Albrecht T, Jäger H R, Blomley M J, Lopez A, Hossain J, Standfield N
Department of Imaging, Hammersmith Hospital, Royal Postgraduate Medical School, London, UK.
Clin Radiol. 1997 Sep;52(9):659-65. doi: 10.1016/s0009-9260(97)80028-1.
The differentiation of supra-, juxta- and high infrarenal abdominal aortic aneurysms (AAA), which is essential for good surgical management, remains problematic. This prospective study assessed the value of highly overlapping vs. contiguous axial spiral computed tomography (CT) reconstructions in the pre-operative assessment of AAA.
Thirty-five patients with abdominal aortic aneurysms were studied with spiral CT (10 mm collimation, pitch 1). Axial reconstructions were performed at 2 and 10 mm increments and compared with surgical findings. Using each protocol, the aneurysms were classified as infra-, juxta- or suprarenal. Observers also assessed visualization of main and accessory renal artery origins and identification of other surgically relevant vascular anomalies.
The 2 mm protocol correctly identified 29/31 infrarenal, 3/3 juxtarenal and 1/1 suprarenal aneurysms; two infrarenal aneurysms were overestimated as suprarenal. The 10 mm protocol correctly classified 25/31 infrarenal, 3/3 juxtarenal and 1/1 suprarenal aneurysms; five infrarenal aneurysms were overestimated as juxtarenal (n = 3) or suprarenal (n = 2) and one case was equivocal. Correct classification was thus 94% using the 2 mm protocol and 83% with the 10 mm protocol (P = 0.063). All 70 main renal artery origins were visualized with the 2 mm protocol, while the 10 mm protocol missed six (P = 0.03) The 2 mm protocol identified 10 accessory renal arteries, four of which were missed by the 10 mm protocol. Both protocols demonstrated five surgically relevant venous anomalies.
Spiral CT with highly overlapping axial reconstructions correctly classified 94% of abdominal aortic aneurysms; overlapping reconstructions were particularly useful in differentiating high infrarenal from juxtarenal aneurysms.
腹主动脉瘤（AAA）的肾上、肾旁及肾下型的鉴别对于良好的手术管理至关重要，但目前仍存在问题。本前瞻性研究评估了高度重叠与连续轴向螺旋计算机断层扫描（CT）重建在AAA术前评估中的价值。
对35例腹主动脉瘤患者进行螺旋CT检查（准直10mm，螺距1）。以2mm和10mm的增量进行轴向重建，并与手术结果进行比较。使用每种方案，将动脉瘤分为肾下型、肾旁型或肾上型。观察者还评估了主肾动脉和副肾动脉起源的可视化情况以及其他与手术相关的血管异常的识别情况。
2mm方案正确识别了29/31例肾下型、3/3例肾旁型和1/1例肾上型动脉瘤；2例肾下型动脉瘤被高估为肾上型。10mm方案正确分类了25/31例肾下型、3/3例肾旁型和1/1例肾上型动脉瘤；5例肾下型动脉瘤被高估为肾旁型（n = 3）或肾上型（n = 2），1例情况不明确。因此，2mm方案的正确分类率为94%，10mm方案为83%（P = 0.063）。2mm方案能显示所有70个主肾动脉起源，而10mm方案遗漏了6个（P = 0.03）。2mm方案识别出10条副肾动脉，其中4条被10mm方案遗漏。两种方案均显示了5个与手术相关的静脉异常。
采用高度重叠轴向重建的螺旋CT能正确分类94%的腹主动脉瘤；重叠重建在区分高位肾下型与肾旁型动脉瘤方面特别有用。
