Imaging in Obs & Gynae Flashcards

1
Q

Use of imaging in Obs and Gynae

A

Confirm or refute a provisional diagnosis
Determine the extent of disease
Assess response to treatment

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2
Q

Most common imaging method used in Obs and gyane

A

Ultrasound

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3
Q

Other imaging methods used in obs and gynae

A

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

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4
Q

Indications for using radiology?

A

Diagnosis of pelvic pain – cause?

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

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5
Q

Benefits of US

A

Relatively cheap
Safe – no ionising radiation
Provides very good definition of different pelvic organs
Can be used in the clinic as an adjunct to pelvic examination

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6
Q

What are the two main ultrasound techniques used?

A

TRANSABDOMINAL - first line
TRANSVAGINAL - well tolerated

Often both techniques are used at the same time

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7
Q

What is good practice during a trans-abdominal ultrasound?

A

To perform a brief assessment of the upper abdomen in order to:

  • ensure that there is no hydronephrosis
  • detect early ascites
  • ensure that the pelvic abnormality is not secondary to upper abdominal pathology
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8
Q

Why must the patient have a full bladder during US?

A

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)

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9
Q

Advantages of trans-abdominal US

A

Safe
Readily available
No ionising radiation and therefore ideal for children and women of reproductive age

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10
Q

Disadvantages of US

A

difficult to obtain good images in obese patients and in patients where there is gaseous distension of the bowel

Operator dependent

It is difficult to produce exactly the same images every time the patient attends and this means ultrasound is not often used for assessing the response to cancer treatment

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11
Q

What is an important landmark to note during TA US

A

iliac artery and vein

It will help locate the ovaries

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12
Q

Trans Vaginal scan

A

Probe goes in much closer proximity to organs of interest so the view is better

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13
Q

Patient needs a full badder for TV US - True or False

A

False

Full bladder is uncomfortable for patient during TV scan

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14
Q

Advantages of TV scan

A

Good depiction of pelvic organs

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15
Q

Disadvantages of TV scan

A

More invasive procedure
Not suitable for individuals who have not been sexually active
Can sometimes just demonstrate “the tip of the iceberg” and may not depict the full extent of large pelvic masses (ideally transvaginal scan should follow a transabdominal scan which allows better overview)

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16
Q

What is the second-line investigation in patients with acute abdo pain?

A

CT scan

17
Q

Uses of CT scan

A

Assess post-surgical complications – e.g.small bowel obstruction secondary to adhesions, post-operative collections/abscesses etc.

Staging of gynaecological malignancy, especially ovarian and endometrial cancers

Assessing response to treatment in patients after chemotherapy +/- radiotherapy

18
Q

Advantages of CT scan

A

Quick

The entire chest abdomen and pelvis can be assessed on one scan

Modern multiple detector row (“multislice”) scanners produce very thin slices and images can be manipulated to produce coronal and sagittal reformats, as well as the axial source images

19
Q

Disadvantages of CT scanning

A

High radiation dose (equivalent to about 160 chest x-rays) with a significant dose delivered to the ovaries

Therefore used sparingly in children and patients of reproductive age

Does not provide optimal depiction of different pelvic organs (MR is better at providing good tissue resolution)

20
Q

How does MRI work?

A

Uses radiofrequency energy rather than ionising radiation
It is possible to alter the time between transmitting the RF signal and receiving the RF signal from the patient and this leads to scans with different characteristics – e.g. T1- and T2-weighted scans

T2 - more fluid sensitive - organs or structures containing fluid will be bright

T1 - Fat, protein, blood appear dark

21
Q

Advantages of MRI

A

Provides an excellent depiction of pelvic organs

No ionising radiation and is therefore suitable for children and women of reproductive age

Can give some idea about the composition of soft tissue masses – e.g. do they contain fluid, fat, blood etc ?

22
Q

MRI is safe during pregnancy except during ____?

A

1st trimester

23
Q

Disadvantages of MRI

A

Time-consuming

Poor depiction of lung parenchyma – a CT scan should be performed if there is query about pulmonary metastases

Not tolerated if patients have claustrophobia

Contra-indicated in patients with: pacemakers, many artificial metallic heart valves, nerve stimulators, cochlear implants etc etc.

24
Q

Uses of MRI in Gynae patients

A

Cancer staging – especially cervical cancer

Further evaluation and characterisation of adnexal and uterine masses, where pelvic ultrasound or other imaging have not provided a diagnosis

Evaluation of patients with sub-fertility – are there are contributory anatomical variations?

MR of the pituitary gland is performed in patients with suspected prolactinoma

25
Q

Endometriosis and imaging

A

Endometriosis contains altered blood and Hb degradation products - cause characteristic MR signal changes

26
Q

What is the appearance of blood from endometriosis on T1?

A

Bright

Note: Rule out other things that cause a bright appearance on T1 (ex. fat)
- T1 fat suppression to be done

27
Q

What is the appearance of blood from endometriosis on T2?

A

Grey

28
Q

Name the pathology that appears as an admixture of different tissue types and a a large amount of fat

A

Dermoid cyst

29
Q

Describe the uses of hysertosalpingography

A

For assessment of tubal patency in patients with infertility
Can also assess outline of uterine cavity
Procedure usually completed ~3-5 minutes
Cervix is cannulated and radiopaque contrast instilled to fill the uterine cavity

30
Q

How does ovarian cancer spread?

A

Peritoneal spread
Ascites, omental and peritoneal nodules are common. Sub-diaphragmatic deposits and deposits on the surface of the liver are also seen
Malignant pleural effusions can result from spread of disease via pleuro-peritoneal communications

31
Q

List the less common metastases of ovarian cancer

A

lymph node metastases
Lung metastases
Hepatic metastases

32
Q

How is initial diagnosis of ovarian cancer made?

A

US

33
Q

What is the usual method for radiological scanning of ovarian cancer?

A

CT

34
Q

When staging cervical cancer, which locations of spread are you looking for/

A

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

35
Q

Which imaging modality is used for scanning cervical cancer?

A

MR - local disease
CT - distant metastases
(e.g. lung, para-aortic and mediastinal lymphadenopathy)

36
Q

Which imaging modality used to establish thickened endometrium in PMB?

A

TV US

37
Q

Imaging modality to determine degree of invasion in endometrial cancer

A

MR

38
Q

Imaging modality to look for distal nodal and pulmonary metastases

A

CT