130 Reproducibility of T1 and T2 Mapping in Health and Disease, and Assessment of T2 Variability Across the Normal Myocardium

Abstract

Background T1 and T2 mapping detect myocardial fibrosis and oedema respectively. T1 values show segmental variation in mid ventricular SAX slice, making the identification of regional pathology difficult.We tested the reproducibility of T1 and T2 mapping in health and disease and regional variations of T2 values. Methods Patients with non-ischaemic cardiomyopathy (NICM, n-10), ischaemic heart disease (IHD, n-10) and 10 controls underwent T1 and T2 mapping in a single SAX slice on a 3T scanner using MOLLI and T2 multi-echo sequence. Two independent observers measured T1 and T2 values from quantitative maps in six standardised regions of interest. Intra- and inter-observer reproducibility of T1 and T2 mapping was assessed using Bland-Altman plots and Pearson’s correlation. Results Age was significantly higher in IHD group (p < 0.05). Patients with NICM had increased EDV (p < 0.05), IHD patients had increased ESV (p < 0.05) and decreased EF (p < 0.05). Intra- and inter-observer agreements for T1 (r = 0.988; r = 0.965) and T2 (r = 0.978; r = 0.948) values across the whole cohort were very high (p < 0.001 for all agreements). Similarly, the intra- and inter-observer coefficients of variation (CoV) for T1 (0.66%; 1.19%) and T2 (1.85%; 2.5%) values were low. There was no significant difference between segmental T2 values in theSAX slice (p = 0.205). Conclusions T1 and T2 mapping are highly reproducible techniques. T2 maps show no segmentalvariation. Our study suggests that a single normal range of T2 values could be applied to the entire mid-ventricular SAX slice. Future work should aim to create a normal range of T2 values for this purpose.

Reproducibility of three different cardiac T2‐mapping sequences at 1.5T

“…Intra‐ and interobserver agreement for T 2 times acquired by manual segmentation of LV contours was excellent, which is in line with previous studies . Similar to the studies by Feng et al and Puntmann et al, interobserver variability exhibited slightly (although negligible) larger limits of agreement compared to intraobserver variability, which is to be expected when two different observers draw ROIs in a blinded fashion.…”

Outcomes of Cardiovascular Magnetic Resonance Imaging in Patients Recently Recovered From Coronavirus Disease 2019 (COVID-19)

“…Compared with healthy controls and risk factor–matched controls, patients recently recovered from COVID-19 had lower left ventricular and right ventricular ejection fraction, higher left ventricular volume, and raised native T1 and T2 measures. A total of 78 patients recently recovered from COVID-19 had abnormal CMR findings, including at least one of the following: raised myocardial native T1 (n = 73), raised myocardial native T2 (n = 60), myocardial LGE (n = 32), or pericardial enhancement (n = 22) (Figure 1). A total of 12 patients recently recovered from COVID-19 had an ischemic-type pattern of myocardial LGE.…”

“…Associations were explored using Pearson or Spearman correlation analyses, as appropriate for the type of data. Abnormal native T1 and T2 values were defined as greater than 1105 ms and greater than 37.4 ms, respectively, based on previously derived sequence-specific cutoffs of 2 SDs above the respective means in a healthy population . Significant abnormalities were defined as greater than 1136 ms for T1 and greater than 40 ms for T2, using 4 SDs above those means.…”

Cardiac T2 mapping: robustness and homogeneity of standardized in-line analysis

“…Magnetic field strength, sequence acquisition parameters, and post-processing algorithms have been shown to limit comparability among patients at different scanner sites or in longitudinal studies [11]. Published studies address reproducibility, robustness against artifacts, and faster image acquisition protocols [17][18][19][20][21]. Baessler and colleagues described a robust intra-individual reproducibility of T2 values over time, whereas the inter-individual differences were comparatively high and remained unclear [15].…”