Image Based Question-71138

A 52-year-old woman presented with gross haematuria associated with right loin pain for 3 days. On physical examination, she was tender over the right loin region but was afebrile.

Blood tests were essentially normal. A KUB was performed as an initial investigation followed by an IVU a few days later .What can be the most possible diagnosis?

A. Renal Infarct

B. Renal Calculus

C. Ureteric Calculus

D. Renal Carcinoma

Correct Answer » B Explanation

Ans:B. Renal Calculus

Image shows:

• Fig.a. Coned KUB shows radioopacities (arrows) over the left renal area which may represent renal stones.

• Fig.b A tomogram obtained during an IVU shows filling defects (arrows) in the left upper pole calyx and left renal pelvis corresponding to the opacities seen on the KUB.

• This supports the diagnosis of left renal calculi. Note that the stones appear radiolucent against a background of contrast. Also note the clubbing of the adjacent minor renal calyces (arrowheads).

RENAL CALCULUS

• Renal calculus is a common cause of haematuria, particularly in the presence of loin pain.

• Renal calculi are composed of crystals and/or aggregated with proteins.

• The crystal may contain calcium or magnesium oxalate/phosphate (which are radio-opaque and found in the majority of stones) or uric acid/ xanthine (which are not radio-opaque). As a result of this variable composition, the majority (~90%) of renal stones are radio-opaque, hence a KUB is useful as the initial investigation in a patient with suspected urinary calculus.

IVU is the key imaging modality for the diagnosis of

1. Suspected urinary tract calculus
2. Radio-lucent calculus which is not visualized on KUB
3. Ureteric calculus which may not be demonstrated by ultrasound.

Information on IVU which is helpful in management of patients with renal stone include:

1. Size of renal stones – stones
2. Coexisting ureteric obstruction – extracorporeal shock wave lithotripsy (ESWL) may not be possible since stone fragments cannot pass down the ureter
3. Associated renal cortical scarring.

• If a patient is allergic to intravenous contrast medium, ultrasound is a good alternative imaging modality for diagnosis