Background This study aimed to assess the validity and pathophysiology of the T2/FLAIR-mismatch sign for noninvasive identification of isocitrate dehydrogenase (IDH)-mutant 1p/19q non-codeleted glioma. Methods Magnetic resonance imaging scans from 408 consecutive patients with newly diagnosed glioma (113 lower-grade gliomas and 295 glioblastomas) were evaluated for the presence of T2/FLAIR-mismatch sign by 2 independent reviewers. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated to assess the performance of the T2/FLAIR-mismatch sign for identifying IDH-mutant 1p/19q non-codeleted tumors. An exploratory analysis of differences in contrast-enhancing tumor volumes, apparent diffusion coefficient (ADC) values, and relative cerebral blood volume (rCBV) values in IDH-mutant gliomas with versus without the presence of a T2/FLAIR-mismatch sign (as well as analysis of spatial differences within tumors with the presence of a T2/FLAIR-mismatch sign) was performed. Results The T2/FLAIR-mismatch sign was present in 12 cases with lower-grade glioma (10.6%), all of them being IDH-mutant 1p/19q non-codeleted tumors (sensitivity = 10.9%, specificity = 100%, PPV = 100%, NPV = 3.0%, accuracy = 13.3%). There was a substantial interrater agreement to identify the T2/FLAIR-mismatch sign (Cohen’s kappa = 0.75 [95% CI, 0.57–0.93]). The T2/FLAIR-mismatch sign was not identified in any other molecular subgroup, including IDH-mutant glioblastoma cases (n = 5). IDH-mutant gliomas with a T2/FLAIR-mismatch sign showed significantly higher ADC (P < .0001) and lower rCBV values (P = .0123) as compared to IDH-mutant gliomas without a T2/FLAIR-mismatch sign. Moreover, in IDH-mutant gliomas with T2/FLAIR-mismatch sign the ADC values were significantly lower in the FLAIR-hyperintense rim as compared to the FLAIR-hypointense core of the tumor (P = .0005). Conclusions This study confirms the high specificity of the T2/FLAIR-mismatch sign for noninvasive identification of IDH-mutant 1p/19q non-codeleted gliomas; however, sensitivity is low and applicability is limited to lower-grade gliomas. Whether the higher ADC and lower rCBV values in IDH-mutant gliomas with a T2/FLAIR-mismatch sign (as compared to those without) translate into a measurable prognostic effect requires investigation in future studies. Moreover, spatial differences in ADC values between the core and rim of tumors with a T2/FLAIR-mismatch sign potentially reflect specific distinctions in tumor cellularity and microenvironment.

Objetivo: Detectar las alteraciones estructurales de los músculos peniformes proximales en pacientes con diagnóstico de lupus eritematoso sistémico (LES) y describir su relación con la actividad de la enfermedad y tiempo de tratamiento. Métodos: Pacientes > 18 años con diagnóstico confirmado de LES atendidos durante el periodo comprendido entre enero de 2016 y septiembre de 2018. Se extrajeron de las historias clínicas datos demográficos, clínicos y serológicos previa realización de una ecografía musculoesquelética de los músculos peniformes proximales, tríceps y vasto lateral, para evaluar parámetros cualitativos y cuantitativos de la arquitectura muscular (grosor muscular, longitud del fascículo, ángulo de penación, ecogenicidad, atrofia y edema muscular). Resultados: Se incluyeron 21 pacientes de los cuales 18 eran mujeres (85,7 %), 19 de ellos en el rango de 18-50 años de edad (90,4 %), 15 refirieron mialgia en la entrevista (71 %) y 7 mostraron leve pérdida de la fuerza según la escala Medical Research Council (MRC) (33 %). La mayoría de pacientes recibió tratamiento a base de esteroides (95 %) más un medicamento modificador de la enfermedad. Diez pacientes tenían índice de actividad de la enfermedad leve a moderado (81,2 %). En cuanto a las medidas ecográficas, se encontró una relación significativa entre un ángulo de penación menor a 11,4 grados y atrofia muscular con valores de p = 0,035. Conclusiones: La ecografía musculoesquelética es un método no invasivo útil para la detección de cambios estructurales en la arquitectura muscular del músculo vasto lateral en pacientes con diagnóstico de LES.

OBJECTIVE To assess the validity and pathophysiology of the T2/FLAIR mismatch sign for non-invasive identification of IDH-mutant 1p/19q non-codeleted glioma. METHODS MRI scans from 408 consecutive patients with newly diagnosed glioma (113 lower-grade glioma and 295 glioblastoma) were evaluated for the presence of a T2/FLAIR-mismatch sign (defined as complete/near-complete hyperintense signal on T2w, simultaneous hypointense signal on FLAIR except for a hyperintense peripheral rim) by two independent reviewers. Sensitivity, specificity, accuracy, positive and negative predictive value (PPV, NPV) were calculated to assess the performance of the T2/FLAIR-mismatch sign for identifying IDH-mutant 1p/19q non-codeleted tumors. An exploratory analysis of spatial differences in ADC and rCBV values comparing the FLAIR-hypointense core vs. hyperintense rim in cases with presence of a T2/FLAIR-mismatch sign was performed. RESULTS There was substantial interrater agreement to identify the T2/FLAIR-mismatch sign (Cohen’s Kappa = 0.75 [95% CI 0.57–0.93]). The T2/FLAIR-mismatch sign was present in 12 cases with lower-grade glioma (10.6%), all of them were IDH-mutant, 1p/19q non-codeleted tumors (sensitivity=10.9%, specificity=100%, PPV=100%, NPV=3.0%, accuracy=13.3%). The T2/FLAIR-mismatch sign was not identified in any other molecular subgroup, especially not in any of the IDH-mutant glioblastoma cases (n=5). In tumors with T2/FLAIR-mismatch sign the ADC values were significantly lower in the rim as compared to the core (p=0.0005) whereas there was no difference in rCBV values (p=0.4258). CONCLUSION This study confirms the high specificity of the T2/FLAIR-mismatch sign for non-invasive identification of IDH-mutant 1p/19q non-codeleted gliomas, although sensitivity is low and applicability is limited to lower-grade gliomas. The identified spatial differences in ADC values between the core and rim of tumors with a T2/FLAIR-mismatch sign potentially reflects differences in tumor cellularity and microenvironment.

El cerebelo es un órgano motor ubicado en la fosa posterior, en estrecha relación con el tallo cerebral. Su función principal es ser auxiliar en el comienzo de los movimientos voluntarios así como la modulación de estos. Está compuesto por el vermis centralmente y los dos hemisferios cerebelosos laterales al vermis. Se encuentra irrigado principalmente por tres arterias: cerebelosa posteroinferior, cerebelosa anteroinferior y cerebelosa superior. El objetivo de este artículo es realizar una revisión de la anatomía funcional del cerebelo y su correlación en neuroimágenes.