Superior labral anterior-to-posterior lesions: comparison of external rotation and active supination CT arthrography with neutral CT arthrography

Comparison of conventional MR arthrography and 3D volumetric MR arthrography in detection of cartilage defects accompanying glenoid labrum pathologies

OBJECTIVES

In this study, we aimed to compare conventional and T1-weighted volumetric magnetic resonance arthrography (MRA) in the diagnosis and grading of glenoid cartilage defects that accompany labral pathologies.

MATERIALS AND METHODS

A total of 79 patients who were prediagnosed with labrum pathologies based on shoulder magnetic resonance imaging (MRI) had MRA and CTA between December 2021 and May 2022. CTA was regarded as reference standard. CTA images were examined by a radiologist experienced in musculoskeletal radiology, and MRA images were examined by two radiologists independently to determine presence, grade, and localization of any glenoid cartilage defect, if present. Sensitivity, specificity, and accuracy were calculated separately for conventional and T1-weighted volumetric MRA. In addition, at the last stage, two observers examined all MRAs together, and the presence of a cartilage defect was decided by consensus, and the overall sensitivity, specificity, and accuracy were calculated.

RESULTS

Cartilage defect was detected on CTAs of 48 (60.75%) cases of among 79 patients with labrum pathology. The sensitivity, specificity, and accuracy of conventional MRA for two examiners were 17-19%, 100-100%, and 49-51%, respectively, while those values were 67-65%, 92-97%, and 84-77%, respectively, for T1-weighted volumetric MRA. Inter-examiner agreement was excellent for diagnosis of cartilage defects on all MRAs. The overall sensitivity, specificity, and accuracy for detection of glenoid cartilage lesions by MRA were 69%, 97%, and 80%, respectively.

CONCLUSION

T1-weighted volumetric MRA seems to demonstrate cartilage defects accompanied with labrum pathologies accurately with high sensitivity, specificity, and excellent inter-examiner agreement.

Advantages of the Use of Axial Traction Magnetic Resonance Imaging (MRI) of the Shoulder in Patients with Suspected Rota-Tor Cuff Tears: An Exploratory Pilot Study

Magnetic Resonance Imaging (MRI) with axial traction is a tool for the assessment of musculoskeletal pathology. Previous reports have demonstrated a better distribution of intra-articular contrast material. No investigations were performed to evaluate glenohumeral joint axial traction MRI in patients with suspected rotator cuff tears. This study aims to assess the morphological changes and the potential advantage of glenohumeral joint axial traction MRI without intra-articular contrast administration in patients with suspected rotator cuff tears. Eleven patients with clinical suspicion of rotator cuff tears underwent a shoulder MRI scan with and without axial traction. PD weighted images with SPAIR fat saturation technique and T1 weighted images with TSE technique were acquired in the oblique coronal, oblique sagittal and axial planes. Axial traction allowed a significant widening of the subacromial space (11.1 ± 1.5 mm vs. 11.3 ± 1.8 mm; p = 0.001) and inferior glenohumeral space (8.6 ± 3.8 mm vs. 8.9 ± 2.8 mm; p = 0.029). With axial traction, there was a significant decrease in measurements of the acromial angle (8.3 ± 10.8° vs. 6.4 ± 9.8°; p < 0.001) and gleno-acromial angle (81 ± 12.8° vs. 80.7 ± 11.5°; p = 0.020). Our investigation demonstrates for the first time significant morphological changes in the shoulder of patients with suspected rotator cuff tears who underwent a glenohumeral joint axial traction MRI.

Efficacy of the Rotational Traction Method in the Assessment of Glenohumeral Cartilage Surface Area in Computed Tomography Arthrography

OBJECTIVE

We aimed to investigate the efficacy of the rotational traction method in expanding the joint space and enabling the assessment of an extended surface area.

METHODS

Sixty patients who underwent computed tomography arthrography were evaluated in the study: 30 with and 30 without the help of rotational traction. The subgroups consisted of patients with adhesive capsulitis, habitual luxation, or labral tears. Areas of obscured joint surface by coalescent cartilages were calculated using computer software, and those belonging to the traction and nontraction groups along with subgroups were compared statistically.

RESULTS

There was a significant difference between the traction and nontraction group regarding the contact surface area (P < 0.001 for both observers). In patients with adhesive capsulitis, the contact surface area was larger compared with the other subgroups (P = 0.002 for observer 1 and P = 0.002 for observer 2). In patients with habitual luxation, the contact surface area was smaller compared with the other subgroups (P = 0.002 for observer 1 and P = 0.001 for observer 2).

CONCLUSIONS

Expansion of joint distance is important for assessing the joint cartilage. The rotational traction method provides effective separation of the joint space. For this reason, rotational traction can be used effectively in patients in whom the joint cartilage is to be evaluated.

Axial traction magnetic resonance imaging (MRI) of the glenohumeral joint in healthy volunteers: initial experience

OBJECTIVE

Evaluate technical feasibility and potential applications of glenohumeral (GH) joint axial traction magnetic resonance imaging (MRI) in healthy volunteers.

MATERIALS AND METHODS

Eleven shoulders were imaged in neutral and with 4kg axial traction at 3T. Quantitative measurements were assessed.

RESULTS

Axial traction was well tolerated. There was statistically significant widening of the superior GH joint space (p=0.002) and acromial angle (p=0.017) with traction. Inter-rater agreement was high.

CONCLUSION

GH joint axial traction MRI is technically feasible and well tolerated in volunteers. Traction of the capsule, widening of the superior GH joint space and acromial angle were observed.

External rotation and active supination CT arthrography for the postoperative evaluation of type II superior labral anterior to posterior lesions

PURPOSE

To evaluate the effectiveness of external rotation and active supination CT arthrography in postoperative evaluation by comparing it with neutral CT arthrography and analyzing its agreement with postoperative clinical results after the repair of type II superior labral anterior to posterior (SLAP) lesions.

MATERIALS AND METHODS

A total of 25 patients who had undergone CT arthrography in neutral, external rotation and active supination position at least 1 year after the arthroscopic repair of SLAP lesions were enrolled. Two radiologists independently evaluated the status of the repaired SLAP lesions with neutral CT arthrography and then with external rotation and active supination CT arthrography.

RESULTS

Five patients had residual symptoms and positive findings upon SLAP-specific examinations. Agreements between the presence of symptoms and radiologic diagnoses based on neutral CT arthrography were insignificant for reader 1 (κ = 0.138, p = n.s.) and significant for reader 2 (κ = 0.328, p = 0.027). However, agreements were highly significant in the analysis following the evaluation of external rotation and active supination CT arthrography for both readers (κ = 0.694, p < 0.001 in reader 1; κ = 0.783, p < 0.001 in reader 2).

CONCLUSIONS

The presence of contrast-filled gaps between the labrum and glenoid on neutral CT arthrography after SLAP repair is frequent with satisfactory clinical outcomes. Gaps without additional widening upon external rotation and active supination CT arthrography may suggest postoperatively stable biceps anchors, so this new method could minimize the overdiagnosis of recurrent SLAP lesions. Additional gap widening on external rotation and active supination CT arthrography could be related to a true recurrent SLAP lesion and the symptoms of the patients.

LEVEL OF EVIDENCE

Case series, Level IV.

Comparison of image quality of shoulder CT arthrography conducted using 120 kVp and 140 kVp protocols

OBJECTIVE

To compare the image quality of shoulder CT arthrography performed using 120 kVp and 140 kVp protocols.

MATERIALS AND METHODS

Fifty-four CT examinations were prospectively included. CT scans were performed on each patient at 120 kVp and 140 kVp; other scanning parameters were kept constant. Image qualities were qualitatively and quantitatively compared with respect to noise, contrast, and diagnostic acceptability. Diagnostic acceptabilities were graded using a one to five scale as follows: 1, suboptimal; 2, below average; 3, acceptable; 4, above average; and 5, superior. Radiation doses were also compared.

RESULTS

Contrast was better at 120 kVp, but noise was greater. No significant differences were observed between the 120 kVp and 140 kVp protocols in terms of diagnostic acceptability, signal-to-noise ratio, or contrast-to-noise ratio. Lowering tube voltage from 140 kVp to 120 kVp reduced the radiation dose by 33%.

CONCLUSION

The use of 120 kVp during shoulder CT arthrography reduces radiation dose versus 140 kVp without significant loss of image quality.

MR arthrography of the shoulder: optimizing pulse sequence protocols for the evaluation of cartilage and labrum

OBJECTIVES

To compare axial T1weighted fat-saturated (T1w fs) and T1w non-fs sequences, and coronal T1w-fs and T2w-fs sequences, for evaluation of cartilage and labrum using CT arthrography (CTA) as the reference.

METHODS

Patients had MR arthrography (MRA) and CTA of the shoulder on the same day. Cartilage was assessed for superficial and full thickness focal and diffuse damage. Labral lesions were graded for Bankart variants and SLAP lesions. CTA images were read for the same features. The diagnostic performance of MRA including area under the curve (AUC) was evaluated against CTA.

RESULTS

When comparing axial sequences, the diagnostic performance for cartilage lesion detection on T1w non-fs was 61.9% (sensitivity) 93.6% (specificity) and 89.5% (accuracy) with AUC 0.782, while that for T1w fs was 61.9%, 94.0%, 89.8% and 0.783. For labral assessment, it was 89.1%, 93.0%, 91.4% and 0.919 for T1w non-fs, and 89.9%, 94.0%, 92.6% and 0.922 for T1w fs. Comparing coronal sequences, diagnostic performance for cartilage was 42.5%, 97.5%, 89.8% and 0.702 for T1w fs, and 38.4%, 98.7%, 90.2%, and 0.686 for T2w fs. For the labrum it was 85.1%, 87.5%, 86.2%, and 0.868 for T1w fs, and 75.7%, 97.5%, 80.8% and 0.816 for T2w fs.

CONCLUSIONS

Axial T1w fs and T1w non-fs sequences are comparable in their ability to diagnose cartilage and labral lesions. Coronal T1w fs sequence offers slightly higher sensitivity but slightly lower specificity than T2w fs sequence for diagnosis of cartilage and labral lesions.

Computed tomography and positive contrast computed tomographic arthrography of the canine shoulder: normal anatomy and effects of limb position on visibility of soft tissue structures

Soft tissue injuries of the shoulder are an important cause of forelimb lameness in dogs. The objectives of this canine cadaver study were to describe normal anatomy of shoulder soft tissue structures using computed tomography (CT) and computed tomographic arthrography (CTA) and to determine the effects of positioning on visualization of shoulder soft tissue structures. Thirteen forelimbs were removed from eight canine cadavers. Two forelimbs were used for contrast dose optimization. For the remaining 11 forelimbs, shoulder CT and CTA were performed using three defined joint angles (140°, 90°, and 70°). For three forelimbs, CT and CTA images were compared with frozen anatomic sections to describe normal anatomy. Ten forelimbs were used for analysis of positioning effects. Soft tissue structures evaluated were the joint capsule, cartilage, ligaments, tendons, and muscles. A visual assessment score was assigned to each structure using a consensus of two observers. The range and mode of scores were calculated and compared for each modality and limb position. The shoulder joint capsule and medial and lateral glenohumeral ligaments were completely visible with CTA. All tendons and muscles were visualized in all the examinations except for the teres minor muscle tendon and the coracobrachialis muscle, which were not visible on all scans. Positioning the limb in an extended position significantly improved visualization of most soft tissue shoulder structures. Shoulder cartilage was best seen with CTA and with neutral or flexed positioning of the shoulder. Findings indicated that both CT and CTA are feasible imaging techniques for visualization of soft tissue structures of the canine shoulder.

Direct MR arthrography of the shoulder under axial traction: feasibility study to evaluate the superior labrum-biceps tendon complex and articular cartilage

PURPOSE

To assess the value of adding axial traction to direct MR arthrography of the shoulder, in terms of subacromial and glenohumeral joint space widths, and coverage of the superior labrum-biceps tendon complex and articular cartilage by contrast material.

MATERIALS AND METHODS

Twenty-one patients investigated by direct MR arthrography of the shoulder were prospectively included. Studies were performed with a 3 Tesla (T) unit and included a three-dimensional isotropic fat-suppressed T1-weighted gradient-recalled echo sequence, without and with axial traction (4 kg). Two radiologists independently measured the width of the subacromial, superior, and inferior glenohumeral joint spaces. They subsequently rated the amount of contrast material around the superior labrum-biceps tendon complex and between glenohumeral cartilage surfaces, using a three-point scale: 0 = no, 1 = partial, 2 = full.

RESULTS

Under traction, the subacromial (Δ = 2.0 mm, P = 0.0003), superior (Δ = 0.7 mm, P = 0.0001) and inferior (Δ = 1.4 mm, P = 0.0006) glenohumeral joint space widths were all significantly increased, and both readers noted significantly more contrast material around the superior labrum-biceps tendon complex (P = 0.014), and between the superior (P = 0.001) and inferior (P = 0.025) glenohumeral cartilage surfaces.

CONCLUSION

Direct MR arthrography of the shoulder under axial traction increases subacromial and glenohumeral joint space widths, and prompts better coverage of the superior labrum-biceps tendon complex and articular cartilage by contrast material.