A viva isn't a reporting shift. You don't want to spend ten minutes doing a thorough assessment of the case. You want to stay relevant, and high yield. Avoid rabbit-holes, but not miss the crucial finding.
1. Mediastinal lymph nodes
Assessing mediastinal lymph nodes can be done badly by candidates not used to reading printed films. My tip - find the carina. Look in front of it. Pre-carinal lymph nodes are very common in lung cancer and interstitial lung disease cases. Now look on the two slices below the carina, between the bifurcation. Subcarinal lymph nodes are also really common. Then follow the carina up, paying particular attention to the right paratracheal stations. If you have found nodes here, you can call mediastinal lymphadenopathy.
2. Upper and mid zone nodules
Once you have recognised you are in a nodules case, the differential becomes finite. An exam favourite is sarcoidosis, so if you can classify something as sarcoid early you can get the case down quickly. The key to sarcoidosis often lies in the fissures. Find the oblique fissures on your axial slices, starting superiorly. Look very carefully for beading of the fissures. If you see this, and you can quickly confirm your pattern of nodules - throwing in some elegant descriptors like perilymphatic distribution or a galaxy sign if it's there - and then assess for lymph nodes to clinch it (see above!).
3. Diffuse or confluent parenchymal changes
A conglomerate abnormality can be overwhelming. It can look like nothing or everything at the same time. A was taught, that if the abnormality is large or confusing, look at the periphery as the lesion characteristics will be more sparse. You might see tree-in-bud nodules suggesting endobronchial spread, leading you to ask yourself 'could this be TB?'. You might see nodular septal thickening suggesting lymphangitis, leading you to ask yourself 'could this be cancer?'.
4. Thoracic aortograms
If you are given a non-contrast phase with your aortogram case, look at this first. In real life, the non-contrast is not just for looking for atherosclerosis - it is to assess for intramural haematoma. A common trap is to concentrate on the angiographic phase, doing layers upon layers of assessments when the life-threatening abnormality could have been picked and assessed in 30 seconds. If there is crescentic high density in the aortic wall, call the intramural haematoma. Look for the penetrating ulcer as the cause (it won't always be present) and close the case with the appropriate management - remembering these are emergencies.