| Paraplegina to ischemic complication of the spinal cord after the treatment of the traditionary surgery or the endovascular surgery is a serious event. The primary reason is that the bloody-supply of the artery of Adamkiewicz(AKA) is demolished. However, it is difficult to overview the location of the AKA at the preoperative traditionary angiography, which may lead to the risk of postoperative paraplegia after the hypodesis, damage, or coverage with the stent-graft of the AKA during the operation. Therefore, it is the important topic to the fixing AKA properatively.With the deveploment of the imageology, CT angiography(CTA) plays an more and more important role in evaluation of vascular diseases. Particularly recent years, the multi-detector-row CT angiography(MDCTA), a recently developed imaging teachnique, enable the examinations covered an extensive range in the craniocaudal direction with thin collimation in a short time interal. As a result, AKA could be visualized preoperatively.Objectives1 .To Assess the ability of MDCTA(16-slice spiral CT) to depict AKA.2.To use MDCTA which may scan one time to depict the information on aortic aneurysm ICA/LA, AKA and ASA, and to investigate the visualization of the artery of Adamkiewicz with the optimized scanning parameters, scan delay time and reconstruction methods.3.In the order to provide morphology data to surgery and imagelogy,CT image of AKA was observed.4. To assess the visualization of the AKA by using MDCTA in patients with thoracoabdominal aortic aneurysms, for giving aids in surgical planning and reducing the incidence of intraoperative ischemic injury of the spinal cord and to prevent postoperative paraplegia.Materials and Methods1. Retrospective study: Between July 2005 and May 2006, a total of 98 patients (males and females) underwent contrast-enhanced MDCT angiography in Radiology Department of 301 Hospital,BeiJing. According to different scan delay time, they were separated into three groups; in the first group, 34 cases enroll as delay time 23 second;in the second group,31 cases enroll as delay time 40 second; in the third group,33 cases enroll as delay time 60 second. Then, the display rate of the AKA in each group was compared in order to show the different scan delay time. The purpose of our study was to investigate the optimization of MDCTA techniques, in terms of scan-triggering CT threshold, scan delay time and image post-processing methodology, for the depiction of the detailed anatomy of the artery of Adamkiewicz.2.prospective study: Using two series scan techniques by MDCT, we scanned 23 consecutive patients with thoracoabdominal aortic aneurysms in same period of time. According to different scan delay time, they were divided into two groups(according to delay time 23 seconds and 45.5 seconds, they were divided into the fourth group and the fifth group, respectively.) and scaned by MDCT with two series. Then ,the display rate of the AKA in each group was compared in order to show the different scan delay time.3. All MDCTA data were processed by various reconstruction techniques including volume rendering technique (VRT), multiplanar reformation (MPR), curved planar reformation (CPR) and maximum intensity projection (MIP) to delineate the artery of Adamkiewicz and other related arterial minute dissection.Results1. The best scanning parameters were showed as following: 0.5 seconds per rotation, 1mm slice thickness, 1.375 pitch; 100± 10ml of a contrast material containing 320 mg of iodine per milliter, a rate of 3.5ml/second. The display rate of 1 group, 2 group, and 3 group was 24%,68%,and 27%. There were significant deviation among the groups (a=0.05).2, Patients with suspected disease of the aorta had been scanned,the dispaly ratio of the fourth group and the fifth group is 17% and 61%, respectively. There is significant devation between them (a=0.05); however, there is no significant devation between the first group and the fourth group, the second group and the fifth group,respectively.3. Using the optimized MDCTA techniques, the anterior spinal artery was clearly visualized in CT imaging. The anatomic continuity of the entire course of the artery of Adamkiewicz, which presented the characteristic hairpin-like junction with the anterior spinal artery, was clearly depicted in 62 of 80(77%) subjects who had a single artery of Adamkiewicz. Two arteries of Adamkiewicz were identified in 18of the 80 subjects (23%). There were seventy-one arteries of Adamkiewicz (71/98, 72%) originated from the left side and eighty-six (86/98, 88%) originated between the level from T8 to T12. The diameter of ascending branch is 0.5±0.2mm and the descending branch is 1.0±0.2mm .ConclusionsUsing the optimized scan delay time (40s) , 16-slice MDCTA can clearly depict the detailed anatomy of the artery of Adamkiewicz (including the origin, the branching patterns and the entire course). As an optimized imaging technique, two series scan by MDCTA should therefore be the preoperatively method of choice for the depiction of the artery of Adamkiewicz.The developing of descending limb is easier than the ascending limb. |
