UTE imaging techniques, including quantitative measurements such as T2* and off resonance saturation ratios, are increasingly being investigated in patients with musculoskeletal diseases which involve tissues that are difficult to assess with conventional MRI. Diseases that have been assessed using UTE imaging include Achilles tendinopathy, articular cartilage and meniscal injury in the knee and degenerative disc disease in the spine. UTE imaging estimates of cortical bone pore water are being validated with the aim of improving fracture risk assessment.
Highlights
Quantitative UTE imaging techniques are increasingly used
UTE imaging has been investigated in the assessment of patients with Achilles tendinopathy
UTE has been used to image deep articular cartilage in the knee
Clinically feasible sequences for estimating pore water in bone are being validated
Articular cartilage: The osteochondral junction tissues have been postulated to be important in the development of osteoarthritis, however their short T2 limits visualization with conventional MRI. UTE imaging, particularly with long T2 suppression, can show linear high signal, which has been attributed to the deep cartilage. A study of patients undergoing anterior cruciate ligament reconstruction reported significant differences in the UTE-T2* of the deep cartilage compared to control subjects even when the cartilage was arthroscopically normal. T2* differences with controls had reduced 2 years after ACL reconstruction.
Cortical bone: Clinically feasible UTE imaging methods have been developed which allow the assessment of bound water and pore water within cortical bone, which are of interest as potential predictors of fracture risk. They have been compared with peripheral quantitative CT cortical volumetric bone mineral density and age.
Spine: The cartilaginous endplate may be important in degenerative disc disease. A characteristic appearance on UTE images with longer TE subtraction has been attributed to the cartilaginous endplate. Changes at the cartilaginous endplate visualised by UTE imaging have been associated with degenerative changes in disc.
Meniscus: UTE T2* of the meniscus has been been reported to be higher in patients with anterior cruciate ligament tear than asymptomatic controls even without a meniscal tear.
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