Case 21 Answer

Not too hard right?

Enlarged, hypervascular thyroid gland = thyroiditis. In this case, and perhaps[s most commonly, Graves disease would be culprit. 

reference: https://radiopaedia.org/articles/thyroid-inflammatory-conditions

This usually is not imaged since the physical exam and symptoms are usually fairly textbook, but on occassion you might get a triage order for “neck mass” which is really just a swollen tender thyroid gland.  Remember, this can also be a cause of dysphagia.