[Clinical applications of routine subtraction and dual-energy subtraction cervical arteries computed tomographic angiography for cervical arteries imaging].

OBJECTIVE: To compare with the clinical applications of routine-subtraction and dual-energy subtraction cervical arteries computed tomographic angiography (CTA) for cervical arteries imaging. METHODS: Scanning was performed in 45 patients with clinically suspected cervical arteries disease with dual-source CT. The data of two different energy were collected only at one scanning. The data post processing include: conventional bone-removal digital subtraction (routine-subtraction) was performed with plain and 80 kV enhanced scanning. Volume render (VR) and maximum intensity projection (MIp) reconstruction were finished. Direct bone-removal digital subtraction (dual-energy subtraction) was performed with 80 and 140kV enhanced scanning that have different energy, and saving the data of subtraction. VR and MIp reconstruction were finished. The image quality, which was divided into four grades, was compared between these two groups. The effective radiation dose was also compared. RESULTS: For normal vessels, no abnormality was found in 24 of 45 cases, with the common carotid artery and its branches clearly displayed with both two methods. The image quality was not significantly different between dual-energy subtraction CTA and routine subtraction CTA (P>0.05) . For stenotic vessels, 45 stenotic vessels in 21 cases were clearly displayed clearly with both two methods (P>0.05) . The effective radiation dose was decreased by 17.3 % for dual-energy subtraction CTA when compared with routine-subtraction CTA (P<0.01) . CONCLUSIONS: Both routine-subtraction and dual-energy subtraction CTA can clearly display normal and stenotic vessels. The radiation exposure dose is relatively lower in dual-energy CTA. The dual-energy subtraction CTA has better effectiveness when used for non-cooperation patients.