ACCURACY OF ABBREVIATED PROTOCOL OF MAGNETIC RESONANCE CHOLANGIO-PANCREATOGRAPHY IN THE DIAGNOSIS OF CHOLEDOCHOLITHIASIS.

BACKGROUND: Abbreviated magnetic resonance imaging protocols have emerged to reduce the examination time of the long protocols eliminating unnecessary pulse sequences to answer a targeted clinical question, without compromising diagnostic information. OBJECTIVE: The objective of this study was to evaluate the diagnostic accuracy of an abbreviated magnetic resonance cholangiopancreatography (A-MRCP) protocol in patients with suspected choledocholithiasis. METHODS: This retrospective study evaluated patients (ages 10 + years) that performed consecutive MRCP examination from October 2019 to June 2020, with the clinical suspicion of choledocholithiasis. Readers first evaluated the biliary tree using a four-sequence A-MRCP protocol and later reviewed the entire conventional eleven-sequence MRCP. Presence of choledocholithiasis, stone size, common bile duct caliber, and additional findings were evaluated. RESULTS: A total of 148 patients with MRCP were included (62.8% female, mean 50.9 years). The prevalence of choledocholithiasis was 32.2%. The accuracy of the abbreviated MRCP protocol for choledocholithiasis was 98.7%. There was no difference between the performance of the abbreviated and conventional MRCP image sets for detection of choledocholithiasis (kappa=0.970), with a sensitivity of 98% and a specificity of 99%. There was excellent inter-reader agreement evaluating for choledocholithiasis on both imaging sets of MRCP protocols (kappa values were 0.970). CONCLUSION: An abbreviated MRCP protocol to evaluate for choledocholithiasis provides similar diagnostic over the conventional MRCP protocol, offering potential for decreased scanning time and improved patient tolerability.

Acurácia do protocolo abreviado de colangioressonância magnética no diagnóstico de coledocolitíase / Accuracy of abbreviated protocol of magnetic resonance cholangio-pancreatography in the diagnosis of choledocholithiasis

ABSTRACT Background: Abbreviated magnetic resonance imaging protocols have emerged to reduce the examination time of the long protocols eliminating unnecessary pulse sequences to answer a targeted clinical question, without compromising diagnostic information. Objective: The objective of this study was to evaluate the diagnostic accuracy of an abbreviated magnetic resonance cholangiopancreatography (A-MRCP) protocol in patients with suspected choledocholithiasis. Methods: This retrospective study evaluated patients (ages 10 + years) that performed consecutive MRCP examination from October 2019 to June 2020, with the clinical suspicion of choledocholithiasis. Readers first evaluated the biliary tree using a four-sequence A-MRCP protocol and later reviewed the entire conventional eleven-sequence MRCP. Presence of choledocholithiasis, stone size, common bile duct caliber, and additional findings were evaluated. Results: A total of 148 patients with MRCP were included (62.8% female, mean 50.9 years). The prevalence of choledocholithiasis was 32.2%. The accuracy of the abbreviated MRCP protocol for choledocholithiasis was 98.7%. There was no difference between the performance of the abbreviated and conventional MRCP image sets for detection of choledocholithiasis (kappa=0.970), with a sensitivity of 98% and a specificity of 99%. There was excellent inter-reader agreement evaluating for choledocholithiasis on both imaging sets of MRCP protocols (kappa values were 0.970). Conclusion: An abbreviated MRCP protocol to evaluate for choledocholithiasis provides similar diagnostic over the conventional MRCP protocol, offering potential for decreased scanning time and improved patient tolerability.

RESUMO Contexto: Protocolos abreviados de ressonância magnética (RM) surgiram a fim de reduzir o tempo de exame, eliminando sequências de pulso desnecessárias para responder a uma questão clínica específica, sem comprometer o diagnóstico. Objetivo: O objetivo do estudo foi avaliar a acurácia diagnóstica de um protocolo abreviado de colangiopancreatografia por ressonância magnética (colangioRM) em pacientes com suspeita de coledocolitíase. Métodos Estudo retrospectivo, com pacientes acima de 10 anos que realizaram exame de colangioRM, entre outubro de 2019 a junho de 2020, com suspeita clínica de coledocolitíase. Os observadores, radiologistas especialistas, primeiro avaliaram a árvore biliar usando um protocolo abreviado de colangioRM composto por quatro sequências de pulso e, posteriormente, revisaram o protocolo convencional de colangioRM de 11 sequências. A presença de coledocolitíase, o tamanho do cálculo, o calibre do ducto hepático comum e achados adicionais foram avaliados. Resultados Um total de 148 pacientes foram incluídos, sendo 62,8% do sexo feminino, com média de 50,9 anos de idade. A prevalência de coledocolitíase foi de 32,2%. A acurácia do protocolo abreviado de colangioRM para coledocolitíase foi de 98,7%. Não houve diferença entre o desempenho dos protocolos abreviado e convencional de colangioRM para a detecção de coledocolitíase (k=0,970), com uma sensibilidade de 98% e uma especificidade de 99%. Além disso, observou-se excelente concordância entre observadores na avaliação de coledocolitíase em ambos os protocolos de colangioRM (k=0,925). Conclusão O protocolo abreviado de colangioRM apresentou excelente acurácia para o diagnóstico de coledocolitíase quando comparado ao protocolo convencional.