionizing radiation for the patients. The aim of this study was to outline the range of current radiological and radiation protection practice in large-volume cardiac catheterization laboratories in Italy. In August 1994 a questionnaire was submitted to the chief invasive cardiologist of the 32 cardiac catheterization laboratories nation-wide having performed at least 1000 procedures in 1993. All laboratories responded. There were variations in both the radiologic technique (cine framing speed, mean film lengths and fluoroscopy times) and the radiation protection practice (use of shields, leaded collars and glasses, and sites where dosimeters are worn). In 22 of 32 laboratories the cardiologists were not aware of radiation exposure data, and only 6 laboratories could quote the exposure provided by their X-ray system or estimates of the dose absorbed by patients during diagnostic or therapeutic procedures. The results of this survey indicate that radiological practice, and techniques for measuring and reducing exposure of the personnel vary widely in cardiac catheterization laboratories in Italy. These data suggest also that reducing patients' radiation exposure is not, in general, considered to be a quality assurance priority by interventional cardiologists.

On-line quantitative coronary analysis in clinical practice: one step closer to reality?

Quantitative coronary analysis is widely used in studies of progression/regression and restenosis of coronary lesions. On-line digital systems are used in diagnostic coronary angiography, and as a guide in coronary interventions. The aim of this investigation was to test the reliability of measures obtained with one commercially available on-line equipment. Well-visualized coronary lesions from patient studies were analyzed for variability in single-frame measurement. Procedural factors affecting the consistency of measurements were identified by repeated visualization of the same coronary lesion with hand- and power-injection of contrast in various positions in the field of the image intensifier, and by imaging of steel phantoms in the same positions. Steel phantoms closely resembling coronary lesions as encountered in practice were visualized in the most favourable radiologic setting compatible with clinical situations. Accuracy and precision of measurements were found to be worse than reported in validation studies. This may be due to a host of variables which may need to be tested in each laboratory performing on-line quantitative coronary angiography, when data so obtained are to be used in clinical decision making or in research studies.