Imaging in gynaecology Flashcards
What imaging methods are utilised in gynae radiology?
In order of most useful: USS CT MRI X-ray (HSG) PET
What are the indications for gynae radiology?
Dx of pelvic pain
Assessment of pelvic masses
Ix of AUB
Assessment of post-menopausal bleeding (endometrial thickness)
Ix of fertility (HSG, MR pituitary)
IR; fallopian tube recanalisation, uterine artery embolisation
What are the 2 USS techniques utilised in gynae?
Transabdominal
Transvaginal - detailed scan of uterus and ovaries
What is a transabdominal ultrasound?
Pelvic organs are scanned through the anterior abdominal wall
What should be included in a brief assessment in the transabdominal USS?
Hydronephrosis
Early ascites
Ensure that the pelvic abnormality is not secondary to upper abdominal pathology
Why must the patient have a full bladder for a transabdominal USS?
A urine-distended bladder acts as an acoustic window
A distended bladder displaces gas filled bowel loops out of the pelvis (bowel gas scatters USS beam and degrades image quality)
Advantages of transabdominal USS?
Safe
Readily available
No ionising radiation and therefore ideal for children and women of reproductive age
Disadvantages of transabdominal USS?
Difficult to obtain good images in obese patients and in patients where there is gaseous distention of bowel
Operator dependent
Difficult to produce exactly the same images every time patient attends and this means uss is not often used for assessing the response to cancer treatment
To what vessels are the ovaries in close proximity to?
External iliac vessels
What are the benefits of transvaginal scanning?
Higher frequency ultrasound, has a shorter wavelength and better spatial resolution but higher frequencies are more likely to be scattered in the body and the ultrasound transducer has to be close to the target organ
Should the bladder be empty of full for transvaginal scanning?
Empty bladder
Advantages of TVUSS?
Excellent depiction of pelvic organs
Disadvantages of TVUSS?
More invasive
Not suitable for individuals who have not been sexuallly active
Can sometimes demonstrate the tip of the iceberg and may not depict the full extend of large pelvic masses
What is an anteverted uterus?
Pointing towards bladder
Describe the different ovary volumes?
PCOS; increased
Failure; reduced
Where will fluid accumulate in a ruptured ovarian cyst when lying down?
Hepatorenal recess
When is a CT used in gynae radiology?
2nd line to acute abdo pain
Post-surgical cx; small bowel obstruction secondary to adhesions, post-op collections/ abscesses
Staging of gynae malignancy, esp ovarian and endometrial ca
Assessing response to tx in patients after chemo +/- radiology
Advantages of CT scanning?
Quick
Entire chest, abdo and pelvis can be assessed on one scan
Modern multiple detector row scanners produce very thin slices and images can be manipulated to produce coronal and sagittal reformats as well as the axial source images
Disadvantages of CT scanning?
High radiation dose with a significant dose delivered to ovaries
Used sparingly in children and patients of reproductive age
Does not provide optimal depiction of different pelvic organs (MR better at tissue resolution)
What does fat within a cyst indicate?
Dermoid cyst
Difference between T1 and T2 weighted imaging?
T1 = fat, protein and blood = bright
T2 =fat and water bright. More fluid sensitive
Advantages of MRI
Excellent depiction of pelvic organs
No ionising radiation; suitable for children and women of reproductive age
Can give idea about composition of soft tissue masses; do they contain fluid? Do thy contain fat? do they contain blood?
Can MRI be given in all stages of pregnancy?
Try to avoid 1st trim
Disadvantages of MRI?
Time consuming
Poor depiction of lungs; CT scan is query pulmonary mets
Not tolerated in claustrophobia
CI: pacemakers, heart valves, nerve stimulators, cochlear implants
