Low-tube-voltage CT assessment of Adamkiewicz artery: Precise comparison between 100-kVp- and 120-kVp protocols

Preoperative identification of Adamkiewicz artery (AKA) for preventing postoperative spinal cord ischemia is still challenging because of its small diameter. Low-tube-voltage technique might improve the delineation of AKA due to its higher contrast enhancement and contrast-to-noise ratio (CNR). Our purpose was to evaluate the usefulness of low-tube-voltage CTA in visualization of AKA compared with the conventional voltage protocol on the condition with the same imaging parameters aside from tube voltage.

Eighty-three patients undergoing CTA for the evaluation of aorta were retrospectively included. All CTA was performed with 320-detector-row CT with the tube voltage of either 100-kVp (41 patients) or 120-kVp (42 patients). The CNR, CT value of aorta and objective image noise were assessed. Visualization of AKA was evaluated based on the continuity from aorta using the four-grade score by two independent reviewers. The estimated radiation dose (volumetric CT dose index) was also compared.

The 100-kVp group showed significantly higher CNR and CT value than 120-kVp protocol (P =  0.010 and < 0.001, respectively). The visual score was also significantly higher in 100-kVp group than in 120-kVp group (2.73 ± 0.98 and 2.02 ± 1.00, respectively; P =  0.002). There was no significant difference on objective image noise and radiation dose between the groups (P =  0.24 and 0.72, respectively).

CTA with low-tube-voltage was significantly more sensitive for AKA visualization than conventional voltage protocol.