Imaging secondary neuronal degeneration.

OBJECTIVE: Distal nerve degeneration refers to the process of disintegration of a neuron or neuronal circuit as a consequence of distal damage. The end result of multiple etiologies, this finding is becoming common due to the increasing number of imaging tests done. This paper aims to define the different types of distal nerve damage, review the anatomy and function of the most commonly affected tracts, and illustrate distal nerve damage through diagrams and representative cases from routine practice. CONCLUSION: Knowing the distant response that can be expected according to the topography of a neuronal lesion is crucial to avoid diagnostic errors. Axonal degeneration and transsynaptic degeneration can be both antegrade and retrograde. Studies of cerebral metabolism, perfusion sequences, and diffusion sequences are showing increasingly earlier changes related to the same process; radiologists need to be aware of these changes.

Carretera perdida: imagen de la degeneración neuronal secundaria / Imaging secondary neuronal degeneration

Objetivo: La degeneración neuronal distal (DND) define el proceso de desintegración de una neurona o un circuito neuronal como consecuencia de una noxa localizada a distancia. Es un hallazgo frecuente debido al creciente número de realización de pruebas de imagen y a que refleja un desenlace común a múltiples etiologías. El objetivo de este artículo es definir los distintos tipos de daño neuronal a distancia, revisar la anatomía y función de los tractos más frecuentemente afectados e ilustrar la DND con esquemas y casos representativos de la práctica habitual. Conclusión: El conocimiento de la respuesta a distancia esperable según la topografía de una lesión neuronal es crucial para evitar errores diagnósticos. La degeneración axonal y transináptica puede ser tanto anterógrada como retrógrada. Los estudios de metabolismo cerebral, las secuencias de perfusión y de difusión muestran cambios cada vez más precoces del mismo proceso con los que debemos estar familiarizados.(AU

Objective: Distal nerve degeneration refers to the process of disintegration of a neuron or neuronal circuit as a consequence of distal damage. The end result of multiple etiologies, this finding is becoming common due to the increasing number of imaging tests done. This paper aims to define the different types of distal nerve damage, review the anatomy and function of the most commonly affected tracts, and illustrate distal nerve damage through diagrams and representative cases from routine practice. Conclusion: Knowing the distant response that can be expected according to the topography of a neuronal lesion is crucial to avoid diagnostic errors. Axonal degeneration and transsynaptic degeneration can be both antegrade and retrograde. Studies of cerebral metabolism, perfusion sequences, and diffusion sequences are showing increasingly earlier changes related to the same process; radiologists need to be aware of these changes.(AU)

Fractura lineal de cráneo en el lactante con traumatismo craneoencefálico leve: influencia de la tomografía computarizada en su manejo / Linear skull fracture in infants after mild traumatic brain injury: influence of computed tomography in management

INTRODUCCIÓN: El traumatismo craneoencefálico (TCE) constituye un motivo frecuente de consulta en urgencias pediátricas. La necesidad de intervención quirúrgica en pacientes menores de 2 años con TCE leve es mínima, pero los hallazgos intracraneales pueden influir en el manejo del paciente. El objetivo de este trabajo es valorar el impacto de la TC en el manejo de los niños menores de 2 años con TCE leve que presentan una fractura lineal de cráneo en la radiografía convencional. MATERIAL Y MÉTODOS: Estudio descriptivo y retrospectivo en el que se analizan las radiografías de cráneo practicadas a pacientes menores de 2 años que fueron atendidos en el área de urgencias de nuestro hospital de nivel terciario por TCE leve en un período de 4 años. RESULTADOS: Se realizaron 88 exploraciones de tomografía computarizada (TC) realizadas por sospecha de fractura lineal de cráneo en radiografía. Se confirmó la fractura en 74 de ellos (16% de falsos positivos). De los 74 niños con diagnóstico confirmado de fractura, la TC fue normal en el 92% de los estudios y mostró hallazgos intracraneales en 6 casos (8% de los casos con fractura). Dos casos requirieron ingreso superior a 2 días (2,7% de todos los casos con fractura) y en los 4 casos restantes la estancia hospitalaria no superó las 48 horas. En ningún caso se requirió cirugía. CONCLUSIÓN: No parece justificada la realización de una TC craneal de forma sistemática en niños menores de 2 años con TCE y bajo/intermedio riesgo de lesión intracraneal, incluso con fractura lineal de cráneo. En ausencia de factores de riesgo, proponemos individualizar el estudio de imagen basándose en el criterio clínico

INTRODUCTION: Traumatic brain injury (TBI) is a common reason for pediatric emergency room visits. Surgical intervention for mild TBI is rarely necessary in children aged <2 years, but the intracranial findings can influence the management of the patient. This paper aims to evaluate the impact of computed tomography (CT) in the management of children aged <2 years with mild TBI and linear skull fractures on plain-film X-rays. MATERIAL AND METHODS: This retrospective descriptive study analyzed skull X-rays obtained in children <2 years old attended for mild TBI in the emergency room of our tertiary hospital over a 4-year period. RESULTS: A total of 88 CT studies were done for suspicion of linear skull fractures on plain-film X-rays. Fractures were confirmed in 74, representing a false-positive rate of 16%. Of the 74 infants with confirmed fractures, intracranial CT findings were normal in 68 (92%) and abnormal in 6 (8%). Two patients (2.7% of all patients with confirmed fractures) required hospital stays longer than 2 days; the other four patients with abnormal intracranial findings were discharged within 48hours of admission. None of the cases required surgery. CONCLUSION: Systematic CT studies do not seem justified for all children aged <2 years with TBI and low/intermediate risk of intracranial lesions, even when they have linear skull fractures. In the absence of risk factors, we propose individualizing the imaging study based on clinical criteria

Linear skull fracture in infants after mild traumatic brain injury: influence of computed tomography in management. / Fractura lineal de cráneo en el lactante con traumatismo craneoencefálico leve: influencia de la tomografía computarizada en su manejo.

INTRODUCTION: Traumatic brain injury (TBI) is a common reason for pediatric emergency room visits. Surgical intervention for mild TBI is rarely necessary in children aged <2 years, but the intracranial findings can influence the management of the patient. This paper aims to evaluate the impact of computed tomography (CT) in the management of children aged <2 years with mild TBI and linear skull fractures on plain-film X-rays. MATERIAL AND METHODS: This retrospective descriptive study analyzed skull X-rays obtained in children <2 years old attended for mild TBI in the emergency room of our tertiary hospital over a 4-year period. RESULTS: A total of 88 CT studies were done for suspicion of linear skull fractures on plain-film X-rays. Fractures were confirmed in 74, representing a false-positive rate of 16%. Of the 74 infants with confirmed fractures, intracranial CT findings were normal in 68 (92%) and abnormal in 6 (8%). Two patients (2.7% of all patients with confirmed fractures) required hospital stays longer than 2 days; the other four patients with abnormal intracranial findings were discharged within 48hours of admission. None of the cases required surgery. CONCLUSION: Systematic CT studies do not seem justified for all children aged <2 years with TBI and low/intermediate risk of intracranial lesions, even when they have linear skull fractures. In the absence of risk factors, we propose individualizing the imaging study based on clinical criteria.

Descripción de un caso de leucoencefalopatía hipóxica tardía: una imagen característica / Report of a case of delayed posthypoxic leukoencephalopathy: a peculiar image

No disponible

Valoración del cerebelo fetal mediante resonancia magnética / Evaluation of the fetal cerebellum by magnetic resonance imaging

La valoración del cerebelo fetal debe realizarse siempre por protocolo en las ecografías realizadas durante la gestación. Diferentes motivos como limitaciones técnicas o hallazgos ecográficos poco concluyentes han convertido la sospecha de patología del cerebelo fetal en una de las indicaciones más frecuentes de resonancia magnética (RM) prenatal. Aunque la ecografía fetal es la técnica de imagen de elección para su valoración, la RM muestra con mayor detalle la anatomía de la fosa posterior y las anomalías del desarrollo del cerebelo fetal, lo que permite un diagnóstico prenatal más preciso. Describimos la anatomía normal del cerebelo fetal mediante RM, así como las diferentes patologías que afectan a su normal desarrollo, y revisamos la terminología más apropiada para definirla, su diagnóstico diferencial y el papel de la RM en la evaluación prenatal de la fosa posterior (AU)

Obstetric protocols dictate that the fetal cerebellum should always be assessed during sonograms during pregnancy. For various reasons, including technical limitations or inconclusive sonographic findings, suspicion of cerebellar abnormalities is one of the most common indications for prenatal magnetic resonance imaging (MRI). Although sonography is the imaging technique of choice to assess the cerebellum, MRI shows the anatomy of the posterior fossa and abnormalities in the development of the fetal cerebellum in greater detail and thus enables a more accurate prenatal diagnosis. We describe and illustrate the normal anatomy of the fetal cerebellum on MRI as well as the different diseases that can affect its development. Moreover, we review the most appropriate terminology to define developmental abnormalities, their differential diagnoses, and the role of MRI in the prenatal evaluation of the posterior fossa (AU)

Malformaciones del oído interno: una aproximación diagnóstica práctica / Inner ear malformations: a practical diagnostic approach

La hipoacusia neurosensorial pediátrica es una causa mayor de discapacidad. Pese a que solo en el 20-40% de los casos se identifica una malformación del oído interno, su detección es de vital importancia para el tratamiento de estos pacientes. En este artículo se repasan la anatomía y la embriogénesis del oído interno. Se valora el papel de la neuroimagen en la hipoacusia neurosensorial pediátrica y en el estudio preimplante coclear. Se destaca la necesidad de la utilización de un sistema universal de clasificación de las malformaciones del oído interno con implicaciones pronósticas y terapéuticas. Por último, se describen e ilustran de forma concisa los hallazgos radiológicos clave de cada tipo de malformación. La tomografía computarizada y la resonancia magnética desempeñan un papel crucial en la caracterización de las malformaciones del oído interno y permiten la valoración de las estructuras anatómicas que posibilitan la selección del tratamiento y del abordaje quirúrgico idóneos (AU)

Pediatric sensorineural hearing loss is a major cause of disability; although inner ear malformations account for only 20-40% of all cases, recognition and characterization will be vital for the proper management of these patients. In this article relevant anatomy and development of inner ear are surveyed. The role of neuroimaging in pediatric sensorineural hearing loss and cochlear preimplantation study are assessed. The need for a universal system of classification of inner ear malformations with therapeutic and prognostic implications is highlighted. And finally, the radiological findings of each type of malformation are concisely described and depicted. Computed tomography and magnetic resonance imaging play a crucial role in the characterization of inner ear malformations and allow the assessment of the anatomical structures that enable the selection of appropriate treatment and surgical approach (AU)

Evaluation of the fetal cerebellum by magnetic resonance imaging. / Valoración del cerebelo fetal mediante resonancia magnética.

Obstetric protocols dictate that the fetal cerebellum should always be assessed during sonograms during pregnancy. For various reasons, including technical limitations or inconclusive sonographic findings, suspicion of cerebellar abnormalities is one of the most common indications for prenatal magnetic resonance imaging (MRI). Although sonography is the imaging technique of choice to assess the cerebellum, MRI shows the anatomy of the posterior fossa and abnormalities in the development of the fetal cerebellum in greater detail and thus enables a more accurate prenatal diagnosis. We describe and illustrate the normal anatomy of the fetal cerebellum on MRI as well as the different diseases that can affect its development. Moreover, we review the most appropriate terminology to define developmental abnormalities, their differential diagnoses, and the role of MRI in the prenatal evaluation of the posterior fossa.

Valor de la resonancia magnética cerebral en fetos con sospecha ecográfica de agenesia del cuerpo calloso / Value of brain MRI when sonography raises suspicion of agenesis of the corpus callosum in fetuses

Objetivo. Valorar el papel de la resonancia magnética (RM) en los fetos con sospecha ecográfica de agenesia del cuerpo calloso (ACC) para confirmar el diagnóstico y detectar anomalías intracraneales asociadas. Material y métodos. Estudio observacional descriptivo y retrospectivo de las RM cerebrales realizadas a 78 fetos remitidos a nuestro centro entre enero de 2006 y diciembre de 2015 por sospecha de ACC. Dos especialistas en diagnóstico por imagen fetal revisaron las exploraciones para evaluar la presencia y la morfología del cuerpo calloso. En los casos de ACC se valoró el resto de la neuroanatomía fetal para determinar la presencia de anomalías asociadas. Se correlacionaron los hallazgos de imagen prenatales con la RM posnatal o con la necropsia, cuando estuvieron disponibles. Resultados. La RM diagnosticó de ACC 45 casos, de los que 12 fueron de tipo parcial (26,7%) y 33 completa (73,3%). Se detectaron anomalías asociadas en 28 casos (62,2%), siendo la más frecuente la ventriculomegalia (78,6%), seguida de las malformaciones corticales (53,6%) y las anomalías de la fosa posterior (25%) y de la línea media (10,7%). Conclusión. La RM fetal facilita el diagnóstico de la ACC y la detección de anomalías asociadas. Su realización es importante ante la sospecha ecográfica prenatal de ACC (AU)

Objective. To evaluate the role of magnetic resonance imaging (MRI) in fetuses with a previous sonographic suspicion of agenesis of the corpus callosum (ACC) to confirm the diagnosis and to detect associated intracranial anomalies. Material and methods. Single-center retrospective and descriptive observational study of the brain MRI performed in 78 fetuses with ACC sonographic suspicion between January 2006 and December 2015. Two experts in fetal imaging reviewed the MRI findings to evaluate the presence and morphology of the corpus callosum. When ACC was detected the whole fetal brain anatomy was thoroughly studied to determine the presence of associated anomalies. Prenatal MR imaging findings were compared to postnatal brain MRI or necropsy findings when available. Results. Fetal MRI diagnosed 45 cases of ACC, 12 were partial (26.7%) and 33 complete (73.3%). In 28 cases (62,2%) associated intracranial anomalies were identified. The most often abnormality was ventriculomegaly (78,6%), followed by cortical malformations (53,6%), posterior fossa (25%) and midline anomalies (10,7%). Conclusion. Fetal brain MRI has an important role in the diagnosis of ACC and detection of associated anomalies. To perform a fetal brain MRI is important in fetuses with sonographic suspicion of ACC (AU)

Value of brain MRI when sonography raises suspicion of agenesis of the corpus callosum in fetuses. / Valor de la resonancia magnética cerebral en fetos con sospecha ecográfica de agenesia del cuerpo calloso.

OBJECTIVE: To evaluate the role of magnetic resonance imaging (MRI) in fetuses with a previous sonographic suspicion of agenesis of the corpus callosum (ACC) to confirm the diagnosis and to detect associated intracranial anomalies. MATERIAL AND METHODS: Single-center retrospective and descriptive observational study of the brain MRI performed in 78 fetuses with ACC sonographic suspicion between January 2006 and December 2015. Two experts in fetal imaging reviewed the MRI findings to evaluate the presence and morphology of the corpus callosum. When ACC was detected the whole fetal brain anatomy was thoroughly studied to determine the presence of associated anomalies. Prenatal MR imaging findings were compared to postnatal brain MRI or necropsy findings when available. RESULTS: Fetal MRI diagnosed 45 cases of ACC, 12 were partial (26.7%) and 33 complete (73.3%). In 28 cases (62,2%) associated intracranial anomalies were identified. The most often abnormality was ventriculomegaly (78,6%), followed by cortical malformations (53,6%), posterior fossa (25%) and midline anomalies (10,7%). CONCLUSION: Fetal brain MRI has an important role in the diagnosis of ACC and detection of associated anomalies. To perform a fetal brain MRI is important in fetuses with sonographic suspicion of ACC.

El cerebro adicto: imagen de las complicaciones neurológicas por el consumo de drogas / The addicted brain: imaging neurological complications of recreational drug abuse

Las drogas constituyen un gran problema sociosanitario. Tradicionalmente, la neuroimagen ha tenido un papel secundario limitado a la detección de eventos vasculares agudos. En la actualidad, el radiólogo ha adquirido gran relevancia en el diagnóstico de las complicaciones neurológicas agudas y crónicas, debido al avance en el conocimiento de la enfermedad y al desarrollo de las técnicas de imagen morfológicas y funcionales. Las principales complicaciones son la patología neurovascular, la infección, los trastornos tóxico-metabólicos y la atrofia cerebral. La sintomatología inespecífica y la negación del consumo hacen que la implicación del radiólogo pueda resultar fundamental en la atención de estos pacientes. La neuroimagen permite detectar alteraciones precoces y plantear el diagnóstico etiológico ante patrones de afectación específicos. Nuestro objetivo es describir el patrón de consumo y el mecanismo fisiopatológico de las drogas con mayor repercusión neurológica, así como ilustrar las complicaciones cerebrales agudas y crónicas mediante técnicas de imagen convencional y funcional (AU)

Recreational drug abuse represents a serious public health problem. Neuroimaging traditionally played a secondary role in this scenario, where it was limited to detecting acute vascular events. However, thanks to advances in knowledge about disease and in morphological and functional imaging techniques, radiologists have now become very important in the diagnosis of acute and chronic neurological complications of recreational drug abuse. The main complications are neurovascular disease, infection, toxicometabolic disorders, and brain atrophy. The nonspecific symptoms and denial of abuse make the radiologist's involvement fundamental in the management of these patients. Neuroimaging makes it possible to detect early changes and to suggest an etiological diagnosis in cases with specific patterns of involvement. We aim to describe the pattern of abuse and the pathophysiological mechanisms of the drugs with the greatest neurological repercussions as well as to illustrate the depiction of the acute and chronic cerebral complications on conventional and functional imaging techniques (AU)

Inner ear malformations: a practical diagnostic approach. / Malformaciones del oído interno: una aproximación diagnóstica práctica.

Pediatric sensorineural hearing loss is a major cause of disability; although inner ear malformations account for only 20-40% of all cases, recognition and characterization will be vital for the proper management of these patients. In this article relevant anatomy and development of inner ear are surveyed. The role of neuroimaging in pediatric sensorineural hearing loss and cochlear preimplantation study are assessed. The need for a universal system of classification of inner ear malformations with therapeutic and prognostic implications is highlighted. And finally, the radiological findings of each type of malformation are concisely described and depicted. Computed tomography and magnetic resonance imaging play a crucial role in the characterization of inner ear malformations and allow the assessment of the anatomical structures that enable the selection of appropriate treatment and surgical approach.

The addicted brain: imaging neurological complications of recreational drug abuse. / El cerebro adicto: imagen de las complicaciones neurológicas por el consumo de drogas.

Recreational drug abuse represents a serious public health problem. Neuroimaging traditionally played a secondary role in this scenario, where it was limited to detecting acute vascular events. However, thanks to advances in knowledge about disease and in morphological and functional imaging techniques, radiologists have now become very important in the diagnosis of acute and chronic neurological complications of recreational drug abuse. The main complications are neurovascular disease, infection, toxicometabolic disorders, and brain atrophy. The nonspecific symptoms and denial of abuse make the radiologist's involvement fundamental in the management of these patients. Neuroimaging makes it possible to detect early changes and to suggest an etiological diagnosis in cases with specific patterns of involvement. We aim to describe the pattern of abuse and the pathophysiological mechanisms of the drugs with the greatest neurological repercussions as well as to illustrate the depiction of the acute and chronic cerebral complications on conventional and functional imaging techniques.

Tomografía computarizada fetal de baja dosis para diagnosticar displasias óseas / Low-dose computed tomography to diagnose fetal bone dysplasias

Presentamos un caso de displasia cleidocraneal diagnosticado en la semana 25 de gestación mediante tomografía computarizada (TC) de baja dosis fetal. La sospecha era de displasia ósea grave debido al percentil bajo en los huesos largos y la apariencia ecográfica de craneosinostosis. La TC no demostró alteraciones incompatibles con la vida. La dosis efectiva de la prueba fue de 5 mSv, dentro del rango recomendado para estas exploraciones. La TC de baja dosis fetal es una técnica emergente que permite estudiar estructuras óseas con precisión a partir del segundo trimestre de gestación. En España, es legalmente posible interrumpir el embarazo en caso de malformación grave del feto incluso si se sobrepasa la semana 22 de gestación. Por tanto, ante la sospecha de una displasia ósea grave, el radiólogo debe conocer las estrategias para disminuir la dosis manteniendo una calidad diagnóstica suficiente, y conocer las estructuras óseas que debe evaluar (AU)

We present a case of cleidocranial dysplasia diagnosed by low-dose fetal computed tomography (CT) in the 25th week of gestation. Severe bone dysplasia was suspected because of the fetus’ low percentile in long bones length and the appearance of craniosynostosis on sonography. CT found no abnormalities incompatible with life. The effective dose was 5 mSv, within the recommended range for this type of examination. Low-dose fetal CT is a new technique that makes precision study of the bony structures possible from the second trimester of pregnancy. In Spain, abortion is legal even after the 22nd week of gestation in cases of severe fetal malformations. Therefore, in cases in which severe bone dysplasia is suspected, radiologists must know the strategies for reducing the dose of radiation while maintaining sufficient diagnostic quality, and they must also know which bony structures to evaluate (AU)

Low-dose computed tomography to diagnose fetal bone dysplasias. / Tomografía computarizada fetal de baja dosis para diagnosticar displasias óseas.

We present a case of cleidocranial dysplasia diagnosed by low-dose fetal computed tomography (CT) in the 25th week of gestation. Severe bone dysplasia was suspected because of the fetus' low percentile in long bones length and the appearance of craniosynostosis on sonography. CT found no abnormalities incompatible with life. The effective dose was 5 mSv, within the recommended range for this type of examination. Low-dose fetal CT is a new technique that makes precision study of the bony structures possible from the second trimester of pregnancy. In Spain, abortion is legal even after the 22nd week of gestation in cases of severe fetal malformations. Therefore, in cases in which severe bone dysplasia is suspected, radiologists must know the strategies for reducing the dose of radiation while maintaining sufficient diagnostic quality, and they must also know which bony structures to evaluate.