In Vitro Model Employing Contrast-enhanced Ultrasound (CEUS) for the Simulation of Radiologic Intraoperative Liver Punctures and Biopsies

To develop a training model for contrast-enhanced ultrasound (CEUS)-guided biopsy during the learning phase. An in-vitro model using porcine liver with olive-shaped lesions marked by pepper seeds was employed to simulate tumor biopsies. After targeted injection of sulfur-hexafluoride microbubbles as contrast agent, both native and CEUS-guided biopsies were performed using 18G core needles. Linear transducers of a high-end ultrasound device (3–15 MHz) and of a portable handheld ultrasound device (3–12 MHz) were utilized. Freehand biopsies were conducted both in-plane and out-of-plane. Twelve procedures each were performed by experienced and novice examiners on lesions located at depths of 2–4 cm, with comparisons made regarding procedure duration and image quality. Image and procedure quality were assessed by two independent readers using a scale from 0 (insufficient) to 5 (excellent). CEUS enabled more precise localization and marking of poorly delineated lesions, thereby facilitating targeted biopsy, even in deeper tissue layers. Particularly under challenging acoustic conditions, CEUS improved the planning and execution of interventions for both experienced and novice users when using handheld ultrasound devices. In this in-vitro study, CEUS provided a significant advantage for experienced users working with handheld systems (p < 0.05), whereas its integration into high-end systems did not lead to a significant difference in procedure time (p > 0.05). Novice users, however, benefited significantly from CEUS when using high-end systems (p < 0.01). CEUS-marked lesions in the in-vitro model allow for realistic training of targeted punctures and biopsies – even for lesions not clearly visible in B-mode imaging. Despite the absence of circulation, the contrast effect remains sufficiently stable to practice CEUS techniques under conditions closely resembling clinical practice. This supports the safe application of portable ultrasound systems in interventional procedures.