Week Eleven

VETT 116: Veterinary Diagnostic Imagine 1 Overview of Week 11 There are times in veterinary medicine that regular radiographs are not sufficient as diagnostic tools and additional techniques must be used. Contrast studies, ultrasound, CT and MRI imaging can be used in these cases to accurately diagnose the patient. In order to best assist in the diagnostic process, it is necessary to gain basic understanding of these procedures and the materials they are associated with. This week, we will look at each of these imagine techniques and discuss how they are performed and when they are warranted.

Objectives: VETT 116: Veterinary Diagnostic Imagine 1 Week 11 Objectives Become familiar with the concept of alternative radiographic techniques used inveterinary medicine. List and describe the purpose for radiographic contrast studies in various systems. Become familiar with ultrasound terminology and the basics of ultrasonography. List use and purpose of CT scanning in veterinary medicine. Become familiar the use of MRIs in veterinary medicine and precautions used with this imaging technique.

VETT 116: Veterinary Diagnostic Imaging 1 Important Dates and Deadlines Please see the Student Handbook for a complete schedule with calendar due dates. Week 10 assignment due date Week 12 Final exam, all assignments due

VETT 116: Veterinary Diagnostic Imaging 1 RADIOGRAPHIC CONTRAST MEDIA There are four types of contrast media used in veterinary medicine. Contrast medium = a substance that is either radiolucent or radiopaque and can be administered to an animal to increase radiographic contrast within an organ or system. 1)Radiolucent gases- air, nitrous oxide, carbon dioxide 2)Insoluble inert radiopaque medium- barium sulfate 3)Soluble ionic radiopaque medium- iothalamate, diatrizoate 4)Soluble nonionic radiopaque medium- iohexol, iopamidol These are divided into two basic categories: Positive-contrast agents (high specific gravity)‏ Negative-contrast agents (low specific gravity)‏

VETT 116: Veterinary Diagnostic Imaging 1 Ultrasound Ultrasound = non-invasive method of producing a diagnostic image based on the penetration of a sound wave to and from tissues in the body. Ultrasound Basics Patient Preparation Display Modes Ultrasound Image Artifacts Ultrasound Examinations

VETT 116: Veterinary Diagnostic Imaging 1 Computed Tomography A Computed Tomography (CT) scan is obtained by passing a very thin X-ray beam through the body at multiple sites and measuring attenuation. The computer then gathers the information and forms a cross-sectional image out of the data. CT scan Advantages: Greatly improved contrast Spatial Resolution Cross-sectional presentation Most commonly used for head and spinal cord examinations (neurologic disease)‏

VETT 116: Veterinary Diagnostic Imaging 1 Magnetic Resonance Imaging MRI imaging is similar to CT imaging as it also uses thin slices of cross- sectional anatomy. However, it does not use ionizing radiation to create the image and does use magnets. MRI is superior to CT in: Image resolution Anatomic definition Sensitivity to tissue Two types of MRI units/magnets: Low field strength High field strength (superconductive)‏

VETT 116: Veterinary Diagnostic Imaging 1 Additional Resources CT Applications in Veterinary Medicine What is Ultrasound? How MRI Works Advanced Veterinary Technologies