| Objectives: 1. Using Multi-Detector-Row spiral CT angiography (MDCTA) (16-slice spiral CT) to investigate the visualization of the artery of Adamkiewicz with the optimized scanning parameters, scan delay time and reconstruction methods. 2. To assess the visualization of the artery of Adamkiewicz using MDCTA in patients with thoracoabdominal aortic aneurysms, so as to aid in surgical planning and help to reduce the incidence of intraoperative ischemic injury of the spinal cord and to prevent postoperative paraplegia.Materials and Methods: 1. Between Sept 2003 and May 2004, a total of 125 consecutive subjects (96 males and 29 females) without any history of thoracic and abdominal lesions underwent contrast-enhanced MDCT angiography in Radiology Department of West China Hospital, Sichuan University, thus they were enrolled as the "Normal Group" of the study to prospectively 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. Using the optimized MDCTA techniques, we prospectively scanned 23 consecutive patients with thoracoabdominal aortic aneurysms (aneurysmal dilatation of thoracic aorta in 7 and abdominal aorta in 10, 3 thoracoabdominal aortic dissecting aneurysms, and 3 aortic dissection) in same period of time. 3. All MDCTA data were processed by various two-dimensional and three-dimensional reconstruction techniques including maximum intensity projection (MIP), multiplanar reformation (MPR), curved planar reformation (CPR) and volume rendering technique (VRT) to delineate the artery of Adamkiewicz and other related arterial structures.Results: 1. The best scanning parameters using 16-slice MDCTA to visualize the artery of Adamkiewicz were as follows: 0.5 seconds per rotation, 0.75mm slice thickness, 1.5 pitch; Measured with ROI placed in the descending thoracic aorta at T7 level, CT value of 170Hu was selected as the threshold to trigger data acquisition; When this CT threshold value was reached, we delayed the scanning for another 18 seconds, then helical scanning automatically began. Axial images were reconstructed with B 20f algorithm, 1mm slice thickness and 0.75mm interval. VRT, MPR, MIP and CPR were used for image post-processing. 2. Using the optimized MDCTA techniques, the anterior spinal artery was clearly visualized in all normal subjects and patients with aortic aneurysm. The artery of Adamkiewicz was visualized in 41of 45 normal subjects (91.1%) and in 21of 23 aneurysmal patients (91.3%). The anatomic continuity of the entire course of the artery of Adamkiewicz, starting from the aorta to the intercostals artery and ending at the characteristic hairpin-like junction with the anterior spinal artery, was clearly depicted in 27 of 45 normal subjects (60%) and in 14 of 23 patients (60.9%). There were 31 in the 41 normal subjects (75.6%) who have a single artery of Adamkiewicz. Two arteries of Adamkiewicz were identified in 10 of the 41 normal subjects (24.4%). Altogether a total of 51 arteries of Adamkiewicz were visualized. There were thirty-nine arteries of Adamkiewicz (39/51, 76.5%) originated from the left side and forty-nine (49/51, 96.0%) originated between the level from T7 to T12.Conclusions: Using the optimized scanning and reconstruction techniques, 16-slice MDCTA can clearly depict the detailed anatomy of the artery of Adamkiewicz (including the origin, the branching patterns and the entire course) both in normal subjects and in patients with thoracoabdominal aortic aneurysms. As a noninvasive and efficient imaging technique, optimized MDCTA should therefore be the method of choice for the depiction of the artery of Adamkiewicz.
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