The use of appropriate calibration curves corrects for systematic differences in liver R2* values measured using different software packages*

摘要

Precise, reproducible measurements of liver iron concentration (LIC) are critical for the early diagnosis, treatment and follow-up of patients with primary or secondary iron overload. Magnetic resonance imaging (MRI), which exploits the paramagnetic properties of iron, has gained acceptance as a noninvasive and accurate tool for LIC assessment. Two different techniques have been described: methods measuring signal intensity ratio between liver and muscles (Gandon et al, 2004), and relaxometry methods measuring absolute R2 (St Pierre et al, 2005) or R2* (Wood et al, 2005) values, which increase proportionally to iron concentration. The gradient-echo R2* technique is most widely used in clinical practice (Anderson et al, 2001; Hankins et al, 2009; Meloni et al, 2011; Wood et al, 2005), because it is faster and easier than R2 acquisition.