Weightings
The most common weightings are:
Fig 1: T1 weighting, brain – click to zoom
T1 weighting is characterised by an increased signal from fatty tissue and a lower signal from fluid, giving a more structural view.
In particular, bony destruction or infiltration with loss of fatty tissue is highlighted.
Fig 2: T2 weighting, spine – click to zoom
T2 weighting produces images containing deep muscle tones and bright fluid, and can be very helpful in spinal views.
T2 weighting allows radiologists to move away from myelography to MRI in order to investigate cord or disc lesions.
Diffusion-weighted
Diffusion-weighted imaging uses the mobility of water molecules as a means of describing structure associated with impairment of molecular movement due to tissue characteristics.
Increasingly, it is commonly used for the diagnosis of ischaemic stroke [2].