Imaging in sports-medicine--knee

Application research of AI-assisted compressed sensing technology in MRI scanning of the knee joint: 3D-MRI perspective

OBJECTIVE

To investigate the potential applicability of AI-assisted compressed sensing (ACS) in knee MRI to enhance and optimize the scanning process.

METHODS

Volunteers and patients with sports-related injuries underwent prospective MRI scans with a range of acceleration techniques. The volunteers were subjected to varied ACS acceleration levels to ascertain the most effective level. Patients underwent scans at the determined optimal 3D-ACS acceleration level, and 3D compressed sensing (CS) and 2D parallel acquisition technology (PAT) scans were performed. The resultant 3D-ACS images underwent 3.5 mm/2.0 mm multiplanar reconstruction (MPR). Experienced radiologists evaluated and compared the quality of images obtained by 3D-ACS-MRI and 3D-CS-MRI, 3.5 mm/2.0 mm MPR and 2D-PAT-MRI, diagnosed diseases, and compared the results with the arthroscopic findings. The diagnostic agreement was evaluated using Cohen's kappa correlation coefficient, and both absolute and relative evaluation methods were utilized for objective assessment.

RESULTS

The study involved 15 volunteers and 53 patients. An acceleration factor of 10.69 × was identified as optimal. The quality evaluation showed that 3D-ACS provided poorer bone structure visualization, and improved cartilage visualization and less satisfactory axial images with 3.5 mm/2.0 mm MPR than 2D-PAT. In terms of objective evaluation, the relative evaluation yielded satisfactory results across different groups, while the absolute evaluation revealed significant variances in most features. Nevertheless, high levels of diagnostic agreement (κ: 0.81-0.94) and accuracy (0.83-0.98) were observed across all diagnoses.

CONCLUSION

ACS technology presents significant potential as a replacement for traditional CS in 3D-MRI knee scans, allowing thinner MPRs and markedly faster scans without sacrificing diagnostic accuracy.

CLINICAL RELEVANCE STATEMENT

3D-ACS-MRI of the knee can be completed in the 160 s with good diagnostic consistency and image quality. 3D-MRI-MPR can replace 2D-MRI and reconstruct images with thinner slices, which helps to optimize the current MRI examination process and shorten scanning time.

KEY POINTS

• AI-assisted compressed sensing technology can reduce knee MRI scan time by over 50%. • 3D AI-assisted compressed sensing MRI and related multiplanar reconstruction can replace traditional accelerated MRI and yield thinner 2D multiplanar reconstructions. • Successful application of 3D AI-assisted compressed sensing MRI can help optimize the current knee MRI process.

Assessing medial collateral ligament knee lesions in general practice

PURPOSE

To assess the diagnostic value of history-taking and physical examination of medial collateral ligament lesions after a knee injury presenting in general practice.

METHODS

Patients aged 18 to 65 years with a traumatic knee injury who consulted their general practitioner within 5 weeks after trauma filled out a questionnaire, underwent a standardized physical examination, and underwent a magnetic resonance imaging scan. Logistic regression analysis was used to test possible associations between determinants from history-taking/physical examination and medial collateral ligament lesions. The diagnostic value of history-taking and physical examination was determined for those variables indicating an association (P <.15) with medial collateral ligament lesions and was assessed by sensitivity, specificity, predictive value, and likelihood ratios.

RESULTS

Of the 134 patients included in this study, 35 had a medial collateral ligament lesion seen on magnetic resonance imaging scan. From history-taking, the determinants "trauma by external force to leg" and "rotational trauma" showed an association with medial collateral ligament lesion after multivariate analysis (P <.15). From physical examination, "pain valgus stress 30 degrees " and "laxity valgus stress 30 degrees " showed an association (P <.15). Isolated determinants from history-taking and physical examination showed some diagnostic value; the likelihood ratio positive was 2.0 for "trauma by external force to leg" and 2.3 for "pain valgus stress 30 degrees ." Adding "pain valgus stress 30 degrees " and "laxity valgus stress 30 degrees " from physical examination to history-taking improved the diagnostic value to a likelihood ratio positive of 6.4.

CONCLUSION

Medial collateral ligament lesions are frequently seen in patients with traumatic knee injury. History-taking has a diagnostic value, while adding physical examination increases the diagnostic value.

Diagnostic value of history-taking and physical examination for assessing meniscal tears of the knee in general practice

OBJECTIVE

To assess the diagnostic value of history-taking and physical examination of meniscal tears in general practice.

DESIGN

An observational study determining diagnostic values (sensitivity, specificity, predictive value, and likelihood ratios).

SETTING

General practice.

PATIENTS

Consecutive patients aged 18 to 65 years with a traumatic knee injury who consulted their general practitioner within 5 weeks after trauma.

ASSESSMENT

Participating patients filled out a questionnaire (history-taking) followed by a standardized physical examination.

MAIN OUTCOME

Assessment of meniscal tears was determined by means of magnetic resonance imaging (MRI) and was performed blinded for the results of physical examination and history-taking.

RESULTS

Of the 134 patients included in this study, 47 had a meniscal tear. From history-taking, the determinants "age over 40 years," "continuation of activity impossible," and "weight-bearing during trauma" indicated an association with a meniscal tear after multivariate logistic regression analysis, whereas from physical examination only "pain at passive flexion" indicated an association. These associated determinants from history-taking showed some diagnostic value; the positive likelihood ratio (LR+) reached up to 2.0 for age over 40 years, whereas the isolated test pain at passive flexion from physical examination has less diagnostic value, with an LR+ of 1.3. Combining determinants from history-taking and physical examination improved the diagnostic value with a maximum LR+ of 5.8; however, this combination only applied to a limited number of patients.

CONCLUSION

History-taking has some diagnostic value, whereas physical examination did not add any diagnostic value for detecting meniscal tears in general practice.

MRI of overuse injury in elite athletes

Overuse injuries are a common finding in elite athletes. Magnetic resonance imaging (MRI) is the optimal method for the diagnosis of overuse injury in athletes of all levels. We present a review of common and important overuse injuries occurring in elite athletes. A systematic approach based on the functional anatomic units - tendons, bones and joints - may assist in diagnosis of these injuries.

Clinical decision making in the acutely injured knee based on repeat clinical examination and MRI

To determine the correlation between Magnetic Resonance Imaging (MRI) and clinical examination of the knee after an acute injury, and to see to what extent MRI affected the planned treatment, we examined 90 consecutive patients in a prospective study, clinically and with an extremity Magnetic Resonance (MR) scanner. The number of meniscal lesions, bone bruises and osteochondral lesions found on MRI was significantly higher than the clinical examinations indicated. Despite this, the treatment was only changed in 6 cases. In no case did MRI prevent a planned arthroscopy. MRI may reveal many clinically silent changes in the knee, also after minor injuries. The significance of these MRI findings must await long-term follow-up.