SHEAR WAVE ELASTOGRAPHY TECHNIQUES IN DOGS AND CATS: PERSONAL FINDINGS

Shear wave elastography (SWE) is an innovative ultrasound technique which measures the propagation of shear waves produced in response to an ultrasound impulse in the tissue; since shear waves propagate faster in harder tissues, by measuring shear wave speed (SWS) it is possible to obtain information on tissue stiffness. In this thesis we applied SWE techniques to evaluate testicular stiffness in dogs and the spleen of dogs and cats, using Mindray ultrasound equipment. In the first chapter, we summarized the operating principles of elastography, the techniques currently available, the technical factors and the artifacts that can be found in performing the exams. Furthermore, we reported the current state of the art regarding the applications of SWE in dogs and cats. Finally, we described the technical characteristics and the exam procedures of a Mindray machine. In the second chapter, we evaluated the testicular SWS associated to functional integrity and normal semen parameters of breeding dogs. Subsequently, we hypothesized that SWE techniques could help in distinguishing testicular lesions, and we explored this hypothesis by performing pSWE and 2D-SWE on a group of canine testicular abnormalities. In the third chapter we evaluated the spleen SWS in dogs affected by leishmaniosis and in the fourth chapter we compared the performance of two different ultrasound transducers (linear and convex) in the SWE assessment of canine spleen. In the fifth chapter, we evaluated feline spleen stiffness in cats seropositive to Leishmania infantum, feline immunodeficiency virus, and their coinfection, and we compared it to a healthy control group. Moreover, as we grouped our population into awake and anesthetized patients, we compared the spleen SWS between the two groups. In the sixth chapter, we hypothesized that spleen stiffness could be affected by anesthetic drugs, thus we performed repeated 2D-SWE evaluation in groups of healthy dogs before any drug administration, during premedication, and during general anesthesia, to observe the effects of pharmacological agents on splenic stiffness. This work brings new evidence to the literature on SWE in dogs and cats, with preliminary results that encourage the clinical application of this ultrasound technique in the veterinary clinical practice.