Abstract
One of the main advantages of three-dimensional (3D) magnetic resonance imaging (MRI)
is the possibility of isotropic voxels and reconstructed planar cuts through the volumetric
data set in any orientation with multiplanar reformation software through real-time
evaluation. For example, reformats by the radiologist during reporting allows exploitation
of the full potential of isotropic 3D volumetric acquisition or through standardized
retrospective reformats of thicker predefined slices of an isotropic volumetric data
set by technologists. The main challenges for integrating 3D fast spin echo (FSE)
and turbo spin-echo (TSE) MRI in clinical practice are a long acquisition time and
some artifacts, whereas for integrating 3D gradient-recalled echo protocols, the main
challenges are lower signal-to-noise ratios (SNRs) and the inability to produce intermediate,
and T2-weighted contrast. The implementation of bidirectional parallel imaging acquisition
and random undersampling acceleration strategies of 3D TSE pulse sequences substantially
shortens the examination time with only minor SNR reductions. This article provides
an overview of general technical considerations of 3D FSE and TSE sequences in musculoskeletal
MRI. It also describes how these sequences achieve efficient data acquisition and
reviews the main advantages and challenges for their introduction to clinical practice.
Keywords
3D imaging - spin echo sequences - gradient-recalled echo sequences - musculoskeletal
imaging
