Pause and pulse: ten steps that help manage radiation dose during pediatric fluoroscopy

Immobilization during infant fluoroscopy: Pros and cons

This article explores the practice of immobilization during fluoroscopy procedures for infants, discussing its advantages and disadvantages. The authors examine contrasting policies and thoughts on immobilization across different medical institutions. While some advocate for its routine use to minimize patient motion, enhance imaging quality, and decrease radiation exposure, others question its necessity and raise concerns about patient consent and parental distress. Ethical dilemmas are also discussed regarding patient autonomy and psychological impact on families. The authors advocate for a balanced approach, recognizing the utility of immobilization in certain clinical scenarios while still emphasizing patient-centered care. Ultimately, the article underscores the importance of institutional policies that prioritize both patient safety and ethical principles in pediatric radiology practices.

Influence of frame rate in detecting oropharyngeal aspiration in paediatric videofluoroscopic swallow studies - An observational study

OBJECTIVES

The videofluoroscopic swallow study (VFSS), currently the gold standard for assessing aspiration in children, incurs radiation. Adhering to the ALARA principle is crucial in minimising radiation dose whilst obtaining accurate diagnostic information in children. International adult VFSS guidelines recommend a capture rate of 30 frames per second (fps). Higher capture rates increase radiation yet there is limited evidence on best practice VFSS capture rates in children, particularly on thin fluid consistency-the fastest viscosity with the highest potential for missed aspiration on slower capture rates. We aimed to determine if image acquisition at 30fps versus 15fps alters the accuracy of detecting aspiration when assessing thin fluids during paediatric VFSS.

MATERIALS & METHODS

Seventeen speech language pathologists (SLPs) blindly rated a total of 2,356 swallow loops for the presence/absence of aspiration from VFSS recordings of 13 infants/children drinking thin fluids. 76 swallow loops were randomly presented at 15 versus 30fps, on two occasions. Area under receiver operating curve (aROCs) was used to compare the accuracy of aspiration ratings at 15 versus 30fps compared to a comparison set. The intraclass correlation coefficient (ICC) was used to examine rater reliability.

RESULTS

Accuracy for detecting aspiration was near-identical at 15fps (aROC:0.97; 95%CI:0.96-0.97) and 30fps (0.96; 95%CI 0.96-0.97). Good inter-rater (ICC:0.82; 95%CI:0.72-0.89) and intra-rater reliability among the raters (ICC:0.89; 95%CI:0.82-0.93) was found.

CONCLUSION

Using 15fps in paediatric VFSS when assessing thin fluid consistency aspiration provides a similar detection rate to using 30fps. As 15fps would have a lower radiation dose than 30fps, we recommend using 15fps when undertaking VFSS in children.

CLINICAL RELEVANCE STATEMENT

Adhering to the ALARA principles, a capture rate of 15fps should be used in paediatric VFSS for assessment on thin fluids.

[Voiding cystourethrography : Indications, fluoroscopy technique and radiation protection]

BACKGROUND

Voiding cystourethrography continues to be the gold standard in the diagnostics of a wide range of diseases of the urinary tract in children.

MATERIAL AND METHODS

Indications, implementation of voiding cystourethrography in terms of preparation, materials used, dealing with the child and the parents as well as the standardized examination technique are presented. In particular, the technical aspects of fluoroscopy devices and criteria for good image quality are discussed. Case studies are used to illustrate the problems of frequent urological diseases.

DISCUSSION

The three standard examinations for the detection of vesicoureteral reflux (VUR), radionuclide cystography, contrast-enhanced voiding urosonography and voiding cystourethrography are compared. Their potential for detecting VUR and additional urological pathologies is discussed in detail. Furthermore, the optimized examination technique of voiding cystourethrography is presented. The applicability of the current dose reference values of the German Federal Office for Radiation Protection (BfS) in the daily routine is discussed and the feasibility of the dose reference values is explained.

Foley catheter technique for the extraction of coins lodged in the upper esophagus of children

INTRODUCTION

Coins are the most commonly ingested foreign bodies in children. They usually become lodged in the upper oesophagus and should be managed immediately. The aim of the present study was to evaluate the characteristics and outcomes of patients with coins lodged in the upper oesophagus, who underwent coin removal using a silicone Foley balloon catheter without fluoroscopy or anaesthesia and evaluate the safety of the procedure.

MATERIALS AND METHODS

Patients who were admitted from January 2007 to December 2022 for coins lodged in the oesophagus and extracted with silicone Foley balloon catheter without anestehesia were evaluated retrospectively. We focused on the patient characteristics and clinical presentations, and the treatment safety, efficacy, and outcomes.

RESULTS

773 patients (416 male, 357 female), with a mean age of 3.5 years (range 6 months to 16 years), who ingested coin and extracted with Foley catether is included. The majority of patients (n = 728, 94.17%) were successfully managed by silicone Foley balloon catheter extraction. Our overall success was 94.17%, with 88.30% of coins retrieved and 5.9% pushed into the stomach. Patients who were successfully treated with Foley catheter were discharged on the same day except for 7 (0.90%) who had minimal bleeding. Only 45 (5.82%) patients required oesophagoscopy in the operating room and these patients were kept overnight for clinical follow-up, without any further interventions.

CONCLUSION

A Foley balloon catheter can be used to safely and effectively remove coins that are lodged in the upper oesophagus avoiding the risk of general anesthesia.

Comparison of the different imaging modalities used to image pediatric oncology patients: A COG diagnostic imaging committee/SPR oncology committee white paper

Diagnostic imaging is essential in the diagnosis and management, including surveillance, of known or suspected cancer in children. The independent and combined roles of the various modalities, consisting of radiography, fluoroscopy, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine (NM), are both prescribed through protocols but also function in caring for complications that may occur during or subsequent to treatment such as infection, bleeding, or organ compromise. Use of a specific imaging modality may be based on situational circumstances such as a brain CT or MR for a new onset seizure, chest CT for respiratory signs or symptoms, or US for gross hematuria. However, in many situations, there are competing choices that do not easily lend themselves to a formulaic approach as options; these situations depend on the contributions of a variety of factors based on a combination of the clinical scenario and the strengths and limitations of the imaging modalities. Therefore, an improved understanding of the potential influence of the imaging decision pathways in pediatric cancer care can come from comparison among the individual diagnostic imaging modalities. The purpose of the following material to is to provide such a comparison. To do this, pediatric imaging content experts for the individual modalities of radiography and fluoroscopy, US, CT, MRI, and NM will discuss the individual modality strengths and limitations.

A Tutorial on Diagnostic Benefit and Radiation Risk in Videofluoroscopic Swallowing Studies

The videofluoroscopic swallowing study (VFSS) is a key tool in assessing swallowing function. As with any diagnostic procedure, the probable benefits of the study must be weighed against possible risks. The probable benefit of VFSS is an accurate assessment of swallowing function, enabling patient management decisions potentially leading to improved patient health status and quality of life. A possible (though highly unlikely) risk in VFSS is carcinogenesis, arising from the use of ionizing radiation. Clinicians performing videofluoroscopic swallowing studies should be familiar with both sides of the risk benefit equation in order to determine whether the study is medically justified. The intent of this article is to provide the necessary background for conversations about benefit and risk in videofluoroscopic swallowing studies.

Single step track dilatation for percutaneous nephrolithotomy in children

Introduction and objectives

Data on the use of single step dilatation technique during pediatric percutaneous nephrolithotomy (PCNL) in the literature is sparse. In this prospective randomized study, we aimed to compare the safety, efficacy, and perioperative complications of single step versus serial tract dilatation using Alken metal telescopic dilators during pediatric PCNL.

Methods

Patients undergoing PCNL were randomized into two groups according to the dilatation technique used. In group A, Alken telescopic serial metal dilatation was utilized, and in group B, single step dilatation was performed. Inclusion criteria included children < 18 years with stone burden from 2 to 4 cm, located in the renal pelvis ± one calyx, who were candidates for PCNL.

The primary outcomes were access time and complications’ rate. The secondary outcomes were dilatation fluoroscopy time, operative duration, stone free rate, postoperative hospital stay, hemoglobin deficit, and need for blood transfusion. Both outcomes were evaluated and compared between both treatment groups.

Results

A total of 70 patients were randomized into group A (35 patients) and group B (35 patients). Access was successfully obtained in all procedures. All the procedures were performed through a single tract.

Access time and dilatation fluoroscopy time were shorter in group B (statistically significant). Patients in group A had higher rate of complications (statistically significant). Intraoperative bleeding requiring blood transfusion was less in single track dilatation than serial metal track dilatation.

Conclusions

Compared to serial metal track dilatation, single step dilatation showed comparable operative time and stone free rate, with significantly reduced access time and dilatation fluoroscopy time.

Establishing diagnostic reference levels for pediatric fluoroscopic examinations in a tertiary hospital

BACKGROUND

Diagnostic reference levels (DRLs) identify unusually high patient radiation exposures and are required for dose optimisation. DRLs for pediatric fluoroscopic examinations are not widely determined in Australia.

OBJECTIVE

Our objectives were to establish DRLs for pediatric fluoroscopic examinations in a South Australian tertiary hospital and compare these to previously published data and to explore relationships between patient dose area product (DAP), age and fluoroscopy times.

MATERIALS AND METHODS

Dose data from 365 pediatric patients undergoing 5 fluoroscopic examinations were retrospectively collected for a 3-year period commencing January 2018 to develop local DRLs. Relationships between DAP, age and fluoroscopy time were explored using scatterplots, Spearman's correlation, and regression analyses.

RESULTS

Local DRLs were significantly lower than data published previously, possibly reflecting technological and procedural advancements. Each 1-year increase in patient age was associated with a 0.77 μGy·m² increase in DAP for barium meal and follow-through studies (95% confidence interval [CI]=0.055, 1.48) (P=0.04), and a 1.37 μGy·m² increase in DAP for barium swallow studies (95% CI=0.61, 2.12) (P<0.001). A low correlation was demonstrated between DAP and fluoroscopy time for micturating cystourethrography studies (r=0.35, 95% CI=0.15, 0.51, P<0.001) and barium meal and follow-through studies (r=0.37, 95% CI= -0.011, 0.65, P=0.05). Age and fluoroscopy time were not significantly related.

CONCLUSION

This study provides updated Australian pediatric fluoroscopic DRLs, with the intention of promoting a national database for benchmarking pediatric doses. The local DRLs can be used for dose comparisons and optimisation between facilities.

Predicting ESWL success by determination of Hounsfield unit on non-contrast CT is clinically irrelevant in children

The necessity of determining stone density by non-contrast computerized tomography (NCCT) before extracorporeal shock wave lithotripsy (ESWL) is a controversial topic due to the radiation exposure. We aimed to investigate whether stone density is helpful in predicting the success of ESWL in pediatric patients or not. In this retrospective study, database of a single center was used to identify 232 children aged between 2 and 16 years. Patients with abnormal renal anatomy, distal obstruction, a known cystine stone disease, a previous history of an intervention regarding stone, and an insufficient follow-up period (< 3 months) were excluded from the study. A total of 209 patients were included in the study (94 with NCCT, 115 without NCCT). Groups were compared in terms of stone size, stone location, and stone-free rate at 3 months after a single ESWL session. The mean age was 6.17 ± 3.27 years and 120 (57.4%) of the patients were male and 89 (42.6%) were female. Mean stone size was 11.7 mm in NCCT group and 12.3 mm in non-NCCT group (p 0.128). The complete stone clearance rate in NCCT and non-NCCT group at 3 months after ESWL was 57.4% (54/94) and 54.7% (63/115), respectively, and there was no statistically significant difference (p 0.316). In conclusion, unnecessary NCCT use should be avoided before ESWL considering the similar success rates after ESWL and the risk of exposure to radiation.

Radiation Exposure in Pediatric Interventional Procedures

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. The expanding applications of interventional procedures coupled with the potential harmful effects of ionizing radiation highlight the need to assess the delivered radiation dose and establish an effective radiation protection program, particularly in the radiosensitive pediatric population. Given the complexity and heterogeneity of interventional procedures as well as the unique characteristics of children, the management of radiation dose is proving to be quite challenging. The aim of the current article is to provide an overview of the radiation exposure in pediatric patients during interventional procedures focusing on the importance of radiation protection in the pediatric population, the reported radiation doses and the techniques of minimizing radiation dose.

Radiation use in diagnostic imaging in children: approaching the value of the pediatric radiology community

Medical imaging is foundational in the care of children, and much of the medical imaging province depends on ionizing radiation: radiography, fluoroscopy, CT and nuclear imaging. Many considerations for this imaging in children are distinct in the domains of appropriate radiation use, other factors that determine examination quality, the opportunities to engage and educate through networking, and the translation of research efforts. Given these needs, it is worth approaching the contributions and their impact by the pediatric radiology community, especially to the enhancement of this value in the care of children.

Enough is enough: Radiation doses in children with gastrojejunal tubes

INTRODUCTION

Many children with gastric feeding intolerance require postpyloric tube feeding via a gastrojejunal (GJ) tube. Placement or positioning of these tubes is typically a procedure with a low dose of radiation. Although the risk of developing cancer from radiation exposure owing to computed tomography scans is well-documented in children, the risk of cumulative radiation exposure owing to frequent GJ tube replacement often goes unnoticed in the clinical decision-making process. We sought to define the frequency and cost of GJ tube replacement, quantify the radiation doses associated with the initial placement and replacements, and assess the number of conversions to surgical jejunostomies.

METHODS

All pediatric patients who underwent GJ tube placement or replacement by Interventional Radiology (IR), surgery, and gastroenterology between 2010 and 2018 at a single center were reviewed. We evaluated the total cost of the initial placement and replacement of each GJ tube, the total number of replacements, and the cumulative radiation dose (mGy).

RESULTS

We identified 203 patients who underwent GJ tube placement and/or replacement, of which 150 had radiation data available. Patients underwent a median of five GJ tube replacement procedures, and there was a wide range in the number of replacements per patient, from zero to 88. Patients were exposed to a median cumulative dose of 6.0 mGy (IQR: 2.2, 22.6). Nine percent of patients with available radiation data were exposed to more than 50 mGy, solely from GJ tube replacements. The median cost per replacement was $1170. The sum of the cost of the replacements for dislodged GJs translated to more than $1.4 million during the study period.

CONCLUSIONS

Overall, the average dose per GJ replacement was 3.50 mGy among all patients with available data. Nine percent of patients (14/150) were exposed to greater than 50 mGy cumulative radiation solely from GJ replacements. Patients who receive more than 50 mGy of cumulative radiation dose, who undergo seven GJ tube replacements in one year, or two consecutive GJ tube replacement procedures with radiation doses exceeding 10 mGy (per replacement) should be considered for a surgical jejunostomy.

LEVEL OF EVIDENCE

IV TYPE OF STUDY: Treatment study.

Dr. Marilyn Goske: Innovator in pediatric radiation safety and education: One in a series highlighting women recipients of the ACR Gold Medal

Committed to teaching, Dr. Goske developed an academic niche for herself focusing on educational initiatives. She co-created the widely successful Cleveland Clinic Webbased Curriculum for radiology residents, which reached acclaimed success with 65 modules used by 25,000 registrants in 53 countries and over 400 residency programs. With her natural curiosity, enthusiasm and perseverance, Dr. Goske subsequently had the vision to develop a worldwide coalition that included people from all aspects of radiology to broadcast a simple message, image gently. The influential and longstanding campaign, Image Gently, served to educate radiologists, medical physicists, radiologic technologists and most importantly, parents. Dr. Goske wanted to empower parents and the radiology community to improve pediatric patient safety and work towards decreasing radiation exposure in children. She continued her impactful work by establishing the Quality Improvement Registry in CT Scans in children in 2011 and worked as the pediatric radiology representative on the American College of Radiology's Dose Index Registry in 2013. Focused on compassionate patient care, Dr. Goske's overarching goal was to improve the patient experience throughout the many advancements in radiology. Her excellence in patient care, innovative approaches to education and safety, and collaborative ability to bring out the best in radiology led to her being the 2018 recipient of the ACR Gold Medalist, only the ninth woman ever to do so.

Fluoroscopic imaging optimization in children during percutaneous nephrolithotrispy

INTRODUCTION AND OBJECTIVES

Radiation protection management recommends radiation exposures that are as low as reasonably achievable (ALARA), while still maintaining image quality. The aim of the study is to compare radiation exposure during pediatric percutaneous nephrolithotomy (PCNL) before and after implementation of strategy for optimization of fluoroscopic imaging by measuring the Dose Area Product (DAP) and the Fluoroscopy time (FT) and study its effect on surgical outcomes.

PATIENTS & METHODS

We prospectively observed 56 children (group 1) undergoing PCNL for kidney stones in whom a radiation dose reduction strategy was adopted. The strategy included several intraoperative measures, including: optimizing position by keeping the fluoroscopy table as far from the X-ray tube as possible and the image intensifier close to the patient, preventing use of fluoroscopy for positioning, use of pulsed mode with last image hold technique, beam collimation and use of a designated fluoroscopy technician. Outcomes were compared to those in 42 children (group 2) before implementing dose reduction strategy.

RESULTS

DAP was decreased by 44% from 2.46 in group 2 to 1.38 mGy m2 in group 1 (p < 0.04). Total fluoroscopy time was significantly reduced by 55% from 100.8 s in group 2-45 s in group 1 (p < 0.002) after protocol implementation with very little loss of image quality.

CONCLUSIONS

Radiation exposure in children undergoing PCNL can be reduced significantly after optimization of fluoroscopy imaging. A reduced radiation protocol did not increase surgical complexity, operative time, or complication rates while reducing radiation exposure in a population vulnerable to its hazardous effects.

The pediatric stomach - masses and mass-like pathology

Diagnostic imaging of pediatric gastric masses often provides a challenge for the practicing radiologist. Radiologists should be aware of this relatively unusual pathology, particularly in cross-sectional imaging findings. We will review pediatric gastric masses and mass-like lesions, focusing on neoplastic and inflammatory etiologies.

Best Practices in Modified Barium Swallow Studies

Purpose The modified barium swallow study (MBSS) is a widely used videofluoroscopic evaluation of the functional anatomy and physiology of swallowing that permits visualization of bolus flow throughout the upper aerodigestive tract in real time. The information gained from the examination is critical for identifying and distinguishing the type and severity of swallowing impairment, determining the safety of oral intake, testing the effect of evidence-based frontline interventions, and formulating oral intake recommendations and treatment planning. The goal of this review article is to provide the state of the science and best practices related to MBSS. Method State of the science and best practices for MBSS are reviewed from the perspectives of speech-language pathologists (SLPs) and radiologists who clinically practice and conduct research in this area. Current quandaries and emerging clinical and research trends are also considered. Results This document provides an overview of the MBSS and standards for conducting, interpreting, and reporting the exam; the SLPs' and radiologist's perspectives on standardization of the exam; radiation exposure; technical parameters for recording and reviewing the exam; the importance of an interdisciplinary approach with engaged radiologists and SLPs; and special considerations for examinations in children. Conclusions The MBSS is the primary swallowing examination that permits visualization of bolus flow and swallowing movement throughout the upper aerodigestive tract in real time. The clinical validity of the study has been established when conducted using reproducible and validated protocols and metrics applied according to best practices to provide accurate and reliable information necessary to direct treatment planning and limit radiation exposure. Standards and quandaries discussed in this review article, as well as references, provide a basis for understanding the current best practices for MBSS.

Assessment of Patient Dose with Special Look at Pediatrics during Cardiovascular Imaging

Background

During interventional cardiology processes, patients especially women and children receive high radiation doses due to their sensitivity.

Objective

In this study, we evaluated a pediatric patient dose separately in those undergone intervention cardiac procedure.

Material and Methods

In this cross sectional study, a public hospital with 252 patients, Entrance Skin Dose (ESD) and Dose-Area Product (DAP) were recorded. Prior to the beginning of fluoroscopic procedure, the chest thickness and Body Mass Index (BMI) of patients were measured. Furthermore, kV, mAs, angle of tube and time of angiography and angioplasty were recorded.

Results

Children ratio to all patients underwent the cardiovascular imaging was 1.8. The means of patients' ESD, DAP and fluoroscopy time were 178.3±17 mGy, 1123.6±11 μGycm² and 281.4±181.2 s, respectively for coronary angiography. The females were 96.8 under 30 years and their dose mean was 276±37 mGy, 368±24 μGycm² for ESD and DAP received, respectively with 376s fluoroscopy time. Mean mAs was 359±34 and kV was 71.23±2.7. Above all, a direct and significant correlation was found between the patients' chest thickness with kV (p=0.037, r = 0.11) and mAs (p<0.001, r = 0.28) variations.

Conclusion

The results demonstrated that the number of children referred to the cardiology department and also the dose rate received by them during this test was higher than the data provided for children in developing countries. Paying attention to the children's perception of high-fluorescence time is necessary in comparison with total angiography time in order to reduce the number of radiation injuries among pediatrics.

The ABCs of Voiding Cystourethrography

Voiding cystourethrography (VCUG) demonstrates the anatomy of the urinary system and is used to detect the presence/absence of vesicoureteral reflux. It is the most important modality for urological fluoroscopic examination in children. For improved patient care, it is important to understand and perform VCUG appropriately. Therefore, an in-depth review of VCUG protocols and techniques has been presented herein. In addition, tips, tricks, and pitfalls associated with the technique have also been addressed.

Effect of using immobilization device in fluoroscopic study in pediatric patient: Focused on radiation dose reduction in voiding cystourethrogram

Introduction

To prove objective effect of using mechanical device for immobilization of pediatric patient during voiding cystourethrogram (VCUG) compare immobilization by hand-holding.

Methods

This study included 77 patients, who underwent VCUG in our center from April to October 2017, who had a clinically suspicious urinary tract infection. Patients were classified into one of two groups based on whether examination was done before (Group A) or after (Group B) adaptation of immobilization device. Patient-related data, image quality related score and dose-related data were collected and compared between two groups.

Results

Group A included 36 patients and group B included 41. Patient related data including mean age, sex, body weight and height didn’t show significant difference between two groups (p > 0.05 for all). Among the image quality scoring, overall image quality, motion artifact, showed significant difference between two groups with improved inadequate timing and centering after adaptation of immobilization device. Dose related data showed significantly decreased shot number, mean fluoroscopic time with decreased mean dose area product (DAP) value and effective dose after adaptation of immobilization device (p < 0.05 for all).

Conclusion

Adaptation of immobilization device can improve overall image quality with decreased motion artifact and improved centering and timing with even shot number, mean fluoroscopic time with decreased mean DAP value and effective dose.

A new method for reducing operation time and radiation exposure in the placement of Jamshidi needles: Technical note

Percutaneous pedicle screws have been used in the treatment of thoracolumbar fractures for decades, and conventional fluoroscopy is commonly used to confirm the positions of the Jamshidi needles during the procedure. In this article, a modified method is reported for the placement of Jamshidi needles. The attending surgeons did not receive any radiation during the procedure and the fluoroscopy time for the patients was little. In our method, all six Jamshidi needles were placed on the pedicles and hammered 2 mm into each entry site. When the verification images were acquired, the medical personnel went behind a lead-lined wall. The positions of the needles were first reviewed and adjusted as needed based on the anterior-posterior (AP) image. Then, the C-arm was rotated and lateral images were obtained to further verify the needle placement. The rest of the screw placement procedure remained the same. The proposed technique was applied in 45 patients with thoracolumbar fractures. It took an average (range) of 5 (4-7) single-shot images to ensure all the needles were positioned at the ideal entry site and 12 (10-17) minutes to complete this step. No neurological symptoms were reported by the patients. Using the proposed technique, the radiation exposure for the surgeons is zero, and the patients are well-protected from excessive radiation exposure. This modified method of embedding all the Jamshidi needles at the entry sites before fluoroscopy is an improved technique compared with the conventional method.

Reliability and validity of the neonatal feeding assessment scale (NFAS) for the early identification of dysphagia in moderate to late preterm neonates

Background

A clinical feeding assessment instrument to assist with early identification of oropharyngeal dysphagia (OPD) in neonates was developed.

Objective

To investigate the validity and reliability of the Neonatal Feeding Assessment Scale (NFAS) in comparison to the modified barium swallow study (MBSS) as gold standard.

Method

A within-subject design was implemented. A group of 48 late premature neonates (mean gestational age 35.5 weeks) were sampled in the neonatal intensive care unit.

Results

The NFAS consists of six subsections, including physiological stability, infant state, stress cues, screening of muscle tone and control, oral peripheral examination and feeding/swallowing assessment. 93% of participants (14/15) received confirmatory diagnosis of OPD on MBSS. The NFAS presented with high sensitivity (78.6%) and specificity (88.2%) scores. The positive predictive value was 78.6%. Subsequently the accuracy of the NFAS to identify the presence of OPD accurately was 85.4% when compared to MBSS. Inter-rater reliability was determined on 35% of the sample. The inter-rater agreement on overall instrument outcome was substantial beyond chance.

Conclusion

The NFAS may be of use to clinicians to support the early identification of OPD in this population, especially in resource constrained settings working without access to MBSS and to reach under served neonates.

Reducing radiation dose in paediatric interventional cardiac catheterisation

OBJECTIVE

Radiation exposure during paediatric cardiac catheterisation procedures should be minimised to "as low as reasonably achievable". The aim of this study was to evaluate the effectiveness of a modified radiation safety protocol in reducing patient dose during paediatric interventional cardiac catheterisation.

METHODS

Radiation dose data were retrospectively extracted from January 2014 to December 2015 (Standard group) and prospectively collected from January 2016 to December 2017 (Low-dose group) after implementation of a modified radiation safety protocol. Both groups included five most common procedures: atrial septal defect closure, patent ductus arteriosus closure, perimembranous ventricular septal defect closure, pulmonary valvuloplasty, and supraventricular tachycardia ablation.

RESULTS

Median air Kerma was 48.4, 50.5, 29.75, 149, 218, and 12.9 mGy for atrial septal defect closure, pulmonary valvuloplasty, patent ductus arteriosus closure <20 kg, ventricular septal defect closure <20 kg, ventricular septal defect closure ≧20 kg, and supraventricular tachycardia ablation in Standard group, respectively, which significantly decreased to 18.75, 20.7, 11.5, 41.9, 117, and 3.3 mGy in Low-dose group (p < 0.05). This represents a reduction in dose to each patient between 46 and 74%. Among five procedural types in Low-dose group, dose of ventricular septal defect closure was the highest with median air Kerma of 62.5 mGy, dose area product of 364.7 μGy.m2, and dose area product per body weight of 21.5 μGy.m2/kg, respectively, along with the longest fluoroscopy time of 9.9 minutes.

CONCLUSION

We provided a feasible radiation safety protocol with specific settings on a case-by-case basis. Increasing awareness and adequate training of a practical radiation dose reduction program are essential to improve radiation protection for children.

The Two-Point Technique for Fluoroscopic-Guided Endoscopic Procedures in Urology: A Validation Study

Introduction: The widespread use of diagnostic and therapeutic ionizing radiation raises concerns regarding excessive occupational and patient exposure. In this study, we test a novel fluoroscopic technique that has the potential to minimize radiation dose during urologic procedures. Materials and Methods: A prospective evaluation of all patients undergoing endoscopic urologic procedures in our institution was conducted. A "two-point technique (TPT)" is described in which the fluoroscope image intensifier (c-arm) is shifted between caudal and cephalad set points of the operative field. We wished to determine whether patient radiation exposure was lower with TPT than with a non-structured conventional technique, referred to as the cognitive fluoroscopic technique (CFT), in which the manipulation of the c-arm was at the discretion of the user. We obtained all clinical, radiographic, and fluoroscopic data of patients in the study period and used unpaired nonparametric statistical analysis of univariates entered stepwise into a logistic regression model. Results: A total of 106 endoscopic urologic procedures from January 2016 to November 2018 were reviewed. Forty-four (41.5%) cases were performed using TPT and 62 (58.5%) using CFT. The mean fluoroscopy time of TPT vs CFT was 71.1 (±60.8) seconds vs 104.5 (±91.6) seconds, respectively (p = 0.04), and the mean radiation dose on TPT vs CFT was 11.6 (±10.6) mGy vs 20.3 (±24.3) mGy, respectively (p = 0.03). TPT was an independent predictor of reduced operative room (OR) time and fluoro time (p < 0.05), while body mass index, age, and operator were not. Conclusion: The "TPT" helps reducing radiation dose and fluoroscopic time during endoscopic urologic procedures. The TPT is useful to lower radiation exposure to patients and OR staff.

Radiation dose monitoring in pediatric fluoroscopy: comparison of fluoroscopy time and dose-area product thresholds for identifying high-exposure cases

BACKGROUND

Fluoroscopy time has been used as a surrogate for radiation dose monitoring in pediatric fluoroscopy; however it does not account for factors such as magnification or collimation. Dose-area product (DAP) is a more accurate measure of radiation exposure but its dependence on patient weight and body-part thickness is a challenge in children of varying ages.

OBJECTIVE

To determine whether fluoroscopy time and DAP produce concurrent results when they are used to identify high-exposure cases, and to establish radiation dose thresholds for our institution.

MATERIALS AND METHODS

During a 2-year period we prospectively monitored pediatric fluoroscopy studies performed at the Children's Hospital at Montefiore. We recorded study type, fluoroscopy time, DAP, patient age, weight and height. We then calculated 90th percentile fluoroscopy time and DAP thresholds for weight and age.

RESULTS

We evaluated 1,011 cases (453 upper gastrointestinal [UGI] series, 266 voiding cystourethrograms [VCUGs], 120 contrast enemas, 108 speech studies, and 64 esophagrams). Fluoroscopy time demonstrated moderate correlation with DAP (r_s=0.45, P<0.001, Spearman rank). DAP strongly correlated with patient weight (r_s=0.71, P<0.001) and age (r_s=0.70, P<0.001). Concordance of cases exceeding 90th percentile thresholds for fluoroscopy time and DAP were κ=0.27 for UGI series and κ=0.49 for VCUG for weight-based cutoffs, and κ=0.36 for UGI series and κ=0.40 for VCUG for age-based cutoffs.

CONCLUSION

The limited correlation of fluoroscopy time with DAP suggests these methods are not equivalent for dose monitoring. However, the strong correlation of DAP with patient weight and age presents a challenge for establishing DAP thresholds in children, who range widely in size. Despite controlling for weight or age, there was limited overlap of cases exceeding the 90th percentile threshold for fluoroscopy time and DAP. This further reinforces the non-overlapping outcome of these two methods and indicates that fluoroscopy time might be inadequate for dose monitoring.

Effect of Reader and Patient Parameters on the Performance of Last-Image-Hold for Fluoroscopic Grading of Vesicoureteric Reflux

OBJECTIVE. The purpose of this study is to determine the effect of different reader and patient parameters on the degree of agreement and the rate of misclassification of vesicoureteric reflux grading on last-image-hold frames in relation to spot-exposed frames from voiding cystourethrography (VCUG) as well as to determine the nature of reflux misclassification on last-image-hold frames. MATERIALS AND METHODS. Blinded readers conducted a retrospective evaluation of last-image-hold and spot-exposed frames of the renal fossae from 191 sequential VCUG examinations performed during a five-year period. Kappa tests were used to determine the agreement between reflux gradings and to assess the impact of reader and patient parameters. Pearson product-moment correlations were used to evaluate the effect of patient parameters on reader level of certainty regarding reflux grading. RESULTS. We measured almost perfect overall agreement for more experienced readers and substantial overall agreement for less experienced readers. Point estimates of overall misclassification were less than 2% for more experienced readers and less than 4% for less experienced readers. The readers' level of certainty about reflux grading had a positive impact on agreement values and misclassification rates. Experienced readers' most common misclassification was assigning reflux a grade of 3 on a spot-exposed frame and a grade of 2 on an equivalent last-image-hold frame. Inexperienced readers' most common misclassification involved missing reflux altogether. CONCLUSION. Instances of grade 2 reflux on last-image-hold frames may warrant supplemental evaluation with spot-exposed frames. Otherwise, a reader's level of certainty regarding reflux grading on a last-image-hold frame may help determine whether a supplemental spot-exposed frame would be beneficial.

Pediatric voiding cystourethrography: An essential examination for urologists but a terrible experience for children

Voiding cystourethrography is the most important fluoroscopic examination in pediatric urology for the investigation of lower urogenital tract diseases, such as vesicoureteral reflux or urethral stricture. However, this invasive procedure imposes a significant burden on children and their parents, and recently there has been a paradigm shift in the diagnosis and treatment of vesicoureteral reflux. In the 2011 revision, the American Academy of Pediatrics guidelines on urinary tract infection recommended abandoning routine voiding cystourethrography after the first febrile urinary tract infection. In 2014, the randomized intervention for children with vesicoureteral reflux study recommended discontinuation of routine continuous antibiotic prophylaxis for vesicoureteral reflux. The time is now ripe to radically reconsider indications for voiding cystourethrography and the procedure itself.

The effect of surgeon versus technologist control of fluoroscopy on radiation exposure during pediatric ureteroscopy: A randomized trial

BACKGROUND

Fluoroscopy is commonly used during pediatric ureteroscopy (PURS) for urolithiasis, and the most important contributor to overall radiation exposure is fluoroscopy time (FT). One factor that may impact FT is who controls activation of the fluoroscope: the urologist (with a foot pedal) or the radiation technologist (as directed by the urologist). While there are plausible reasons to believe that either approach may lead to reduced FT, there are no systematic investigations of this question. We sought to compare FT with surgeon-control versus technologist control during PURS for urolithiasis.

METHODS

We conducted a randomized controlled trial (Clinicaltrials.gov ID number: NCT02224287). Institutional Review Board approval was sought and obtained for this study. All subjects (or their legal guardians) provided informed consent. Each patient (age 5-26 years) was randomized to surgeon- or technologist-controlled fluoroscope activation. Block randomization was stratified by the surgeon. For technologist control, the surgeon verbally directed the technologist to activate the fluoroscope. For surgeon control, a foot pedal was used by the surgeon. The technologist controlled c-arm positioning, settings, and movement. The primary outcome was total FT for the procedure. Secondary outcomes included radiation exposure (entrance surface air kerma [ESAK] mGy). We also analyzed clinical and procedural predictors of FT and exposure. Mixed linear models accounting for clustering by surgeon were developed.

RESULTS

Seventy-three procedures (5 surgeons) were included. The number of procedures per surgeon ranged from seven to 36. Forty-three percent were pre-stented. Thirty-one procedures were left side, 35 were right side, and seven were bilateral. Stones were treated in 71% of procedures (21% laser, 14% basket, and 65% laser/basket). Stone locations were distal ureter (11.5%), proximal/mid-ureter (8%), renal (69%), and ureteral/renal (11.5%). An access sheath was used in 77%. Median stone size was 8.0 mm (range 2.0-20.0). Median FT in the surgeon control group was 0.5 min (range 0.01-6.10) versus 0.55 min (range 0.10-5.50) in the technologist-control group (p = 0.284). Median ESAK in the surgeon control group was 46.02 mGy (range 5.44-3236.80) versus 46.99 mGy (range: 0.17-1039.31) in the technologist-control group (p = 0.362). Other factors associated with lower FT on univariate analysis included female sex (p = 0.015), no prior urologic surgeries (p = 0.041), shorter surgery (p = 0.011), and no access sheath (p = 0.006). On multivariable analysis only female sex (p = 0.017) and no access sheath (p = 0.049) remained significant. There was significant variation among surgeons (p < 0.0001); individual surgeon median FT ranged from 0.40 to 2.95 min.

CONCLUSIONS

Fluoroscopy time and radiation exposure are similar whether the surgeon or technologist controls fluoroscope activation. Other strategies to reduce exposure might focus on surgeon-specific factors, given the significant variation between surgeons.

Educational Effects of Radiation Reduction During Fluoroscopic Examination of the Adult Gastrointestinal Tract

RATIONALE AND OBJECTIVES

This study aimed to evaluate the effects of educating radiology residents and radiographers about radiation exposure on reduction of dose area product (DAP) and fluoroscopy time in diagnostic fluoroscopy of the gastrointestinal (GI) tract in adult patients.

MATERIALS AND METHODS

In April 2015, we offered 1 hour of education to radiology residents and radiographers on how to reduce radiation doses during fluoroscopic examinations. Fluoroscopic examinations of the GI tracts of adult patients performed from June 2014 to February 2016 were evaluated. A total of 2326 fluoroscopic examinations (779 and 1547 examinations before and after education, respectively) were performed, including 10 kinds of examinations. Fluoroscopy time and DAP were collected. A radiologist evaluated the number of spot images, captured images, cine video, captured video, and the use of collimation or magnification. We used the Mann-Whitney U test to assess the difference in fluoroscopy-related factors before and after education.

RESULTS

Median DAP decreased significantly after education, from 21.1 to 18.2 Gy∙cm² (P < .001) in all examinations. After education DAP decreased significantly in defecography (P < .001) and fluoroscopy time decreased significantly in upper gastrointestinal series with water-soluble contrast (P < .001). Spot and cine images that increased the radiation dose were used less frequently after education than before in some kinds of examinations, especially in defecography (P < .001). More images were collimated after education in barium swallow than before (P < .001).

CONCLUSIONS

Educating radiologist residents and radiographers could reduce DAP in fluoroscopy examinations of the GI tract in adult patients.

Pulsation and Collimation During Fluoroscopy to Decrease Radiation: A Cadaver Study

Background

Awareness of the harmful effects of long-term low-dose radiation is rising. Many studies have assessed both patient and physician exposure to radiation in association with the use of fluoroscopy in the operating room. However, to our knowledge, previous studies have not assessed, in a detailed fashion, the reduction in radiation exposure that pulsation and collimation provide.

Methods

Seven fresh cadavers were irradiated for 5 minutes with C-arm fluoroscopy with use of standard x-ray and pulsed and collimated x-ray beams. The x-ray sources were placed under the table, over the table, and lateral to the table. Radiation exposure doses were measured at different points, such as the center of the radiation field on the cadaver as well as at the locations of the surgeon's hand and thyroid gland. In addition, Monte Carlo simulation (a physics equation to predict exposure) was performed to estimate the dose reduction and to confirm the experimental results.

Results

The radiation exposure doses associated with the use of pulsed fluoroscopy (8 times per second) were reduced by approximately 30% for the patient and by approximately 70% for the surgeon's hand and thyroid gland as compared with those associated with the use of continuous fluoroscopy. The radiation exposure doses associated with the use of collimated beams were reduced to approximately 65% for the surgeon's hand and thyroid gland as compared with those associated with the use of non-collimated fluoroscopy. These results were consistent with the simulation, and the phenomena could be appropriately explained by physics.

Conclusions

The present study revealed the effectiveness of pulsed and collimated x-ray beams in reducing radiation exposure doses resulting from C-arm fluoroscopy. Surgeons should consider using the techniques of pulsed fluoroscopy and collimation to protect patients and themselves from radiation.

Clinical Relevance

This study presents data regarding the reduction of radiation exposure provided by pulsed fluoroscopy and collimation.

Radiation exposure during intramedullary nailing

Surgeons should aim to keep radiation exposure "As Low As Reasonably Achievable (ALARA)" during intramedullary nailing and other minimally invasive surgical procedures. This requires understanding the principles of ionizing radiation and methods for minimizing exposure risk. The main source of radiation exposure to surgical personnel during fluoroscopy is from scattered radiation. Since radiation scatter is mainly directed towards the fluoroscopy source, the best configuration during surgery to reduce radiation dose to the surgeon is to position the fluoroscopic source below the operating room table and the image collector above the table. During cross table imaging, the surgeon should stand on the side with the image collector to minimize their exposure to radiation scatter. To reduce scattered radiation the patient must be placed as close to the image collector and as far away from the x-ray tube as possible. Standing farther away from the patient can exponentially reduce radiation exposure. The hands usually have the greatest dose exposure to radiation during surgical procedures, but they are far less radiosensitive than the eyes or thyroid. To minimize exposure to the hands, a surgeon should use the hands-off technique taking fluoroscopic images only when his or her hands are farthest from the radiographic field. Lead gowns, lead thyroid shields, and lead glasses, further reduces an individual's exposure to radiation.

Pre-procedural scout radiographs are unnecessary for routine pediatric fluoroscopic examinations

BACKGROUND

Although practice patterns vary, scout radiographs are often routinely performed with pediatric fluoroscopic studies. However few studies have evaluated their utility in routine pediatric fluoroscopy.

OBJECTIVE

To evaluate the value of scout abdomen radiographs in routine barium or water-soluble enema, upper gastrointestinal (GI) series, and voiding cystourethrogram pediatric fluoroscopic procedures.

MATERIALS AND METHODS

We retrospectively evaluated 723 barium or water-soluble enema, upper GI series, and voiding cystourethrogram fluoroscopic procedures performed at our institution. We assessed patient history and demographics, clinical indication for the examination, prior imaging findings and impressions, scout radiograph findings, additional findings provided by the scout radiograph that were previously unknown, and whether the scout radiograph contributed any findings that significantly changed management.

RESULTS

We retrospectively evaluated 723 fluoroscopic studies (368 males and 355 females) in pediatric patients. Of these, 700 (96.8%) had a preliminary scout radiograph. Twenty-three (3.2%) had a same-day radiograph substituted as a scout radiograph. Preliminary scout abdomen radiographs/same-day radiographs showed no new significant findings in 719 (99.4%) studies. New but clinically insignificant findings were seen in 4 (0.6%) studies and included umbilical hernia, inguinal hernia and hip dysplasia. No findings were found on the scout radiographs that would either alter the examination performed or change management with regard to the exam.

CONCLUSION

Pre-procedural scout abdomen radiographs are unnecessary in routine barium and water-soluble enema, upper GI series, and voiding cystourethrogram pediatric fluoroscopic procedures and can be substituted with a spot fluoroscopic last-image hold.

Internally Randomized Control Trial of Radiation Exposure Using Ultra-low Radiation Imaging Versus Traditional C-arm Fluoroscopy for Patients Undergoing Single-level Minimally Invasive Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

To compare radiation exposure between ultra-low radiation imaging (ULRI) with image enhancement and standard-dose fluoroscopy for patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

SUMMARY OF BACKGROUND DATA

Although the benefits of MIS are lauded by many, there is a significant amount of radiation exposure to surgeon and operating room personnel. Our goal with this work was to see if by using ultra-low dose radiation settings coupled with image enhancement, this exposure could be minimized.

METHODS

An institutional review board approved, prospective, internally randomized controlled trial was performed comparing ultra-low dose settings coupled with image enhancement software to conventional fluoroscopic imaging. In this study, each patient served as their own control, randomly assigning one side of MIS-TLIF for cannulation and K-wire placement using each imaging modality. Further, the case was also randomly divided into screw placement and cage placement/final images to allow further comparisons amongst patients. Radiation production from the C-arm fluoroscope and radiation exposure to all operating room personnel were recorded.

RESULTS

Twenty-four patients were randomly assigned to undergo a single level MIS-TLIF. In no case was low radiation imaging abandoned, and no patient had a neurologic decline or required hardware repositioning. Everyone in the operating room-the physician, scrub nurse, circulator, and anesthesiologist-all benefited with 61.6% to 83.5% reduction in radiation exposure during cannulation and K-wire placement to screw insertion aided by ULRI. In every case but the anesthesiologist dose, this was statistically significant (P < 0.05). This benefit required no additional time (P = 0.78 for K-wire placement).

CONCLUSION

ULRI, when aided by image enhancement software, affords the ability for all parties in the operating room to substantially decrease their radiation exposure compared with standard-dose C-arm fluoroscopy without adding additional time or an increased complication rate.

LEVEL OF EVIDENCE

2.

Preliminary psychometric performance of the Neonatal Feeding Assessment Scale

Objective

The objective was to determine the preliminary psychometric performance of a new clinical feeding scale to diagnose oropharyngeal dysphagia (OPD) in neonates.

Methods

Twenty neonates with a median gestational age of 35 weeks were evaluated using the Neonatal Feeding Assessment Scale (NFAS) and modified barium swallow studies (MBSS). The results were compared.

Results

Nine of the 20 participants presented with OPD on the NFAS. Comparison of the scale’s results with instrumental MBSS indicated that all participants without OPD were correctly excluded (100% sensitivity). The specificity was 78.6%, indicating that three participants were falsely identified with OPD on the scale. Inter-rater reliability was determined on 50% (n = 10) of the sample. Substantial agreement (80%) was obtained between two raters in five of the six sections of the scale and on the diagnostic outcome.

Conclusion

The preliminary performance of the scale appears to be promising. A further validation study will take place.

Radiation exposure contribution of the scout abdomen radiograph in common pediatric fluoroscopic procedures

BACKGROUND

Contrast enema, voiding cystourethrography and upper gastrointestinal studies are the most common fluoroscopic procedures in children. Scout abdomen radiographs have been routinely obtained prior to fluoroscopy and add to the radiation exposure from these procedures. Elimination of unnecessary routine scout radiographs in select studies might significantly reduce radiation exposure to children and improve the overall benefit-to-risk ratio of these fluoroscopic procedures.

OBJECTIVE

To determine the radiation exposure contribution of the preliminary/scout abdomen radiographs with respect to the radiation exposure of the total procedure.

MATERIALS AND METHODS

We retrospectively collected demographic information and radiation exposure values of dose area product (in Gy-cm(2)) and entrance air kerma (in mGy) - initially for the scout abdomen radiographs done prior to fluoroscopy and subsequently the total procedural radiation values (the combined values of the scout radiograph and fluoroscopic radiation exposure) - in children who underwent contrast enemas, voiding cystourethrograms and upper gastrointestinal studies in a 4-month period. The radiation parameters, including fluoroscopy time, dose area product and entrance air kerma, were available in the log book maintained in the fluoroscopy suite. Fluoroscopy procedures were performed on a single fluoroscopy machine using four frames per second pulse rate and other radiation-minimizing techniques. Usage of the grid to obtain scout radiographs was also recorded. The proportion of radiation exposure from the scout radiograph relative to that of the total procedure was calculated by dividing the individual parameters of the scout to the total procedural values and multiplied by 100 to express these values as a percentage. We calculated mean, median and range and performed statistical analysis of the data.

RESULTS

A total of 151 procedures performed on 71 males and 80 females qualified for the study. The age range of the patients was 2 days to 18 years, with a mean of nearly 3.5 years (40 months) and median of 15 months. There were 63 upper gastrointestinal studies, 65 voiding cystourethrography studies and 23 contrast enema studies. The fluoroscopy time for all procedures combined ranged from 0.1 min (6 s) to 2 min, with mean and median values of 0.4 min and 0.3 min, respectively. The fractional radiation exposure contribution for the dose area product of scout abdomen radiograph to the total procedure ranged from 4% to 98%, with mean and median values of 51% and 49%, respectively. The fractional contribution of the scout radiograph to the total procedure for the entrance air kerma values ranged from 6% to 97%, with mean and median values of 29% and 26%, respectively. There was a significant negative correlation (P<0.001) between fluoroscopy radiation time and the proportion of radiation parameters of scout radiograph to total procedural values.

CONCLUSION

Scout radiographs can contribute a significant proportion (median values of approximately 50% for the dose area product and 26% for the entrance air kerma) of radiation exposure in common fluoroscopy procedures in children.

Impact of imaging approach on radiation dose and associated cancer risk in children undergoing cardiac catheterization

OBJECTIVES

To quantify the impact of image optimization on absorbed radiation dose and associated risk in children undergoing cardiac catheterization.

BACKGROUND

Various imaging and fluoroscopy system technical parameters including camera magnification, source-to-image distance, collimation, antiscatter grids, beam quality, and pulse rates, all affect radiation dose but have not been well studied in younger children.

METHODS

We used anthropomorphic phantoms (ages: newborn and 5 years old) to measure surface radiation exposure from various imaging approaches and estimated absorbed organ doses and effective doses (ED) using Monte Carlo simulations. Models developed in the National Academies' Biological Effects of Ionizing Radiation VII report were used to compare an imaging protocol optimized for dose reduction versus suboptimal imaging (+20 cm source-to-image-distance, +1 magnification setting, no collimation) on lifetime attributable risk (LAR) of cancer.

RESULTS

For the newborn and 5-year-old phantoms, respectively ED changes were as follows: +157% and +232% for an increase from 6-inch to 10-inch camera magnification; +61% and +59% for a 20 cm increase in source-to-image-distance; -42% and -48% with addition of 1-inch periphery collimation; -31% and -46% with removal of the antiscatter grid. Compared with an optimized protocol, suboptimal imaging increased ED by 2.75-fold (newborn) and fourfold (5 years old). Estimated cancer LAR from 30-min of posteroanterior fluoroscopy using optimized versus suboptimal imaging, respectively was 0.42% versus 1.23% (newborn female), 0.20% versus 0.53% (newborn male), 0.47% versus 1.70% (5-year-old female) and 0.16% versus 0.69% (5-year-old male).

CONCLUSIONS

Radiation-related risks to children undergoing cardiac catheterization can be substantial but are markedly reduced with an optimized imaging approach. © 2016 Wiley Periodicals, Inc.

Patient and surgeon radiation exposure during spinal instrumentation using intraoperative computed tomography-based navigation

BACKGROUND CONTEXT

Imaging modalities used to visualize spinal anatomy intraoperatively include X-ray studies, fluoroscopy, and computed tomography (CT). All of these emit ionizing radiation.

PURPOSE

Radiation emitted to the patient and the surgical team when performing surgeries using intraoperative CT-based spine navigation was compared.

STUDY DESIGN/SETTING

This is a retrospective cohort case-control study.

PATIENT SAMPLE

Seventy-three patients underwent CT-navigated spinal instrumentation and 73 matched controls underwent spinal instrumentation with conventional fluoroscopy.

OUTCOME MEASURES

Effective doses of radiation to the patient when the surgical team was inside and outside of the room were analyzed. The number of postoperative imaging investigations between navigated and non-navigated cases was compared.

METHODS

Intraoperative X-ray imaging, fluoroscopy, and CT dosages were recorded and standardized to effective doses. The number of postoperative imaging investigations was compared with the matched cohort of surgical cases. A literature review identified historical radiation exposure values for fluoroscopic-guided spinal instrumentation.

RESULTS

The 73 navigated operations involved an average of 5.44 levels of instrumentation. Thoracic and lumbar instrumentations had higher radiation emission from all modalities (CT, X-ray imaging, and fluoroscopy) compared with cervical cases (6.93 millisievert [mSv] vs. 2.34 mSv). Major deformity and degenerative cases involved more radiation emission than trauma or oncology cases (7.05 mSv vs. 4.20 mSv). On average, the total radiation dose to the patient was 8.7 times more than the radiation emitted when the surgical team was inside the operating room. Total radiation exposure to the patient was 2.77 times the values reported in the literature for thoracolumbar instrumentations performed without navigation. In comparison, the radiation emitted to the patient when the surgical team was inside the operating room was 2.50 lower than non-navigated thoracolumbar instrumentations. The average total radiation exposure to the patient was 5.69 mSv, a value less than a single routine lumbar CT scan (7.5 mSv). The average radiation exposure to the patient in the present study was approximately one quarter the recommended annual occupational radiation exposure. Navigation did not reduce the number of postoperative X-rays or CT scans obtained.

CONCLUSIONS

Intraoperative CT navigation increases the radiation exposure to the patient and reduces the radiation exposure to the surgeon when compared with values reported in the literature. Intraoperative CT navigation improves the accuracy of spine instrumentation with acceptable patient radiation exposure and reduced surgical team exposure. Surgeons should be aware of the implications of radiation exposure to both the patient and the surgical team when using intraoperative CT navigation.

Paediatric doses during some common X-ray procedures at selected referral hospitals in Tanzania

The aim of this study was to determine the radiation doses to paediatric patients of different age groups at three large hospitals for optimisation purposes. The entrance surface air kerma (ESAK) values were determined from the measured X-ray output values using calibrated ionisation chamber, TW 233612 and clinical patient parameters. The air kerma-area product (KAP) values were measured using a calibrated Diamentor E2 system. The volume computed tomography dose index (CTDIvol) and dose length product (DLP) values were obtained from the computed tomography (CT) equipment verified by a calibrated CT chamber, Unifors Xi CT. Irrespective of age groups, the results show that the median ESAK values ranged from 62.6 to 248.1 µGy. The median KAP values ranged from 135.6 to 1612 µGy cm(2), while the median DLP values ranged from 119.1 to 600 mGy cm. Analysis of the results indicates that optimisation can be achieved through good practice awareness and patient dose and image quality evaluations.

Reducing Radiation Dose in Pediatric Diagnostic Fluoroscopy

PURPOSE

To assess radiation dose in common pediatric diagnostic fluoroscopy procedures and determine the efficacy of dose tracking and dose reduction training to reduce radiation use.

METHODS

Fluoroscopy time and radiation dose area product (DAP) were recorded for upper GIs (UGI), voiding cystourethrograms (VCUGs), and barium enemas (BEs) during a six-month period. The results were presented to radiologists followed by a 1-hour training session on radiation dose reduction methods. Data were recorded for an additional six months. DAP was normalized to fluoroscopy time, and Wilcoxon testing was used to assess for differences between groups.

RESULTS

Data from 1,479 cases (945 pretraining and 530 post-training) from 9 radiologists were collected. No statistically significant difference was found in patient age, proportion of examination types, or fluoroscopy time between the pre- and post-training groups (P ≥ .1), with the exception of a small decrease in median fluoroscopy time for VCUGs (1.0 vs 0.9 minutes, P = .04). For all examination types, a statistically significant decrease was found in the median normalized DAP (P < .05) between pre- and post-training groups. The median (quartiles) for pretraining and post-training normalized DAPs (μGy·m(2) per minute) were 14.36 (5.00, 38.95) and 6.67 (2.67, 17.09) for UGIs; 13.00 (5.34, 32.71) and 7.16 (2.73, 19.85) for VCUGs; and 33.14 (9.80, 85.26) and 17.55 (7.96, 46.31) for BEs.

CONCLUSIONS

Radiation dose tracking with feedback, paired with dose reduction training, can reduce radiation dose during diagnostic pediatric fluoroscopic procedures by nearly 50%.

Comparison of pediatric radiation dose and vessel visibility on angiographic systems using piglets as a surrogate: antiscatter grid removal vs. lower detector air kerma settings with a grid - a preclinical investigation

The purpose of this study was to reduce pediatric doses while maintaining or improving image quality scores without removing the grid from X‐ray beam. This study was approved by the Institutional Animal Care and Use Committee. Three piglets (5, 14, and 20 kg) were imaged using six different selectable detector air kerma (Kair) per frame values (100%, 70%, 50%, 35%, 25%, 17.5%) with and without the grid. Number of distal branches visualized with diagnostic confidence relative to the injected vessel defined image quality score. Five pediatric interventional radiologists evaluated all images. Image quality score and piglet Kair were statistically compared using analysis of variance and receiver operating curve analysis to define the preferred dose setting and use of grid for a visibility of 2nd and 3rd order vessel branches. Grid removal reduced both dose to subject and imaging quality by 26%. Third order branches could only be visualized with the grid present; 100% detector Kair was required for smallest pig, while 70% detector Kair was adequate for the two larger pigs. Second order branches could be visualized with grid at 17.5% detector Kair for all three pig sizes. Without the grid, 50%, 35%, and 35% detector Kair were required for smallest to largest pig, respectively. Grid removal reduces both dose and image quality score. Image quality scores can be maintained with less dose to subject with the grid in the beam as opposed to removed. Smaller anatomy requires more dose to the detector to achieve the same image quality score.

PACS numbers: 87.53.Bn, 87.57.N‐, 87.57.cj, 87.59.cf, 87.59.Dj

Safety and efficacy of expanded polytetrafluoroethylene-covered transjugular intrahepatic portosystemic shunts in children with acute or recurring upper gastrointestinal bleeding

BACKGROUND

The transjugular intrahepatic portosystemic shunt (TIPS) is effective for treating complications of portal hypertension in cirrhotic adults but the experience in children is limited.

OBJECTIVE

To retrospectively review the safety and efficacy of expanded polytetrafluoroethylene (ePTFE)-covered TIPS in children with acute or recurrent gastrointestinal bleeding.

MATERIALS AND METHODS

We reviewed the medical records of children who received implants of 10-mm-diameter PTFE-covered endoprostheses for acute or recurring upper gastrointestinal bleeding caused by medically or endoscopically uncontrollable varices. The recurrence of upper gastrointestinal bleeding, associated complications and permeability were assessed with Doppler sonography sequentially or up to transplantation.

RESULTS

In all children (n = 12; mean age 9 years; mean weight 30 kg) a single endoprosthesis was implanted with no associated mortality. The mean initial transhepatic gradient was 15 mmHg (range 3-21 mmHg), dropping to 7 mmHg (range 1-12 mmHg) after TIPS. Immediate complications were mild encephalopathy (n = 1) and acute occlusion of the TIPS (n = 1). Stenosis of the TIPS was observed in two children, at 9 months and 54 months follow-up, and thrombosis was observed in two children, at 7 months and 12 months follow-up. All four stenoses/occlusions were resolved with coaxial endoprostheses.

CONCLUSION

The safety profile and efficacy of expanded polytetrafluoroethylene (ePTFE)-covered TIPS were satisfactory in this small series of children with acute or recurrent gastrointestinal bleeding.