Radiation doses to patients from enteroclysis

The purpose of this study was to determine the patient doses during enteroclysis and compare them with the available bibliographical data. For 14 enteroclysis examinations, the dose-area product (DAP) meter readings, fluoroscopy time, number of radiographs and exposure data were recorded. From these data, the fluoroscopy and radiography contributions to DAP, the entrance surface dose (ESD) and the effective dose (E) for each examination were estimated. The mean DAP was 81 Gy cm(2) and the mean fluoroscopy time was 19.5 min. The fluoroscopy contribution to DAP was 77% and 8.7 films were acquired in each examination on average. The mean ESD and E were estimated to be 428 mGy and 21 mSv, respectively. The mean DAP and fluoroscopy time calculated in this study are quite high when compared with those reported in the literature, suggesting that the examination technique should be reviewed and the ways to reduce patient exposure without compromising the diagnostic quality should be acquired.     

Patient and endoscopist radiation doses during ERCP procedures

The aim of the study was to calculate radiation doses for patients and staff during interventional Endoscopic retrograde cholangiopancreatography (ERCP) procedures. Patient age (A), kerma-area product (KAP), fluoroscopy time (T) and total number of films (F) were collected for 157 interventional ERCP procedures. One endoscopist (>10 y of experience) monitored using a thermoluminescent dosemeter worn over the lead apron performed the ERCPs. Median (range) KAP was 3.1 Gy cm(-2) (0.1-106.7 Gy cm(-2)). Median (range) A, T and F were 72 y, 2.6 (0.2-26.0) min and 2 (1-4) images, respectively. No correlation was observed between KAP and A, T or F. Monthly endoscopist dose was negligible due to the use of lead apron, collar and two lead-articulated ceiling mounted shields. The endoscopist dose is minimal when using appropriate protective measures. Patient doses showed large variation that has to be further investigated.     

Evaluation of radiation dose during pacemaker implantations

The purpose was to evaluate patient radiation doses and compare with other interventional procedures. One hundred and twenty-eight procedures were carried out with a recently installed mobile undercouch C-arm machine with a 23-cm diameter image intensifier. The radiation dose is provided by the X-ray machine, in terms of cumulative dose (CD). Kerma-Area product (KAP) was then estimated from CD and the X-ray field size. Other patient parameters recorded were patient weight, age, kilovolt, milliampere and fluoroscopy time (T). Median (range) CD, KAP and T were 15.2 mGy (3.2-110 mGy), 6.3 Gy cm(2) (1.3-45.7 Gy cm(2)) and 5.2 (1.5-27.4 min) min, respectively. Median E was 1.1 mSv (conversion factor: 0.18 mSv per Gy cm(2)), which corresponds to approximately one lumbar spine X-ray radiography. The effective dose is much lower than a coronary angiography (8 mSv) or an electrophysiology study (6 mSv). Radiation dose is low compared with other interventional cardiology procedures.     

Patient skin dose assessment during CT-guided interventional procedures

The purpose of this study was to investigate patient skin doses in the most frequent computed tomography-guided interventional radiology procedures. The study includes 14 abdominal biopsies and 15 radiofrequency (RF) ablations. Patient skin dose was assessed by slow verification films. The technical factors recorded were: tube kilovoltage (kV(p)), tube load (mAs), slice thickness and the total number of slices (S). The median value of maximum entrance skin dose (ESD(M)) in biopsy was 108 mGy (9.5-282 mGy). S had a range of 4-152 with a median of 44 slices. Significant correlation was found between S and dose (r = 0.80). Median ESD(M) in RF ablation was 238 mGy (104-500 mGy). S had a range of 108-175 with a median of 155 slices. No significant correlation was found between S and dose. The large range of results show that a more extensive investigation should be performed. In summary, diagnostic procedures such as biopsy present patient skin doses that are relatively low. On the other hand, patient skin dose in RF ablation can be high and can reach values higher than the value that a slow verification film is capable of measuring (1.2 Gy). For these procedures, an alternative method should be investigated.