Characterization of liver tissue using Nakagami parameter imaging under different physiological and pathological conditions

Nakagami imaging has shown promise for liver assessment but has not been fully examined in clinical conditions. We evaluate the Nakagami shape parameter in 12 healthy volunteers under pre- and post-prandial conditions, in relation to other quantitative metrics, and in eight patients who underwent biopsy for diffuse liver disease or focal lesion assessment. In volunteers, nine measurements of Shear Wave Speed (SWS) and Dispersion (SWD) and five measurements of Attenuation (ATI) were acquired on a clinical scanner. In volunteers and patients, raw data were used to calculate the Nakagami parameter over a small sliding window, which was moved pixel-wise over an operator-selected area to obtain an average Nakagami parameter. No significant differences were observed between pre- and post-prandial quantitative values in volunteers (SWS: 1.37 ± 0.13 vs 1.35 ± 0.09 m/s, SWD: 11.5 ± 2.0 vs 11.1 ± 1.5 m/s/kHz, ATI: 0.54 ± 0.04 vs 0.53 ± 0.03 dB/cm/MHz, Nakagami: 0.82 ± 0.04 vs 0.84 ± 0.05). Only weak correlations were observed between the Nakagami parameter and the other metrics. In biopsy patients, the Nakagami parameter was significantly higher than in volunteers (0.90 ± 0.04, p < 0.05). Nakagami imaging appears robust to different physiological conditions and could be a useful marker of disease in patients.