Main applications of perfusion MRI
Thanks to the possibility it opens up of exploring microvascularisation, perfusion MRI is of interest in:
- vascular diseases: ischemic stroke (search for penumbra / mismatch corresponding to viable brain tissue), study of vasospasm in subarachnoid hemorrhage
- tumoral diseases: perfusion MRI is used to evaluate neoangiogenesis and tumoral vascularisation, with an impact on the diagnosis or aftercare treatment of certain nervous tumors (high grade glioma, lymphoma meningioma, pilocytic astrocytoma, metastasis…) (figure 12.6)
- infectious or inflammatory diseases, one of whose physiopathological characteristics is hypervascularisation, can be explored in perfusion MRI.
Perfusion MRI techniques, in first pass and by spin labeling, demand high temporal resolution, a good signal-to-noise ratio with the highest possible spatial resolution.
They benefit from parallel acquisition methods, stronger static fields (3 T, or even 7 T) and sequence optimization (Echo planar, PRESTO: PRinciples of Echo-Shifting with a Train of Observations, steady-state Gradient Echo with reinforced T2, ultrafast spin echo…). Improvements in these techniques, are leading to the development of their clinical applications.