Assessing the Impact of Imaging Parameters on the Measurement of Kidney T2

Motivation: Renal T2-mapping can provide measures of kidney inflammation and oedema, but few studies include T2-mapping due to a lack of consensus on image parameters. Goal(s): To compare the accuracy, sensitivity to B0/B+1, and influence of flow of our four renal T2-mapping sequences; SE-EPI, ME-SE, GraSE and T2-prepared EPI. Approach: Each T2-mapping sequence is used to image the ISMRM/NIST phantom T2 spheres with controlled modulation of the B0 and B+1 field, a flow phantom and eight healthy volunteers. Results: For renal T2-mapping we recommend a multi-echo sequence with short echo spacing, sampling TE up to 140 ms at 3T. Impact: This work provides recommendations for researchers to perform T2-mapping in renal MRI studies. It highlights key imaging parameters that should be optimised and advantages/disadvantages related to accuracy, dependence on B0 and B+1 fields and flow of common T2-mapping sequences.