Kimberly E. Applegate

Image Gently: Ten Steps You Can Take to Optimize Image Quality and Lower CT Dose for Pediatric Patients

AJR:194, April 2010 This article suggests 10 steps that radiologists and radiologic technologists, with the assistance of their medical physicist, can take to obtain good quality CT images while properly managing radiation dose for children undergoing CT. The first six steps ideally should be completed before performing any CT on a pediatric patient. The final four steps address the unique consideration that should be given for each scanned patient.

The 'Image Gently' campaign: increasing CT radiation dose awareness through a national education and awareness program

ALARA (As Low As Reasonably Achievable) has been a guiding principle for pediatric radiologists for decades. The Society for Pediatric Radiology (SPR) has long been a leader in promoting safety in radiology practice in children. However, the ALARA principle has taken on new meaning in the past several years as the number of CT scans in children has skyrocketed. For example, it is estimated that since the 1980s when CT was beginning its ascendancy there has been up to an 800% increase. CT scans in children provide great benefit in patient care when used appropriately. However, increased use requires a team approach to ensure that only indicated exams are performed and at the Pediatr Radiol (2008) 38:265–269 DOI 10.1007/s00247-007-0743-3

Clinical Practice Guideline for the Diagnosis and Management of Acute Bacterial Sinusitis in Children Aged 1 to 18 Years

OBJECTIVE: To update the American Academy of Pediatrics clinical practice guideline regarding the diagnosis and management of acute bacterial sinusitis in children and adolescents. METHODS: Analysis of the medical literature published since the last version of the guideline (2001). RESULTS: The diagnosis of acute bacterial sinusitis is made when a child with an acute upper respiratory tract infection (URI) presents with (1) persistent illness (nasal discharge [of any quality] or daytime cough or both lasting more than 10 days without improvement), (2) a worsening course (worsening or new onset of nasal discharge, daytime cough, or fever after initial improvement), or (3) severe onset (concurrent fever [temperature ≥39°C/102.2°F] and purulent nasal discharge for at least 3 consecutive days). Clinicians should not obtain imaging studies of any kind to distinguish acute bacterial sinusitis from viral URI, because they do not contribute to the diagnosis; however, a contrast-enhanced computed tomography scan of the paranasal sinuses should be obtained whenever a child is suspected of having orbital or central nervous system complications. The clinician should prescribe antibiotic therapy for acute bacterial sinusitis in children with severe onset or worsening course. The clinician should either prescribe antibiotic therapy or offer additional observation for 3 days to children with persistent illness. Amoxicillin with or without clavulanate is the first-line treatment of acute bacterial sinusitis. Clinicians should reassess initial management if there is either a caregiver report of worsening (progression of initial signs/symptoms or appearance of new signs/symptoms) or failure to improve within 72 hours of initial management. If the diagnosis of acute bacterial sinusitis is confirmed in a child with worsening symptoms or failure to improve, then clinicians may change the antibiotic therapy for the child initially managed with antibiotic or initiate antibiotic treatment of the child initially managed with observation. CONCLUSIONS: Changes in this revision include the addition of a clinical presentation designated as “worsening course,” an option to treat immediately or observe children with persistent symptoms for 3 days before treating, and a review of evidence indicating that imaging is not necessary in children with uncomplicated acute bacterial sinusitis.

Second Malignant Neoplasms and Cardiovascular Disease Following Radiotherapy

Second malignant neoplasms (SMNs) and cardiovascular disease (CVD) are among the most serious and life-threatening late adverse effects experienced by the growing number of cancer survivors worldwide and are due in part to radiotherapy. The National Council on Radiation Protection and Measurements (NCRP) convened an expert scientific committee to critically and comprehensively review associations between radiotherapy and SMNs and CVD, taking into account radiobiology; genomics; treatment (ie, radiotherapy with or without chemotherapy and other therapies); type of radiation; and quantitative considerations (ie, dose-response relationships). Major conclusions of the NCRP include: 1) the relevance of older technologies for current risk assessment when organ-specific absorbed dose and the appropriate relative biological effectiveness are taken into account and 2) the identification of critical research needs with regard to newer radiation modalities, dose-response relationships, and genetic susceptibility. Recommendation for research priorities and infrastructural requirements include 1) long-term large-scale follow-up of extant cancer survivors and prospectively treated patients to characterize risks of SMNs and CVD in terms of radiation dose and type; 2) biological sample collection to integrate epidemiological studies with molecular and genetic evaluations; 3) investigation of interactions between radiotherapy and other potential confounding factors, such as age, sex, race, tobacco and alcohol use, dietary intake, energy balance, and other cofactors, as well as genetic susceptibility; 4) focusing on adolescent and young adult cancer survivors, given the sparse research in this population; and 5) construction of comprehensive risk prediction models for SMNs and CVD to permit the development of follow-up guidelines and prevention and intervention strategies.

Use of Medical Imaging Procedures With Ionizing Radiation in Children: A Population-Based Study

OBJECTIVE To determine population-based rates of the use of diagnostic imaging procedures with ionizing radiation in children, stratified by age and sex. DESIGN Retrospective cohort analysis. SETTING All settings using imaging procedures with ionizing radiation. PATIENTS Individuals younger than 18 years, alive, and continuously enrolled in UnitedHealthcare between January 1, 2005, and December 31, 2007, in 5 large US health care markets. MAIN OUTCOME MEASURES Number and type of diagnostic imaging procedures using ionizing radiation in children. RESULTS A total of 355 088 children were identified; 436 711 imaging procedures using ionizing radiation were performed in 150 930 patients (42.5%). The highest rates of use were in children older than 10 years, with frequent use in infants younger than 2 years as well. Plain radiography accounted for 84.7% of imaging procedures performed. Computed tomographic scans-associated with substantially higher doses of radiation-were commonly used, accounting for 11.9% of all procedures during the study period. Overall, 7.9% of children received at least 1 computed tomographic scan and 3.5% received 2 or more, with computed tomographic scans of the head being the most frequent. CONCLUSIONS Exposure to ionizing radiation from medical diagnostic imaging procedures may occur frequently among children. Efforts to optimize and ensure appropriate use of these procedures in the pediatric population should be encouraged.

Cohort Study of Structured Reporting Compared with Conventional Dictation

PURPOSE To determine if radiology residents who used a structured reporting system (SRS) produced higher quality reports than residents who used conventional free-text dictation to report cranial magnetic resonance (MR) imaging in patients suspected of having a stroke. MATERIALS AND METHODS The study was approved by an institutional review board and was HIPAA compliant; informed consent was obtained. This study included residents, with 16 in the control group and 18 in the intervention group. For phase 1, each subject reviewed the same set of 25 brain MR imaging cases and dictated the cases by using free-text conventional dictation. For phase 2, 4 months later, the control group repeated the same process, whereas the intervention group reread the same MR imaging cases by using SRS to create reports. Resident-generated reports were graded for accuracy and completeness by a neuroradiologist on the basis of consensus interpretations and criterion standard diagnoses as established with at least 6 months of clinical follow-up, imaging follow-up, and/or histologic examination where appropriate. Accuracy and completeness scores were analyzed by using a Wilcoxon signed rank test for paired data and a Mann-Whitney U test for nonpaired data. Intervention group residents were surveyed regarding their opinions of SRS. RESULTS For phase 1 reports, no significant difference in accuracy or completeness scores between control and intervention groups was found. Decreases in accuracy (91.5 to 88.7) and completeness (68.7 to 54.3) scores for phase 2 compared with phase 1 for the intervention group were found; increases in accuracy (91.4 to 92.4) and completeness (67.8 to 71.7) scores for phase 2 compared with phase 1 for the control group were found (all P values < .001). The most common complaints were that the SRS was overly constraining with regard to report content and was time-consuming to use. CONCLUSION While there are many potential benefits of structuring radiology reports, such changes cannot be assumed to improve report accuracy or completeness. Any SRS should be tested for effect on intrinsic report quality.

Intussusception in children: evidence-based diagnosis and treatment

Keywords Intussusception.Infantsandchildren.Enema.BowelobstructionIntroduction and goals of imagingIntussusception is an invagination of the bowel into itself,usually involving both small and large bowel. The moreproximal bowel that herniates into more distal bowel iscalled the intussusceptum and bowel that contains it is calledthe intussuscipiens. It is an emergent condition where delayin diagnosis is common, which may lead to bowelperforation, obstruction, and necrosis. Most cases in infantsand young children are ‘idiopathic’ in that the etiology of theintussusception is due to hypertrophied lymphoid tissue inthe terminal ileum which results in ileocolic intussusception.The goal of initial bowel imaging is early detection (orexclusion)ofintussusceptiontoenableenemareductionoftheintussusception.Additionalimagingstudiesmaybeperformedto further characterize indeterminate results, possible leadpoints,incompletereduction,andrecurrenceofintussusception.EpidemiologyIntussusception is second only to pyloric stenosis as a causeof obstruction in children; it is the most common cause ofsmall bowel obstruction in children and occurs in at least 56children/100,000/year in the USA [1]. Viruses are associ-ated with intussusception, particularly adenovirus [1].Intussusception occurs most commonly in infants aged 5–9 months (67% occur by age 1 year) [2]. The classic triad ofcolicky abdominal pain, vomiting, and bloody stools ispresent in less than 25% children [3–5]. Delay in diagnosisand treatment is not uncommon, making enema reductionless successful, bowel resection more likely, and death dueto bowel ischemia possible [2, 6–8]. There were 323intussusception-associated deaths in American infantsreported to the Centers for Disease Control (CDC) between1979 and 1997.Abdominal radiographsThe presence of a curvilinear mass within the course of thecolon (the crescent sign), particularly in the transversecolon just beyond the hepatic flexure, is a nearly patho-gnomonic sign of intussusception. The absence of bowelgas in the ascending colon is one of the most specific signsof intussusception on radiographs [9]. However, abdominalradiographs have low sensitivity (45%) and therefore arenot recommended to diagnose intussuception.The increasing role of ultrasoundIntussusception can be reliably diagnosed when a ‘donut’,‘target’ or ‘pseudokidney’ sign is seen with sonography[10–13].The optimal US technique in this population iswell described and includes the use of a linear transducer[11–15]. US also plays a role in the evaluation ofreducibility of the intussusception, the presence of apathologic lead point (PLP) mass, intussusception limitedto small bowel, the diagnosis or exclusion of residual

CT with a Computer-Simulated Dose Reduction Technique for Detection of Pediatric Nephroureterolithiasis: Comparison of Standard and Reduced Radiation Doses

OBJECTIVE The purpose of this study was to compare the diagnostic capabilities of standard- and reduced-dose CT in the detection of nephroureterolithiasis in children. MATERIALS AND METHODS Forty-five patients 20 years old or younger divided into two groups weighing 50 kg or less and more than 50 kg underwent unenhanced 16-MDCT in the evaluation of acute flank pain. An investigational computer-simulated tube current reduction tool was used to produce additional 80- and 40-mA examination sets (total number of image sets=135). Three independent blinded readers ranked random images for stones (confidence scale, 1-5, least to most), hydronephrosis, noise-based image quality, and presence of nonrenal lesions. RESULTS Compared with the standard tube current used for the original CT scans, there was no significant reduction (p=0.37) in detection of renal stones at the 80-mA setting (mean dose reduction, 67%; range, 43-81%); and at the 40-mA setting (mean dose reduction, 82%; range, 72-90%), the detection rate was significantly lower (p=0.05). At the 40-mA setting, there was no significant difference among the children weighing 50 kg or less (p=0.4). Detection of ureteral stones and hydronephrosis was not significantly different at 80 and 40 mA; however, disease frequency was low, and no definite conclusion can be made. CONCLUSION Simulated dose reduction is a useful tool for determining diagnostic thresholds for MDCT detection of renal stones in children. Use of the 80-mA setting for all children and 40 mA for children weighing 50 kg or less does not significantly affect the diagnosis of pediatric renal stones.

Medical radiation exposure in children with inflammatory bowel disease estimates high cumulative doses

Background: Children with inflammatory bowel disease (IBD) undergo imaging using ionizing radiation and may be exposed to high cumulative radiation. We hypothesized that children with IBD have high exposure to radiation from medical imaging. Methods: An Institutional Review Board (IRB)‐approved retrospective chart review from 2002–2008 was performed on all patients with IBD. Radiographic studies performed were recorded and exposure for each study was estimated. Results: A total of 117 children with IBD (86 Crohns disease [CD], 31 ulcerative colitis [UC]) were evaluated. The median current exposure was 15.1 mSv in CD and 7.2 mSv in UC (P = 0.005). Computed tomography (CT) scan and small bowel follow‐through (SBFT) were responsible for 43% and 36% of all radiation exposures, respectively. The rate of radiation was higher in CD compared to UC (4.3 versus 2.2 mSv/yr). In CD, the rate of exposure was highest in the first 3 years of diagnosis (8.2 mSv/yr), and no different between the 3–5 year follow‐up and 5+ year follow‐up groups (3.8 versus 4.3 mSv/yr). Using the annual dose rate in those followed for more than 3 years, an estimated 47 out of 78 (60%) children (40 CD, 7 UC) would exceed 50 mSv by 35 years of age. Conclusions: Radiation exposure from medical imaging is high in a subset of children diagnosed with IBD. Estimation of radiation exposure at age 35 suggests a significant portion of children with IBD will have high radiation exposure in their lifetime. Nonionizing imaging such as magnetic resonance imaging (MRI) and ultrasound should be offered to children with IBD as an alternative to current imaging that employs radiation. Inflamm Bowel Dis 2011

Evidence-based diagnosis of malrotation and volvulus

Malrotation is a congenital, abnormal rotation of the bowel, usually both small and large bowel, within the peritoneal cavity. There is accompanying abnormal fixation by mesenteric bands, or there is absence of fixation of portions of the bowel and this leads to an increased risk of acute or chronic volvulus and bowel necrosis. Intestinal malrotation covers the entire range of intestinal anomalies from readily apparent omphalocele in the newborn to asymptomatic “nonrotation” of the large and small bowel in an adult. While the large majority becomes clinically symptomatic in the neonate, an important minority occur beyond infancy and without the typical clinical presentation of bilious vomiting [1]. The goal of initial bowel imaging is early detection (or exclusion) of malrotation to prevent volvulus and potentially life-threatening bowel ischemia. Additional imaging studies, particularly repeat UGI series or enema, may be performed to further characterize indeterminate results. Epidemiology