A national programme for patient and staff dose monitoring in interventional cardiology.

A national programme on patient and staff dose evaluation in interventional cardiology made in cooperation with the haemodynamic section of the Spanish Society of Cardiology has recently been launched. Its aim is to propose a set of national diagnostic reference levels (DRLs) for patients as recommended by the International Commission on Radiological Protection and to initiate several optimisation actions to improve radiological protection of both patients and staff. Six hospitals have joined the programme and accepted to submit their data to a central database. First to be acquired were the quality control data of the X-ray systems and radiation doses of patients and professionals. The results from 9 X-ray systems, 1467 procedures and staff doses from 43 professionals were gathered. Provisional DRLs resulted in 44 Gy cm(2) for coronary angiography and 78 Gy cm(2) for interventions. The X-ray systems varied up to a factor of 5 for dose rates in reference conditions. Staff doses showed that 50 % of interventional cardiologists do not use their personal dosemeters correctly.

Importance of dose settings in the x-ray systems used for interventional radiology: a national survey.

The purpose of this work was to investigate the differences in dose settings among the X-ray units involved in a national survey of patient doses in interventional radiology (IR). The survey was promoted by the National Society of IR and involved 10 centers. As part of the agreed quality control for the survey, entrance doses were measured in a 20-cm-thick acrylic phantom simulating a medium-sized patient. A standard digital subtraction angiography (DSA) imaging protocol for the abdomen was used at the different centers. The center of the phantom was placed at the isocenter of the C-arm system during the measurements to simulate clinical conditions. Units with image intensifiers and flat detectors were involved in the survey. Entrance doses for low, medium, and high fluoroscopy modes and DSA acquisitions were measured for a field of view of 20 cm (or closest). A widespread range of entrance dose values was obtained: 4.5-18.6, 9.2-28.4, and 15.4-51.5 mGy/min in low, medium, and high fluoroscopy mode, respectively, and 0.7-5.0 mGy/DSA image. The ratios between the maximum and the minimum values measured (3-4 for fluoroscopy and 7 for DSA) suggest an important margin for optimization. The calibration factor for the dose-area product meter was also included in the survey and resulted in a mean value of 0.73, with a standard deviation of 0.07. It seems clear that the dose setting for the X-ray systems used in IR requires better criteria and approaches.

A pilot experience launching a national dose protocol for vascular and interventional radiology.

The design of a national dose protocol for interventional radiology has been one of the tasks during the European SENTINEL Coordination Action. The present paper describes the pilot experience carried out in cooperation with the Spanish Society on Vascular and Interventional Radiology (SERVEI). A prospective sample of procedures was initially agreed. A common quality control of the X-ray systems was carried out, including calibration of the air kerma area product (KAP) meters. Occupational doses of the radiologists involved in the survey were also included in the survey. A total of 10 Spanish hospitals with interventional X-ray units were involved. Six hundred and sixty-four patient dose data were collected from 397 diagnostic and 267 therapeutic procedures. Occupational doses were evaluated in a sample of 635 values. The obtained KAP median/mean values (Gy.cm2) for the gathered procedures were: biliary drainage (30.6/68.9), fistulography (4.5/9.8), lower limb arteriography (52.2/60.7), hepatic chemoembolisation (175.8/218.3), iliac stent (45.9/73.2) and renal arteriography (39.1/59.8). Occupational doses (mean monthly values, in mSv) were 1.9 (over apron); 0.3 (under apron) and 4.5 (on hands). With this National experience, a protocol was agreed among the SENTINEL partners to conduct future similar surveys in other European countries.

Low-dose high-resolution CT of the chest in children and young adults: dose, cooperation, artifact incidence, and image quality.

OBJECTIVE: The radiation dose, artifact incidence, and image quality of high-resolution chest CT examinations performed with standard and low doses and patient cooperation were investigated in children and young adults. SUBJECTS AND METHODS: Three successive controlled studies were conducted in different groups of children and young adults, totaling 203 patients. Dosimetry of high-resolution CT was performed at 180, 50, and 34 mAs in three groups of 25 patients. Streak artifact incidence using alternating 50- and 34-mAs slices was assessed and correlated with patient compliance with breath-holding commands in 44 children. Image quality was evaluated in scans obtained with 34 versus 180 mAs in cooperative patients (n = 42) and in scans obtained with 50 versus 180 mAs in noncooperative patients (n = 42). Artifacts and image quality were assessed by controlled repeated interpretations. RESULTS: Radiation dose was 5.4+/-1.6 mSv for 180 mAs, 1.5+/-0.5 mSv for 50 mAs, and 1.1+/-0.3 mSv for 34 mAs. Cooperation was obtained in 66% of the patients. Artifacts were more frequently seen in scans of noncooperative patients (30%) and in 34-mAs scans (47%); the highest incidence was found using 34 mAs in noncooperative patients (60%, p = 0.02). No differences in image quality scores were seen in scans obtained with 50 mAs versus those obtained with 180 mAs in noncooperative patients (p<0.05), and small differences were found in scans obtained with 34 mAs versus those obtained with 180 mAs in cooperative patients for fissures (p = 0.005) and peripheral structures (p = 0.02). CONCLUSION: Low-dose high-resolution CT provided a significant reduction in radiation dose (72% for 50 mAs and 80% for 34 mAs) and good-quality images of the lung when performed with 50 mAs in noncooperative and 34 mAs in cooperative pediatric and young adult patients.