S index: a predictor comparable to ultrasound shear wave elastography in assessing liver fibrosis in patients with chronic hepatitis B. - Sujuan Guo; Lu Gan; Feng Du; Qiang Feng; Jiahua Li; Qinyun Wan; Qiannan Meng; Yaoren Zhang; Yonghao Ji; Jianxue Liu (BMC Medical Imaging, 2025)