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Into the Future with Metrology - The Challenges of Medical Technology

Diagnostics and Therapy

When the MRI scanner does the analyses on its own

Tissue-specific relaxation time
In MRI, the tissue-specific relaxation time T1 serves as a quantitative marker. T1 describes the temporal behavior of nuclear spins after excitation with an alternating magnetic field. Figure: T1 maps of the heart of a healthy test person and a patient.

Most MR images provide qualitative information. They require the well-trained eye of a radiologist who can recognize differences in contrast and infer pathologically altered tissue characteristics. In the case of quantitative imaging, the device determines biophysical parameters (e.g. the speed of blood flow) itself, and these parameters can be used directly to objectively determine diseases. This has improved the comparability of test results and has allowed data to be consolidated for multi-center studies. Quantitative MRI is a worldwide trend in radiology; in the past few years, major international societies have launched initiatives to support this development. Quantitative MRI also plays a role in the NAKO Health Study – Germany's largest cohort study – in which 200,000 people between the ages of 20 and 69 are interviewed on their living conditions and medical history and undergo medical examinations. In close cooperation with hospitals and MRI equipment manufacturers – at the interface between industry and clinical applications – PTB is working on making quantitative MRI imaging procedures even more accurate and reliable. Examples of this are the development of faster scans for 4D Flow MRI with which the quantitative blood flow velocity during the cardiac cycle can be determined, or the determination of the tissue-specific relaxation time T1 to diagnose heart muscle diseases. The problem of organ movement due to respiration has also been solved. A patient's respiratory movements are recorded very accurately, and motion artifacts in the MR images are corrected. This helps, for example, to precisely and quantitatively assess liver tumors, while a patient can breathe freely during the examination. In the future, quantitative MRI will become increasingly important for MR-guided radiation therapy, which is still quite a new and rapidly growing field.

  

Department involved

Opens internal link in current window8.1 Biomedical Magnetic Resonance