The effect of regions-of-interest and elasticity modulus selection on differentiating benign and malignant cervical lymph nodes with shear wave elastography

OBJECTIVE: Imaging diagnosis of cervical lymphadenopathy has conventionally used ultrasonography. Shear wave elastography (SWE) is a recent ultrasound technological advancement that has shown promise in the important medical problem of differentiating between benign and malignant cervical lymph nodes based on quantitative measurements of elasticity modulus. However, widely varying elasticity modulus metrics and regions-of-interest (ROIs) were used in existing studies, leading to inconsistent findings and results that are hard to compare with each other. METHODS: Using a large dataset of 264 cervical lymph nodes from 200 patients, we designed a study comparing three elasticity modulus metrics (Emax, Emean, and standard deviation-SD) with three different ROIs to evaluate the effect of such selections. The metric values were compared between the benign and malignant node groups. The different ROI and metric selections were also compared through receiver operating characteristics curve analysis. RESULTS: For all ROIs, all metric values were significantly different between the two groups, indicting their diagnostic potential. This was confirmed by the ≥0.80 area under the curve (AUC) values achieved with these metrics. Different ROIs had no effect on Emax, whereas all ROIs achieved high performance at 0.88 AUC. For Emean, the smallest ROI focusing on the area of the highest elasticity achieved the best diagnostic performance. In contrast, the larger ROIs achieved higher performances for SD. CONCLUSIONS: This study illustrated the effect of elasticity modulus and ROI selection on the diagnostic performance of SWE on cervical lymphadenopathy. These new findings help guide relevant future studies and clinical applications of this important quantitative imaging modality.

Isolation and identification of Murine Cerebral Microglial Cells

Even though the brain has been considered to be an immunologically privileged organ, recent reports showed that certain cells of the brain may be involved in immunological process in the brain. For example, some cells of the brain can present antigen to T-lymphocytes, to express class II major histocompativility antigen, and secrete interleukin-1 and -3 molecules. In addition, they are capable to phagocytose particles and possess receptors for the Fc portion on IgG. In this study, the authors tried to isolate the microglial cells from new born mice and characterize them. The isolated cells could produce such reactive oxygen intermediates(ROIs) an superoxide and hydrogen peroxide that were measured by luminometer after amplification by lucigenin and luminol respectively and could secrete reactive nitrogen intermediates(RNIs), when the cells were incubated with r-IFN plus LPS. The cells could also ingest fluorescent particles and raise intracellular calcium after stimulation with agonists when measured by flow cytometer. Our data showed that the microglial cells of the brain may belong to a member of mononuclear phagocytic system(MPS) of the body that are responsible for the host defence against invading microorganisms.