- in radiography of the lung, a crescent of gas near the top of a mass lesion, signifying cavitation with a space above the debris; seen in aspergilloma, hydatidoma;
- in computed tomography, a high attenuating layer of new blood in an aneurysm; indicates a ruptured abdominal aortic aneurysm;
- in diagnostic ultrasound, a sonolucent crescentic layer in a tumor mass, typically necrosis in stromal tumors of the small bowel;
- in diagnostic ultrasound, a hyperechoic crescent, representing the entering limb of an intussusception; also known as crescent-in-a-doughnut;
- in osteoradiology, a subcortical lucent crescent in the femoral head, signifying osteonecrosis.
Synonym(s): meniscus sign
Search Stedman's Medical Dictionary
Examples: glitazone, GI cocktail, etc.