Some Imaging modalities in urology

1. Imaging in
Urology
Dr Shindang Pirfa

2. Outline
• Introduction
• Relevant Anatomy
• Ultrasonography
• Ionizing
• Urography
• Intravenous urography
• Cystography
• Micturating cystography
• Retrograde urethrography
• CT Scan
• MRI
• Nuclear imaging
• Conclusion.

3. Introduction
• Imaging continues to play indispensable role in diagnosis and management of urologic diseases
• like most other fields of medicine and science, it has seen substantial advancement and change
with the continuing growth of technology.
• The first 75 years of urological imaging were performed with plain-film radiography
• In the 1970s, 1980s, and 1990s saw the introduction and then widespread usage of sonography
(ultrasound), computed tomography (CT), magnetic resonance imaging (MRI), and radionuc1ide
imaging
• Urological imaging has benefited from these advances with a more precise ability to diagnose and
evaluate genitourinary disorders without surgical exploration.

4. Anatomy

5. • The hilum of the kidney lies medially, that of the left at L1 vertebral level and that
of the right slightly lower at L1/L2 level, owing to the bulk of the liver above.
• At the hilum, the pelvis lies posteriorly and the renal vein anteriorly with the
artery in between.
• There are usually seven pairs of minor calyces.
• Minor calyx pairs combine to form two or three major calyces, which in turn drain
via their infundibula to the pelvis.
• The pelvis may be intrarenal or partially or entirely extrarenal.

6. • The ureters
• Each is 20-25 cm long and is described as having a pelvis and
abdominal, pelvic and intravesical parts
• The ureter has a diameter of about 3 mm but is narrower at the
following three sites:
• The junction of the pelvis and ureter.
• The pelvic brim
• The intravesical ureter where it runs through the muscular bladder wall.

7. The Bladder
• This is a pyramidal muscular organ when
empty. It has a triangular-shaped base
posteriorly.
• In the male the neck is fused with the
prostate.
• Normal bladder wall is thickness is 2-
3mm in fully distended bladder
• First urge to void is felt at a bladder
volume of 150ml
• Bladder capacity is between 500-600 ml.
• The max capacity of bladder is up to
1200 ml. ( F > M).

8. The urethra
• In males
• It is 20cm long
• It has 4 parts
• The posterior urethra
• comprises the prostatic
• membranous urethra and
• the anterior part comprises
• the bulbous
• penile urethra.
• In females This is 3 - 4 cm long.

9. The Prostate
• prostate weighs 20 -25g and
• prostatic urethra which is about
2.5 cm in length.
• The prostate is perforated
posteriorly by the ejaculatory
ducts.
• Four zones: peripheral zone,
central zone (surrounds the
ejaculatory ducts), transitional
zone (surrounds the urethra),
and anterior fibromuscular zone

10. • The testicle
• The average testicle measures about
5 x 3 x 2.5 cm
• Weighs 10-15g
• It has a dense fascial covering called
the tunica albuginea
• separating it into about 250 lobules.
• The epidiymis
• It has an upper portion, the globus
major that is connected to the testis
by numerous efferent ducts from the
testis.
• its lower pole (globus minor), is
continuous with the vas deferens.

11. Ultrasonography
• An indispensable modality for evaluating the urogenital tract
• Ultrasound imaging is the result of the interaction of sound waves with
tissues within the human body.
• Images formed are produced by passing short bursts of alternating
electrical current through a piezoelectrical (material that expands and
contracts with current) crystal within a transducer which emits and
receives sound waves transmitted to the tissues.
• The frequencies commonly used in medical sonography are between 3.5
and 20 MHz.

12. Modes
• Gray-scale B-mode
• is the most commonly employed mode of ultrasound.
• This pulsed-wave technique produces real-time two-dimensional (2D) images
consisting of shades of gray.
• Evaluation of gray-scale imaging requires the ability to recognize normal patterns of
echogenicity from anatomic structures.
• Doppler mode
• Depends on the frequency shift when sound waves strike a moving object
• A color map may be applied to direction with the most common assignation of the
color blue to motion away from the transducer and red to motion toward the
transducer.
• 3D scanning

13. Contrast enhanced Ultrasound
• It involves the administration of intravenous contrast agents
containing microbubbles of perfluorocarbon or nitrogen gas.
• The addition of targeting ligands attached to the microbubble allows
the microbubble complex to selectively accumulate in diseased or
abnormal tissues.
• These microbubbles when affected by ultrasound increase vascular
contrast in a similar manner to intravenous contrast agents used in CT
and MRI

14. Appearance of prostate cancer at CEUS. (A) Baseline transrectal
US of the prostate shows no focal abnormalities in the peripheral
portion of the gland. (B) Twenty-eight seconds after microbubble
injection a hypervascular area is recognized in the right prostate
lobe (arrowheads).

16. Renal Ultrasound
Technique:
• The transducer normally used for renal ultrasonography is a curved array transducer of 3.5 to 5.0
MHz.
• Transducers of a higher frequency may be used for pediatric patients.
• Scanning of the right kidney is performed with the patient supine. The kidney is located by
beginning in the midclavicular line in the right upper quadrant. In the sagittal plane the
transducer is moved laterally until the midsagittal plane of the kidney is imaged.
• The left kidney is slightly more cephalad than the right kidney.
• Bowel gas is more problematic on the left because of the position of the splenic flexure of the
colon.
• Ultrasound imaging of the left kidney lacks the liver as an acoustic window, and it is sometimes
more difficult to image the left kidney in a true sagittal plane.

17. Indications
• Assessment of renal and
perirenal masses
• Assessment of the dilated upper
urinary tract
• Assessment of flank pain
• Evaluation for and monitoring of
urolithiasis
• Guidance for transcutaneous
renal biopsies, cyst aspiration, or
ablation of renal masses
• Intraoperative renal parenchyma
and vascular imaging for
ablation of renal masses
• Percutaneous access to the renal
collecting system
• Postoperative evaluation of
patients after renal and ureteral
surgery.
• Postoperative evaluation of renal
transplant patients

18. Ultrasound from obstructed megaureter demonstrating
dilated collecting system and proximal ureter.
Normal right kidney

19. Transabdominal Pelvic Ultrasound
• It is a noninvasive method for evaluating the lower urinary tract and
prostate in men and the bladder in women.
• A curved array transducer of 3.5 to 5 MHz is most commonly
employed
• In pediatric patients, a higher-frequency transducer may be used.

20. Indications
• Measurement of bladder volume
or postvoid residual urine
• Evaluation of bladder wall
configuration and thickness
• Evaluation of hematuria of lower
urinary tract origin
• Detection of ureteroceles
• Assessment for ureteral
obstruction
• Detection of peri-vesical fluid
collections
• Evaluation of clot retention in
bladder
• Confirmation of urethral
catheter position in bladder
• Guidance of suprapubic tube
placement
• Assessment of prostate size and
morphology

21. Prostate volume measurement.
Transabdominal ultrasound images of prostate in sagittal
(left image)
and transverse planes (right image)
Postvoid residual urine volume measurement.
Ultrasound images of bladder in sagittal
and transverse planes showing elevated residual urine
and prostate enlargement

22. Transrectal Ultrasonography of the Prostate
• It is minimally invasive and provides exquisite anatomic detail of the
prostate and periprostatic tissues.
• It has become an extension of the urologist’s finger in the detection of an
enlarged prostate
• A high-frequency 7.5-10MHz transducer is usually used.
• Indications:
• Abnormal digital rectal exam
• Prostatic assessment with sonographic-controlled biopsy
• Evaluation for and aspiration of prostate abscess
• Pelvic pain
• Prostatitis/prostadynia
• Hematospermia

23. The prostate in a 35-year-old male (top panel)
and 65-year-old male (bottom panel).
Note the prominence of the transition zone
in the older male
The adult prostate. The top panel represents a transverse view
and the bottom a longitudinal view.
The transition zones (TZ), peripheral zones (PZ),
anterior fibromuscular stroma (FS),
seminal vesicle, and urethra (U) are indicated.
Notice the symmetric echogenicity of the left and right sides in
the top panel

24. Ultrasound- The testis and scrotum
• A high-frequency transducer (10–15 MHz) used for excellent spatial
resolution.
• Sonography is highly accurate in differentiating intratesticular from
extra-testicular disease, and in the detection of intratesticular
pathology.
• Ultrasound is commonly used to evaluate acute conditions of the
scrotum. It can distinguish between inflammatory processes, inguinal
hernias and acute testicular torsion

25. Indications
• Assessment of scrotal and testicular mass
• Assessment of scrotal and testicular pain
• Evaluation of scrotal trauma
• Evaluation of infertility
• Follow-up after scrotal surgery
• Evaluation of the empty or abnormal scrotum

26. Ultrasonography
Gray scale ultrasound showing a left hydrocele (H)
Chronic epididymitis :
Gray scale ultrasound showing
increase of echogenicity and microcalcifications seen
in the caput epididymis (arrows)

27. Ultrasonography
• Advantages
• Ease of use
• High patient tolerance
• Noninvasiveness
• Lack of use of ionizing radiation
• Relative low cost
• Wide availability.
• Bedside sonography and guided
procedures can be performed.
• Limitations
• Dependence on the operator’s
skill
• limited field of view
• patient’s habitus.
• a relatively low signal-to-noise
level
• tissue non-specificity,

28. Radiography
• Radiography is possible because tissues differ in their ability to absorb
and reflect x-rays(ionized radiation) produced from a source
• The reflected x-rays emerge from the patient with varying amounts of
energy attenuation and strike an image recorder such as a film
cassette or the input phosphor of an image-intensifier tube, thus
producing an image.

29. • The patient is exposed to radiation .
• Absorbed dose is the energy absorbed from the radiation exposure
and is measured in units called gray (Gy).
• A conversion factor for the absorbed dose yields the equivalent dose
measured in sieverts (Sv).
• Based on the linear no-threshold model used in radiation protection
there is no safe dose of radiation.
• An effective radiation dose of as little as 10 mSv may result in the
development of a malignancy in 1 of 1000 individuals exposed

30. Radiation Exposure From Common
Urologic Imaging Procedures

31. Radiography
• Conventional radiography has largely been replaced by CT
• It however remains useful for preoperative diagnosis and
postoperative evaluation in a variety of different urologic conditions.
• Conventional radiography includes
• Plain abdominal radiography.
• Intravenous urography
• Antegrade pyelography
• Retrograde pyelography
• Retrograde urethrography
• Cystography.

32. Contrast media
• A substance that renders an organ structure more visible than is
possible without its addition

33. • Water-soluble contrast media
• Water-soluble iodinated contrast media can be classified by osmolality.
1. High osmolar contrast media
• It is approximately five to eight times the osmolality of serum.
• HOCM were associated with high rates of adverse events
• HOCM remain used for gastrointestinal and cystourethral
administration, including the following agents:
• Diatrizoate sodium/meglumine (Gastrografin, MD-Gastroview,
Cystografin)
• Iothalamate sodium/meglumine (Conray, Cysto-Conray)

34. 2. Low osmolar contrast media
• It is less than three times the osmolality of human serum and preferred for
intravascular and intrathecal administration.
• Low osmolar contrast media are nonionic monomers composed of tri-iodinated
benzene rings with various side chains that contain polar alcohol (-OH) groups that
make them water-soluble but does not dissociate.
• LOCM in current use include the following:
• iohexol (Omnipaque), iopromide (Ultravist),ioversol (Optiray)
3. Iso-osmolar contrast media
• It is the most recent class of agents that consist of a molecule with two benzene
ring.
• It doesn not dissociate in water
• Toxicity of contrast agents decreases
• Example: Visipaque

35. Adverse Reactions to Intravascular Contrast Media
1. Allergy like reactions manifest in a similar manner to allergic
reactions and differ immunologically from true ARs. Given that an
antigen-antibody response is rarely identified.
• mechanisms in ALRs:
• release of vasoactive substances including histamine
• activation of physiologic cascades, including complement, kinin, coagulation,
and fibrinolytic systems
• inhibition of enzymes including cholinesterase, which may cause prolonged
vagal stimulation
• the patient’s own anxiety and fear of the actual procedure.
• ALRs are not dose dependent.

36. Delayed Contrast Reactions
• This can occur from 3 hours to 7 days after the administration of
contrast.
• Seen in 14-30% of patients after the injection of ionic monomers and
in 8-10% of patients after the injection of nonionic monomers.
• Common reactions include:
• Cutaneous exanthem
• Pruritis without urticaria.
• Nausea, vomiting, drowsiness, headache, and flulike symptoms also may
occur.
• They are self limiting.

37. Risk factors for development of contrast
allergy
• Allergy
• Anxiety
• asthma
• Beta-blocker
• Cardiac abnormality
• Hyperthyroidism
• Myesthenia gravis

38. Plain film(KUB)
• The plain abdominal radiograph is a conventional radiography study,
which is intended to display the Kidney Ureter Bladder.
• It could be employed as a primary study or as a scout film (in
anticipation of contrast media).
• Secondary findings on plain radiography such as rib fractures, pelvic
fractures may indicate serious associated urologic injuries.

39. KUB film showed multiple calcifications at the
right renal pelvic and distal ureteric regions.
The kidney, ureter and bladder (KUB) X-ray shows
a retained stent with stone in the ureter
and kidney. The arrow indicates ureteral stones.
The arrowhead indicates renal stones.

40. Indication
• Preliminary film in anticipation of contrast administration
• Assessment of the presence of residual contrast from a previous
imaging procedure
• Pre- and post-treatment assessment of renal calculus disease
• Assessment of the position of drains and stents
• Adjunct to the investigation of blunt or penetrating trauma to the
urinary tract

41. Limitations
• overlying stool and bowel gas may obscure small calculi.
• Stones may be obscured by other structures (such as bones or ribs)
and stones that are poorly calcified or composed of uric acid may be
radiolucent.
• Calcifications in pelvic veins or vascular structures may be confused
with ureteral calculi
• Plain radiography has a very limited role in evaluating soft tissue
abnormalities of the urinary tract.

42. UROGRAPHY
• Involves instillation of contrast material to better visualize the
collecting luminal structures of the kidneys, ureters, bladder, urethra.
• This can be done after IV injection or direct instillation into the
urinary tract.
• Intravenous Urography
• Cystography
• Voiding cystourethrography
• Retrograde urethrography

43. One-shot trauma IVU
• Patients with penetrating renal and hemodynamically unstable blunt renal trauma
patients who require immediate surgical exploration can undergo one-shot, high-
dose intravenous urography (IVU) prior to any renal exploration.
• Intravenous administration of contrast followed by a single abdominal radiograph
10 minutes later,
• No scout film is necessary.
• Abnormal or equivocal IVU findings warrant further exploration or radiographic
staging. For the hemodynamically stable patient, further and more accurate staging
can be achieved with CT scanning.
• For unstable patients with abnormal IVU findings, surgical exploration is warranted.

44. Intravenous urography
• It is a specialized radiological investigation which employs the use of
contrast medium to outline the Kidneys, Ureters and the Urinary
bladder.
• It is both a functional and anatomical test on the excreting system. is a
true functional test because CM molecules are rapidly removed
from the blood stream & are excreted completely by a normal
kidney

45. Indications
• Ureteric fistulas and strictures
• Complex UTI(including tuberculosis).
• persistent or frank hematuria
• tumors
• Potential renal donors
• Differentiation of function of both kidneys
• Renal/ ureteric calculi(Nephrolithiasis)
• Obstructive uropathy
• Hydronephrosis
• congenital anomalies
• Neurological disorders affecting urinary tract
• Enuresis(involuntary urination) and H/o recurrent UTI
• Adults
Children

46. contraindication
• High serum creatinine.
• Pregnancy.
• Allergy to contrast.
• Hepatorenal syndrome.
• Thyrotoxicosis

47. Film
• Immediate film (Nephrogram phase)
• 5-15 min film (secretory phase)
• 30min film (ureterogram phase)
• 45min film (cystogram phase)
• Post voiding film

48. 5-15 minutes film (Secretory
phase) 30min film (ureterogram phase)
45 min film Cystography phase Post micturation

49. • Advantages
• Rapid overview of the entire
urinary tract
• Demonstrates anatomy of the
collecting system
• demonstrates calcifications
• it is sensitive for obstruction
• low cost
• Limitations
• it depends on kidney function
• It cannot demonstrate cystic or
solid masses
• the perinephric space is not
demonstrated
• may miss small stones
• Inconvenience of a long filming
period

50. Right Renal agenesis Right duplicating ureters

51. Complications
• Due to CM:
Reactions due to CM: mild, moderate and severe.
• Due to technique:
• Incorrectly applied abdominal compression may produce intolerable
discomfort or hypotension.
• Swelling ,pain and infection during injection
• Extravasation of CM

52. Cystography
• It is employed primarily to evaluate the structural integrity of the
bladder.
• Filling defects such as tumors and stones may be appreciated.
• Contrast is usually instilled via a transurethral catheter, but when
necessary can be administered via percutaneous suprapubic bladder
puncture.

53. Indications
1. Evaluation of intravesical pathology
2. Evaluation of bladder diverticula
3. Evaluation of inguinal hernia involving the bladder
4. Evaluation of colovesical or vesicovaginal fistulae
5. Evaluation of bladder or anastomotic integrity after surgical
procedure
6. Evaluation of blunt or penetrating trauma to the bladder

54. Technique
• Patient is positioned supine
• A scout plain abdominal x-ray done
• 300-400 ml of dilute contrast is instilled into the bladder via the
urethral (if urethral injury excluded) or the suprapubic route.
• The initial film is taken after 100 ml contrast is instilled to check gross
extravasation.
• Films are then taken after the entire contrast is instilled.
• A post-drainage film excludes extravasation hidden by a distended
bladder.

55. The patient has undergone radical retropubic prostatectomy. (A) During bladder filling, contrast
is seen adjacent to the vesicoureteral anastomoses (arrow). (B) The post-drain film clearly demonstrates
a collection of extravasated contrast (arrow).

56. Retrograde Pyelography
• Retrograde pyelograms are performed to opacify the ureters and
intrarenal collecting system by the retrograde injection of contrast
media.
• Any contrast media that can be used for excretory urography is also
acceptable for retrograde pyelography.
• Retrograde pyelography has the unique ability to document the
normalcy of the ureter distal to the level of obstruction and to better
define the extent of the ureteral abnormality.

57. Indications
• Evaluation of congenital and acquired ureteral obstruction
• Elucidation of filling defects and deformities of the ureters or
intrarenal collecting systems
• Evaluation of hematuria
• Surveillance of transitional cell carcinoma
• In the evaluation of traumatic or iatrogenic injury to the ureter or
collecting system

58. This scan shows stricture (arrow) of the left ureteropelvic junction and hydronephrosis.

59. Limitations
• Difficult in: cystitis
• Bladder tumors
• Bleeding abnormalities
• Bladder outlet obstruction
• Trauma to the ureteral orifice
complications
• Trauma to the ureters
• Urinary Tract Infection with the risk of
sepsis
• Adverse reactions to contrast.

60. Loopography
• It is performed in patients who have undergone urinary diversion.
• Historically the term “loopogram” has been associated with ileal conduit
diversion but may be used in reference to any bowel segment serving as a urinary
conduit.
• Procedure
• It is a retrograde study in which contrast is injected via the abdominal wall stoma
of ileal conduit.
• A series of images are taken in a number of positions to assess the conduit.
• It is typical to observe contrast entering the ureters during the procedure.

61. • Limitations
• Evaluation of infection, hematuria,
renal insufficiency, or pain after
urinary diversion
• Surveillance of upper urinary tract
for obstruction
• Surveillance of upper urinary tract
for urothelial neoplasia
• Evaluation of the integrity of the
intestinal segment or reservoir
after the primary anastomosis, follow-up distal loopography
shows continuity of the distal colon.

62. MICTURATING CYSTOURETHROGRAM
• It is a study of the lower urinary tract in which contrast is introduced
into the bladder via a catheter.
• The purpose of the examination is to assess the bladder, the urethra,
postoperative anatomy and micturition in order to determine the
presence or absence of bladder and urethral abnormalities,

63. Technique
The study may be performed with the patient supine or in a semi-
upright position
• A preliminary pelvic plain radiograph is obtained.
• In children, a 5- to 8-Fr feeding tube is used to fill the bladder to the
appropriate volume.
• In the adult population a standard catheter may be placed and the
bladder filled to 200 to 400ml.
• The catheter is removed and a film is obtained.
• During voiding, AP and oblique films are obtained.
• Postvoiding films should be performed

64. • Indications
• Bladder outlet obstruction
• dysfunctional voiding
• hematuria
• trauma
• urinary incontinence
• neurogenic dysfunction of the
bladder, e.g. spinal dysraphism
• congenital anomalies of the
genitourinary tract
• postoperative evaluation of the
urinary tract
Contraindications
• Acute urinary tract infection
• Hypersensitivity to contrast
medium
• Pregnancy

65. • Catheter trauma- may produce dysuria, frequency haematuria and
• urinary retention
• Complications of bladder filling e.g, perforation from over distension
prevented by using a non-retaining catheter, e.g. Jaques
• Catheterization of vagina or an etopic urethral orifice

66. • COMPLICATIONS
• DUE TO CONTRAST MEDIUM
- Adverse reactions may result from absorption of
contrast medium by the bladder mucosa
- Contrast medium – induced Cystitis
• DUE TO TECHNIQUE
• Acute UTI
• Catheter trauma – may produce Dysuria,
Frequency, Haematuria & Urinary retention
• Perforation from overdistension, wrong
catheterization
• Retention of Foley’s catheter
• Limitations
• This study requires bladder filling
using a catheter.
• Filling of the bladder may stimulate
bladder spasms at low volumes, and
some patients are unable to hold
adequate volumes for investigation.

67. Retrograde urethrogram
• It is a study meant to evaluate the anterior and posterior urethra.
• It demonstrates the total length of a urethral stricture
• It also shows the anatomy of the urethra distal to the stricture
• Indications
• Evaluation of urethral stricture disease
• Location of stricture
• Length of stricture
• Assessment for foreign bodies
• Evaluation of penile or urethral penetrating trauma
• Evaluation of traumatic gross hematuria

68. TECHNIQUE
• This study is done with Patient supine on the examining
couch
• Using strict ASEPSIS, a penile clamp is applied, the tip of
the Foley's catheter is inserted into the FOSSA
NAVICULARIS & its balloon inflated at this site with 1-
2ml of N/saline
Prewarmed contrast media (This helps reduce spasms of
the urethra) is injected under fluoroscopic control & films
are taken

69. • COMPLICATIONS
a) DUE TO CM
- Adverse reactions are rare
b) DUE TO THE TECHNIQUE
- Acute UTI
- Urethral trauma
- Intravasation of CM, especially if excessive
pressure is used to overcome a stricture

71. Pericatheter RUG
• Pericatheter urethrograms can be done to assess urethral patency
while a Foley catheter is in place.
• It is often used after urethroplasty to decide whether or not a Foley
catheter should be removed.
• Contrast was then given through a paediatric feeding tube placed in
the penile urethra next to the Foley catheter (pericatheter).
• The contrast administered outlines the anterior and posterior urethra
around the Foley catheter. No leak of contrast.

73. Antegrade ureterography
• Outlining the renal collecting structures and ureters by percutaneous
catheter is occasionally done when
• excretory or retrograde urography has failed
• When RUG contraindicated.
• when there is a nephrostomy tube in place and delineation of the collecting
system is desired.
• contraindications
• Uncontrolled bleeding diathesis.

74. • Patient preparation
• Prophylactic antiobiotics
• Fasting for 4 hr for Antegrade
urography
• Identifying collecting system
• Site of puncture
• LA
• Puncture & catheter
• Oblique and AP images are taken
with gentle introduction of water-
soluble contrast medium.
• Aftercare
• Dressing site of needle
• insertion.
• Monitoring Vital signs every 30min
for 6 hours.
• Pain management if needed.

75. Antegrade pyelography shows the right pyeloduodenal fistula:
(A, B) Leakage of contrast media to the duodenum from the right renal pelvis
before endoscopic ligation on pyelography during nephrostomy.
(C) No evidence of contrast leakage to the duodenum 1 week after successful endoscopic clipping and snaring.

76. COMPUTED TOMOGRAPHY SCAN (CT Scan)
• In CT scanning, a thin, collimated beam of x-rays is passed through
the patient and captured by an array of solid-state or gas detectors.
• The interconnected x-ray source and detector system are rapidly
rotated in the gantry around the recumbent patient.
• Computers integrate the collected x-ray transmission data to
reconstruct a cross-sectional image (tomogram).

77. COMPUTED TOMOGRAPHY SCAN (CT Scan)
• 1. Spiral (or helical) CT uses a slip-ring gantry that rotates
continuously while the patient moves constantly through the
collimated x-ray beam.
• 2. CT angiography, multidetector CT angiography may also have a role
in prostate cancer localization.
• 3. CT urography

78. COMPUTED TOMOGRAPHY SCAN (CT Scan)
• CT urography is a CT examination of the entire urinary tract before
and after the administration of IV contrast material and includes
excretory phase images.
• It gives both anatomical and functional information.

79. Indications
• Hematuria
• Suspected urothelial cancer (e.g., positive urine cytology)
• Follow-up urothelial cancer
• Hydronephrosis ?etiology
• Congenital anomalies
• trauma with suspected ureteral injury
• Recurrent and/or complex urinary infections to exclude an underlying obstructive etiology or
formation of an abscess.
• CT urography is also used to detect renal stones
• may be used in the preoperative planning of percutaneous nephrolithotomy (PCNL).
• CT urography has also been used in the postoperative setting to evaluate the urinary collecting
system following

80. CTU Protocol
• Unenhanced phase
• Nephrographic phase after 90-100 secs
• Pyelographic phase after 12-15 minutes
• 4 Phase protocol (5 min and 7.5 min)
• Contrast media
• Omnipaque (100-150 ml non ionic contrast media at a rate of 2-4
ml/second)

81. • Renal Tumors
• Enhancement : Nephrographic
phase
• Location : Renal cell carcinoma is
frequently located at the
periphery or
• near the cortico-medullary
junction of the kidney as it
originates in the renal cortex

82. MALIGNANT LOWER POLAR LEFT RENAL MASS WITH
ENHANCING MALIGNANT THROMBUS WITHIN THE IVC
AND SECONDARY VARICOSITIES OF THE LEFT TESTICULAR VEIN

83. DISPLACED LEFT KIDNEY WITH
DOUPLEX RIGHT COLLECTING SYSTEM

84. Advantages of CT
• A wide field of view
• The ability to detect subtle differences in the x-ray attenuation
properties of various tissues
• good spatial resolution, anatomical cross-sectional images,
• relative operator independence.

85. Limitations of CT
• restriction to the transaxial plane for direct imaging,
• tissue nonspecificity,
• low soft-tissue contrast resolution, and the need for contrast media
(both oral and intravenous).
• Even with careful use of contrast media, tissue contrast is sometimes
unsatisfactory.
• Finally, radiation exposure is a consideration with multisequence
• CT imaging

86. • Advantages of IVU over CT urography
• Better spatial resolution
• Lesser radiation dose
• Cheaper

87. Magnetic Resonant Imaging
• It is used to provide a comprehensive assessment of The urinary
collecting system, renal parenchyma and surrounding structures.
• MRI is used primarily to stage tumors
• to differentiate between benign bladder wall hypertrophy and
infiltrating malignant neoplasm.
• MRI is applicable to the evaluation of undescended testis, trauma,
epididymo-orchitis, and tumors.

88. Magnetic Resonance Imaging Contrast Agents
MRI studies are being performed with contrast media.
• Extracellular MRI contrast agents contain paramagnetic metal ions,
such as Copper, manganese, and gadolinium were the potential
paramagnetic ions for use with MRI.
• Gadolinium, however, is the most powerful, having seven unpaired
electrons
• positive enhancers
• reducing the T1 and T2 relaxation times
• increasing tissue signal intensity on T1-weighted images, while having little
effect on T2-weighted images.

89. Magnetic Resonance Imaging Contrast Agents
• incidence of Acute adverse reactions is 0.07% to 2.4%.
• Include: nausea, emesis, headache, paresthesias, dizziness, and itching.
• Reactions resembling an ALR occur in 0.004% to 0.7% of cases.
• Reactions consisting of rash, hives, or urticaria are most frequent; the patient rarely develops
bronchospasm.
• The severe, life-threatening anaphylactoid or nonallergic anaphylactic reactions are exceedingly rare
(0.0001% to 0.001%).
• Gadolinium agents are considered to have no nephrotoxicity at approved doses for MRI.
• However, because of the risk of nephrogenic systemic fibrosis (NSF) in patients with severe renal
dysfunction.

90. Nephrogenic Systemic Fibrosis
• NSF is a fibrosing disease of the skin, subcutaneous tissues, lungs, esophagus, heart, and skeletal muscles.
• Onset of NSF varies between 2 days and 3 months after exposure to gadolinium with rare cases appearing
years after exposure
• Initial symptoms typically include: skin thickening and/or pruritus. subacute swelling of distal extremities
with some affected patients developing contractures and joint immobility within days of exposure. Death
may result in some patients,
• Patients at risk:
• Severe or end-stage CKD (eGFR <30 mL/min/1.73 m2) without dialysis
• AKI
• Solitary kidney
• Known kidney cancer
• Hypertension requiring medical therapy
• Diabetes mellitus
• The exact mechanism causing NSF is not known.

91. Indications for MRI
• Urolithiasis
• Urinary Tract Obstruction unrelated to Urolithiasis
• Hematuria
• Congenital Anomalies
• Pre- and Postoperative Assessment in renal transplant patients.
• Absolute contraindications to MRI include
• The presence of metals such as intracranial aneurysm clips, intra-orbital metal
fragments
• Any electrically, magnetically, or mechanically activated implants (including
cardiac pacemakers, bio-stimulators, neurostimulators, cochlear implants, and
hearing aids).

92. limitations and challenges
• Relative insensitivity for renal calculi
• Relatively long imaging times
• Sensitivity to motion
• Cost / Expensive

93. MR Urographic Techniques
• The most common MR urographic techniques used to display
the urinary tract can be divided into two categories:
• (a) Static-fluid MR urography (also known as static MR
urography, T2-weighted MR urography, or MR hydrography)
• (b) Excretory MR urography (also known as T1-weighted MR
urography)

94. Static-Fluid MR Urography
• T2-weighted techniques were the first clinically relevant means of
visualizing the urinary tract with MR imaging .
• Static-fluid MR urography treats the urinary tract as a static column
of fluid, using one of a variety of T2-weighted sequences that exploit
the long T2 relaxation time of urine .

95. Static-Fluid MR Urography
• Static-fluid MR urography
depends on the presence of
urine within the collecting
systems rather than the
excretory function of the
kidneys.
• It is ideally suited for patients
with dilated, obstructed
collecting systems

96. Static-Fluid MR Urography
• However, identifying the cause of obstruction often requires
additional sequences.
• Static-fluid MR urography does not require the excretion of contrast
material and is therefore useful for demonstrating the collecting
system of an obstructed, poorly excreting kidney .

97. Static-Fluid MR Urography
• For patients with nondilated systems, the use of hydration, diuretics,
or compression may enhance the quality of MR urography .
• Normal and abnormal fluid-filled structures can interfere with
static-fluid MR urography, since the T2-weighted techniques used to
display the urinary tract are not specific for urine.
• For this reason, intravenous hydration may be preferable to oral
hydration prior to static-fluid MR urography in patients with
nondistended ureters.

98. Excretory MR Urography
• Excretory MR urography is roughly analogous to CT urography and
conventional intravenous urography (IVU).
• A gadolinium-based contrast agent is administered intravenously,
and the collecting systems are imaged during the excretory phase.
• Gadolinium shortens the T1 relaxation time of the urine, allowing the
urine to initially appear bright on T1-weighted images.
• At standard doses of 0.1 mmol/kg, gadolinium-based contrast
material quickly becomes concentrated in the urine, and sufficiently
concentrated contrast material reduces the signal intensity of the
urine due to T2* effects .

99. • Advantages of MRI include
1. direct imaging in any plane desired (though transverse, sagittal, and
coronal are most standard)
2. Excellent soft-tissue contrast
3. Imaging without exposure to ionizing radiation
4. less operator dependence.
5. MRI can image blood vessels and the urinary tract without contrast
material.

100. Nuclear scintigraphy
• has been used in clinical nephro-urology since the early 1960s.
• It provides functional and anatomic information.
• Radiolabelled agent is given intravenously image obtained using a
gamma camera
• Functional information is quite unique. For example, a radionuclide
study can separately measure renal function on each side.

101. Agents used
• Glomerular Agents
• The two agents commonly used within this category are iodine-125 (125I)-iothalamate and
technetium-99m (99mTc)-diethylenetriamine pentaacetic acid (DTPA).
• 99mTc-DTPA is commonly used to measure GFR.
• Tubular Agents
• Radioiodinated orthoiodohippurate (OIH, hippuran) and 99mTc-mercaptylacetyltriglycine (99mTc-
MAG3) are cleared from the kidneys mainly by tubular secretion.
• 99mTc-MAG3 provides superior renal functional images with reasonable anatomic evaluation.
• 99mTc-MAG3 is used to measure effective renal plasma flow (ERPF) and assess renal perfusion and
function. and to asses for functional obstruction.
• Cortical Agents
• There are two renal cortical agents available: 99mTc-dimercaptosuccinic acid (DMSA) and 99mTc-
glucoheptonate (GH).
• Allows detection of cortical abnormalities

102. Isotope renogram showing reduced secretion on
right side.

103. Indications
• Assessment of renal perfusion
• Assessment of renal function
• Pyelonephritis
• Urinary tract obstruction
• Renal transplantation
• Acute renal failure.
• Also detecting vesicoureteral reflux (VUR)
• Torsion epididymoorchitis.
• Congenital anomalies

104. Limitations
1. Poor resolution images.
2. Nuclear renal images cannot reliably differentiate between cysts and
tumors.
3. Medications can affect effective renal blood flow and confound
results.
4. lengthy study (40min-60min)

105. Conclusion
• The ever changing uroradiology remains indispensable in the diagnosis and treatment of patients
with urologic disorders.
• The pace of innovation in diagnostic radiology has increased exponentially, in tandem with
computer advances
• Imaging of the urinary tract, as a result, has become more flexible and precise, with new
procedures offering a great selection of options and the implementation of new imaging
algorithms.
• Ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) provide
higher soft-tissue contrast resolution than conventional radiography, as well as multiplanar
imaging capability, resulting in significant advances in almost all areas of uroradiology.

106. References
• Campbell -Walsh urology 11th edition
• Smith & Tanagho's General Urology, 17ed Jack W. McAninch et al
• Hinman’s Atlas of Urosurgical anatomy 2nd edition
• Diagnostic Radiology Genitourinary Imaging 3rd ed.
• Google Internet images .