Computed Tomographic Angiography of the Abdomen and Pelvis in Azotemic Patients Utilizing 80-kV(p) Technique and Reduced Dose Iodinated Contrast: Comparison With Routine 120-kV(p) Technique. Issue 1 (January 2017)

• Record Type: Journal Article
• Authors: Knipp, David; Lane, Barton F.; Mitchell, Jason W.; Daly, Barry D.
• Is Part Of: Journal of computer assisted tomography. Volume 41:Issue 1(2017)
• Publication Date: 2017-01
• Subjects: CT angiography -- low kV -- iodinated contrast -- iterative reconstruction -- image quality; Tomography -- Periodicals; Tomography -- Periodicals; Tomography; Periodicals; 616.0757
• DOI: 10.1097/RCT.0000000000000478
• Languages: English
• ISSNs: 0363-8715

Abstract

Abstract : Objective: To evaluate image quality (IQ) of a reduced contrast volume, low kilovolt (peak) [kV(p)] abdominopelvic computed tomographic angiography (AP-CTA) protocol compared to a standard 120-kV(p) AP-CTA protocol. Methods: A retrospective image analysis was performed on 103 patients with end-stage renal disease who underwent AP-CTA. Forty-nine patients were scanned at 80 kV(p) with a mean of 48 mL of contrast, and 54 patients were scanned at 120 kV(p) with a mean of 98 mL of contrast. Objective comparison of arterial attenuation, noise, and contrast-to-noise ratio was obtained, in addition to radiation dose. Subjective assessment of IQ, enhancement intensity, and image noise (IN) was scored on a 3-point scale. Results: The 6-level aggregate contrast-to-noise ratio for the 80-kV(p) group was 11.8 ± 7.0, compared to 12.4 ± 4.6 in the 120-kV(p) group ( P = 0.210). Radiation exposure was significantly lower in the 80-kV(p) group versus the 120-kV(p) group, as measured by average CT dose index (mGy) of 9.0 ± 3.1 and 15.8 ± 5.8 ( P < 0.0001), respectively; and average dose length product (mGy × cm) of 490.0 ± 214.1 and 863.1 ± 344.4 ( P < 0.0001), respectively. The 120-kV(p) technique scored better for subjective IQ ( P = 0.042) and IN ( P = 0.004) but not for enhancement intensity ( P = 0.205). Conclusions: A 50% reduced iodinated contrast dose coupled with 80-kV(p) technique with iterative reconstruction allows for satisfactory AP-CTA studies at a 43% mean radiation dose reduction compared to a standard protocol. Negative but potentially reversible sequelae of this drop in radiation dose include increased IN and reduced subjective IQ.