Unit 10- Hydronephrosis (Elie)

What is Hydronephrosis of Urinary Tract Obstruction (UTO)

Dilation of pelvocalyceal system

Interconnected fluid-filled calyces

With UTO what does progressive obstruction do?

• Compresses renal parenchyma

• Compromising renal function

•When renal compromise is suspected, a renal US performed to R/O obstruction of what?

Collecting System

What is this image showing?

Hydronephrosis
Urinary Tract Obstruction (UTO)

What is Grade 1 of Hydronephrosis?

Small fluid-filled separation of renal pelvis “splaying”

What is Grade 2 of Hydronephrosis?

Extension into some but not all major & minor calyces “bear-claw”

What is Grade 3 of Hydronephrosis?

Complete pelvocaliectasis, echogenic line separating collecting system from renal parenchyma

What is Grade 4 of Hydronephrosis?

• Massive dilation of collecting system

• Loss of renal parenchyma

What are these images showing?

A- Grade 1

B- Grade 2

C- Grade 3

D- Grade 4

Grade 1 Hydronephrosis is also called what?

Mild Hydronephrosis

Splaying of calyces indicates hydronephrosis rather than an ________ _____

Extrarenal Pelvis

What grade of hydronephrosis is this?

Grade 2

What is this image showing?

Hydronephrosis Pelvis- Ureter

What are the US findings for Hydronephrosis?

• Dilation of fluid filled renal pelvis & calyces

  • Fluid-filled areas conform anatomically to calyces & renal pelvis

With hydronephrosis where should scan?

• Document level of obstruction

  • Mass or stone identified

While scanning for hydronephrosis, if the bladder is full, the patient should void and what should happen for the rest of the scan?

Kidneys are rescanned to R/O transient hydronephrosis  vs obstruction

What does a sonographer need to differentiate between when scanning?

Hydronephrosis, extrarenal pelvis, and peri/parapelvic cysts

What must be documented when a sonographer differentiates between hydronephrosis, extrarenal pelvis & peri/parapelvic cysts?

• Connection with calyces must be documented

• Evaluation of ureters & bladder must be included

What are the clinical findings for Obstructive Hydronephrosis?

• Renal insufficiency

• Decreased urine output

• HTN

What are the findings for an Acute Obstruction of hydronephrosis?

• Intrarenal RI  increased for 48 – 72 hours

• > 0.7 then returns to normal

• Compare with contralateral side

What is this image showing?

Normal Ureteral Jets

What is this image showing?

Partially obstructed left ureter with decreased flow

What may cause Nonobstructive Hydronephrosis?

• Reflux

• Infection

• Polyuria

• Overhydration

• Post obstruction atrophy

• Pregnancy- usually on right

• Distended bladder =

  • Transient hydronephrosis

US findings for Nonobstructive Hydronephrosis:

Ureteral jets indicate non-obstructive hydronephrosis

Use color Doppler for jets

What can Localized Hydronephrosis be secondary to?

• Strictures

• Calculi

• Focal masses

• Duplex collecting system with ectopic insertion of ureter

What is this image demonstrating?

Localized Hydronephrosis

What are the similar appearing conditions for False-Positive Hydronephrosis?

• Extrarenal pelvis

• Parapelvic cysts

• Reflux

• Multicystic kidney

• Transient diuresis

• Congenital megacalyces

• Papillary necrosis

• Renal artery aneurysm – use color Doppler

• Arteriovenous malformation – use color Doppler

• Duplex collecting system

What are the False- Negative Hydronephrosis?

•Distinction of renal pelvis from dilated calyces

•Polycystic Kidney Disease

•Transient obstructive process

Once obstruction has been ruled out for False Negative Hydronephrosis, what should be considered next?

Renal medical disease as cause of renal dysfunction

What is Pseudohydronephrosis from and what should the sonographer do?

• From over distended urinary bladder

• Have patient urinate, then rescan to check for drainage & change

• Document pre & post void

What are these images showing?

Pseudohydronephrosis