Objective: CEA and CAS are done to treat carotid artery stenosis, but clear eligibility criteria have not been established. In this study we evaluated arterial plaque objectively by IBS analysis with an ultrasound machine with an AD function, and classified the types of arteriosclerotic lesions according to the AHA criteria. Methods: The ultrasoud machine employed was a sonos 5500 with a L7540 probe; system setting gain 50% compression 70% TGC 159 LGC 0). We compared the histopathology in a total of 121 locations using the IBS value in 40 patients (31 men, 7 women) who underwent CEA between May 2002 and September 2003, and calculated the IBS value for hemorrhage, lipid, fibrosis, and calcification. The AHA type distinction classified 24 cases (22 men, 2 women) between November 2003 and June 2004, and its utility was reviewed. Results: We recognized a significant difference between hemorrhage and lipid (P<0.05), lipid and fibrosis (P<0.0001), and fibrosis and calcification (P<0.0001). Each IBS calculated a value with 80% sensitivity: hemorrhage<39 dB, 39 dB≤lipid>45 dB, 45 dB≤ fibrosis<50 dB, 50 dB≤calcification. We carried out ultrasonic diagnosis of 24 case using these values and this yielded 10 cases of AHA Type VI, 4 cases of AHA Type Va, 3 cases of AHA Type Vc, and 4 cases of AHA type Vb. In 3 cases measurement was not possible because of an acoustic shadow due to calcification. Tissue diagnosis yielded 8 cases of AHA Type VI, 7 cases of AHA Type Va, 2 cases of AHA Type Vc, and 4 cases of AHA type Vb. The concordance rate became 86%. The results suggested that this examination is useful for CEA, and choice of stenting.
