Technical report|Articles in Press

Importance of imaging-acquisition protocol and post-processing analysis for extracellular volume fraction assessment by computed tomography

Published:March 13, 2023DOI:



      Computed tomography angiography (CTA) assessment of myocardial extracellular volume fraction (CT-ECV) is feasible, although the protocols for imaging acquisition and post-processing methodology have varied. We aimed to identify a pragmatic protocol for CT-ECV assessment encompassing both imaging acquisition and post-processing methodologies to facilitate its clinical implementation.


      We evaluated consecutive patients with severe aortic stenosis undergoing evaluation for transcatheter aortic valve replacement (TAVR). Pre-contrast and 3-min-delayed CTA were obtained in systole using either helical prospective-ECG-triggered (high-pitch) or axial sequential-ECG-gated acquisition, adding to standard TAVR CTA protocol. Using a dedicated software for co-registration of CTA datasets, three methodologies for ECV measurement were evaluated: (1) mid-septum region of interest (Septal ECV), (2) averaged-global ECV (Global ECV) encompassing 16-AHA segments, and (3) average of septal and lateral segments (Averaged ECVsep and Averaged ECVlat).


      Among the 142 patients enrolled (median ​= ​81 years, 44% females), 8 were excluded due to significant imaging artifacts precluding Global ECV assessment. High-pitch scan mode was performed in 68 patients (48%). Suboptimal image quality for Global ECV assessment was associated with high-pitch scan mode (odds ratio: OR ​= ​2.26, p ​= ​0.036), along with the presence of intracardiac leads (OR ​= ​4.91, p ​= ​0.002), and BMI≥35 ​kg/m2 (OR ​= ​2.80, p ​= ​0.026). Septal ECV [median ​= ​29.4%] and Averaged ECVsep [29.0%] were similar (p ​= ​0.108), while Averaged ECVlat [27.5%] was lower than Averaged ECVsep (p ​< ​0.001), resulting in lower Global ECV [28.6%].


      Myocardial CT-ECV assessment is feasible using a systolic sequential acquisition pre-contrast, and similar additional 3-min delayed scan. Septal ECV measurement provides similar values to Global ECV and is equally reproducible.



      AF (atrial fibrillation), AS (aortic stenosis), BMI (body mass index), CTA (computed tomography angiography), ECV (extracellular volume fraction), ECG (electrocardiography), MRI (magnetic resonance imaging)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      Full access to the journal is a member benefit for SCCT Members, Login via the SCCT website to access all journal content.


      Subscribe to Journal of Cardiovascular Computed Tomography
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Tamarappoo B.
        • Han D.
        • Tyler J.
        • et al.
        Prognostic value of computed tomography–derived extracellular volume in TAVR patients with low-flow low-gradient aortic stenosis.
        JACC: Cardiovasc Imag. 2020; 13: 2591-2601
        • Scully P.R.
        • Patel K.P.
        • Saberwal B.
        • et al.
        Identifying cardiac amyloid in aortic stenosis: ECV quantification by CT in TAVR patients.
        JACC: Cardiovasc Imag. 2020; 13: 2177-2189
        • Bhuva A.N.
        • Treibel T.A.
        • Seraphim A.
        • et al.
        Measurement of T1 mapping in patients with cardiac devices: off-resonance error extends beyond visual artifact but can Be quantified and corrected.
        Front Cardiovasc Med. 2021; 8
        • Gama F.
        • Rosmini S.
        • Bandula S.
        • et al.
        Extracellular volume fraction by computed tomography predicts long-term prognosis Among patients with cardiac amyloidosis.
        JACC: Cardiovasc Imag. 2022; 15: 2082-2094
        • Bandula S.
        • White S.K.
        • Flett A.S.
        • et al.
        Measurement of myocardial extracellular volume fraction by using equilibrium contrast-enhanced CT: validation against histologic findings.
        Radiology. 2013; 269: 396-403
        • Treibel T.A.
        • Bandula S.
        • Fontana M.
        • et al.
        Extracellular volume quantification by dynamic equilibrium cardiac computed tomography in cardiac amyloidosis.
        J Cardiovasc Comput Tomogr. 2015; 9: 585-592