Objective To evaluate the visualization of the anterior spinal artery (ASA) and the artery of Adamkiewicz (AKA) as well as the affecting factors for the detection rate using multidetector row CT (MDCT). Methods Ninety-nine consecutive patients (31 women and 68 men; age range, 25-90 years; average age 61.3 years) with suspicion for thoracic aortic lesions necessitating surgical intervention (31 aortic aneurysm, 45 dissection, 5 intramural hematoma, and 18 normal), underwent 16-slice MDCT angiography from the aortic arch to the aortic bifurcation. Transverse sections, multiplanar reformations (MPR) and thin maximum intensity projections (MIP) were used to assess the ASA and AKA. The level of the ASA and AKA origins and CT acquisition parameters were recorded. The contrast-to-noise ratio (CNR) of the image, an index of the mass of the T11 body (vertebral mass index), the subcutaneous fat thickness,and the CT value within the aortic arch and at the T11 level were measured. The detection of the ASA and AKA was evaluated relative to the acquisition parameters, scan characteristics, and aortic lesion type. Differences were assessed with Wilcoxon rank-sum and t tests. Results The ASA was visualized in 51 patients (52%) and the AKA in 18 patients (18 %). The ASA was identified in 36/67 (54%)patients with 1.25 mm thickness and in15/32 (47%) patients with 2.5-3.0 mm thickness. This difference did not achieve significance (P=0.13). The detection rate of the ASA and the AKA was influenced by vertebral mass index and the CNR (P＜0.05). The amount of subcutaneous fat affected the detection rate of the ASA (P＜0.05) but not the AKA. In CT scans with ASA detection, the mean CT values in the aorta at the arch and at T11 were 360 and 358 HU, respectively; whereas in CT scans without ASA detection, the CT values in the aorta at the arch and at T11 were lower (297 and 317 HU, respectively; both P＜0.05). Conclusion The ASA and AKA were less frequently detected in our cohorts than previous reports. The visualization of the ASA and AKA was significantly affected by aortic enhancement, the vertebral mass index, and the CNR.

BACKGROUNDDamage to the spinal cord after the treatment of the descending thoracic and thoracoabdominal aortic aneurysms is an uncommon but devastating complication. The artery of Adamkiewicz (AKA) is the principal arterial supply of the anterior spinal artery (ASA) in the lower thoracic and lumbar level. The purpose of this study was to evaluate the visualization of the anterior spinal artery and the artery of Adamkiewicz, the affecting factors for the detection rate using multi-detector row CT (MDCT).

METHODSNinety-nine consecutive patients (31 women and 68 men; age range, 25 - 90 years; average age 61.3 years), with suspicion for thoracic aortic lesions necessitating surgical intervention (31 aortic aneurysm, 45 dissection, 5 intramural hematoma, and 18 normal), underwent CT angiography from the aortic arch to the aortic bifurcation. Transverse sections, multiplanar reformations and thin maximum intensity projections were used to assess the ASA and AKA. The level of the ASA and AKA origins and CT acquisition parameters were recorded. The contrast-to-noise ratio of the image, an index of the mass of the T11 body (vertebral mass index), the subcutaneous fat thickness, and the CT value within the aortic arch and at the T11 level were measured. The detection of the ASA and AKA were evaluated relative to the acquisition parameters, scan characteristics, and aortic lesion type. Differences were assessed with the Wilcoxon rank-sum and t tests.

RESULTSThe ASA was visualized in 51 patients (52%) and the AKA in 18 patients (18%). The ASA was identified in 36/67 patients (54%) with 1.25 mm thickness and in 15/32 patients (47%) with 2.5 - 3.0 mm thickness. This difference did not achieve significance (P = 0.13). The detection rate of the ASA and the AKA was influenced by the vertebral mass index and the contrast-to-noise ratio (P < 0.05). The amount of subcutaneous fat affected the detection rate of the ASA (P < 0.05) but not the AKA. In CT scans of ASA detection, the mean CT values in the aorta at the arch and at T11 were 360 and 358 HU, respectively, whereas in CT scans without ASA detection, the CT values in the aorta at the arch and at T11 were lower (P < 0.05), 297 and 317 HU, respectively.

CONCLUSIONSThe ASA and AKA were less frequently detected in our cohort than previous reports. The visualization of the ASA and AKA was significantly affected by aortic enhancement, the "vertebral mass index", and the contrast-to-noise ratio.

Adult ; Aged ; Aged, 80 and over ; Angiography ; methods ; Aortic Aneurysm, Thoracic ; diagnostic imaging ; pathology ; surgery ; Contrast Media ; administration & dosage ; Female ; Humans ; Iohexol ; administration & dosage ; Male ; Middle Aged ; Spinal Cord ; blood supply ; diagnostic imaging ; pathology ; Tomography, X-Ray Computed ; methods