RESUMEN
Objective: To present a detailed explanation on the processing of magnetic susceptibility weighted imaging (SWI), demonstrating the effects of echo time and sensitive mask on the differentiation between calcification and hemosiderin. Materials and Methods: Computed tomography and magnetic resonance (magnitude and phase) images of six patients (age range 41– 54 years; four men) were retrospectively selected. The SWI images processing was performed using the Matlab’s own routine. Results: Four out of the six patients showed calcifications at computed tomography images and their SWI images demonstrated hyperintense signal at the calcification regions. The other patients did not show any calcifications at computed tomography, and SWI revealed the presence of hemosiderin deposits with hypointense signal. Conclusion: The selection of echo time and of the mask may change all the information on SWI images, and compromise the diagnostic reliability. Amongst the possible masks, the authors highlight that the sigmoid mask allows for contrasting calcifications and hemosiderin on a single SWI image. .
Objetivo: Expor em detalhes o processamento da imagem ponderada em suscetibilidade magnética (susceptibility weighted imaging – SWI), destacando o efeito da escolha do tempo de eco e da máscara sensível à diferenciação de calcificação e hemossiderina simultaneamente. Materiais e Métodos: Imagens de tomografia computadorizada e por ressonância magnética (magnitude e fase) foram selecionadas, retrospectivamente, de seis pacientes (idades entre 41 e 54 anos; quatro homens). O processamento das imagens SWI foi realizado em rotina própria no programa Matlab. Resultados: Dos seis pacientes estudados, quatro apresentaram calcificações nas imagens de tomografia computadorizada. Nestes, as imagens SWI mostraram sinal hiperintenso para as regiões de calcificações. Os outros dois pacientes não apresentaram calcificações nas imagens de tomografia computadorizada e apresentaram depósito de hemossiderina com sinal hipointenso na imagem SWI. Conclusão: A escolha do tempo de eco e da máscara pode alterar toda a informação da imagem SWI e comprometer a confiabilidade diagnóstica. Dentre as possíveis máscaras, destacamos que a máscara sigmoide permite contrastar calcificação e hemossiderina em uma única imagem SWI. .
Asunto(s)
Animales , Ratones , Empalme Alternativo/genética , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteína de Unión al Tracto de Polipirimidina/genética , Tropomiosina/genética , Secuencia de Bases , Sitios de Unión , Cartilla de ADN , Exones , Vectores Genéticos , Ligandos , Sistemas de Lectura Abierta , Reacción en Cadena de la Polimerasa , Proteína de Unión al Tracto de Polipirimidina/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Represoras/metabolismo , TransfecciónRESUMEN
Sheldon-Hall syndrome (SHS) is a rare autosomal dominant, inherited arthrogryposis syndrome characterized by multiple congenital contractures of the distal limbs. To date, four genes that encode the skeletal muscle fiber complex have been confirmed as the causative genes. Mutations in MYH3 have been identified most frequently and few cases of SHS caused by TPM2 mutations have been reported worldwide. This report describes, for the first time, a Korean family with two generations of SHS resulting from a rare TPM2 mutation, p.R133W. The affected mother and daughter manifested typical facial features of SHS including a triangular face with downslanting palpebral fissures, small mouth, high arched palate, and prominent nasolabial folds, and showed camptodactyly of fingers and deformities of feet with congenital vertical tali. Generalized myopathy with relative sparing of the slow-twitch muscle fibers was also revealed by electromyography in the affected mother.