A new modified MR dual precision positioning of thin-slice oblique sagittal fat suppression proton density weighted imaging: its diagnostic accuracy in anterior cruciate ligament injury

To evaluate the diagnostic accuracy of a new modified MR dual precision positioning of thin-slice oblique sagittal fat suppression proton density-weighted imaging (DPP-TSO-Sag-FS-PDWI) sequence in detecting ACL injuries and its grades compared to standard sequences using arthroscopy as the standard reference. 42 patients enrolled in this retrospective study received the 1.5-T MRI with standard sequences and the new modified DPP-TSO-Sag-FS-PDWI sequence, and their arthroscopy results was recorded. The Mc Nemer-Bowker and weighted Kappa was performed to compare the consistency of MRI diagnosis with arthroscopic results. Finally, the diagnostic accuracy was calculated based on the true positive, true negative, false negative and false positive values. The diagnostic consistency of the DPP-TSO-Sag-FS-PDWI were higher than standard sequences for both reader 1 (K = 0.876 vs. 0.620) and reader 2 (K = 0.833 vs. 0.683) with good diagnostic repeatability (K = 0.794 vs. 0.598). Furthermore, the DPP-TSO-Sag-FS-PDWI can classify and diagnose three grades of ACL injury [the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value were more than 84%], especially for grade II injury as the PPV was superior for reader 1 (92.3% vs. 53.9%) and reader 2 (84.6% vs. 69.2%). The new modified DPP-TSO-Sag-FS-PDWI sequence can display the ACL injury on one or continuous levels by maximizing the acquisition of complete ligament shape and true anatomical images, and excluding the influence of anatomical differences between individuals. It can improve the diagnostic accuracy with good repeatability and classify three grades of the ACL injury.

A transfer learning approach for staging diagnosis of anterior cruciate ligament injury on a new modified MR dual precision positioning of thin-slice oblique sagittal FS-PDWI sequence

PURPOSE

To evaluate the diagnostic performance of the transfer learning approach for grading diagnosis of ACL injury on a new modified dual precision positioning of thin-slice oblique sagittal FS-PDWI (DPP-TSO-Sag-FS-PDWI) sequence. And compare the prediction performances between artificial intelligence (AI) and radiologists.

MATERIALS AND METHODS

Patients with both DPP-TSO-Sag-FS-PDWI sequence and arthroscopic results were included. We performed a transfer learning approach using the pre-trained EfficientNet-B0 model, including whole image and regions of interest (ROI) image inputs, and reset its parameters to achieve an automatic hierarchical diagnosis of ACL.

RESULTS

A total of 235 patients (145 men and 90 women, 37.91 ± 14.77 years) with 665 images were analyzed. The consistencies of AI and arthroscopy (Kappa value > 0.94), radiologists and arthroscopy (Kappa value > 0.83, p = 0.000) were almost perfect. No statistical difference exists between the whole image and radiologists in the diagnosis of normal ACL (p = 0.063) and grade 3 injury (p = 1.000), while the whole image was better than radiologists in grade 1 (p = 0.012) and grade 2 injury (p = 0.003).

CONCLUSION

The transfer learning approach exhibits its feasibility in the diagnosis of ACL injury based on the new modified MR DPP-TSO-Sag-FS-PDWI sequence, suggesting that it can help radiologists hierarchical diagnose ACL injuries, especially grade 2 injury.

Cyclops lesions associated with both bundles and selective bundle repair of the anterior cruciate ligament

BACKGROUND

The remnant of a ruptured anterior cruciate ligament (ACL) can increase the risk of impingement or a cyclops lesion, which can increase challenges to proper tunnel placement.

PURPOSE

To evaluate the prevalence of cyclops lesions after ACL reconstruction and to assess the difference in the incidence of cyclops lesions between single-bundle repair and selective bundle repair of the ACL.

MATERIAL AND METHODS

This retrospective study included 151 patients who were diagnosed with an ACL tear after knee joint magnetic resonance imaging (MRI) who underwent ACL reconstruction surgery. MRI diagnosis of cyclops lesion formation was made if a soft-tissue mass was seen anteriorly in the intercondylar notch near the tibial insertion of the reconstructed ACL, based on sagittal T2-weighted (T2W) imaging. The size of the cyclops lesions was recorded as the largest diameter on the sagittal T2W imaging.

RESULTS

A cyclops lesion was detected in 74 (38.5%) cases. Cyclops lesions were detected more frequently in cases with single-bundle repair of the ACL, but the results were not statistically significant (P = 0.609). Compared with selective bundle repair, cyclops lesions had a significantly higher prevalence in the posterolateral (PL) bundle repair than in the anteromedial (AM) bundle repair (P = 0.027) based on MR images at 6-12 months after surgery.

CONCLUSION

The incidence of cyclops lesions did not differ significantly in single-bundle repair and selective bundle repair of ACL. However, selective PL bundle repair of the ACL showed a significantly increased incidence of cyclops lesions compared with selective AM bundle repair.

Anterior cruciate ligament reconstruction related complications: 2D and 3D high-resolution magnetic resonance imaging evaluation

Anterior cruciate ligament (ACL) injury is a common indication for sports-related major surgery and accounts for a large proportion of ligamentous injuries in athletes. The advancements in 2D and 3D MR imaging have provided considerable potential for a one-stop shop radiation-free assessment with an all-in-one modality examination of the knee, for both soft-tissue and bone evaluations. This article reviews ACL injuries and types of surgical managements with illustrative examples using high resolution 2D and 3D MR imaging. Various complications of ACL reconstruction procedures are highlighted with a focus on the use of advanced MR imaging and relevant arthroscopic correlations.

Prevalence of anterolateral ligament injuries and lateral meniscus tear on MR imaging in patients with both-bundle tear vs. selective bundle incomplete tear of the anterior cruciate ligament

OBJECTIVES

We investigated the prevalence of anterolateral ligament (ALL) injury and lateral meniscus (LM) tear in cases with both-bundle tear and selective bundle incomplete tear of the anterior cruciate ligament (ACL).

METHODS

A total of 174 cases of magnetic resonance (MR) images that had an ACL tear and underwent arthroscopic ACL reconstruction were retrospectively reviewed. ACL injury was classified into both bundle, anteromedial bundle, and posterolateral bundle (PL) on arthroscopic finding. The ALL was divided into three portions: femoral, meniscal, and tibial. ALL injury was scored into three groups: grade 0 is intact; grade 1 is stranding and edema surrounds the expected location of the ALL; grade 2 is clear discontinuity of the ALL consistent with rupture. Traumatic LM tear was also assessed on MR images.

RESULTS

The total prevalence of ALL injury was 36.2% (reader 1) and 42.0% (reader 2). ALL injury was statistically related to the selective bundle tear (p = 0.002 and 0.004, readers 1 and 2). PL bundle tear was significantly correlated with the ALL injury (p value < 0.001, readers 1 and 2, both). The location and grade of ALL injury were not significantly correlated with the type of ACL injury. LM tear was not significantly related to the types of ACL tear (p = 0.208 and 0.907, readers 1 and 2) and ALL injury (p value = 0.096 and 0.383, readers 1 and 2).

CONCLUSIONS

ALL injury was significantly related to the PL bundle tear of the ACL. LM tear was not significantly correlated with the types of ACL injury and ALL injury.

KEY POINTS

• Anterolateral ligament (ALL) injury was significantly related to the posterolateral bundle (PL) tear of the anterior cruciate ligament (ACL). • Lateral meniscus (LM) tear was not significantly correlated with the types of ACL injury and ALL injury. • Clinicians and radiologists should be aware of these relationships and scrutinize ALL injury in cases with PL bundle tears, even with an incomplete ACL injury.

Assessment of the Usefulness of Image Reconstruction in the Oblique and Double-oblique Sagittal Planes for Magnetic Resonance Imaging of the Canine Cranial Cruciate Ligament

Introduction

The aim of the study was to determine the quality and significance of the magnetic resonance image of the canine knee after reconstruction in the oblique and double-oblique sagittal plane. This reconstruction and 3D images are rarely used in common protocols due to the longer study time they require. The study aimed to demonstrate significance for such diagnostic images in specific sequences in order to stimulate consideration of their more frequent use in diagnosis of diseases of the cruciate ligament in dogs.

Material and Methods

All tests were carried out using an open magnetic resonance tomography scanner with magnetic field induction. The images obtained from the 30 canine patients examined were reconstructed and evaluated by independent appraisers. Statistical analysis was performed.

Results

The study showed that MRI of the stifle joint using 3D sequences provides higher quality images of the cranial cruciate ligament in dogs. The results of the statistical analysis showed that multi-faceted reconstruction allows the secondary determination of the oblique imaging planes and obtains images of adequate quality.

Conclusion

It can be concluded that multi-faceted reconstruction facilitates the secondary determination of oblique imaging planes. This reconstruction additionally makes images available of better quality compared to the 2D sequence.

Intra-articular and meniscal pathology according to anterior cruciate ligament injury pattern: both-bundle tear or selective bundle tear

Background

Articular cartilage injury and meniscal tear are usually combined with anterior cruciate ligament injury.

Purpose

We investigated the incidence of cartilage injury and traumatic meniscal tear according to the type of combined anterior cruciate ligament tear (both-bundle versus selective bundle tear).

Material and Methods

This retrospective study included 103 patients diagnosed with anterior cruciate ligament tear after knee joint magnetic resonance imaging and who underwent knee joint arthroscopy. Two radiologists evaluated articular cartilage injuries and meniscal tear independently. We used the chi-square test to analyze the association between type of anterior cruciate ligament bundle tear and presence of cartilage or meniscal injury in each reader.

Results

Cartilage injury presented a significantly higher prevalence in both-bundle tear than did selective bundle tear in reader 1 ( P = 0.004). In reader 2, both-bundle tear had a tendency for higher risk of cartilage injury, but this was not statistically significant ( P = 0.178). In meniscal injury, there was a statistically significant increase in the risk of associated meniscal injury in both-bundle tear versus selective bundle anterior cruciate ligament injury ( P = 0.019 and 0.021). The risk of accompanying traumatic meniscal lesion was significantly higher in both-bundle tear ( P = 0.036 and 0.018).

Conclusion

The incidence of accompanying meniscal injury, especially traumatic tears, is higher in both-bundle anterior cruciate ligament tear than in selective bundle tear. There was no significant difference in incidence of cartilage injury between both-bundle tear and selective bundle tear, although one of two readers showed a higher incidence in both-bundle tear.

Types of posterolateral corner injury associated with both bundle and selective-bundle ACL tears

BACKGROUND

It is unknown whether a selective-bundle tear of the anterior cruciate ligament (ACL) shows a different prevalence of posterolateral corner (PLC) injury than a both-bundle tear.

PURPOSE

The prevalence of injury of PLC stabilizer in relation to the type of combined ACL tear (both-bundle and selective-bundle tears) has been investigated.

MATERIAL AND METHODS

This retrospective study included 94 patients who were diagnosed with an ACL tear after knee joint magnetic resonance imaging and underwent arthroscopic surgery. We compared the prevalence of each lesion in relation to the type of ACL injury and the type of selective-bundle tear. We used Fischer exact tests to compare the prevalence of each lesion in relation to the type of ACL injury and the type of selective-bundle tear.

RESULTS

Both-bundle tears occurred in 55 cases (56%) and selective-bundle tears in 39 cases (44%). The most common PLC injury with an ACL tear was inferior popliteomeniscal fascicle (PMF) injury, followed by superior PMF injury. The prevalence of each PLC injury was higher for both-bundle tears than selective-bundle tears, with the exception of popliteus tendon injury diagnosed by reader 1 (P.H.J). However, these differences were statistically significant for superior PMF injury only ( p < 0.05). The prevalence of PLC injury was unrelated to the type of selective-bundle tear (anteromedial vs posterolateral).

CONCLUSION

Superior PMF injury is more common in both-bundle tears than selective-bundle tears. There is no statistically significant difference in the prevalence of PLC injury between both-bundle tears and selective-bundle tears.

The rotating stretched curved planar reconstruction of 3D-FIESTA MR imaging for evaluating the anterior cruciate ligament of the knee joint

PURPOSE

To determine the feasibility of the rotating stretched curved planar reconstruction (CPR) of three-dimensional fast imaging with steady-state acquisition magnetic resonance imaging (3D-FIESTA MRI) for evaluating the anterior cruciate ligament of the knee joint.

MATERIALS AND METHODS

MRI of 40 knee joints in healthy volunteers was performed on a 3.0-T MR scanner and a phased-array extremity coil. The protocol consisted of oblique sagittal spin echo (SE) T1WI, coronal FS-PDWI, axial FS-FSE-T2WI, and 3D-FIESTA sequences. The rotating stretched curved planar reconstructions (CPR) of the ACL at angles of 0°, 30°, 60°, 90°, 120°, 150°, and 180° were generated from images of 3D-FIESTA sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the 3D-FIESTA were compared with those of the oblique sagittal SE T1WI sequence. The presence of the tibial attachment, midportion, femoral attachment, and double bundles of the ACL on the oblique sagittal SE T1WI and CPR of 3D-FIESTA MR imaging were divided into two categories: visible and not visible.

RESULTS

The ACL SNR efficiency of 3D-FIESTA sequences was significantly higher than that of oblique sagittal SE T1WI sequence (P < 0.05). The 3D-FIESTA sequences produced images with a significantly higher CNR between ACL and synovial fluid than did the oblique sagittal SE T1WI sequence (P < 0.05). CPR of 3D-FIESTA MRI generated an excellent visualization of the ACL. The CPR of 3D-FIESTA MRI was rated superior to oblique sagittal SE T1WI sequence in 60% and 65% of cases with regard to the tibial attachment and midportion of ACL, respectively (P < 0.05). CPR of 3D-FIESTA MR imaging was rated superior to oblique sagittal SE T1WI sequence in 80% and 85% of cases with regard to femoral attachment and double bundles of ACL, respectively (P < 0.05).

CONCLUSION

The rotating stretched curved planar reconstruction of 3D-FIESTA sequences is significantly better than that of conventional 2D-MRI in evaluating the native ACL and its components, AM bundle and PL bundle, in healthy volunteers.