Iron quantification can be performed using multiple gradient echo (GRE) images acquired with specific T1 and T2* weighting.
Specifically, the method, as described by Gandon et al., involves:
- Multiple Gradient Echo Images: Using a series of images acquired using GRE sequences. This allows for the capture of data that is sensitive to both T1 and T2* relaxation times.
- T1-weighted Images: These are acquired with a short echo time (TE) and a large flip angle. For instance, the reference specifies using images with a TE of 4ms and a flip angle of 90°.
- T2*-weighted Images: These are acquired with varying echo times (TE) to allow for the quantification of T2* relaxation times, which are affected by iron concentration. The reference specifies using images with TE values of 4, 9, 14, and 21ms, and a flip angle of 20°.
In summary, by analyzing the signal decay across the multiple echo times in the T2*-weighted images, one can quantify the iron concentration within the region of interest. The T1-weighted image provides additional anatomical context. This technique is commonly used in MRI to assess iron overload in organs like the liver.
