TU‐D‐332‐02: Abdominal Fat Quantification Accuracy Using Water Saturated B‐SSFP MRI Sequences: A Verification Study

Abstract

Purpose: To verify the fat quantification accuracy of abdominal fat quantification results on images acquired with a Water Saturated b‐SSFP (WS b‐SSFP) MRI Sequence. Method and Materials: 10 healthy (5 female and 5 male) volunteers underwent both WS T1W TSE and WS b‐SSFP scans with breath hold on a 1.5 T clinical MR scanner. For the WS T1W TSE sequence, the parameters were as follows: TR/TE/flip angle = 500 ms/5 ms/90°, turbo factor = 7 and readout bandwidth = 128 KHz. For the WS 3D b‐SSFP sequences, the imaging parameters were as follows: TR/TE/flip angle = 2.9 ms/1.2 ms/55°, ETL = 128 with 12 dummy echoes, and readout bandwidth = 200 KHz. For WS T1W TSE sequence, 6 axial slices centered at L2‐L3 level were acquired in two consecutive expired breath‐holds, with 14 seconds each. Since WS b‐SSFP is a much faster scan, 8 slices (with slice 2–7 imaged at the same positions of the 6 TSE slices) were obtained in 11 seconds in one breath‐hold. For each subject, fat volumes from six common slices of WS TSE and WS b‐SSFP were measured and summed. Total abdominal fat (TAF), intra‐abdominal fat (IAF), and subcutaneous abdominal fat (SAF) volumes from images of both scans were measured and compared. Results: The TAF, IAF, and SAF mean differences of the fat volume measured from images of the two scans are only 0.34%, −0.25%, and 0.91%, respectively. The Bland‐Altman plots show that all the measurement differences between WS b‐SSFP and WS TSE are within the 95% of difference. Conclusion: The two methods are the same in terms of the measurement accuracy for human abdominal imaging. Therefore, WS b‐SSFP MRI can be used for abdominal fat quantification to reduce imaging and post‐processing difficulties and ultimately reduce research cost in abdominal fat distribution studies.