Significance of Intramedullary High Signal Intensity on Magnetic Resonance Imaging in Patients with Cervical Ossification of the Posterior Longitudinal Ligament

BACKGROUND: The purpose of this study was to analyze the relation between intramedullary high signal intensity (IMHS) on magnetic resonance imaging (MRI), radiographic parameters, and clinical symptoms in cervical ossification of the posterior longitudinal ligament (OPLL) patients. METHODS: Two hundred forty-one patients, who underwent simple radiography, computed tomography (CT), and MRI were included in the present study. As radiographic parameters, the OPLL occupying ratio and occupying area were measured on CT images. Dynamic factors were assessed by measuring cervical range of motion (ROM) on simple radiographs. Visual analog scale (VAS) for neck and arm pain, and Japanese Orthopaedic Association (JOA) scores were evaluated for clinical analysis. The differences in radiographic and clinical findings were assessed between patients with IMHS on T2-weighted MRI findings (group A) and patients without IMHS (group B). RESULTS: Eighty-one patients were assigned to group A and 160 patients to group B. The occupying ratios were found to be higher in group A than in group B on both sagittal and axial views (p < 0.01). Group A also showed a higher area occupying ratio (p < 0.01). The length and area of underlying spinal canal on the sagittal and cross-sectional planes were lower in group A than in group B (p < 0.01). No significant difference in ROM was observed (p = 0.63). On the clinical findings, group A had a lower JOA score (p < 0.001), and no intergroup differences in VAS scores were observed. CONCLUSIONS: In cervical OPLL cases, IMHS on MRI was associated with manifestation of myelopathic symptom. Occupying ratio was associated with high signal intensity on MRI, whereas no association was found with ROM. Occurrence of high signal intensity increased inversely with the length and area of underlying spinal canal.

Classificação por ressonância magnética da degeneração do disco intervertebral / Classification of intervertebral disc degeneration by magnetic resonance

Os autores propõem uma análise da degeneração dos discos intervertebrais de cadáveres através de exame de ressonância magnética. Foram coletadas nove peças de coluna lombar de cadáveres frescos as quais foram submetidas a exame de ressonância magnética. As imagens foram analisadas e classificadas de acordo com o grau de degeneração sendo proposta uma subdivisão no tipo IV em IV-a e IV -b. A análise de 44 discos intervertebrais encontrou uma distribuição de 4,5 por cento do tipo I, 40,9 por cento do tipo II, 32 por cento do tipo III e 18 por cento do tipo IV-a. Houve 4,5 por cento em que não houve concenso entre os examinadores. Os autores concluíram que a perda do sinal do disco nas imagens ponderadas em T2 pode ser correlacionada com a progressiva degeneração do disco. A correlação das alterações encontradas nas imagens produzidas pela ressonância magnética devem ser padronizadas e classificadas para sua melhor compreensão.

The authors suggest an analysis of the degeneration of intervertebral disks on human cadavers using magnetic resonance imaging. Nine lumbar spines were collected from fresh human cadavers and resonance images were captured. The images were analyzed and classified according to the degeneration grades, with the authors proposing a subdivision of type IV into IV-a and IV-b. Forty-four intervertebral disks were analyzed and authors found the following distribution: 4,5 percent type I; 40,9 percent type II; 32 percent type III and 18 percent type IV-a. However, the investigators disagreed with the conclusions in 4,5 percent of the disks. The authors found that the progressive signal lost in the T2-weighted images may be correlated to disk degeneration. Changes found in the magnetic resonance images must be standardized and classified for providing a better understanding.

Resonancia magnetica funcional: una nueva herramienta para explorar la actividad cerebral y obtener un mapa de su corteza / Functional magnetic resonance imaging: a new tool to explore the cerebral activity and to obtain a map of its cortex

La Resonancia Magnetica Funcional permite la detección e identificación de áreas del cerebro durante su actividad, este hecho la diferencia de las imágenes tradicionales de resonancia magnética que solo aportan una visión anatómica del cerebro. El objetivo de este artículo es compatir la experiencia de una reciente estadía, en el Hospital de Niños de Miami, centro de investigación en este tema.

Tissue damage caused by Bothrops sp envenoming evaluated by magnetic resonance imaging (MRI)

The objective of this clinical study was to evaluate local tissue damage caused by Bothrops sp envenoming in relation to lesion type and damaged tissues using magnetic resonance imaging (MRI). Fifteen patients bitten by Bothrops snakes were treated at the Emergency Unit of the Tropical Diseases Unit at the University Hospital, Botucatu School of Medicine, UNESP, Säo Paulo State, Brazil. After receiving specific serotherapy, the patients were submitted to MR of the bite site. T1 spin-echo MRI were obtained revealing the following lesions: edema (n=9), edema associated with hemorrhage (n=5), and hemorrhage (n=1). Perimuscular areas (n=6) and subcutaneous tissues (n=5) were the most affected, followed by muscular tissues (n=4). It is important to mention that MRI did not show myonecrosis of the bite site, a widely reported finding in anatomical and histopathological experimental studies.

Disfunción de la articulación témporomandibular: evaluación con resonancia magnética / Temporomandibular joint disfunction: MR Imaging

El propósito del trabajo es demostrar la utilidad de la resonancia magnética (RM) en el diagnóstico de la patología interna de la articulación témporomandibular (ATM) en pacientes con clínica de disfunción. Se estudiaron 80 ATM pertenecientes a 40 pacientes con un equipo de 1 Tesla. Los resultados muestran que el 83,3 por ciento de las ATM con síntomas no específicos de disfunción articular, y el 9 por ciento en el grupo control (ATM de pacientes asintomáticos). De los hallazgos patológicos, el más importante fue la luxación del disco intraarticular. La RM es el método más adecuado para el estudio de la disfunción articular de la ATM, dada su inocuidad y la excelente correlación clínica obtenida

Refuerzo de la duramadre adyacente a los meningiomas luego de la administración de Gadolinio en RM: sensibilidad y especificidad / Reincenforcement of the dura adjacent to meningiomas after administration of Gd in MRI: sensitivity and specificity

Los autores evalúan el valor de la administración de Gd DTPA en el diagnóstico de meningiomas madiante RM en un estudio restrospectivo sobre 184 pacientes con masas tumorales de diferentes etiologías, de los cuales 14 eran meningiomas confirmados por cirugía. La edad promedio de los pacientes fue de 62.7 años. Los resultados confirman que en estos casos la toma de Gd DTPA en RM de la duramadre en base a la implantación de la masa tumoral, constituye un signo de valor diagnóstico importante, que en esta serie tuvo una sensibilidad y especificidad del 100