Ultrasound Quiz 6: Remember The Renal Pelvis

Question 1:

You are seeing a patient for urination problems. You perform an ultrasound. What do you see?

Yes! This ultrasound is showing hydronephrosis.
Remember that a dilated renal pelvis can help you distinguish hydronephrosis from other conditions.

Hydronephrosis is the dilatation of the renal calyces and pelvis due to an accumulation of fluid. Notably, a dilated renal pelvis can help you distinguish hydronephrosis from other conditions.
Remember that fluid is anechoic (black), so here we have fluid accumulation in the pelvis and calyces (center of the kidney)

Question 2:

An ultrasound of the right kidney is performed. Your attending comes by and asks you what is the hyperechoic structure in the center of the kidney. You reply:

It's the renal pelvis and calyces.

Calcifications - the patient has renal colic

Inflamed tissue from a pyelonephritis

It's the renal pyramids

It's the renal cortex

Cysts - the patient has Polycystic Kidney Disease (PKD)

Yes great job!

The pelvis and calyces are normally hyperechoic (white) on ultrasound. If they're anechoic, it might be a sign of a hydronephrosis as there would be fluid backed up into them.
The pelvis and calyces are found at the center of the kidney. Urine will eventually drain from here into the bladder.
The cortex is hypoechoic (grey). The anechoic (black) spots here are the renal pyramids.

Question 3:

A 49 year old female with a family history of Polycystic Kidney Disease (PKD) is admitted for flank pain and urinary problems. Your attending suspects hydronephrosis and asks you to perform an ultrasound. What should be your next step?

The patient has symptomatic hydronephrosis, so put a catheter in to drain the urine

The patient has PKD so you can confidently rule out hydronephrosis and proceed to treat the patient accordingly.

You cannot tell if the renal pelvis is dilated or not, so you order an MRI to rule out hydronephrosis

That's a normal kidney! The flank pain might be appendicitis though, so you need to prep the OR!

The patient has pyelonephritis and needs antibiotics only.

Great job! The patient here has Polycystic Kidney Disease (PKD). However, we still cannot rule out hydronephrosis. The key way to do so on ultrasound is to look for a dilated renal pelvis, which would inform you that there is hydronephrosis. This can be quite tricky to do in this case, which is why ordering an MRI scan can help you visualize the amount of fluid in the renal pelvis.
Check out this case here for more info! https://www.kidney-international.org/article/S0085-2538(15)53909-4/fulltext

The patient here has Polycystic Kidney Disease (PKD). However, we still cannot rule out hydronephrosis. The key way to do so on ultrasound is to look for a dilated renal pelvis, which would inform you that there is hydronephrosis. This can be quite tricky to do in this case, which is why ordering an MRI scan can help you visualize the amount of fluid in the renal pelvis.
Check out this case here for more info! https://www.kidney-international.org/article/S0085-2538(15)53909-4/fulltext