CEA test: Carcinoembryonic antigen test is to detect response to therapy in cancer patients, especially colon cancer, with normal range of less than 2.5 (less than 5 in heavy smokers). Note that a positive test may not always be indicative of cancer.
Os Trigonum Syndrome. An Os Trigonum is a small, extra bone found at the back of the ankle in approximately 5-10% of people. Often it goes completely unnoticed, not causing any problems.
1. Os Trigonum on Plain Film 44 years old ballet dancer. 9Accessory ossification found along posterior aspect of talus in 5-15% of population. 9Called trigonal (Stieda's) process when it is fused to the talus. 9Called os trigonum if remains unfused with talus9Inferior surface typically articulates with the calcaneus.