You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which one of the following is not a CT feature of Adrenal adenoma? and explain in detail?
Enhances rapidly, contrast stays in it for relatively longer time and washes out late Adrenal adenomas show rapid contrast enhancement and rapid subsequent washout; whereas nonadenomas (adrenal ca, mets and pheochromocytomas) show slower washout. Characterstics of adenomas (which help differentiate it from nonadenomas) Homogenous well defined rounded tumor; usually smaller than 4 cm Low attenuation on CT Signal loss on MR chemical shift imaging Contrast enhancement pattern (adenomas show rapid enhancement and rapid washout whereas nonadenomas show delayed washout) Findings s/o malignancy in an incidentally discovered adrenal mass (Harrison 17/e p2258) - large size >4 cm - tumor inhomogenesity and irregular margins - calcifications - high attenuation of CT - no loss of signal on Chemical shift MR