RESUMEN

Objetivo. Determinar el papel de la resonancia magnética (RM) cerebral en fetos que presentan ventriculomegalia aislada (VMA) en la evaluación ecográfica del cerebro fetal. Métodos. Se evaluaron retrospectivamente los hallazgos por ecografía y RM de 197 fetos diagnosticados con VMA entre noviembre de 2018 y noviembre de 2020. Se excluyeron los fetos con cariotipos anormales, anomalías adicionales o etiologías relacionadas a ventriculomegalia. Se comparó los resultados de ecografía y RM tanto en términos de medidas ventriculares medias como de grado de VMA. Resultados. Las mediciones de la RM fueron significativamente mayores en la VMA leve (10,33±0,38 mm frente a 11,11±0,51 mm, p<0,001) en comparación con la ecografía. En la VMA leve, la RM midió los ventrículos más anchos que la ecografía, con una diferencia media de 0,78 mm. No hubo diferencias significativas en las mediciones por ecografía y RM en cuanto a los valores medios de la VMA moderada y grave. Hubo buena concordancia entre la ecografía y la RM en la detección de la gravedad de la VMA derecha, izquierda y la media (Κ=0,265, Κ=0,324 y Κ=0,261, respectivamente). Los análisis de regresión lineal revelaron una relación estadísticamente significativa entre las mediciones de ecografía y RM de la VMA derecha, izquierda y la media (p<0,001, p<0,001 y p<0,001, respectivamente). La RM mostró una concordancia perfecta con la ecografía en detectar la lateralidad de la VMA (Κ=1,0, p<0,001). Conclusiones. En fetos con VMA leve detectada por ecografía se debe considerar la evaluación por RM del cerebro fetal para un diagnóstico preciso. Este enfoque puede proporcionar una estrategia eficaz en el manejo prenatal y el asesoramiento de estos embarazos.

Objective: To assess the role of brain magnetic resonance imaging (MRI) in fetuses presenting with isolated ventriculomegaly (IVM) in the ultrasound (US) evaluation of the fetal brain. Methods: US and MRI findings of 197 fetuses diagnosed with IVM between November 2018 and November 2020 were retrospectively evaluated. Fetuses with abnormal karyotypes, additional anomalies, or known etiologies for ventriculomegaly were excluded. US and MRI findings were compared both in terms of mean ventricular measurements and IVM grade. Results: MRI measurements were significantly higher in mild IMV (10.33 ± 0.38 mm vs. 11.11 ± 0.51 mm, p< 0.001) compared to US. In mild IVM, MRI measured ventricles larger than US with a mean difference of 0.78 mm. There was no significant difference in US and MRI measurements in terms of mean values in moderate and severe IVM. There was good agreement between US and MRI in detecting right, left and mean IVM severity (Κ=0.265, Κ=0.324, and Κ=0.261, respectively). Linear regression analyses revealed a statistically significant relationship between US and MRI measurements of the right, left, and mean IVM (p<0.001, p<0.001, and p<0.001, respectively). MRI showed perfect agreement with US in detecting IVM laterality (Κ=1.0, p<0.001). Conclusions: In fetuses with mild IVM detected by US, fetal brain MRI evaluation should be considered for accurate diagnosis. This approach may provide effective strategies in the antenatal management and counseling of these pregnancies.

RESUMEN

Medulloblastoma is the most common malignant solid tumor in childhood and the most common embryonal neuroepithelial tumor of the central nervous system. Several morphological variants are recognized: classic medulloblastoma, large cell/anaplastic medulloblastoma, desmoplastic/nodular medulloblastoma, and medulloblastoma with extensive nodularity. Recent advances in transcriptome and methylome profiling of these tumors led to a molecular classification that includes 4 major genetically defined groups. Accordingly, the 2016 revision of the World Health Organization's Classification of Tumors of the Central Nervous System recognizes the following medulloblastoma entities: Wingless (WNT)-activated, Sonic hedgehog (SHH)-activated, Group 3, and Group 4. This transcriptionally driven classification constitutes the basis of new risk stratification schemes applied to current therapeutic clinical trials. Because additional layers of molecular tumor heterogeneities are being progressively unveiled, several clinically relevant subgroups within the 4 major groups have already been identified. The purpose of this article is to review the recent basic science and clinical advances in the understanding of "medulloblastomas," and their diagnostic imaging correlates and the implications of those on current neuroimaging practice.

Asunto(s)

RESUMEN

OBJECTIVE: Intraosseous lipomas may be less rare lesions than previously suggested in the literature. They have frequently been misdiagnosed as other benign bone lesions. A combination of computed tomography, magnetic resonance imaging and radiography is essential for decreasing misdiagnosis rates. MATERIALS AND METHODS: This retrospective study presents ten cases of intraosseous lipoma. The patients' ages ranged from 25 to 80 years, and six of them were female. Six patients presented with bone pain, whereas four patients were asymptomatic with incidentally discovered lesions. The involved bones were: femur (four patients), tibia (two patients), calcaneus (one patient), sacrum (one patient), iliac bone (one patient), navicular bone (one patient). All of the patients were assessed by means of conventional radiography, computed tomography and magnetic resonance imaging of the affected region. RESULTS: In all of the cases, plain films revealed well-defined lytic lesions. Both computed tomography and magnetic resonance imaging were quite useful in demonstrating fat within the femur. The histologic pattern of all tumors was that of mature adipose tissue. CONCLUSION: Intraosseous lipoma is a well-defined entity that may develop with varying presentations. Plain radiographs alone cannot establish the diagnosis of this lesion. However, both computed tomography and magnetic resonance imaging are quite useful methods in these cases.

OBJETIVO: Lipomas intra-ósseos podem ser lesões menos raras do que anteriormente sugerido na literatura. Freqüentemente têm sido erroneamente diagnosticados como outras lesões ósseas benignas. A combinação de tomografia computadorizada, ressonância magnética e radiografia é essencial para reduzir as taxas de erro diagnóstico. MATERIAIS E MÉTODOS: Este estudo retrospectivo apresenta dez casos de lipoma intra-ósseo. As idades dos pacientes variavam entre 25 e 80 anos, e seis deles eram do sexo feminino. Seis pacientes apresentavam dor óssea, enquanto quatro eram assintomáticos com lesões descobertas casualmente. Os ossos afetados foram: fêmur (quatro pacientes), tíbia (dois pacientes), calcâneo (um paciente), sacro (um paciente), osso ilíaco (um paciente), osso navicular (um paciente). Todos os pacientes foram avaliados por meio de radiografia convencional, tomografia computadorizada e ressonância magnética das regiões afetadas. RESULTADOS: Em todos os casos, as radiografias revelaram lesões líticas bem delimitadas. Tanto a tomografia computadorizada como a ressonância magnética foram bastante úteis para demonstrar gordura dentro do tumor. O padrão histológico de todos os tumores caracterizou-se por tecido adiposo maduro. CONCLUSÃO: Lipoma intra-ósseo é uma entidade bem definida que pode se desenvolver com variadas apresentações. Radiografias convencionais, isoladamente, não podem diagnosticar essas lesões. Entretanto, a tomografia computadorizada e a ressonância magnética são métodos bastante úteis nesses casos.

Asunto(s)