Objective: Purpose of our study was to demonstrate the feasibility and limitations of acoustic noise reduction in a standard clinical MRI protocol for abdominal imaging.
Methods: Acoustic noise and image quality were assessed in 17 patients for a standard liver imaging protocol including TSE and GRE sequences and compared to quiet optimizations as described by Heismann et al. Two blinded readers scored artifacts, the delineation of the abdominal organs and level of diagnostic confidence. Means of the sound level measurements, the ratings and the measurement of SNR and CNR were compared.
Results: Significant reduction of acoustic noise was measured for T2 TSE (-30.7%), T2 HASTE (-22.6%) and less difference for T1 DIXON (-4.7%) and T1 FLASH (-2.7%). SNR and CNR were lower for quiet T2 TSE (-18.0%, -23.1%) and T2 HASTE (-46.2%, -37.7%) and higher for T1 DIXON (+32.0%, +24.4%). Inter-rater correlation was k = 0.987 with p < 0.001.
Conclusions: Although sequence-based noise optimizations faces problems in T1 FLASH and DIXON sequences, there is an important acoustic benefit in T2 TSE and T2 HASTE sequences, which goes along with a maintained image quality and diagnostic confidence.
Keywords: Acoustic noise reduction; Image quality; Patient comfort; Quiet MRI.