Carcinoid enhancement:
The lesion in the right lower lung in this case had been slowly enlarging over a period of 4 years. The patient was reluctant to undergo surgery, so helical CT was performed following the administration of I.V. contrast to assess for lesion enhancement. The lesion had a non-contrast mean HU of 24, and a maximum post-contrast mean HU of 76. A lesion that enhances greater than 20 HU is highly suspicious for malignancy and should be biopsied or removed. The patient in this case went to surgery and the lesion proved to be a carcinoid tumor.
