The Reproducibility of Myocardial and Liver T2* for Iron Load Quantification – A Dual-Center Multi-Platform Study

Abstract Description

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Authors (including presenting author) :

VSH Chan (1), L Yip (1), CWS Chan (2), KT Wong (3), W Kwong (3), YY Law (3), M Lai (3), A Wat (3), SCW Cheung (1)

Affiliation :

(1) Department of Radiology, Queen Mary Hospital, (2) Department of Medicine, Queen Mary Hospital, (3) Department of Imaging and Interventional Radiology, Prince of Wales Hospital

Introduction :

T2* relaxation refers to the decay of transverse magnetization caused by spin-spin relaxation and magnetic field inhomogeneity, with an inverse relationship to intracellular iron stores. The measurement of ventricular function and T2* levels in the myocardium and liver are hence essential in the management of the iron-overload.This is particularly important in transfusion-dependent thalassaemia major, a disease common in Asia.

Objectives :

Patients may sometimes be treated at more than one centre, and the reproducibility of T2* is paramount in tailoring the appropriate treatment regimen. In addition, the authors sought to evaluate if pre-existing workstations could replace third-party post-processing applications in the measurement of T2* for improved cost efficiency, particularly if the values were reproducible across various platforms.

Methodology :

Clinical data was retrospectively collected from 50 patients who underwent magnetic resonance imaging (MRI) for iron quantification (myocardium and liver) at two major tertiary referral radiology departments in Hong Kong – namely, Queen Mary Hospital (QMH) and Prince of Wales Hospital (PWH). The QMH group had 25 patients with MRI performed on the Siemens 1.5T MAGNETOM Aera scanner (Siemens Healthcare, GmbH ©2018). The PWH group had 25 patients with MRI performed on the Philips 1.5T Ingenia scanner (Koninklijke, Philips N.V. 2004-2018). Acquired T2* values from the QMH group were compared between those obtained from the syngo®.via workstation and values obtained on CMRtools™ (Cardiovascular Imaging Solutions Ltd). Acquired T2* values from the PWH group were compared between those obtained from the Philips IntelliSpace Portal workstation and values obtained on CMRtools™. Intra and inter-observer agreement were also assessed in the data collected from the QMH group.

Result & Outcome :

Good agreement was noted between the various quantitative platforms for T2* measurements of the myocardium and liver in both the QMH and PWH groups. Excellent intra-class correlation coefficient values were obtained for intra and inter-observer agreement by both measurement platforms in the QMH group. T2* measurements are hence deemed reproducible and consistent on multiple platforms in our dual-center study, with excellent intra and inter-observer agreement. With these results, subsequent measurements can be performed on native pre-existing worsktations without the utilisation of third-party post-processing software.