Ultrassonografia quantitativa da degeneração testicular induzida em ovinos

Abstract

In this thesis, made up of two experiments, in different processes of testicular degeneration in rams it was evaluated the efficiency of ultrasonography with the grayscale histogram technique. The First Experiment was carried out with the aim of monitoring the progression of induced ischemic degeneration validate analyzes of echogenicity and ecotexture patterns, also evaluating the scrotal perimeter and testicular volume. The males (n = 6), aged 11 and 18 months, underwent testicular biometry analysis to obtain the scrotal and testicular volume, and acquisition of ultrasound images were performed to determine echogenicity and echotexture values in the GIMP software 2.8® for determination of pre-ischemia patterns. The measurements of these parameters were performed before mechanical ischemia induced with burdizzo (D0) and on days 1 (D1), 4 (D4), 8 (D8), 16 (D16), 24 (D24), 35 (D35) and 50 (D50). The value of echogenicity in the healthy testicle was 105.01 ± 8.23 and that of the ecotexture by echo variation was 13.24 ± 0.88. The behavior of the echogenicity, represented by the numerical value of the pixel, showed that the mechanical impedance of the testicular irrigation exerted influence (P <0.05) already from the first day (D1) after this procedure, which continued in decline that was observed in D4 with a value of 50.11 ± 7.21 (P <0.05). It was remained the pixel value constant until the 35th day and was only recovered at the end of the experiment (D50), when the fibrosis process replaced. The tissues of the testicular parenchyma and provided a significant increase (P <0.05) in echogenicity to a value of 62.19 ± 7.15, similar to the value verified in D1 (P> 0.05). The behavior of the numerical value of the ecotexture, which was initially 13.24 ± 0.88, showed that only from the D4, there was an increase (P <0.05) in the homogeneity of the testicular parenchyma ecotexture relative to the D0 decreasing to values Of 11.01 ± 1.61. A fact also observed on the other days of evaluation, except for the one performed in the D50 that increased the heterogeinity to 14.42 ± 1.77. It is ended that for an acute lesion, echocardiographic values obtained by amplitude of echo variation is not sufficient to support a precise diagnostic evaluation, being necessary to correlate with the alteration of echogenicity values and that, macroscopically; testicular degeneration is characterized by the reduction of the scrotal perimeter and testicular volume. The Second Experiment aimed to evaluate the role of quantitative gray scale analysis in the ultrasonographic images of sheep testicles with scrotal insulation, accompanying their degeneration and recovery phases. We used six adult non - defined animals aged 18 to 20 months. We divided the experiment into three periods. It performed in the pre-insulation period, semen analysis, testicular biometry and ultrasonographic imaging for subsequent quantitative computational analysis of ecotexture and echogenicity using the gray histogram to establish a normality pattern. It placed in the scrotal insulation phase, tissue pouches, involving the scrotum, with a double wall and inner layer of hydrophobic cotton with about five mm. (D4I). We performed measurements of testicular biometric, spermogram, and ultrasonographic imaging. The post-insulation phase started with the withdrawal of the bags, it considered this day as day 0 and testicular measurements, semen collections, and testicular measurements and ultrasound monitoring were performed every seven days until the seminal parameters were recovered. In testicular biometry, the length and scrotal volume measurements decreased on the first day of the post-insulation period (P <0.05). Among the sperm parameters, a decrease (P <0.05) was observed, with 4 days of thermal stress of motility, vigor and turbulence, 35 ± 20.74%, 1.83 ± 0.75 (0-5), 2, 3 ± 0.47 (0-5) respectively, associated with a decrease in echogenicity, which was initially 100 ± 4.9 and 99.69 ± 5.3 pixel intensity. After four days of thermal stress, echogenicity had a Drop to values of 73.1 ± 14.2 (P <0.05) increase for values close to those of the pre-insulation period that occurred at 63 days post-insulation period. The ecotexture did not change in the values initially (P> 0.05) without variation in the ecotexture. Ecogenicity showed a precocity with respect to the other parameters in return to the standards defined in the preinsulation period. It was concluded that the induction of thermal stress was characterized by a reduction of testicular biometry, a decline in seminal quality and a decrease in pixel intensity in the ultrasound image, the latter being a sensitive parameter both in the acute phase together with motility, vigor and turbulence, and Testicular recovery, showing itself earlier than other parameters.