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.

Treatment with acarbose in severe hypoglycaemia due to late dumping syndrome / Tratamiento con acarbosa en la hipoglicemia severa debido al síndrome de dumping tardío

BACKGROUND: We present a case of recurrent loss of consciousness, which was finally accurately diagnosed as late dumping syndrome twelve years after subtotal gastrectomy and successfully treated with acarbose. A 66-year old lean male was found unconscious repeatedly within one year. Oral glucose tolerance tests performed before and after acarbose treatment verified the diagnosis of late dumping syndrome. Acarbose can be used as a successful treatment modality for reactive hypoglycaemia due to late dumping syndrome by influencing the release of hormone.

ANTECEDENTES: Presentamos un caso de pérdida recurrente de conciencia, que fue finalmente diagnosticado con precisión como síndrome de dumping tardío, doce años después de la gastrectomía subtotal, y tratado con éxito con acarbosa. Un hombre magro de 66 años de edad fue encontrado inconsciente repetidas veces en un año. Las pruebas orales de tolerancia a la glucosa realizadas antes y después del tratamiento con acarbosa verificaron el diagnóstico de síndrome de dumping tardío. La acarbosa puede utilizarse como una modalidad de tratamiento acertado para la hipoglicemia reactiva debido al síndrome de dumping tardío por la influencia en la liberación de hormonas.