Introduction Our aim was to evaluate the feasibility and to compare image quality and diagnostic
performance of 3-T and 7-T magnetic resonance imaging (MRI) for direct depiction of
finger pulley ruptures using anatomical preparation as a reference.
Material and Methods A total of 30 fingers from 10 human cadavers were examined at 3 T and 7 T before
and after being subjected to iatrogenic pulley ruptures. MRI protocols were comparable
in duration. Two experienced radiologists evaluated the MRIs and defined the location
and morphology of the finger pulley lesions. Image quality was graded according to
a 4-point Likert scale. The diagnostic performance was assessed with anatomical preparation
as the gold standard. Interobserver agreement was calculated using Cohen’s κ coefficients.
Results Sensitivity and specificity were comparable in 7 T versus 3 T for the detection of
A2, A3, and A4 pulley lesions: 100% versus 95% and 98% versus 100%, respectively.
In the assessment of A3 pulley lesions, sensitivity of 7-T was superior to 3-T MRI
(100% versus 83%), whereas specificity was lower (95% versus 100%). Image quality
assessed before and after iatrogenic rupture was comparable, 2.74 for 7 T and 2.61
for 3 T, reflecting adequate image quality on average, whereas visualization of the
A3 finger flexor pulley before rupture creation was significantly better for 7 T (p < 0.001). Interobserver variability was substantial at 7 T (κ = 0.90) and 3 T (κ = 0.80).
Conclusion MRI at 3 T and 7 T allows direct visualization of traumatic A2, A3, and A4 pulley
lesions with slightly higher agreement rates for 7 T. Hence high field MRI may be
a helpful approach for presurgical evaluation compared with indirect techniques such
as ultrasound that depends on bowstringing.
