The Role of Apparent Diffusion Coefficient Values in Glioblastoma: Differentiating Tumor Progression Versus Treatment-Related Changes.

OBJECTIVE: Glioblastoma represents the most common primary brain malignancy with a median survival of 15 months. Follow-up examinations are crucial to establish the presence of tumor recurrence, as well as treatment-associated changes such as ischemic infarction and radiation effects. Even though magnetic resonance imaging is a valuable tool, a histopathological diagnosis is often required because of imaging overlap between tumor recurrence and treatment associated changes. We set out to measure the apparent diffusion coefficient (ADC) values of the lesions in magnetic resonance imaging scans of treated glioblastoma patients to investigate if ADC values could accurately differentiate between tumor progression, radiation-related changes, and ischemic infarctions. METHODS: We evaluated ADC values among 3 groups, patients with tumor progression, radiation necrosis, and ischemic infarctions. The regions of interest were placed in the areas of greatest hypointensity among solid lesions using the ADC maps, excluding areas with necrotic, cystic, or hemorrhagic changes. The ADC values of the contralateral normal appearing white matter were also measured as the reference value for each patient. The relative ADC (rADC) values were measured for all 3 groups. Comparison between lesions and normal white matter was evaluated by Wilcoxon signed test. RESULTS: A total of 157 patients were included in the study; 49 patients classified as tumor progression, 58 patients as radiation necrosis, and 50 patients as ischemic infarctions. The mean ± SD ADC value was 752.8 ± 132.5 for tumor progression, 479.0 ± 105.2 for radiation-related changes, and 250.1 ± 57.2 for ischemic infarctions. The mean ± SD rADC value was 1.07 ± 0.22 for tumor progression, 0.66 ± 0.14 for radiation necrosis, and 0.34 ± 0.08 for ischemic infarctions. The mean rADC values were significantly higher in tumor progression, compared with both radiation necrosis and ischemic changes ( P < 0.001). CONCLUSIONS: The present study demonstrates that ADC values are a helpful tool to differentiate between tumor progression, radiation necrosis, and posttreatment ischemic changes.

Development of a Standardized Grading Scale for Atherosclerotic Disease of the Head and Neck.

OBJECTIVE: For research and risk factor analysis, a reproducible method quantifying atherosclerosis is necessary. Our aim was to develop a computed tomography (CT) angiography grading system to quantify atherosclerotic disease of the head and neck. METHODS: Institutional review board-approved, retrospective analysis was performed on 152 patients who underwent head/neck CT angiography. A grading scale was designed to calculate plaque burden at multiple sites with the sum referred to as atherosclerosis score. Three radiologists calculated scores with an overlap of cases to calculate the intraclass correlation coefficient. RESULTS: Without any prior training, the intraclass correlation coefficient between readers was considered fair. After a short tutorial, intraclass correlation coefficient was recalculated using separate patients, showing excellent correlation.Statistically significant positive correlation was found between atherosclerosis scale and age, hyperlipidemia, hypertension, and diabetes, but no correlation with sex or smoking status. CONCLUSIONS: A simple, visual grading scale for atherosclerosis in head/neck CT angiography was used to standardize reporting and better characterize a patient's risk of stroke.

Vertebral anomalies and VACTERL association in pontine tegmental cap dysplasia: a paediatric case report.

This case report highlights vertebral segmental anomalies and the fact that the child presented has a rare neurologic condition called pontine tegmental cap dysplasia. Additionally, this case aims to educate learners in developing a differential diagnosis for vertebral and cardiac anomalies such as VACTERL syndromes and common syndromes associated with butterfly vertebrae in children and adolescents.

Uncovering the Dorsal Thalamo-hypothalamic Tract of the Human Limbic System.

As a non-limbic structure, the human thalamus is the most important modulator of the limbic system. The hypothalamus plays vital roles in the survival of species by regulating fear, learning, feeding behavior, circadian rhythm, sociosexual and reproductive activities of the limbic system through connections with the thalamus. The detailed anatomy of the pathways responsible for mediating these responses, however, is yet to be determined. The mammillothalamic tract is known as the major direct thalamo-hypothalamic connection in the primates including the human brain connecting the ventral thalamus to the dorsal hypothalamus. Multiple dissection animal studies revealed additional connections specially from the dorsal thalamus to the ventral hypothalamic nuclei. Diffusion weighted imaging may be helpful in better visualizing the surgical anatomy of this additional connectivity noninvasively. This study aimed to investigate the utility of high spatial and high angular resolution diffusion weighted tractography technique for mapping the trajectory of this dorsal thalamic connectivity with the ventral hypothalamus in the human brain. We studied 30 healthy human subjects. Using a high-resolution diffusion weighted tractography technique, for the first time, we were able to delineate and reconstruct the trajectory of the dorsal thalamo-hypothalamic tract (DTH). We further revealed the close relationship of the DTH, fornix and hippocampus in healthy adult human brain.

Enfermedad de Rosai-Dorfman (ERD) con compromiso exclusivo del sistema nervioso central. Presentación de caso y revisión de literatura / Rosai-Dorfman Disease (RDD) With Isolated Compromise of the Central Nervous System. Case Report and Literature Review

La enfermedad de Rosai-Dorfman (ERD) o histiocitosis sinusal con linfadenopatía masiva (HSLM) es una entidad histiocítica benigna rara, que usualmente afecta los ganglios linfáticos. Se han descrito algunos casos en el sistema nervioso central, y son excepcionales los que aparecen sin afección nodular concomitante. La falta de patrones imaginológicos cerebrales típicos puede llevar a una cirugía por un diagnóstico erróneo, con causas atribuidas a un probable origen maligno. Usualmente, el diagnóstico histopatológico se realiza después del procedimiento quirúrgico. Esta entidad clínico-patológica carece de consenso en diagnóstico, curso clínico y tratamiento. Se presenta un caso de ERD con extensión intracraneal, con la lectura retrospectiva de los estudios imaginológicos.

Rosai-Dorfman Disease (RDD) or Sinus Histiocytosis with Massive Lymphadenopathy (SHML) is a rare benign histiocytic disorder, usually affecting the lymph nodes. Intracranial involvement is an uncommon variant of the disease; however, intracranial lesions without concomitant nodular involvement is exceptional. The lack of typical brain imaging patterns can lead to surgery due to misdiagnosis, with causes attributed to a probable malignant origin. Histopathological diagnosis is usually made after the surgical procedure. There is no consensus related to diagnosis, clinical course and treatment of this disease. A case report is presented on isolated intracranial RDD, with a retrospective reading of the imaging studies.

Neumomediastino espontáneo / Spontaneous Pneumomediastinum

El neumomediastino espontáneo (NME) es una patología infrecuente que consiste en la presencia de aire libre en los tejidos blandos del mediastino sin evidencia de lesión de la vía aérea o digestiva subyacente, y sin antecedente de procedimiento médico previo que lo explique. Esta entidad afecta con mayor frecuencia a hombres jóvenes, es de comportamiento benigno y generalmente es autolimitada. En el artículo se presenta el caso de un joven de 21 años de edad que presenta un neumomediastino espontáneo. Se hace luego una breve revisión de la literatura acerca de la epidemiología, la fisiopatología, las características clínicas y los hallazgos imaginológicos de esta entidad.

Spontaneous pneumomediastinum (SPM) is an uncommon condition characterized by the presence of free air in the soft tissues of the mediastinum without evidence of underlying injury in the airway or esophagus, or a history of prior medical procedure. This condition most often affects young men, it is usually benign and self-limited. In this paper we present the case of a 21-year-old man who presents a spontaneous pneumomediastinum, then we are going to perform a brief review of the literature regarding the epidemiology, pathophysiology, clinical features and imaging findings in this entity.

Síndrome de calcificación cerebral asociado a hipoparatiroidismo / Cerebral calcification syndrome associated with hypoparathyroidism

Las calcificaciones cerebrales agrupan diversas entidades patológicas que frecuentemente han sido referidas como enfermedad de Fahr. Estas tienen una presentación clínica variada, desde el curso subclínico hasta manifestaciones motoras convulsivas e inclusive demenciales. Se presenta el caso de una mujer de 46 años con una crisis epiléptica convulsiva generalizada, asociada a calcificaciones difusas por hipoparatiroidismo postquirúrgico, en quien se inicia reposición de calcio, logrando resolución del cuadro convulsivo. Este reporte destaca el abordaje fisiopatológico de las calcificaciones cerebrales por hipoparatiroidismo, la importancia de una definición más general de cómo sería el síndrome de calcificación cerebral teniendo en cuenta las diferentes entidades patológicas conocidas asociadas con diferente espectro clínico y, por último, pone en evidencia la carencia de investigaciones sobre el tema.

Brain calcifications group diverse pathological entities that have often been referred to as Fahr disease. These have a clinical presentation which varies from subclinical course to several motor manifestations and dementia. We report the case of a 46 year old woman with generalized seizures associated with diffuse calcifications on postoperative hypoparathyroidism in whom calcium supplementation starts achieving resolution of the symptoms. This report highlights the pathophysiological approach by hypoparathyroidism brain calcifications, the importance of a general definition as in the brain calcification syndrome considering different known disease entities associated with different clinical spectrum and, finally, demonstrates the lack of research on the subject.

Apendicitis aguda: Hallazgos radiológicos y enfoque actual de las imágenes diagnósticas / Acute appendicitis: Imaging Findings and current approach to diagnostic imaging

La apendicitis aguda es la causa más frecuente de dolor abdominal agudo que requiere cirugía. Antes de la aparición de las modernas técnicas en imágenes diagnósticas, el diagnóstico de apendicitis aguda era exclusivamente clínico; sin embargo, después de la introducción de imágenes seccionales como la tomografía computarizada, la resonancia magnética y la ultrasonografía, las tasas de apendicectomías negativas se redujeron de forma significativa, y con ellas disminuyeron la morbilidad y mortalidad asociadas a esta enfermedad. En el presente artículo se revisa la anatomía del apéndice cecal, las manifestaciones clínicas de la apendicitis aguda y los hallazgos de esta entidad en las diferentes modalidades de imágenes diagnósticas, a la luz de la evidencia disponible.

Acute appendicitis is the most common cause of acute abdominal pain which requires surgery. Before the advent of modern diagnostic imaging techniques, the diagnosis of acute appendicitis was exclusively performed by clinical findings; however, the negative appendectomy rates decreased significantly after the introduction of sectional images such as Computed Tomography (CT), Magnetic Resonance Imaging (MRI) and Ultrasonography (U.S.), as well as the morbidity and mortality associated with this disease. In this paper, we review the anatomy of the appendix, the clinical manifestations of acute appendicitis and the findings of this entity in different diagnostic imaging modalities based on available evidence.

Lóbulo piramidal de la glándula tiroides: imágenes en tomografía computarizada / Computed tomography imaging of the pyramidal lobe of the thyroid gland

El lóbulo piramidal de la glándula tiroides es una variante anatómica normal que se presenta con alta frecuencia en la población general. Dicha estructura está compuesta por tejido tiroideo normal, se ubica en la parte superior del istmo tiroideo y se dirige hacia arriba, continuándose con una cinta fibrosa que asciende hasta el agujero ciego en la base de la lengua. En este artículo se revisa de manera breve la anatomía y embriología de la glándula tiroides, para luego hacer una breve exposición acerca de los principales datos anatómicos, epidemiológicos e imágenes de tomografía computarizada del lóbulo piramidal de la glándula tiroides.