PREFUL MRI Method Enables New Insights into Lung Function

A team led by BREATH scientists Prof. Dr. Jens Vogel-Claussen and Dr. Andreas Voskrebenzev has developed an innovative MRI method that provides a regional view of lung function without radiation exposure or breath holds. The researchers have now shared their findings in the ‘Journal of Visualized Experiments’.

Detecting and assessing lung diseases is a significant medical challenge. While conventional computed tomography (CT) provides high-resolution imaging of lung structure, it reveals little about lung function and exposes patients to radiation. Lung function tests are well-established but only provide values for the entire lung, indicating whether the lung is diseased but not pinpointing where exactly. An alternative is magnetic resonance imaging (MRI), which operates without radiation. However, the high air content in the lungs makes MRI challenging, as only hydrogen-rich tissue is clearly visible in MRI images. Additionally, traditional lung MRI requires patients to hold their breath multiple times.

Journal Publishes Article and Detailed Video Guide

To make lung MRI more patient-friendly and widely accessible, researchers led by Prof. Dr. Jens Vogel-Claussen, Chief Senior Physician at the Institute for Diagnostic and Interventional Radiology at Hannover Medical School (MHH) and part of the German Center for Lung Research at the Hannover site (DZL, BREATH location), developed the so-called PREFUL method. This imaging technique enables conventional MRI equipment to display lung ventilation and blood flow at high temporal resolution without contrast agents, specially developed MRI software (sequences), or breath holds. To maximize patient benefit from PREFUL MRI, the researchers have now published the complete examination procedure with all necessary calculations for image evaluation in the ‘Journal of Visualized Experiments’. Uniquely, the electronic journal offers a detailed video recording alongside the article for comprehensive guidance.

No Additional Equipment or Staff Required

PREFUL stands for "phase-resolved functional lung." This MRI method captures signal changes in the lungs across the entire breathing and cardiac cycle. It not only measures how lung tissue density changes with inhalation and exhalation but also tracks variations as the heart pumps blood through the imaging plane. “This now allows us to quantify regional lung function in early stages of lung disease, improve therapy monitoring, and even predict disease progression, such as after lung transplantation,” explains Prof. Vogel-Claussen.

“The PREFUL MRI has many advantages,” says MRI physicist Dr. Andreas Voskrebenzev, who was instrumental in developing the technique. “It provides spatially resolved functional information to locate exactly where in the lung the problem is, making the examination more comfortable for patients and less demanding. It requires only standard MRI equipment, no additional technical apparatus, and no extra medical staff.” This experimentally well-established method is especially beneficial for radiology practices and clinics interested in exploratory imaging markers. These lung function measurements are not yet clinically established but are used in research, making them suitable for monitoring sensitive patient groups, such as children with chronic lung diseases or patients with renal insufficiency.

PREFUL MRI Validated in Numerous Studies

During the examination, approximately three to five images per second are generated, each corresponding to a specific breathing and cardiac phase. “We can rearrange the images after the MRI examination to group multiple images from a particular breathing and heart phase, achieving higher temporal resolution and gaining more information,” explains Dr. Voskrebenzev. The images can then be converted into biomarkers, providing concrete values for lung blood flow in milliliters per minute, for instance. The researchers have tested the method across multiple studies with different disease profiles and age groups. For example, they demonstrated that breathing function improved significantly in COPD patients following inhalation therapy, as directly visualized in the lung, according to the BREATH scientist.

Better Prediction of Post-Transplant Complications

The PREFUL MRI method has also proven useful for patients with cystic fibrosis, pulmonary hypertension, and COVID-19, helping to assess these diseases and monitor treatment progress post-therapy. Additionally, PREFUL MRI can better predict chronic complications following lung transplants. With their publication, the researchers provide a kind of handbook, including precise instructions, potential pitfalls, and troubleshooting tips for their PREFUL method. Their goal is to make this technique accessible to all interested radiologists and promote wider adoption of PREFUL MRI.

Within the DZL, this methodology also opens new transdisciplinary collaboration opportunities and supports scientists and physicians both in clinical applications and fundamental research on disease causes.
 

Text: Kirsten Pötzke MHH, BREATH/AB

Photos: Dr. Andreas Voskrebenzev/MHH

Developed the PREFUL method for regional lung imaging in MRI: BREATH scientists Dr. Andreas Voskrebenzev und Prof. Dr. Jens Vogel-Claussen (left to right)

Three exemplary PREFUL images of a cystic fibrosis patient display information on lung perfusion (blood flow) and ventilation. Both in the individual maps (top and middle, dark tones) and in the combined so-called V/Q map (bottom), it is evident that many areas with impaired lung function (red, blue, purple) are present, deviating from normal lung function (green).