L14,15 Radiology of kidneys, male and female pelvis

Question 1

When should you use xr vs IVU vs Ultrasound?

Answer 1

1. XR: cheap, only finds radio opaque stones- got Ca, not non radio opaque : uric acid crystals
2. IVU: contrast injected XR- helps to see blockages but not what the blockage is . Now usually not done
3. US: preferred as no radiation- good for pregnancy- puberty. However harder if patient has high fat, wriggly.

Useful for renal stones, obstruction, renal mass and bladder lesions but cannot assess ureters.

Question 2

Where is the ureter running

Answer 2

Along the TP of lower vertebrae until L5 before curving out

Question 3

When should you use CT vs MRI - what do they pick up well

Answer 3

1. CT is more accurate, used to assess soft tissues, fluid and calcification
   - But Expensive and significant radiation.
   - May need IV contrast but useful for stones in the ureter, tumour, trauma and infection.
   - Less perfused = less bright
2. MRI is excellent for soft tissues and fluid and has no radiation
   - But expensive and longer scan time by 30-45 min for someone in pain.
   - Useful for soft tissue abnormality, renal tumour, infection

Question 4

What size of the stone corresponds to likelihood of eventual need for intervention

Answer 4

< 2mm: 3%
3mm: 14%
4-6 mm: 50%
>6 mm: 99%

This means need follow up rather than sending back home for them to pass the stone.
Intervention is stents/catheters, tubes to pull the stone out.
Stones are common in NZ due to dehydration, can lead to urinary tract infection.

Question 5

What mode of scan is done for women’s pelvis - same basic modes done for males prostate, scrotum and bladder

Answer 5

Ultrasound: Transabdominal, with a full bladder which becomes the window.
Or Transvaginal: more superior images and more comfortable, scanning with a probe inside the vagina.
Choice is based on culturally appropriate

MRI if there is malignancy/ tissue diagnosis

Question 6

Why would there be fluid in the pouch of douglas

Answer 6

1. It could be fluid from the ovary after ovulation
2. It could be menstrual fluid
3. However if pregnant could be ectopic pregnancy

Question 7

What does polycystic ovary look like and what is it caused by

Answer 7

Due to complicated feedback disorder, signal for ovulation doesn’t come so follicles mature but don’t leave the ovary. The ovary gets gradually bigger due to more follicles rising up.

Question 8

How can female infertility be shown radiographically

Answer 8

HSG- insertion of dye into the uterus via cannula where if the fallopian tubes are not patent or the fimbrae blocked then there will be no spillage at the fimbrae.
This is associated with pelvic inflammatory disease.

Question 9

What to look for when US the testis - acute scrotum pain

Answer 9

• Testicular torsion: lack of blood flow to one testis
• Epididymitis: swollen, lots of blood flow caused by UTI or STI in adults
  or Streptococcus or Ecoli in children
  -Tumour: mass in the testis- can lead to lung metastases.

Question 10

How is the prostate imaged

• also look for the bladder to check if emptying well using US

Answer 10

US:
Transabdominal: looking through the bladder from the outsi
Trans-rectal: probe in the rectum
MRI- multi parametric:
1. Normal MRI: anatomy.
2. Spectroscopy: analyses the type of tissue
3. DCE: dynamic contrast enhanced
4. DWI: Diffusion weighted imaging.
Can see what the tissue is doing and target site for biopsy. help to differentiate between BH or cancer