ABSTRACT
Abstract Introduction To evaluate diagnostic accuracy of high-resolution ultrasonography in differentiation of benign and malignant thyroid nodules in comparison to results of guided fine needle aspiration cytology based on the Bayes rule. Objective To assess the validity of ultrasonography results of thyroid nodules in comparison to guided fine needle aspiration cytology findings. Methods This study was done on randomly chosen 80 patients presented with palpable thyroid nodules, undergone real-time sonographic evaluation of thyroid nodules to characterize features, internal consistency, margins, echotexture, calcification, peripheral lucent halo and vascularity. Ultrasonography guided fine needle aspiration cytology studies of thyroid nodules were done. Results Palpable thyroid nodules were highly prevalent in fourth and fifth decades of life with female-male ratio, 4:1. Solid internal consistency was demonstrated by 75% malignant nodules. Hypoechogenicity and intra-nodular micro-calcifications were observed in 92% malignant nodules; 83% malignant nodules had intra-nodular vascularity and absence of peripheral halo. The pre-test prevalence of malignant nodules in the targeted population was 17.5%. As type I error, 2.5% false-positive cases and as type II error, 5.0% false-negative cases were detected. Values of sensitivity and specificity of the ultrasonography test were 71.43 and 96.97%, respectively. Conclusion Malignant thyroid nodules demonstrated ultrasonography characteristics of hypoechoic texture, intra-nodular micro-calcifications, solid consistency, internal vascularity and absence of peripheral halo. The ultrasonography test has 92.5% diagnostic accuracy to differentiate malignant from benign lesions in comparison to the gold standard fine needle aspiration cytology test.
Resumo Introdução Avaliar a precisão diagnóstica da ultrassonografia de alta resolução na diferenciação de nódulos tireoidianos benignos e malignos em comparação com os resultados da citologia de aspiração por agulha fina baseada na regra de Bayes. Objetivo Avaliar a validade dos resultados da USG de nódulos da tireoide em comparação com os resultados obtidos por citologia de aspiração por agulha fina. Método Este estudo foi feito em 80 pacientes selecionados aleatoriamente, que apresentavam nódulos palpáveis da tireoide, submetidos à avaliação ultrassonográfica em tempo real de nódulos da tireoide para estabelecer características, consistência interna, margens, ecotextura, calcificação, halo lucente periférico e vascularização. Foram feitos estudos por citologia de aspiração por agulha fina guiados pela USG dos nódulos de tireoide. Resultados Nódulos palpáveis da tireoide foram altamente prevalentes na quarta e quinta décadas de vida com uma razão sexo feminino-masculino de 4:1. A consistência interna sólida foi demonstrada em 75% de nódulos malignos. Hipoecogenicidade e microcalcificações intranodulares foram observadas em 92% de nódulos malignos; 83% dos nódulos malignos apresentaram vascularidade intranodular e ausência de halo periférico. A prevalência pré-teste de nódulos malignos na população alvo foi de 17,5%. Como erro tipo I, houve 2,5% de casos falso-positivos e como erro tipo II, foram detectados 5,0% de casos falso-negativos. Os valores de sensibilidade e especificidade do exame por USG foram de 71,43 e 96,97%, respectivamente. Conclusão Nódulos malignos da tireoide mostraram características de textura hipoecoica, microcalcificações intranodulares, consistência sólida, vascularidade interna e ausência de halo periférico na USG. O exame por USG tem 92,5% de precisão diagnóstica para diferenciar lesões malignas de benignas em comparação com o padrão ouro da citologia de aspiração por agulha fina.
ABSTRACT
INTRODUCTION: To evaluate diagnostic accuracy of high-resolution ultrasonography in differentiation of benign and malignant thyroid nodules in comparison to results of guided fine needle aspiration cytology based on the Bayes rule. OBJECTIVE: To assess the validity of ultrasonography results of thyroid nodules in comparison to guided fine needle aspiration cytology findings. METHODS: This study was done on randomly chosen 80 patients presented with palpable thyroid nodules, undergone real-time sonographic evaluation of thyroid nodules to characterize features, internal consistency, margins, echotexture, calcification, peripheral lucent halo and vascularity. Ultrasonography guided fine needle aspiration cytology studies of thyroid nodules were done. RESULTS: Palpable thyroid nodules were highly prevalent in fourth and fifth decades of life with female-male ratio, 4:1. Solid internal consistency was demonstrated by 75% malignant nodules. Hypoechogenicity and intra-nodular micro-calcifications were observed in 92% malignant nodules; 83% malignant nodules had intra-nodular vascularity and absence of peripheral halo. The pre-test prevalence of malignant nodules in the targeted population was 17.5%. As type I error, 2.5% false-positive cases and as type II error, 5.0% false-negative cases were detected. Values of sensitivity and specificity of the ultrasonography test were 71.43 and 96.97%, respectively. CONCLUSION: Malignant thyroid nodules demonstrated ultrasonography characteristics of hypoechoic texture, intra-nodular micro-calcifications, solid consistency, internal vascularity and absence of peripheral halo. The ultrasonography test has 92.5% diagnostic accuracy to differentiate malignant from benign lesions in comparison to the gold standard fine needle aspiration cytology test.
ABSTRACT
Uniparental genetic markers, mitochondrial DNA (mtDNA) and Y chromosomal DNA, are widely used for the inference of human ancestry. However, the resolution of ancestral origins based on mtDNA haplotypes is limited by the fact that such haplotypes are often found to be distributed across wide geographical regions. We have addressed this issue here by combining two sources of ancestry information that have typically been considered separately: historical records regarding population origins and genetic information on mtDNA haplotypes. To combine these distinct data sources, we applied a Bayesian approach that considers historical records, in the form of prior probabilities, together with data on the geographical distribution of mtDNA haplotypes, formulated as likelihoods, to yield ancestry assignments from posterior probabilities. This combined evidence Bayesian approach to ancestry assignment was evaluated for its ability to accurately assign sub-continental African ancestral origins to Afro-Colombians based on their mtDNA haplotypes. We demonstrate that the incorporation of historical prior probabilities via this analytical framework can provide for substantially increased resolution in sub-continental African ancestry assignment for members of this population. In addition, a personalized approach to ancestry assignment that involves the tuning of priors to individual mtDNA haplotypes yields even greater resolution for individual ancestry assignment. Despite the fact that Colombia has a large population of Afro-descendants, the ancestry of this community has been understudied relative to populations with primarily European and Native American ancestry. Thus, the application of the kind of combined evidence approach developed here to the study of ancestry in the Afro-Colombian population has the potential to be impactful. The formal Bayesian analytical framework we propose for combining historical and genetic information also has the potential to be widely applied across various global populations and for different genetic markers.