[A quantitative MRI comparative study of imaging markers for cerebral small vessel disease in the middle-aged and elderly patients with and without hypertension].

Objective: To explore the difference of MRI markers of small cerebral vascular disease in middle-aged and elderly patients with hypertension and non-hypertension. Methods: A cross-sectional study. The clinical data of 316 patients who underwent head MRI with susceptibility weighted imaging scans at the Affiliated Zhongda Hospital of Southeast University from November 2013 to August 2022 were retrospectively analyzed, including 190 males and 126 females, with the age of (71.6±8.9)years. According to the history of hypertension, the patients were divided into hypertension group(n=259) and the non-hypertension group(n=57). The patients in the non-hypertension group were further divided into abnormal blood pressure group on admission (n=19) and normal blood pressure group on admission (n=38). The imaging features of different CSVD dimensions in the patient's images were quantified or graded and compared between hypertensive and non-hypertensive patient groups. Deep learning methods were employed to segment white matter lesions, and voxel-wise analysis was conducted to investigate the differences in whole-brain white matter lesion probability between patients in both groups. Spearman correlation analysis was used to analyze the correlation between hypertension and small cerebral vascular disease. Results: Compared with the non-hypertensive group, the cerebral microhemorrhage count, deep microhemorrhage count, basal ganglia level lacunae count, perivascular space (EPVS) grade of hemioval center level and EPVS grade of basal ganglia level were higher in the hypertensive group (all P<0.05). The cerebral microhemorrhage count [3.0(1.0, 15.0) vs 1.0 (0, 4.2)], deep microhemorrhage count [1.0 (0, 7.0) vs 1.0 (0, 4.2)] and EPVS classification at basal ganglium level [2.0(1.0, 3.0) vs 1.0(1.0, 2.0)] in the group with history of hypertension were higher than those in the group with normal blood pressure at admission (all P<0.05). The EPVS grade at the central level of the semiovale in the hypertension group was higher than that of the group with normal blood pressure at admission [2.0(1.0, 2.0) vs 1.0 (1.0, 2.0)], and also higher than that of the group with abnormal blood pressure at admission [2.0(1.0, 2.0) vs 1.0(1.0, 2.0)](both P<0.05). Voxel-by-voxel analysis showed no significant difference in the probability of white matter lesions in the whole brain between patients with and without a history of hypertension, but patients with a history of hypertension showed more extensive para-ventricular white matter hypersignaling than those without a history of hypertension. Spearman correlation analysis showed that hypertension grade was correlated with the number of microbleeding lesions in depth (r=0.149), the number of lacunae lesions in the center of the hemioval (r=0.209), and the number of lacunae lesions in the basal ganglia (r=0.204) (all P<0.05). Conclusions: Chronic hypertension can affect different dimensions of small vessel disease imaging, primarily manifested in the increases of deep microbleed counts and the EPVS grade.

Multi-scale mechanical investigation of articular cartilage suffered progressive pseudorheumatoid dysplasia.

BACKGROUND: Progressive pseudorheumatoid dysplasia is a rare skeletal dysplasia mainly caused by abnormal autosomal recessive inheritance. Although the main function of cartilage is mechanical support and the characteristics of this disease is the degradation of AC, previous studies on it had been mainly focused on clinical and genetic aspects and the mechanical behavior of the cartilage affected by PPRD is still ambiguous. In this study, we investigate the mechanics and structure of the cartilage suffered disease at multi-scale, from individual chondrocytes to the bulk-scale tissue. METHODS: Depth-sensing indenter were employed to investigate the mechanics of cartilage; we performed atomic force microscope nanoindentation to investigate the cell mechanics and scanning electron microscopy were used to explore the structure feature and chemical composition. FINDINGS: The elastic modulus of chondrocytes harvested from cartilage suffered from progressive pseudorheumatoid dysplasia is significantly higher than from normal cartilage, same trend were also found in tissue level. Moreover, denser collagen meshwork and matrix calcification were also observed. INTERPRETATION: The elastic modulus of cartilage should closely related to its denser structure and the calcification, and may potentially be an indicator for clinical diagnosis. The stiffening of chondrocytes during PPRD progression should play a rather important role in its pathogenesis.