MRCP2-0805

MRCP2-0805

You are in the general medical clinic. A 35-year-old male has been referred by his GP with dyspnoea. His symptoms started about 6 months ago with dyspnea mostly on exertion which is progressively getting worse. He also has a dry cough for last 3 months. There is no orthopnoea or paroxysmal nocturnal dyspnoea. There is also no history of chest pain. His past history includes Hodgkin’s lymphoma which was successfully treated 3 years ago with ABVD regimen. He is currently not taking any medications. He works in a printing press and does not smoke. On examination, there is no raised JVP or ankle oedema. Auscultation revealed normal heart sounds and bilateral fine crackles. Results of his investigations are as follows:

Hb 120 g/l Na+ 140 mmol/l Bilirubin 10 µmol/l
Platelets 190 * 109/l K+ 4.0 mmol/l ALP 90 u/l
WBC 7.0 * 109/l Urea 4.5 mmol/l ALT 20 u/l
Neuts 3.0 * 109/l Creatinine 90 µmol/l γGT 50 u/l
Lymphs 2.5 * 109/l ESR 30 mm/hr Albumin 35 g/l
Eosin 0.2 * 109/l

Chest x-ray normal

What is the next best investigation for evaluation of this patient?