ultrasound investigations of urology

2. The objective examination of a
patient is one of the most important
methods in establishment of a
correct diagnosis, especially, if the
patient is unconscious.
Ultrasound is an imaging
technology that has evolved swiftly
and has come a long way since its
beginnings. It is a commonly used
initial diagnostic imaging modality
as it is rapid, effective, portable,
relatively inexpensive, and causes
no harm to human health.
In the last few decades, there have
been significant technological
improvements in the equipment
as well as the development of
contrast agents that allowed
ultrasound to be even more widely
adopted for urologic imaging.
Ultrasound is an excellent
guidance tool for an array of
urologic interventional procedures
and also has therapeutic
application in the form of high-
intensity focused ultrasound
(HIFU) for tumor ablation.
Introduction

3. An ultrasound exam (or "sonogram") is a painless diagnostic technique that makes use of how sound waves travel
through the body. When sound waves pass through the body, they bounce off tissues and organs in certain ways. The
reflected waves can be used to make images of the organs inside. The sound waves don’t hurt the body, and there’s no
radiation.
The patient lies on the exam table. A clear, water-based gel is put on the skin over the part to be checked. This gel helps
the sound waves go through the body. A hand-held probe ("transducer") is then moved over that part. For prostate
ultrasound exams, a specially designed probe is inserted into the rectum.
There is no risk of radiation. The patient can return to daily tasks right away after the test.
Some exams, such as a bladder scan for residual urine, don’t call for the user to have a lot of experience. Other exams,
such as ultrasound of the kidneys, testicles or prostate, call for the user to have more experience or skill.

6. The kidneys are 2, fist-sized organs found on either side of your mid-section ("retroperitoneum"). The kidneys remove waste
from the blood and make urine. They also balance salts ("electrolytes") in the body, such as sodium and potassium. Hormones
that control blood pressure and red blood cell production are also made in the kidneys.
Renal ultrasound studies can show the size and position of the kidneys.
They can also show if there are:
a) Blockages
b) Stones
c) Tumors
A kidney ultrasound creates images from sound waves that return from the kidney tissue. Many images are collected to
understand problems in the kidney.
If your doctor wants to see how blood flows to and from the kidney, Doppler imaging is used. This is an ultrasound method
that makes color images from the movement of flowing blood. It shows the flow of blood through the vessels. It provides
excellent motion information not available on a standard sonogram.
No need to be fast, prepare your bowel, or have a full bladder. The test is done as you lay on your back on the exam table. A
gel is spread on the skin to help transmit the sound waves. The kidneys are imaged by placing the transducer over both sides
of the upper belly.

8. Prostate Ultrasound ("transrectal ultrasound”) and Biopsy
The prostate is found at the base of the bladder in men. It circles the urethra like a napkin ring. The prostate makes part of the
ejaculatory fluid, which is needed for reproduction. If the prostate gets large, it may block the bladder.
The most common reason for a prostate ultrasound (also called "transrectal ultrasound") is to check men who might be at risk
for prostate cancer. Early cancer can’t easily be diagnosed by ultrasound alone. For this reason, a tissue sample ("biopsy") of
the prostate is also done.
To diagnose prostate disease, your doctor will want to examine your prostate gland and nearby tissue. Almost 70% of prostate
cancer malignancies are found in the outer zone of the prostate, by the rectum.
Prostate ultrasound can measure the volume or size of the prostate to help plan treatment. Patients receiving radioactive seed
implantation ("brachytherapy") to treat prostate cancer have transrectal ultrasound for this purpose. It is used to plan the
number of seeds needed and where to place them. This test may also be used to plan prostate surgery or other therapy (such
as thermal therapies). The study can measure prostate specific antigen density.
Before this test, you may be asked to use an enema. During the test, you will lie on your side or back on the exam table. The
ultrasound transducer probe is inserted into the rectum to see the prostate. The probe sends and receives sound waves
through the wall of the rectum and into the prostate gland. These sound waves create images for diagnosis. The urologist will
look for signs of prostate cancer. At the same time, a small tissue sample may be taken for a biopsy.
Local anesthesia may or may not be used with a biopsy. For a biopsy, a special needle is pushed through a channel on the
transducer. The biopsy is taken quickly. A number of biopsy "cores" are taken to be reviewed by a pathologist.
There are relatively no risks from this test. If you have a biopsy, you may feel limited discomfort.
It can take many days to get the biopsy results. If cancer is found, your urologist will talk about treatment options. If the biopsy
shows no cancer, your urologist will talk with you about plans for follow-up.

10. Scrotum/Testicular Ultrasound
A man’s testicles (testes) are in a skin-covered muscular sac called the scrotum. The testicles make sperm cells for
reproduction. They also make the male hormone, testosterone. The main reason for scrotal ultrasound is to check swelling or
pain. It’s also used to check masses in the scrotum or in the testes.
It is common for fluid to collect around the testis. This is called a hydrocele, and is not cancerous. Other things like cysts in the
epididymis ("spermatocele") or large veins in the scrotum ("varicocele") may be found. This study can also be used to look at
solid masses as a sign of testicular cancer.
Testicular ultrasound is used to evaluate almost all issues in the scrotum, the sac containing the testicles. It can detect
patterns from cancer, or if a mass is intra-testicular, extra-testicular, solid or cystic.
It is used for testicular torsion, and problems with blood flow in the testis. It can be used to prevent testicular death.
For this test, Color-Doppler imaging is used. This high-quality color imaging has made testicular ultrasound an accurate and
specific test.
This test needs no preparation. It is done as you lay on your back on the exam table. The scrotum is raised onto a towel and
warm gel is applied to help transmit sound waves. The transducer is moved over the area to create images.

12. The bladder is an organ made of smooth muscle. It stores urine until it’s released when you go to the bathroom. The
most common reason for bladder ultrasound is to check bladder draining. The urine that remains in the bladder after
urinating ("post void residual") is measured.
If urine remains, there can be a problem like:
a) Enlarged prostate
b) Urethral stricture (narrowing)
c) Bladder dysfunction
Bladder ultrasound can also give information about:
a) The bladder wall
b) Diverticula (pouches) of the bladder
c) Prostate size
d) Stones
e) Large tumors in the bladder
Bladder ultrasound doesn’t check the ovaries, uterus, or colon.
This test doesn’t require fasting or bowel preparation. If you are not checking for post void residuals, a full bladder is
needed. You may be asked to drink many glasses of water an hour before the exam.
The exam is done as you lay on your back on the exam table. A gel is spread on the skin to help transmit the sound
waves. The transducer is placed between your navel and pubic bone. The image is viewed on a monitor and read on the
spot. To check bladder draining, you’ll be asked to void. When you return, the bladder will be imaged again.

14. Modern methods of ultrasonography in urology
A significant landmark in the evolution of ultrasound technology has been a transition from the cumbersome static
B-mode imaging into real-time imaging systems with improved resolution.
The advancements that have had significant clinical implications include tissue harmonic imaging (THI), spatial
compound imaging, three-dimensional (3D) and four-dimensional ultrasound, contrast-enhanced ultrasound
(CEUS), elastography, endoscopic ultrasound, and fusion imaging.
THI provides a good demonstration of both cystic and solid lesions. Other advantages include improved near-field
resolution (closer to the transducer) and improved contrast resolution, i.e., the ability to perceive subtle changes
between adjacent tissues. One of the most useful applications of THI is characterization of cysts. THI is particularly
sensitive in recognition of pyonephrosis, increasing the conspicuity of fine internal echoes within the obstructed
collecting system.
Spatial Compound imaging allows an excellent definition of kidney profiles, detection of renal calculi, and more
accurate evaluation of parenchymal echotexture and calcifications. It is subjectively superior to conventional
ultrasound in evaluating patients with Peyronie's disease, as micro-calcifications are better detected.
3D sonography is considered as a promising alternative noninvasive technique for detection, localization, and
assessment of the perivesical spread of bladder tumors. The findings of tumors shown on 3D sonography agreed
well with conventional cystoscopy in terms of the location, size, and morphologic features. Thus, 3D-ultrasound
outperforms 2D-ultrasound in both diagnosis and therapeutic planning for urinary bladder carcinoma.

15. CEUS is useful for characterizing focal renal lesions. On CEUS, Renal Cell Carcinoma’s typically show heterogeneous
hypervascularity, with an early washout on the delayed phase. CEUS can assist in differentiating focal pyelonephritis from
mass lesions and aids in delineating abscesses, either parenchymal or perinephric, and also in the evaluation of vascular
malformations of the kidney. It can also be used in to monitor the development of renal abscesses in known cases of urinary
tract infection. Overall diagnostic accuracy of CEUS was significantly better than unenhanced sonography or CT in the
diagnosis of malignancy in complex cystic renal masses.
Ultrasound elastography is a noninvasive technique of imaging the stiffness or elasticity of the tissue by measuring the
deformation of the tissue to the small applied pressure.
Prostate elastography:
Endorectal real-time elastography enables the diagnosis of prostate cancer with a reported accuracy of 76%.
Transrectal ultrasound elastography :
It has multiple applications in the prostatic cancer, such as screening of prostate cancer, cancer detection and nodule
characterization, biopsy guidance on the suspicious nodule at TRUS elastography, grading and staging of prostate cancer,
therapy guidance, and monitoring therapeutic response by using serial elastographic measurements to detect interval
change.
Fusion or hybrid imaging means combining images from different imaging modalities. It is now being used as a real-time, 3D
visualization and navigation tool. The previously recorded CT, MRI, or positron emission tomography (PET)/CT dataset is
transferred to the ultrasound system and a coregistration from external or internal markers is performed either static or real
time. It improves diagnostic accuracy and guidance in prostatic biopsy procedures.

16. Conventional B-mode image (a) and THI (b) showing
better visualization of renal angiomyolipoma (arrow)
and renal cyst (star) in harmonic image
Images of conventional ultrasound (a) and compound
image (b) showing improved visualization of renal cyst
(short arrow) and clear demarcation of renal outline
(long arrow) in compound image

17. 3D-ultrasound image (a- axial, b- coronal and c- sagittal) of a
patient with hematuria showing bladder growth (short arrows)
in all the three axes in an image acquired in a single acquisition.
Foley's catheter bulb is seen in situ (long arrows)
Paired CEUS and corresponding conventional image
showing better visualization of complicated renal cyst
(long arrow) with enhancing septation (short arrow). It
was found to be papillary RCC at histopathology

18. Conventional ultrasound (a) color Doppler (b) and paired CEUS
with corresponding conventional image (c) show partially
exophytic solid renal lesion (arrows) with focal color flow and
homogeneous enhancement in postcontrast images (c). It was
found to be clear-cell RCC at histopathology
Paired TRUS elastography images (a- shear wave elastogram, top and
b- B-mode image, bottom) showing hypoechoic lesion in the right
posterolateral aspect of the prostate (arrow) (a) and a corresponding
elastogram color map showing high stiffness (124 kPa) and was
found to be prostate cancer on biopsy. Note the normal tissue on the
left side (b) with uniform low stiffness (28-37 kPa)

19. Fusion imaging of prostate: T2-weighted axial MRI image (a) and the
corresponding ultrasound image (b) showing a focal cystic area in
enlarged prostate (arrow) projecting into base of the urinary bladder
(star) and the corresponding overlay image (c) and 3D display (d)

20. Histo-Scanning :
It is an ultrasound-based software program for tissue
characterization. This 3D ultrasound imaging technology utilizes
the raw data usually obtained by the use of backscattered
ultrasound, to detect and visualize prostate cancer. Histo-
Scanning has shown encouraging results in the detection of
clinically significant prostate cancer.
Capacitative micromachined ultrasonic transducers:
These are transducers constructed of new materials
such as silicon wafers rather than piezoelectric
crystals. It is anticipated that this technology will
allow one single transducer head to generate multiple
frequencies and wavelengths, eliminating the need to
use several transducers during an examination.
Many forthcoming advances in ultrasound imaging under
evaluation are likely to be available for clinical applications in the
near future. Noteworthy among them are the following:

21. Ultrasonography is an integral part of the
diagnostic armamentarium in the practice of
modern urology. Ultrasound technology and its
applications for urologic disease continue to
evolve. These advances continue to play an
important role in the characterization of cystic
lesions, detecting contrast enhancement,
vascularity of focal lesions, and real-time
guidance of biopsies. The multidimensional
imaging techniques of ultrasound have now
made it possible to achieve improved
understanding of detailed spatial relationships,
which was previously possible only with
CT and MRI.