PLAB 2 Radiology: Essential Image Interpretation for OSCE Success

As medical students aspiring to practice in the UK, the PLAB 2 exam stands as a crucial hurdle. While communication skills, history taking, and clinical examination often take centre stage, the ability to interpret and effectively communicate findings from medical imaging is an equally vital skill tested in the OSCEs. Radiology stations might not be explicit, but the interpretation of a Chest X-ray (CXR) or Abdominal X-ray (AXR) can be seamlessly integrated into many scenarios, from an acute presentation in A&E to a ward round discussion.

Mastering radiology for PLAB 2 isn't about becoming a radiologist; it's about confidently applying a systematic approach to common imaging, identifying critical findings, and clearly explaining them to both examiners and simulated patients. Let's decode how to excel in this often-overlooked area.

Why Radiology Matters in PLAB 2

Imagine a scenario where a patient presents with sudden onset breathlessness. You've taken a history and examined them. The next logical step might be a CXR. If an image is presented, your ability to interpret it systematically and integrate it into your management plan will be key. This demonstrates not just your diagnostic acumen but also your ability to link clinical findings with investigations.

A Systematic Approach: Your Best Friend

Confidently approaching an X-ray or CT requires a structured method. For the PLAB 2 exam, focus on common films like CXRs and AXRs, with a basic understanding of CT Head findings.

1. The ABCDE Approach for Chest X-ray (CXR)

This classic mnemonic ensures you don't miss anything crucial:

• A - Airway & Alignment: Is the trachea central? Are there any obvious deviations (e.g., due to pneumothorax, large effusion, or collapse)? Check the alignment of the cervical spine if visible and clinically relevant.

• B - Breathing (Lungs & Pleura): Systematically examine lung fields from apices to bases. Look for:

  • Consolidation: Opacity, often with air bronchograms (e.g., pneumonia).

  • Pneumothorax: Black lucency without lung markings, often with a visible visceral pleural line.

  • Pleural Effusion: Blunting of costophrenic angles, meniscus sign, white opacity.

  • Pulmonary Oedema: Cardiomegaly, upper lobe venous diversion, Kerley B lines, bilateral perihilar bat-wing opacities.

  • Masses/Nodules: Any abnormal densities.

• C - Cardiac & Circulation: Assess heart size (should be <50% of the thoracic diameter on a PA film). Look for widening of the mediastinum (e.g., aortic dissection) or calcifications.

• D - Diaphragm & Disability: Check each hemidiaphragm for contour and position. Look for free air under the diaphragm (indicating perforation). Assess bones for fractures (ribs, clavicles, vertebrae).

• E - Everything Else: Look at soft tissues for subcutaneous emphysema, surgical emphysema, or foreign bodies. Check for tubes, lines, and drains (e.g., endotracheal tube, central venous catheter, chest drain).

2. Abdominal X-ray (AXR) Basics

While less common than CXR, AXRs can appear, often in scenarios of abdominal pain or suspected obstruction/perforation.

• Gas Pattern: Look for dilated bowel loops (small bowel: centrally located, valvulae conniventes; large bowel: peripherally located, haustra).

• Air-Fluid Levels: Multiple air-fluid levels in dilated loops suggest obstruction.

• Free Air: Crescent of air under the diaphragm (perforation).

• Soft Tissues/Calcifications: Look for kidney stones, gallstones, calcified vessels, or organomegaly.

3. CT Head: Key Red Flags

For PLAB 2, you're unlikely to interpret a detailed CT head, but knowing key pathology is useful:

• Haemorrhage: Hyperdense (bright white) areas in acute bleeding (e.g., intraparenchymal, subarachnoid, subdural, epidural).

• Ischaemic Stroke: Hypodense (darker) areas in established infarcts, or early subtle signs like loss of grey-white differentiation.

• Mass Effect: Midline shift, effacement of sulci/ventricles, indicating a space-occupying lesion (tumour, large bleed).

High-Yield PLAB 2 Scenarios

• Acute Breathlessness: Pneumonia, pneumothorax, pleural effusion, pulmonary oedema.

• Trauma: Rib fractures, clavicle fractures, pneumothorax.

• Acute Abdomen: Bowel obstruction, perforation.

Communicating Your Findings in OSCEs

Interpretation is only half the battle; communication is key. Remember:

1. Be Structured: Announce your systematic approach (e.g., "I'll examine this CXR using the ABCDE method").

2. State the View and Quality: "This is an AP/PA erect/supine CXR, which appears adequately penetrated and inspired."

3. Identify the Patient: Confirm patient details (if provided) and date of the film.

4. Describe Abnormalities Clearly: Use simple, non-jargonistic language. "There is a significant white shadowing in the lower right lung field, consistent with pneumonia." Not "There is a lobar consolidation with air bronchograms in the right lower lobe."

5. Correlate Clinically: "This finding correlates well with the patient's fever, cough, and crepitations on examination."

6. Suggest Next Steps: "Based on this, I would initiate empirical antibiotics, monitor oxygen saturation, and consider further blood tests."

7. Address Patient Concerns: If interacting with a simulated patient, explain what the findings mean for them and what the next steps are in a reassuring manner.

Tips for Success

• Practice, Practice, Practice: Look at as many normal and abnormal images as possible. Use online radiology atlases and apps.

• Focus on Common & Urgent: PLAB 2 won't test rare conditions. Concentrate on the high-yield, life-threatening, and common presentations.

• Understand Clinical Context: Always link the imaging to the patient's history and examination findings. Imaging is a tool, not an isolated entity.

• Seek Feedback: If you're practicing with peers, get feedback on your interpretation and communication.

By adopting a systematic approach and focusing on common pathologies, you can confidently navigate radiology stations in PLAB 2, showcasing your comprehensive clinical skills. Good luck!