Diagnosis of Stones
has become increasingly important technology for the detection of
renal calculi. The sensitivity of ultrasonography is slightly superior
to that of plain abdominal films. The renal calculi are detected
by their marked echogenicity and associated acoustic shadowing.
The minimal size of calculus that are detected or identified is
at least 0.5 cm. with a transducer between 2.25 and 3.5 MHz. Transducers
in the range of 6 - 10 MHz are able to detect renal calculi as small
as 3 mm.
kidney. Longitudinal section of the kidney (yellow arrowheads).
The renal sinus is seen as an echogenic central zone. The cortex
of the kidney is hypoechoic.
ultrasonography is another imaging modality, which offers anatomical
details of anatomical details without exposure to radiation or contrast
material. The protection of the renal calculus is based on the presence
a of highly echogenic focus with posterior acoustic shadowing of
the stone. Renal ultrasonography is a useful screening tool for
the demonstration of renal stones and evaluation of hydronephrosis
in patients with suspected renal calculi. In most institutions,
ultrasound for the detection of renal calculi is useful for patients
where intravenous contrast or radiation is contraindicated. However,
ultrasound is seldom utilized in the initial evaluation of patient
with flank pain.
calculus. Renal ultrasound demonstrating echogenic focus (red
arrow) with an associated acoustical shadow (yellow arrowheads).
Good anatomical detail of the kidney in a short period of time.
No exposure to radiation.
No use of intravenous contrast agents.
Ultrasound is regarded as safe in obstetric patients.
Poor visualization of calcifications or obstructing stones in
of assessment of renal function.
The need for a full bladder to properly visualize stones at the
ureteral vesicle junction (UVJ).
Limited role in the diagnosis of other pathology in the absence
of a ureteral calculus.
FC, Jeffrey RB Jr., Wing VW: Ultrasound versus excretory urography
in evaluating acute flank pain. Radiology 1985; 154(3): 613-616.
IA, Cronan JJ, Breslaw BH, et al: New techniques of ultrasound and
color Doppler in the prospective evaluation of acute renal obstruction.
Do they replace the intravenous urogram? Abdom Imaging 1995; 20(1):
E, Alanen A, Nurmi M: Radiologic diagnosis of renal colic: The role
of plain films, excretory urography and sonography. Eur J Radiol
1990; 11(3): 180-183.
A, Gothlin JH: Ultrasonic diagnosis of ureteral calculi in patients
with acute flank pain. Eur J Radio 1990; 11(2): 87-90.
S, Sindel T, Arslan G, et al: Renal colic: Comparison of spiral
CT, US and IVU in the detection of ureteral calculi. Eur Radiol
1998; 8(2): 212-217.