Transcript Imaging in Urology

Imaging in Urology
Imaging Modalities
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Plain film imaging (Radiography)
Plain film of the abdomen (KUB)
Urography
Ultrasonography
Computed tomography
Magnetic resonance imaging
Radionuclide imaging
Plain Film Imaging
• Uses x-rays to develop an image on a piece of
film based on the amount of energy that
passes through the object between the source
and the film plate
– Tissues of the body and foreign or organic
materials that may be found within the body
absorb different amounts of radiation to create a
readable image
– Contras media can be used for a more precise
evaluation of the urinary tract
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
Plain Film of the Abdomen (KUB)
• The kidneys-ureters-bladder (KUB) is often the
first imaging study performed to visualize the
abdomen and urinary tract
– The film is taken with the patient supine and
should include the entire abdomen from the base
of the sternum to the pubic symphisis
– Can show bony abnormalities, calcification and
large soft tissue masses
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
Urography
• Involves instillation of contrast material to
better visualize the collecting or lumenal
structures of the kidneys, ureters, bladder, and
urethra
– This can be done after IV injection or direct
instillation into the urinary tract
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Intravenous urography
Cystography
Voiding cystourethroography
Retrograde urethrography
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
Intravenous Urography
• IVU/ intravenous pyelogram is the classic
modality of imaging the entire urethelial tract
from pyelocalyceal system trhough the ureters
and bladder
– Excellent for indentifying small urethelial lesions
as well as the severity of obstruction from calculi
– Provides anatomical and qualitative functional
information about the kidneys
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
Cystography
• Permits imaging of an opacified urinary
bladder after retrograde instillation of contrast
media through a urethral or suprapubic
catheter
– Imaging is performed to demonstrate a suspected
urine leak, either from traumatic bladder rupture
or after bladder surgery
– Can also demonstrate a presence of a fistula
between the bladder and vagina or to characterize
bladder diverticuli
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
Voiding Cystourethrography
• Can be used to evaluate for abnormal
anatomy and function of the lower urinary
tract in both children and adults
– Similar to the cystogram, instillation of contrast
media into the bladder through a urethral
cahteter is also employed
– After full distention of the bladder, the patient is
instructed to void either after removing the
catheter or around the catheter
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
Retrograde Urethrography
• Complete evaluation of the urethra includes
both antegrade and retrograde urethrography
– Allows visualization of the anterior male urethra
– Used for evaluating a suspected traumatic urethral
injury or urethral stricture
– Can also be useful for diagnosis of a urethral
diverticulum in females
Potts, J. (2004). Essential Urology: A Guide to Clinical Practice. Humana Press Inc.
MRI
• Can be generally used in place of a CT scan
when renal insufficiency or contrast allergy
prohibits the use of CT scan
• The process by which the protons realign
themselves with the magnetic field is referred
to as relaxation. The protons undergo 2 types
of relaxation: T1 (or longitudinal) relaxation
and T2 (or transverse) relaxation
MRI
• In T1-weighted images (emphasizing the difference in
T1 relaxation times between different tissues),
water-containing structures are dark. T1-weighted
images do not show good contrast between normal
and abnormal tissues. However, they do
demonstrate excellent anatomic detail.
• T2-weighted images emphasize the difference in T2
relaxation times between different tissues. Because
water is bright in these images, T2-weighted images
provide excellent contrast between normal and
abnormal tissues, although with less anatomic detail
than T1-weighted images
MRI
CT Scan
• Study of choice for the general imaging of the kidney
and ureter
• used to create cross-sectional images of structures in
the body. In this procedure, x-rays are taken from
many different angles and processed through a
computer to produce a three-dimensional (3-D)
image
• Uptake of contrast by renal parenchyma during
nephrogram phase provides rough estimate of
kidney function
• Useful when renal of ureteral malginancy is
suspected
CT Scan
• often used examine structures
in the abdomen and pelvis
(reproductive organs, liver,
pancreas, gallbladder, spleen
and intestines). CAT Scans are
a diagnostic tool that
urologists use to detect and
diagnose: recurrent urinary
tract infections, sources of
blood in the urine (hematuria),
kidney stones, renal cysts and
masses. Moreover, it can help
urologists rule out prostate,
bladder and renal cancers
Nuclear Medicine
• uses the radiation released by radionuclides (called
nuclear decay) to produce images
• A radionuclide, usually technetium-99m, is combined
with different stable, metabolically active
compounds to form a radiopharmaceutical that
localizes to a particular anatomic or diseased
structure (target tissue).
• tracer goes to the target organ and can then be
imaged with a gamma camera, which takes pictures
of the radiation photons emitted by the radioactive
tracer