Advanced tissue characterization
Elastography: Magnetic Resonance Elastography (MRE) is a non-invasive technique that remotely quantifies the mechanical properties of organs and the heterogeneous structure of tumors. To obtain such information, a continuous periodic vibration in the organ of interest is induced by means of an external transducer placed in contact with the patient. Although, to date, MRI is the gold standard for Glioblastoma Multiforme (GBM) diagnosis and treatment follow-up, it is not specific to tumor infiltration processes and cannot properly discriminate treatment response and immune activities from tumor growth, leading to phenomena like pseudo-response and pseudo-relapse. qbig efforts currently focus on defining and optimizing an MRE protocol for GBM patients that provides meaningful and robust data while preserving patient’s comfort. Once this initial step is validated, the diagnostic performance of MRE in discriminating between tumors’ progression or response to treatments thanks to quantified mechanical information will be assessed.
Arterial Spin Labeling: Arterial Spin Labeling (ASL) is a non-invasive MRI technique to measure cerebral blood flow. In ASL, the spins of inflowing arterial blood are labeled proximal to the imaging slab and are used as intrinsic contrast agent. Due its quantitative nature, ASL is of particular interest in assessing perfusion. The technical developments over the last years promoted the application of ASL in clinical settings. As there is no need for additional application of gadolinium-based tracer, ASL can be applied repetitively and it is suitable for patients with contraindications to contrast agent application. Besides the quantification of the cerebral blood flow, ASL can further provide additional information about the hemodynamics by measuring the bolus arrival time. In the ongoing Swiss Atrial Fibrilation Cohort Study (Swiss AF), we assess putative brain perfusion changes with an optimized ASL protocol based on 3D GRASE.