TY - JOUR

T1 - UTE T2* mapping of tendinopathic patellar tendons

T2 - an MRI reproducibility study

AU - Agergaard, Anne Sofie

AU - Malmgaard-Clausen, Nikolaj M.

AU - Svensson, Rene B.

AU - Nybing, Janus D.

AU - Boesen, Mikael

AU - Kjaer, Michael

AU - Magnusson, S. Peter

AU - Hansen, Philip

N1 - Publisher Copyright: © The Foundation Acta Radiologica 2020.

PY - 2021

Y1 - 2021

N2 - Background: There is currently a lack of imaging modalities that can be used as a sensitive measure in tendinopathy. Recent findings suggest the applicability of ultra-short echo time (UTE) magnetic resonance imaging (MRI) T2* mapping in tendons, but the reproducibility remains unknown. Purpose: To evaluate test–retest reproducibility of UTE MRI T2* mapping of tendinopathic patellar tendons and to evaluate the intra- and inter-observer reproducibility of the measurement. Material and Methods: Fifteen patients with chronic patellar tendinopathy were evaluated with UTE MRI twice in a 3.0-T scanner on the same day. Manual segmentation of the patellar tendon was performed by two blinded investigators and automated T2*map reconstruction was performed in custom-made software. Results: There was a significant and numerically small difference in test–retest T2* values (T2*meandiff = 0.06 ± 0.07 ms ≈ 3.7%; P = 0.006) with an ICC = 0.91 (95% confidence interval [CI] 0.58–0.98; typical error of 3.0%). The intra- and inter-observer reproducibility showed no significant bias (P = 0.493 and P = 0.052), and generally substantial reproducibility was demonstrated for T2* (intra-observer ICC = 0.99; 95% CI 0.98–1.00 and inter-observer ICC = 0.99; 95% CI 0.96–1.00, and typical error 1.3% and 1.3%, respectively). Conclusion: These data demonstrate a small bias between repeated measurements for UTE T2*, but with a very low associated mean difference (3.7%) between the two tests. The high ICC values and low typical error % demonstrate reproducibility of repeated T2*-mapping sessions. Further, the method showed substantial intra- and inter-observer reproducibility for T2* values proving feasibility for use of UTE T2* mapping in research and clinical practice.

AB - Background: There is currently a lack of imaging modalities that can be used as a sensitive measure in tendinopathy. Recent findings suggest the applicability of ultra-short echo time (UTE) magnetic resonance imaging (MRI) T2* mapping in tendons, but the reproducibility remains unknown. Purpose: To evaluate test–retest reproducibility of UTE MRI T2* mapping of tendinopathic patellar tendons and to evaluate the intra- and inter-observer reproducibility of the measurement. Material and Methods: Fifteen patients with chronic patellar tendinopathy were evaluated with UTE MRI twice in a 3.0-T scanner on the same day. Manual segmentation of the patellar tendon was performed by two blinded investigators and automated T2*map reconstruction was performed in custom-made software. Results: There was a significant and numerically small difference in test–retest T2* values (T2*meandiff = 0.06 ± 0.07 ms ≈ 3.7%; P = 0.006) with an ICC = 0.91 (95% confidence interval [CI] 0.58–0.98; typical error of 3.0%). The intra- and inter-observer reproducibility showed no significant bias (P = 0.493 and P = 0.052), and generally substantial reproducibility was demonstrated for T2* (intra-observer ICC = 0.99; 95% CI 0.98–1.00 and inter-observer ICC = 0.99; 95% CI 0.96–1.00, and typical error 1.3% and 1.3%, respectively). Conclusion: These data demonstrate a small bias between repeated measurements for UTE T2*, but with a very low associated mean difference (3.7%) between the two tests. The high ICC values and low typical error % demonstrate reproducibility of repeated T2*-mapping sessions. Further, the method showed substantial intra- and inter-observer reproducibility for T2* values proving feasibility for use of UTE T2* mapping in research and clinical practice.

KW - Patellar tendon

KW - reproducibility

KW - T2 mapping

KW - tendinopathy

KW - ultra-short echo time imaging

U2 - 10.1177/0284185120918807

DO - 10.1177/0284185120918807

M3 - Journal article

C2 - 32340475

AN - SCOPUS:85084853803

VL - 62

SP - 215

EP - 224

JO - Acta Radiologica - Series Diagnosis

JF - Acta Radiologica - Series Diagnosis

SN - 0365-5954

IS - 2

ER -