320-row CT transcatheter aortic valve replacement planning with a single reduced contrast media bolus injection.

Daddy Mata-Mbemba,Patrick Ohlmann,Aissam Labani,Mi-Young Jeung,Catherine Roy,Soraya El Ghannudi,Mickaël Ohana,Mickaël Ohana,Mickaël Ohana

doi:10.1371/journal.pone.0204145

Abstract

ObjectiveTo reduce the iodine load required for CT Transcatheter Aortic Valve Replacement (TAVR) planning on a 320-row scanner by acquiring the two CT TAVR steps (ECG-gated aortic root CTA and non-gated aorto-ilio-femoral CTA) within a single contrast media bolus injection.Methods50 consecutive patients (82.6±6.9 years; 56% female) were prospectively enrolled and underwent a TAVR planning using a 320-row CT, with ECG-gated aortic root CTA immediately followed by a non-gated aorto-iliac acquisition, all within a single bolus of 40-70mL of Iohexol 350mgI/mL. The Iodine load, image quality, SNR, CNR and radiation dose were compared using a Mann-Whitney test to that of 24 consecutive patients (84.3±4.8 years, 58% female) previously imaged on a 64-row scanner with a conventional two-step protocol.ResultsIodine load was reduced by 44%. All examinations were of diagnostic quality, with improvement of the aortic root CTA image quality (4.9±0.3 versus 4.6±0.5, p<0.01) and a non-significant decrease of the aorto-iliac CTA image quality (4.7±0.6 versus 4.9±0.3, p = 0.07). SNR and CNR were significantly improved in the aortic root CTA (14.0±5.3 and 10.4±4.5 versus 10.3±4.2 and 6.8±3.3, p<0.01 for both) and non-significantly higher in the aorto-iliac CTA (16.5±8.0 and 14.1±7.9 versus 14.7±5.5 and 12.5±5.0, p = 0.42 and p = 0.66). Total radiation dose was reduced by 32%.Conclusion320-row CT scanner enables a 44% reduction of iodine load in TAVR planning, while maintaining excellent aorto-ilio-femoral arterial enhancement and lowering radiation dose.

Highlights

Aortic stenosis is the third most prevalent cardiovascular disease worldwide [1], with a poor natural prognosis since the survival rate of untreated patients with symptomatic severe stenosis is 60% at 1 year and 32% at 5 years [2]
signal-to-noise ratio (SNR) and contrast-tonoise ratio (CNR) were significantly improved in the aortic root Computed Tomography Angiography (CTA) (14.0±5.3 and 10.4±4.5 versus 10.3±4.2 and 6.8±3.3, p
We have demonstrated in this study that the second generation 320-row CT could achieve a complete Transcatheter Aortic Valve Replacement (TAVR) CT workup with acquisition of the ECG-gated aortic root followed by the aorto-ilio-femoral CTA within one single iodine contrast media (CM) bolus injection, resulting in a significant (44%) reduction of the total iodine load, with a mean iodine dose of 23.6g

Summary

Introduction

Aortic stenosis is the third most prevalent cardiovascular disease worldwide [1], with a poor natural prognosis since the survival rate of untreated patients with symptomatic severe stenosis is 60% at 1 year and 32% at 5 years [2]. Using a 64 or a 128-row single source scanner, a comprehensive TAVR planning protocol commonly requires two consecutive steps: a retrospectively ECG-gated aortic root CTA first, followed by an ungated aorto-ilio-femoral CTA [10, 11]. For each of both steps, a bolus injection of 30 to 90mL of iodine contrast media (CM) is required, bringing the total amount of CM delivered up to 180mL. Various strategies have been described through the literature to reduce to the strict minimum the quantity of iodine CM required for CT TAVR planning

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Conclusion