Good Correlation of Goutallier Rating of Supraspinatus Fatty Changes on Axial and Reformatted Parasagittal Computed Tomographic Images

Abstract

UNLABELLED Traumatic tendon tear of the rotator cuff occurs frequently and leads to fatty muscle infiltration. With regard to the outcome, fatty infiltration of the rotator cuff muscles constitutes a major negative predictive factor after rotator cuff surgery. In 1989, Goutallier et al established his classification system for assessment of fatty infiltration of the rotator cuff muscles. He used computed tomographic (CT) images in the axial plane. Today, the assessment of rotator cuff muscles on axial CT images has been widely replaced by assessment on parasagittal acquired magnetic resonance images. This change raised 2 important questions. First, there is a controversy whether the Goutallier classification can simply be adopted for magnetic resonance imaging. The second question is whether the muscle assessment in the axial plane is interchangeable with that in the parasagittal plane. We hypothesize that the assessment of fatty muscle infiltration is the same on reformatted parasagittal CT images as on axial CT images METHODS Three independent readers, 2 radiologists and one shoulder surgeon, rated fatty changes of the supraspinatus muscle on CT scans of 91 shoulders. Goutallier grades were assessed on axial and reformatted parasagittal CT images in 2 separate reading sessions. The paired t test was used to find differences between grading results on axial and reformatted parasagittal images. The Pearson correlation coefficient and weighted kappa statistics were used to quantify linear correlation, intrareader, and interreader agreement. RESULTS Mean (SD) Goutallier grading among all readers was 0.80 (1.16) (range, 0-4) on axial images and 0.89 (1.05) (range, 004) on parasagittal reconstructions. We detected a trend toward a slightly higher Goutallier grading on parasagittal reconstructions; however, this result was not significant (P = 0.07). The Pearson correlation coefficient was 0.702 (P < 0.001). Weighted kappa statistics indicated a moderately good to good intrareader (range of weighted kappa, 0.53-0.62) and interreader (weighted kappa, axial images, 0.55; reformatted parasagittal images, 0.65) agreement. CONCLUSION Grading of fatty infiltration of the supraspinatus muscle on parasagittal CT images is comparable with the standard Goutallier grading on axial images and is characterized by a moderately good to good intrareader and interreader agreement. Assessment of parasagittal images is characterized by a slightly higher interreader agreement and may therefore be the preferable modality.

Magnetic resonance imaging criteria for the assessment of the rotator cuff after repair: a systematic review

“…However, qualitative assessment of fatty infiltration of rotator cuff after surgery should be interpreted with caution due to the limited reliability of the current grading systems and several concerns still remain. A consensus on imaging modalities, planes and sequences need to be achieved [33, 94, 110, 115, 148, 160]. Although, MRI is the reference standard for the evaluation of the rotator cuff features, the grades of fatty infiltration are measured at one cross‐sectional image; thus, the section for evaluation may be placed at a relatively medial portion and may not represent the true degree of fatty infiltration of the whole muscle belly [115].…”

Imbalance in Axial-plane Rotator Cuff Fatty Infiltration in Posteriorly Worn Glenoids in Primary Glenohumeral Osteoarthritis: An MRI-based Study

“…Fatty infiltration of the rotator cuff was evaluated using T1 sagittal oblique sequences and the Goutallier classification, with scores ranging from 0 to 4 [8]. This system was originally created using CT to determine the degree of fatty infiltration on a single slice immediately medial to the spinoglenoid notch, Y-view [7,8,13]. MR images were reviewed in a similar fashion in order to assign Goutallier grades using the sagittal sequences.…”

Comparison of the Goutallier Classification of Fatty Infiltration for the Subscapularis With a Novel Modified Classification

“…12 However, because the classification is based on semiquantitative criteria, there have been discrepancies in interobserver reliability, with a broad range of k values reported (0.24-0.82). 15,18,26,31,34,38 Hence, some have suggested the need for new classification systems. Slabaugh et al 40 proposed a simplified Goutallier classification that merges grades 0 and 1 and grades 2 and 3.…”