Iraqi Board Radiology common mistakes
Iraqi Board Radiology · Understand the traps and how to avoid them.
Calculating CT dose indices from memory without tracking the distinction between CTDIvol (per-slice, phantom-based) and DLP (CTDIvol × scan length), then reporting a whole-body effective dose that ignores the region-specific tissue weighting factors.
Candidates memorise a single 'CT dose' number and apply it to every protocol; the exam deliberately varies collimation, pitch and scanned length, and pitch >1 reduces CTDIvol-referenced dose but not CTDIvol itself, so candidates who do not separate the terms produce internally inconsistent answers.
What to do instead
Build a one-page formula sheet: CTDIw = (1/3)CTDIcenter + (2/3)CTDIperiphery; CTDIvol = CTDIw/pitch; DLP = CTDIvol × scan length (cm); effective dose = DLP × k-factor for the body region. Practise three worked examples (head, chest, abdomen) and state units (mGy, mGy·cm, mSv) explicitly in every answer.
Answering radiation-protection questions by applying ALARA as a slogan instead of choosing the concrete action: e.g. selecting a grid or collimation change when the question asks for the single most effective way to reduce occupational dose in fluoroscopy.
The physics/protection syllabus rewards quantitative reasoning (inverse-square, half-value layer, dose-rate versus time), but candidates revise from summaries that list principles without worked trade-offs, so they cannot rank interventions by magnitude of effect.
What to do instead
For each protection scenario, rank by magnitude: distance (inverse square) > shielding (HVL/TVL calculation) > time > collimation/beam-on time. Practise calculating dose at 2 m versus 1 m, and the number of HVLs needed for a specified attenuation, before attempting MCQ options.
Describing a chest radiograph or CT pattern by naming a diagnosis first ('this is sarcoidosis') and then listing features, rather than systematically describing distribution, laterality, chronicity and associated findings before offering a differential.
Clinical years train pattern recognition and candidates transfer that habit to a structured-answer exam where marks are allocated to semiology; the descriptive vocabulary (upper-zone versus lower-zone, perilymphatic versus centrilobular, honeycombing versus traction bronchiectasis) is under-rehearsed.
What to do instead
Use a fixed reporting template for every chest case: technical adequacy, distribution (zonal, central/peripheral), pattern (reticular, nodular, ground-glass, consolidation, cavitation), associated findings (volume loss, lymphadenopathy, effusion, calcification), then a ranked differential with the single best next test. Rehearse the template aloud on 20 random cases.
Confusing the HRCT features that separate usual interstitial pneumonia from fibrotic hypersensitivity pneumonitis and NSIP, particularly the significance of honeycombing, traction bronchiectasis, air trapping and the presence or absence of upper-zone predominance.
The three patterns share fibrosis and are taught together; candidates memorise 'UIP = honeycombing' without learning that honeycombing must be subpleural and basal-dominant, and that air trapping on expiratory imaging favours hypersensitivity pneumonitis.
What to do instead
Make a three-column comparison table (UIP / fibrotic HP / NSIP) with rows for distribution, honeycombing, ground-glass, air trapping, mosaic attenuation and mediastinal nodes. Test yourself by covering one column and reconstructing it from memory.
Reading an abdominal CT or ultrasound question without localising the lesion to a specific organ and segment, then offering a generic differential ('liver lesion - could be haemangioma, adenoma, HCC, metastasis') instead of using enhancement pattern, phase and patient risk factors to discriminate.
Multiphase CT timing (arterial, portal venous, delayed) is conceptually difficult and candidates often cannot recall which phase shows which feature, so they default to listing all possibilities rather than committing to the pattern that the question is testing.
What to do instead
Learn a phase-by-phase grid for the common liver lesions: haemangioma (peripheral nodular, centripetal fill-in), FNH (arterial hyperenhancement, central scar, isointense on portal venous), adenoma (arterial enhancement, no portal-venous washout in most subtypes), HCC (arterial hyperenhancement with portal-venous or delayed washout, capsule). Practise stating lesion density on unenhanced, arterial, portal venous and delayed phases for each.
Interpreting renal and adrenal imaging by size alone, e.g. calling every adrenal mass larger than 4 cm malignant or every renal cyst simple without applying Bosniak criteria (septa, calcification, enhancement, wall thickness).
Candidates conflate the urology surgical thresholds with radiological classification systems and have not practised applying Bosniak or the adrenal washout calculation, so they cannot distinguish a Bosniak IIF cyst from a Bosniak III cyst or an adenoma from a metastasis on delayed imaging.
What to do instead
Work through the Bosniak categories I to IV with a written descriptor for each, and compute adrenal absolute and relative washout (absolute >60%, relative >40% suggests adenoma) on at least five practice cases. State the criterion you used in every answer.
Missing the 'do not touch' or 'do not miss' finding in a musculoskeletal radiograph - posterior shoulder dislocation, scaphoid fracture, posterior malleolar fracture, or a subtle cortical buckle in a child - because the candidate jumps to the obvious abnormality and stops searching.
Search patterns are learned on busy clinical lists where the obvious finding ends the review; in an exam each radiograph is chosen to contain a second, decision-changing finding, and candidates have not rehearsed a systematic review of every bone and joint line.
What to do instead
Adopt an anatomical checklist for each region (shoulder: glenohumeral overlap, lightbulb sign, trough line; wrist: scaphoid, triquetrum, distal radius; ankle: posterior malleolus, talar dome, base of fifth metatarsal) and force yourself to run it on every film before writing the answer.
Answering brain and spine questions by naming the most likely diagnosis without localising the lesion or describing the signal characteristics on the specific sequences (DWI/ADC, FLAIR, T1 pre/post, GRE/SWI) that the question is built around.
Neuroanatomy and MRI sequence physics are examined together, and candidates who are weak on one compensate by pattern-matching the clinical vignette; the result is a correct-sounding diagnosis with an unsupported justification, which loses marks in structured answers.
What to do instead
For every neuro case, write the localisation first (lobe, grey versus white matter, infratentorial versus supratentorial, intra- versus extra-axial), then the signal on each sequence, then the differential. Drill restricted diffusion (DWI bright, ADC dark) versus T2 shine-through until it is automatic.
Treating breast imaging as a single modality, e.g. answering a screening question with ultrasound or MRI, or misapplying BI-RADS categories by assigning a final assessment without integrating mammographic density, lesion margins and stability over time.
Candidates revise BI-RADS as a list of numbers but do not practise the decision pathway from finding to category, and they confuse the roles of screening mammography, diagnostic work-up and adjunctive ultrasound or MRI in dense breasts.
What to do instead
Write the BI-RADS decision tree: category 0 needs additional imaging; 2 is benign; 3 is probably benign with short-interval follow-up; 4 is suspicious (subdivide 4A/4B/4C); 5 is highly suggestive of malignancy; 6 is known biopsy-proven. Apply it to ten vignettes and justify the category with the specific descriptor (margin, shape, density, calcification morphology).
In paediatric and emergency radiology, applying adult algorithms to children - using adult CT parameters, adult fracture classifications or adult contrast doses - and failing to choose the modality that avoids ionising radiation when an alternative exists.
Paediatric protocols and age-specific normal variants (e.g. physiologic periosteal reaction, accessory ossification centres, normal thymus) are taught briefly and candidates default to adult frameworks; the exam includes several questions where the correct answer is 'do ultrasound first' or 'use a lower-dose protocol'.
What to do instead
Memorise age-based CT kVp/mAs ranges, the 'as low as reasonably achievable' paediatric principles, and a short list of paediatric normal variants that mimic disease. For each emergency vignette, ask explicitly whether ultrasound or MRI could answer the question before selecting CT.