The Adamkiewicz artery: demonstration by intra-arterial computed tomographic angiography

The purpose of this study was to evaluate the feasibility of using multidetector-row CT angiography (CTA) with intra-arterial contrast injection (IA-CTA) to depict the artery of Adamkiewicz (arteria radicularis magna, ARM).

We performed IA-CTA in 27 preoperative patients with aneurysm or dissection of the descending thoracic or thoracoabdominal aorta. ARM was examined on multiplanar and curved planar reformation images and on the paging method, and we investigated detectability and visualization of the ARM, the level of branching, and right/left frequency as well as continuity from the origin to the ARM. Furthermore, the bolus characteristic of contrast medium in IA-CTA was investigated and compared with CTA with intravenous contrast injection (IV-CTA). The bolus characteristic of the contrast medium was assessed by the determination of the CT value in the aorta in each of the 16 cases in which both IA-CTA before surgery and intravenous IV-CTA at the time of admission were performed.

The ARMs were clearly visualized and at least one ARM to be reserved was determined in all patients (100%). The average number of ARM observed was 1.4+/-0.58 per patient (39/27). Innate origin was determined in 90% (35/39) of ARMs and it ranged between the 8th thoracic vertebra and the 3rd lumbar vertebra levels, and branching from the left accounted for 63.2% (24/38). It was possible to observe the exact continuity from the innate origin to the ARM as well as from the secondary origin to the ARM mediated by collateral vesseles in 61.5% of the total ARMs (24/39). The CT value in the aorta calculated on IA-CTA was significantly higher than that on IV-CTA (p<0.05). As a result, the high bolus characteristic of contrast medium in IA-CTA was confirmed.

It was possible to detect the ARM in all patients and to obtain information about the origin by IA-CTA. This method is considered useful for preoperative assessment of a descending thoracic or a thoracoabdominal aorta for aortic aneurysm or dissection.