Asunto(s)
Medios de Contraste , Aceite Yodado , Imagen por Resonancia Magnética , Compuestos Organometálicos , Ácido Pentético/análogos & derivados , Animales , Medios de Contraste/farmacocinética , Medios de Contraste/toxicidad , Fibrosarcoma/diagnóstico , Gadolinio DTPA , Aceite Yodado/farmacocinética , Aceite Yodado/toxicidad , Masculino , Ratones , Compuestos Organometálicos/farmacocinética , Compuestos Organometálicos/toxicidad , Ácido Pentético/farmacocinética , Ácido Pentético/toxicidad , ConejosRESUMEN
We evaluated the clinical efficacy of an embolizing emulsion produced by mixing lipiodol and Gd-DTPA, in transcatheter arterial chemoembolization (TAE). Subjects were 10 patients with hepatocellular carcinoma (HCC). The emulsion used was produced by mixing 3 ml of lipiodol and anticancer agents (mitomycin-C 10 mg and adriamycin 20 mg) dissolved in Gd-DTPA. This emulsion was infused into the proper hepatic artery. Subsequent embolization by Gelfoam was performed in eight patients. MRI and CT examinations were performed soon after TAE (1 or 2 days after) and two weeks afterwards. The position of lipiodol accumulation dipicted on CT at two weeks after TAE did not differ from the site of change in signal intensity induced by Gd-DTPA on MR images soon after TAE in any case. In almost all cases, the washout of Gd-DTPA occurred earlier than that of lipiodol. It might be suggested that Gd-DTPA, which is water-soluble, shows in vivo dynamics similar to anticancer agents rather than to lipiodol, which is oil-soluble. Since the normal tissues showed no definite signal changes, we could easily detect the site of tumors by using the emulsion containing Gd-DTPA even on MR studies immediately after TAE. In addition, the deposits of Gd-DTPA depicted on MR images created fewer artifacts than the lipiodol deposits on CT.
Asunto(s)
Quimioembolización Terapéutica/métodos , Medios de Contraste , Aceite Yodado , Neoplasias Hepáticas/terapia , Compuestos Organometálicos , Ácido Pentético/análogos & derivados , Adulto , Anciano , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Emulsiones , Femenino , Gadolinio DTPA , Humanos , Neoplasias Hepáticas/diagnóstico , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos XRESUMEN
Scatter to primary radiation ratios at detector positions were calculated for uniform cylindrical water phantoms in both third and fourth generation x-ray CT scanners using the Monte Carlo simulation method. A rapid method for determining the scattering angle is given. In the process of image reconstruction, the effect of scatter was isolated by applying our new calculation technique. The decrease in CT number due to scatter was found to be less than 10. In the third generation CT scanner the rate of scatter is larger at the centre than at the edge because of the effect of the collimator at the detectors. As a result the cupping artefact occurs in the CT image. The collimator cannot be used in the fourth generation CT scanner and, therefore, the rate of scatter is almost uniform, leading to the appearance of rounded-off edges.