Diagnostic Efficacy and Safety of Low-Contrast-Dose Dual-Energy CT in Patients With Renal Impairment Undergoing Transcatheter Aortic Valve Replacement

• Published in: Korean journal of radiology Vol. 25; no. 7; pp. 634 - 643
• Main Authors: Chang, Suyon, Jung, Jung Im, Beck, Kyongmin Sarah, Chang, Kiyuk, Kim, Yaeni, Han, Kyunghwa
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Radiology 01.07.2024; 대한영상의학회
• Subjects: Acute Kidney Injury - diagnostic imaging; Acute Kidney Injury - etiology; Aged; Aged, 80 and over; Aortic Valve Stenosis - diagnostic imaging; Aortic Valve Stenosis - surgery; Cardiovascular Imaging; Contrast Media; Female; Humans; Male; Radiation Dosage; Radiography, Dual-Energy Scanned Projection - methods; Renal Insufficiency; Reproducibility of Results; Retrospective Studies; Signal-To-Noise Ratio; Tomography, X-Ray Computed - methods; Transcatheter Aortic Valve Replacement - adverse effects; Transcatheter Aortic Valve Replacement - methods; 방사선과학; Computed tomography angiography; Transcatheter aortic valve replacement; Aortic valve stenosis; Contrast media; Monochromatic
• ISSN: 1229-6929; 2005-8330; 2005-8330
• DOI: 10.3348/kjr.2023.1207

This study aimed to evaluate the diagnostic efficacy and safety of low-contrast-dose, dual-source dual-energy CT before transcatheter aortic valve replacement (TAVR) in patients with compromised renal function. A total of 54 consecutive patients (female:male, 26:38; 81.9 ± 7.3 years) with reduced renal function underwent pre-TAVR dual-energy CT with a 30-mL contrast agent between June 2022 and March 2023. Monochromatic (40- and 50-keV) and conventional (120-kVp) images were reconstructed and analyzed. The subjective quality score, vascular attenuation, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were compared among the imaging techniques using the Friedman test and post-hoc analysis. Interobserver reliability for aortic annular measurement was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. The procedural outcomes and incidence of post-contrast acute kidney injury (AKI) were assessed. Monochromatic images achieved diagnostic quality in all patients. The 50-keV images achieved superior vascular attenuation and CNR ( < 0.001 in all) while maintaining a similar SNR compared to conventional CT. For aortic annular measurement, the 50-keV images showed higher interobserver reliability compared to conventional CT: ICC, 0.98 vs. 0.90 for area and 0.97 vs. 0.95 for perimeter; 95% limits of agreement width, 0.63 cm² vs. 0.92 cm² for area and 5.78 mm vs. 8.50 mm for perimeter. The size of the implanted device matched CT-measured values in all patients, achieving a procedural success rate of 92.6%. No patient experienced a serum creatinine increase of ≥ 1.5 times baseline in the 48-72 hours following CT. However, one patient had a procedural delay due to gradual renal function deterioration. Low-contrast-dose imaging with 50-keV reconstruction enables precise pre-TAVR evaluation with improved image quality and minimal risk of post-contrast AKI. This approach may be an effective and safe option for pre-TAVR evaluation in patients with compromised renal function.