Standardization of T1-mapping in cardiovascular magnetic resonance using clustered structuring for benchmarking normal ranges

INTERNATIONAL JOURNAL OF CARDIOLOGY

卷:326

Article

Popescu, Iulia A.¹  Werys, Konrad¹  Zhang, Qiang¹  Puchta, Henrike¹  Hann, Evan¹  Lukaschuk, Elena¹  Ferreira, Vanessa M.¹  Piechnik, Stefan K.¹ 

[1] Univ Oxford, Oxford Ctr Clin Magnet Resonance Res OCMR, Radcliffe Dept Med, Div Cardiovasc Med, Oxford, Oxon, England

关键词: T1-mapping;    MOLLI;    Normal controls;    Native T1;    Standardization;    Clustering;   

DOI  :  10.1016/j.ijcard.2020.10.041

来源: Elsevier

【 摘 要 】

Background: Cardiovascular magnetic resonance T1-mapping is increasingly used for tissue characterization, commonly based on Modified Look-Locker Inversion recovery (MOLLI). However, there are numerous MOLLI variants with differing normal ranges. This lack of standardization presents confusion and difficulty in inter-center comparisons, hindering widespread adoption of T1-mapping. Methods: To address this, we performed a structured literature search for native left ventricular myocardial T1-mapping in healthy humans measured using MOW variants at 1.5 and 3 Tesla, across scanner vendors. We then used k-means clustering to structure normal MOLLI-T1 values according to magnetic field strength, and investigated correlations between common imaging parameters: repetition time (TR), echo time (TE), flip angle (FA). Results: We analyzed data from 2207 healthy controls in 76 independent reports. Normal MOLLI-T1 standard deviations varied by 11-fold, and dependencies on TE, IR. and FA differed between 1.5 T and 3T, thwarting meaningful T1 standardization even within a single field strength, including the use of Z-score. However, divergent MOLLI-T1 norms may be structured using data clustering. For 15 T. two dusters emerged: Cluster1(1.5T): T1 = 958 +/- 16 ms (n = 1280): Cluster2(1.5T): T1 = 1027 +/- 19 ms (n = 386). For 3 T, three dusters emerged: Cluster1(3T): T1 = 1160 +/- 21 ms (n= 330); Cluster2(3T): T1 = 1067 +/- 18 ms (n = 178); Cluster3(3T) : T1 = 1227 = 19 ms (n = 41). We then propose the concept of an online calculator for assigning local norms to a known MOW TI cluster, allowing benchmarking against published norms. Conclusion: Clustered structuring allows T1 standardization of widely-divergent MOLLI variants, benchmarking local norms (usually based on smaller samples) against published norms (larger samples). This may increase confidence and quality control in method implementation, facilitating wider clinical adoption of T1-mapping. (C) 2020 The Authors. Published by Elsevier B.V.

【 授权许可】

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