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Objective: This study aimed to systematically review the gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI) findings of hepatocellular adenoma (HCA), especially focusing on the diagnostic value of low signal intensity (SI) in the hepatocyte-phase (HBP) for differentiating HCA from focal nodular hyperplasia (FNH). Methods: A thorough literature search was conducted in PubMed, Excerpta Medica Database (EMBASE) and China National Knowledge Infrastructure databases (CNKI) to identify studies evaluating Gd-EOB-DTPA-MRI presentations of HCA. Published studies using pathological examinations as the gold standard were included. The pooled proportions of low SI in the HBP, arterial-phase, portal venous-phase (PVP) in HCA were calculated, as well as pooled proportions of bleeding, fatty degeneration, and central scar. Meta-analysis was used to evaluate the diagnostic value of low SI in the HBP for HCA. Results: The search yielded 90 studies, with 8 assessing a total of 256 HCA cases included in this study, total of 229 lesions showed low signal in the HBP. Pooled proportions of low SI in the arterial-phase, PVP, and HBP were 2% (95% CI: 0.01-0.05), 39% (95% CI: 0.25-0.55), and 89% (95% CI: 0.80-0.94), respectively. Pooled proportions of bleeding, fatty degeneration, and central scar in HCA were 11% (95% CI: 0.03-0.19), 37% (95% CI: 0.27-0.49), and 10% (95% CI: 0.03-0.27), respectively. The meta-analysis revealed the following characteristics of low SI in the HBP for HCA diagnosis: 1) pooled sensitivity, 0.917 (95% CI: 0.86-0.96); 2) pooled specificity, 0.952 (95% CI: 0.91-0.98); 3) pooled positive likelihood ratio, 15.028 (95% CI: 7.10-31.82); 4) pooled negative likelihood ratio, 0.105 (95% CI: 0.07-0.17); 5) area under the ROC, 0.9802 (Q value of 0.9375), The sensitivity analysis showed that no single study was found to influence the overall pooled estimates significantly, which indicated the stability of the meta-analysis results were good. Conclusions: Low SI on the HBP of Gd-EOB-DTPA-MRI was helpful for the diagnosis of HCA and differentiating from FNH, but it was overvalued, especially for some HCA pathological subtypes. Combining low SI in the HBP with routine MRI presentations and the risk factors of liver diseases could substantially improve its diagnosis value for HCA as well as differential diagnosis.

Achilles tendinopathy is often attributed to overuse, but its pathophysiology remains poorly understood. Disruption to the molecular structure of collagen is fundamental for the onset and progression of tendinopathy but has mostly been investigated in vitro. Here, we interrogated the in vivo molecular structure changes of collagen in rat Achilles tendons following treadmill running. Unexpectedly, the tendons' collagen molecules were not mechanically unfolded by running but denatured through proteolysis during physiological post-run remodeling. We further revealed that running induces inflammatory gene expressions in Achilles tendons and that long-term running causes prolonged, elevated collagen degradation, leading to the accumulation of denatured collagen and tendinopathy development. For applications, we demonstrated magnetic resonance imaging of collagenase-induced Achilles tendon injury in vivo using a denatured collagen targeting contrast agent. Our findings may help close the knowledge gaps in the mechanobiology and pathogenesis of Achilles tendinopathy and initiate new strategies for its imaging-based diagnosis.

Objective: To develop and validate radiomics models based on non-enhanced magnetic resonance (MR) imaging for differentiating chondrosarcoma from enchondroma., Methods: We retrospectively evaluated a total of 68 patients (including 27 with chondrosarcoma and 41 with enchondroma), who were randomly divided into training group ( n =46) and validation group ( n =22). Radiomics features were extracted from T 1 WI and T 2 WI-FS sequences of the whole tumor by two radiologists independently and selected by Low Variance, Univariate feature selection, and least absolute shrinkage and selection operator (LASSO). Radiomics models were constructed by multivariate logistic regression analysis based on the features from T 1 WI and T 2 WI-FS sequences. The receiver-operating characteristics (ROC) curve and intraclass correlation coefficient (ICC) analyses of the radiomics models and conventional MR imaging were performed to determine their diagnostic accuracy., Results: The ICC value for interreader agreement of the radiomics features ranged from 0.779 to 0.923, which indicated good agreement. Ten and 11 features were selected from the T 1 WI and T 2 WI-FS sequences to construct radiomics models, respectively. The areas under the curve (AUCs) of T 1 WI and T 2 WI-FS models were 0.990 and 0.925 in training group and 0.915 and 0.855 in the validation group, respectively, showing no significant differences between the two sequence-based models ( P >0.05). In all the cases, the AUCs of the two radiomics models based on T 1 WI and T 2 WI-FS sequences and conventional MR imaging were 0.955, 0.901 and 0.569, respectively, demonstrating a significantly higher diagnostic accuracy of the two sequence-based radiomics models than conventional MR imaging ( P <0.01)., Conclusions: The radiomics models based on T 1 WI and T 2 WI-FS non-enhanced MR imaging can be used for the differentiation of chondrosarcoma from enchondroma.

Objective: To explore the clinical, pathological characteristics and imaging manifestations of brown tumors caused by hyperparathyroidism, to improve the cognition of the disease., Methods: The clinical, pathological characteristics and imaging manifestations of 15 cases of pathologically confirmed brown tumors were retrospectively reviewed. To analyze the imaging and pathological correlations, in addition, between the primary and secondary hyperparathyroidism led to brown tumors differential diagnoses. Rseults: In the 15 cases, aged from 26 to 66 years with median age of 51 years, 7 cases were caused by primary hyperparathyroidism, 8 cases secondary to long-term hemodialysis. Of the 15 cases(total of 34 lesions), 11 cases were multi-part bone involved. 13 of 15 patients for osteoporosis and 2 cases were osteosclerosis.32 lesions had bone destruction, 26 lesions showed expansive bone destruction, 6 showed soluble bone destruction, 12 lesions had harden edge. 23 lesions in bone destruction had calcification or ossification internal. 13 cases with soft tissue mass, enhanced significantly can be found in 3 cases. 2 lesions occured in the skull, bone density increased and the plate edge blur. pathological findings fibrous tissue , rich in blood vessels, scattered hemosiderin deposition, osteoid tissue around it., Conclusion: Brown tumor has relatively specific clinical history and laboratory characteristics. The imaging features include harden edge, in bone destruction has calcification or ossification internal and with soft tissue mass some enhanced significantly. The secondary brown tumor more multi-part destruction and more vertebra were involved than the primary.We can find osteosclerosis in secondary brown tumor. Those characteristic features were important to help for the diagnosis of the brown tumor.