ARRS 2022 Abstracts

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1818. DECT Angiography May Significantly Lower Contrast Dose for Patients at Risk for Contrast-Induced Nephropathy Compared to SECT Angiography
Authors * Denotes Presenting Author
  1. Abdullah Memon *; University of Illinois
  2. Jonathan Fergus; University of Chicago
  3. Osmanuddin Ahmed; University of Chicago
  4. Pritesh Patel; University of Chicago
Objective:
This study aims to compare Dual Energy CT (DECT) angiography using reduced intravenous iodinated contrast dose compared to single-energy CT (SECT) angiography in patients at risk.

Materials and Methods:
Forty-nine patients at risk for contrast-induced nephropathy were referred from the vascular surgery clinic for DECT angiography with approximately 80 mL of iodinated contrast in a prospective fashion.  Thirty-three of these patients had a prior SECT aortography using 90-120 ml of iodinated contrast, and these patients were used for pair-matched controls. Voltage settings for DECT aortography were 50 and 70 keV whereas the voltage for SECT aortography was 120 kVp. Patient demographics, iodine dose, mean aortic attenuation in Hounsfield units (HU), and image noise were collected and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. ANOVA and paired t-tests were used to compare DECT to SECT.

Results:
On average, patients were 65 years of age with a mean BMI of 27.6 kg/m2. 67% were male and 33% were female. Average creatinine and GFR were 1.37 mg/dL and 64 mL/min, respectively. Mean iodine dose was 109.9 mL for SECT and 82.3 mL for DECT, a 25% reduction. The mean aortic attenuation was significantly higher for DECT 50 keV (736 ± 228 HU) compared to SECT 120 kVp (350 ± 98 HU) (p < 0.001) while mean aortic attenuation for DECT 70 keV (370 ± 97 HU) was not significantly different from SECT 120. Measured image noise was greatest for DECT 50 keV (-1022 ± 64 HU) and was lowest for SECT (-990 ± 24 HU, p = 0.009). When compared to SECT, the SNR and CNR for DECT 50 keV was significantly higher (p < 0.001 and p < 0.001, respectively) while the SNR and CNR for DECT 70 keV was not significantly different (p = 0.627 and p = 0.569, respectively).

Conclusion:
DECT angiography with 25% reduced iodine dose increased contrast attenuation, SNR, and CNR at 50 keV when compared to standard iodine SECT aortography at 120 kVp.