Validation of T2∗in-line analysis for tissue iron quantification at 1.5 T

Background: there is a need for improved worldwide access to tissue iron quantification using t2∗ cardiovascular magnetic resonance (cmr). one route to facilitate this would be simple in-line t2∗ analysis widely available on mr scanners. we therefore compared our clinically validated and established t2∗ method at royal brompton hospital (rbh t2∗ ) against a novel work-in-progress (wip) sequence with in-line t2∗ measurement from siemens (wip t2∗ ). methods: healthy volunteers (n = 22) and patients with iron overload (n = 78) were recruited (53 males,median age 34 years). a 1.5 t study (magnetom avanto,siemens) was performed on all subjects. the same mid-ventricular short axis cardiac slice and transaxial slice through the liver were used to acquire both rbh t2∗ images and wip t2∗ maps for each participant. cardiac white blood (wb) and black blood (bb) sequences were acquired. intraobserver,interobserver and interstudy reproducibility were measured on the same data from a subset of 20 participants. results: liver t2∗ values ranged from 0.8 to 35.7 ms (median 5.1 ms) and cardiac t2∗ values from 6.0 to 52.3 ms (median 31 ms). the coefficient of variance (cov) values for direct comparison of t2∗ values by rbh and wip were 6.1-7.8 % across techniques. accurate delineation of the septum was difficult on some wip t2∗ maps due to artefacts. the inability to manually correct for noise by truncation of erroneous later echo times led to some overestimation of t2∗ using wip t2∗ compared with the rbh t2∗ . reproducibility cov results for rbh t2∗ ranged from 1.5 to 5.7 % which were better than the reproducibility of wip t2∗ values of 4.1-16.6 %. conclusions: iron estimation using the t2∗ cmr sequence in combination with siemens' in-line data processing is generally satisfactory and may help facilitate global access to tissue iron assessment. the current automated t2∗ map technique is less good for tissue iron assessment with noisy data at low t2∗ values. © 2016 alam et al.