ABR Pediatric Radiology common mistakes
ABR Pediatric Radiology · Understand the traps and how to avoid them.
In an infant with macrocephaly and prominent extra-axial fluid, calling the fluid a subdural hematoma and raising concern for abuse before measuring the subarachnoid space and checking whether cortical veins cross the fluid.
Benign enlargement of the subarachnoid spaces is common in infancy, and subdural collections displace bridging veins rather than being crossed by them; anchoring on abuse prevents a calm anatomic assessment.
What to do instead
Measure the extra-axial space, compare supra- and infratentorial compartments, look for crossing cortical veins, and use US or MRI to distinguish subarachnoid from subdural fluid before assigning mechanism.
Giving one diagnosis for a posterior fossa mass in a child without using age, location within the cerebellum/fourth ventricle, margins, calcification, and enhancement to rank medulloblastoma, ependymoma, and pilocytic astrocytoma.
Candidates often rely on pattern recognition from adult tumors or a single memorable case and skip the systematic feature extraction that separates these common pediatric tumors.
What to do instead
State the age group, exact compartment and ventricle relationship, margin, calcification, hemorrhage, and enhancement pattern, then give a ranked differential with the features that favor or argue against each entity.
Calling a normal thymus a mediastinal mass in a young child and recommending biopsy or further imaging solely because the mediastinum looks wide.
The thymus can be large and lobulated in infants and young children, and unfamiliarity with normal thymic variants leads to overdiagnosis of lymphoma or teratoma.
What to do instead
Check for a sail sign, lack of mass effect on adjacent vessels and airway, normal thymic shape, and stability on comparison; when needed, use US or MRI to confirm normal thymic tissue rather than proceeding to biopsy.
Discharging a neonate with bilious vomiting after a normal abdominal radiograph without requesting an upper GI contrast study.
Malrotation with volvulus can produce a normal or nonspecific plain radiograph, and the time-critical nature of bowel ischemia makes a normal film falsely reassuring.
What to do instead
Treat bilious vomiting in a neonate as a surgical emergency: obtain an upper GI series unless contraindicated, discuss immediately with pediatric surgery, and do not let a normal radiograph end the workup.
Applying adult lymph node size thresholds to a child and calling normal reactive mesenteric nodes pathologic, or ignoring suspicious nodes because they are small.
Normal mesenteric and cervical nodes are common in children, and adult cutoff values do not account for age-related lymphoid hyperplasia or for malignant nodes that can be small.
What to do instead
Use pediatric size criteria, assess node shape, clustering, loss of fatty hilum, necrosis, and associated bowel or organ findings, and correlate with symptoms and laboratory markers before labeling nodes pathologic.
Diagnosing a buckle fracture from a single radiographic view and not obtaining orthogonal views or a contralateral comparison when the cortex is subtly irregular.
Torus fractures are subtle, and overlapping bones or projectional effects on one view can mimic or hide a fracture; candidates often stop after the first abnormal-looking image.
What to do instead
Obtain at least two orthogonal views, inspect the cortex circumferentially at the metaphysis, and use contralateral comparison or follow-up imaging when the finding remains equivocal.
Calling a solitary lytic bone lesion in a child malignant without assessing margin, zone of transition, periosteal reaction, and age-specific differential including infection, Langerhans cell histiocytosis, and benign cysts.
Pediatric lytic lesions span benign and aggressive entities, and jumping to malignancy without describing aggressiveness features produces both false alarms and missed aggressive lesions.
What to do instead
Describe the lesion's margin, sclerotic rim, periosteal reaction, matrix, and soft-tissue component, give an age- and location-based differential, and recommend MRI, labs, or biopsy only when the aggressiveness assessment supports it.
Planning embolization or sclerotherapy for a vascular anomaly without first classifying it as an infantile hemangioma, venous malformation, lymphatic malformation, or arteriovenous malformation.
Treatment differs fundamentally by lesion type, and candidates sometimes treat any vascular-looking lesion as a hemangioma or as an AVM, risking ineffective or harmful intervention.
What to do instead
Use the ISSVA classification, obtain a focused clinical history and lesion imaging, confirm flow characteristics and tissue involvement, and present the case in a multidisciplinary vascular anomalies conference before intervention.
Interpreting physiologic thymic, brown fat, growth plate, tonsillar, or urinary FDG uptake in a child as metastatic or recurrent disease.
Pediatric biodistribution differs from adults, and normal structures such as the thymus and growth plates can be intensely avid; unfamiliarity with these patterns causes false-positive interpretations.
What to do instead
Know age-specific physiologic FDG distribution, correlate uptake with CT or MRI anatomy, use appropriate prep and sedation, and repeat or fuse imaging when a physiologic pattern is suspected before calling malignancy.
Ordering or protocoling a pediatric CT with adult mA and kV settings without checking prior imaging or considering ultrasound or MRI first.
Habit and time pressure lead to adult protocols being applied to children, and candidates may not review prior studies before adding another radiation exposure.
What to do instead
Use size-based pediatric CT protocols, review prior imaging and outside studies, choose ultrasound or MRI when diagnostic, and document the radiation justification and dose-reduction steps in the report.