Imaging in Gynaecology

Question 1

What imaging modalities are used in gynaecology?

Answer 1

US, CT, MRI, fluoroscopy (HSG), PET-CT

Question 2

What are the indications for using radiology?

Answer 2

Diagnosis of pelvic pain
Assessment of pelvic pain 
Investigation of abnormal menstrual bleeding
Assessment of postmenopausal bleeding
Investigation of infertility
Interventional radiology

Question 3

Where can US be performed?

Answer 3

Radiology department, gynaecology clinic and some GP practices

Question 4

What are the two types of US used?

Answer 4

Transabdominal and transvaginal

Question 5

How are pelvic organs scanned during a transabdominal US?

Answer 5

Through the anterior pelvic wall

Question 6

Should the upper abdomen be looked at during a transabdominal US?

Answer 6

Yes = look for hydronephrosis, ascites or primary abdominal pathology

Question 7

What preparation is needed for a transabdominal US?

Answer 7

Need a full bladder = urine-distended bladder acts as acoustic window

Question 8

What are the advantages of transabdominal US?

Answer 8

Safe, readily available, no ionising radiation

Question 9

What are the disadvantages of transabdominal US?

Answer 9

Difficult to image obese patients and if there is gaseous bowel
Difficult to produce exactly the same image every time

Question 10

What are some features of transvaginal US?

Answer 10

Higher frequency so shorter wavelength and better spatial resolution but needs to be close to target as more likely to scatter

Question 11

How should the bladder be prepared for a transvaginal US?

Answer 11

Requires empty bladder = uncomfortable if the bladder is full

Question 12

What are the advantages of a transvaginal US?

Answer 12

Excellent depiction of pelvic organs

Question 13

What are the disadvantages of a transvaginal US?

Answer 13

Invasive, not suitable for those who haven’t had sex, may not depict full extent of large pelvic masses

Question 14

What are CT scans used for as a second line investigation?

Answer 14

Often used as second line investigation after US in patients with acute abdominal pain

Question 15

What are some uses of CT in gynaecology?

Answer 15

Can be used to assess post-surgical complications
Useful for staging malignancy (endometrial, ovarian)
Can assess response to treatment after chemotherapy +/- radiotherapy

Question 16

What are the advantages of CT?

Answer 16

Quick, entire chest/abdomen/pelvis can be assessed in one image, can manipulate images to give many different views

Question 17

What are the disadvantages of CT?

Answer 17

High radiation dose, doesn’t provide optimal depiction of different pelvic organs

Question 18

How does MRI create images?

Answer 18

Uses radiofrequency energy rather than ionising radiation = different protocols can be used to define tissue composition in the area being scanned

Question 19

What are the advantages of MRI?

Answer 19

Provides excellent depiction of pelvic organs, no ionising radiation, can give some idea about composition of soft tissue masses

Question 20

What are the disadvantages of MRI?

Answer 20

Time consuming, poor depiction of lung parenchyma, not suitable if claustrophobic

Question 21

What are the contraindications of MRI?

Answer 21

Pacemaker, artificial metal heart valves, nerve stimulators, cochlear implants

Question 22

What are the gynaecological uses of MRI?

Answer 22

Cancer staging = especially cervical
Evaluation of adnexal and uterine masses
Evaluation of patients with subfertility
MRI of pituitary for suspected prolactinoma

Question 23

How is endometriosis diagnosed?

Answer 23

Difficult to diagnose = patients may need diagnostic laparoscopy

Question 24

How is endometriosis recognised on MRI?

Answer 24

Deposits contain altered blood and haemoglobin degradation products = cause characteristic MRI changes

Question 25

How does the altered blood in endometriosis appear on MRI?

Answer 25

Returns high signal on T1 sequences = looks white | Returns low signal on T2 sequences = looks grey

Question 26

How does fat appear on MRI?

Answer 26

Looks white on T1 sequences but appears dark on special fat-suppression sequences

Question 27

What do dermoid cysts contain?

Answer 27

Tissue derived from ectoderm, mesoderm and endoderm = mostly contain fat v=but can contain many types of tissue

Question 28

How is fat imaged?

Answer 28

Has predictable MRI signal characteristics and can also use CT, but difficult to perceive on US

Question 29

What is a hysterosalpingography (HSG)?

Answer 29

X-ray screening procedure = real-time imaging, usually takes 3-5mins

Question 30

What is an HSG used for?

Answer 30

Assessment of tubal patency in suspected infertility and assessment of uterine cavity

Question 31

How is an HSG carried out?

Answer 31

Cervix cannulated and radiopaque contrast instilled to fill uterine cavity

Question 32

What is done before contrast is instilled during an HSG?

Answer 32

A scout "control" film is obtained just before

Question 33

When are images captured during an HSG?

Answer 33

Once contrast is instilled = series of images captured as contrast fills uterine cavity, then into fallopian tubes and spills into peritoneal cavity

Question 34

How is cancer staged?

Answer 34

Using TMN system

Question 35

What is the purpose of the pre-treatment scan for cancer?

Answer 35

Serves as baseline so subsequent scans can be used to assess treatment response

Question 36

How does ovarian cancer spread?

Answer 36

Disseminates by peritoneal spread

Question 37

What extra-ovarian features are common in ovarian cancer?

Answer 37

Ascites, omental and peritoneal nodules are common

Question 38

How do malignant pleural effusions occur in ovarian cancer?

Answer 38

Result from spread of disease via pleuro-peritoneal communications

Question 39

Are lymph node, lung and liver metastases common in ovarian cancer?

Answer 39

No = tend to be seen in patients in whom disease behaviour has been modulated by chemo or in cancers with BRCA1 mutation

Question 40

How is the initial diagnosis of ovarian cancer made?

Answer 40

Using US

Question 41

How is ovarian cancer staged?

Answer 41

CT usually used for radiological staging

Question 42

What must be determined when when staging cervical cancer?

Answer 42

Presence of = spread into parametrium, extensions into vagina, infiltration of adjacent organs, metastases to regional lymph nodes

Question 43

What is used for imaging cervical cancer?

Answer 43

MRI (esp T2) is better than CT for local disease | CT used for determining presence of distant metastases

Question 44

What modality is best for diagnosing endometrial cancer?

Answer 44

Transvaginal US = best for establishing abnormally thickened endometrium

Question 45

What are MRI scans used for in endometrial cancer?

Answer 45

Assessing degree of myometrial invasion

Question 46

Why is there difficulty using MRI to image endometrial cancer?

Answer 46

Many patients obese so are too large for narrow MRI bore

Question 47

What are CT scans used for in endometrial cancer?

Answer 47

Used to find distant metastases and pulmonary metastases