IOD GU Imaging

Question 1

CP Urinary tract calculi?

Answer 1

Severe loin to groin pain
Haematuria
Vomiting
May be known history of renal calculi
male-2:1

Question 2

when is a calculi less likely?

Answer 2

No haematuria
Other symptoms eg change in bowel habit
If there is fever/ infective symptoms/ raised inflammatory markers, simple calculi are also less likely, but:
always consider whether there could be an infected obstructed system as this requires urgent decompression (nephrostomy)

Question 3

which modality?

Answer 3

Abdominal x-ray: although large calculi are sometimes visible on AXR, their use is no longer indicated in this clinical scenario
CT KUB: this is now the first line investigation in most cases of suspected calculi
Ultrasound: this is approximately 50-80% sensitive for renal calculi. The benefit is that it does not use ionising radiation; its main role is in follow up of patients with known calculi

Question 4

Pros vs cons of CT KUB?

Answer 4

This is performed as a low dose, non-contrast examination
Typical dose is approximately 1.5mSv (chest xray= 0.1mSv)

Benefits:
High sensitivity and specificity for calculi
Images the whole urinary tract so can show the number and location of all stones
Low dose reduces exposure to ionising radiation
Non-contrast so safe in patients with renal impairment
Limitations:
Reduced sensitivity for other intra-abdominal pathologies
Certain rare types of renal stone (eg indinavir) are not radio-opaque and therefore not visible on CT

Question 5

What is important to check?

Answer 5

IV use?

Question 6

Obstruction?

Answer 6

Calculi can dislodge from the kidneys and pass down the ureters, where they may get stuck and cause obstruction
The three commonest sites for calculi to obstruct are at the:
pelvi-ureteric junction
pelvic brim
vesico-ureteric junction

Question 7

US for Ut calculi?

Answer 7

Lower sensitivity than CT but can detect renal calculi, particularly if larger (≥5mm)
Appear as bright (echogenic) foci within the kidneys with posterior shadowing

Question 8

Twinkle artefact?

Answer 8

Diff colours at high freq This can be helpful to distinguish calculi from renal sinus fat which also appears bright

Question 9

Hydronephrosis?

Answer 9

Dilatation of the urinary collecting system in the kidney
Due to obstruction of urinary drainage
Depending on the level of the obstruction, may be accompanied by hydroureter
Often causes renal impairment (abnormal U+Es)

Question 10

Causes of hydronephrosis?

Answer 10

Urinary tract calculi
Urinary tract malignancy
Pelvi-ureteric junction stenosis
Extrinsic ureteric compression eg due to pelvic malignancy
Prostatic enlargement causing bladder outflow obstruction
Pregnancy

Question 11

Imaging in hydronephrosis?

Answer 11

Ultrasound is usually first line investigation for suspected urinary tract obstruction
Benefits
Fast study which demonstrates hydronephrosis clearly
No ionising radiation

Limitations
Difficult to visualise ureters so may be unable to determine level and cause of obstruction
If suspecting malignant pathology, CT may be more appropriate to provide more information on extent of disease

Question 12

Normal renal pelvis?

Answer 12

1cm

Question 13

Imaging in testicular torsion?

Answer 13

If there is significant clinical suspicion for torsion, imaging should not delay surgical exploration
this is a surgical emergency

Salvage rates are closely related to time to diagnosis (80% in first 6hrs, falling to 20% after 24hrs)
If imaging is available rapidly and/or there is significant diagnostic uncertainty, ultrasound may be performed
If imaging is normal or equivocal but there is a high clinical suspicion, surgical exploration is still required

Question 14

Imaging in testicular trauma?

Answer 14

Ultrasound is the first line investigation
Potential findings:
Testicular rupture- important diagnosis as requires surgical repair
Intra-testicular haematoma
Haematocele

Question 15

CP of female severe abdominal pain?

Answer 15

preg test
positive-ectopic
negative-others like ovarian torsion

Question 16

Imaging in gynaecological emergencies?

Answer 16

Transvaginal ultrasound (TVUS) is usually first line imaging for suspected gynaecological emergencies
A small ultrasound probe is inserted into the vagina
The proximity of the probe to the pelvic organs results in better image quality and detail
Contra-indications to TVUS:
paediatric patients
virginal status
patient declines
A transabdominal scan with a full bladder can be performed instead in these scenarios

Question 17

bastocoele cyst sign?

Answer 17

ring of fire in US

Question 18

ovarian torsion?

Answer 18

Rotation of the ovary on its vascular pedicle, resulting in impairment of the blood supply
Requires urgent surgical intervention to prevent ovarian necrosis
Imaging features (TVUS is first line):
Ovarian enlargement due to venous/lymphatic engorgement
Reduced vascularity
May be an underlying ovarian lesion eg cyst which acts as a lead point

Question 19

imaging in PM bleeding?

Answer 19

Transvaginal ultrasound is the first line
Can detect endometrial thickening/irregularity and may show disrupted endometrial junction
MRI has an important role in staging endometrial cancer
Technique of choice for evaluating depth of invasion into the myometrium and cervical extension
CT
Reserved for patients with advanced disease to evaluate more extensive pelvic invasion and detect distant metastases

Question 20

What should be seen in a normal MRI?

Answer 20

Junctional zone