Interobserver variability of ultrasound parameters in portal hypertension

The aim of this study was to assess interobserver agreement of ultrasound parameters for portal hypertension in hepatosplenic mansonic schistosomiasis. Spleen size, diameter of the portal, splenic and superior mesenteric veins and presence of thrombosis and cavernous transformation were determined by three radiologists in blinded and independent fashion in 30 patients. Interobserver agreement was measured by the kappa index and intraclass correlation coefficient. Interobserver agreement was considered substantial (ê = 0.714-0.795) for portal vein thrombosis and perfect (ê = 1) for cavernous transformation. Interobserver agreement measured by the intraclass correlation coefficient was excellent for longitudinal diameter of the spleen (r = 0.828-0.869) and splenic index (r = 0.816-0.905) and varied from fair to almost perfect for diameter of the portal (r = 0.622-0.675), splenic (r = 0.573-0.913) and superior mesenteric (r = 0.525-0.607) veins. According to the results, ultrasound is a highly reproducible method for the main morphological parameters of portal hypertension in schistosomiasis patients.

Quantificação do fluxo portal em indivíduos sadios: comparação entre ressonância magnética e ultra-som Doppler / Measurement of portal blood flow in healthy individuals: a comparison between magnetic resonance imaging and Doppler ultrasound

OBJETIVO: Avaliar a concordância entre a ultra-sonografia com Doppler e a ressonância magnética na quantificação do fluxo portal em indivíduos sadios, e avaliar a reprodutibilidade destes métodos diagnósticos. MATERIAIS E MÉTODOS: Foi realizado estudo prospectivo, transversal, observacional e autopareado, avaliando 20 voluntários sadios submetidos a mensuração do fluxo portal por meio de ultra-sonografia com Doppler e por ressonância magnética, executada por dois observadores independentes. Foram calculadas as concordâncias entre os métodos e entre os observadores utilizando-se o coeficiente de correlação intraclasses e o coeficiente de Pearson. RESULTADOS: A concordância entre os exames de ultra-sonografia com Doppler e de ressonância magnética foi baixa (coeficiente intraclasses: 1,9 por cento-18,2 por cento; coeficiente de Pearson: 0,1 por cento-13,7 por cento; p=0,565). Os valores da média de fluxo portal medido pela ultra-sonografia e pela ressonância magnética foram, respectivamente, de 0,768 l/min e 0,742 l/min. A quantificação do fluxo portal medida pela ultra-sonografia e pela ressonância magnética demonstrou, respectivamente, concordância interobservador regular (coeficiente intraclasses: 43,3 por cento; coeficiente de Pearson: 43,0 por cento) e concordância excelente (coeficiente intraclasses: 91,4 por cento; coeficiente de Pearson: 93,4 por cento). CONCLUSÃO: A ressonância magnética é um método confiável para quantificar o fluxo portal, mostrando melhor concordância interobservador do que a ultra-sonografia com Doppler. Os dois métodos apresentam baixa concordância entre si na quantificação do fluxo portal.

OBJECTIVE: To evaluate the inter-observer agreement between Doppler ultrasonography and magnetic resonance imaging in the quantification of portal blood flow in healthy individuals, as well as evaluating the reproducibility of both methods. MATERIALS AND METHODS: A prospective, transverse, observational and self-paired study was developed evaluating 20 healthy volunteers whose portal blood flow was measured by means of Doppler ultrasonography and magnetic resonance imaging performed by two independent observers. Interobserver and intermethod agreements were calculated using the intraclass and Pearson's correlation coefficients. RESULTS: The agreement between Doppler ultrasonography and magnetic resonance imaging was low (intraclass coefficient: 1.9 percent-18.2 percent; Pearson's coefficient: 0.1 percent-13.7 percent; p=0.565). Mean values for the portal blood flow measured by Doppler ultrasonography and magnetic resonance imaging were respectively 0.768 l/min and 0.742 l/min. Interobserver agreement for quantification of the portal blood flow by Doppler ultrasonography and magnetic resonance imaging was respectively reasonable (intraclass coefficient: 43.3 percent; Pearson's coefficient: 43.0 percent) and excellent (intraclass coefficient: 91.4 percent; Pearson's coefficient: 93.4 percent). CONCLUSION: In the present study, magnetic resonance imaging demonstrated to be a reliable method for quantifying the portal blood flow, with a higher interobserver agreement than Doppler ultrasonography. The intermethod agreement was low.