Fig. 5

Effect of TD and normal/short readout on segmental myocardial values in (a) females and (b) males (mean ± SD). Note the stronger effect of TD on T1 values in females than in the unselected population (see Fig. 3a), and lack of any relationship between TD and T1 values in males. Repeat analysis of segments from females by thickness showed that there was no significant difference in T1 values between diastolic and systolic readout in the thickest tertile (p = 0.06), but there was an exaggerated difference for the thinnest tertile (p < 0.001) (c). This suggests that increased partial-volume effects in diastole (particularly in thinner myocardial segments) are responsible for the gender effect and the relationship between TD and T1 values. Systolic readout was defined as TD 0–150 ms and diastolic readout as TD 340 ms and “end diastole”. The cutoffs for tertiles of female myocardial segmental thickness were defined based on the conventional ShMOLLI sequence thickness in the included female volunteers (<2.97 mm for lowest tertile and > 3.87 mm for highest tertile)