The idea that assessment is intrinsic to effective instruction is traced from early experiments in the individualization of learning through the work of Benjamin Bloom to reviews of the impact of feedback on learners in classrooms.
Incidental hypervascular lesions are also very common findings in liver imaging. It is important to differentiate between 'touch' and 'don't touch' lesions. Benign 'don't touch' hypervascular tumors include hemangioma, FNH and small adenomas.
For unknown reasons, renovascular hypertension is much less common among blacks than among whites. Overall, about 80% of cases are caused by atherosclerosis and 20% by fibromuscular dysplasia. Atherosclerosis is more common among men 50 and affects mainly the proximal one third of the renal artery.