have multiple ways to look at kidney stones.
The method often depends on the severity of the
problem, the type of stone, and the presence or
absence of symptoms.
of the mid to lower abdomen will include the
kidneys, ureter and bladder. Xrays work by
passing low doses of radiation through the patient's
body onto a photographic negative. When xrays
pass through soft body tissues, they hit the film
and cause it to turn black (exposure). When a
calcium stone or bone (which is also made of
calcium) is present the xray cannot pass through and
no exposure occurs. The stone(s) and bones
will appear white. This technique can only
detect stones which contain calcium. It will
miss pure uric acid or indinavir stones.
Xrays can be done quickly and cheaply and are a
quick, inexpensive, and useful technique for
monitoring growth of a kidney stone.
performed by passing a probe over the kidneys,
ureters, and bladder. Sound waves are emitted
from the probe and are integrated into an image of
the urinary system that can be seen on a television
screen. This test can detect both calcium and
non-calcium types of stones. It often is not a
good test to find a stone that is suddenly passing
from the kidney through the ureter on its way to the
bladder. This is the time when stones hurt the
most and cause people to seek immediate emergency
medical assistance. If the stone has been
lodged in the ureter for some time, then it can
detect obstruction. In this situation the
ureter is abnormally dilated. It is used by
some for routine monitoring of new stones or growth
of old stones. It has the benefit of no radiation.
Tomography (CT or CAT Scan):
This is one of
the best methods to detect kidney stones, especially
when someone comes to the emergency room with severe
pain (colic) due to a passing stone. It is
more sensitive than ultrasound or xray. It is
performed by placing the patient in an xray tube
that creates several images of the kidneys, ureter,
and bladder. It can detect both calcium and
non-calcium stone. Although it may sometimes
miss crixivan/indinavir stones. It is more
expensive than an xray and requires more radiation.
Since it scans many organs, it can sometimes detect
non stone causes of severe pain. (View
This is one of
the older techniques for detecting kidney stone and
still sometimes used. A special dye is
injected into a vein. Then xrays are taken of
mid to lower abdomen. If a stone is present, a
filling defect will be seen on the xray images.
It is very useful for detecting stones in the ureter,
especially if not seen by CT scan. This
sometimes happens when the ureter is
dilated/obstructed but no stone is seen. One
disadvantage is that the injected dye can cause
allergic reactions, usually temporary kidney damage,
and symptoms including nausea. If the patient
has kidney disease other than stones, sometimes it
is better to perform a Retrograde
In this test, a catheter is placed into the bladder
and the dye is injected to visualize the bladder and
ureters for stones. This technique avoids absorption
of the dye outside of the urinary tract.
CT urography is a
combination of CT and IVP. An injection of
intravenous dye is given which outlines the parts of
the kidney, ureterers, and bladder where urine
collects. The images are viewed with a CT
scanner. Traditional CT images are also generated.
This test is particularly helpful as a step in the
evaluation for blood in the urine (hematuria).
It can show causes other than just stones. It
is particularly useful in the evaluation of a kidney
(renal) diverticulum. This is a pouch that
develops inside the kidney. Kidney stones and
infections can form inside this pouch. It can
also be associated with pain.