Bladder ultrasound
Background
- Identification: anechoic (black) fluid within a structure defined by hyperechoic (white) appearing borders
- Bladder volume = length x width x heigth x 0.52
Technique
- Phased array or Curvilinear
- Suprapubic: look both transverse and sagittal
- usually need to turn down far gain 2/2 acoustic enhancement from bladder
- Color over the inferior border can demonstrate ureteral jets
- Twinkle Sign: rapid alternation of color immediately behind a stationary echogenic object, acquiring a false appearance of movement
- Can indicate stone in the UVJ
- Twinkle Sign: rapid alternation of color immediately behind a stationary echogenic object, acquiring a false appearance of movement
- Lack of jet on one side can indicate ureteral obstruction
- Anechoic (black) fluid outside the bladder: Free Fluid
- Look for 'pointy edges:' increases suspicion for fluid not in another structure (cyst, ovary, bowel, etc)
Clinical Uses
- Look for free fluid (abdominal or pelvic)
- Can be used to calculate post void residual non invasively
- Confirm foley placement by visualizing balloon
- Ureteral obstruction
- Nephrolithiasis in the UVJ
- Possible to see ectopic pregnancy
Source
Arch Ital Urol Androl. 2005 Mar;77(1):60-2. Measurements of urinary bladder volume: comparison of five ultrasound calculation methods in volunteers. Dicuio M, Pomara G, Menchini Fabris F, Ales V, Dahlstrand C, Morelli G.