ABR common mistakes
ABR · Understand the traps and how to avoid them.
Reading the image or the vignette first and answering with the diagnosis, even when the final sentence asks 'which of the following is the most appropriate next step' or 'which management is indicated.'
Radiology training rewards pattern-to-diagnosis closure; the interrogative is the last thing read and gets skimmed under time pressure, so the strongest available answer (the diagnosis) is selected reflexively.
What to do instead
Read the last line of every stem first and underline the interrogative verb (diagnose vs. next step vs. contraindication vs. most likely cause). If the stem asks for management, physically cross out any answer option that is a diagnosis before evaluating the remainder.
Stopping the search as soon as one abnormality explains the clinical story, e.g., identifying the lobar consolidation and never checking the apices, bones, mediastinum, or the prior study.
Satisfaction of search and the anchoring effect of a clinically provided indication; the case arrives pre-labeled 'cough and fever,' so the eye is primed to terminate at the first finding.
What to do instead
Use a fixed anatomical sweep on every thoracic case (lung apices, pleura, hila/mediastinum, airways, bones/soft tissues, review areas) and always state in your own words what changed versus the comparison study before choosing an answer.
Assigning a BI-RADS category by lesion name rather than by the assessment table, for example calling a new spiculated mass or a cluster of pleomorphic calcifications 'probably benign, BI-RADS 3, short-interval follow-up.'
Three is mentally filed as 'probably fine,' and candidates conflate morphologically suspicious features with the small, explicitly defined set of entities that qualify for short-interval follow-up.
What to do instead
Memorize the assessment-to-management mapping and its entry criteria: BI-RADS 3 is reserved for specific probably benign findings (e.g., nonpalpable circumscribed oval mass, focal asymmetry, cluster of punctate calcifications) that are not new or enlarging. Suspicious morphology (spiculation, pleomorphic/fine-linear branching calcification) is BI-RADS 4B/4C or 5 regardless of stability.
Guessing at decay, dose, or exposure calculations instead of writing them out, e.g., estimating how much activity remains when a Tc-99m preparation is used hours after elution, or confusing the half-lives of F-18, Tc-99m, and I-131.
Physics and math items feel like trivia under time pressure and are skipped; also, the half-lives are memorized as numbers without units or context.
What to do instead
Write the equation and substitute before looking at options: A = A0 x e^(-0.693t/T1/2), and confirm the units of every term. Drill a small half-life table (Tc-99m 6 h, F-18 110 min, I-123 13 h, I-131 8 d) and apply it to one worked problem per isotope.
Classifying renal cysts by overall appearance instead of by measured enhancement and wall/septal characteristics, e.g., labeling a hyperdense cyst as a solid mass, or calling a cyst with hairline septa Bosniak III and sending it to surgery.
Enhancement is a number, but candidates judge it by eye; hyperdense nonenhancing cysts and small solid components are the classic look-alikes.
What to do instead
Measure attenuation on unenhanced and post-contrast phases at the same ROI; regard an increase of approximately 15-20 HU (or >20% relative) as true enhancement. Then apply the Bosniak categories strictly: thin smooth wall/hairline septa = II, minimally thickened or many septa = IIF, thickened irregular enhancing wall or measurable enhancement = III/IV, nodular solid component = IV.
Describing a bone or soft-tissue lesion without anchoring the differential to the patient's age and the lesion's location and zone of transition, e.g., treating a well-marginated metaphyseal lucency with a sclerotic rim in a child as an aggressive lesion requiring biopsy.
The descriptive report is generated from image features alone, and the pediatric 'leave-me-alone' lesions are mistaken for tumor because the age bracket is treated as incidental rather than diagnostic.
What to do instead
Force an explicit framework before committing: age bracket, skeletal location (epiphysis/metaphysis/diaphysis, central vs eccentric), margin and zone of transition, matrix, and periosteal reaction. A narrow zone of transition with a sclerotic rim in a skeletally immature patient points to fibrous cortical defect/nonossifying fibroma, not malignancy.
Naming a vascular territory or syndrome from the clinical syndrome alone, e.g., attributing a homonymous hemianopia or an isolated third-nerve palsy to an MCA-territory infarct, or labeling a brainstem picture as cortical.
Time pressure favors naming the most familiar diagnosis; the localization step is treated as a formality and skipped.
What to do instead
Localize first, in writing: which tract, cranial nerve, or vascular territory explains every sign, and does one lesion account for all of them? Only after the localization is internally consistent should you pick the etiology. Cross-check the territory against the supplied vascular distribution (e.g., hemianopia = contralateral occipital/PCA, not MCA).
Reflexively correcting mild laboratory abnormalities before a low-risk image-guided procedure, e.g., ordering fresh frozen plasma for an INR of 1.5 or deferring a core biopsy for a platelet count of 60,000.
Old thresholds and institutional folklore persist, and the candidate replaces guideline-based risk stratification with a memorized number from a single prior rotation.
What to do instead
Apply current society (SIR) periprocedural consensus thresholds stratified by bleeding risk: for most percutaneous image-guided procedures, INR up to about 2.0 and platelets of roughly 50,000/microliter are acceptable, with lower thresholds for low-risk superficial procedures. Know which procedures are high risk (renal, biliary, vascular) and which anticoagulants need bridging versus holding.
Importing adult assumptions into a pediatric case, e.g., reporting a normal thymus as an anterior mediastinal mass, using adult CT technique/dose parameters, or discharging an infant with a femur fracture without a skeletal survey.
Most training volume is adult, and pediatric normal variants plus nonaccidental trauma patterns are learned late and thinly; the adult template is applied by default.
What to do instead
Keep a short pediatric-specific checklist: normal thymus appearance by age, age-appropriate radiation dose and child-sizing, and the child-abuse rule (any fracture in a non-walking infant, or a femur/torso injury in a young child, warrants a skeletal survey and documented reporting).
Treating an artifact as pathology or vice versa, e.g., diagnosing a gallstone from a hyperechoic focus showing twinkling artifact without posterior shadowing, or calling a cyst purely on the basis of posterior acoustic enhancement.
Artifacts and true findings share the same visual vocabulary, and artifact physics is memorized as a list of names rather than as a set of manipulable predictions.
What to do instead
For any echogenic or cystic-appearing structure, apply confirmatory criteria instead of one sign: a gallstone requires a mobile, shadowing echogenic focus within the lumen; twinkling alone indicates a calcific/rough surface and can occur in non-biliary locations. Change the patient position, angulation, or focal zone and see whether the 'finding' behaves as predicted.