Imaging Flashcards
what imagining methods are used in obs and gynaecologiy
Ultrasound CT MRI X-ray screening fluoroscopy Functional imaging - PET CT
what are the indications for imaging in obs and gynae
Diagnosis of pelvic pain
Assessment of pelvic masses
Investigation of abnormal menstrual bleeding
Assessment of patients with post-menopausal bleeding
Investigation of infertility
Interventional radiology (Fallopian tube recanalisation, uterine artery embolisation etc)
what are the 2 main ultrasound techniques
transabdominal
-scanning using a standard general abdominal US transducer
transvaginal
-scanning using a dedicated end-cavity high frequency transducer
what happens in a transabdominal ultrasound
pelvic organs are scanned through the anterior abdominal wall
perform brief assessment of upper abdomen
the patient must have a full bladder
-acts as an acoustic window
displaces gas filled bowel loops out of the pelvis
what are the benefits of trans abdominal ultrasound
safe
readily available
no ionising radiation and therefor ideal for children and women of reproductive age
what are some disadvantages of trans abdominal ultrasound
difficult to obtain good images in obese patients
operator dependent
difficult to produce the exact same image every time (not good for assessing response to treatment)
why are the external iliac vessels important landmarks in trans abdominal ultrasound
land marks for the ovaries
follow them down to find ovaries
why is transvaginal ultrasound clearer than trans abdominal
higher frequency and gets to closer proximity to the uterus
advantages of transvaginal scanning
excellent depiction of the pelvic organs
disadvantages of transvaginal scanning
more invasive procedure
not suitable for those who haven’t been sexually active
sometimes just demonstrates ‘tip of the iceberg’ and not full extent of large pelvic masses
how do you asses the ovarian volume
take a transvaginal ultrasound scan
one horizontal and one vertical
make 3 points and measure
when is CT used in obs and gynae
2nd line after ultrasound
acute abdominal pain
post -surgical complications
staging of gynaecological malignancy
assessing response to treatment (chemo/radio)
advantages for CT
quick
entire chest, abdomen and pelvis asses in one scan
can take ‘multi slice’ images through the patient allowing you to view the image in 3 different planes
disadvantages of CT
high radiation dose -significant dose given to ovaries
used sparingly in children and patients of reproductive age
does not provide optimal depiction of pelvic organs
when is MRI scanning used in obs and gynae
cancer staging (especially cervical)
further evaluation and characterisation of adnexal and uterine masses
evaluation of patients with sub-fertility
MR of the pituitary if suspected prolactinoma
