Potential and limitations of magnetic resonance imaging for real-time monitoring of interstitial laser phototherapy.

Acad Radiol

Division of Health Physics, Istituto Nazionale per lo Studio e la Cura del Tumori, Milano, Italy.

Published: September 1995

Rationale And Objectives: Magnetic resonance (MR) imaging has been suggested as a method to monitor interstitial laser phototherapy (ILP) in deep tissues. Unfortunately, a reliable relation between temperature and MR parameters has not yet been demonstrated. In this study, we examined whether such a relation exists and whether MR imaging can measure absolute temperature or temperature changes.

Methods: We evaluated, in the range of 21 degrees C to 80 degrees C, the temperature dependence of the MR imaging signal and T1 in samples of liver, water, CuSO4, and oil. Spin-echo and fast low-angle shot (FLASH) sequences were used.

Results: The MR imaging signal of liver, CuSO4, and water continuously decreased when the temperature was increased from 21 degrees C to 80 degrees C. By contrast, the MR imaging signal of the oil increased with increasing temperature up to 40-50 degrees C and then decreased at higher temperatures. We observed a reliable linear relation only between T1 and temperature in a range' of 30-60 degrees C for oil and CuSO4.

Conclusion: MR imaging has the potential to measure thermal variations with an uncertainty of approximately +/- 10 degrees C. However, the use of MR imaging to monitor the real-time thermal effect induced in biologic tissues during laser irradiation requires further investigation before it can be applied clinically.

Download full-text PDF

Source
http://dx.doi.org/10.1016/s1076-6332(05)80482-9DOI Listing

Publication Analysis

Top Keywords

imaging signal
12
magnetic resonance
8
imaging
8
resonance imaging
8
interstitial laser
8
laser phototherapy
8
relation temperature
8
degrees degrees
8
temperature
7
degrees
7

Similar Publications

A NIRS-Based Technique for Monitoring Brain Tissue Oxygenation in Stroke Patients.

Sensors (Basel)

December 2024

Division of Neurological Rehabilitiation, Instituto Nacional de Rehabilitacion Luis Guillermo Ibarra Ibarra, Mexico City 14389, Mexico.

Stroke is a global health issue caused by reduced blood flow to the brain, which leads to severe motor disabilities. Measuring oxygen levels in the brain tissue is crucial for understanding the severity and evolution of stroke. While CT or fMRI scans are preferred for confirming a stroke due to their high sensitivity, Near-Infrared Spectroscopy (NIRS)-based systems could be an alternative for monitoring stroke evolution.

View Article and Find Full Text PDF

Optimized Synthetic Correlated Diffusion Imaging for Improving Breast Cancer Tumor Delineation.

Sensors (Basel)

December 2024

Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.

Breast cancer is a significant cause of death from cancer in women globally, highlighting the need for improved diagnostic imaging to enhance patient outcomes. Accurate tumor identification is essential for diagnosis, treatment, and monitoring, emphasizing the importance of advanced imaging technologies that provide detailed views of tumor characteristics and disease. Recently, a new imaging modality named synthetic correlated diffusion imaging (CDI) has been showing promise for enhanced prostate cancer delineation when compared to existing MRI imaging modalities.

View Article and Find Full Text PDF

We demonstrate high-resolution single-pixel imaging (SPI) in the visible and near-infrared wavelength ranges using an SPI framework that incorporates a novel, dedicated sampling scheme and a reconstruction algorithm optimized for the rapid imaging of highly sparse scenes at the native digital micromirror device (DMD) resolution of 1024 × 768. The reconstruction algorithm consists of two stages. In the first stage, the vector of SPI measurements is multiplied by the generalized inverse of the measurement matrix.

View Article and Find Full Text PDF

Advancements in Raman light sheet microscopy have provided a powerful, non-invasive, marker-free method for imaging complex 3D biological structures, such as cell cultures and spheroids. By combining 3D tomograms made by Rayleigh scattering, Raman scattering, and fluorescence detection, this modality captures complementary spatial and molecular data, critical for biomedical research, histology, and drug discovery. Despite its capabilities, Raman light sheet microscopy faces inherent limitations, including low signal intensity, high noise levels, and restricted spatial resolution, which impede the visualization of fine subcellular structures.

View Article and Find Full Text PDF

The precise localization of epileptic foci with the help of EEG or iEEG signals is still a clinical challenge with current methodology, especially if the foci are not close to individual electrodes. On the research side, dipole reconstruction for focus localization is a topic of recent and current developments. Relatively low numbers of recording electrodes cause ill-posed and ill-conditioned problems in the inversion of lead-field matrices to calculate the focus location.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!