Illustration of flooded lung with ultrasound beams targeting liver.

Flooded Lung Breakthrough: A New Pathway for Liver Ultrasound Therapy?

Lena Kashyap in Health & Wellness November 2025 • 4 min read.

"Could a technique using flooded lungs revolutionize how we treat liver tumors with High-Intensity Focused Ultrasound (HIFU)?"

In recent years, High-Intensity Focused Ultrasound (HIFU) has emerged as a promising, non-invasive method for treating liver malignancies. This innovative approach allows doctors to target and destroy tumors without the need for traditional surgery, reducing risks and recovery times for patients.

However, there are challenges. Tumors located in the liver dome, the uppermost region of the liver, are difficult to treat with HIFU due to the presence of the adjacent lung. The air-filled lung acts as a barrier, blocking ultrasound waves and preventing them from reaching the tumor effectively. This limitation has spurred researchers to find creative solutions to overcome this acoustic obstacle.

One such solution is 'one-lung flooding' (OLF), a technique that involves filling one lung with a saline solution. This enables complete sonography of the lung and adjoining organs, including the liver. Filling the lung with fluid creates a clear pathway for ultrasound waves, allowing for more precise and effective HIFU ablation of liver tumors. In this study, we explore the feasibility of ultrasound-guided transthoracic, transpulmonary HIFU ablation of the liver using OLF.

One-Lung Flooding: A Novel Approach to Liver Tumor Treatment

Illustration of flooded lung with ultrasound beams targeting liver.

Researchers are exploring one-lung flooding (OLF) as a way to enhance the effectiveness of High-Intensity Focused Ultrasound (HIFU) for treating liver tumors located in challenging areas. This method involves temporarily filling one lung with saline solution to create a clear acoustic pathway for the ultrasound waves.

The study involved using ultrasound-guided HIFU to create thermal lesions in the livers of three pigs after inducing right-side lung flooding. The HIFU beam was directed transthoracically (through the chest wall) and transpulmonarily (through the lung) towards the liver, targeting five different locations: two on the liver surface and three deeper within the tissue.

Lung Preparation: The right lung was carefully filled with a degassed and tempered isotonic saline solution, matching the functional residual capacity and tidal volume of a pig lung.
HIFU Application: After carefully preparing and positioning the animal, the researchers used a diagnostic imaging system to visualize the flooded lung and liver. A specialized HIFU applicator was then used to deliver targeted ultrasound energy to create thermal lesions in the liver tissue.
Lesion Creation: The HIFU focus was carefully positioned within the liver under constant imaging control, ensuring a direct pathway through the flooded lung and diaphragm. The liver tissue was exposed to HIFU for five seconds, with breath-holding periods to minimize movement.

Following the procedures, the scientists conducted thorough autopsy examinations, meticulously inspecting the lungs, diaphragm, and liver. Histological analyses were performed to evaluate the created focal liver lesions and any potential impact on the lung tissue. The results indicated that fifteen thermal liver lesions were successfully created via transpulmonary HIFU sonication across all targeted regions.

The Future of Liver Tumor Treatment

The study concludes that flooded lung provides a suitable pathway for applying HIFU to the liver, enabling a transthoracic, transpulmonary approach. The enlarged acoustic window could enhance the ablation speed for targets in the hepatic dome. The one-lung flooding technique may pave the way for more effective and less invasive treatments of liver tumors.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.7150/ijms.16411, Alternate LINK

Title: Flooded Lung Generates A Suitable Acoustic Pathway For Transthoracic Application Of High Intensity Focused Ultrasound In Liver

Subject: General Medicine

Journal: International Journal of Medical Sciences

Publisher: Ivyspring International Publisher

Authors: Thomas Günther Lesser, Carsten Boltze, Harald Schubert, Frank Wolfram

Published: 2016-01-01

Everything You Need To Know

What is High-Intensity Focused Ultrasound (HIFU) and what challenge does it face when treating liver tumors?

High-Intensity Focused Ultrasound (HIFU) is a non-invasive method used to treat liver malignancies. It works by targeting and destroying tumors without traditional surgery. However, tumors located in the liver dome, the uppermost region of the liver, are difficult to treat with HIFU because the adjacent air-filled lung acts as a barrier, blocking the ultrasound waves. Researchers are exploring 'one-lung flooding' to overcome this acoustic obstacle.

What is 'one-lung flooding' (OLF) and how does it enhance High-Intensity Focused Ultrasound (HIFU) treatment for liver tumors?

'One-lung flooding' (OLF) is a technique where one lung is filled with a saline solution to create a clear pathway for ultrasound waves. This allows for more precise and effective High-Intensity Focused Ultrasound (HIFU) ablation of liver tumors. By replacing air with fluid, the ultrasound waves can pass through the lung and target the liver tumor more effectively.

Can you describe how the 'one-lung flooding' technique and High-Intensity Focused Ultrasound (HIFU) were applied in the animal study?

The study involved using ultrasound-guided High-Intensity Focused Ultrasound (HIFU) to create thermal lesions in the livers of three pigs after inducing right-side lung flooding. The HIFU beam was directed transthoracically (through the chest wall) and transpulmonarily (through the lung) towards the liver, targeting different locations. The researchers carefully prepared the lung by filling it with a degassed and tempered isotonic saline solution. They then used a specialized HIFU applicator to deliver targeted ultrasound energy, monitored the process via diagnostic imaging and created thermal lesions. Finally autopsy examinations were performed.

What are the potential implications of using 'one-lung flooding' to improve High-Intensity Focused Ultrasound (HIFU) treatments for liver tumors?

The study's findings suggest that flooded lung provides a suitable pathway for applying High-Intensity Focused Ultrasound (HIFU) to the liver, enabling a transthoracic, transpulmonary approach. This enlarged acoustic window could potentially enhance the ablation speed for targets in the hepatic dome. The 'one-lung flooding' technique could lead to more effective and less invasive treatments for liver tumors in the future, especially for those difficult to reach with conventional methods. The success could minimize the need for invasive surgical procedures, thereby improving patient outcomes and recovery times.

What are the next steps in researching and implementing the 'one-lung flooding' technique alongside High-Intensity Focused Ultrasound (HIFU) for liver tumor treatment?

While the study showed promising results, the 'one-lung flooding' (OLF) technique requires careful execution to avoid complications. Future research needs to investigate the long-term effects of saline solution on the lung tissue and optimize the procedure for human application. Additionally, the optimal saline solution volume, the best imaging techniques for guiding High-Intensity Focused Ultrasound (HIFU) delivery, and patient selection criteria need to be further refined. Clinical trials are necessary to validate the safety and efficacy of OLF in treating human liver tumors.