Martina Callaghan

Keywords: Image acquisition: Quantification, Contrast mechanisms: Relaxometry, Neuro: Brain

This technical talk will focus on how mixed contrast “weighted” images can be combined with signal models to extract physical quantities that describe the relaxation behaviour of tissue – namely T1, T2 and T2*.  A number of approaches will be discussed including inversion recovery, MR fingerprinting and multi-parameter mapping.  Important practicalities that need to be considered to maximise the precision and accuracy of these measurements will be highlighted, including accounting for inhomogeneity in the transmit and main magnetic fields, as well as the validity of underlying model assumptions.

Akifumi Hagiwara

Keywords: Contrast mechanisms: Relaxometry, Neuro: Brain, Image acquisition: Quantification

Traditional MRI interpretations rely on contrasting tissue signals, not on absolute signal intensities. Quantification of tissue parameters such as relaxation rates and proton density, which provide an absolute scale, has been limited to research. Advances in rapid quantification are making clinical application viable. This lecture introduces these methods and the synthesis of contrast-weighted (synthetic MRI) images based on absolute values. It further examines the application of these techniques to brain diseases, with promising results in conditions like multiple sclerosis, brain metastases, Sturge-Weber syndrome, and pediatric disorders.