T1-weighted images-based radiomics for structural lesions evaluation in patients with suspected axial spondyloarthritis.

PURPOSE: The aim of this study was to investigate the feasibility of radiomics based on T1-weighted images (T1WI) for assessing sacroiliac joint (SIJ) structural lesions in patients with suspected axial spondyloarthritis (axSpA). MATERIALS AND METHODS: A total of 266 patients with clinical suspicion of axSpA between December 2016 and January 2022 were enrolled. Structural lesions were assessed on low-dose CT (ldCT) and MRI, respectively. Radiomic features, extracted from SIJ T1WI, were included to generate the radiomics model. The performance of the radiomics model was evaluated using receiver operating characteristic (ROC) curve. Furthermore, point-biserial correlation analysis was used to interpret the associations between the radiomic feature and structural lesions. RESULTS: Using ldCT as the reference standard, the radiomics model showed favorable performance for detecting positive global structural lesions in the training cohort (AUC, 0.82 [95% CI: 0.76, 0.88]) and validation cohort (AUC, 0.82 [95% CI: 0.72, 0.91]. Experienced MRI raters yielded predictive AUCs of 0.73 (95% CI: 0.67, 0.79), and 0.74 (95% CI: 0.66, 0.83) in the training and validation cohort, respectively. The seven radiomic features included in the radiomics model showed significant correlation with different kinds of structural lesions (P all < 0.05). Among them, Wavelet.LHL_firstorder_90Percentile showed the strongest association with fat lesion (r = 0.48, P < 0.05). CONCLUSION: The radiomics analysis with T1WI could effectively detect SIJ structural lesions and achieved expert-level performance. Each radiomic feature was correlated with different structural lesions significantly, which might inform radiomic-based applications for axSpA intelligent diagnosis.

Can radiomics replace the SPARCC scoring system in evaluating bone marrow edema of sacroiliac joints in patients with axial spondyloarthritis?

OBJECTIVES: To develop an objective and efficient method based on radiomics to evaluate bone marrow edema (BMO) of sacroiliac joints (SIJs) by magnetic resonance imaging (MRI) in patients with axial spondyloarthritis (axSpA) and to compare with the Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system. METHODS: From September 2013 to March 2022, patients with axSpA who underwent 3.0T SIJ-MRI were included and were randomly divided into training and validation cohorts at a ratio of 7:3. The optimal radiomics features selected from the SIJ-MRI in the training cohort were included to generate the radiomics model. The performance of the model was evaluated by ROC analysis and decision curve analysis (DCA). Rad scores were calculated using the radiomics model. The responsiveness was compared for Rad scores and SPARCC scores. We also assessed the correlation between the Rad score and SPARCC score. RESULTS: A total of 558 patients were finally included. The radiomics model showed favorable discrimination of a SPARCC score <2 or ≥2 both in the training (AUC, 0.90; 95% CI: 0.87-0.93) and validation cohorts (AUC, 0.90; 95% CI, 0.86-0.95). DCA confirmed that the model was clinically useful. Rad score showed higher responsiveness to treatment-related change than SPARCC score. Furthermore, a significant correlation was noted between the Rad score and SPARCC score when scoring the status of BMO (rs=0.80, P < 0.001), and a strong correlation was noted when scoring the change in BMO (r=0.70, P < 0.001). CONCLUSION: The study proposed a radiomics model to accurately quantify the BMO of SIJs in patients with axSpA, providing an alternative to the SPARCC scoring system. Key Points • The Rad score is an index with high validity for the objective and quantitative evaluation of bone marrow edema (BMO) of the sacroiliac joints in axial spondyloarthritis. • The Rad score is a promising tool to monitor the change of BMO upon treatment.

A predictive clinical-radiomics nomogram for diagnosing of axial spondyloarthritis using MRI and clinical risk factors.

OBJECTIVES: Construct and validate a nomogram model integrating the radiomics features and the clinical risk factors to differentiating axial spondyloarthritis (axSpA) in low back pain patients undergone sacroiliac joint (SIJ)-MRI. METHODS: A total of 638 patients confirmed as axSpA (n = 424) or non-axSpA (n = 214) who were randomly divided into training (n = 447) and validation cohorts (n = 191). Optimal radiomics signatures were constructed from the 3.0 T SIJ-MRI using maximum relevance-minimum redundancy (mRMR) and the least absolute shrinkage and selection operator (LASSO) algorithm in the training cohort. We also included six clinical risk predictors to build the clinical model. Incorporating the independent clinical factors and Rad-score, a nomogram model was constructed by multivariable logistic regression analysis. The performance of the clinical, Rad-score, and nomogram models were evaluated by ROC analysis, calibration curve and decision curve analysis (DCA). RESULTS: A total of 1316 features were extracted and reduced to 15 features to build the Rad-score. The Rad-score allowed a good discrimination in the training (AUC, 0.82; 95% CI: 0.77, 0.86) and the validation cohort (AUC, 0.82; 95% CI: 0.76, 0.88). The clinical-radiomics nomogram model also showed favourable discrimination in the training (AUC, 0.90; 95% CI: 0.86, 0.93) and the validation cohort (AUC, 0.90; 95% CI: 0.85, 0.94). Calibration curves (P >0.05) and DCA demonstrated the nomogram was useful for axSpA diagnosis in the clinical environment. CONCLUSION: The study proposed a radiomics model was able to separate axSpA and non-axSpA. The clinical-radiomics nomogram can increase the efficacy for differentiating axSpA, which might facilitate clinical decision-making process.

MRI compared with low-dose CT scanning in the diagnosis of axial spondyloarthritis.

OBJECTIVES: To compare the performance of conventional radiography, ldCT, and MRI in the diagnosis of sacroiliitis in suspected axial spondyloarthritis (axSpA). METHODS: Patients presenting with > 3 months chronic back pain were assessed by axSpA-experienced rheumatologists and diagnosed as axSpA or not; axSpA patients were then considered nr-axSpA or AS using plain radiography. Non-axSpA patients were recruited as controls, and divided into non-inflammatory and inflammatory groups on the basis of inflammatory back pain and/or CRP/ESR elevation. Clinical variables, pelvic radiography, sacroiliac joint (SIJ) ldCT, and SIJ MRI were obtained. RESULTS: A total of 121 patients were included and had SIJ radiography and ldCT, of whom 71 additionally had an SIJ MRI. These included 23 non-inflammatory controls, 21 inflammatory controls, 32 nr-axSpA cases, and 45 AS cases. Fourteen of 32 (44%) nr-axSpA patients had positive ldCT scans, 21/24 (88%) had MRI-BMO, and 11/24 (46%) had MRI-structural lesions. ldCT had high specificity with only 1/23 (4%) non-inflammatory controls being positive. MRI-BMO had the highest sensitivity for nr-axSpA, but compared with ldCT lower specificity, with 5/15 (33%) of non-inflammatory controls being positive, and similar sensitivity for AS (20/22 (91%) vs 44/44 for ldCT). CONCLUSIONS: ldCT identifies evidence of radiographic change in a significant proportion of nr-axSpA cases and is highly specific for axSpA. MRI-BMO lesions are more sensitive than either conventional radiography or MRI-structural assessment for axSpA. The relative position of these imaging modalities in screening for axSpA needs to be reconsidered, also taking into account the costs involved.Key Points• ldCT is more sensitive for erosions or sclerosis in axSpA than plain radiography, with 44% of patients with nr-axSpA having evidence of AS-related sacroiliac joint changes on ldCT.• MRI-structural lesions are no more sensitive but are less specific for AS than ldCT.• MRI-BMO is the most sensitive test for nr-axSpA of the modalities tested but is less specific for axSpA than for ldCT.

Farnesoid-X-receptor expression in monocrotaline-induced pulmonary arterial hypertension and right heart failure.

OBJECTIVE: The farnesoid-X-receptor (FXR) is a metabolic nuclear receptor superfamily member that is highly expressed in enterohepatic tissue and is also expressed in the cardiovascular system. Multiple nuclear receptors, including FXR, play a pivotal role in cardiovascular disease (CVD). Pulmonary arterial hypertension (PAH) is an untreatable cardiovascular system disease that leads to right heart failure (RHF). However, the potential physiological/pathological roles of FXR in PAH and RHF are unknown. We therefore compared FXR expression in the cardiovascular system in PAH, RHF and a control. METHODS AND RESULTS: Hemodynamic parameters and morphology were assessed in blank solution-exposed control, monocrotaline (MCT)-exposed PAH (4 weeks) and RHF (7 weeks) Sprague-Dawley rats. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR), Western blot (WB), immunohistochemistry (IHC) analysis and immunofluorescence (IF) analysis were performed to assess FXR levels in the lung and heart tissues of MCT-induced PAH and RHF rats. In normal rats, low FXR levels were detected in the heart, and nearly no FXR was expressed in rat lungs. However, FXR expression was significantly elevated in PAH and RHF rat lungs but reduced in PAH and RHF rat right ventricular (RV) tissues. FXR expression was reduced only in RHF rat left ventricular (LV) tissues. CONCLUSIONS: The differential expression of FXR in MCT-induced PAH lungs and heart tissues in parallel with PAH pathophysiological processes suggests that FXR contributes to PAH.

[The succession of sarcophagus beetles on carrion and its application in forensic medicine].

Sarcophagus beetles, which can not be replaced by Diptera, play a pivotal role not only in estimating PMI of dry human skeletal remains in the later stages decomposition of carcasses, but also the corruption, destruction, decomposition and posture changes of carcasses. This article explicates the succession of sarcophagus beetles on carrion and its influencing factors, and introduces the application and prospects of sarcophagus beetles in forensic entomology. Although few researches focus on sarcophagus beetles at present, it is believed that more and more forensic scientists will pay attention to sarcophagus beetles' application in forensic identification.