Quantitative magnetic resonance imaging (MRI) evaluation of cartilage repair after microfracture treatment for full-thickness cartilage defect models in rabbit knee joints: correlations with histological findings

The Value of CT 3D Reconstruction in the Classification and Nursing Effect Evaluation of Ankle Fracture

Aim

To study the application value of ankle fracture classification and diagnosis. In this paper, the clinical data of 100 cases of ankle fracture patients admitted from May 2020 to May 2021 were analyzed by CT 3D reconstruction. All patients received surgical treatment and underwent spiral CT 3D reconstruction and X-ray examination before surgery. The results showed that 20 cases (20.00%) of the 100 cases were PER, 24 cases (24%) of the 100 cases were PAB, 31 cases (31%) of the 100 cases were SER, and 25 cases (25%) of the 100 cases were SAB, respectively.

Conclusion

The diagnostic accuracy of CT 3D reconstruction for different types of ankle fracture is higher than that of X-ray, and the differences are statistically significant (P < 0.05). CT 3D reconstruction is applied in the early diagnosis of ankle fracture, which can accurately detect the classification of patients. It has important clinical application value and can be used as the first choice for the early classification diagnosis of ankle fracture.

Articular Cartilage Repair in the Knee: Postoperative Imaging

Diagnostic and therapeutic advancements have improved clinical outcomes for patients with focal chondral injuries of the knee. An increased number and complexity of surgical treatment options have, in turn, resulted in a commensurate proliferation of patients requiring postoperative evaluation and management. In addition to patient-reported clinical outcomes, magnetic resonance imaging (MRI) offers clinicians with noninvasive, objective data to assist with postoperative clinical decision making. However, successful MRI interpretation in this setting is clinically challenging; it relies upon an understanding of the evolving and procedure-specific nature of normal postoperative imaging. Moreover, further research is required to better elucidate the correlation between MRI findings and long-term clinical outcomes. This article focuses on how specific morphologic features identified on MRI can be utilized to evaluate patients following the most commonly performed cartilage repair surgeries of the knee.

Magnetic Resonance Imaging Evaluation of Cartilage Repair and Iron Particle Kinetics After Magnetic Delivery of Stem Cells

IMPACT STATEMENT

This study is very important as a preclinical study of magnetic resonance imaging (MRI) assessment after magnetic targeting of mesenchymal stem cells. The findings of this study show that MRI is useful for evaluating the regenerative process of cartilage with magnetic targeting and kinetics of iron particles, and is less invasive without any complications.

Three-Dimensional Quantitative Morphometric Analysis (QMA) for In Situ Joint and Tissue Assessment of Osteoarthritis in a Preclinical Rabbit Disease Model

This work utilises advances in multi-tissue imaging, and incorporates new metrics which define in situ joint changes and individual tissue changes in osteoarthritis (OA). The aims are to (1) demonstrate a protocol for processing intact animal joints for microCT to visualise relevant joint, bone and cartilage structures for understanding OA in a preclinical rabbit model, and (2) introduce a comprehensive three-dimensional (3D) quantitative morphometric analysis (QMA), including an assessment of reproducibility. Sixteen rabbit joints with and without transection of the anterior cruciate ligament were scanned with microCT and contrast agents, and processed for histology. Semi-quantitative evaluation was performed on matching two-dimensional (2D) histology and microCT images. Subsequently, 3D QMA was performed; including measures of cartilage, subchondral cortical and epiphyseal bone, and novel tibio-femoral joint metrics. Reproducibility of the QMA was tested on seven additional joints. A significant correlation was observed in cartilage thickness from matching histology-microCT pairs. The lateral compartment of operated joints had larger joint space width, thicker femoral cartilage and reduced bone volume, while osteophytes could be detected quantitatively. Measures between the in situ tibia and femur indicated an altered loading scenario. High measurement reproducibility was observed for all new parameters; with ICC ranging from 0.754 to 0.998. In conclusion, this study provides a novel 3D QMA to quantify macro and micro tissue measures in the joint of a rabbit OA model. New metrics were established consisting of: an angle to quantitatively measure osteophytes (σ), an angle to indicate erosion between the lateral and medial femoral condyles (ρ), a vector defining altered angulation (λ, α, β, γ) and a twist angle (τ) measuring instability and tissue degeneration between the femur and tibia, a length measure of joint space width (JSW), and a slope and intercept (m, Χ) of joint contact to demonstrate altered loading with disease progression, as well as traditional bone and cartilage and histo-morphometry measures. We demonstrate correlation of microCT and histology, sensitive discrimination of OA change and robust reproducibility.

Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities

This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available.

Non-Gaussian diffusion MR imaging of glioma: comparisons of multiple diffusion parameters and correlation with histologic grade and MIB-1 (Ki-67 labeling) index

INTRODUCTION

This study was conducted to compare the association of Gaussian and non-Gaussian magnetic resonance imaging (MRI)-derived parameters with histologic grade and MIB-1 (Ki-67 labeling) index (MI) in brain glioma.

METHODS

Sixty-five patients with pathologically confirmed glioma, who underwent diffusion-weighted MRI with 2 b values (0, 1000 s/mm(2)) and 22 b values (≤5000 s/mm(2)), respectively, were divided into three groups of grade II (n = 35), grade III (n = 8), and grade IV (n = 22). Comparisons by two groups were made for apparent diffusion coefficient (ADC), slow diffusion coefficient (Dslow), distributed diffusion coefficient (DDC), and heterogeneity index α. Analyses of receiver operating characteristic (ROC) curve were performed to maximize the area under the curve (AUC) for differentiating grade III + IV (high-grade glioma, HGG) from grade II (low-grade glioma, LGG) and grade IV (glioblastoma multiforme, GBM) from grade II + III (other grade glioma, OGG). Correlations with MI were analyzed for the MRI parameters.

RESULTS

On tumor regions, the values of ADC, Dslow, DDC, and α were significantly higher in grade II [(1.37 ± 0.29, 0.70 ± 0.11, 1.39 ± 0.34) (×10(-3) mm(2)/s) and 0.88 ± 0.05, respectively] than in grade III [(0.99 ± 0.13, 0.55 ± 0.07, 1.04 ± 0.20) (×10(-3) mm(2)/s) and 0.80 ± 0.03, respectively] and grade IV [(1.03 ± 0.14, 0.50 ± 0.05, 1.02 ± 0.16) (×10(-3) mm(2)/s) and 0.76 ± 0.04, respectively] (all P < 0.001). The parameter α showed the highest AUCs of 0.950 and 0.922 in discriminating HGG from LGG and GBM from OGG, respectively. Significant correlations with histologic grade and MI were observed for the MRI parameters.

CONCLUSION

The non-Gaussian MRI-derived parameters α and Dslow are superior to ADC in glioma grading, which are comparable with ADC as reliable biomarkers in noninvasively predicting the proliferation level of glioma malignancy.