RESUMEN
PURPOSE: To determine the accuracy and reliability of magnetic resonance (MR) angiography for identification of stenosis and patent distal vessels in patients with peripheral vascular disease. MATERIALS AND METHODS: Two-dimensional time-of-flight MR angiography and conventional arteriography were performed in 22 patients. Four blinded radiologists independently graded multiple anatomic segments. RESULTS: MR angiography allowed detection of more patent vessel segments than did conventional arteriography. For detection of significant stenosis (> 75%), MR angiography had 43%-67% sensitivity and 74%-89% specificity. Discrepancies in detection of significant stenosis occurred in 39 segments for the most accurate reviewer; 27 of these discrepancies were avoidable. CONCLUSION: For detection of significant stenosis, MR angiography has low to moderate sensitivity and specificity; however, observer variability appears to be a major contributing factor to the discrepancies. Greater reviewer experience or techniques for improving reliability may improve the accuracy of MR angiography in peripheral vascular disease.
Asunto(s)
Arteriopatías Oclusivas/diagnóstico , Pierna/irrigación sanguínea , Imagen por Resonancia Magnética , Adulto , Anciano , Anciano de 80 o más Años , Angiografía , Arteriopatías Oclusivas/diagnóstico por imagen , Vasos Sanguíneos/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Sensibilidad y EspecificidadRESUMEN
The ultrastructure of the hepatic sinusoids of the goat was examined. Contrary to current belief concerning this and other ruminant species, we found the sinusoids to be lined by a smooth, continuous layer of endothelium, broken only by the presence of numerous, unoccluded fenestrae which provide a direct path of communication between the sinusoidal lumen and the space of Disse. Therefore, we suggest that a sieving function similar to that which has been shown to occur in rats may be attributed to the sinusoidal endothelium of the goat.