Feasibility of combined ECG-Gated and Helical acquisition mode in a pre-TAVI computed tomography angiography protocol using a fixed low-volume contrast medium injection

• Published in: European journal of radiology 2020-10, Vol.131, p.109239, Article 109239
• Main Authors: Gallo, Giuseppe S., Gerasia, Roberta, Caruso, Calogero, Tafaro, Corrado, Iannazzo, Erica, Cannataci, Christine, Gentile, Giovanni, Mamone, Giuseppe, Gandolfo, Caterina, Miraglia, Roberto
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Aorta - surgery; Aortic Valve Stenosis - diagnostic imaging; Aortic Valve Stenosis - surgery; Body Mass Index; Clinical Protocols; Computed Tomography Angiography - methods; Contrast injection; Contrast Media - administration & dosage; Contrast-induced acute kidney injury; CT angiography; Electrocardiography; Feasibility Studies; Female; Humans; Iodine; Male; Prospective Studies; Signal-To-Noise Ratio; Transcatheter aortic valve implantation; Transcatheter Aortic Valve Replacement
• ISSN: 0720-048X; 1872-7727
• DOI: 10.1016/j.ejrad.2020.109239

To investigate the feasibility, image quality, and clinical implications of a combined ECG-gated and helical acquisition mode in a computed tomography angiography (CTA) protocol in patients scheduled for transcatheter aortic valve implantation (TAVI) using a fixed, low-volume, contrast medium injection. Between July and October 2019, 43 TAVI candidates underwent investigation with CTA using a 64-slice CT scanner. Images obtained were prospectively evaluated. 65 mL of low iodine dose contrast medium (CM), followed by 25 mL of saline, were administered using a fixed multiphasic injection protocol in all patients. Patients were divided into three groups based on BMI: Group 1 (n = 9) with BMI  29 kg/m2. Images were evaluated for image quality, vessel attenuation (HU), Signal-to-Noise Ratio (SNR), Contrast-to-Noise Ratio (CNR) and estimated radiation dose. Image quality of the aortic root and iliac-femoral vessels was diagnostic in all patients. Vascular attenuation was > 200 HU and CNR > 3 at all vessel levels. Data from our study suggest that it is possible to image the aortic annulus and aorto-iliac anatomy and obtain high image quality in all patients by using a combined ECG-gated and helical acquisition mode in a computed tomography angiography (CTA) protocol with a fixed low-volume contrast medium injection (65 mL). This allows for accurate CT measurements of the aortic annulus, recruitment of patients for TAVI and facilitates pre-procedural planning in these high surgical risk patients.