Study of magnetic resonance of 1,0 T as a method of imaging in vivo of the experimental hydrocephalus: on the application of the method to evaluate the size of the ventricles in rats submitted to ventricular shunts

THESES

Study of magnetic resonance of 1,0 T as a method of imaging in vivo of the experimental hydrocephalus: on the application of the method to evaluate the size of the ventricles in rats submitted to ventricular shunts (Abstract)^*. Thesis. Ribeirão Preto, 2003

Samuel Caputo de Castro

^{Correspondence}

Magnetic resonance imaging (MRI) equipments of high field, dedicated specifically to experimental uses, have been used to study the hydrocephalus in vivo of small rats carriers of congenital hydrocephalus. In this experiment the MRI of 1,0 T (the same used to investigate neurological diseases in humans is evaluated as an imaging method to study in vivo the size of the ventricles of hydrocephalic rats of the race Wistar.

To accomplish this study, 33 rats had become hydrocephalic through the intracisternal injection of caulim. The parameters, Ventricular Ratio, Cortical Thickness and Ventricular Area, were measured at the digital picture of the MRI slice and at the anatomical slice of the brain. At eye vision, the quality of the images were sufficient to distinguish the ventricular cavities from the brain.

The ventricular ratio was the most confidant parameter to compare, resulting in a correlation ratio of 0.95. The MRI overestimated the ventricular area in an average of 36.23%. The imaging method was applied to evaluate the size of ventricles of hydrocephalic rats submitted to a surgical ventricular shunt.

Beforehand, in order to determine the best surgical procedure, 14 hydrocephalic rats were submitted to ventricle-subcutaneous shunts, 9 to ventricle-peritoneal shunts and 6 to ventricle-pleural shunts. The ventricular-subcutaneous shunt to the neck demonstrated to be the best surgical procedure to treat the hydrocephalus in this model, because it was technically easier, faster to perform, presented less complications and has been more secure than the others to check up the patency of the system.

In another group of 26 hydrocephalic rats, the shunts to the subcutaneous tissue of the neck were more efficient to reduce the size of the ventricles when performed in animals injected, operated upon and were sacrificed much earlier than the ones injected, operated upon and sacrificed late.

Key words: experimental hydrocephalus, magnetic resonance, experimental surgery.

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*

Avaliação da ressonância magnética de 1,0 T como método de imagem in vivo da hidrocefalia experimental: aplicação do método na avaliação do tamanho dos ventrículos em ratos submetidos à derivação liquórica (Resumo). Tese de Doutorado, Universidade de São Paulo (Área: Cirurgia). Orientador: Hélio Rubens Machado.

Publication Dates

• Publication in this collection
  13 Apr 2005
• Date of issue
  Mar 2005