Genitourinary CAS

Question 1

what is the gold standard imaging for urinary tract stones and explain why.

what would you look for

Answer 1

Non Contrast CT scan

Can see exactly where it’s blocked and other organs involved

Can also see if there’s hydronephrosis (swelling of the kidney due to back pressure)

You can also see peinephric fat stranding

Question 2

what is the summary of the clinical manifestation of ureteric colic

Answer 2

Svere colicky abdominal pain

Renal angle tenderness radiating to the groin including penile tip/lower urinary tract symptoms

Question 3

what are the 3 locations where ureteric stones are likely to be found

Answer 3

Plevoureteric junction

Sacroiliacl joint over the common illiac arteries

Vesicoureteric junction

Question 4

what size of stone can pass by themselves and what requires management

Answer 4

Stones smaller than 5mm can pass by themselves

Larger ones need management like:

• Stenting
• Shockwave Lithiotripsy

Question 5

why is Non-Contrast CT considered the best image modelaity of choice for stones and why aren’t X-rays or USS considered

Answer 5

Question 6

what does this image show?

Answer 6

Large bowel bostruction at arrows with dialtation proximal to site of obstruction

Question 7

what are the causes of bowel obstruction?

Answer 7

Small bowel: adhesions and hernia

Large: cancer, diverticular and volvulus

Can also seperate into Intraluminal, mural and extramural

Question 8

what are the clinical manifestation of bowel obstruction

Answer 8

Symptoms:

• Abdo pain and bloating
• Nausea and vomiting
• Complete constipation
• Overflow diarrhoea as only liquid stool can pass and not solid ones

Signs:

• Abdo distention
• tenderness and guarding
• Tinkling or absent bowel sounds

Question 9

what imaging modality is best for bowel obstruction?

what about x-rays?

Answer 9

NC- CT:

• High sensitivity and specificity
• Can see site, severity and cause of bowel obstruction

AX -rays:

• Cheap and easily accessbile
• But only shows dilatation, 3, 6 , 9
• Can be erect or supine.
• Erect AXR can be used to show fluid level due to the straight lines seen

Question 10

what are the causes of portal hypertension

Answer 10

Pre-hepatic

Hepatic

• Cirrhosis leads to increased pressure in the portal venous system
• and is the most common form of ascites

Post-hepatic

Question 11

what is portal hypertension

Answer 11

This occurs when pressure is above 12mmHg (normal is 6mmHg).

Blood back up in the systemic veins and leading to decreased flow to the liver

Decreased liver function and detoxifying capacity

Question 12

what are the 3 main sites of anastomoses in the portal-systemic venous network

Answer 12

Oesophageal – Between the oesophageal branch of the left gastric vein and the oesophageal tributaries to the azygous system.

Rectal – Between the superior rectal vein and the inferior rectal veins.

Retroperitoneal – Between the portal tributaries of the mesenteric veins and the retroperitoneal veins.

Paraumbilical – Between the portal veins of the liver and the veins of the anterior abdominal wall.

Question 13

what are the features of portal hypertension. Give clincial vignette

Answer 13

Ascites

Bleeding at varices

Caput Medusae

Diminished Liver function

Enlarged spleen

Question 14

if you suspect portal hypertension, what imaging can you order and justify

Answer 14

USS (doppler) to look for liver cirrhosis/nodules and flow in portal vein

CT/MRI (with contrast for vessels) to see:

• ascites
• cirrhosis
• IVC dilatation
• looking for small Hepatocarcinomas

Fibroscan for cirrhosis and liver fibrosis