Lesson 4B (Part 4) Flashcards
Nephrolithiasis
Renal calculi
Who is more affected by nephrolithiasis?
Caucasian men with increasing age
What are nephrolithiasis composed of?
Calcium
- 60-80%
What are predisposing conditions of nephrolithiasis? (5)
- Dehydration
- Urinary stasis
- Hyperuricemia
- Hyperparathyroidism
- Hypercalciuria
What is the cause of nephrolithiasis?
No cause
- if not obstructed its usually asymptomatic
Where can migrating calculus cause? (2)
- Infundibular
- UPJ obstruction
- stones may pass into the ureter and lodge in three areas of ureteric narrowing
What are symptoms of calculi?
Flank pain
What percent do stones <5mm pass spontaneously?
80%
What percent of patients have flank pain due to calculi?
77-93%
What are the 3 areas of ureteric narrowing?
- UPJ just past the ureteropelvic junction
- Where the ureter crosses the iliac vessels
- UVJ at the ureterovesicular junction
What accounts of ureteric narrowing?
Small diameter (1-5mm) of UVJ
What are the modalities that can identify calculi? (5)
- Plain x-ray films
- Tomography
- Intravenous urography
- Ultrasound
- high sensitivity *** - Unenhanced CT
- used if US is unable to detect size and location of stones in patients with severe pain or cant see due to gas
What are the sonographic findings of calculi?
Echogenic foci with sharp distal acoustic shadowing
- twinkle artifact
What percent of stones have the twinkling artifact?
83%
What are other possibilities that can mimic calculi? (5)
- Intrarenal gas
- Renal artery calcification
- Sloughed papilla
- Pyelitis
- Ureteric stent
What do you want tin order to see a twinkle artifact?
A high PRF
- high gain
What might be hard to see due to bowel gas and deep retroperitoneal position?
Ureteral calculi
Hydroureter
A dilated ureter will be seen as a tubular hypoechoic structure entering the bladder obliquely
What may be seen on either side of the stone?
Anechoic ureter
What does obstructing ureteral calculus cause?
Hydronephrosis of the collecting system
What happens with hydronephrosis of collecting system?
Urine is being produced but cannot flow from the kidney to the bladder
What can hydronephrosis be confused with?
Multiple parapelvic cysts
- which would not connect to the pelvis
- they need to be connected
What are the S/S of hydronephrosis? (4)
- Flank pain
- Hematuria
- Fever
- Leukocytosis
What could potentially cause hydronephrosis? (8)
- Stasis of urine
- Infection
- Tumor extension from the bladder, ureter or kidney
- Thrombus
- A kink in the UPJ
- An enlarged prostate gland in men
- which can be due to BPH or prostatitis - Pregnancy
- causes a compression due to a growing fetus - A narrowing of the ureter from an injury or birth defect
What is grade 1 hydronephrosis?
Small fluid filled separation of renal pelvis
What is grade 2 hydronephrosis?
Dilation of some but not all calyces
What is grade 3 hydronephrosis?
Marked dilatation of renal pelvis and all calyces
- an echogenic line separates the collecting system from the parenchyma
What is grade 4 hydronephrosis?
Prominent dilatation of the collecting system
- cortical thinning
- unable to separate the collecting system and the parenchyma
