Daytime, evening, and overnight: the 24-h radiology cycle and impact on interpretative accuracy.

PURPOSE: To assess the influence of time of day when a study is interpreted on discrepancy rates for common and advanced studies performed in the acute community setting. METHODS: This retrospective study used the databank of a U.S. teleradiology company to retrieve studies between 2012 and 2016 with a preliminary report followed by a final report by the on-site client hospital. Neuroradiology, abdominal radiology, and musculoskeletal radiology studies were included. Teleradiologists were fellowship trained in one of these subspecialty areas. Daytime, evening, and overnight times were defined. Associations between major and minor discrepancies, time of day, and whether the study was common or advanced were tested with significance set at p = .05. RESULTS: A total of 5,883,980 studies were analyzed. There were 8444 major discrepancies (0.14%) and 17,208 minor discrepancies (0.29%). For common studies, daytime (0.13%) and evening (0.13%) had lower major discrepancy rates compared to overnight (0.14%) (daytime to overnight, RR = 0.57, 95%CI: 0.45, 0.72, p < 0.01 and evening to overnight, RR = 0.57, 95%CI: 0.49,0.67, p < 0.01). Minor discrepancy rates for common studies were decreased for evening (0.29%) compared to overnight (0.30%) (RR = 0.89, 95%CI: 0.80,0.99, p = 0.029). For advanced studies, daytime (.15%) had lower major discrepancy rates compared to evening (0.20%) and overnight (.23%) (daytime to evening, RR = 0.77, 95%CI: 0.61, 0.97, p = 0.028 and daytime to overnight, RR = 0.66, 95%CI: 0.50, 0.87, p ≤ 0.01). CONCLUSION: Significantly higher major discrepancy rates for studies interpreted overnight suggest the need for radiologists to exercise greater caution when interpreting studies overnight and may require practice management strategies to help optimize overnight work conditions. The lower major discrepancy rates on advanced studies interpreted during the daytime suggest the need for reserving advanced studies for interpretation during the day when possible.

Starting an Emergency Radiology Division: Scheduling and Staffing, Compensation, and Equity and Parity.

Establishing an emergency radiology division in a practice that has long-standing patterns of operational routines comes with both challenges and opportunities. In this article, considerations around scheduling and staffing, compensation, and equity and parity are provided with supporting literature references. Furthermore, a panel of experts having established, grown and managed emergency radiology divisions in North America and Europe share their experiences through a question and answer format.

Traumatic abdominal wall hernias in the pediatric population: a 13-year institutional review.

BACKGROUND: Pediatric traumatic abdominal wall hernias are rare but potentially devastating injuries. Although classically considered to be caused by handlebar injuries from bicycle accidents, our anecdotal experience suggests pediatric traumatic abdominal wall hernias are far more likely to occur following road traffic accidents and have a high association with other significant intra-abdominal injuries. OBJECTIVE: The purpose of this study was to determine the frequency, mechanisms of injury, and associated injuries of traumatic abdominal wall hernias in the pediatric population. MATERIALS AND METHODS: This is a retrospective observational cohort study from two large urban level 1 trauma centers. Institutional trauma registries were queried from January 1, 2008, to December 31, 2020, for patients under 18 years of age diagnosed with traumatic abdominal wall hernias, excluding those without initial abdominopelvic CT imaging. Finalized CT reports and images were reviewed to confirm the presence of a traumatic abdominal wall hernia and document any associated secondary injuries. The medical record was reviewed to extract pertinent physical findings, interventions performed, and outcomes. Injury Severity Score (ISS) for each patient was calculated by the trauma registrar. RESULTS: A total of 19 patients with TAWH met inclusion criteria, with an overall frequency of 0.095% and a mean age of 10.6 years (range 3-17). Eleven patients were male (57.9%) with a mean ISS of 18.6 (range 1-48, including 63.2% with ISS > 15). The most common mechanism of injury was motor vehicle collision (N = 11, 57.9%) followed by bicycle accident (N = 3, 15.8%). A total of 17 (89.5%) had associated injuries, including 11 (57.9%) with intestinal injuries, 5 (26.3%) with pelvic fractures, 4 (21.1%) with femur fractures, 3 (15.8%) with splenic injuries, 3 (15.8%) with kidney injuries, and 3 (15.8%) with Chance fractures of the lumbar spine. All patients required surgery for the traumatic abdominal wall hernias and associated injuries. CONCLUSION: Pediatric traumatic abdominal wall hernias are more likely to be seen following motor vehicle collisions, with a majority (89.5%) having associated injuries, most frequently to the bowel (57.9%). Handlebar injuries were seen in a minority of patients (15.8%) and were less likely to be associated with additional injuries. CLINICAL IMPACT: Pediatric patients with a traumatic abdominal wall hernia on admission CT should be thoroughly evaluated for bowel injuries, especially in the setting of a motor vehicle collision.

ACR Appropriateness Criteria® Acute Pyelonephritis: 2022 Update.

Acute pyelonephritis (APN) is a severe urinary tract infection (UTI) that has the potential to cause sepsis, shock, and death. In the majority of patients, uncomplicated APN is diagnosed clinically and is responsive to treatment with appropriate antibiotics. In patients who are high risk or when treatment is delayed, microabscesses may coalesce to form an acute renal abscess. High-risk patients include those with a prior history of pyelonephritis, lack of response to therapy for lower UTI or for APN, diabetes, anatomic or congenital abnormalities of the urinary system, infections by treatment-resistant organisms, nosocomial infection, urolithiasis, renal obstruction, prior renal surgery, advanced age, pregnancy, renal transplant recipients, and immunosuppressed or immunocompromised patients. Pregnant patients and patients with renal transplants on immunosuppression are at an elevated risk of severe complications. Imaging studies are often requested to aid with the diagnosis, identify precipitating factors, and differentiate lower UTI from renal parenchymal involvement, particularly in high-risk individuals. Imaging is usually not appropriate for the first-time presentation of suspected APN in an uncomplicated patient. The primary imaging modalities used in high-risk patients with suspected APN are CT, MRI, and ultrasound, although CT was usually not appropriate for initial imaging in a pregnant patient with no other complications. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Suspected Retroperitoneal Bleed.

The initial diagnosis of retroperitoneal bleeding can be challenging by physical examination and clinical presentation. Prompt imaging can make the diagnosis and be lifesaving. When selecting appropriate imaging for these patient's, consideration must be made for sensitivity and ability to image the retroperitoneum, as well as speed of imaging.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

American Society of Emergency Radiology Multicenter Blunt Splenic Trauma Study: CT and Clinical Findings.

Background Treatment of blunt splenic trauma (BST) continues to evolve with improved imaging for detection of splenic vascular injuries. Purpose To report on treatments for BST from 11 trauma centers, the frequency and clinical impact of splenic vascular injuries, and factors influencing treatment. Materials and Methods Patients were retrospectively identified as having BST between January 2011 and December 2018, and clinical, imaging, and outcome data were recorded. Patient data were summarized descriptively, both overall and stratified by initial treatment received (nonoperative management [NOM], angiography, or surgery). Regression analyses were used to examine the primary outcomes of interest, which were initial treatment received and length of stay (LOS). Results This study evaluated 1373 patients (mean age, 42 years ± 18; 845 men). Initial treatments included NOM in 849 patients, interventional radiology (IR) in 240 patients, and surgery in 284 patients. Rates from CT reporting were 22% (304 of 1373) for active splenic hemorrhage (ASH) and 20% (276 of 1373) for contained vascular injury (CVI). IR management of high-grade injuries increased 15.6%, from 28.6% (eight of 28) to 44.2% (57 of 129) (2011-2012 vs 2017-2018). Patients who were treated invasively had a higher injury severity score (odds ratio [OR], 1.04; 95% CI: 1.02, 1.05; P < .001), lower temperature (OR, 0.97; 95% CI: 0.97, 1.00; P = .03), and a lower hematocrit (OR, 0.96; 95% CI: 0.93, 0.99; P = .003) and were more likely to show ASH (OR, 8.05; 95% CI: 5.35, 12.26; P < .001) or CVI (OR, 2.70; 95% CI: 1.64, 4.44; P < .001) on CT images, have spleen-only injures (OR, 2.35; 95% CI: 1.45, 3.8; P < .001), and have been administered blood product for fewer than 24 hours (OR, 2.35; 95% CI: 1.58, 3.51; P < .001) compared with those chosen for NOM, after adjusting for key demographic and clinical variables. After adjustment, factors associated with a shorter LOS were female sex (OR, 0.84; 95% CI: 0.73, 0.96; P = .009), spleen-only injury (OR, 0.72; 95% CI: 0.6, 0.86; P < .001), higher admission hematocrit (OR, 0.98; 95% CI: 0.6, 0.86; P < .001), and presence of ASH at CT (OR, 0.74; 95% CI: 0.62, 0.88; P < .001). Conclusion Contained vascular injury and active splenic hemorrhage (ASH) were frequently reported, and rates of interventional radiologic management increased during the study period. ASH was associated with a shorter length of stay, and patients with ASH had eight times the odds of undergoing invasive treatment compared with undergoing nonoperative management. © RSNA, 2021 See also the editorial by Patlas in this issue.

ACR Appropriateness Criteria® Seizures and Epilepsy.

Seizures and epilepsy are a set of conditions that can be challenging to diagnose, treat, and manage. This document summarizes recommendations for imaging in different clinical scenarios for a patient presenting with seizures and epilepsy. MRI of the brain is usually appropriate for each clinical scenario described with the exception of known seizures and unchanged semiology (Variant 3). In this scenario, it is unclear if any imaging would provide a benefit to patients. In the emergent situation, a noncontrast CT of the head is also usually appropriate as it can diagnose or exclude emergent findings quickly and is an alternative to MRI of the brain in these clinical scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Differences in Outcomes Associated With Individual Radiologists for Emergency Department Patients With Headache Imaged With CT: A Retrospective Cohort Study of 25,596 Patients.

OBJECTIVE. The purpose of this study was to determine whether diagnostic radiologists impart variation into resource use and patient outcomes in emergency department (ED) patients undergoing CT for headache. MATERIALS AND METHODS. This was a single-institution retrospective quality assurance cohort study of 25,596 unique adult ED patients undergoing head CT for headache from January 2012 to October 2017. CT examinations were interpreted by 55 attending radiologists (25 neuroradiologists, 30 radiologists of other specialties) who each interpreted a mean of 1469.8 ± 787.9 CT examinations. Risk adjustment for variables thought to influence outcome included baseline risk (demographics, Elixhauser comorbidity score), clinical factors (vital signs, ED triage and pain scores, laboratory data, hydrocephalus, prior intracranial hemorrhage, neurosurgical consultation within last 12 months), and system factors (time of CT, physician experience, neuroradiology training). Multivariable models were built to analyze the effect of individual radiologists on subsequent outcomes. Any p value less than 0.007 was considered significant after Bonferroni correction. RESULTS. The study found 57.5% (14,718/25,596) of CT interpretations were performed by neuroradiologists, and most patients (98.1% [25,119/25,596]) had no neurosurgical history. After risk adjustment, individual radiologists were not an independent predictor of hospital admission (p = 0.49), 30-day readmission (p = 0.30), 30-day mortality (p = 0.14), or neurosurgical intervention (p = 0.04) but did predict MRI use (p < 0.001; odds ratio [OR] range among radiologists, 0.009-38.2), neurology consultation (p < 0.001; OR range, 0.4-3.2), and neurosurgical consultation (p < 0.001; OR range, 0.1-9.9). CONCLUSION. Radiologists with different skills, experience, and practice patterns appear interchangeable for major clinical outcomes when interpreting CT for headache in the ED, but their differences predict differential use of downstream health care resources. Resource use measures are potential quality indicators in this cohort.

Emergency Radiology: Current Challenges and Preparing for Continued Growth.

The escalation of imaging volumes in the emergency department and intensifying demands for rapid radiology results have increased the demand for emergency radiology. The provision of emergency radiology is essential for nearly all radiology practices, from the smallest to the largest. As our radiology specialty responds to the challenge posed by the triple threat of providing 24-7 coverage, high imaging volumes, and rapid turnaround time, various questions regarding emergency radiology have emerged, including its definition and scope, unique operational demands, quality and safety concerns, impact on physician well-being, and future directions. This article reviews the current challenges confronting the subspecialty of emergency radiology and offers insights into preparing for continued growth.

Unifying the Silos of Subspecialized Radiology: The Essential Role of the General Radiologist.

As radiology becomes increasingly subspecialized, conversations focus on whether the general radiologist is trending toward extinction. Current data indicate that the vast majority of graduating radiology residents now seek fellowship training. Practicing entirely within the narrow confines of one's fellowship subspecialty area, however, is uncommon, with recent data indicating that more than half of all radiologists spend the majority of their work effort as generalists. From the traditional concept of the generalist as the non-fellowship-trained radiologist who interprets everything to the multispecialty-trained radiologist to the emergency radiologist who is a subspecialist but reads across the traditional anatomic divisions, the general radiologist of today and the future is one who remains broadly skilled and equipped to provide a wide spectrum of radiologic services. The successful future of many practices of all types and the specialty as a whole will require ongoing collaborative partnerships that include both general and subspecialized radiologists. This review article highlights various scenarios in which general radiologists provide value to different types of radiology practices.

Novel Quality Indicators for Radiologists Interpreting Abdominopelvic CT Images: Risk-Adjusted Outcomes Among Emergency Department Patients With Right Lower Quadrant Pain.

OBJECTIVE: The purpose of this study was to determine whether individual radiologists are predictive of important relevant health outcomes among emergency department (ED) patients undergoing abdominopelvic CT for right lower quadrant pain. MATERIALS AND METHODS: This single-institution retrospective cohort study included 2169 patients undergoing abdominopelvic CT for right lower quadrant pain in the ED from February 1, 2012, through August 31, 2016. CT examinations were interpreted by 15 radiologists (four emergency, 11 abdominal) who each reported on more than 70 CT examinations in the cohort. After risk adjustment for covariates thought to influence outcome, including baseline risk (demographics, 30 Elixhauser comorbidities, number of previous ED visits), clinical factors (vital signs, triage and pain scores, laboratory data), and system factors (time of CT, resident involvement, attending physician experience), multivariable models were built to analyze the effect of individual radiologists on four important health outcomes: hospital admission (primary outcome), readmission within 30 days, abdominal surgery, and image-guided percutaneous aspiration or drainage. RESULTS: Radiologists had a mean experience of 14 years (range, 2-36 years) and read a mean of 145 CT examinations in the study cohort (range, 73-253 examinations). Unadjusted event rates across the 15 radiologists were 38-55% (admission), 11-21% (readmission), 10-26% (surgery), and 0-3% (aspiration or drainage). After risk adjustment, individual radiologists were not a significant multivariable predictor of hospital admission, readmission within 30 days, abdominal surgery, or image-guided abdominal percutaneous aspiration or drainage (all p > 0.05). CONCLUSION: Individual radiologists were indistinguishable both within group and between group by emergency and abdominal specialization for the prediction of major patient outcomes after abdominopelvic CT performed for right lower quadrant pain in the ED.

Recurrence of Colonic Diverticulitis: Identifying Predictive CT Findings-Retrospective Cohort Study.

Purpose To identify computed tomographic (CT) findings that are predictive of recurrence of colonic diverticulitis. Materials and Methods Institutional review board approval was obtained for this HIPAA-compliant, retrospective cohort study. Six abdominal fellowship-trained radiologists reviewed the CT studies of 440 consecutive subjects diagnosed with acute colonic diverticulitis between January 2004 and May 2008 to determine the involved segments, maximum wall thickness in the inflamed segment, severity of diverticulosis, presence of complications (abscess, fistula, stricture, or perforation), and severity of the inflammation. Electronic medical records were reviewed for a 5-year period after the patients' first CT study to determine clinical outcomes. Predictors of diverticulitis recurrence were assessed with univariate and multiple Cox proportional hazard regression models. Results Colonic diverticulitis most commonly involved the rectosigmoid (70%, 309 of 440) and descending (30%, 133 of 440) colon segments. Complicated diverticulitis was present in 22% (98 of 440) of patients. On the basis of the results of univariate analysis, significant predictors of diverticulitis recurrence were determined to be maximum colonic wall thickness in the inflamed segment (hazard ratio [HR], 1.07 per every millimeter of increase in wall thickness; P < .001), presence of a complication (HR, 1.75; P = .002), and subjective severity of inflammation (HR, 1.36 for every increase in severity category; P value for linear trend = .003). The difference in maximum wall thickness in the inflamed segment (HR, 1.05 per millimeter; P = .016) and subjective inflammation severity (HR, 1.29 per category; P = .018)remained statistically significant in a Cox multiple regression model. Conclusion Maximum colonic wall thickness and subjective severity of acute diverticulitis allow prediction of recurrent diverticulitis and may be useful for stratifying patients according to the need for elective partial colectomy. © RSNA, 2017 Online supplemental material is available for this article.

MR Imaging of Pelvic Emergencies in Women.

MR imaging is a useful adjunct imaging modality for evaluating women presenting with acute lower abdominal/pelvic pain who have negative or inconclusive sonographic findings. In pregnant women, although obstetric complications are of prime concern, gastrointestinal pathologies also warrant careful attention, and MR imaging is often useful in refining the diagnosis. In nonpregnant women, gynecologic pathologies and gastrointestinal pathologies are of major concern, and may necessitate evaluation with MR imaging. Knowledge of imaging features in the appropriate clinical setting helps in early and accurate diagnosis, enabling timely management for better clinical outcomes.

Neurovascular emergencies: imaging diagnosis and neurointerventional treatment.

Neurovascular emergencies, consisting of acute ischemic stroke, non-traumatic aneurysmal subarachnoid hemorrhage, arteriovenous malformation, dural arteriovenous fistula, and carotid- cavernous fistula, can have an acute presentation to the emergency department. Radiologists should have an understanding of these processes and their imaging findings in order to provide a prompt and accurate diagnosis. Neurointerventional radiology plays a critical role in providing additional diagnostic information and potentially curative treatment. Understanding the grading scales used to evaluate and prognosticate these neurovascular emergencies can help expedite management for best possible patient outcomes.

A report on the Academic Emergency Medicine 2015 consensus conference "Diagnostic imaging in the emergency department: a research agenda to optimize utilization".

In May 2015, the Academic Emergency Medicine consensus conference "Diagnostic imaging in the emergency department: a research agenda to optimize utilization" was held. The goal of the conference was to develop a high-priority research agenda regarding emergency diagnostic imaging on which to base future research. In addition to representatives from the Society of Academic Emergency Medicine, the multidisciplinary conference included members of several radiology organizations: American Society for Emergency Radiology, Radiological Society of North America, the American College of Radiology, and the American Association of Physicists in Medicine. The specific aims of the conference were to (1) understand the current state of evidence regarding emergency department (ED) diagnostic imaging utilization and identify key opportunities, limitations, and gaps in knowledge; (2) develop a consensus-driven research agenda emphasizing priorities and opportunities for research in ED diagnostic imaging; and (3) explore specific funding mechanisms available to facilitate research in ED diagnostic imaging. Through a multistep consensus process, participants developed targeted research questions for future research in six content areas within emergency diagnostic imaging: clinical decision rules; use of administrative data; patient-centered outcomes research; training, education, and competency; knowledge translation and barriers to imaging optimization; and comparative effectiveness research in alternatives to traditional computed tomography use.

Renal trauma: imaging evaluation and implications for clinical management.

Severe renal injuries are usually associated with multisystem injuries, may require interventional radiology to control hemorrhage and improve the chances for renal salvage, and are more likely to fail nonoperative management. However, most renal injuries are mild in severity and successfully managed conservatively. The AAST classification is the most widely used system to describe renal injuries and carries management and prognostic implications. CT with intravenous contrast is the imaging test of choice to assess for renal injuries. Contrast extravasation indicating active bleeding should be mentioned as its presence is predictive for failure of nonoperative management. Radiologists play a critical role in identifying renal injuries and should make every effort to describe renal injuries according to the AAST grading scheme to better inform the surgeon's management decisions.

Equivocal Pediatric Appendicitis: Unenhanced MR Imaging Protocol for Nonsedated Children-A Clinical Effectiveness Study.

PURPOSE: To determine retrospectively the clinical effectiveness of an unenhanced magnetic resonance (MR) imaging protocol for evaluation of equivocal appendicitis in children. MATERIALS AND METHODS: Institutional review board approval was obtained. Pediatric patients (≤18 years old) underwent unenhanced MR imaging and contrast material-enhanced computed tomography (CT) of the appendix between December 2013 and November 2014 and December 2012 and November 2013, respectively, within 24 hours after an abdominal ultrasonographic examination with results equivocal for appendicitis. Pertinent MR imaging and CT reports were reviewed for visibility of the appendix, presence of appendicitis and appendiceal perforation, and establishment of an alternative diagnosis. Surgical reports, pathologic reports, and 30-day follow-up medical records were used as reference standards. Diagnostic performance with MR imaging and CT was calculated with 95% confidence intervals (CIs) for diagnosis of appendicitis and appendiceal perforation. The Fisher exact test was used to compare proportions; the Student t test was used to compare means. RESULTS: Diagnostic performance with MR imaging was comparable to that with CT for equivocal pediatric appendicitis. For MR imaging (n = 103), sensitivity was 94.4% (95% CI: 72.7%, 99.9%) and specificity was 100% (95% CI: 95.8%, 100%); for CT [n = 58], sensitivity was 100% (95% CI: 71.5%, 100%), specificity was 97.9% (95% CI: 88.7%, 100%). Diagnostic performance with MR imaging and CT also was comparable for detection of appendiceal perforation, with MR imaging (n = 103) sensitivity of 90.0% (95% CI: 55.5%, 99.8%) and specificity of 85.7% (95% CI: 42.1%, 99.6%) and CT (n = 58) sensitivity of 75.0% (95% CI: 19.4%, 99.4%) and specificity of 85.7% (95% CI: 42.1%, 99.6%). The proportion of examinations with identifiable alternative diagnoses was similar at MR imaging to that at CT (19 of 103 [18.4%] vs eight of 58 [13.8%], respectively; P = .52). The proportion of appendixes seen at MR imaging and at CT also was similar (77 of 103 [74.8%] vs 50 of 58 [86.2%], respectively; P = .11). CONCLUSION: Unenhanced MR imaging is sensitive and specific for the diagnosis of equivocal appendicitis in nonsedated pediatric patients.

Inter-radiologist agreement for CT scoring of pediatric splenic injuries and effect on an established clinical practice guideline.

BACKGROUND: The American Pediatric Surgical Association (APSA) advocates for the use of a clinical practice guideline to direct management of hemodynamically stable pediatric spleen injuries. The clinical practice guideline is based on the CT score of the spleen injury according to the American Association for the Surgery of Trauma (AAST) CT scoring system. OBJECTIVE: To determine the potential effect of radiologist agreement for CT scoring of pediatric spleen injuries on an established APSA clinical practice guideline. MATERIALS AND METHODS: We retrospectively analyzed blunt splenic injuries occurring in children from January 2007 to January 2012 at a single level 1 trauma center (n = 90). Abdominal CT exams performed at clinical presentation were reviewed by four radiologists who documented the following: (1) splenic injury grade (AAST system), (2) arterial extravasation and (3) pseudoaneurysm. Inter-rater agreement for AAST injury grade was assessed using the multi-rater Fleiss kappa and Kendall coefficient of concordance. Inter-rater agreement was assessed using weighted (AAST injury grade) or prevalence-adjusted bias-adjusted (binary measures) kappa statistics; 95% confidence intervals were calculated. We evaluated the hypothetical effect of radiologist disagreement on an established APSA clinical practice guideline. RESULTS: Inter-rater agreement was good for absolute AAST injury grade (kappa: 0.64 [0.59­0.69]) and excellent for relative AAST injury grade (Kendall w: 0.90). All radiologists agreed on the AAST grade in 52% of cases. Based on an established clinical practice guideline, radiologist disagreement could have changed the decision for intensive care management in 11% (10/90) of children, changed the length of hospital stay in 44% (40/90), and changed the time to return to normal activity in 44% (40/90). CONCLUSION: Radiologist agreement when assigning splenic AAST injury grades is less than perfect, and disagreements have the potential to change management in a substantial number of pediatric patients.