Doppler ultrasonographic measurement of short-term effects of valsalva maneuver on retrobulbar blood flow

Neurodegenerative Disorders of the Eye and of the Brain: A Perspective on Their Fluid-Dynamical Connections and the Potential of Mechanism-Driven Modeling

Neurodegenerative disorders (NDD) such as Alzheimer's and Parkinson's diseases are significant causes of morbidity and mortality worldwide. The pathophysiology of NDD is still debated, and there is an urgent need to understand the mechanisms behind the onset and progression of these heterogenous diseases. The eye represents a unique window to the brain that can be easily assessed via non-invasive ocular imaging. As such, ocular measurements have been recently considered as potential sources of biomarkers for the early detection and management of NDD. However, the current use of ocular biomarkers in the clinical management of NDD patients is particularly challenging. Specifically, many ocular biomarkers are influenced by local and systemic factors that exhibit significant variation among individuals. In addition, there is a lack of methodology available for interpreting the outcomes of ocular examinations in NDD. Recently, mathematical modeling has emerged as an important tool capable of shedding light on the pathophysiology of multifactorial diseases and enhancing analysis and interpretation of clinical results. In this article, we review and discuss the clinical evidence of the relationship between NDD in the brain and in the eye and explore the potential use of mathematical modeling to facilitate NDD diagnosis and management based upon ocular biomarkers.

Comparison of three ultrasonographic examinations on the synovial membrane vascularity of RA patients

Rheumatoid arthritis (RA) is a systemic autoimmune disease involving multiple joints and often involves the small joints, and the lesions are symmetric, invasive, and disabling. Synovial blood flow in patients with RA was compared using color Doppler flow imaging (CDFI), power Doppler ultrasound (PDUS), and superb microvascular imaging (SMI) to determine the application value of SMI in synovial vasospasm of knee joints. The blood flow signals of the suprapatellar recess in the knee joints of 41 RA patients (49 knees) were measured prior to undergoing total knee arthroplasty (TKA), recorded, and graded by CDFI, PDUS, and SMI. The results of the three ultrasound examination methods were compared and analyzed. The SMI grading was compared with the pathologic grade of the synovial membrane. Forty-one patients underwent 49 TKAs. The display rate of the synovial blood flow signal was 93.9% in the CDFI model, 97.9% in the PDUS model, and 100% in the SMI model. There were statistically significant differences in the results between the three ultrasound examination methods (H_C = 11.84, P < 0.05). The consistency of the SMI and pathologic grades of synovial membranes was better than the other methods (kappa = 0.639, P < 0.05). Compared with CDFI and PDUS, the signal of synovia flow detected by SMI was significantly higher in RA patients. SMI classification had a better consistency with the pathologic grade, and SMI has application value in assessing the activity of RA.