What’s new in Pediatric Imaging – June 2021

3 years ago




Extracardiac imaging findings in COVID-19-associated multisystem inflammatory syndrome in children. 

Felon III EP, Chen S, Ruzal-Shapiro CB, et al.

Pediatric Radiology (2021) 51: 831-839.


Question(s) What are the extra-cardiac radiologic findings of MIS-C in children and young adults? 

Design Retrospective study from April to July 2020 

Setting Single-center 

Participants 47 patients (mean age 8.4 years, range 1.3-20 years) with a total of 45 CXRs, 8 AXRs, 13 abdominal US or MRIs, 2 neck US, 4 brain MRIs. 

Outcomes Extra-cardiac radiologic findings 

Results Most common chest radiographic finding were pulmonary opacities (60%), followed by peri-bronchial thickening (58%) and then normal chest radiographs. The most common extrapulmonary findings was small-volume ascites (54%), followed by RLQ bowel wall thickening (23%), gallbladder wall thickening (23%), and lymphadenopathy (cervical and abdominal). The neurologic findings included papilledema and bilateral parieto-occipital signal abnormalities.  

Commentary The study demonstrates the common radiologic findings in patients with MIS-C, which are nonspecific as they overlap with features of other disease entities, such as Kawasaki disease. The small sample size was a limitation of the study, particularly the few cross-sectional imaging studies.  


Ultrasound for the diagnosis of malrotation and volvulus in children and adolescents: a systematic review and meta-analysis. 

Nguyen HN, Kulkarni M, Jose J, et al.

Arch Dis Child (2021) 0: 1-8. Epub ahead of print: [10 May 2021].

doi:10.1136/ archdischild-2020-321082. 

Question(s) What is the diagnostic accuracy of US in the diagnosis of malrotation with or without volvulus in children and adolescents in comparison to the reference standards (surgery, UGI, CT, MRI)?  

Design Systematic review and meta-analysis (databases searched include Ovid-MEDLINE, Embase, Scopus, CINAHL, Cochrane Library) 

Participants 17 cohort or cross-sectional studies (2257 participants) that evaluated the diagnostic performance of US for diagnosis of midgut malrotation with or without volvulus in children (0-21 years of age) 

Outcomes Summary sensitivity and specificity for the use of US with subgroup analysis and meta-regression 

Results Moderate certainty evidence suggests excellent diagnostic accuracy (summary sensitivity 94% and summary specificity 100%) for US detection of malrotation. While there was no significant difference between the sensitivity of UGI and US, the meta-analysis showed statistically higher specificity for US than UGI (p=0.04). 

Commentary The authors demonstrated moderate certainty evidence for the use of abdominal US for diagnosing midgut malrotation with and without volvulus. The limitations included substantial heterogeneity among the included studies. Further sonographic studies exploring the technique and signs are encouraged as there was an insufficient number of studies for meta-regression analysis for some of the sonographic signs. 




Radiation dose reduction during intra-arterial chemotherapy for retinoblastoma: a retrospective analysis of 96 consecutive pediatric interventions using five distinct protocols 

Monroe EJ, Chick JFB, Stacey AW et al.

Pediatric Radiology (2021) 51: 649-657.


Question(s) What is the effect of different intra-procedural techniques on radiation exposure during intra-arterial chemotherapy (IAC)? 

Design Retrospective study of an institution’s experience with IAC from 2015 to 2020 based on 5 imaging protocol types (A, B, C, D, and E) using a combination of uniplanar vs. multiplanar imaging and digital subtraction angiography (DSA) versus a roadmap angiographic technique. Sequence elimination, consolidation from biplane to lateral-only imaging, and replacement of DSA by roadmap angiography each constituted a protocol change. 

Setting Single-center 

Participants 24 patients undergoing IAC for retinoblastoma (a total of 96 consecutive treatments and 109 ocular treatments were performed) 

Outcomes The primary outcome was radiation exposure (defined as fluoroscopy time and air kerma); secondary outcomes include technical success (catheterization of the ophthalmic or meningolacrimal artery with complete delivery of chemotherapy) and procedural adverse events (as defined by SIR guidelines). 

Results Mean fluoroscopy time was 6.4 ± 6.2 min (range 0.7-31.1 min), and mean air kerma was 36.2 ± 52.2 mGy (range 1.4-215 mGy). Protocol E included 3 lateral-only sequences using only negative roadmap angiogram and had the shortest mean fluoroscopy time (3.1 ± 3.2 min) and lowest mean air kerma (5.4 ± 4.2 mGy). Radiation exposure was also analyzed over time, which demonstrated a reduction in mean fluoroscopy time (by 66.7%) and mean air kerma (by 94.1%) when comparing the last quartile to the first quartile. Ocular technical success rate was 97.2% (failed treatments were repeated within 1 week and were subsequently successful). There were 2 major (1.8%) complications, which included ophthalmic artery vasospasm that was unresponsive to vasodilators to allow infusion of chemotherapy. There were 4 minor (3.7%) complications, including bronchospasm (responsive to albuterol), and common femoral artery vasospasm with weak pulses (responsive to leg warming and heparin drip).  

Commentary The authors showed that revisions to procedural imaging techniques can be aimed toward ALARA (As Low As Reasonably Achievable) to dramatically reduce radiation exposure during IAC for retinoblastoma without adversely affecting technical success or safety. It was particularly interesting that none of the 3 providers (2 neurointerventional radiologists and 1 pediatric interventional radiologist) had specific procedural experience of IAC for retinoblastoma prior to this series. The retrospective nature of the study was a limitation because it did not allow for consensus protocols to be formed prospectively; the changes were phased in over time based on operator discretion, observed dose reductions, and increased experience/comfort with the procedure. 


Use of angioembolization in pediatric polytrauma patients with blunt splenic injury 

Swendiman R, Abramov A, Fenton S, et al,

J. Pediatr Surg. 2021, journal pre-proof,


Question: What are the outcomes of angioembolization (AE) after pediatric blunt splenic trauma? Do they differ between adult and pediatric trauma centers? 

Design: Retrospective cohort study over 5 years (2010-2015) 

Setting: Multi-institutional query of the National Trauma Data Bank  

Participants: 14,027 children with blunt splenic trauma, 514 undergoing AE 

Outcomes: Differences in outcomes of AE and splenic trauma between pediatric trauma centers (PTC) and adult trauma centers (ATC). Measured outcomes included splenectomy and mortality.  

Main Result: Patients who presented to PTC were younger (12.1 years versus 14.8 years) and less likely to be in shock (33.3% versus 41.9%) than those that presented to ATC. The patients at ATC also had more severe splenic trauma (77.6% grade 3 injury or greater versus 51.9%). Of the 14,027 children with isolated splenic trauma, 514 underwent AE (3.7%). Patients who underwent AE had lower rates of splenectomy (OR 0.16). However, there was no difference in mortality between PTC and ATC in high grade injuries.  

Commentary: Overall, patients with blunt splenic trauma who underwent AE had lower rates of splenectomy without difference in mortality rate. However, patients who presented to ATC were more likely to undergo intervention (AE or splenectomy) than patients who presented to PTC. This may be due in part to demographics of the patients as ATC patients were older and sustained more severe injuries. It may also be in part due to the propensity towards nonsurgical management of pediatric patients at dedicated pediatric hospitals. Therefore, overall, pediatric trauma centers have a higher splenic salvage rate. 




Accuracy of CT for measuring femoral neck anteversion in children with developmental dislocation of the hip verified by using 3D printing technology.  

Cai Z, Piao C, Zhang T, et al.

Journal of Orthopaedic Surgery and Research (2021) 16;256: 1-8.


Question(s) What is the accuracy of CT methods in measuring the femoral neck anteversion angle (FNA) using 3D printing technology for verification and what is the clinical value? 

Design Retrospective study 

Setting Single-center 

Participants 68 children with unilateral DDH 

Outcomes 2D-CT and 3D-CT with FNA measurements with repeat of each measurement after 3 months respectively, compared to FNA measurements made by the 3D-printed femur (3D-PF) model. 

Results FNA measurement results were statistically different between 2D-CT and 3D-CT (p=0.006) and also between 2D-CT and 3D-PF (p=0.007). There was no significant difference between the FNA measurements made on 3D-CT and 3D-PF (p=0.081). Additionally, consistency of intra- and inter-observers was poor on 2D-CT but was good on 3D-CT.  

Commentary Using the 3D-PF method for verification, the authors were able to confirm the accuracy and reliability of 3D-CT over 2D-CT for measuring the FNA. Limitations in the study include small sample size and lack of long-term follow-up. 


Pediatric discoid meniscus: can magnetic resonance imaging features coupled with clinical symptoms predict the need for surgery? 

Hesse D, Finlayson C, Gladstein A, et al.

Pediatr Radiol 2021, published online,


Question: Can MR features of intact discoid meniscus, along with clinical features, predict the need for surgery? 

Design: Retrospective cohort study over 11 years from 2008-2019  

Setting: Single Institution; Lurie Children’s Hospital, Chicago IL 

Participants: 71 patients less than 18 years old with MR showing intact discoid meniscus

Outcomes: MRI features of discoid meniscus including craniocaudal dimension, transverse dimension, transverse dimension to tibial plateau (TV:TP) ratio and increased intrameniscal signal. The clinical course was reviewed for knee pain, mechanical symptoms and treatment type.

Main Results: All 71 patients had lateral discoid meniscus and 7 had discoid meniscus of both knees for a total of 78 unique knees. 14 required operative management (18%). Patients who required surgery had significantly larger transverse dimensions (P=0.045) and TV:TP ratio greater than 0.47 (P=0.036) than nonsurgical patients. Differences in craniocaudal length were not statistically different. Other statistically significant predictors of surgical intervention were increased intrameniscal signal on MR and mechanical symptoms such as knee pain and locking.

Commentary: The best predictor for surgical treatment of discoid meniscus is mechanical symptoms such as knee locking or pain. However, this study shows that transverse dimensions, TV:TP ratio, and increased intrameniscal signal can also help predict surgery in the future. Perhaps TV:TP ratio is a better measurement as it takes into account the size of the patient’s knee. Limitations of this study include a small sample size and the time after follow up; it does not take into account any surgery that patients may have received as adults. Also, most patients with discoid meniscus initially present with tears and therefore these results may not be applicable to the majority of patients with a discoid meniscus. 


Prediction of high-grade hip joint effusion with simple radiographs in children: a comparative study with magnetic resonance imaging. 

Cha Y, Kang MS, and Park SS.

Pediatric Emergency Care (2021) 37;5: e255-e260.  

Question(s) What is the predictive value of asymmetric joint space widening on radiographs for the presence of hip joint effusion in children with unilateral hip pain or limping? 

Design Retrospective study from 2000 to 2017 

Setting Single-center 

Participants 68 patients (age 6 to 17 years) who underwent radiographs and MRI 

Outcomes Measurements on radiographs (superior gap, medial gap, and distance between the teardrops), hip effusion grade on MRI (0 = none, 1 = minimal, 2 = around the femoral head, and 3 = distention of capsular recesses), specificity and sensitivity of hip radiographs and MRI. A predictive model was created using recursive partitioning analysis (RPA, a statistical method) to determine the most effective dichotomizing cutoff values with regards to the difference of superior gap, difference of medial gap, difference of medial and superior gaps, difference ratio of superior gap, difference ratio of medial gap, and difference ratio of medial and superior gaps. Multivariate analysis was performed on sex and the difference ratio of medial and superior gaps were independently associated with high-grade hip joint effusion (grades 2 or 3). 

Results The specificity of radiographic prediction for joint effusion was 80%, while the sensitivity was low (40-50%). Regardless of sex, children with higher difference ratio of medial and superior gaps showed the highest probability of high-grade joint effusion. Male children with lower difference ratio showed moderate probability and female children with lower difference ratio showed the lowest probability of high-grade joint effusion.  

Commentary The authors concluded that for children age 6 years and older, asymmetric joint space widening on radiographs has high specificity for the presence of a high-grade joint effusion, and further evaluation with US or MRI would be warranted. However, a major limitation of the study is that low-grade effusions or bilateral hip joint effusions may be missed based on this predictive model. Selection bias was also present in this study as patients who had both radiographs and MRI had more severe clinical symptoms or abnormal laboratory values. Additionally, patients who were uncooperative (i.e., younger than age 6 years) or had asymmetric positioning on radiographs were excluded from the study entirely, so the results cannot be generalized to these other groups. 


Rate of resident recognition of nonaccidental trauma: how well do residents perform? 

Sharma P, Rajderkar, Slater R, et al.

Pediatr Radiol 2021, published online,


Question: How good are radiology residents at detecting nonaccidental trauma (NAT) on call? 

Design: Wisdom in Diagnostic Imaging Emergent/Critical Care Radiology Simulation (WIDI SIM), a well-tested and proven simulation assessing resident preparedness. Study over 4 years (2014-2017). 

Setting: 29 radiology residency programs across the United States 

Participants: 675 radiology residents – 427 R1, 202 R2, 28 R3, 18 R4  

Outcomes: The ability of residents to independently identify findings consistent with NAT. Each year of testing the case/skeletal survey findings changed. 

Main Results:  The first year test required residents to identify metaphyseal corner and posterior rib fractures. 71% of residents correctly identified the findings, with higher percentages among more senior residents. The second year test required residents to identify a skull fracture with only at total of 20% of residents correctly reporting the finding. Year 3 required identification of fractures of different ages (ribs, femur) with 79% of residents correctly reporting the finding (again with better accuracy among senior residents). Finally the fourth year required identification of rib fractures of varying ages from a single AP chest radiograph. Only 10% of residents correctly reported the finding with the highest percentages among second year residents and the worst among fourth years. 

Commentary: Prompt and accurate identification of NAT is imperative and radiology plays an important role in the process. At many academic institutions, residents take independent overnight call and need to be familiar with signs of NAT. This study shows that residents, especially senior residents, can identify classic finds of NAT such as metaphyseal corner and posterior rib fractures. However, they do not perform as well when the findings are more subtle (skull fractures) or if they are present on studies such as routine chest radiographs that are not skeletal surveys or intended to primarily assess for NAT. This raises the concern that residents may not be able to recognize NAT as well as desired and there is likely a need for more rigorous training regarding recognizing NAT before and during independent call. 




Asymptomatic macrocephaly: to scan or not to scan 

Thomas C, Kolbe A, Binkovitz L, et al.

Pediatr Radiol, 2021, 51:811-821,


Question: What is the utility of screening head ultrasound (US) in asymptomatic infants with macrocephaly? What are clinical factors associated with significant US findings?

Design: 20 year retrospective study from January 1997 to June 2017 

Setting: Single Institution; Mayo Clinic, Department of Radiology, Rochester, MN 

Participants: 440 infants under 12 months undergoing head US for rapidly increasing head circumference 

Outcomes: Findings of head US and any associated significant pathology. Head circumference at birth and at time of ultrasound as well as any clinical signs and symptoms that could be attributed to an intracranial process as well as any CT and MR findings were also reviewed.
Main Results: Ultrasound reports were initially categorized as: normal (64%), incidental finding (31%), indeterminate but potentially significant (3.8%), or significant (1.4%). 34 cases classified as normal or incidental underwent additional imaging with minimally changed diagnoses – they remained either normal or incidental and no significant diagnosis was made. 17 infants were classified as indeterminate and 14 underwent subsequent imaging with 2 having subdural hemorrhage. All 8 cases characterized as significant underwent subsequent imaging – 2 had tumors that required resection, 2 had aqueductal stenosis requiring shunting, 3 had subdural hematomas with one requiring evacuation, and one had a large arachnoid cyst which was followed. Of the clinical factors studied, the only one statistically significant associated with findings was increased head circumference at birth. 

Commentary: The majority of screening US performed for asymptomatic macrocephaly will be normal. Significant pathology is also readily identified using head US. Therefore, head US and clinical follow up are reliable for detection or exclusion of relevant pathology.  For cases classified as indeterminate, follow up could be performed with either CT/MR or clinical follow up with head circumference measurements and symptom monitoring. Limitations of this study include its retrospective nature and that it could not be confirmed if patients subsequently received care at a different institution.  




Association of Clinical Guidelines and Decision Support with CT use in Pediatric Mild Traumatic Brain Injury 

Marin J, Rodean J, Mannix R, et al, 

J. Pediatr 2021, journal pre-proof,


Question:  Does having clinical guidelines (CG) and clinical decision support (CDS) in place reduce the rate of CT in the setting of traumatic brain injury (TBI). 

Design: Cross-sectional study involving over 4 years (2015-2019) 

Setting: Multi-institutional over 45 pediatric emergency departments in the Pediatric Hospital Information System  

Participants: 216,789 children with TBI 

Outcomes: The primary outcome was the association of CG and CDS with the use of head CT. Secondary outcomes included ED length of stay (LOS) and rates of 3 day ED revisits with admission rates with revisits. 

Main Results: of the 216,789 children with TBI, 20.3% (44,114) had head CTs. Of the 45 EDs studied, 17 (37.8%) had CG, 9 (20%) had CDS, and 19 (42%) had neither. The EDs that had either CG or CDS had lower odds of performing CT for TBI. EDs with CDS had a lower odds ratio (0.52) than EDs with CG (0.83). ED LOS and revisit rates did not differ among either groups. 

Commentary: This study demonstrates that the use of CG and CDS can help reduce the number of head CTs performed for TBI in children. However, this study was performed at dedicated pediatric hospitals familiar with evaluation and treatment of pediatric specific TBI. Therefore, implementation of CG and CSD may not be feasible at nonspecialized hospitals. Additionally, CG and CDS may not be standardized across institutions. Limitations of this study include limited clinical data and the rate of TBI could have been under represented as only patients with a primary diagnosis of TBI were included 

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