Large Animal Reproductive Imaging

Safe, cost-effective, more readily available, real-time, adds dimension to physiologic data

Advantages of large animal repro imaging

Requires training, not capable of evaluating tissue types with high acoustical impedance (e.g. bone, air)

Disadvantages of large animal repro imaging

Amplitude, wave length, frequency

Principles of ultrasonography

Amplitude

Sound wave strength; energy transported

Wave length

Area of compression

Frequency

Number of wave cycles per unit of time

One

One hertz (1 Hz) = _ wave cycle(s)

1

One megahertz (1 MHz) = _ million cycle(s)

Transducer 7.5 MHz

Used for transrectal ultrasounds

Higher

Lower frequency —> ___ [lower or higher] penetration

Higher

Higher frequency —> ___ [lower or higher] resolution

Transducers 2.5-3.5 MHz

Used for transabdominal ultrasound or transvaginal procedures

Doppler effect

Frequency alterations that occur when ultrasound interacts with moving objects to quantify the direction and velocity of blood

Color, power

Types of Doppler

Power doppler

Useful for detection of small diameter vessels; no info on velocity or direction of blood flow

Vagina, cervix, uterus, ovaries

Structures evaluated during a routine repro examination to determine the stage of the cycle

Orange slice

What does a high degree of uterine edema look like on ultrasound?

High degree of uterine edema, dominant follicle, soft cervix

Signs of estrus