Cumulative Radiation Exposure Research Articles

Cumulative radiation exposure and estimated lifetime cancer risk in multiple-injury adult patients undergoing repeated or multiple CTs.

To estimate the cumulative radiation exposure and lifetime attributable risk (LAR) of radiation-induced cancer from computed tomographic (CT) scanning of adult patients with multiple-injury traumas. The study comprises 328 multiple-injury adult patients who underwent diagnostic CT during 2013. Each patient's cumulative CT radiation exposure was calculated and the biological effects of ionizing radiation VII methodology was used to estimate the LAR of cancer incidence on the basis of sex and age at each exposure. The average cumulative dose per patient was 19.4mSv. One point five percent (5/328) of the patients received a cumulative effective dose ≥100mSv and 63.7% of patients received a cumulative effective dose ≤20mSv. The average LAR of cancer incidence was 0.14% or 1 in 714 patients. Only one patient had an LAR >1%, a man <30years of age. The group of major injuries [injury severity score (ISS) >15] had a statistically significantly greater accumulative effective dose and slightly greater LAR than the group of minor injuries (ISS ≤15). More than half of the multiple-injury trauma patients were classified as low risk cumulative effective dose (≤20mSv) and almost all patients had a low LAR risk of cancer incidence from CT studies. Patients who were at the highest risk of cancer from CT scans were those aged under 30years who had multiple or repeated scans, particularly in the trunk.

Estimation of individual cumulative ultraviolet exposure using a geographically-adjusted, openly-accessible tool.

BackgroundEstimates of an individual’s cumulative ultraviolet (UV) radiation exposure can be useful since ultraviolet radiation exposure increases skin cancer risk, but a comprehensive tool that is practical for use in the clinic does not currently exist.The objective of this study is to develop a geographically-adjusted tool to systematically estimate an individual’s self-reported cumulative UV radiation exposure, investigate the association of these estimates with skin cancer diagnosis, and assess test reliability.MethodsA 12-item online questionnaire from validated survey items for UV exposure and skin cancer was administered to online volunteers across the United States and results cross-referenced with UV radiation indices. Cumulative UV exposure scores (CUES) were calculated and correlated with personal history of skin cancer in a case–control design. Reliability was assessed in a separate convenience sample.Results1,118 responses were included in the overall sample; the mean age of respondents was 46 (standard deviation 15, range 18 – 81) and 150 (13 %) reported a history of skin cancer. In bivariate analysis of 1:2 age-matched cases (n = 149) and controls (n = 298), skin cancer cases were associated with (1) greater CUES prior to first skin cancer diagnosis than controls without skin cancer history (242,074 vs. 205,379, p = 0.003) and (2) less engagement in UV protective behaviors (p < 0.01). In a multivariate analysis of age-matched data, individuals with CUES in the lowest quartile were less likely to develop skin cancer compared to those in the highest quartile. In reliability testing among 19 volunteers, the 2-week intra-class correlation coefficient for CUES was 0.94. We have provided the programming code for this tool as well as the tool itself via open access.ConclusionsCUES is a useable and comprehensive tool to better estimate lifetime ultraviolet exposure, so that individuals with higher levels of exposure may be identified for counseling on photo-protective measures.Electronic supplementary materialThe online version of this article (doi:10.1186/s12895-016-0038-1) contains supplementary material, which is available to authorized users.

Cumulative radiation exposure and associated cancer risk estimates for scoliosis patients: Impact of repetitive full spine radiography

ObjectiveTo quantitatively evaluate the cumulative effective dose and associated cancer risk for scoliotic patients undergoing repetitive full spine radiography during their diagnosis and follow up periods. MethodsOrgan absorbed doses of full spine exposed scoliotic patients at different age were computer simulated with the use of PCXMC software. Gender specific effective dose was then calculated with the ICRP-103 approach. Values of lifetime attributable cancer risk for patients exposed at different age were calculated for both patient genders and for Asian and Western population. Mathematical fitting for effective dose and for lifetime attributable cancer risk, as function of exposed age, was analytically obtained to quantitatively estimate patient cumulated effective dose and cancer risk. ResultsThe cumulative effective dose of full spine radiography with posteroanterior and lateral projection for patients exposed annually at age between 5 and 30 years using digital radiography system was calculated as 15mSv. The corresponding cumulative lifetime attributable cancer risk for Asian and Western population was calculated as 0.08–0.17%. Female scoliotic patients would be at a statistically significant higher cumulated cancer risk than male patients under the same full spine radiography protocol. ConclusionWe demonstrate the use of computer simulation and analytic formula to quantitatively obtain the cumulated effective dose and cancer risk at any age of exposure, both of which are valuable information to medical personnel and patients’ parents concern about radiation safety in repetitive full spine radiography.

Cumulative radiation exposure from diagnostic imaging in intensive care unit patients.

To quantify cumulative effective dose of intensive care unit (ICU) patients attributable to diagnostic imaging. This was a prospective, interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center. Demographic and clinical data including age, gender, date of ICU admission, primary reason for ICU admission, APACHE II score, length of stay, number of days intubated, date of death or discharge, and re-admission data was collected on all patients admitted over a 1-year period. The overall radiation exposure was quantified by the cumulative effective radiation dose (CED) in millisieverts (mSv) and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board. Pediatric patients were selected for subgroup-analysis. A total of 2737 studies were performed in 421 patients. The total CED was 1704 mSv with a median CED of 1.5 mSv (IQR 0.04-6.6 mSv). Total CED in pediatric patients was 74.6 mSv with a median CED of 0.07 mSv (IQR 0.01-4.7 mSv). Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED. Computed tomography (CT) accounted for 16% of all studies performed and contributed 97% of total CED. Trauma patients received a statistically significant higher dose [median CED 7.7 mSv (IQR 3.5-13.8 mSv)] than medical [median CED 1.4 mSv (IQR 0.05-5.4 mSv)] and surgical [median CED 1.6 mSv (IQR 0.04-7.5 mSv)] patients. Length of stay in ICU [OR = 1.12 (95%CI: 1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mSv. Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs. CED should be minimized where feasible, especially in young patients.

Reduction of Fluoroscopic Exposure Using a New Fluoroscopy Integrating Technology in a 3D-Mapping System During Pulmonary Vein Isolation With a Circular Multipolar Irrigated Catheter.

Pulmonary vein isolation (PVI) is a cornerstone therapy in patients with atrial fibrillation (AF). With increasing numbers of PVI procedures, demand arises to reduce the cumulative fluoroscopic radiation exposure for both the physician and the patient. New technologies are emerging to address this issue. Here, we report our first experiences with a new fluoroscopy integrating technology in addition to a current 3D-mapping system. The new fluoroscopy integrating system (FIS) with 3D-mapping was used prospectively in 15 patients with AF. Control PVI cases (n = 37) were collected retrospectively as a complete series. Total procedure time (skin to skin), fluoroscopic time, and dose-area-product (DAP) data were analyzed. All PVI procedures were performed by one experienced physician using a commercially available circular multipolar irrigated ablation catheter. All PVI procedures were successfully undertaken without major complications. Baseline characteristics of the two groups showed no significant differences. In the group using the FIS, the fluoroscopic time and DAP were significantly reduced from 571 ± 187 seconds versus 1011 ± 527 seconds (P = 0.0029) and 4342 ± 2073 cGycm(2) versus 6208 ± 3314 cGycm(2) (P = 0.049), respectively. Mean procedure time was not significantly affected and was 114 ± 31 minutes versus 104 ± 24 minutes (P = 0.23) by the FIS.The use of the new FIS with the current 3D-mapping system enables a significant reduction of the total fluoroscopy time and DAP compared to the previous combination of 3D-mapping system plus normal fluoroscopy during PVI utilizing a circular multipolar irrigated ablation catheter. However, the concomitant total procedure time is not affected. Thus, the new system reduces the radiation exposure for both the physicians and patients.

Computed tomography dose optimisation in cystic fibrosis: A review.

Cystic fibrosis (CF) is the most common autosomal recessive disease of the Caucasian population worldwide, with respiratory disease remaining the most relevant source of morbidity and mortality. Computed tomography (CT) is frequently used for monitoring disease complications and progression. Over the last fifteen years there has been a six-fold increase in the use of CT, which has lead to a growing concern in relation to cumulative radiation exposure. The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality, but fulfil the requirements of a diagnostic quality CT. Dose-optimisation, particularly in CT, is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 mSv, a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation. This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.

Effects of chronic low-dose exposure to ionizing radiation on physician microvascular structure revealed by nail fold capillaroscopy.

The aim of this study was to assess the long-term asymptomatic effects of low-dose radiation on microvascular structure among interventional physicians, whose hands are exposed to ionizing radiation during daily practice. The study, approved by the national ethics committee, included 186 radiation-exposed (surgeons, cardiologists, radiologists) and 35 unexposed physicians, all of whom had provided written consent. The subjects completed a questionnaire describing their current and past daily practice, from which tentative estimates of current and cumulative radiation exposure estimates were computed. Subject dermal microcirculation state was assessed by capillaroscopy of the nail fold of eight fingers (thumbs excluded) based on photographs. Two quantitative scores characterizing extravasation and morphological abnormalities based on seven semiquantitative indices were obtained from post hoc coding of the photographs by five capillaroscopists. These evaluations were randomized and blind to the exposure. The effect of the radiation exposure on both abnormality scores was modelled using multilevel proportional odds regression adjusted for potential confounders. The proportion of physicians for which the most frequent act is close to the radiation source was highest among surgeons, but with fewer weekly acts. The median duration of exposure was highest among radiologists and cardiologists. No exposure effect could be detected on the extravasation score. The morphological anomaly score increased significantly with duration of exposure and estimated cumulative exposure among surgeons and interventional radiologists, unlike cardiologists among whom no effect could be detected. It is concluded that the shown effects of chronic low-dose exposure to ionizing radiation on physician microvascular structure reveal the importance of increased exposure monitoring and prevention.

Reply

We thank for these pleasant comments and are happy that the idea of dose-reduced computed tomography (CT) and CT-based compositional analysis of urinary stones is of importance for the editors of Urology. 1 Slater R.C. Jackman S.V. Focused dual-energy CT maintains diagnostic and compositional accuracy for urolithiasis using ultralow-dose noncontrast CT [Editorial Comment]. Urology. 2015; 86: 1097-1103 Abstract Full Text Full Text PDF PubMed Google Scholar New developments of imaging modalities have influenced different fields of medicine sustainably, including urolithiasis management. In many urology departments, CT has replaced radiography of kidney, ureter, and bladder as well as intravenous pyelogram almost completely in primary evaluation of renal colic patients. Over the years, the CT technology could be improved significantly due to bringing innovations such as dose-reduced protocols, shorter examination times, high-definition imaging, and in situ compositional analysis of the targeted stones. Our study was performed on 61 patients revealing high sensitivity and specificity in detection of clinically relevant uric acid- and non–uric acid-containing fragments. 1.We believe that similar results for sensitivity and specificity rates can be reproduced in other institutions using the highly dose-reduced noncontrast CT (NCCT) protocol including compositional analysis. The methods applied have been described in detail. We would be very pleased if other groups, wishing to decrease radiation exposure of urolithiasis patients, would join our efforts and work on related topics in collaborative projects. 2.In the German health care system, the radiologist is involved in the evaluation process of the CT results and decision making whether the dual-energy (DE) technology is applied. Because of this organization model, a significant decrease in radiation can be achieved. We are aware that this is not the case in many countries worldwide. As a consequence, this might be the crucial limitation in the acceptance of this approach in differently organized health care systems, where CT scans are not interpreted directly by a radiologist and the image acquisition is performed independently by excellently trained radiology technicians. We believe that diagnosing urolithiasis might be feasible for such personnel after professional training. Furthermore, these measures would make radiology technicians more familiar with the DE technology and novel CT protocols. In our opinion, the decision whether to use a targeted DE mode scan can also be taken by a radiology technician. In countries where legal issues prohibit such course of action, efforts should be undertaken to rearrange the workflow in radiology departments and establish a timely involvement of a radiologist in the CT scan evaluation in stone patients. 3.Conventional NCCT might provide reliable information regarding stone composition based on Hounsfield unit characteristics of a visualized fragment. However, this might not be accurate in many cases and leads to substantially higher patient radiation exposure. To our knowledge, it is not possible to determine the stone composition correctly while performing an NCCT according to an ultralow energy dose protocol. Therefore, an additional DE technology–based analysis has to be implemented. Applying our novel protocol, low-dose NCCT plus DE mode–based analysis of stone composition results in significantly lower cumulative radiation exposure and provides superior results at the same time. “Primum non nocere” (first, do no harm): We believe that this justifies potentially higher financial expenses and time. Editorial CommentUrologyVol. 86Issue 6PreviewThe authors provide a timely demonstration of an innovative low-dose noncontrast computed tomography (NCCT) plus dual-energy CT (DECT) protocol in reducing radiation exposure in the evaluation of patients presenting with urolithiasis while simultaneously maintaining accurate compositional analysis of such calculi.1 This protocol calls for patients to undergo an ultralow-dose NCCT followed by a focused dose-reduced noncontrast DECT. It was evaluated in 61 patients whose stones were available for chemical analysis. Full-Text PDF

Contrast-enhanced ultrasound after endovascular aortic repair-current status and future perspectives.

An increasing number of patients with abdominal aortic aneurysms (AAAs) are undergoing endovascular aortic repair (EVAR) instead of open surgery. These patients require lifelong surveillance, and the follow-up imaging modality of choice has been traditionally computed tomography angiography (CTA). Repetitive CTA imaging is associated with cumulative radiation exposure and requires the administration of multiple doses of nephrotoxic contrast agents. Contrast-enhanced ultrasound (CEUS) has emerged as an alternative strategy in the follow-up of patients with EVAR and demonstrates high sensitivity and specificity for detection of endoleaks. In fact, a series of studies have shown that CEUS is at least performing equal to computed tomography for the detection and classification of endoleaks. This article summarizes current evidence of CEUS after EVAR and demonstrates its usefulness via various patient cases.

Minimizing Radiation Exposure During ERCP by Avoiding Live or Continuous Fluoroscopy.

The aim of this study was to assess the cumulative radiation exposure incurred by patients when using single-frame fluoroscopy. Single-frame fluoroscopy is a technique that can be used instead of pulsed fluoroscopy or continuous live fluoroscopy to minimize radiation exposure during endoscopic retrograde cholangiopancreatography (ERCP). We retrospectively reviewed ERCPs performed at our academic medical center. We recorded fluoroscopy time (FT, minutes), total radiation dose (mGy), dose area product (DAP, Gy cm²), and effective dose (ED, mSv). ERCP degree of difficulty was graded based on procedure complexity level. There were 400 ERCP procedures performed on 210 patients, 32 ERCPs were unsuccessful. The mean FT for all procedures was 1.57 minutes (median, 1.2 min); the mean FT for complexity score 1 procedures (0.78 min) was significantly shorter than for all other procedures (P<0.0001). The mean total radiation dose delivered for all procedures was 23.02 mGy (median, 14.95 mGy). The total radiation dose for complexity score 1 procedures (13.15 mGy) was significantly lower than for all other complexity scores (P<0.0001). The mean total DAP was 3.62 Gy cm² and the mean ED was 0.94 mSv. Procedure complexity score 1 DAP (2.1 Gy cm²) and ED (0.55 mSv) were significantly lower than for all other procedures (P<0.0001 for both). There was no statistically significant difference in these parameters when comparing successful and unsuccessful procedures. Successful ERCP can be performed using single-frame fluoroscopy only. Our results demonstrate lower radiation exposure using this technique than what is reported in the literature.

Correlation of Cumulative Diagnostic Radiation Exposure With Increasing Lemann Index: The Need for Increased Provider Vigilance in Certain Crohnʼs Disease Sub-groups

Introduction: Recurrent exposure to diagnostic ionizing radiation and the resultant increase in lifetime risk of cancer is a well-known concern in Crohn's disease (CD) patients. Lemann Index (LI) is a new metric that quantifies bowel damage mediated by CD. Stratification of CD patients based on change in LI over time is a novel approach to defining patient subgroups. We aimed to evaluate ionizing radiation exposure secondary to diagnostic testing, across different CD trajectories in a cohort stratified by change in LI. Methods: CD patients with 5 year(y) follow-up from a registry maintained at a tertiary center were included. LI was calculated using a computerized model from first (LI1) and last (LI2) clinical encounters. Patients were stratified based on change in index (LI2-LI1) or the delta LI (DLI) as showing improvement, no change or deterioration. Subgroups were created by dichotomizing mean improvement, mean deterioration and no change and used for association analysis with the cumulative effective dose (CED) of radiation received during 5y. Results: A total of 363 CD patients with 5y complete follow-up formed the study cohort [median age 43y (IQR: 33.3-55); 57% female; median disease duration 12y (IQR: 3-19), overall surgical exposure 69.7%]. Median (IQR) LI1, LI2 and DLI were 8 (0-54), 9 (0-75) and 0 (-22 - 47) respectively. Patients were stratified based on DLI into subgroups (A: DLI < -2.98; B: DLI -2.98 - 0; C: DLI 0, D: DLI 0 - 7.75; E: DLI >7.75). The study cohort underwent a total of 1414 diagnostic tests associated with radiation exposure (including abdominal radiographs, computed tomography [CT] scans and barium studies) with a median CED of 20mSv/person and median yearly radiation exposure of 4mSv/person/y. Use of CT scans accounted for 93.5% of CED. There was a significant difference in the number of tests and CED across the subgroups (p < 0.001), with highest and least median CED noted in groups E and C respectively [Table 1]. CED showed significant correlation with DLI (r = 0.35; p < 0.001).Table 1: Differences in cumulative effective dose of radiation received amongst Delta Lémann Index based five year trajectories of Crohn's diseaseConclusion: Identifiable subsets of patients with Crohn's disease are at risk of exposure to significant amounts of diagnostic radiation. When compared with natural background radiation exposure (3.1mSv/y), patients with rapidly worsening LI are exposed to 4 times higher dose of ionizing radiation each year. Clinicians must remain vigilant of the risk of cumulative radiation, particularly in patients with aggressive disease.

Three-dimensional accurate detection of lung emphysema in rats using ultra-short and zero echo time MRI.

Emphysema is a life-threatening pathology that causes irreversible destruction of alveolar walls. In vivo imaging techniques play a fundamental role in the early non-invasive pre-clinical and clinical detection and longitudinal follow-up of this pathology. In the present study, we aimed to evaluate the feasibility of using high resolution radial three-dimensional (3D) zero echo time (ZTE) and 3D ultra-short echo time (UTE) MRI to accurately detect lung pathomorphological changes in a rodent model of emphysema.Porcine pancreas elastase (PPE) was intratracheally administered to the rats to produce the emphysematous changes. 3D ZTE MRI, low and high definition 3D UTE MRI and micro-computed tomography images were acquired 4 weeks after the PPE challenge. Signal-to-noise ratios (SNRs) were measured in PPE-treated and control rats. T2* values were computed from low definition 3D UTE MRI. Histomorphometric measurements were made after euthanizing the animals. Both ZTE and UTE MR images showed a significant decrease in the SNR measured in PPE-treated lungs compared with controls, due to the pathomorphological changes taking place in the challenged lungs. A significant decrease in T2* values in PPE-challenged animals compared with controls was measured using UTE MRI. Histomorphometric measurements showed a significant increase in the mean linear intercept in PPE-treated lungs. UTE yielded significantly higher SNR compared with ZTE (14% and 30% higher in PPE-treated and non-PPE-treated lungs, respectively).This study showed that optimized 3D radial UTE and ZTE MRI can provide lung images of excellent quality, with high isotropic spatial resolution (400 µm) and SNR in parenchymal tissue (>25) and negligible motion artifacts in freely breathing animals. These techniques were shown to be useful non-invasive instruments to accurately and reliably detect the pathomorphological alterations taking place in emphysematous lungs, without incurring the risks of cumulative radiation exposure typical of micro-computed tomography.

Occupational ionising radiation and risk of basal cell carcinoma in US radiologic technologists (1983–2005)

ObjectiveTo determine risk for incident basal cell carcinoma from cumulative low-dose ionising radiation in the US radiologic technologist cohort.MethodsWe analysed 65 719 Caucasian technologists who were cancer-free at baseline (1983–1989...

In vivo X-Ray Phase Imaging

In vivo X-Ray Phase Imaging

Patterns of diagnostic imaging and associated radiation exposure among long-term survivors of young adult cancer: a population-based cohort study

BackgroundSurvivors of young adult malignancies are at risk of accumulated exposures to radiation from repetitive diagnostic imaging. We designed a population-based cohort study to describe patterns of diagnostic imaging and cumulative diagnostic radiation exposure among survivors of young adult cancer during a survivorship time period where surveillance imaging is not typically warranted.MethodsYoung adults aged 20–44 diagnosed with invasive malignancy in Ontario from 1992–1999 who lived at least 5 years from diagnosis were identified using the Ontario Cancer Registry and matched 5 to 1 to randomly selected cancer-free persons. We determined receipt of 5 modalities of diagnostic imaging and associated radiation dose received by survivors and controls from years 5–15 after diagnosis or matched referent date through administrative data. Matched pairs were censored six months prior to evidence of recurrence.Results20,911 survivors and 104,524 controls had a median of 13.5 years observation. Survivors received all modalities of diagnostic imaging at significantly higher rates than controls. Survivors received CT at a 3.49-fold higher rate (95 % Confidence Interval [CI]:3.37, 3.62) than controls in years 5 to 15 after diagnosis. Survivors received a mean radiation dose of 26 miliSieverts solely from diagnostic imaging in the same time period, a 4.57-fold higher dose than matched controls (95 % CI: 4.39, 4.81).ConclusionsLong-term survivors of young adult cancer have a markedly higher rate of diagnostic imaging over time than matched controls, imaging associated with substantial radiation exposure, during a time period when surveillance is not routinely recommended.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1578-1) contains supplementary material, which is available to authorized users.

Total Effective Radiation Dose Attributable to Medical Imaging in Patients With Acute Chest Pain: A Single-Center Comparison Study Between Dual-Source Coronary CT Angiography and Usual Care

Introduction: Coronary CT angiography (CCTA) can safely disposition low to intermediate risk chest pain (CP); however, there is conflicting data with respect to cumulative radiation exposure when compared with usual care over short follow-up intervals. Objectives: We report the effective radiation dose from index and downstream testing in low to intermediate risk symptomatic patients evaluated for chest pain in the ED with either CCTA or usual care to define various sources of patient radiation dose and quantify effective dose over a year and a half of follow-up. Patients and Methods: We evaluated radiation exposure from initial and downstream testing in a prospectively collected, matched cohort evaluated for CP in the emergency department (ED) with either CCTA compared with usual care over a median follow-up of 19.6 months. Effective radiation dose was calculated using published conversion factors. Results: Prospective, ECG-triggered acquisition using a 128-slice dual-source multidetector computed tomography (DSCT) scanner was performed in 92.9% of scans with a median effective dose from CCTA of 6.8 mSv (IQR 5.2, 9.1 mSv). CCTA cohort patients were more likely to undergo cardiac testing with exposure to radiation (P < 0.001); however, the median effective dose in patients exposed to radiation from cardiac testing was significantly lower in the CCTA cohort (7.1 mSv vs. 11.8 mSv, P < 0.001). Fewer patients in the CCTA cohort had additional non-cardiac thoracic imaging radiation exposure (40.8%) compared with usual care (92.8%). Total radiation exposure from any source was similar between the CCTA and usual care groups (100% vs 98.4%, P = 0.087), as was median total effective radiation dose (P = 0.105). Upfront CCTA was not associated with higher rates of incidental non-cardiac findings. Conclusions: Initial evaluation of acute chest pain in the ED with CCTA was not associated with an increase in total radiation exposure over a follow-up period of 19 months. CCTA offers a more comprehensive evaluation of multiple thoracic organ systems leading to reduced radiation exposure from non-cardiac thoracic testing and no increase in incidental imaging findings. This may represent an added benefit in this population of patients presenting acutely.

Ionizing radiation exposure as a result of diagnostic imaging in patients with lymphoma

Survival rates among patients with lymphoma continue to improve. Strategies aimed at reducing potential treatment-related toxicity are increasingly prioritized. While radiological procedures play an important role, ionizing radiation exposure has been linked to an increased risk of malignancy, particularly among individuals whose cumulative radiation exposure exceeds a specific threshold (75 millisieverts). Within this retrospective study, the cumulative radiation exposure dose was quantified for 486 consecutive patients with lymphoma. The median estimated total cumulative effective dose (CED) of ionizing radiation per subject was 69 mSv (42-118). However, younger patients (under 40 years) had a median CED of 89 mSv (55-124). This study highlights the considerable radiation exposure occurring among patients with lymphoma as a result of diagnostic imaging. To limit the risk of secondary carcinogenesis, consideration should be given to monitoring cumulative radiation exposure in individual patients as well as considering imaging modalities, which do not impart an ionizing radiation dose.

The Utility of Computed Tomography in Shunted Patients with Idiopathic Intracranial Hypertension Presenting to the Emergency Department

Shunted patients with idiopathic intracranial hypertension (IIH) often present to the emergency department (ED) for symptoms related to their disease. Although brain imaging with computed tomography (CT) is often performed, particularly in the current medicolegal environment, its utility during these ED visits is unclear. The ED visits of all shunted adult patients with IIH from 2003-2015 were retrospectively reviewed. ED visits not related to IIH were excluded from our study. Thirty-one patients visited the ED 171 times for IIH symptoms. Five patients had greater than 10 ED visits. Twenty-five (81%) patients had 131 visits involving a CT scan, while six (19%) patients were not scanned. The majority of scans (n = 126, 96%) showed no change; five (4%) scans detected new noncritical pathologies. On the basis of CT findings alone, treatment changes occurred in three (2.3%) instances. Of the 131 visits with a CT scan, twenty-five (19%) visits resulted in management changes; of the 40 ED visits without a CT scan, four (10%) visits resulted in a management change (P = 0.23). In our cohort, CT imaging rarely showed a change in pathology or affected the management of patients with IIH. There was no difference in the rate of management changes between those patients who underwent a CT scan and those who did not. Given the risk of cumulative radiation exposure and cost of CT scans, CT imaging should be used when there is concern for visual dysfunction and the utility of CT imaging in the ED for the workup of other symptoms related to IIH must be explored further.

Surgeon Radiation Exposure in Hip Arthroscopy

Objectives:Hip arthroscopy is an established field within orthopaedic surgery. The majority of the procedures involve repairs of the acetabular labrum and arthroscopic treatment of femoroacetabular impingement (FAI). The procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended during these procedures, and radiation exposure to the surgeon, staff, and patient remains a valid concern. The purpose of this study is to measure radiation exposure to the surgeon during hip arthroscopy and determine if this exposure remains below recommended annual occupational radiation exposure thresholds recommended by the International Committee on Radiological Protection (IRCP).Methods:Prospectively, radiation exposure was measured for a single surgeon at a single outpatient facility for all hip arthroscopic procedures over a three-year period. A radiation dosimeter was worn outside of the surgeon's chest on the lead apron. Standard pre-operative and intra-operative imaging was used for all patients. Radiation readings were prospectively measured for deep dose equivalent (DDE), lens dose equivalent (LDE), and shallow dose equivalent (SDE). The cumulative radiation exposure was tabulated in millirem (mrem), converted to milli-Sieverts (mSv) (standard measurement used by the IRCP) and then the per-patient exposure calculated as well as annual exposure for 100 hip arthroscopies per year.Results:Between July 2011 and July 2014, 209 patients underwent a total of 280 hip arthroscopy procedures at a single facility by a single surgeon. There were 90 labral repairs, 83 femoroplasties, 26 acetabuloplasties, 66 labral debridements, 8 trochanteric bursectomies, and 7 iliopsoas releases. The cumulative DDE was 183 mrem (1.83 mSv), LDE 183 mrem (1.83 mSv), and SDE 176 mrem (1.76 mSv). The calculated per patient exposure for the surgeon was DDE 0.875 mrem (0.00875 mSv), LDE 0.875 mrem (0.00875 mSv), and SDE 0.842 mrem (0.00843 mSv). Calculated annual exposure for a surgeon performing 100 hip arthroscopies per year are DDE 8.75 mrem (0.0875 mSv), LDE 8.75 mrem (0.0875 mSv), and SDE 8.43 mrem (0.0842 mSv).Conclusion:Hip arthroscopy & hip preservation procedures are being performed with increasing frequency annually. Fluoroscopic guidance is recommended for safe entrance into the central compartment and during various parts of the procedures. Radiation exposure to the surgeon, staff, and patient is a valid concern. The IRCP sets recommended annual safety thresholds for occupational radiation exposure. Current annual safety thresholds are 50,000 mrem (500 mSv) to the hands, 50,000 mrem (500 mSv) to the skin, hands & feet, 15,000 mrem (150 mSv) to the eye, and 30,000 mrem (300 mSv) to the thyroid of healthcare workers. Our study shows surgeon radiation exposure below the annual safety thresholds recommended by the IRCP for 100 cases per year. For surgeons performing more than 100 hip arthroscopic procedures annually, the exposure will be higher. Appropriate safety equipment such as lead aprons, thyroid shields, and leaded glasses are still recommended, especially for high volume hip arthroscopists.

Focal Arrhythmia Ablation Determined by High-Resolution Noninvasive Maps: Multicenter Feasibility Study.

A noninvasive 3D mapping technique (ECVUE™, CardioInsight Inc., Cleveland) maps the origin and mechanisms of various arrhythmias without catheterizing the heart. Thirty-three patients (3 centers, mean 45.0 ± 14.6 years,) with symptomatic premature ventricular complexes (24 PVCs), focal atrial tachycardias (2 ATs), and manifest accessory pathways (7 WPW syndromes) were prospectively explored using 3D, noninvasive bedside electrocardiomapping. The location of origin of the focal arrhythmia was first determined using noninvasive mapping. Subsequently, a stimulus artifact was delivered at this site to confirm and evaluate the precise location of the mapped focal origin. The procedural parameters and clinical efficacy were studied. Ablation was successful in 32/33 (97%) patients (PVCs: 13 right, 10 left, 1 septal; WPW: 3 left, 3 right; ATs: 2 left) without complications. The time from catheterization to permanent arrhythmia elimination/termination, RF duration, skin-to-skin procedural duration, and fluoroscopic exposure were median 16, 3.98, 71, and 11.9 minutes (for n = 29), respectively. At mean 24.7 ± 3.7 months of follow-up, 31 patients remain arrhythmia-free after a single procedure. One patient (right WPW syndrome) required repeat ablation 1 month later. One patient had recurrence of PVCs and is now deceased. The cumulative radiation (CT scan and fluoroscopy) exposure was median 7.57 mSv. ECVUE(TM) is a noninvasive tool allowing rapid preprocedural localization of focal arrhythmia and enables the electrophysiologist with highly specific information to direct RF delivery at the source of the arrhythmia with minimal intracardiac mapping.