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Magnetic resonance imaging (MRI) is a ubiquitous medical imaging technology with applications in disease diagnostics, intervention, and treatment planning. Accurate MRI segmentation is critical for diagnosing abnormalities, monitoring diseases, and deciding on a course of treatment. With the advent of advanced deep learning frameworks, fully automated and accurate MRI segmentation is advancing. Traditional supervised deep learning techniques have advanced tremendously, reaching clinical‐level accuracy in the field of segmentation. However, these algorithms still require a large amount of annotated data, which is oftentimes unavailable or impractical. One way to circumvent this issue is to utilize algorithms that exploit a limited amount of labeled data. This paper aims to review such state‐of‐the‐art algorithms that use a limited number of annotated samples. We explain the fundamental principles of self‐supervised learning, generative models, few‐shot learning, and semi‐supervised learning and summarize their applications in cardiac, abdomen, and brain MRI segmentation. Throughout this review, we highlight algorithms that can be employed based on the quantity of annotated data available. We also present a comprehensive list of notable publicly available MRI segmentation datasets. To conclude, we discuss possible future directions of the field—including emerging algorithms, such as contrastive language‐image pretraining, and potential combinations across the methods discussed—that can further increase the efficacy of image segmentation with limited labels. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI), particularly deep learning, has made enormous strides in medical imaging analysis. In the field of musculoskeletal radiology, deep-learning models are actively being developed for the identification and evaluation of bone fractures. These methods provide numerous benefits to radiologists such as increased diagnostic accuracy and efficiency while also achieving standalone performances comparable or superior to clinician readers. Various algorithms are already commercially available for integration into clinical workflows, with the potential to improve healthcare delivery and shape the future practice of radiology. In this systematic review, we explore the performance of current AI methods in the identification and evaluation of fractures, particularly those in the ankle, wrist, hip, and ribs. We also discuss current commercially available products for fracture detection and provide an overview of the current limitations of this technology and future directions of the field. [ABSTRACT FROM AUTHOR]

Introduction: The direct anterior approach (DAA) and the posterior approach (PA) are 2 common total hip arthroplasty (THA) exposures. This prospective study quantitatively compared changes in periarticular muscle volume after DAA and PA THA. Materials: 19 patients undergoing THA were recruited prospectively from the practices of 3 fellowship-trained hip surgeons. Each surgeon performed a single approach, DAA or PA. Enrolled patients underwent a preoperative MRI of the affected hip and two subsequent postoperative MRIs at around 6 weeks and 6 months after surgery. Clinical evaluations were done by Harris Hip Score at each follow-up interval. Results: MRIs or 10 DAA and 9 PA patients were analysed. Groups did not differ significantly with regard to BMI, age, or preoperative muscle volume. 1 DAA patient suffered a periprosthetic fracture and was excluded from the study. DAA hips showed significant atrophy in the obturator internus (−37.3%) muscle at early follow-up, with persistent atrophy of this muscle at the final follow-up. PA hips showed significant atrophy in the obturator internus (−46.8%) and externus (−16.0%), piriformis (−8.12%), and quadratus femoris muscles (−13.1%) at early follow-up, with persistent atrophy of these muscles at final follow-up. Loss of anterior capsular integrity was present at final follow-up in 2/10 DAA hips while loss of posterior capsular integrity was present in 5/9 PA hips. There was no difference in clinical outcomes. Discussion: This study demonstrates that DAA showed less persistent muscular atrophy than PA. Regardless of surgical approach, a muscle whose tendon is detached from its insertion is likely to demonstrate persistent atrophy 6 months following THA. Although the study was not powered to compare clinical outcomes, it should be noted that no significant difference in patient outcomes was observed. [ABSTRACT FROM AUTHOR]

For accurate diagnosis of interstitial lung disease (ILD), a consensus of radiologic, pathological, and clinical findings is vital. Management of ILD also requires thorough follow-up with computed tomography (CT) studies and lung function tests to assess disease progression, severity, and response to treatment. However, accurate classification of ILD subtypes can be challenging, especially for those not accustomed to reading chest CTs regularly. Dynamic models to predict patient survival rates based on longitudinal data are challenging to create due to disease complexity, variation, and irregular visit intervals. Here, we utilize RadImageNet pretrained models to diagnose five types of ILD with multimodal data and a transformer model to determine a patient's 3-year survival rate. When clinical history and associated CT scans are available, the proposed deep learning system can help clinicians diagnose and classify ILD patients and, importantly, dynamically predict disease progression and prognosis. Accurate diagnosis of interstitial lung disease subtypes and prediction of patient survival rates remains challenging. Here, the authors develop AI algorithms to combine patient's clinical history and longitudinal CT images to help clinicians diagnose and classify subtypes and dynamically predict disease progression and prognosis. [ABSTRACT FROM AUTHOR]

Background: There is a paucity of clinical studies that compare the efficacy of autograft and allograft in osteochondral transplantation for treatment of osteochondral lesions of the talus (OLT). The purpose of the present study was to compare the clinical and radiographic outcomes following osteochondral transplantation with autograft or allograft for OLT.Methods: A retrospective analysis comparing patients treated with autograft or allograft for OLT was performed. Clinical outcomes were evaluated with use of the Foot and Ankle Outcome Score (FAOS) and the Short Form-12 (SF-12) score. Magnetic resonance imaging (MRI) was evaluated with use of the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. The rates of cyst occurrence, graft degradation, graft failure, and revision surgeries were also evaluated.Results: Twenty-five nonrandomized patients with autograft and 16 with allograft were included, with a mean follow-up of 26 months in the autograft group and 22 months in the allograft group. There were no significant differences among all demographic variables between the autograft and allograft groups. The mean postoperative FAOS was significantly higher in the autograft group (81.9; 95% confidence interval [CI]: 78.6 to 85.2) than in the allograft group (70.1; 95% CI: 63.7 to 76.5; p = 0.006). Similarly, the mean postoperative SF-12 scores were significantly higher in the autograft group (74.7; 95% CI: 71.0 to 78.4) than in the allograft group (66.1; 95% CI: 61.2 to 71.0; p = 0.021). MOCART scores were significantly better in the autograft group (87.1) than in the allograft group (75.5; p = 0.005). The rate of chondral wear on MRI was higher in the allograft group (53%) than in the autograft group (4%; p < 0.001). Cyst formation in the graft itself was more likely to occur in the allograft group (47%) than in the autograft group (8%; p = 0.017). The rate of secondary procedures for the graft was higher in the allograft group (25%) than in the autograft group (0%; p = 0.009).Conclusions: In this small nonrandomized cohort study, the procedures performed with use of an autograft provided better clinical and MRI outcomes than the allograft procedures. The rate of chondral wear on MRI was higher with allograft than with autograft, and allograft-treated patients had a higher rate of clinical failure.Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Subchondral bone marrow edema (BME) has been associated with articular cartilage loss, with the potential to be a negative prognostic indicator for clinical outcomes after microfracture. However, no single study has investigated the association between BME and clinical outcomes after microfracture for osteochondral lesions of the talus (OLTs) at midterm follow-up. Purpose: To clarify the association between postoperative subchondral BME and clinical outcomes in patients treated with microfracture for OLTs at both short-term and midterm follow-up using a grading system that classified the extent of BME of the talus. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent microfracture between 2008 and 2013 were assessed at 2- and 4-year postoperative follow-up. BME was evaluated using magnetic resonance imaging, and the presence of subchondral BME was determined with fat-suppressed T2-weighted sequences. Clinical outcomes were evaluated using the Foot and Ankle Outcome Score (FAOS). P < .05 was considered to be statistically significant. Results: Forty-three (83%) of 52 eligible patients were included. No significant differences were found in the FAOS between the BME and no BME groups at 2-year follow-up (83.1 ± 6.5 vs 88.6 ± 8.0, respectively; P = .109), but there was a significant difference at 4-year follow-up (77.5 ± 11.1 vs 84.7 ± 8.4, respectively; P = .041). A significant difference was found among BME grades at 4-year follow-up (grade 0: 84.7 ± 7.4, grade 1: 80.1 ± 10.5, grade 2: 74.0 ± 10.3, and grade 3: 67.5 ± 7.1; P = .035). A post hoc analysis showed significant differences between grades 0 and 2, 0 and 3, and 1 and 3 (P = .041, .037, and .048, respectively). In addition, at 4-year follow-up, a significant correlation was noted between the FAOS and BME grade (r = −0.453, P = .003) but not at 2-year follow-up (r = −0.212, P = .178). Seventy-four percent of patients still had subchondral BME at 4-year follow-up after microfracture for OLTs. Conclusion: Patients with subchondral BME at midterm follow-up after microfracture for OLTs had worse clinical outcomes than those without subchondral BME. In addition, the degree of subchondral BME at midterm follow-up was correlated with clinical outcomes. However, at short-term follow-up, there were no significant differences in clinical outcomes based on both the presence and degree of BME, and no correlation was found between clinical outcomes and the degree of BME. The current study suggests that BME at short-term follow-up is a normal physiological reaction. However, BME at midterm follow-up after microfracture for OLTs may be pathological and is associated with poorer clinical outcomes. [ABSTRACT FROM AUTHOR]

Background: Uncontained-type osteochondral lesions of the talus (OLTs) have been shown to have inferior clinical outcomes after treatment with bone marrow stimulation. While autologous osteochondral transplantation (AOT) is indicated for larger lesions, no study has reported on the prognostic significance of the containment of OLTs treated with the AOT procedure. Purpose: To clarify the effect of the containment of OLTs on clinical and radiological outcomes in patients who underwent AOT for OLTs. Study Design: Case control study; Level of evidence, 3. Methods: A retrospective cohort study comparing patients with contained-type and uncontained-type OLTs was undertaken to include all patients who underwent AOT for the treatment of OLTs between 2006 and 2014. Analyses were performed by grouping the patients according to the containment type. Clinical outcomes were evaluated using the Foot and Ankle Outcome Score (FAOS) and the 12-Item Short Form Health Survey (SF-12) preoperatively and at final follow-up. Magnetic resonance imaging (MRI) at 2 years’ follow-up was evaluated with the modified magnetic resonance observation of cartilage repair tissue (MOCART) score. Multivariate regression models were used to evaluate factors affecting postoperative FAOS, SF-12, and MOCART scores. Results: Ninety-four patients were included: 31 patients with a contained-type OLT and 63 patients with an uncontained-type OLT. The median patient age was 34 years (interquartile range [IQR], 28-48 years) in the contained-type group and 36 years (IQR, 27-46 years) in the uncontained-type group. The median follow-up time was 45 months (IQR, 38-63 months) in the contained-type group and 52 months (IQR, 40-66 months) in the uncontained-type group. The median FAOS and SF-12 scores improved significantly after surgery in both contained-type and uncontained-type lesions (P < .001). The median postoperative FAOS score of patients with contained-type OLTs was higher than that of patients with uncontained-type OLTs (91.7 vs 85.0, respectively; P = .009), but no significant differences were found between the contained-type and uncontained-type groups for postoperative SF-12 and MOCART scores. The multivariate regression models showed that patients with contained-type OLTs had an approximately 10-point better score on the FAOS compared with patients with uncontained-type OLTs (P = .006). There was a nonsignificant trend for the rate of cystic occurrence in uncontained-type OLTs to be higher than that of contained-type OLTs (55.6% vs 38.7%, respectively; P = .125). Conclusion: Patients with contained-type OLTs experienced better clinical outcomes than those with uncontained-type OLTs after AOT for the treatment of OLTs. However, the AOT procedure still provided good clinical and MRI outcomes in both contained-type and uncontained-type OLTs at midterm follow-up. [ABSTRACT FROM AUTHOR]

Background: Microfracture is the most common cartilage-reparative procedure for the treatment of osteochondral lesions of the talus (OLTs). Damage to the subchondral bone (SCB) during microfracture may irreversibly change the joint-loading support of the ankle, leading to reparative fibrocartilage degradation over time. Purpose: To investigate the morphological change in the SCB after microfracture for OLT by developing a novel magnetic resonance imaging (MRI) scoring system specifically for evaluating the SCB. Furthermore, this study assesses the influence of the morphological changes of the SCB on clinical outcomes based on the new score. Study Design: Case series; Level of evidence, 4. Methods: Forty-two patients who underwent microfracture for OLT were included. An SCB Health (SCBH) scoring system was developed according to the amount of edema, subchondral cyst diameter, and qualitative and thickness change in the SCB, with a total score of 12 indicating normal SCB. MRI was obtained postoperatively from 6 months to 1 year, 1 to 2 years, 2 to 4 years, and 4 to 6 years. The Foot and Ankle Outcome Score (FAOS) was evaluated preoperatively and at 2 years and final follow-up. Results: The mean patient age was 38.4 ± 15.6 years, with a mean follow-up of 51.7 ± 22.8 months. The mean FAOS improved significantly from 57.8 ± 14.4 preoperatively to 84.3 ± 7.2 at 24 months (P < .001) and decreased to a final mean value of 77.1 ± 12.6 (P < .001). The mean SCBH score decreased from 8.6 ± 1.9 preoperatively to 7.1 ± 1.8 on the first follow-up MRI (P < .001) and significantly decreased to 5.9 ± 2.3 on the fourth follow-up MRI (P < .001). Subchondral cysts were noticeably worse at the fourth follow-up MRI than at the first and second (P < .001, P = .006, respectively). There was a positive correlation between the final FAOS and the SCBH score on the third and fourth follow-up MRI (r = 0.55, P < .001; r = 0.70, P < .001, respectively), but no correlation was found on the first and second follow-up. Conclusion: The SCBs following microfracture for OLT were not restored at midterm follow-up. There was a significant decrease of the overall SCBH score over time. Noticeably, subchondral cysts deteriorated over time consistently. In addition, the SCBH score at midterm follow-up was positively correlated with clinical outcomes. Lasting morphological changes in the SCB may be indicative of longer-term failure of the microfracture procedure. [ABSTRACT FROM AUTHOR]

Background: Osteochondral lesions of the distal tibial plafond are uncommon compared with talar lesions. The objective of this study was to assess functional and magnetic resonance imaging (MRI) outcomes following microfracture for tibial osteochondral lesions. Methods: Thirty-one tibial osteochondral lesions in thirty-one ankles underwent arthroscopic microfracture. The Foot and Ankle Outcome Score (FAOS) and Short Form-12 (SF-12) general health questionnaire were used to obtain patient-reported functional outcome scores preoperatively and postoperatively. MRI scans were assessed postoperatively with use of the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score for twenty-three ankles. Results: The average age was thirty-seven years (range, fifteen to sixty-eight years), and the average lesion area was 38 mm2 (range, 7.1 to 113 mm2). Twelve ankles had a kissing lesion on the opposing surface of the talus, and two ankles had a concomitant osteochondral lesion elsewhere on the talus. FAOS and SF-12 scores were significantly improved (p < 0.01) at the time of follow-up, at an average of forty-four months. The average postoperative MOCART score was 69.4 (range, 10 to 95), with a lower score in the ankles with kissing lesions (62.8) than in the ankles with an isolated lesion (73.6). Increasing age negatively impacted improvement in SF-12 (p < 0.01) and MOCART (p = 0.04) scores. Increasing lesion area was negatively correlated with MOCART scores (p = 0.04) but was not associated with FAOS or SF-12 scores. Lesion location and the presence of kissing lesions showed no association with functional or MRI outcomes. Conclusions: Arthroscopic microfracture provided functional improvements, but the optimal treatment strategy for tibial osteochondral lesions remains unclear. The repair tissue assessed on MRI was inferior to normal hyaline cartilage. The MRI outcomes appeared to deteriorate with increasing lesion area, and both functional and MRI outcomes appeared to deteriorate with increasing age. [ABSTRACT FROM AUTHOR]

The article discusses research which investigated patient outcomes associated with autologous osteochondral transplantation (AOT) in patients with cystic osteochondral lesions (OCL) of the talus. Topics addressed include the viability of AOT for large OCL that are not deemed amenable to marrow stimulation, the results of the clinical and magnetic resonance imaging (MRI) tests performed, and the postoperative complications recorded such as knee stiffness.

Introduction/Purpose: The purpose of this study is to evaluate the effectiveness of Extracellular Matrix Cartilage Allograft (EMCA) as an adjuvant to bone marrow stimulation (BMS) compared to BMS alone in the treatment of osteochondral lesions of the talus (OLT). Methods: A retrospective cohort study comparing patients treated with BMS with EMCA (BMS-EMCA group) and BMS alone (BMS group) between 2013 and 2019 was undertaken. Clinical outcome was evaluated with the Foot and Ankle Outcome Score (FAOS) pre-and postoperatively. Postoperative MRIs were evaluated using a modified Magnetic Resonance Observation of Cartilage Tissue (MOCART) score. Comparisons between groups were made with the Man-Whitney U test for continuous variables and the ?2 or Fisher exact test for categorical variables. Results: Twenty-four patients underwent BMS with EMCA (BMS-EMCA group) and 24 patients underwent BMS alone (BMS group). The mean age was 40.8 years (range, 19 to 60 years) in BMS-EMCA group and 47.8 years (range, 24 to 60 years) in BMS group (p=0.060). The mean follow-up time was 20.0 months (range, 12-36 months) in BMS-EMCA group and 26.9 months (range, 12 to 55 months) in BMS group (p=0.031). Both groups showed significant improvements in all FAOS subscales. No significant differences between groups were found in all postoperative FAOS. The mean MOCART score in BMS-EMCA group was higher (76.3 vs 66.3), but not statistically significant (p=0.176). The MRI analysis showed that 87.5% of BMS-EMCA group had complete infill of the defect with repair tissue, however less than half (46.5%) of BMS group had complete infill (p=0.015). Conclusion: BMS with EMCA is an effective treatment strategy for the treatment of OLT and provides better cartilage infill in the defect on MRI. However, this did not translate to improved functional outcomes compared with BMS alone in the short-term. [ABSTRACT FROM AUTHOR]

Introduction/Purpose: Microfracture has been widely published as a treatment modality for osteochondral lesions of the talus (OLT). However, little is known about the outcome predictors following microfracture for smaller-sized OLT (<100mm2). This study sought to define the predictors of both clinical and magnetic resonance imaging (MRI) outcomes for small OLT treated with microfracture. Methods: A retrospective cohort study investigating patients who received arthroscopic microfracture for OLT (<10mm or 100mm2) between 2008 and 2017 were evaluated. Multivariate regression models were used to evaluate factors affecting postoperative Foot and Ankle Outcome Scores (FAOS) and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scores. Kaplan-Meier survival curves with log-rank test were constructed and endpoint was defined as the requirement of revision surgery. Results: Eighty-seven patients were included in the study. The mean follow-up time was 41.4+-28.7 months. The mean FAOS pain score significantly improved from 60.4+-14.8 preoperatively to 79.3+-12.8 at final follow-up (p<0.001). Patients with uncontainedtype OLT had an approximately 9-point worse FAOS pain score compared to contained-type OLT (p=0.036). Patients with cystic OLT also had an approximately 9-point worse pain FAOS compared to non-cystic OLT (p=0.026). Patients with larger lesion sizes had worse postoperative MOCART scores (p=0.012). Both Uncontained-Cyst and Uncontained-Noncyst groups had significantly worse FAOS pain than the Contained-Noncyst group (p<0.001, p=0.026). Survival rates in uncontained and contained lesions were 51.5% and 84.4%, respectively (p=0.616). Conclusion: Lesion uncontainment and the existence of cysts are independent predictors of poor clinical outcome following arthroscopic microfracture for smaller-sized OLT (<100mm2). [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to retrospectively evaluate a large series of patients for functional, radiographic and MRI outcomes after a Chevron-type medial malleolar osteotomy. Methods: Sixty-two patients underwent a Chevron-type medial malleolar osteotomy with a median follow-up of 34.5 months. Standard digital radiographs were used to determine bony union and the angle of the osteotomy relative to the longitudinal axis of the tibia. Morphologic and quantitative T2-mapping MRI was also analysed in 32 patients. Results: Fifty-eight patients (94 %) reported being asymptomatic at the site of the medial malleolar osteotomy. The median time to healing on standard radiograph was 6 weeks (range, 4-6 weeks) with an angle of 31.7° ± 6.9°. Quantitative T2-mapping MRI analysis demonstrated that the deep half of interface repair tissue had relaxation times that were not significantly different from normal tibial cartilage. In contrast, interface repair tissue in the superficial half demonstrated significant prolongation from normal relaxation time values, indicating a more fibrocartilaginous repair. Four patients (6 %) reported pain post-operatively. Conclusion: A Chevron-type medial malleolar osteotomy demonstrates satisfactory healing and fixation, with fibrocartilaginous tissue evident superficially at the osteotomy interface. Further investigation is warranted in the form of longitudinal study to assess the long-term outcomes of medial malleolar osteotomy. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

We describe a case of endovascular exclusion of a splenic artery aneurysm. The repair utilized a novel balloon-expandable stent-graft. [ABSTRACT FROM AUTHOR]