RESUMEN
OBJECTIVE: The purpose of this study was to determine the accuracy of IV contrast-enhanced MDCT and MRI for evaluation of the severity and cause of neural foraminal stenosis in patients with cervical radiculopathy. SUBJECTS AND METHODS: Eighteen patients with cervical radiculopathy prospectively underwent contrast-enhanced MDCT and MRI. Contrast-enhanced MDCT scans were acquired at 1-mm thickness and reconstructed in oblique axial (parallel to disk) and sagittal (perpendicular to neural foramen) 2-mm sections without a gap. The MRI sequences used were sagittal T1-weighted, fast spin-echo T2-weighted, 3D fast spin-echo T2-weighted, axial T2-weighted, and 3D gradient-recalled echo. Three neuroradiologists independently and blindly rated the severity and cause of neural foraminal stenosis on a 4-point scale. Using the same scale at surgery, one of three surgeons rated the severity and cause of neural foraminal stenosis, and the results were used as the reference standard. Interobserver and intraobserver agreement (kappa) was calculated. RESULTS: For severity of neural foraminal stenosis, the sensitivities of contrast-enhanced MDCT (50/55, 91%) and MRI (55/57, 96%) were similar, as were their specificities (contrast-enhanced MDCT, 13/24, 54%; MRI, 11/24, 46%). For cause of neural foraminal stenosis, the accuracies of contrast-enhanced MDCT (46/54, 85%) and MRI (45/57, 79%) were similar. Interobserver agreement on severity of neural foraminal stenosis was moderate to almost perfect for contrast-enhanced MDCT (kappa=0.50-1.00) and MRI (kappa=0.43-1.00). For cause of neural foraminal stenosis, interobserver agreement was moderate to substantial for contrast-enhanced MDCT (kappa=0.52-0.76) but only fair for MRI (kappa=0.23-0.39). Intra observer agreement was very high for severity of neural foraminal stenosis (contrast-enhanced MDCT, kappa=0.85; MRI, kappa=0.80) and cause of neural foraminal stenosis (contrast-enhanced MDCT, kappa=0.86; MRI, kappa=1.00). CONCLUSION: Contrast-enhanced MDCT is as accurate as MRI in evaluation of the severity and cause of neural foraminal stenosis and may have better interobserver agreement.
Asunto(s)
Imagen por Resonancia Magnética/métodos , Radiculopatía/diagnóstico , Estenosis Espinal/diagnóstico , Estenosis Espinal/etiología , Tomografía Computarizada por Rayos X/métodos , Adulto , Distribución de Chi-Cuadrado , Medios de Contraste , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Radiculopatía/etiología , Radiculopatía/cirugía , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Estenosis Espinal/cirugía , Resultado del TratamientoRESUMEN
OBJECTIVE: To understand better the relation between media violence exposure, brain functioning, and trait aggression, this study investigated the association between media violence exposure and brain activation as measured by functional magnetic resonance imaging (fMRI) in groups of normal adolescents and adolescents with disruptive behavior disorder (DBD) with aggressive features. METHODS: Seventy-one participants underwent neuropsychologic evaluation and assessment of exposure to violent media. Subjects also were evaluated with fMRI while performing a counting Stroop (CS) task. RESULTS: Frontal lobe activation was reduced in aggressive subjects compared with control subjects. In addition, differences in frontal lobe activation were associated with differences in media violence exposure. Specifically, activation during performance of the CS in control subjects with high media violence exposure resembled that seen in DBD subjects. CONCLUSIONS: Our findings suggest that media violence exposure may be associated with alterations in brain functioning whether or not trait aggression is present.
Asunto(s)
Agresión/fisiología , Lóbulo Frontal/fisiología , Imagen por Resonancia Magnética , Medios de Comunicación de Masas , Violencia , Adolescente , Femenino , Humanos , MasculinoRESUMEN
PURPOSE: To study the correlation of low-frequency blood oxygenation level-dependent (BOLD) fluctuations on magnetic resonance (MR) images obtained of the left- and right-hemisphere primary motor regions in healthy control subjects and patients with multiple sclerosis (MS). MATERIALS AND METHODS: Sixteen healthy volunteers and 20 patients with MS underwent MR imaging with a 1.5-T imager by using a protocol designed to monitor low-frequency BOLD fluctuations. Data for low-frequency BOLD fluctuations were acquired with subjects at rest and during continuous performance of a bilateral finger-tapping task. These data were low-pass filtered (<0.08 Hz), and cross correlations of all acquired pixels to a region of interest in the left precentral gyrus were calculated. Confidence levels were calculated from the cross correlations. The fraction of pixels in the right precentral gyrus above a confidence level of 95% for correlation with the left precentral gyrus was calculated for each subject. RESULTS: A plot of the fraction of the right precentral gyrus with high correlation with the left precentral gyrus for the finger-tapping state versus the resting state showed a clear discrimination between patients with MS and control subjects. Compared with control subjects, patients with MS generally had a smaller fraction of the pixels in the right precentral gyrus above the confidence level. This finding indicates that our method results in greater than 60% sensitivity and 100% specificity for discriminating patients with MS from control subjects. No significant correlation was found between clinical measures of MS disease and correlations of low-frequency BOLD fluctuations between left and right precentral gyri. CONCLUSION: On the basis of the connectivity measure of low-frequency BOLD fluctuations, patients with MS exhibited lower functional connectivity between right- and left-hemisphere primary motor cortices when compared with that in control subjects.