Welcome to Case 2 in our Radiology Into Action series – designed to help medical students and resident doctors approach common acute presentations encountered whilst on-call, with a focus on practical radiology interpretation and clinical decision-making. New cases are released regularly, so check back as the series continues to grow.

If you missed Case 1, you can find it here.

Radiology Into Action: Case 2

Imagine yourself as an F1 doctor covering the medical wards overnight in a busy tertiary hospital.

You are bleeped by the nursing team to review a chest x-ray for a middle-aged man who presents with worsening breathlessness (worse when lying flat) and leg swelling.

What do you do?

Step 1: Interpret

In this PA chest x-ray we can see:

• Blunting of costophrenic angles bilaterally indicating bilateral pleural effusions. Classically, in heart failure there is more fluid accumulation in the right lung base.
• Cardiothoracic ratio > 0.5 indicating cardiomegaly
• Prominent upper lobe vessels due to pulmonary venous hypertension secondary to raised left atrial pressure

Other expected signs in congestive heart failure include: alveolar oedema (presenting as ‘bat-wing opacities’ in the perihilar region) and kerley B lines (peripheral horizontal lines due to thickened interlobular septa).

Remember the mnemonic ABCDE for acute heart failure:

A – Alveolar oedema (bat-wing opacity)

B  – Kerley B lines

C – Cardiomegaly

D – Dilated upper lobe vessels

E – Effusions (often bilateral)

Quick Recap: Pleural Effusions

A pleural effusion describes the abnormal accumulation of fluid in the pleural space (between the visceral and parietal pleura).

Types and Causes:

• Transudative – protein < 30g/L
  • Systemic cause leading to raised hydrostatic pressure or reduced oncotic pressure
  • Congestive cardiac failure (most common)
  • Liver cirrhosis
  • Hypoalbuminaemia
  • Nephrotic syndrome
  • Mitral stenosis
  • Peritoneal dialysis
  • Chronic hypothyroidism
  • Constrictive pericarditis

• Exudative – protein > 30g/L
  • Local pathology causing increased pleural capillary permeability, impaired lymphatic drainage or direct pleural invasion
  • Malignancy: mesothelioma, metastatic breast/lung cancer, lymphoma
  • Pleural infection or pneumonia (aka parapneumonic effusion)
  • Pulmonary embolism
  • Autoimmune pleuritis: rheumatoid arthritis, SLE
  • Drugs: amiodarone, cyclophosphamide, nitrofurantoin, methotrexate, phenytoin
  • Lymphatic disorders
  • Meig’s syndrome (triad of: benign ovarian tumour, ascites and right-sided pleural effusion)
  • Post-coronary artery bypass graft
  • Benign asbestos-related effusion

• If bilateral:
  • Congestive cardiac failure
  • Hypoalbuminaemia
  • Renal/liver failure
  • Systemic lupus erythematosus
  • Widespread malignancy (abdominal/pelvic)
  • Bilateral pulmonary embolism

Pleural Fluid Interpretation

Ultrasound-guided diagnostic pleural fluid aspiration samples are sent for:

• Biochemistry (glucose, LDH, pH, protein)
• Microbiology (culture and sensitivity)
• Cytology

Protein level

• Exudate: >30g/L
• Transudate: <30g/L
• Grey zone: 25–35g/L → apply Light’s criteria

Fluid appearance

• Clear straw-coloured: transudate
• Blood-stained: mesothelioma, pulmonary embolism, tuberculosis, trauma
• Purulent: empyema (infection)
• Milky: chylothorax (lymphatic leak) or pseudochylothorax (in rheumatoid arthritis/tuberculosis)
• Black: malignant melanoma or Aspergillus niger (rare)
• Brown: amoebic liver abscess (rare)

Other features

• Low glucose: rheumatoid arthritis, tuberculosis
• Raised amylase: pancreatitis, oesophageal perforation
• Low complement (C3/C4): systemic lupus erythematosus
• High triglycerides: chylothorax

Now that we know that this patient has congestive cardiac failure, what do we do next?

Step 2: Assess

The nursing team provides you with the following observations:

RR 22, sats 87% on air, HR 113, BP 105/89, temp 37.2

• Immediately escalate to the senior medic on-call.
• Stabilise observations:
  • Hypoxia: Give high-flow oxygen (15L/min) via a non-rebreather mask to maintain saturations of 94-98%.
• Assess the patient using an A-E approach:
  • Inspection: tachypnoea, tachycardia, peripheral cyanosis, raised JVP, ankle oedema
  • Palpation: displaced apex beat
  • Percussion: stony dullness over lung bases
  • Auscultation: bi-basal crackles, S3 heart sounds (may be subtle)

Step 3: Manage (senior-led)

Heart failure management:

• Loop diuretics – IV furosemide 40 – 80 mg
• Manage fluid input – fluid restriction
• Nitrates
• Oxygen
• Position – sit patient upright

Further management options

Therapeutic aspiration

• USS-guided aspiration via the lateral chest wall is used for symptomatic, large pleural effusions
• To avoid re-expansion pulmonary oedema, where a large volume of pleural fluid around a collapsed lung is drained too quickly, drain a maximum of 1.5L per session
• Signs of re-expansion pulmonary oedema:
  • Chest pain
  • Cough +/- haemoptysis
  • Hypoxia
• Treatment is mainly supportive with oxygen supplementation for mild presentations. In severe cases, mechanical ventilation may be required.

Chest drain (tube thoracostomy)

• Consider intercostal drain insertion (8-14Fr small bore) if:
  • Pleural fluid frankly purulent or turbid
  • Pleural fluid pH <7.20
  • Pleural fluid pH 7.21 – 7.39 and LDH ≥ 900
    • Especially if large volume, low glucose, pleural contrast enhancement on CT or septation on USS

• Intercostal drain basics
  • Inserted in the triangle of safety – bordered by: lateral edge of pectoralis major, lateral edge of latissimus dorsi and 5^th intercostal space
  • Monitor for swinging (indicating patency) and bubbling (indicating unwanted air leak)
  • Consider removal when: swinging stopped and daily CXR shows adequate lung re-expansion
  • Refer for video-assisted thoracoscopic surgery (VATS) if persistent effusion despite chest drain insertion

Management of recurrence

Consider:

• Recurrent aspiration for short-term relief
• Pleurodesis – chemical (talc) or surgical
  • Seals pleural space to prevent further fluid build-up
  • Via medical thoracoscopy or chest drain
• Long-term indwelling pleural catheter (IPC): preferred for malignant pleural effusion
• Video-assisted thoracic surgery (VATS): allows direct visualisation in complex cases
• Opioids for breathlessness relief – particularly in a palliative context

Article written by Dr Talha Raza (FY1)
Reviewed by Dr Olivia Parish (MTB Radiology Lead)

References

1. https://www.radiologymasterclass.co.uk/gallery/chest/cardiac_disease/pleural_effusion#top_1st_img
2. https://thorax.bmj.com/content/78/11/1143
3. https://radiopaedia.org/articles/congestive-cardiac-failure?lang=us
4. https://www.rcemlearning.co.uk/reference/pleural-effusion/#1571046545819-65806fc0-b2d9
5. https://www.cmaj.ca/content/182/18/2000