Non-contrast MRI protocol for TAVI guidance: quiescent-interval single-shot angiography in comparison with contrast-enhanced CT

Abstract

Objectives To prospectively compare unenhanced quiescent-interval single-shot MR angiography (QISS-MRA) with contrastenhanced computed tomography angiography (CTA) for contrast-free guidance in transcatheter aortic valve intervention (TAVI). Methods Twenty-six patients (mean age 83 ± 5 years, 15 female [58%]) referred for TAVI evaluation underwent QISS-MRA for aortoiliofemoral access guidance and non-contrast three-dimensional (3D) "whole heart" MRI for prosthesis sizing on a 1.5-T system. Contrast-enhanced CTA was performed as imaging gold standard for TAVI planning. Image quality was assessed by a 4point Likert scale; continuous MRA and CTA measurements were compared with regression and Bland-Altman analyses.Results QISS-MRA and CTA-based measurements of aortoiliofemoral vessel diameters correlated moderately to very strong (r = 0.572 to 0.851, all p ≤ 0.002) with good to excellent inter-observer reliability (intra-class correlation coefficient (ICC) = 0.862 to 0.999, all p < 0.0001) regarding QISS assessment. Mean diameters of the infrarenal aorta and iliofemoral vessels differed significantly (bias 0.37 to 0.98 mm, p = 0.041 to < 0.0001) between the two modalities. However, inter-method decision for transfemoral access route was comparable (κ = 0.866, p < 0.0001). Aortic root parameters assessed by 3D whole heart MRI strongly correlated (r = 0.679 to 0.887, all p ≤ 0.0001) to CTA measurements. Conclusion QISS-MRA provides contrast-free access route evaluation in TAVI patients with moderate to strong correlations compared with CTA and substantial inter-observer agreement. Despite some significant differences in minimal vessel diameters, inter-method agreement for transfemoral accessibility is strong. Combination with 3D whole heart MRI facilitates unenhanced TAVI guidance. Key Points • QISS-MRA and CTA inter-method agreement for transfemoral approach is strong. • QISS-MRA is a very good alternative to CTA and MRA especially in patients with Kidney Disease Outcomes Quality Initiative stages 4 and 5. • Combination of QISS-MRA and 3D "whole heart" MRI facilitates fully unenhanced TAVI guidance.

CT Image Feature Diagnosis on the Basis of Deep Learning Algorithm for Preoperative Patients and Complications of Transcatheter Aortic Valve Implantation

“…At present, the preoperative screening of patients to undergo CT plays an important role, which can be used to provide important information for clinical sheath approach. It also provides anatomical information for the weight of ascending aorta, the size of aortic root, and aortic ring [14]. TAVI requires preoperative examination to assess the size of aortic rings noninvasively and accurately, which is of great significance for the size selection of TAVI valve rings.…”

Valg av modalitet ved karundersøkelser: CTA vs. MRA

“…I 3 av de 4 studiene som så på kostnad var CTA billigst 17,19,20 men i den ene studien var 3D Time-of-flight magnetisk resonans angiografi (TOF MRA) billigst 21 . Syv studier fant at CTA er raskest 17,19,[22][23][24][25][26] men 1 studie med 3D TOF MRA fant at denne sekvensen hadde kortere skannetid enn CTA 21 .…”

“…Flere av respondentene kommenterte at kvalitet på undersøkelse hadde innvirkning på valg av modalitet. 7 studier fant at CTA hadde bedre fremstilling og bildekvalitet 17,19,22,24,[26][27][28] , mens 4 studier fant ingen stor forskjell 21,[29][30][31] . Ved 6 studier var den romlige oppløsningen best hos CTA 17,23,[25][26][27]31 , mens hos 1 studie med 3D TOF-MRA var den romlige oppløsningen bedre enn ved CTA 21 .En respondent uttrykte at CT ofte har den beste romlige oppløsningen som visualiserer mye detaljer.…”

“…7 studier diskuterer artefakter 17,19,[24][25][26]30,32 , og 3 av disse nevner artefakter fra både CTA og MRA 24,30,32 . 1 studie fant at 3T er bedre enn 1,5T på kontroll av coilede aneurismer, til tross for at den kan gi mer artefakter 32 .…”

“…11 studier påpeker at ioniserende stråling er en av ulempene med CTA [18][19][20][21][22][23][24]28,32,35,36…”