Slice selection in MRI

Slice selection in MRI is the selection of spins in a plane through the object. The principle behind slice selection is explained by the resonance equation. Slice selection is achieved by applying a one-dimensional, linear magnetic field gradient during the period that the RF pulse is applied.

1. What determines number of slices in MRI?
2. What determines slice thickness MRI?
3. What does slice thickness mean in a MRI?
4. What is slice thickness in MRI of brain?

What determines number of slices in MRI?

The number of slices obtainable can be calculated by dividing the repetition time TR by the time required for each slice. For example, if TR = 400 ms and TE = 50 ms, the theoretically possible number of slices is eight (in practice seven, since each slice requires slightly more than TE).

What determines slice thickness MRI?

The thickness of the slice is determined by a combination of two factors: (1) the strength, or steepness, of the gradient, and (2) the range of frequencies, or bandwidth, in the RF pulse.

What does slice thickness mean in a MRI?

Slice thickness is defined as the full width at half maximum (FWHM) signal intensity as shown in the diagram left.

What is slice thickness in MRI of brain?

Slice thickness ≤ 3.3 mm.