iMRI Group

Clinical Applications

MRI (Magnetic Resonance Imaging) offers a multitude of advantages that have established it as a pivotal tool in modern medicine. Firstly, MRI is a non-invasive imaging technique, eliminating the need for harmful ionizing radiation present in other imaging methods. This makes it safe for patients of all ages, including children and pregnant women. Additionally, MRI provides exceptional soft tissue contrast, allowing for the clear visualization of various structures within the body, including the brain, spinal cord, organs, and joints. Its high-resolution images aid in the early detection and accurate diagnosis of a wide range of conditions. With its exceptional capabilities, MRI continues to play an integral role in advancing medical knowledge, guiding treatment decisions, and enhancing patient care.

Our group uses MRI for different types of interventions, such as:

Fig. 1: MR-guided microwave ablation of the liver. The radiologist places an applicator into the patient while monitoring the procedure using the MRI.

MR-guided Percutaneous Ablation

Fig. 1: Microwave ablation of liver tumor under MR-guidance. Real-time acquisition of three parallel slices allows precise navigation of the applicator.

MR-guided percutaneous ablations involve using real-time Magnetic Resonance Imaging (MRI) guidance to perform minimally invasive procedures that destroy or remove abnormal tissue. This technique allows for precise targeting of the tissue to be ablated, such as tumors or lesions, while minimizing damage to surrounding healthy tissue. During the procedure, the MRI scanner provides detailed images that help guide the placement of needles or probes into the target area (Fig. 1). Once positioned, energy, such as microwaves, radiofrequency or laser, is delivered through the needles or probes to heat or destroy the abnormal tissue. Progress of the procedure is monitored by MR-thermometry with so called temperature maps. These maps allow accurate temperature measurements and can be used to predict the destroyed volume ensuring good treatment outcomes (Fig. 2, 3).

Fig. 2: Assessment of tumor ablation progress using temperature maps at different points in time. Top: Growing region in temperature map shows spread of high temperatures. Middle: White outline shows predicted destroyed volume. Bottom: 3D visualization of ablation progress; red voxels are to be ablated, green voxels are fully destroyed. [1]
Fig. 3: GUI developed by Hille et al. used for the assessment of the treatment progress. [1]

MR-guided Pain Management

MR-guided pain therapy for piriformis pain syndrome utilizes real-time MRI to guide the precise placement of therapeutic interventions. This technique involves visualizing the affected area, such as the piriformis muscle and the impinged sciatic nerve, using MRI. The MRI images help identify the location and severity of the condition, enabling accurate diagnosis and treatment planning. Therapeutic interventions, such as targeted injections of medication, are then administered under MRI guidance. This approach improves the accuracy of treatment delivery, minimizes the risk of complications, and enhances pain relief for individuals with piriformis pain syndrome.

Fig. 4: Left image: Needle position in piriformis muscle (red arrow). Right image: Reduced volume of piriformis muscle after injection (red arrow). The left piriformis muscle is visibly larger (white arrow).

MR-guided Biopsy

MR-guided biopsy is a minimally invasive medical procedure that utilizes magnetic resonance imaging (MRI) technology to guide the precise sampling of tissue from within the body. This advanced technique is commonly employed in the diagnosis and assessment of various medical conditions, particularly in the detection of suspicious or hard-to-reach lesions, tumors, or abnormalities. MR-guided biopsies offer the advantage of including real-time visualization of the target area. This approach is especially valuable in oncology, as it aids in obtaining representative tissue samples for accurate diagnosis and treatment planning, ultimately contributing to better patient care and outcomes. Below you can see a typical case for a MR-guided biopsy on the liver where the needle is inserted into the tumor tissue (Fig. 5).

Fig. 5: Liver biopsy on Hepatocellular Carcinoma (HCC). The biopsy needle (black arrow) is inserted into the tumor (red arrow) under MR-guidance.

References:

[1] Hille et al. A novel tool for monitoring and assessing the outcome of thermal ablations of hepatic lesions. Current Directions in Biomedical Engineering 7 1 (2021).