Imaging Assessment in Gynaecology Flashcards
What imaging modalities are used in O+G?
Ultrasound CT MRI X-ray screening fluoroscopy – e.g. hysterosalpingograms (HSG) Functional imaging – PET-CT
What are the indications for using radiology in O+G?
Diagnosis of pelvic pain Assessment of masses Ix of abnormal menstrual bleeding Assessment of patients with PMB Ix of infertility (also MR pituitary) Interventional radiology- fallopian tube recanalization, uterine artery embolization etc
Does US have any ionising radiation?
No
What two main US techniques are used?
Transabdominal
Transvaginal- using endocavity high-frequency transducer
Both techniques are often used at same attendance
Why must the patient have a full bladder during transabdominal US?
The urine-distended bladder acts as an “acoustic window”
A distended bladder displaces gas-filled bowel loops out of the pelvis (bowel gas scatters the ultrasound beam and degrades image quality)
In what state must the bladder be during a transvaginal US?
Empty
When is CT scanning used in O+G?
2nd line Ix after US in patients presenting with acute abdominal pain
Assess post surgical complications
Staging of malignancy
Assess treatment response after chemo/radiotherapy
What does MRI use in scanning?
Radiofrequency energy rather than ionising radiation
How is MRI used in O+G?
Cancer staging- especially cervical
Further evaluation and characterisation of adnexal and uterine masses
Sub-fertility evaluation
MRI pituitary glad with suspected prolactinoma
What difficult to diagnose disease can be diagnosed through MRI rather than through diagnostic laparoscopy?
Endometriosis
Why can endometriosis sometimes be diagnosed through MRI?
Deposits contain altered blood and haemoglobin degradation products
These cause characteristic MR signal changes, and, in the appropriate clinical context, endometriosis can be diagnosed on MRI scans
Altered blood returns high-signal on T1 sequences (i.e. it looks white on the scan) whereas it returns lower signal on T2 sequences (looks grey)
Fat can also look white on T1 weighted scans but it appears dark on special fat-suppression sequences
What cyst is hard to diagnose on US but easier on CT or MRI?
Dermoid
What is hysterosalpingography (HSG) used for?
Assessment of tubal patency in patients with infertility
Outline of uterine cavity
How is HSG carried out?
Cervix is cannulated and radiopaque contrast instilled to fill uterine cavity (prior to instillation, control film is obtained)
Real-time imaging
How is radiology used in ovarian cancer?
Initial diagnosis made by US
CT scanning for staging
