RESUMO O ultra-som bidimensional e o ultra-som Doppler foram utilizados para avaliar a biometria e a hemodinâmica da aorta abdominal e artérias ilíacas externas

ABSTRACT.-Hage M.C.F.N.S., Iwasaki M., Rabbani S.R., Kamikawa L., Cervantes H.J.R., Bombonato P.P., Sterman F. Magnetic resonance imaging (MRI) is the most sensitive method of diagnostic imaging to evaluate soft tissues, specially the brain, however it is expensive. The method is based on the nuclear magnetic resonance phenomenon that occurs when atomic nucleus with magnetic proprieties in the body are submitted to a strong magnetic field, and excited with radio frequency generating a radio frequency signal captured by a receptive antenna. The signal is processed by Fourier Transform for the image formation. This study had the objective to obtain 10 complete exams of heads in cadavers of normal dogs to MRI and to make an Atlas of head structures. The images were obtained with a magnetic resonance unit Gyroscan S15/HP Philips using a magnetic field of 1,5Tesla. The cadavers were positioned with the head into a human head coil and submitted to sagittal slices used to plan transverse and dorsal slices in T1, T2 and DP spin-echo sequences. In T1 we adjusted TR=400ms and TE=30ms, in T2 TR=2000ms and TE=80ms and in DP TR=2000ms and TE=30ms. The slice thickness was 4mm, the number of averages 2, the matrix 256x256, the factor 1,0 and the field of view 14cm. The duration of the complete exam of the head was 74,5minutes. The images obtained with the described sequences and with the human head coil was of good quality. In T1 fat was hyperintense and fluid was hypointense. In T2 fat was less hyperintense and fluid was hyperintense. The cortical bone and the air were hypointense in all sequences used because of the low proton density. The DP sequence showed the best contrast between white and gray matter when compared with T2 and T1 sequences. Distinction of cerebral sulcus and gyrus was possible because T2 showed the cerebrospinal fluid. The identification of bone structures that compound the region, muscles, main venous and arterial vessels and structures of the central nervous system, besides elements of the digestory and respiratory systems and structures of the eyes among others was possible through contrast obtained with MRI. In this study the MRI acquired in T1, DP and T2 were complementary for the anatomic study of the head and been able to demonstrate the structures of the canine head with rich anatomic details. The time used to 1 Recebido em 29 de novembro de 2009. Aceito para publicação em 24 de fevereiro de 2010.

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Pesq. Vet. Bras. 32(9):941-946, setembro 2012 941 RESUMO.-Foram realizados o estudo morfométrico e o estudo hemodinâmico da veia porta em vinte cães clinicamente normais, de idade igual e inferior a 120 dias e em quatorze cães portadores de shunt portossistêmico, de idades entre 90 e 360 dias. Nos cães do grupo controle, as margens hepáticas apresentaram-se entre 1,50cm e 3,00cm caudalmente à margem costal. Os diâmetros médios da veia porta (VP), veia cava caudal (VCC) e aorta abdominal (AO) obtidas foram respectivamente, 0,38cm, 0,37cm e 0,41cm. As proporções entre os diâmetros médios VP/ The morphometry and haemodynamic aspects of portal vein were studied in 20 normal dogs with less than 120 days of age and in 14 dogs presenting portosystemic shunting with ages between 90 and 360 days. In the control group the hepatic margins were seen 1.50cm to 3.00cm caudal to the costal margin. Collected data indicated that the mean diameter of portal vein (VP), caudal vena cava (VCC) and abdominal aorta (AO) measured respectively, 0.38cm, 0.37cm and 0.41cm. The VP/VCC and VP/AO mean ratios were respectively, 1.10 and 0.94. The average of VP, VCC and AO areas were respectively, 0.12cm 2 , 0.11cm 2 and 0.14cm 2 . The haemodynamic of portal vein was studied by ultrasound Doppler and the mean velocity of portal blood ϐlow (VMFSP) measured was 17.76cm/s. It was veriϐied that portal blood ϐlow (FSP) average was 83.11ml/min/kg and the congestion index (IC) average was 0.006. In the group of animals presenting portosystemic shunting, the hepatic margins were seen 1.00cm to 2.00cm cranial to the costal margin. The morphometry of VP, VCC and AO presented a mean diameter of 0.40cm, 0.74cm and 0.56cm, respectively. The VP/VCC and VP/AO mean ratios were respectively, 0.54 and 0.69. The average of VP, VCC and AO areas were respectively, 0.