1. DR. ANIL RAWAT
ASSISTANT PROFESSOR
Conventional techniques in urinary system imaging
(IVP, MCU, RGU)
2. History
In 1896, for first time, X-ray demonstration of renal calculi
in a patient was done.
Techniques of cystography, retrograde pyelography and
retrograde urethrography were described within 15 years
after that.
With introduction of RGP, renal PCS and ureters were made
available for X-ray study.
In 1929, Moses Swick invented uroselectan (5-iodo-2-
pyridone-N-acetic acid ) which led to revolutionary advent
of IVP.
3. Progressive improvement in the chemistry of contrast media
made IVP an excellent method for studying PCS and renal
parenchyma.
Subsequent development of better and safe contrast media like
iohexol, iopamidol etc. brought a current era of lower osmolality
radio-opaque contrast media.
Currently, the use of USG, CT, MRI and radionuclide scanning
has superseded older conventional techniques at many fronts in
the form of high sensitivity, specificity and better safety margins.
4. EXCRETORY UROGRAPHY
Excretory urography refers to visualization of the kidney
parenchyma, calyces and pelvis after iv. Injection of
contrast.
The excretory Urogram is the classic routine investigation
of Uroradiology.
Technically satisfactory IVU demonstrates clearly and
completely both the renal parenchyma & the collecting
system including the calyces, renal pelvis, ureters and the
urinary bladder and gives an indication of their function.
5. INDICATIONS:
Hematuria
Renal colic
Renal trauma
Persistent pyuria
Prior to percutaneous urological procedures to define renal
anatomy
Prior to surgery involving risk of significant ureteric injury
After surgery e.g. Ureteric surgery
Ureteric strictures or fistulas
Complex urinary tract infection (including tuberculosis)
Work up of live donor in renal transplant
To screen for renal anomalies in patient with multiple
congenital anomalies.
6. CONTRAINDICATIONS:
No absolute contraindication
Relative contraindications
• Previous reaction to contrast media
• Asthma
• Renal & hepatic failure
• Multiple myeloma
• Pregnancy
• H/o allergy to other drugs
• Thyroid disease
• Diabetes
• Sickle cell disease
7. PATIENT PREPARATION
Dehydration : Overhydration should be avoided but dehydration
is unecessary. It is a potentiating factor for contrast induced
nephrotoxicity.
Bowel preparation
2 tab charcol or gasex TDS X 2days prior to examination &
25 ml Castor oil or 2 tab Dulcolax at night X 2 days prior
Ambulatory for 2 hrs prior to examination to reduce bowel gas
A group of children in which we never perform bowel
preparation are those with myelomeningocele.
• Fasting on the morning of the study
8. EXPOSURE FACTORS
Kvp 65-75
mA Sufficiently high to allow short exposure
times(mA-600-1000 mA or 60 MAS),
Exposure time < 0.1 sec (approx 80 msec in adults, < 50
msec in children)
Film/Screen combination Medium speed
All exposures are to be made in suspended expiration to
minimize geometric distortion of renal image because deep
inspiration causes descent and ventral rotation of lower poles
of the kidneys
9. History taking
Clinical history of patient
Co-morbid illnesses eg. diabetes, hypertension,
cardiac disease, thyroid disease and other risk
factors
Renal function (S. creatinine)
LMP in females
Drugs
Written informed consent before contrast
administration
10. Technique
KUB radiograph, an indispensable part of sequence.
Appropriate technique (65–75 kVp, high mA, short
exposure time) to maximize inherent soft-tissue contrast
and optimize visualization of calcium-containing lesions
that are potentially of urinary tract origin.
Proper KUB may require additional images for evaluating
portions of urinary tract not seen on standard 14* 17-inch
image (area from suprarenal region to a level below
symphysis pubis).
Patient should void immediately prior to examination.
11. PROCEDURE
Plain film of the abdomen (Scout film)
Area to be included from the suprarenal region to
the level below the symphysis pubis.
The patient should void immediately prior to undergoing this
examination.
Center the rays at the level of the iliac crest in the midsagittal
plane.
Gonadal shields should be used routinely throughout the
examination.
12.
13.
14.
15. Things to look for in plain abdominal radiograph:
1. Calculus/ calcifications: Assessment of probable location
of calcifications in abdomen with respect to urinary tract
should be made prior to contrast injection, which can
obscure a calcification. Oblique radiographs helpful.
2. Skeletal abnormalities: spinal deformity, metabolic bone
changes, skeletal metastasis.
3.Intestinal gas pattern: Ileus, obstruction.
4.Abdominal masses: May be seen better on scout view.
5.Foreign bodies: Opaque foreign bodies or barium.
19. Indications for LOCM
Those at high risk of anaphylactoid reaction:
Previous reactors
Asthamatics
Atopics
allergy to other drugs
20. Those unable to tolerate a high osmotic load
Poor cardiac reserve
Infants and elderly patients
Sickle cell disease or trait
Pre-existing renal impairment
21. Contrast administration
Bolus infusion of 350-370 strength water-soluble
contrast is done with 18 gauge needle into
antecubital vein.
adult dose 50 ml
elderly and
obese patient
75 ml
small children 1.5 ml/kg
neonate 4ml/kg
22. Although modern contrast medium is exceptionally safe,
there is a small risk of serious reactions.
Most dangerous of these are anaphylactoid -type
hypersensitivity reactions. To minimise the risks of these a
routine inquiry about previous contrast exposure and
allergy is recommended.
Injection should be through some form of indwelling
cannula or needle that can he taped into place for duration
of investigation.
Most adverse events are likely to take place within first few
minutes after injection. Emergency drugs, oxygen and
resuscitation equipment should also be readily available.
23. Filming sequence
1 min –nephrogram (often omitted as renal outline are
adequately visualised on 5 min radiograph)
5 min- collecting system
Abdominal compression at 5 min
10 min - proximal ureters
15 min ‘release’ film- entire urinary tract
Full bladder film
Post micturation film
24.
25. In our department
Scout film
5 min film with compression for PCS
15min film with release of compression for ureter
20 min film in prone position (if lower ureter not visualized
in 15 min film)
full bladder
Empty bladder
All films are taken in suspended respiration at end-
expiration.
26. 1 min film (Nephrogram)
Nephrograms are produced
primarily by filtered contrast
material within the nephron,
with optimal visualization of
the renal parenchyma 1–3
minutes after bolus injection.
Features to be seen here are:
Size
Contour
position
Axis of kidney
27. 5 min film
Focused to the renal area
(to assess temporal symmetry
and progress of opacification).
28. Abdominal compression
Applied after 5 min film with compression pad placed
between ASISs (ureters are compressed against the
sacrum as the ureter traverses the sacral ala)
Produces partial ureteric obstruction
Distension of calyceal system
Improved calyceal detail
Reliable ureteric opapification
on release
29. Value of compression. (a) On a radiograph obtained 5 minutes after
administration of low- osmolar urographic contrast material, the
collecting system is bilaterally underfilled and poorly demonstrated.
(b) On a radiograph obtained 5 minutes after compression was applied,
distention of the collecting system is significantly improved (arrows).
30. Contraindications to compression
Urinary tract obstruction
Severe abdominal pain e.g.. Ureteric colic
Abdominal mass or abdominal aortic aneurysm
Recent trauma or abdominal surgery
IVC filter
Presence of urinary diversion e.g.. nephrostomy
Renal transplant
Severe hypertension
31. 15 min film Ureter -bladder images
Full film is taken immediately after release of compression
to visualise ureter and filling bladder
32. Bladder Films
Central ray is angulated by 15
degrees caudally and centered
in midline to a point 5 cm above
pubic symphysis or 2.5 cm
below ASIS.
Exposure is made on suspended
expiration.
33. Post micturation film
Residual urine
Diverticula
Bladder hernia
Bladder tumor
Obstructive urethral lesion
Distal ureteral process e.g.
Ureterocele
Primary mega ureter
34. Additional films
Oblique radiographs
Prone radiograph
Erect radiograph
Full length post- micturation radiograph
Fluoroscopy
35. Patient Aftercare
General psychological reassurance.
Needle wound site dressed and checked for
extravasation.
Tell to patient how to receive the report of
examination
Ensure patient has understood preparation
instructions are finished
36. Examination Effective dose (mSv) Equivalent no. of
chest x-rays
Limbs and joints (except
hip)
< 0.01 <0.5
Chest PA 0.02 1
Skull 0.06 3
Thoracic spine 0.7 35
Lumbar spine 1 50
Hip 0.4 20
Abdomen or Pelvis 0.7 35
IVU 2.4 120
Ba swallow 1.5 75
Ba meal 2.6 130
BMFT 3 150
Ba enema 7.2 360
CT head 2.0 100
CT chest 8.8 400
CT abdomen or pelvis 10 500
37. Micturiting Cystourethrogram/MCU/VCU
Commonly used examination for
UB and urethral evaluation in
both children and adult.
Preliminary abdominal imaging
precedes catheterization. If an
abdominal radiograph obtained
within past 3– 6 months , a scout
image may be unnecessary.
Abdominal radiograph may
reveal bone abnormalities,
calcifications, foreign bodies, or
other disease processes.
38. Indications for VCU in children
Main is UTI, esp. in girls <5 yrs age.
In neonate, MC indication is hydronephrosis detected on
prenatal USG.
To look for VUR (30 – 50% children with UTI have VUR)
For congenital lower urinary tract anomalies.
39. Indications for VCU in adults
Trauma
UTI
To document reflux nephropathy
Evaluation and follow up of in spinal cord injury or voiding
difficulties
Following renal transplantation to see for bladder capacity,
VUR or BOO.
In females to look for urethral diverticula.
40. For catheterization, a 5-F feeding tube is appropriate in
children under 3 months of age and an 8-F feeding tube in
all other children.
In female child, after cleansing intralabial region with
povidone iodine solution, a small drop of solution remains
pooled in midline, depressed, slightly oval meatus, which
thus becomes easily visible. It helps prevent vaginal
catheterization.
In boys, external sphincter is MC site of resistance to
catheter advancement. Gentle, steady pressure rather than
intermittent poking at this level permits advancement into
the bladder.
41. In older boys, retrograde injection of 2% lidocaine jelly into
urethra several minutes before catheterization may be used
to diminish sensation.
Once catheter has safely reached UB, filling with diluted
contrast material can begin.
During early filling, minimally filled bladder is imaged in
AP projection. A ureterocele or bladder tumor well seen
during early filling may become obscured as more contrast
material enters bladder.
42. Older children may indicate when voiding is imminent. In
younger children, as bladder capacity is reached, flow of
contrast material may slow, stop, or even reverse in tubing,
indicating an abrupt rise in intravesical pressure and
complete bladder filling.
At this stage steep oblique images of bladder centered on
UVJ should be obtained.
Bladder Capacity = (Age [Years] + 2) * 30
Volume of contrast instilled should be recorded.
43. URINARY BLADDER CAPACITY (in ml)
ACCORDING TO AGE :
For <2 years-
weight(kg)*7
For>2 to 12 years-
( age(years)+2)*30
For adults around 500ml
44. Male Urethra can also be divided into:
Anterior Urethra-
Penile urethra
Bulbar urethra
Posterior Urethra-
Membranous urethra
Prostatic urethra
45. VUR can be seen on oblique
radiographs obtained just before
voiding and can be graded after
voiding.
If reflux is observed during late
bladder filling, ipsilateral renal fossa
may be imaged in AP projection
prior to voiding.
Catheter may be removed as voiding
is initiated, but voiding around it is
recommended as it allows desired
cyclic voiding in neonates, repeat
filling if needed, and bladder
drainage when unable to empty
bladder completely.
46. Approximately 20% of reflux will be
missed if voiding does not occur.
Urethral disease is very rare in
girls, and one AP image of urethra
is usually sufficient. Voiding while
supine, especially with legs in close
apposition, can produce vaginal
reflux.
In boys, entire urethra must be
imaged in steep oblique position
because disease can occur
anywhere from the bladder base to
the urethral meatus.
After voiding, each renal fossa
should be imaged.
47. Causes of VUR:
Anatomical causes –
Posterior urethral valves(PUV’s)-most common anatomical
cause
Prostatomegaly
Ureteroceles
Ureteral duplication
Neurofunctional causes-
Neurogenic bladder
Dysfunctional voiding
Uninhibited bladder contractions-most common
urodynamic abnormality associated with reflux
48. GRADES OF VUR
GRADE 1-reflux limited to ureter
GRADE2-reflux upto the renal pelvis
GRADE 3-mild dilatation of ureter and pelvicalyceal system
GRADE4-tortuous ureter with moderate dilatation
blunting of fornices with preserved papillary impressions
GRADE5-tortuous ureter with severe dilatation of ureter and
pelvicalyceal system
loss of fornices and papillary impressions
51. GRADE 3-mild dilatation of ureter and pelvicalyceal
system
52. GRADE 4-tortuous ureter with moderate dilatation
blunting of fornices with preserved papillary
impressions
53. GRADE 5-tortuous ureter with severe dilatation of
ureter and pelvicalyceal system loss of fornices and
papillary impressions
54. Points to be assessed and reported by radiologist at end of
examinations:
1. status of spine and pelvis
2. presence of masses or opaque calculi
3. bladder capacity and contour and emptying capability
4. presence and grade of reflux and obstruction of a
refluxing segment
5. insertion site of a refluxing ureter
6. appearance of entire urethra
55. Retrograde urethrography (RGU)
Best initial study for urethral and
periurethral imaging in men, indicated
in evaluation of urethral injuries,
strictures, and fistulas.
Not a physiological examination.
External meatus prepared in standard
sterile fashion for placement of a
conventional 16- or 18-F Foley catheter.
Catheter, with both irrigating syringe
and inflating (saline solution) syringe
attached, should be flushed before use.
When balloon portion of catheter is
seated in fossa navicularis of penile
urethra, balloon is inflated with 1.0–1.5
mL of saline solution.
56. Lubrication not recommended, may prevent balloon
from remaining in place for optimal occlusion.
Patient placed in a supine 45° oblique position, penis
placed laterally over proximal thigh with moderate
traction.
20–30 mL of 60% iodinated contrast material is injected
so that anterior urethra is filled.
Commonly, spasm of external urethral sphincter will be
encountered preventing filling of deep bulbar,
membranous, and prostatic urethras. Slow, gentle
pressure is usually needed to overcome this resistance.
57. Contrast material can seen to jet through
bladder neck into bladder.
Verumontanum seen as ovoid filling defect
in posterior part of prostatic urethra.
Distal end of it marks proximal boundary
of membranous urethra
Identification of bulbomembranous
junction (1–1.5 cm distal to the inferior
margin of verumontanum) on a RGU is
important for assessing patients with
urethral disease as well as for planning
urologic procedures.
With poorly opacified posterior urethra ,
bulbomembranous junction can be
localized by an imaginary line connecting
inferior margins of obturator foramina
intersects urethra.
58. Filming:
Under fluoroscopic control, contrast medium is injected and spot films are
taken in the following positions-
30-degree right anterior oblique with left leg abducted and knee flexed
Supine AP
30-degree left anterior oblique with right leg abducted and knee flexed
59.
60. Anterior urethra extends from its
origin at end of membranous urethra
to urethral meatus, divided into bulbar
segment and penile segment. There is
usually mild angulation of the urethra
where these two segments join at
penoscrotal junction.
Contraction of constrictor nudae
muscle, a deep musculotendinous sling
of bulbocavernous muscle, may cause
anterior or circumferential indentation
of proximal bulbous urethra at RGU
(should not be confused with urethral
stricture)
If the membranous urethra can be
identified, it should not be confused
with a stricture.
61. Narrowing elsewhere in urethra will be
clearly defined as separate from
membranous urethra and, therefore,
representative of a pathologic stricture.
If the patient is not positioned sufficiently
oblique, the bulbous urethra will appear
foreshortened and will therefore not be
adequately evaluated.
Filling of Cowper ducts should not be
misinterpreted as extravasation.
If integrity of urethral mucosal lining is
disrupted by increased pressure during
contrast material injection, intravasation
of contrast material with opacification of
corpora and draining veins may occur.
62. Extravasation: Intramural extravasation
can occur in bladder esp. during voiding,
but is self limited and requires no
treatment.
Inadvertent catheterization of vagina or
ureter: If vagina is catheterized, tubular
shape with reflux into uterus , fallopian
tubes or peritoneal cavity may occur.
Catheter can also enter a ureter with an
ectopic ending, of a double collecting
system or one with a very dilated orifice.
Radiation effect
Autonomic dysreflexia
63. Complication of MCU/RGU
Infections: Bacteria may be introduced via the catheter
and high fever can develop after cystography.
Trauma: Dysuria, urinary retention and penetration of
bladder wall may develop following catheterization.
Reaction to contrast medium: Very rare, when contrast
can get absorbed through bladder wall or from the
ureteral or pyelocalyceal epithelium or intravasation
during RGU.
In children with ventriculoperitoneal shunt, nonionic
contrast is to be used.
Knotting of catheter within bladder
64. Urethral Trauma
Urethral injuries are divided into anterior and posterior
urethral injuries .
Causes:
Blunt Trauma-due to shearing/straddle injuries
posterior urethral injury is caused by a crushing force to
the pelvis and is associated with pelvic fractures and
bladder injury .
anterior urethral injury is usually caused by a straddle
injury and is an isolated injury
Penetrating trauma-due to stab wounds,gunshot wounds
more commonly affects anterior urethra
Iatrogenic-Catheterization,Cystoscopy
Post surgical(surgery for Benign Prostatic Hyperplasia)
65. Retrograde Urethrography is the modality of choice
to investigate the anterior part of urethra .It will
demonstrate extraluminal contrast which has
extravasated from the urethra at the site of injury.
VCUG is the most appropriate way to evaluate the
posterior part of male urethra and injuries to
female urethra.
66. Goldman system for Classification of urethral
injuries:
Type 1-
Stretching of prostatic urethra due to disruption of
puboprostatic ligaments but the urethra is intact.
Urethrographic appearance shows intact but stretched urethra
67. Type 2-
Posterior urethral injury above urogenital
diaphragm while the membranous segment
remains intact .
Urethrographic appearance shows contrast
material extravasation above urogenital
diaphragm only.
68. Type 3-(most common)
Injury to membranous urethra extending into proximal bulbous
urethra(with laceration of urogenital diaphragm).
Urethrographic appearance shows contrast material
extravasation below the urogenital diaphragm,possibly
extending into pelvis or peritoneum with intact bladder neck.
69. Type 4-
Bladder base injury involving bladder neck extending
into proximal urethra.Internal Sphincter is injured
hence incontinence can occur.
Extraperitoneal contrast agent extravasation,bladder
neck disruption
70. Type 4a-
Bladder base injury but not involving bladder
neck .
Cannot be differentiated from Type 4
radiologically.
Periurethral contrast material extravasation
,bladder base disruption.
71. Type 5-
Anterior urethral injury (isolated).
Contrast material extravasation below urogenital
diaphragm in and around penile soft tissue.
72. MCU VS RGU
MCU is performed to demonstrate posterior urethral
abnormalities ,in addition it shows bladder
pathologies and VUR also.
RGU is performed to demonstrate anterior urethral
abnormalities.
In cases of Trauma, RGU is performed before MCU to
avoid more injury while introducing Foley catheter
blindly into bladder.
