Abstract
Magnetic resonance imaging (MRI) is a powerful imaging modality for visualizing a
wide range of ankle disorders that affect ligaments, tendons, and articular cartilage.
Standard two-dimensional (2D) fast spin-echo (FSE) and turbo spin-echo (TSE) pulse
sequences offer high signal-to-noise and contrast-to-noise ratios, but slice thickness
limitations create partial volume effects. Modern three-dimensional (3D) FSE/TSE pulse
sequences with isotropic voxel dimensions can achieve higher spatial resolution and
similar contrast resolutions in ≤ 5 minutes of acquisition time. Advanced acceleration
schemes have reduced the blurring effects of 3D FSE/TSE pulse sequences by affording
shorter echo train lengths. The ability for thin-slice partitions and multiplanar
reformation capabilities eliminate relevant partial volume effects and render modern
3D FSE/TSE pulse sequences excellently suited for MRI visualization of several oblique
and curved structures around the ankle. Clinical efficiency gains can be achieved
by replacing two or three 2D FSE/TSE sequences within an ankle protocol with a single
isotropic 3D FSE/TSE pulse sequence. In this article, we review technical pulse sequence
properties for 3D MRI of the ankle, discuss practical considerations for clinical
implementation and achieving the highest image quality, compare diagnostic performance
metrics of 2D and 3D MRI for major ankle structures, and illustrate a broad spectrum
of ankle abnormalities.
Keywords
three-dimensional - magnetic resonance imaging - ankle - foot