Standing Position Ultrasonography: Imaging Efficacy in Detecting Liver Diaphragmatic Dome Blind Area Lesions

Objective: To compare the detection efficacy of standing, supine, and left lateral decubitus ultrasonographic scanning for space-occupying lesions ≤3cm in the liver dome "blind area" and assess the feasibility of standing position as a routine scanning posture, providing a theoretical basis for optimizing liver ultrasound protocols. Methods: Prospectively enrolled patients (CT/MRI-confirmed liver dome lesions) admitted to our Hepatobiliary-Pancreatic Department (Feb 2024-Feb 2025). Three sonographers, blinded to other positions' results, performed scans in standing, supine, and left lateral positions. Fleiss' kappa assessed inter-sonographer agreement. An image quality scoring system (0=not visible; 1=partially visible; 2=fully visible) was used by two blinded radiologists. Baseline data (sex, age, BMI), lesion location, size, type, and liver parenchymal status (normal, fatty liver, liver damage \[diffuse disease/cirrhosis\]) were recorded. Wilcoxon test compared display scores. Subgroup analyses evaluated confounding factors. A Generalized Estimating Equations (GEE) model controlled repeated-measures bias, reporting ORs.