Subtraction technique of 64-slice spiral CT angiography for intra- and extra-cranial artery imaging / 第二军医大学学报

ABSTRACT

Objective: To employ the subtraction technique of 64-slice spiral CT angiography for intra- and extra-cranial arteries imaging, so as to study the managing method and assess the clinical outcome. Methods: The pre-contrast and post-contrast images of 100 patients were obtained by 64-slice spiral CT angiography. A special head holder was used during the scanning to guarantee the accurate overlapping of the pre-contrast and post-contrast images. A reconstructed three-dimensional model of the pre-contrast bone dataset was subtracted from the post-contrast dataset to produce the subtracted images. (1) An experienced operator performed the conventional and subtraction reconstructions; the periods for image generation of both methods were recorded and compared. (2) The quality of the images were evaluated and graded (grade 1-5) by 2 experienced radiologists in a double-blinded manner. Results: (1) The new subtraction technique using 64-slice spiral CT angiography needed significantly less time than the conventional method did (11.01±1.89 min vs 14.30±2.25 min, P<0.01). (2)The correlation coefficient of the results of 2 radiologists was 0.87. The score of image quality by subtraction 64-slice spiral CT angiography was significantly higher than that by the conventional method (4.22±050 vs 2.93±0.36, P<0.05). Conclusion: Subtraction 64-slice spiral CT angiography is easy to use and time saving for intra- and extra-cranial artery imaging; it does not has the difficulty of separating artery from bone and is worth popularizing in clinic.