The feasibility of a 64-slice MDCT for detection of the Adamkiewicz artery: comparison of the detection rate of intravenous injection CT angiography using a 64-slice MDCT versus intra-arterial and intravenous injection CT angiography using a 16-slice MDCT

Abstract

Identification of the Adamkiewicz artery (AKA) using CT angiography (CTA) is crucial in patients with thoracic aortic aneurysm (TAA) or aortic dissection (AD). The purpose of this study was to compare the AKA detection rate of intravenous injection with a 64-slice MDCT (IV64) versus a 16-slice MDCT (IV16) as well as by CTA using intra-arterial injection with a 16-slice MDCT (IA16). A retrospective review of 160 consecutive patients who underwent CTA was performed. There were 108 TAA and 52 AD cases, 105 of whom were examined with IV64, 15 with IV16, and 40 with IA16. The AKA detectability for each imaging method was assessed, and the factors influencing the detectability were analyzed by multivariate analysis. The detection rates for IV64, IV16, and IA16 were 85.7, 60.0, and 80.0 %, respectively, with IV64 being more sensitive than IV16 (P = 0.025). The detection rate for AD patients was 66.7 % with IV64, which was similar to IV16 (57.1 %) and IA16 (66.8 %). On the other hand, the detection rate for TAA patients was 93.3 % with IV64, which was higher than IV16 (62.5 %, P = 0.021) and similar to IA16 (88.0 %). Multivariate analysis demonstrated the independent factors for AKA detectability were TAA versus AD (P = 0.005, Odds ratio = 3.98) and IV64 versus IV16 (P = 0.037, Odds ratio = 4.03). The detection rate was higher for IV64 than for IV16, especially for TAA patients, while the rate was similar between IV64 and invasive IA16. A 64-slice MDCT thus provides a less invasive visualization of the AKA.

Advantages of 70-kV CT Angiography for the Visualization of the Adamkiewicz Artery: Comparison with 120-kV Imaging

“…ever, the anatomic features of the AKA-a small vessel surrounded by osseous structures-may frequently be obscured in the contrast-to-noise ratio (CNR) of the spinal vasculature. 7 A higher contrast-to-noise ratio in spinal CTA has previously been achieved with a high tube current-time product with a slow rotation speed and a small helical pitch to reduce image noise, 8 and CTA with intra-arterial injection has been used to increase the contrast of the vessel. 7,9,10 Consequently, the detection rate of the AKA has been improved to 85%-100% 7,8,[10][11][12] ; however, these techniques require either high radiation exposure or the insertion of a pigtail catheter into the pathologic aorta.…”

“…7 A higher contrast-to-noise ratio in spinal CTA has previously been achieved with a high tube current-time product with a slow rotation speed and a small helical pitch to reduce image noise, 8 and CTA with intra-arterial injection has been used to increase the contrast of the vessel. 7,9,10 Consequently, the detection rate of the AKA has been improved to 85%-100% 7,8,[10][11][12] ; however, these techniques require either high radiation exposure or the insertion of a pigtail catheter into the pathologic aorta. 8 Seventy-kilovolt CT can substantially increase vascular iodine enhancement compared with conventional 120-kV imaging because the effective photon energy achieved with a 70-kV scan lies in the range of maximum absorption close to the K-edge of iodine (33.2 keV).…”

Bone-Subtracted Spinal CT Angiography Using Nonrigid Registration for Better Visualization of Arterial Feeders in Spinal Arteriovenous Fistulas

“…High-radiation-dose imaging is usually needed for the detection of feeders of SAVFs. Although dual-phase spinal CTA had been reported beneficial for avoiding contamination between the radiculomedullary arteries and veins, 9,17,20 its contribution to detecting the feeders of SAVFs is not fully understood. However, accurate preangiographic detection of the location of the feeders is associated with a reduction of approximately half of the following fluoroscopy time.…”

“…17 The parameters were set as follows: 0.5-mm collimated section width, 0.60 seconds per rotation, 0.641 pitch, 120 kV, and 400 mAs. Iopamidol at 370 mg I/mL (Iopamiron 370; Bayer Yakuhin, Osaka, Japan) was injected via a 20-ga catheter in the right antecubital vein (100 mL, 5 mL/s), followed by a 30-mL saline flush.…”

Spatial resolution measurement for iterative reconstruction by use of image-averaging techniques in computed tomography

“…Multidetector computed tomography (MDCT) has played an important role in diagnostic imaging; it is increasingly being used because it can quickly and accurately help diagnose various diseases [1][2][3]. However, the increase in CT examinations prompts the need for a discussion of radiation risks versus medical benefits [4].…”