Administración intrarterial de un magnetofluido termoterapéutico en un modelo experimental de metástasis hepáticas. Estudio de distribución con resonancia magnética y espectrometría / Magnetic resonance imaging and spectrometric study of the distribution of thermotherapeutic magnetofluid after intra-arterial administration in an experimental model of liver metastases

Objetivo. Valorar la distribución vascular de un magnetofluido por técnicas de imagen y laboratorio, en un modelo de metástasis hepáticas. Material y métodos. El hígado de 33 ratas WAG/RijCrl fue diseminado con células de carcinoma colorrectal CC-531. Tras comprobar desarrollo tumoral, diez ratas recibieron infusiones intrarteriales hepáticas de Lipiodol® con nanopartículas de Fe3O4 en suspensión, y cinco se reservaron como controles. Posteriormente, en RM de 1,5 T se practicaron secuencias axiales STIR (TR: 3.600ms/TE: 29ms/TI: 130ms) y eco de gradiente (EG) (120/4 y 120/14). Tras necropsia, según desarrollo tumoral, las ratas se clasificaron en dos estadios: precoz (< 10 metástasis, de < 3mm), avanzado (> 10 metástasis, de>3mm). De los 15 animales se tomaron muestras de hígado y metástasis, para cuantificar mediante espectrometría (ICP-MS) las concentraciones de hierro. En el análisis estadístico se emplearon pruebas no paramétricas. Se consideraron significativos valores de p < 0,05. Resultados. Cinco animales presentaron afectación precoz y cinco, avanzada. En secuencias EG, las metástasis en estadio precoz mostraron disminución homogénea de señal atribuible a presencia de magnetofluido. La espectrometría demostró diferencias significativas entre la concentración de hierro determinado en metástasis de ratas en estadio precoz y control (p=0,002), y entre animales en estadio precoz y avanzado (p=0,001). La razón entre hierro exógeno metastásico y hepático en ratas en estadio precoz fue 2,6:1. La concentración de hierro exógeno hepático y tumoral mostró diferencias significativas sólo en animales en estadio precoz (p=0,043). Conclusiones. RM y Espectrometría permitieron evaluar la distribución vascular hepática del magnetofluido, y revelaron su desigual afinidad por metástasis en diferentes estadios (AU)

Objective. To use imaging and laboratory techniques to evaluate the vascular distribution of magnetofluid in a rat model of liver metastases. Material and methods. The livers of 33 WAG/Rij Crl rats were seeded with CC-531 colorectal cancer cells. After we checked tumor development, 10 rats received hepatic intra-arterial infusions of Lipiodol® with nanoparticles of Fe3O4 in suspension, and 5 were reserved as controls. Axial STIR (TR: 3,600ms/TE: 29ms/TI: 130ms) and gradient-echo (GE) (120/4 and 120/14) MRI sequences were acquired on a 1.5 T scanner. After necropsy, rats were classified into one of two stages according to tumor development: early (< 10 metastases, each < 3mm) or advanced (> 10 metastases, each > 3mm). Samples of liver and of metastases were taken from the 15 animals for quantification of iron concentrations by inductively coupled plasma mass spectrometry (ICP-MS). The data were analyzed using nonparametric tests; values of p < 0.05 were considered significant. Results. Five animals had early tumor development and five had advanced tumor development. In the GE sequences, early stage metastases showed homogeneous signal reduction attributable to the presence of magnetofluid. Spectrometry found significant differences between the iron concentration in rats with early stage metastases and controls (p=0.002) as well as between rats with early stage metastases and those with late stage metastases (p=0.001). The ratio of exogenous iron in metastases and in liver in early stage rats was 2.6:1. The concentration of exogenous iron in the liver was significantly different from that in tumors only in early stage animals (p=0.043). Conclusions. MRI and spectrometry made it possible to evaluate the vascular distribution of magnetofluid in the liver and revealed the differences in its affinity for metastases in different stages of disease (AU)

[Magnetic resonance imaging and spectrometric study of the distribution of thermotherapeutic magnetofluid after intra-arterial administration in an experimental model of liver metastases]. / Administración intrarterial de un magnetofluido termoterapéutico en un modelo experimental de metástasis hepáticas. Estudio de distribución con resonancia magnética y espectrometría.

OBJECTIVE: To use imaging and laboratory techniques to evaluate the vascular distribution of magnetofluid in a rat model of liver metastases. MATERIAL AND METHODS: The livers of 33 WAG/Rij Crl rats were seeded with CC-531 colorectal cancer cells. After we checked tumor development, 10 rats received hepatic intra-arterial infusions of Lipiodol(®) with nanoparticles of Fe(3)O(4) in suspension, and 5 were reserved as controls. Axial STIR (TR: 3,600 ms/TE: 29 ms/TI: 130 ms) and gradient-echo (GE) (120/4 and 120/14) MRI sequences were acquired on a 1.5 T scanner. After necropsy, rats were classified into one of two stages according to tumor development: early (<10 metastases, each < 3mm) or advanced (>10 metastases, each >3 mm). Samples of liver and of metastases were taken from the 15 animals for quantification of iron concentrations by inductively coupled plasma mass spectrometry (ICP-MS). The data were analyzed using nonparametric tests; values of p < 0.05 were considered significant. RESULTS: Five animals had early tumor development and five had advanced tumor development. In the GE sequences, early stage metastases showed homogeneous signal reduction attributable to the presence of magnetofluid. Spectrometry found significant differences between the iron concentration in rats with early stage metastases and controls (p=0.002) as well as between rats with early stage metastases and those with late stage metastases (p=0.001). The ratio of exogenous iron in metastases and in liver in early stage rats was 2.6:1. The concentration of exogenous iron in the liver was significantly different from that in tumors only in early stage animals (p=0.043). CONCLUSIONS: MRI and spectrometry made it possible to evaluate the vascular distribution of magnetofluid in the liver and revealed the differences in its affinity for metastases in different stages of disease.

Correlación arteriográfica en 30 pacientes con patología vascular renal diagnosticada mediante TC multicorte / Arteriographic correlation in 30 patients with renal vascular disease diagnosed with multislice CT

Objetivo. Determinar la utilidad de la tomografía computarizada multicorte (TCMC) en la valoración de la patología arterial renal, tomando como patrón oro la angiografía con sustracción digital (ASD). Material y métodos. Se evalúan 30 pacientes con hipertensión arterial o insuficiencia renal, a los que se había realizado una TCMC para descartar etiología vascular de su padecimiento, y en los que ante sospecha de la misma, se practicó una ASD de confirmación diagnóstica. Las TCMC se realizaron en un equipo de 10 detectores, con administración intravenosa de 80 ml de contraste yodado (300 mg de yodo/ml) a flujo de 5 ml/s. Se valoraron 71 arterias renales, 56 principales y 15 accesorias. Las estenosis arteriales se clasificaron para su evaluación en: grado 0 (arteria normal), grado I (estenosis < 50%), grado II (>= 50%, pero < 70%), grado III (>= 70%), grado IV (oclusión). Las estenosis de grado II o superior se consideraron hemodinámicamente significativas. Resultados. En 56 arterias renales (78,8%) se realizó una valoración idéntica en TCMC y ASD. En 13 casos (18,3%) la TCMC sobrevaloró el grado de estenosis. Todas las estenosis de grado III fueron detectadas con TCMC. En el diagnóstico de las estenosis hemodinámicamente significativas la TCMC demostró sensibilidad del 96,5%, especificidad del 78,5%, exactitud del 85,9%, valor predictivo positivo del 75,6% y negativo del 97%. Conclusiones. La TCMC es un buen método de imagen no invasivo en la evaluación de los vasos renales, y resulta útil en el cribado de los pacientes con patología nefrológica en los que se busca descartar una etiología vascular potencialmente tratable (AU)

Objective. To determine the usefulness of multislice computed tomography (MSCT) in the evaluation of renal vascular disease against a gold standard of digital subtraction angio -graphy (DSA). Material and methods. We evaluated 30 patients with arterial hypertension and/or kidney failure that underwent MSCT to rule out a vascular cause and DSA to confirm a vascular cause suspected at MSCT. MSCT examinations were performed on a 10-detector scanner with intravenous administration of 80 ml of iodinated contrast (300 mg iodine/ml) at a flow rate of 5 ml/s. A total of 71 renal arteries, 56 main and 15 accessory, were evaluated. Arterial stenoses were classified as: grade 0 (normal artery), grade I (stenosis < 50%), grade II (>= 50% and < 70%), grade III (>= 70%), grade IV (occlusion). Stenosis >= grade II was considered hemodynamically significant. Results. The findings at MSCT and DSA were identical in 56 (78.8%) renal arteries; MSCT overestimated the degree of stenosis in 13 (18.3%) cases. All grade III stenoses were detected at MSCT. In the diagnosis of hemodynamically significant stenosis, MSCT had a sensitivity of 96.5%, specificity 78.5%, accuracy 85.9%, positive predictive value 75.6%, and negative predictive value 97%. Conclusions. MSCT is a good noninvasive imaging technique for the evaluation of renal vessels; it is useful for screening patients with kidney disease to rule out potentially treatable vascular causes (AU)