Comparison of magnetic resonance with computed tomography angiography for preoperative localization of the Adamkiewicz artery in thoracoabdominal aortic aneurysm patients

Preoperative computed tomography angiography (CTA) (a, b) and magnetic resonance angiography (MRA) (c, d, e) in a 63-year-old woman with a Crawford type II thoracoabdominal aortic aneurysm. The curved multiplanar reformation (MPR) of the CTA (a) and first-phase MRA (c) show the collateral segmental supply from the aorta to the Adamkiewicz artery (AKA, arrow) and anterior spinal artery (ASA, arrow). The segmental artery (SA*, arrow) directly connecting to the Adamkiewicz artery is partially occluded. The Adamkiewicz artery is supplied by an intersegmental collateral (COL, arrow), which originates from a SA one vertebral level below. Note that in the coronal MPR of the CTA (b) and first-phase MRA (d), both the Adamkiewicz artery and the great anterior radiculomedullary vein (GARV, arrow) are depicted. There is no separation of the spinal cord artery and vein in this patient in the CTA or first phase MRA. The second-phase MRA (e) shows decreased signal intensity for the Adamkiewicz artery, whereas the GARV becomes slightly thicker and more intense over the two phases. Note that the enhanced vasculature on the midline of the anterior cord surface is the spatially and temporally unresolved combination of the anterior spinal artery and the anterior median vein. The epidural plexus (*) is strongly enhanced in the second-phase image.

Preoperative computed tomography angiography (CTA) (a) and magnetic resonance angiography (MRA) (b) of the Adamkiewicz artery (AKA, arrow) and anterior spinal artery (ASA, arrow) in a 33-year-old man with a Crawford type II thoracoabdominal aortic aneurysm. Note that the Adamkiewicz artery and ASA are more difficult to depict with CTA compared with MRA owing to the lower contrast of the Adamkiewicz artery and ASA obtained with CTA.

Signal-to-noise ratio (SNR) and contrast-to-noise (CNR) of the Adamkiewicz artery vs the anteroposterior (AP) abdominal diameter (measured at T12). A, The SNR values of both the 80 kV (black circles) and the 120 kV (white circles) computed tomography angiography (CTA) protocols lie above that of magnetic resonance angiography (MRA) (squares). There is no influence of an increasing abdominal diameter on the SNR for MRA. This is in contrast to CTA where the SNR significantly decreases with increasing abdominal diameters. B, For the CNR, the MRA values lie above the values of both CTA protocols. Again there is no influence of an increasing abdominal diameter on the CNR MRA. This is in contrast to CTA, where the CNR significantly decreases with increasing abdominal diameters.