Imaging in Gynaecology

Question 1

What imaging methods can be used in gynaecology?

Answer 1

• Ultrasound
• CT
• MRI
• X-ray fluoroscopy – e.g. hysterosalpingograms (HSG)
• Functional imaging – PET-CT

Question 2

What indications would make you consider gynaecological imaging?

Answer 2

• pelvic pain
• pelvis mass
• abnormal menstrual bleeding
• post menopausal bleeding
• infertility

Question 3

In what gynaecological cases may you consider interventional radiology?

Answer 3

• Fallopian tube recanalisation (clear blockages)

- uterine artery embolisation

Question 4

When may a pituitary MRI be considered alongside gynaecological imaging?

Answer 4

If patients bloods show high prolactin

may be coming from a pituitary adenoma

Question 5

Where can a gynaecological US scan be performed?

Answer 5

• Radiology departments
• Gynaecology clinics
• Some GP practices

Question 6

What disadvantage is there with conducting a gynaecological US outwith of the radiology department?

Answer 6

• Images aren’t stored on same electronic database
  => patient has an incomplete imaging record
  => difficulty for comparison of serial scans

Question 7

What two US techniques can be used to image suspected gynae pathology?

Answer 7

Transabdominal - general abdominal US transducer

Transvaginal - high- frequency transducer

Question 8

A transabdominal and transvaginal US cannot be performed on the same attendance to clinic. TRUE/FALSE?

Answer 8

FALSE

both techniques are used at the same attendance

Question 9

During a transabdominal US, clinians have a quick scan of the upper abdomen. Why may they do this and what are they looking for?

Answer 9

• ensure that there is no hydronephrosis
• detect early ascites
• check pelvic abnormality is not secondary to upper abdominal pathology

Question 10

Why must a patients bladder be FULL on a transabdominal US?

Answer 10

• bladder acts as an “acoustic window”
• distended bladder displaces gas-filled bowel loops out of the pelvis
• bowel gas usually scatters the US beam => poor image quality

Question 11

What are the drawbacks of transabdominal US?

Answer 11

• difficult to obtain good images in obese patients
• difficult if patients have gaseous distension of bowel
• Operator dependent
• difficult to produce same images every time => NOT used to assess response to cancer tx

Question 12

What structures can normally be visualised on a transabdominal US?

Answer 12

Bladder (dark as it is FULL of fluid)
Uterus and endometrial lining (lining is brighter on scan)
Ovary or vagina may also be seen on scan

Question 13

What vessels lie in closes proximity to the ovary and therefore act as a landmark on Transabdominal scanning?

Answer 13

External iliac artery and vein

Question 14

Why does transvaginal US need to be closer to the target organ?

Answer 14

• Higher frequency waves => shorter wavelength => dont travel as far
• Higher frequency waves scatter in the body
  => transducer has to be close to the target organ

Question 15

Does a transvaginal US require a full or empty bladder?

Answer 15

Empty

(a full bladder can make the examination uncomfortable).

Question 16

What are the disadvantages of a TVUS?

Answer 16

• More invasive
• Not suitable for individuals who have not been sexually active
• may not depict full extent of large pelvic masses

Question 17

In what situations is CT used to investigate suspected gynaecological pathology?

Answer 17

• 2nd line investigation (after US) in acute abdominal pain
• Surgical complications – e.g.small bowel obstruction secondary to adhesions, post-op collections/abscesses etc.
• Stage Gynaecological malignancy
• Assess response to treatment (chemo+/-radio)

Question 18

What are the main disadvantages of CT scanning?

Answer 18

• High radiation dose (160 CXRs)
• significant dose to ovaries
  => used sparingly in children and patients of reproductive age
• MR is better at providing good tissue resolution of pelvic organs

Question 19

What type of energy is used in an MRI and is this harmful?

Answer 19

radiofrequency energy rather than ionising

=> NOT harmful

Question 20

Why are different MRI sequences used in scans?

Answer 20

• define the tissue composition in the body area being
  scanned
• e.g. T1 fat suppression scan can be used to check for dermoid cyst

T2 - Fluid = bright white
T1 - Blood, protein and fat = white

Question 21

What are the main disadvantages of MRI?

Answer 21

• Time-consuming
• Poor depiction certain orans (e.g. lungs)
• Not tolerated claustrophobic
• Contra-indicated - pacemakers, metallic heart valves, cochlear implants etc

Question 22

When are MRI scans normally indicated to investigate gynaecological patients?

Answer 22

• Cancer staging – esp. cervical cancer
• Further analysis of adnexal and uterine masses
• Evaluation of sub-fertility – are there are contributory anatomical variations in the pt?
• MRI pituitary gland if suspected prolactinoma

Question 23

How can endometriosis show characteristic signs on MRI?

Answer 23

• 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)

Question 24

What are dermoid cysts and what do they contain?

Answer 24

Dermoid cysts = also known as ovarian teratomas

• contain tissue derived from ectoderm, mesoderm and endoderm
• contain a mixture of tissues, but most contain a large amount of fat

Question 25

What scan is used to assess tubal patency with radio-opaque dye? And how long does this procedure take?

Answer 25

• Hysterosalpingography
• X-ray screening procedure – real-time imaging
• Procedure usually completed ~3-5 minutes
• Cervix is cannulated
• radiopaque contrast instilled to fill the uterine cavity and spill out of fallopian tubes

Question 26

How does ovarian cancer spread ?

Answer 26

Disseminates by peritoneal spread

Question 27

What causes the abdomen to be distended in ovarian cancer?

Answer 27

ascites - fluid round the abdomen

Question 28

What other collection of fluid is common in ovarian cancer?

Answer 28

Malignant pleural effusions can result from spread of disease via pleuro-peritoneal communications
L
Initial diagnosis is often made by ultrasound (ovarian masses)
CT scanning is the usual method used for radiological staging

Question 29

What type of spread is UNCOMMON in ovarian cancer?

Answer 29

• Lymph node mets
• Lung mets
• hepatic mets

LESS common - usually patients displaying these have cancers with the BRCA1 mutation

Question 30

What scans are used to diagnose and stage ovarian cancer?

Answer 30

Diagnosis - ultrasound (ovarian masses)

Staging - CT scan

Question 31

What spread of disease do you need to look out for in cervical cancer?

Answer 31

• Spread into the parametrium (adj. to cervix)
• Extension into the vagina
• Infiltration of adjacent organs: rectum, ureters, urinary bladder
• Metastases to regional lymph nodes (internal iliac and obturator)

Question 32

What scans are used to determine the extent of local disease and distant disease in cervical cancer?

Answer 32

Local - MRI

Distant - CT

Question 33

What women are most likely to develop endometrial cancer and what signs of this can be picked up on TVUS?

Answer 33

• Post menopausal women (complaining of bleeding)
• abnormally thickened endometrium
  PMB

Question 34

What scans are used to assess local and distant disease in Endometrial cancer?

Answer 34

MRI used for degree of myometrial invasion

CT scan used to look for distant metastases

Question 35

Why may MRI be contraindicated or not work for patients with endometrial cancer?

Answer 35

Many patients with endometrial carcinoma are obese

=> may be too large for the narrow bore of MR scanners