Hematuria / Renal Stone

What is the differential for hematuria?
  • Trauma
  • Renal calculi
  • Renal cancer
  • Bladder stone or cancer
  • Acute glomerulonephritis
Imaging workup of renal cancer and trauma is discussed elsewhere.

Urine analysis is diagnostic showing red cells and red cell casts in acute glomerulonephritis

What is the common cause for painful hematuria?
  • Calculi in GU tract

What is the common cause for painless hematuria?

  • Renal cancer

What are useful imaging modalities to investigate renal stones?

  • KUB plain film
  • Non contrast CT abdomen
  • Ultrasound

KUB Plain film

Kidney Stone

Abdominal radiograph of the kidneys, ureter and bladder (KUB)
  • Allows for the evaluation of urinary tract stones.
  • Ninety percent or more of urinary-tract stones are radio-opaque.
  • The degree of opacity varies depending upon the composition of stone (calcium content of the stone).
  • Uric acid stones (8%) are radiolucent.
  • Visibility of stones depends not only on the degree of opacity, but also on their sizes and positions relative to other abdominal structures.
  • An opaque stone needs to be approximately 2mm in its largest diameter to be visible on an abdominal film.
  • Poor sensitivity for ureteral stones.

Non-contrast helical computed tomography of the abdomen (NCHCT)

  • Greater sensitivity than KUB for ureteral stones
  • Most sensitive and specific (95-97% and 96-97% respectively)
  • Because abdomen and pelvis are scanned in one to two breaths, virtually eliminates the problem of respiratory motion
  • Can be performed quickly, eliminating potential delays
  • Safe, because eliminates the risk of contrast, which includes allergic reactions and toxicity
  • Detects non-urologic pathology - including appendicitis or ovarian cysts
  • While more expensive than a KUB, comparable to a excretory urography and ultrasound
  • Able to detect all stones regardless of composition, except those associated with indinavir therapy for HIV infections

Bilateral Renal Pelvis Calculi

Arrowheads: There is soft tissue infiltration secondary to extravasations of urine around both renal pelvis.


  • Preferred procedure in pregnant women and in patients allergic to IV contrast.
  • Not dependent on the composition of stones and detects uric-acid stones as well as calcium stones.
  • Stones are seen as highly echogenic foci and often produce distal acoustic shadowing
  • Not always possible to distinguish small stones from arterial calcifications, pericalceal fat, or crystal-laden calceal sub mucosal plaques.
  • Detects hydronephrosis
  • Generally good sensitivity .
  • Ureteral stones are difficult because of overlying gas

Kidney Stone  

US: Lower pole calculus.

Sensitivity, specificity of procedures.













 Utility of imaging procedures

Indicate when you would select each procedure.

Controversy exists over the proper procedure sequence. With the addition of non-contrast helical CTs, some advocate CT as the first-line procedure. However, most physicians continue to utilize plain radiographs of the abdomen (KUB) as the initial screening imaging procedure.