The addition of a leaded arm sleeve to leaded aprons further decreases operator upper outer quadrant chest wall radiation dose during fluoroscopically guided interventions.

OBJECTIVE: Breast cancer most commonly occurs in the upper outer quadrant (UOQ) chest wall (CW). The effectiveness of routine leaded aprons to protect this region of the body in interventionalists during fluoroscopically guided interventions (FGIs) is unknown. Given the high lifetime attributable risks of prolonged occupational exposure to ionizing radiation and the increasing number of practicing female vascular surgeons and interventionalists, we sought to determine if the use of a leaded arm shield would offer additional protection to the lateral CW and axilla in operators compared with routine leaded aprons. METHODS: Effectiveness of leaded sleeves in attenuating radiation dose to the axilla and UOQ was evaluated in clinical practice and simulated scenarios. In the clinical setting, optically stimulated luminescence nanoDot detectors were placed at the UOQ lateral CW position, both over and under a standard leaded apron vest with and without the addition of an antimony/bismuth Enviro-Lite sleeve on two vascular surgeons performing FGIs. In the simulation, nanoDots were similarly placed on an anthropomorphic phantom positioned to represent a primary operator performing right femoral access. Fluorography was performed on 12-inch-thick acrylic scatter phantom at 80 kVp for an exposure of 3 Gy reference air kerma. Experiments were done with and without the sleeve. Paired Wilcoxon and χ2 tests were performed to identify the statistical significance of radiation attenuation. RESULTS: Operator UOQ CW dose was measured during 61 FGIs: 33 cases (54%) with and 28 cases (46%) without the sleeve. Median procedure reference air kerma and fluoroscopy time was 180 mGy (interquartile range [IQR], 85-447 mGy) and 21 minutes (IQR, 11-39 minutes) when the sleeve was worn vs 100 mGy (IQR, 67-270 mGy) and 11 minutes (IQR, 6.3-25 minutes) without the sleeve. Radiation dose to the operator's UOQ was reduced by 96% (IQR, 85%-96%) when the sleeve was present and by 62% (IQR, 44%-82%; P < .001) without the sleeve. In the simulated setting, the sleeve reduced the radiation dose to the UOQ compared with the apron alone (96% vs 67%; P < .001). CONCLUSIONS: Routine leaded aprons do attenuate the majority of UOQ chest wall radiation dose; however, the addition of a lead-equivalent sleeve further significantly reduces this dose. Because this area of the body has a high incidence of cancer formation, additional protection, especially to female interventionalists, seems prudent. Vascular surgeons should consider using a protective sleeve with their personal protective equipment when performing complex fluoroscopically guided procedures.

Dual fluoroscopy with live-image digital zooming significantly reduces patient and operating staff radiation during fenestrated-branched endovascular aortic aneurysm repair.

OBJECTIVE: Fenestrated-branched endovascular aneurysm repair (F/B-EVAR) is a complex procedure that generates high radiation doses. Magnification aids in vessel cannulation but increases radiation. The aim of the study was to compare radiation doses to patients and operating room staff from two fluoroscopy techniques, standard magnification vs dual fluoroscopy with live-image digital zooming during F/B-EVAR. METHODS: An observational, prospective, single-center study of F/B-EVAR procedures using Philips Allura XperFD20 equipment (Philips Healthcare, Amsterdam, The Netherlands) was performed during a 42-month period. Intravascular ultrasound, three-dimensional fusion, and extreme collimation were used in all procedures. Intraoperative live-image processing was performed with two imaging systems: standard magnification in 123 patients (81%) and dual fluoroscopy with live-image digital zooming in 28 patients (18%). In the latter, the live "processed" zoomed images are displayed on examination displays and live images are displayed on reference displays. The reference air kerma was collected for each case and represents patient dose. Operating staff personal dosimetry was collected using the DoseAware system (Philips Healthcare). Patient and staff radiation doses were compared using nonparametric tests. RESULTS: Mean age was 71.6 ± 11.4 years. The median body mass index was 27 kg/m2 (interquartile range [IQR], 24.4-30.6 kg/m2) and was the same for both groups. Procedures performed with dual fluoroscopy with digital zooming demonstrated significantly lower median patient (1382 mGy [IQR, 999-2045 mGy] vs 2458 mGy [IQR, 1706-3767 mGy]; P < .01) and primary operator radiation doses (101 µSv [IQR, 34-235 µSv] vs 266 µSv [IQR, 104-583 µSv]; P < .01) compared with standard magnification. Similar significantly reduced radiation doses were recorded for first assistant, scrub nurse, and anesthesia staff in procedures performed with dual fluoroscopy. According to device design, procedures performed with four-fenestration/branch devices generated higher operator radiation doses (262 µSv [IQR, 116.5-572 µSv] vs 171 µSv [IQR, 44-325 µSv]; P < .01) compared with procedures with three or fewer fenestration/branches. Among the most complex design (four-vessel), operator radiation dose was significantly lower with digital zooming compared with standard magnification (128.5 µSv [IQR, 70.5-296 µSv] vs 309 µSv [IQR, 150-611 µSv]; P = .01). CONCLUSIONS: Current radiation doses to patients and operating personnel are within acceptable limits; however, dual fluoroscopy with live-image digital zooming results in dramatically lower radiation doses compared with the standard image processing with dose-dependent magnification. Operator radiation doses were reduced in half during procedures performed with more complex device designs when digital zooming was used.

Radiation doses and image quality of abdominal CT scans at different patient sizes using spectral detector CT scanner: a phantom and clinical study.

PURPOSE: To compare radiation dose and image quality for abdominal CTs performed on a spectral detector CT (SDCT) and a comparable single-energy conventional CT scanner for patients of different sizes. METHODS: Four semi-anthropomorphic phantoms were scanned on an SDCT (IQon, Philips Healthcare) and a comparable single-energy CT (iCT 256, Philips Healthcare) under matched scan parameters. Image noise and radiation dose were compared. For the HIPAA-compliant, IRB-approved retrospective cohort patient study, radiation dose was compared after adjusting for patient water equivalent diameter. Difference in subjective and objective image quality was assessed on a subset of 50 patients scanned on both scanners by two readers. RESULTS: CTDIvol and noise from SDCT were higher than conventional CT for all phantoms, with a relative difference of 7.8% (range 5.3-14%) for radiation dose and average difference of 9.0% (range 5.5-11%) for noise. 718 SDCT and 937 conventional CT patients were included in the patient study. CTDIvol for SDCT patients tends to be lower for smaller patients (- 2%, 95% confidence interval (- 5%, - 0.2%) for 200 mm water equivalent diameter) and higher for larger patients compared to conventional CT (8%, (6%, 11%) for 400 mm). No difference was seen for subjective image quality, SNR, CNR, or image noise between the two scanners, except for higher image noise in the portal vein and higher signal in the aorta on SDCT. CONCLUSION: Radiation dose for abdominal CT performed on SDCT is similar to the dose on a conventional CT for average size patients, lower for smaller patients, and slightly higher for larger patients. Image quality is similar between the two scanners.

Patient and operating room staff radiation dose during fenestrated/branched endovascular aneurysm repair using premanufactured devices.

INTRODUCTION: Fenestrated endovascular aneurysm repair (FEVAR) is the highest radiation dose procedure performed by vascular surgeons. We sought to characterize the radiation dose to patients and staff during FEVAR procedures with different premanufactured devices. METHODS: A single-center prospective study of FEVARs was performed over 24 months. Three FEVAR devices were included: off-the-shelf (OTS; t-Branch, p-Branch), Zenith Fenestrated (ZFen), and investigational custom-made devices (CMDs). Radiation doses to the surgeon, trainee, anesthesiologist, and scrub/circulating nurses were measured using a personal dosimetry system (DoseAware, Philips Healthcare, Amsterdam, The Netherlands). Procedure type, patient body mass index (BMI), reference air kerma (RAK), and kerma area product (KAP) were recorded. RAK and KAP were corrected for BMI based on an exponential fit of fluoroscopy dose rate and the dose per radiographic frame. Operator dose was corrected for BMI by the ratio of corrected to actual KAP. A one-sided Wilcox rank-sum test was used to compare personnel radiation doses, RAKs, and KAPs between procedure types. Statistical significance was set at P ≤ .05. RESULTS: There were 80 FEVARs performed by a single surgeon on a Philips Allura XperFD20 fluoroscopy system equipped with Clarity technology. Average BMI was 27 kg/m2. Sixty CMDs (36 four-, 21 three-, and 3 two-vessel fenestrations), 11 ZFens (8 three- and 3 two-vessel fenestrations), and 9 OTS devices (4 p-Branch, 5 t-Branch) were included. ZFens had significantly lower patient (1800 mGy vs 2950 mGy; P = .004), operator (120 µSv vs 370 µSv; P = .004), assistant (60 µSv vs 210 µSv; P = .003), circulator (10 µSv vs 30 µSv; P = .049), and scrub nurse dose (10 µSv vs 40 µSv; P = .02) compared with CMDs. OTS devices had significantly lower operator (220 µSv vs 370 µSv; P = .04), assistant (110 µSv vs 210 µSv; P = .02), and circulator doses (4 µSv vs 30 µSv; P = .001) compared with CMDs. Four-vessel fenestrated devices had significantly higher patient dose (3020 mGy) compared with three-vessel FEVARs (2670 mGy; P = .03) and two-vessel FEVARs (1600 mGy; P = .0007), and significantly higher operator dose (440 µSv) compared with three-vessel FEVARs (170 µSv; P = .0005). Patient dose was lowest with ZFens. Operating room personnel dose was lower with ZFens and OTS devices compared with CMDs. Four-vessel fenestrations required significantly more radiation compared with those involving three-vessel fenestrations; however, the dose increase was only 12% and should not preclude operators from extending coverage, if anatomically required. CONCLUSIONS: Overall, patient and personnel radiation doses during FEVAR with all devices were within acceptable limits and lower in our series than previously reported.

Radiation brain dose to vascular surgeons during fluoroscopically guided interventions is not effectively reduced by wearing lead equivalent surgical caps.

OBJECTIVE: Radiation to the interventionalist's brain during fluoroscopically guided interventions (FGIs) may increase the incidence of cerebral neoplasms. Lead equivalent surgical caps claim to reduce radiation brain doses by 50% to 95%. We sought to determine the efficacy of the RADPAD (Worldwide Innovations & Technologies, Lenexa, Kan) No Brainer surgical cap (0.06 mm lead equivalent at 90 kVp) in reducing radiation dose to the surgeon's and trainee's head during FGIs and to a phantom to determine relative brain dose reductions. METHODS: Optically stimulated, luminescent nanoDot detectors (Landauer, Glenwood, Ill) inside and outside of the cap at the left temporal position were used to measure cap attenuation during FGIs. To check relative brain doses, nanoDot detectors were placed in 15 positions within an anthropomorphic head phantom (ATOM model 701; CIRS, Norfolk, Va). The phantom was positioned to represent a primary operator performing femoral access. Fluorography was performed on a plastic scatter phantom at 80 kVp for an exposure of 5 Gy reference air kerma with or without the hat. For each brain location, the percentage dose reduction with the hat was calculated. Means and standard errors were calculated using a pooled linear mixed model with repeated measurements. Anatomically similar locations were combined into five groups: upper brain, upper skull, midbrain, eyes, and left temporal position. RESULTS: This was a prospective, single-center study that included 29 endovascular aortic aneurysm procedures. The average procedure reference air kerma was 2.6 Gy. The hat attenuation at the temporal position for the attending physician and fellow was 60% ± 20% and 33% ± 36%, respectively. The equivalent phantom measurements demonstrated an attenuation of 71% ± 2.0% (P < .0001). In the interior phantom locations, attenuation was statistically significant for the skull (6% ± 1.4%) and upper brain (7.2% ± 1.0%; P < .0001) but not for the middle brain (1.4% ± 1.0%; P = .15) or the eyes (-1.5% ± 1.4%; P = .28). CONCLUSIONS: The No Brainer surgical cap attenuates direct X rays at the superficial temporal location; however, the majority of radiation to an interventionalist's brain originates from scatter radiation from angles not shadowed by the cap as demonstrated by the trivial percentage brain dose reductions measured in the phantom. Radiation protective caps have minimal clinical relevance.

New image-processing and noise-reduction software reduces radiation dose during complex endovascular procedures.

BACKGROUND: A new proprietary image-processing system known as AlluraClarity, developed by Philips Healthcare (Best, The Netherlands) for radiation-based interventional procedures, claims to lower radiation dose while preserving image quality using noise-reduction algorithms. This study determined whether the surgeon and patient radiation dose during complex endovascular procedures (CEPs) is decreased after the implementation of this new operating system. METHODS: Radiation dose to operators, procedure type, reference air kerma, kerma area product, and patient body mass index were recorded during CEPs on two Philips Allura FD 20 fluoroscopy systems with and without Clarity. Operator dose during CEPs was measured using optically stimulable, luminescent nanoDot (Landauer Inc, Glenwood, Ill) detectors placed outside the lead apron at the left upper chest position. nanoDots were read using a microStar ii (Landauer Inc) medical dosimetry system. For the CEPs in the Clarity group, the radiation dose to surgeons was also measured by the DoseAware (Philips Healthcare) personal dosimetry system. Side-by-side measurements of DoseAware and nanoDots allowed for cross-calibration between systems. Operator effective dose was determined using a modified Niklason algorithm. To control for patient size and case complexity, the average fluoroscopy dose rate and the dose per radiographic frame were adjusted for body mass index differences and then compared between the groups with and without Clarity by procedure. Additional factors, for example, physician practice patterns, that may have affected operator dose were inferred by comparing the ratio of the operator dose to procedural kerma area product with and without Clarity. A one-sided Wilcoxon rank sum test was used to compare groups for radiation doses, reference air kermas, and operating practices for each procedure type. RESULTS: The analysis included 234 CEPs; 95 performed without Clarity and 139 with Clarity. Practice patterns of operators during procedures with and without Clarity were not significantly different. For all cases, procedure radiation dose to the patient and the primary and assistant operators were significantly decreased in the Clarity group by 60% compared with the non-Clarity group. By procedure type, fluorography dose rates decreased from 44% for fenestrated endovascular repair and up to 70% with lower extremity interventions. Fluoroscopy dose rates also significantly decreased, from about 37% to 47%, depending on procedure type. CONCLUSIONS: The AlluraClarity system reduces the patient and primary operator's radiation dose by more than half during CEPs. This feature appears to be an effective tool in lowering the radiation dose while maintaining image quality.

Surgeon radiation dose during complex endovascular procedures.

BACKGROUND: Surgeon radiation dose during complex fluoroscopically guided interventions (FGIs) has not been well studied. We sought to characterize radiation exposure to surgeons during FGIs based on procedure type, operator position, level of operator training, upper vs lower body exposure, and addition of protective shielding. METHODS: Optically stimulable, luminescent nanoDot (Landauer, Inc, Glenwood, Ill) detectors were used to measure radiation dose prospectively to surgeons during FGIs. The nanoDot dosimeters were placed outside the lead apron of the primary and assistant operators at the left upper chest and left lower pelvis positions. For each case, the procedure type, the reference air kerma, the kerma-area product, the relative position of the operator, the level of training of the fellow, and the presence or absence of external additional shielding devices were recorded. Three positions were assigned on the right-hand side of the patient in decreasing relative proximity to the flat panel detector (A, B, and C, respectively). Position A (main operator) was closest to the flat panel detector. Position D was on the left side of the patient at the brachial access site. The nanoDots were read using a microSTARii medical dosimetry system (Landauer, Inc) after every procedure. The nanoDot dosimetry system was calibrated for scattered radiation in an endovascular suite with a National Institute of Standards and Technology traceable solid-state radiation detector (Piranha T20; RTI Electronics, Fairfield, NJ). Comparative statistical analysis of nanoDot dose levels between categories was performed by analysis of variance with Tukey pairwise comparisons. Bonferroni correction was used for multiple comparisons. RESULTS: There were 415 nanoDot measurements with the following case distribution: 16 thoracic endovascular aortic repairs/endovascular aneurysm repairs, 18 fenestrated endovascular aneurysm repairs (FEVARs), 13 embolizations, 41 lower extremity interventions, 10 fistulograms, 13 visceral interventions, and 3 cerebrovascular procedures. The mean operator effective dose for FEVARs was higher than for other case types (P < .03), 20 µSv at position A and 9 µSv at position B. For all case types, position A (9.0 µSv) and position D (20 µSv) received statistically higher effective doses than position B (4 µSv) or position C (0.4 µSv) (P < .001). However, the mean operator effective dose for position D was not statistically different from that for position A. The addition of the lead skirt significantly decreased the lower body dose (33 ± 3.4 µSv to 6.3 ± 3.3 µSv) but not the upper body dose (6.5 ± 3.3 µSv to 5.7 ± 2.2 µSv). Neither ceiling-mounted shielding nor level of fellow training affected operator dose. CONCLUSIONS: Surgeon radiation dose during FGIs depends on case type, operator position, and table skirt use but not on the level of fellow training. On the basis of these data, the primary operator could perform approximately 12 FEVARs/wk and have an annual dose <10 mSv, which would not exceed lifetime occupational dose limits during a 35-year career. With practical case loads, operator doses are relatively low and unlikely to exceed occupational limits.

Deterministic effects after fenestrated endovascular aortic aneurysm repair.

BACKGROUND: Endovascular aortic aneurysm repairs (EVARs) with fenestrated (FEVAR) stent grafts are high radiation dose cases, yet no skin injuries were found retrospectively in our 61 cases with a mean peak skin dose (PSD) of 6.8 Gy. We hypothesize that skin injury is under-reported. This study examined deterministic effects in FEVARs after procedural changes implemented to detect skin injury. METHODS: All FEVARs during a 6-month period with a radiation dose of 5 Gy reference air kerma (RAK; National Council on Radiation Protection and Measurements threshold for substantial radiation dose level [SRDL]) were included. Patients were questioned about skin erythema, epilation, and necrosis, with a physical examination of the back completed daily until discharge and then at 2 and 4 weeks and at 3 and 6 months. PSD distributions were calculated with custom software using input data from fluoroscopic machine logs. These calculations have been validated against Gafchromic (Ashland Inc, Covington, Ky) film measurements. Dose was summed for the subset of patients with multiple procedures ≤6 months of the SRDL event, consistent with the joint commission recommendations. RESULTS: Twenty-two patients, 21 FEVARs and one embolization, reached an RAK of 5 Gy. The embolization procedure was excluded from review. The average RAK was 7.6 ± 2.0 Gy (range, 5.1-11.4 Gy), with a mean PSD of 4.8 ± 2.0 Gy (range, 2.3-10.4 Gy). Fifty-two percent of patients had multiple endovascular procedures ≤6 months of the SRDL event. The mean RAK for this subset was 10.0 ± 2.9 Gy (range, 5.5-15.1 Gy), with a mean PSD of 6.6 ± 1.9 Gy (range, 3.4-9.4 Gy). One patient died before the first postoperative visit. No radiation skin injuries were found. Putative risk factors for skin injury were evaluated and included smoking (32%), diabetes (14%), cytotoxic drugs (9%), and fair skin type (91%). No other risk factors were present (hyperthyroidism, collagen vascular disorders). CONCLUSIONS: Deterministic skin injuries are uncommon after FEVAR, even at high RAK levels, regardless of cumulative dose effects. This study addresses the concern of missed injuries based on the retrospective clinical examination findings that were published in our previous work. Even with more comprehensive postoperative skin examinations and patient questioning, the fact that no skin injuries were found suggests that radiation-induced skin injuries are multifactorial and not solely dose dependent.

Understanding and using fluoroscopic dose display information.

Fluoroscopically guided procedures are an area of radiology in which radiation exposure to the patient is highly operator dependent. Modern fluoroscopy machines display a variety of information, including technique factors, field of view, operating geometry, exposure mode, fluoroscopic time, air kerma at the reference point (RAK), and air kerma area-product. However, the presentation of this information is highly vendor specific, and many users are unaware of how to interpret this information and use it to perform a study with the minimum necessary dose. A conceptual framework for understanding the radiation dose readout during a procedure is to compare it to the dashboard of an automobile, where the rate at which radiation is being applied (the RAK rate [mGy/min]) is the dose "speed" and the cumulative amount of radiation applied (cumulative RAK [mGy]) is the dose "odometer." This analogy can be used as a starting point to improve knowledge of these parameters, including how RAK is measured, how RAK correlates with skin dose, and how parameters are displayed differently during fluoroscopy and fluorography. Awareness of these factors is critical to understanding how dose parameters translate to patient risk and the consequences of high-dose studies. With this increased awareness, physicians performing fluoroscopically guided procedures can understand how to use built-in features of the fluoroscopic equipment (pulse rate, beam filtration, and automatic exposure control) and fluoroscopic techniques (procedure planning, patient positioning, proper collimation, and magnification) to reduce patient radiation dose, thereby improving patient safety.

Radiation-induced skin injury after complex endovascular procedures.

BACKGROUND: Radiation-induced skin injury is a serious potential complication of fluoroscopically guided interventions. Transient erythema occurs at doses of 2 to 5 Gy, whereas permanent epilation, ulceration, and desquamation are expected at doses above this level. Complex endovascular procedures (CEPs), such as fenestrated endovascular aortic aneurysm repair (FEVAR), are associated with high radiation doses, yet the prevalence of radiation-induced skin injury is unknown. We hypothesized that skin injury after these exposures is likely to be underrecognized and underreported. This study examined the frequency and severity of deterministic effects and evaluated patient characteristics that might predispose to radiation injury in CEP. METHODS: CEP was defined as a procedure with a radiation dose ≥5 Gy (National Council on Radiation Protection and Measurements threshold for substantial radiation dose level [SRDL]). Radiation dose and operating factors were recorded for all CEPs performed in a hybrid room during a 30-month period. Patient medical records were retrospectively reviewed for evidence of skin injury. Patients were seen in follow-up daily until discharge and then at weeks 2 and 6, months 3 and 6, and 1 year. Phone interviews were conducted to determine the presence of any skin-related complaints. Peak skin dose (PSD) distributions were calculated for FEVARs with custom software employing input data from fluoroscopic machine logs. These calculations were validated against Gafchromic film (Ashland Inc, Covington, Ky) measurements. Dose was summed for the subset of patients with multiple procedures within 6 months of the SRDL event, consistent with Joint Commission recommendations. RESULTS: Sixty-one CEPs reached a reference air kerma (RAK) of 5 Gy (50 FEVARs, six embolizations, one thoracic endovascular aortic repair, one endovascular aneurysm repair, one carotid intervention, and two visceral interventions). The patient cohort was 79% male and had a mean body mass index of 31. The average RAK was 8 ± 2 Gy (5.0-15.9 Gy). Sixteen patients had multiple CEPs within 6 months of the SRDL event, with a mean cumulative RAK of 12 ± 3 Gy (7.0-18.4 Gy). The mean FEVAR PSD was 6.6 ± 3.6 Gy (3.7-17.8 Gy), with a mean PSD/RAK ratio of 0.78. Gafchromic film dose measurements were not statistically different from PSD estimations, with a constant of proportionality of 0.99. Three patients were lost to follow-up before their first postoperative visit. No radiation skin injuries were found. CONCLUSIONS: This study represents the largest analysis of deterministic skin injury after CEPs, and our results suggest that it is less frequent than expected and not increased in CEPs.

Surgeon education decreases radiation dose in complex endovascular procedures and improves patient safety.

OBJECTIVE: Complex endovascular procedures such as fenestrated endovascular aneurysm repair (FEVAR) are associated with higher radiation doses compared with other fluoroscopically guided interventions (FGIs). The purpose of this study was to determine whether surgeon education on radiation dose control can lead to lower reference air kerma (RAK) and peak skin dose (PSD) levels in high-dose procedures. METHODS: Radiation dose and operating factors were recorded for FGI performed in a hybrid room over a 16-month period. Cases exceeding 6 Gy RAK were investigated according to institutional policy. Information obtained from these investigations led to surgeon education focused on reducing patient dose. Points addressed included increasing table height, utilizing collimation and angulation, decreasing magnification modes, and maintaining minimal patient-to-detector distance. Procedural RAK doses and operating factors were compared 8 months pre- (group A) and 8 months post- (group B) educational intervention using analysis of variance with Tukey pairwise comparisons and t-tests. PSD distributions were calculated using custom software employing input data from fluoroscopic machine logs. RESULTS: Of 447 procedures performed, 300 FGIs had sufficient data to be included in the analysis (54% lower extremity, 11% thoracic endovascular aneurysm repair, 10% cerebral, 8% FEVAR, 7% endovascular aneurysm repair, 5% visceral, and 5% embolization). Twenty-one cases were investigated for exceeding 6 Gy RAK. FEVAR comprised 70% of the investigated cases and had a significantly higher median RAK dose compared with all other FGIs (P < .0001). There was no difference in body mass index between groups A and B; however, increasing body mass index was an indicator for increased RAK. PSD calculations were performed for the 122 procedures that focused on the thorax and abdomen (group A, 80 patients; group B, 42 patients). Surgeon education most strongly affected table height, with an average table height elevation of 10 cm per case after education (P < .0001). The dose index (PSD/RAK ratio) was used to track changes in operating practices, and it decreased from 1.14 to 0.79 after education (P < .0001). These changes resulted in an estimated 16% reduction in PSD. There was a trend toward a decrease in patient to detector distance, and the use of collimation increased from 25% to 40% (P < .001) for all cases; however, these did not result in a decrease in PSD. The number of cases that exceeded 6 Gy RAK did not change after education; however, the proportion of non-FEVAR cases that exceeded 6 Gy decreased from 40% to 20%. CONCLUSIONS: Surgeon education on the appropriate use of technical factors during FGIs improved operating practice, reduced patient radiation dose, and decreased the number of non-FEVAR cases that exceeded 6 Gy. It is essential that vascular surgeons be educated in best operating practices to lower PSD; nonetheless, FEVAR remains a high-dose procedure.

Evaluation of fluoroscopic cases qualifying as potential fluoroscopic sentinel events.

RATIONALE AND OBJECTIVES: To address the risk of radiation injury during interventional procedures, the Joint Commission has defined prolonged fluoroscopy resulting in a cumulative skin dose of 15 Gy or more to a single field as a reviewable sentinel event. The goal of this work is to present a system for identifying potential fluoroscopic sentinel events (FSE) and describing common case characteristics. MATERIALS AND METHODS: Criteria based on fluoroscopic time (FT) > 150 minutes and reference air kerma (RAK) > 6 Gy were used to identify potential sentinel events. Case information including procedure type, number of procedures, and radiation dose parameters was recorded. Peak skin dose (PSD) was calculated by a medical physicist. Values were compared between procedure types and the relationship between FT, RAK, and PSD was evaluated. RESULTS: Between 2008 and 2011, 183 events exceeding the investigation criteria were identified in three interventional categories: cardiology (54%), neuroradiology (31%), and vascular (16%). The average number of procedures/patient was 1.7 ± 0.1, with the majority (59.6%) having undergone only one procedure. Most cases could be identified using the RAK criterion alone (96.7%). Based on the PSD/RAK ratio, a threshold RAK of 7.5 Gy would effectively identify all cases that would exceed 15 Gy in PSD. CONCLUSION: Radiation delivered during interventional cases can place patients at risk of cutaneous radiation injury and potential sentinel events. Using appropriate thresholds to determine which cases require detailed investigation allows efficient utilization of department resources for identifying sentinel events.

How will you need me, how will you read me, when I'm 64 (or more!)?: volume computed tomographic scanning and information overload in the emergency department.

Computed tomographic (CT) scanning technology now employs up to 320 detector rows of 0.5-mm width and allows rapid acquisition of isotropic volume datasets over the entire body. Data from a single CT acquisition can be reconstructed into image series that would formerly have required multiple acquisitions. Small isotropic voxels permit scan parameters to be general while reconstruction algorithms remain specific to anatomy. While this results in more efficient operation in the Emergency Department, it necessitates new ways of displaying, interpreting, and archiving the information. Critical decisions include how much of the patient to scan and how to time contrast injections when imaging multiple organs. These choices must be made in light of dose considerations to the patient and the general population of patients. The technical basis of high-density CT scanning is discussed, including detector configurations and reconstruction techniques. Volumetric scanning in the Emergency Department can improve patient care but requires a change of technical habits.

Radiation exposure during standing voiding cystourethrography in women.

OBJECTIVES: To calculate the total radiation exposure and effective organ doses from standard protocol voiding cystourethrography (VCUG). METHODS: A prospective series of consecutive, non-neurogenic women underwent a standardized VCUG protocol by the same technologist using a Siemens Sireskop Fluorospot radiographic/fluoroscopic unit. Only studies that followed the protocol were included. The effective dose was calculated using a commercially available dose-modeling program (PCXMC, version 1.5) for risk assessment. RESULTS: A total of 119 studies in 118 women (mean age 60 +/- 13 years, range 30 to 93) were included. Only 15 patients (13%) were premenopausal with in situ reproductive organs. The mean number of images and fluoroscopic time per study was 12.8 +/- 1.4 (lateral images 7.5 +/- 1.3) and 35.8 +/- 11.2 seconds, respectively. The mean effective dose for a single VCUG study was calculated to be 4.3 mSv, of which 26% was from fluoroscopy (1.1 mSv). The dose to the gonads accounted for 50% of the total effective organ dose. Using whole population radiologic risk factors, the total risk detriment, cancer and hereditary, was about 3 per 10,000 patients or a 99.997% chance of no detriment incurred from the study. The genetic and malignant risks were reduced in this cohort of patients, who were older, with most (87%) having no reproductive potential. CONCLUSIONS: Using a standard protocol for adult women, a VCUG study is associated with an acceptable radiation risk.