344 - Histotripsy in a Porcine Liver Model: Magnetic Resonance Imaging Radiologic-Pathologic Correlation

Wednesday, April 15, 2026

12:36 PM - 12:45 PM ET

Presenting Author(s)

AM

Ali Mutlu, MD

Research Intern
University of Wisconsin-Madison, United States

Author/Co-author(s)

EG

Edwarda Golden, MD

Assistant Professor
The Johns Hopkins Hospital, United States
CB

Charles Bradley, VMD

Assistant Professor
University of Pennsylvania School of Veterinary Medicine, United States
Emily A. Knott

Student
Cleveland Clinic Lerner College of Medicine, United States
Paul F. Laeseke, MD, PhD

Assistant Professor
University of Wisconsin, United States
JW

Jim White, BME

Lab Manager
University of Wisconsin - Madison, United States
FL

Fred T. Lee, Jr., MD

Professor
University Of Wisconsin, United States
Timothy J. Ziemlewicz, MD

Professor of Radiology
University of Wisconsin Hospital and Clinics, United States

Purpose: The purpose of this study is to define the correlation between the post-procedural imaging appearance of histotripsy treatment zones and corresponding pathologic specimens.

Materials and Methods: Eleven histotripsy treatment zones were created in ten healthy swine utilizing a clinical histotripsy unit (Histosonics, Plymouth, MN). Multiplanar, multisequence MRI (GE Healthcare, Waukesha, WI) was performed prior to and following the administration of gadobenate dimeglumine (MultiHance, Bracco, Germany) within one hour following treatment. Immediately following MRI, animals were sacrificed with livers harvested and fixed in formalin for 10-21 days before sectioning through the treatment zone for gross pathologic examination. ImageJ (NIH) was used to calibrate measurements on gross pathologic specimens using rulers embedded in each photograph. Orthogonal diameter measurements of each treatment zone, defined as M1 and M2 were then performed. Representative histologic sections were obtained from each treatment zone and margin. Based on the obtained sections, portal venous phase MRI series were reconstructed on a PACS station (Change Healthcare, Richmond, BC, Canada) to match the plane of gross pathologic sectioning utilizing the treatment zone, liver lobe edge, and adjacent blood vessels as internal fiducials. When an adequate registration was obtained, orthogonal measurements of the non-enhancing treatment zone were obtained in matching planes to the gross pathology, also defined as M1 and M2. Treatment zone areas were calculated using these linear measurements and modeled as an ellipse using the formula of ((M1)/2 * (M2)/2)*3.14159.

Results: The visible treatment zone at gross pathology was consistent with tissue necrosis at histologic analysis. There was a strong correlation between the cross-sectional area of MRI and gross pathology measurements (r2 = 0.70). The mean area difference between MRI and gross pathology was 0.1 cm2. The mean diameter differences between MRI and gross measurements were 0.03 cm for M1 and 0.04 cm for M2. There was a high correlation coefficient between both linear measurements and calculated area on MRI vs. gross pathology (r2 =0.70-0.75).

Conclusion: Contrast-enhanced MRI was a reliable biomarker for tissue necrosis following histotripsy in this normal animal model.