Left upper quadrant collection
This case is a good one to test the fellowship candidate, starting with the plain film.
The candidate should make a sensible description and differential for the appearances before 'earning' the right to suggest a further investigation ( CT or ultrasound ) to review further.
The CT is then presented with the opportunity for the candidate to report the findings of the CT and try to give a definitive diagnosis and potentially management plan.
In this case the candidate might highlight the amenability of the collection to ultrasound guided percutaneous drainage.
** of interest the splenic flexure is above the mass, which nearly excludes the commonest left upper quadrant mass, that of splenomegaly.