Correct answer: Pulmonary hypertension. This chest X-ray shows enlarged pulmonary arteries from pulmonary artery hypertension. When caused by interstitial lung disease and leading to right heart failure, this would be termed cor pulmonale. No signs of interstitial lung disease are identifiable in this image. The book (Oxford Handbook of Clinical Medicine, 8th edition) didn’t reveal any further information on e.g. goitre. It may well be true, but I can’t tell that with certainty. CHF seems likely, as well.