Evaluation of shoulder pathology: three-dimensional enhanced T1 high-resolution isotropic volume excitation MR vs two-dimensional fast spin echo T2 fat saturation MR

Single-Plane 3-Dimensional Isotropic Spin-Echo Magnetic Resonance Imaging Reconstructions of Shoulder Exhibit Superior Correlation to Surgical Findings Than 2-Dimensional Dixon Multiplanar Magnetic Resonance Imaging

OBJECTIVE

The aim of the study is to evaluate concordance of multiplanar 2-dimensional magnetic resonance imaging (2D-MRI) versus 3D isotropic MRI for rotator cuff and labral tears with the reference standard of arthroscopic surgical findings.

METHODS

It was an institutional review board-approved retrospective single-center study of consecutive preoperative patients with isotropic 3D-MRI on 3-Tesla scanners, multiplanar 2D-MRI, and shoulder arthroscopy. Scapular plane-oriented contiguous multiplanar reconstructions of 3D-images were evaluated by 2 experienced fellowship-trained musculoskeletal radiologists. Variables included the following: labral tear presence and rotator-cuff tear Ellman grade, thickness, and width. Sensitivities (Sen) and specificities (Spe) were calculated for binary variables. Mean squared errors (MSE) were calculated for ordinal variables. Lower MSE indicated higher concordance.

RESULTS

Seventy-two patients (43 female) with a mean age of 50.75 ± 9.76 years were evaluated. For infraspinatus-tear presence, 3D-MRI showed higher sensitivity (0.96) and specificity (0.68) than 2D-MRI (Sen = 0.85, Spe = 0.32) ( Psen = 0.005, Pspe = 0.002). For subscapularis-tear presence, 3D-MRI showed higher sensitivity (0.94) and specificity (0.73) compared with 2D-MRI (Sen = 0.83, Spe = 0.56) ( Psen = 0.02, Pspe = 0.04). For supraspinatus-tear presence, there was no significant difference between 3D-MRI (Sen =0.96, Spe = 0.67) compared with 2D-MRI (Sen = 0.98, Spe = 0.83) ( Psen = 0.43, Pspe = 0.63). For infraspinatus-tear thickness, 3D-MRI showed lower MSE (0.35) compared with 2D-MRI MSE (0.82) ( P = 0.01). For subscapularis-tear thickness, 3D-MRI had lower MSE (0.31) compared with 2D-MRI MSE (0.51) ( P = 0.007). However, no difference noted for supraspinatus-tear thickness when comparing 3D-MRI MSE (0.39) and 2D-MRI MSE (0.51) ( P = 0.49). For labral-tear presence, 3D-MRI had a lower MSE (0.20) compared with 2D-MRI MSE (0.57) ( P < 0.001).

CONCLUSIONS

Three-dimensional MRI of the shoulder is time efficient with a shorter acquisition time and exhibits comparable with superior correlation to surgical findings than 2D-MRI for detection of labral tears and some rotator cuff tears. Three-dimensional MRI may be used in place of traditional 2D-MRI in detection of soft-tissue shoulder injury in centers equipped to do so.

Image Quality and Diagnostic Performance of Accelerated Shoulder MRI With Deep Learning-Based Reconstruction

Background: Shoulder MRI using standard multiplanar sequences requires long scan times. Accelerated sequences have tradeoffs in noise and resolution. Deep learning-based reconstruction (DLR) may allow reduced scan time with preserved image quality. Objectives: To compare standard shoulder MRI sequences and accelerated sequences without and with DLR in terms of image quality and diagnostic performance. Methods: This retrospective study included 105 patients (45 men, 60 women; mean age 57.6±10.9 years) who underwent a total of 110 3-T shoulder MRI examinations. Examinations included standard sequences (scan time, 9 minutes 23 seconds) and accelerated sequences (3 minutes 5 seconds; 67% reduction), both including fast spin echo sequences in three planes. Standard sequences were reconstructed using the conventional pipeline; accelerated sequences were reconstructed using both conventional pipeline and a commercially available DLR pipeline. Two radiologists independently assessed three image sets (standard, accelerated without DLR, accelerated with DLR) for subjective image quality and artifacts using 4-point scales (4=highest quality), and identified pathologies of subscapularis tendon, supraspinatus-infraspinatus tendon, biceps brachii long head tendon, and glenoid labrum. Interobserver and inter-image set agreement for the evaluated pathologies was assessed using weighted kappa statistics. In 27 patients who underwent arthroscopy, diagnostic performance was calculated using arthroscopic findings as reference. Results: Mean subjective image quality for readers 1 and 2 was 10.6±1.2 and 10.5±1.4 for standard, 8.1±1.3 and 7.2±1.1 for accelerated without DLR, and 10.7±1.2 and 10.5±1.6 for accelerated with DLR. Mean artifact score for readers 1 and 2 was 9.3±1.2 and 10.0±1.0 for standard, 7.3±1.3 and 9.1±0.8 for accelerated without DLR, and 9.4±1.2 and 9.8±0.8 for accelerated with DLR. Interobserver agreement ranged from kappa=0.813-0.951 except for accelerated without DLR for SST-IST (κ=0.673). Inter-image set agreement ranged from kappa=0.809-0.957 except for reader 1 for SST-IST (κ=0.663-0.700). Accuracy, sensitivity, and specificity for tears of the four structures was not different (p>.05) among image sets. Conclusions: Accelerated sequences with DLR provide 67% scan time reduction with similar subjective image quality, artifacts, and diagnostic performance as standard sequences. Clinical impact: Accelerated sequences with DLR may provide an alternative to standard sequences for clinical shoulder MRI.

Detecting Rotator Cuff Tears: A Network Meta-analysis of 144 Diagnostic Studies

BACKGROUND

Many imaging techniques have been developed for the detection of rotator cuff tears (RCTs). Despite numerous quantitative diagnostic studies, their relative accuracy remains inconclusive.

PURPOSE

To determine which of 3 commonly used imaging modalities is optimal for the diagnosis of RCTs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Studies evaluating the performance of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA), and ultrasound (US) used in the detection of RCTs were retrieved from the PubMed/MEDLINE and Embase databases. Diagnostic data were extracted from articles that met the inclusion/exclusion criteria. A network meta-analysis was performed using an arm-based model to pool the absolute sensitivity and specificity, relative sensitivity and specificity, and diagnostic odds ratio as well as the superiority index for ranking the probability of these techniques.

RESULTS

A total of 144 studies involving 14,059 patients (14,212 shoulders) were included in this network meta-analysis. For the detection of full-thickness (FT) tears, partial-thickness (PT) tears, or any tear, MRA had the highest sensitivity, specificity, and superiority index. For the detection of any tear, MRI had better performance than US (sensitivity: 0.84 vs 0.81, specificity: 0.86 vs 0.82, and superiority index: 0.98 vs 0.22, respectively). With regard to FT tears, MRI had a higher sensitivity and superiority index than US (0.91 vs 0.87 and 0.67 vs 0.28, respectively) and a similar specificity (0.88 vs 0.88, respectively). The results for PT tears were similar to the detection of FT tears. A sensitivity analysis was performed by removing studies involving only 1 arm for FT tears, PT tears, or any tear, and the results remained stable.

CONCLUSION

This network meta-analysis of diagnostic tests revealed that high-field MRA had the highest diagnostic value for detecting any tear, followed by low-field MRA, high-field MRI, high-frequency US, low-field MRI, and low-frequency US. These findings can help guide clinicians in deciding on the appropriate imaging modality.

Diagnostic performance of shoulder magnetic resonance arthrography for labral tears having surgery as reference: comparison of high-resolution isotropic 3D sequence (THRIVE) with standard protocol

PURPOSE

To compare the diagnostic performance of T1 high-resolution isotropic volume excitation (THRIVE) sequence with that of a standard protocol for direct shoulder magnetic resonance arthrography (MRA) for the diagnosis of superior labral anterior-to-posterior (SLAP) and Bankart lesions, using arthroscopy findings as a reference standard.

MATERIALS AND METHODS

We retrospectively studied 84 patients who underwent direct shoulder 3T MRA using THRIVE and two-dimensional three-plane proton-density fat-suppressed (2D-PD-FS) sequences. One reviewer evaluated the contrast-to-noise ratio (CNR) as a quantitative image quality. Other two reviewers independently evaluated the subjective image noise, image sharpness, and radiologic diagnosis as qualitative image quality. Arthroscopic surgical findings were considered the reference standard. Wilcoxon rank sum, Chi-square/Fisher's exact, and DeLong's tests, as well as intraclass correlation coefficients (ICCs) were used to evaluate differences between THRIVE and 2D-PD-FS images.

RESULTS

THRIVE images had significantly higher CNR (p < 0.001), and subjective ratings of image noise (p = 0.009) and sharpness (p = 0.039) than 2D-PD-FS images (p < 0.001). THRIVE images had similar (p ≥ 0.18) diagnostic performance (sensitivity, 93.0-97.2%; specificity, 95.8-100%; accuracy, 95.2-97.6%) for the diagnosis of SLAP and Bankart lesions with excellent agreement (ICC = 0.898-0.942) when compared to 2D-PD-FS images (sensitivity, 86.1-91.7%; specificity, 93.8-95.8%; accuracy, 90.5-92.9%; agreement, ICC = 0.782-0.858). The scan time was reduced by 69% for THRIVE sequence compared to 2D-PD-FS sequence (2 min 40 s vs. 8 min 40 s).

CONCLUSION

The THRIVE sequence may be helpful in the diagnosis of SLAP and Bankart lesions, and may be routinely used during direct shoulder 3T MRA.

Usefulness of the fast spin-echo three-point Dixon (mDixon) image of the knee joint on 3.0-T MRI: comparison with conventional fast spin-echo T2 weighted image

OBJECTIVE

To compare the quality of two different imaging methods, three-point Dixon (mDixon) and fast spin-echo (FSE) T2 weighted image (T2WI) [and fat suppression (FS) T2WI], and to assess the utility of mDixon for the imaging of knee joint pathology.

METHODS

This retrospective study included 66 patients who underwent both mDixon and FSE T2WI (and FS T2WI) of the knee joint. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the two sequences at the articular cartilage and ligament were measured. Two radiologists independently evaluated the anatomic identification score and diagnostic performances of the two sequences.

RESULTS

The mean SNRs and CNRs of the patellar cartilage, femoral cartilage and anterior cruciate ligament (ACL) were significantly higher on T2WI and FS T2WI than on mDixon imaging, with the exception of the mean SNR of ACL on in-phase images. Most of the anatomic identification scores did not show significant differences, except for inferiorities of the in-phase mDixon in the evaluation of the cruciate ligament. There were no significant differences in sensitivity, specificity and accuracy between mDixon and T2WI regarding diagnostic performance.

CONCLUSION

mDixon images have equivalent anatomic identification ability with the exception of cruciate ligament delineation on in-phase images and have a diagnostic performance comparable with that of FSE T2WI for meniscal, cartilage and ligament injuries of the knee joint. There would be a net saving in time, if mDixon was the only sequence used.

ADVANCES IN KNOWLEDGE

The mDixon images have equivalent anatomic identification abilities, with the exception of cruciate ligament delineation on in-phase images and have a diagnostic performance comparable with that of FSE T2WI for meniscal, cartilage and ligament injuries of the knee joint.