Halo sign in fetal cytomegalovirus infection: cerebral imaging abnormalities and postmortem histopathology in 35 infected fetuses.

OBJECTIVE: To evaluate the correlation of periventricular echogenic halo (halo sign) with histopathological findings and its association with other brain imaging abnormalities in fetuses with cytomegalovirus (CMV) infection. METHODS: This was a retrospective study of fetuses diagnosed with severe CMV infection based on central nervous system (CNS) abnormalities seen on ultrasound, which had termination of pregnancy (TOP) or fetal demise at a single center from 2006 to 2021. All included cases had been evaluated by conventional complete fetal autopsy. A maternal-fetal medicine expert reanalyzed the images from the transabdominal and transvaginal neurosonography scans, blinded to the histological findings. The halo sign was defined as the presence of homogeneous periventricular echogenicity observed in all three fetal brain orthogonal planes (axial, parasagittal and coronal). Cases were classified according to whether the halo sign was the only CNS finding (isolated halo sign) or concomitant CNS anomalies were present (non-isolated halo sign). An expert fetal radiologist reanalyzed magnetic resonance imaging (MRI) examinations when available, blinded to the ultrasound and histological results. Hematoxylin-eosin-stained histologic slides were reviewed independently by two experienced pathologists blinded to the neuroimaging results. Ventriculitis was classified into four grades (Grades 0-3) according to the presence and extent of inflammation. Brain damage was categorized into two stages (Stage I, mild; Stage II, severe) according to the histopathological severity and progression of brain lesions. RESULTS: Thirty-five CMV-infected fetuses were included in the study, of which 25 were diagnosed in the second and 10 in the third trimester. One fetus underwent intrauterine demise and TOP was carried out in 34 cases. The halo sign was detected on ultrasound in 32 (91%) fetuses (23 in the second trimester and nine in the third), and it was an isolated sonographic finding in six of these cases, all in the second trimester. The median gestational age at ultrasound diagnosis of the halo sign was similar between fetuses in which this was an isolated and those in which it was a non-isolated CNS finding (22.6 vs 24.4 weeks; P = 0.10). In fetuses with a non-isolated halo sign, the severity of additional ultrasound findings was not associated with the trimester at diagnosis, except for microencephaly, which was more frequent in the second compared with the third trimester (10/18 (56%) vs 1/8 (13%); P = 0.04). With respect to histopathological findings, ventriculitis was observed in all fetuses with an isolated halo sign, but this was mild (Grade 1) in the majority of cases (4/6 (67%)). Extensive ventriculitis (Grade 2 or 3) was more frequent in fetuses with a non-isolated halo sign (21/26 (81%)) and those without a periventricular echogenic halo (2/3 (67%); P = 0.032). All fetuses with an isolated halo sign were classified as histopathological Stage I with no signs of brain calcifications, white-matter necrosis or cortical injury. On the other hand, 25/26 fetuses with a non-isolated halo sign and all three fetuses without a periventricular echogenic halo showed severe brain lesions and were categorized as histopathological Stage II. Among fetuses with a non-isolated halo, histological brain lesions did not progress with gestational age, although white-matter necrosis was more frequent, albeit non-significantly, in fetuses diagnosed in the second vs the third trimester (10/15 (67%) vs 3/11 (27%); P = 0.06). CONCLUSIONS: In CMV-infected fetuses, an isolated periventricular echogenic halo was observed only in the second trimester and was associated with mild ventriculitis without signs of white-matter calcifications or necrosis. When considering pregnancy continuation, detailed neurosonographic follow-up complemented by MRI examination in the early third trimester is indicated. The prognostic significance of the halo sign as an isolated finding is still to be determined. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Management of pediatric central nervous system emergencies: a review for general radiologists. / Manejo de los casos de urgencia del sistema nervioso central pediátricos para radiólogos generales.

TEACHING OBJECTIVES: To review the most common and most important diseases and disorders of the central nervous system (CNS) in pediatric emergencies, discussing the indications for different imaging tests in each context. DISCUSSION: In pediatric patients, acute neurologic symptoms (seizures, deteriorating level of consciousness, focal neurologic deficits, etc.) can appear in diverse clinical situations (trauma, child abuse, meningoencephalitis, ischemia…). It is important to decide on the most appropriate neuroimaging diagnostic algorithm for each situation and age group, as well as to know the signs of the most typical lesions that help us in the etiological differential diagnosis. Pediatric patients' increased vulnerability to ionizing radiation and the possible need for sedation in studies that require more time are factors that should be taken into account when indicating an imaging test. It is essential to weigh the risks and benefits for the patient and to avoid unnecessary studies.

[Neuroimaging of Langerhans cell histiocytosis in the central nervous system of children]. / Neuroimagen de la histiocitosis de células de Langerhans en el sistema nervioso central pediátrico.

Langerhans cell histiocytosis (LCH) is a rare disease characterized by the accumulation within tissues of anomalous dendritic cells similar to Langerhans cells. The clinical presentation varies, ranging from the appearance of a single bone lesion to multisystemic involvement. Central nervous system (CNS) involvement, manifesting as diabetes insipidus secondary to pituitary involvement, has been known since the original description of the disease. Two types of CNS lesions are currently differentiated. The first, pseudotumoral lesions with infiltration by Langerhans cells, most commonly manifests as pituitary infiltration. The second, described more recently, consists of neurodegenerative lesions of the CNS associated with neurologic deterioration. This second type of lesion constitutes a complication of the disease; however, there is no consensus about the cause of this complication. Our objective was to describe the radiologic manifestations of LCH in the CNS in pediatric patients.

[Magnetic resonance imaging in juvenile idiopathic arthritis: peculiarities of imaging children]. / Artritis idiopática juvenil, peculiaridades de la imagen en la edad pediátrica con especial interés en la resonancia magnética.

The term juvenile idiopathic arthritis (JIA) encompasses a heterogeneous group of arthritides with no known cause that begin before the age of 16 years and persist for at least 6 weeks. In recent decades, imaging techniques have acquired a fundamental role in the diagnosis and follow-up of JIA, owing to the unification of the different criteria for classification, which has strengthened the research in this field, and to the development of disease-modifying antirheumatic drugs. In this article, we briefly explain what JIA is. Moreover, we describe the role and limitations of plain-film radiography, ultrasonography, and magnetic resonance imaging (MRI). Finally, we review the MRI protocol and findings, and we comment on the differential diagnosis.

Survey about the current use of fetal MRI in Spain.

In June 2019 in Seville, at the first course in fetal MRI, endorsed by the Spanish Society of Medical Radiology (SERAM) and the Spanish Society of Pediatric Radiology (SERPE), the Spanish fetal MRI group was founded. To establish this group, a questionnaire was designed for radiologists dedicated to prenatal imaging in Spain and disseminated to the SERAM's members. The questions were related to the type of hospital, to MRI studies (magnetic field, gestational age, use of sedation, number of studies per year, proportion of fetal neuroimaging studies), and to teaching and research about fetal MRI. A total of 41 responses were received from radiologists in 25 provinces (88% working in public hospitals). Very few radiologists in Spain perform prenatal ultrasonography (7%) or prenatal CT. MRI is done in the second trimester (34%) or in the third trimester (44%). In 95% of centers, fetal brain MRI studies predominate. In 41% of the centers, studies can be done on 3 T MRI scanners. Maternal sedation is used in 17% of centers. The number of fetal MRI studies per year varies widely, being much higher in Barcelona and Madrid than in the rest of Spain.

Survey about the current use of fetal MRI in Spain. / Encuesta sobre la situación actual de la resonancia magnética fetal en España.

In June 2019 in Seville, at the first course in fetal MRI, endorsed by the Spanish Society of Medical Radiology (SERAM) and the Spanish Society of Pediatric Radiology (SERPE), the Spanish fetal MRI group was founded. To establish this group, a questionnaire was designed for radiologists dedicated to prenatal imaging in Spain and disseminated to the SERAM's members. The questions were related to the type of hospital, to MRI studies (magnetic field, gestational age, use of sedation, number of studies per year, proportion of fetal neuroimaging studies), and to teaching and research about fetal MRI. A total of 41 responses were received from radiologists in 25 provinces (88% working in public hospitals). Very few radiologists in Spain perform prenatal ultrasonography (7%) or prenatal CT. MRI is done in the second trimester (34%) or in the third trimester (44%). In 95% of centers, fetal brain MRI studies predominate. In 41% of the centers, studies can be done on 3 T MRI scanners. Maternal sedation is used in 17% of centers. The number of fetal MRI studies per year varies widely, being much higher in Barcelona and Madrid than in the rest of Spain.

[X-linked adrenoleukodystrophy with an atypical radiological pattern]. / Adrenoleucodistrofia ligada al X con patron radiologico atipico.

INTRODUCTION: X-linked adrenoleukodystrophy (X-ALD) is the most frequent peroxisomal disease. It is due to a mutation in the ABCD1 gene. The loss of functioning of ABCD1 triggers ineffective beta oxidation of very long-chain fatty acids, which gives rise to an accumulation of these fatty acids. The typical alteration revealed in neuroimaging scans in the cerebral form is symmetrical periventricular demyelination with posterior location. CASE REPORT: We report the case of a 10-year-old boy with right spastic hemiparesis and subacute cognitive impairment. Magnetic resonance imaging of the brain showed symmetrical involvement of the white matter in the left frontoparietotemporal region, and calcifications were observed in the computerised axial tomography scan. X-ALD was confirmed by means of the elevated levels of very long-chain fatty acids, and a pathogenic variant was found in the ABCD1 gene. CONCLUSIONS: Symmetrical demyelination with calcifications has rarely been reported in X-ALD, and these findings could delay diagnosis. This exceptional presentation should always be taken into consideration in children with subacute onset of motor symptoms and cognitive or behavioural regression.

TITLE: Adrenoleucodistrofia ligada al X con patron radiologico atipico.Introduccion. La adrenoleucodistrofia ligada al X (ALD-X) es la enfermedad peroxisomica mas frecuente. Se debe a una mutacion en el gen ABCD1. La perdida de la funcion de ABCD1 provoca una betaoxidacion inefectiva de los acidos grasos de cadena muy larga, lo que provoca la acumulacion de estos acidos grasos. La alteracion tipica en la neuroimagen en la forma cerebral es la desmielinizacion periventricular simetrica y de localizacion posterior. Caso clinico. Niño de 10 anos, con hemiparesia espastica derecha y deterioro cognitivo subagudo. La resonancia magnetica cerebral mostro afectacion asimetrica de la sustancia blanca en la region frontoparietotemporal izquierda, y en la tomografia axial computarizada se visualizaban calcificaciones. Se confirmo ALD-X mediante la elevacion de los niveles de acidos grasos de cadena muy larga, y se encontro una variante patogenica en el gen ABCD1. Conclusiones. La desmielinizacion asimetrica con calcificaciones raramente se ha descrito en la ALD-X, y estos hallazgos podrian retrasar el diagnostico. Esta presentacion excepcional se deberia considerar siempre en niños con inicio subagudo de sintomas motores y regresion cognitiva o del comportamiento.

[Spontaneous rupture of the spleen secondary to intrasplenic aneurysm]. / Rotura de bazo espontánea secundaria a aneurisma intraesplénico.

Spontaneous rupture of the spleen is an uncommon emergency that usually occurs in a spleen affected by hematologic, neoplastic, or infectious diseases or as a complication of acute or chronic pancreatitis. This condition requires early diagnosis and appropriate treatment. Intrasplenic aneurysms are rare and rupture of the spleen secondary to intrasplenic aneurysm is extremely rare. We present the imaging findings for a case of splenic rupture secondary to an intrasplenic aneurysm. The patient was treated by percutaneous embolization, with excellent results. We review the literature on this entity and its endovascular treatment.