Comparing the MRI-based Goutallier Classification to an experimental quantitative MR spectroscopic fat measurement of the supraspinatus muscle

Abstract

BackgroundThe Goutallier Classification is a semi quantitative classification system to determine the amount of fatty degeneration in rotator cuff muscles. Although initially proposed for axial computer tomography scans it is currently applied to magnet-resonance-imaging-scans. The role for its clinical use is controversial, as the reliability of the classification has been shown to be inconsistent. The purpose of this study was to compare the semi quantitative MRI-based Goutallier Classification applied by 5 different raters to experimental MR spectroscopic quantitative fat measurement in order to determine the correlation between this classification system and the true extent of fatty degeneration shown by spectroscopy.MethodsMRI-scans of 42 patients with rotator cuff tears were examined by 5 shoulder surgeons and were graduated according to the MRI-based Goutallier Classification proposed by Fuchs et al. Additionally the fat/water ratio was measured with MR spectroscopy using the experimental SPLASH technique. The semi quantitative grading according to the Goutallier Classification was statistically correlated with the quantitative measured fat/water ratio using Spearman’s rank correlation.ResultsStatistical analysis of the data revealed only fair correlation of the Goutallier Classification system and the quantitative fat/water ratio with R = 0.35 (p < 0.05). By dichotomizing the scale the correlation was 0.72. The interobserver and intraobserver reliabilities were substantial with R = 0.62 and R = 0.74 (p < 0.01).ConclusionThe correlation between the semi quantitative MRI based Goutallier Classification system and MR spectroscopic fat measurement is weak. As an adequate estimation of fatty degeneration based on standard MRI may not be possible, quantitative methods need to be considered in order to increase diagnostic safety and thus provide patients with ideal care in regard to the amount of fatty degeneration. Spectroscopic MR measurement may increase the accuracy of the Goutallier classification and thus improve the prediction of clinical results after rotator cuff repair. However, these techniques are currently only available in an experimental setting.

A pilot study: Can shear wave elastography predict fatty infiltration of the supraspinatus muscle?

“…However, further comparison is problematic. The SPLASH technique only has fair correlation with traditional MR Goutallier scoring 11 and the range of SWS for each Goutallier grading is not described.…”

“…Although regarded as the gold standard for investigation and classification of the degree of fatty infiltration, questions as to the validity and reliability of the MRI technique of Goutallier classification 29 have led some to search for alternative methods of assessment 10,11 . 2D‐SWE has the ability to quantitatively characterise the biomechanical properties of soft tissue.…”

“…With the development of, and preference to use, MRI for assessment of the rotator cuff, Fuchs et al 9 adapted the Goutallier scale and MRI is the current gold standard for evaluation of fatty infiltration (Figure 1). 10,11 …”

“…However, ultrasound (US) and MRI are considered subjective or semi‐quantitative assessments and authors such as Gilbert et al, 11 call for the establishment of more quantitative data to improve reproducibility of classifications. The evolving technology of 2D‐SWE allows for quantitative measurement of the stiffness of biological soft tissues.…”

Operative Refixation bei proximalem Hamstringabriss: Ist der OP-Zeitpunkt relevant für das funktionelle Outcome?

“…Zum einen ist dies bei länger zurückliegendem Trauma durch eine Narbenbildung-bedingte höhere operative Herausforderung mit entsprechendem Aufwand bedingt. Zudem kann es bei länger anhaltendem Funktionsverlust der Muskulatur zu einer strukturellen Metaplasie bis hin zu einer komplet-ten fettigen Infiltration kommen [16], die ab einem gewissen Maß das Erlangen einer funktionellen Verbesserung durch Refixation ohnehin fraglich macht (▶ Abb. 1).…”