IMAGING - Reproductive Tract Flashcards
Which ultrasound probe should you use for imaging the reproductive tract?
Microconvex probe
What frequency settings should you use when doing an ultrasound of the reproductive tract?
Use the highest frequency settings available when imaging the reproductive tract to achieve increased resolution. Be aware in larger patients you may have to reduce the frequency to increase the penetration
Which structures of the male reproductive tract are typically evaluated with diagnostic imaging?
Prostate
Testes
Penis
Which physiological factors can result in altered appearance of the prostate on imaging?
Age
Breed
Neutering status
Bodyweight
Where is the prostate located?
The prostate is a retroperitoneal structure located caudal to the neck of the bladder and surrounded by periprostatic fat (thus more challenging to visualise in obese patients). The proximal urethra divides the prostate into a bilobed structure
How can the position of the prostate change when the bladder is full?
When the bladder is full, this can move the prostate cranially further into the abdomen
This can potentially make the prostate easier to visualise
What can be done to help visualise the prostate?
Wait until the bladder is enlarged
Urinary catheterisation and artificially enlarge the bladder with saline
What is the normal size of the prostate?
The prostate should not exceed 70% of the diameter of the pelvic inlet
This can be challenging to evaluate on ultrasound, however radiography can give you a better overview
When is it particularly challenging to evaluate the prostate on diagnostic imaging?
It is particularly challenging to evaluate the prostate on diagnostic imaging when it is in an intrapelvic location, which is more common in neutered males where the prostate is smaller in size
What is radiography useful to assess when visualising the prostate?
Size
Mineralisation of the parenchyma
Which imaging modality is ideal for visualising the prostate?
Ultrasound
Where should you position and move the ultrasound probe to scan the prostate?
Have the patient in right lateral recumbency and have an assistant lift the left hindlimb. Place the ultrasound probe at an oblique angle and identify the bladder, then direct the probe caudally along the bladder neck until you identify the prostate
How does the prostate appear in entire males on ultrasound?
Hyperechoic
Homogenous
How does the prostate appear in neutered males?
Small
May be hypoechoic relative to the periprostatic fat
Often challenging to identify
What is a common pathological change seen in the prostate?
Prostamegaly
How do normal testes appear on radiography?
On radiography, the testes are located caudal to the pelvis and appear as bilobed, soft tissue opacity
How do normal testes appear on ultrasound?
Rounded, bean shaped structure with a hypoechoic mediastinum and central hyperechoic band
Which structures of the female reproductive tract are typically evaluated with diagnostic imaging?
Uterus
When can the uterus be identified on radiography?
The uterus is not typically identified on radiography unless the diameter exceeds twice the width of the small intestine
Which physiologica features can cause alterations in the size of the uterus?
Individual patient
Age
Stage in the oestrous cycle
Neutered status
Time of day
Which imaging modality is preferable for evaluating the uterus?
Ultrasound
Where should you position and move the ultrasound probe to scan the uterus?
Have the patient in right lateral recumbency and have an assistant lift the left hindlimb. Put the probe onto the caudal abdomen and identify the bladder, scan dorsally until you find the uterus (dorsal to the bladder and ventral to the colon)
How should the uterus appear on ultrasound during anoestrus?
During anoestrus, the uterine wall will be thin with no fluid present and it will be very challneging to visualise the uterus
How should the uterus appear on ultrasound during proestrus?
During proestrus, a small amount of hypoechoic to anechoic fluid can be present with a varying degree of wall thickness
How should the uterus appear on ultrasound during metoestrus?
During metoestrus, the endometrium will be thickened due to progesterone driven glandular hyperplasia and the uterus will be easier to visualise
How can you differentiate the uterus from intestine on ultrasound?
Intestines have defined layering in their wall however the uterus does not
When can pregnancy be detected on ultrasound in the bitch?
Pregnancy can be detected as early as 18 - 20 days
When can pregnancy be detected on ultrasound in the queen?
Pregnancy can be detected as early as 10 - 11 days
What can be used to age the foetuses using ultrasound?
Chorionic vesicle diameter
Rumb length
Head diameter
Body diameter measurements
What is a reliable indicator of foetal viability on ultrasound?
Foetal heart rate
What should the normal foetal heart rate be?
The normal foetal heart rate should be 2x the rate of the maternal heart rate
(T/F) Ovaries can be easily visualised on radiography and ultrasound
FALSE. Ovaries are very challenging to visualise on ultrasound and cannot be seen on radiography
Where are the ovaires located?
The ovaries are located caudal to the ipsilateral kidney
What is the normal appearance of the ovaries on ultrasound?
Hypoechoic structures surrounded hyperechoic fat. There can be follicles or corpus lutea present
Which physiological factors can cause a varying size and appearance of the ovaries?
Stage of the oestrous cycle can cause variation in the appearance of the ovaries
How should the ovaries appear during anoestrus?
Smooth, rounded and uniformly hypoechoic
How should the ovaries appear during proestrus?
Multiple follicles can be visualised. These will be thin-walled and filled with anechoic fluid
How should the ovaries appear during oestrus?
The follicles regress and corpus lutea will develop. However, immature corpus lutea and follicles have a very similar appearance, whereas mature corpus lutea appear oval and hypoechoic
