a small presentation on GUT covering basic information about the system radiologically

1. Dr. Tarun Goyal
Post Graduate Student
Dept. Of Radiology
SMSnR, Sharda University

2. Esophagus (cut)
Inferior vena cava
Adrenal gland
Hepatic veins (cut)
Renal artery
Renal hilum
Renal vein
Iliac crest
Kidney
Ureter
Urinary
bladder
Urethra
Aorta
Rectum (cut)
Uterus (part
of female
reproductive
system)

3. Urinary System Organs
• Kidneys are major excretory organs
• Urinary bladder is the temporary storage
reservoir for urine
• Ureters transport urine from the kidneys to the
bladder
• Urethra transports urine out of the body

4. K I D N E Y S

5. THE KIDNEYS
Retroperitoneal, in the superior
lumbar region.
Right kidney is lower than the
left
Convex lateral surface,
concave medial surface
Renal hilum leads to the renal
sinus
Ureters, renal blood vessels,
lymphatics, and nerves enter
and exit at the hilum

6. •Renal cortex
A granular superficial region (outer part)
•Renal medulla
The cone-shaped medullary (renal) pyramids separated by
renal columns (inner part)
•Papilla
Tip of pyramid; releases urine into minor calyx
•Renal pelvis
The funnel-shaped tube within the renal sinus
•Major calyces
The branching channels of the renal pelvis that collect urine
from minor calyces
Urine flows from the pelvis to ureter

7. Renal cortex
Renal medulla
Major calyx
Papilla of
pyramid
Renal pelvis
Ureter
Minor calyx
Renal column
Renal pyramid
in renal medulla
Fibrous capsule
Renal
hilum
(a) Photograph of right kidney, frontal section (b) Diagrammatic view

8. Aorta
Renal artery
Segmental artery
Interlobar artery
Arcuate artery
Cortical radiate artery
Afferent arteriole
Glomerulus (capillaries)
Inferior vena cava
Renal vein
Interlobar vein
Arcuate vein
Cortical radiate
vein
Peritubular
capillaries
and vasa recta
Efferent arteriole
Path of BLOOD FLOW through renal blood
vessels

9. Removal of toxins, metabolic wastes, and excess ions from
the blood
Regulation of blood volume, chemical composition, and pH
Gluconeogenesis during prolonged fasting
Endocrine functions
Renin: regulation of blood pressure and kidney function
Erythropoietin: regulation of RBC production
Activation of vitamin D

10. Imaging Modalities For Visualization of Urinary system.
X-Ray KUB
X-Ray KUB
showing B/ L
Kidney Shadow..

11. Relations
a. Posterior: Diaphragm,
12th Rib, Pleura,
Med – Lat: Psoas, QL, TA
b. Superiorly: Adrenals
c. Anterior:
Right: Liver, 2nd part of duodenum,
Asc. colon, SI.
Left: Stomach, Pancreas, Spleen,
SF, Jejunum

12.  Kidney size smaller than on
radiographs – 9-11 cm
 Visualization: Posterolateral,
Lateral or Posterior approach

13. Developmental Anomalies
Duplication of collecting system
– commonest (4%)
Persistent fetal lobulation

14. DROOPING LILY SIGN
A urographic sign in some patients
with a duplicated collecting system. It
refers to the inferolateral
displacement of the opacified lower
pole moiety due to an obstructed
(and unopacified) upper pole moiety.
Horseshoe
kidney
A horseshoe kidney is formed by fusion
across the midline of two distinct
functioning kidneys, one on each side of
the midline. They are connected by an
isthmus of either functioning renal
parenchyma or fibrous tissue.

15. Crossed fused renal
ectopia refers to an anomaly where
the kidneys are fused and located on
the same side of the midline.
Subtypes
type a: inferior crossed fusion
type b: sigmoid kidney
type c: lump kidney
type d: disc kidney
type e: L-shaped kidney
type f: superiorly crossed fused
Pancake kidney is a rare renal fusion
anomaly of the kidneys of the crossed fused
variety. The upper and lower poles of the kidneys
are fused hence giving it an appearance of pancake
and usually give rise to two separate ureters which
enter the bladder in normal relationship

16. Junctional cortical/parenchymal
defects:
Triangular echogenic areas In upper
pole. Represent normal extensions of
renal sinus due to partial fusion of
embryonic renunculi.
DD: Renal Scar, Angiomyolipoma
Hypertrophied Column of
Bertin:
Partial renal duplication of septal
cortex in mid portion of kidney –
pseudo mass appearance
Associated with bifid pelvis.

17. Uncomplicated renal cyst
• well-marginated anechoic lesion
with thin walls
• a few thin septa (5% of cysts)
• the back wall should be visible
• posterior acoustic enhancement -
nonspecific
• a small amount of intracystic
hemorrhage/debris may be present,
and may require further evaluation
Complicated renal cyst
• cystic lesions with thickened or
irregular walls or septa
(suspicious for renal cell
carcinoma and warrant further
work up)
• vascularity of the septa on color or
spectral Doppler is suspicious for
renal cell carcinoma

18. HYDRONEPHROSIS
Hydronephrosis is defined as dilatation of the
urinary collecting system of the kidney (the
calyces, the infundibula, and the pelvis).
The term hydroureteronephrosis (or
hydronephroureterosis) is used when the
dilatation also involves the ureter.

19. GRADE 1 GRADE 2
GRADE 3Typical B-mode findings of a long-standing severe
CKD:
•reduced renal cortical thickness <6 mm
•reduced renal length
•increased renal cortical echogenicity
•poor visibility of the renal pyramids and the renal
sinuses marginal irregularities
•papillary calcifications
•cysts
Chronic kidney disease

20. USG Findings…
 particulate matter/debris in the collecting system
 reduced areas of cortical vascularity by using power Doppler
 gas bubbles (emphysematous pyelonephritis)
 abnormal echogenicity of the renal parenchyma
 focal/segmental hypoechoic regions (in edema) or
hyperechoic regions (in hemorrhage)
 mass-like change
Pyelonephritis

21. Urolithiasis refers to the presence of
calculi anywhere along the course of the
urinary tracts.
The composition of urinary tract stones
varies widely depending upon metabolic
alterations, geography and presence of
infection, and their size varies from
gravel to staghorn calculi.
The more common composition of
stones include (more detail below):
Calcium oxalate +/- calcium phosphate:
~75%
Struvite (triple phosphate): 15%
Pure calcium phosphate: 5-7%
Uric acid: 5-8%
Cystine: 1%

22. Radiographic features
These depend on stone composition and vary according to modality. The
much greater sensitivity of CT to tissue attenuation means that some
stones radiolucent on plain radiography are nonetheless radiopaque on
CT.
Abdominal radiography
Calcium-containing stones are radiopaque
Calcium oxalate +/- calcium phosphate
Struvite (triple phosphate) - usually opaque but variable
Pure calcium phosphate
Lucent stones include
Uric acid
Cystine
Indinavir stones
Pure matrix stones (although may have a radio dense rim or centre )

23. Ultrasound
Ultrasound is frequently the first investigation of the urinary tract, and
although by no means as sensitive as CT, it is often able to identify calculi.
Small stones and those close to the corticomedullary junction can be difficult
to reliably identify. Ultrasound compared to CT KUB reference showed a
sensitivity of only 24% in identifying calculi. Nearly 75% of calculi not
visualized were <3 mm.
Features include:
1. Echogenic foci
2. Acoustic shadowing
3. Twinkle Artifact on color Doppler
4. Color comet tail artifact

24. Kidney calculus

25. Computed tomography of kidneys,
ureters and bladder (CT KUB) is a
quick non-invasive technique for
diagnosis of urolithiasis. It is usually
considered the initial imaging
modality for suspected urolithiasis
in an emergency setting.
Advantages
1. Quick
2. Easily accessible
3. Identification of calcified renal
tract calculi and their sequelae
4. Assessment of other causes of
flank pain if negative for calculus
disease
Disadvantages
exposure to ionizing radiation

26. Findings:
1. Identification of calcified renal tract calculi size and position.
2. Stone composition assessment with dual energy CT.
3. Assessment of the sequelae of calculi
• obstruction
• infection
4. Assessment of other causes of flank pain if negative for calculus
disease
5. Presence of further calculi at risk of obstructing.
Normal KUB
CT
obstructing
right ureteric
calculus

27. Intravenous urography (IVU), also referred as intravenous
pyelography (IVP) or excretory urography (EU), is a
radiographic study of the renal parenchyma, pelvicalyceal
system, ureters and the urinary bladder
Indications
1. Check for normal function of
kidneys
2. Check for anatomical variants or
congenital anomalies (e.g. horse-
shoe kidney)
3. Check the course of the ureters
4. Detect and localise a ureteric
obstruction (urolithiasis)
5. Assess for synchronous upper
tract disease in those with bladder
transitional cell carcinoma(TCC)

28. Technique
1. Exposures of 65-75 kV range, mA of 600-1000, with exposure of
<0.1 sec. Higher kV ranges reduce contrast of the renal
parenchyma.
2. IV access for water soluble contrast, nonionic contrast is
preferred
3. Dose vary as per weight of the patient; generally up to 1.5 ml/kg
body weight is well tolerated by patient
4. The calyces are usually visualized in <2 minutes following
contrast administration - this is the Nephrogram
5. Serial images are taken at 5-20 minutes for visualization of the
pelvicalyceal systems and ureters when required and with
operator preference
6. Additional views taken are prone and oblique for ureters
7. The full length 10-15 minute film is performed.
8. Lastly take a full bladder and post void film

30. The ureter is a paired fibro muscular
tube that conveys urine from
the kidneys in the abdomen to
the bladder in the pelvis.
Gross anatomy
The ureter is 25-30 cm long and has
three parts:
1. Abdominal ureter: from the renal
pelvis to the pelvic brim
2. Pelvic ureter: from the pelvic brim
to the bladder
3. Intravesical or intramural
ureter: within the bladder wall

31. Constrictions
The ureter has a diameter of 3 mm but there are three constrictions,
which are the most common sites of renal calculus obstruction:
1. at the pelviureteric junction (PUJ) of the renal pelvis and the ureter
2. as the ureter enters the pelvis and crosses over the common iliac
artery bifurcation
3. at the vesicoureteric junction (VUJ) as the ureter obliquely enters the
bladder wall

32. Relations:
Abdominal ureter
Following the course of the ureter from
superior to inferior:
 Posteriorly: psoas muscle; genitofemoral
nerve; common iliac vessels; tips of L2-L5
transverse processes
 Anteriorly
 Right ureter: descending duodenum,
gonadal vessels; right colic vessels;
ileocolic vessels
 left ureter: gonadal artery; left colic
artery; loops of jejunum; sigmoid
mesentery and colon
 Medially
 Right ureter: IVC
 Left ureter: abdominal aorta,
inferior mesenteric vein

33. Developmental anomalies
a. Duplication: commonest
significant congenital anomaly
of urinary tract. Commoner in
females.
b. Weigert-Meyer law: during complete
duplication, ureter serving the upper
renal moiety drains fewer calyces
and is inserted lower into the bladder
than that draining the lower moiety –
maybe as low as the bladder neck.
Upper moiety – obstruction
Lower moiety – reflux
An ectopic ureter is a congenital renal anomaly that
occurs as a result of abnormal caudal migration of the
ureteral bud during its insertion to the urinary bladder.
Normally the ureter drains via the internal ureteral orifice
at the trigone of the urinary bladder.

34. Ureteroceles represent congenital dilatation of the distal-most portion of
the ureter. The dilated portion of the ureter may herniated into the
bladder secondary to the abnormal structure of vesicoureteric junction
(VUJ)
Location:
1. Intravesical: occur at the normal VUJ position
2. Extravesical: occur ectopically low and medial, near bladder
neck/urethra
On IVP
Detectable findings include:
1. filling defect in the bladder
(cobra head sign) which may
be distended, collapsed or
even everted
2. radiolucent halo effect
3. an everted ureterocele will
appear like a bladder
diverticulum
B/L Ureteroceles

35. A stone will be identified as
an echogenic focus with
sharp, distal acoustic
shadowing within the
ureteric lumen.
There may be associated
mucosal edema at the
bladder trigone.
At gray-scale ultrasound, a
stream of low-level echoes
can be seen entering the
bladder from the ureteral
orifice.
On USG

36. COLOUR DOPPLER STUDY OF
U.BLADDER IN URETERIC CALCULUS

37. The urinary bladder is a distal part of
the urinary tract and is an extra
peritoneal structure located in the
true pelvis. Its primary function is as
reservoir for urine.
MRI showing UB in females
UB in males
U. Bladder is relatively fixed inferiorly via
a. condensations of pelvic fascia, which
attach it to the back of the pubis, the
lateral walls of the pelvis and the
rectum
b. continuity with the prostate in male -
strong puboprostatic ligaments

38. Relations - Male
•Anteriorly: pubic symphysis
•Posteriorly: rectovesical pouch
and rectum
•Inferiorly: prostate, obturator
internus muscle, levator ani
muscle
•Superiorly: peritoneum
•Laterally: ischioanal fossa
Relations - Female
•Anteriorly: pubic symphysis
•Posteriorly: vesicouterine
pouch, uterus, cervix, vagina
•Inferiorly: pelvic fascia, perineal
membrane
•Superiorly: uterus, peritoneum
•Laterally: ischioanal fossa

39. Bladder Agenesis
Bladder agenesis is a rare anomaly. Most infants with bladder
agenesis are stillborn; virtually all surviving infants are female.
Many associated anomalies are often present. At ultrasound, the
bladder is absent.
Bladder Exstrophy
Bladder exstrophy occurs in 1 in 30,000 live births, with a 2 : 1
male predominance. Failure in development of the mesoderm
below the umbilicus leads to absence of the lower abdominal
and anterior bladder wall. These patients have an increased (200-fold)
incidence of bladder carcinoma (adenocarcinoma in 90%).
Bladder Fistulas
can be congenital or acquired. Causes of acquired
fistulas include trauma, inflammation, radiation, and neoplasm. At
ultrasound, appears as a nondependent linear echogenic focus with distal
dirty shadowing. Palpation of the abdomen during scanning
may cause gas to percolate through the fistula, enhancing its detection.

40. Double U.Bladder: receives
ipsilateral ureter and has
separate urethra.

41. Infectious Cystitis
Women at high risk for cystitis because of colonization of the short
female urethra by rectal flora. Bladder outlet obstruction
or prostatitis results in cystitis in men.
Mucosal edema and decreased bladder capacity are common.
The most common finding at sonography is diffuse bladder wall
thickening.
If cystitis is focal, pseudopolyps may form, which are impossible to
differentiate from tumor
.

42. Chronic Cystitis
Chronic inflammation of the bladder.
It may result in invagination of solid “nests” of urothelium into the
lamina propria (Brunn epithelial nests), which may result in
morphologic changes that mimic neoplasia.
Cystitis cystica and cystitis glandularis may be manifested at
ultrasound as bladder wall cysts or solid papillary masses .
Because the appearance of these conditions on imaging can be
mistaken for malignancy, cystoscopy with biopsy is necessary for
diagnostic confirmation

43. Cystitis

44. Bladder calculi occur either from
migrated renal calculi or urinary stasis.
Bladder calculi can be divided into
primary and secondary stones:
1. Primary: stones form de novo in
the bladder
2. Secondary: stones are either
from renal calculi which have
migrated down into the bladder,
from concretions on foreign
material (e.g. urinary catheters)
Radiographic features:
Plain radiograph
Usually densely radiopaque, calculi
may be single or multiple and are
often large. Frequently lamination is
observed internally, like the skin of
an onion.
Ultrasound
Sonographically they are mobile,
echogenic, and shadow distally.
They may be associated with
bladder wall thickening due to
inflammation.

45. weighs between 20-40 grams with
an average size of 3 x 4 x 2 cm
The seminal vesicles are
superior and posterior to the
prostate gland.
Their ejaculatory ducts pierce
the posterior surface of the
prostate below the bladder.
The prostate is comprised of 70%
glandular tissue and 30%
fibromuscular /stromal tissue
The prostate is comprised of
three distinct zones with
different embryologic origins:
1. Peripheral zone
2. Central zone
3. Transition zone
Development
Central zone: Wolffian duct
Transition zone: Urogenital sinus
Peripheral zone: Urogenital sinus

46. Ultrasound
best assessed with transrectal ultrasound
some zonal anatomy distinguishable
outer gland (central and peripheral zones)
- uniform low echogenicity but usually
more echogenic than the inner gland
25cc is a commonly used upper limit for
normal volume
MRI preferred imaging modality
T1: Homogenous intermediate signal intensity
T2:
•Anterior fibromuscular stroma is low T1W
and T2W signal
•Peripheral zone is high T2W signal, similar to
or greater than adjacent fat
•There are age-related decreases in T2W
signal
•Central and transition zones are lower T2W
signal than peripheral zone

47. Prostatic calcificationis a
common finding in the prostate gland,
especially after the age of 50. They may
be solitary but usually occur in clusters.
Variable appearance from fine granules to
irregular lumps
Prostatic utricle cyst (PUC) is
an area of focal dilatation that occurs
within the prostatic utricle.
They are midline cystic masses in the
male pelvis and can be very difficult or
impossible to distinguish from
a Mullerian duct cyst.
Seen as midline prostatic cyst on
MRI

48. extremely common condition in elderly men and is
a major cause of bladder outflow obstruction.
Present with lower urinary tract symptoms
(LUTS) including:
1. Poor stream despite straining
2. Hesitancy, frequency and incomplete emptying
of the bladder
3. Nocturia
An enlarged prostate may also be incidentally
found on imaging of the pelvis or on rectal exam.
Benign prostatic hyperplasia is due to a
combination of stromal and glandular hyperplasia,
predominantly of the transition zone (as opposed
to prostate cancer which typically originates in the
peripheral zone).

49. Radiographic features
Ultrasound
1. The standard first line investigation after the urologist's finger.
2. Increase in volume of the prostate with a calculated volume exceeding 25
mL (width x height x length x 0.52)
3. The central gland is enlarged, and is hypoechoic or of mixed echogenicity
4. Calcification may be seen both within the enlarged gland as well as in the
pseudocapsule (representing compressed peripheral zone)
5. Post-micturition residual volume is typically elevated
Fluoroscopy
On IVP, the bladder floor can be elevated and the distal ureters lifted medially
(J-shaped ureters or fishhook ureters). Chronic bladder outlet obstruction can
lead to detrusor hypertrophy, trabeculation and formation of bladder
diverticula.
MRI
enlarged transition zone, heterogeneous signal with an intact low signal
pseudocapsule in the periphery

50. Urethrographyrefers to the
radiographic study of the urethra using
iodinated contrast media and is generally
carried out in males.
When the urethra is studied with instillation of contrast into
the distal/anterior urethra it has been referred to as
1. Retrograde urethrography (RUG)
2. Ascending urethrography (ASU)
When the posterior urethra is studied during micturation,
this has been referred to as
1. Voiding cystourethrography (VCUG)
2. Descending urethrography
3. Micturating urethrography

51. Examination technique (RUG/ASU)
1. Retract the foreskin and clean the tip of penis with betadine or antiseptic
solution
2. Inject a small amount of topical local anesthetic (e.g. lignocaine gel) into the
urethra with a syringe
• local anaesthetic helps to relax the sphincter as the patient may
contract it during the procedure thus leading to a diagnosis of a
stricture
3. Patient position should be oblique to visualise full length of urethra
4. Place the tip of the metallic adaptor into the urethral orifice and attach the
contrast loaded syringe to it
• an alternative is to place a Foley catheter tip in the navicular fossa and
gently inflate the balloon with sterile water until a seal is formed
making sure not to cause the patient pain or damage the distal urethra
5. Inject the contrast and image as soon as a major part of the contrast has
been injected, taking spot images when appropriate
6. Ideal images demonstrate the entire length of the urethra with contrast
beginning to fill the bladder.

52. Normal
RUG

53. Voiding cystourethrography (VCUG),also known
as Micturating cystourethrography (MCU), is a
fluoroscopic study of the lower urinary tract in which contrast is
introduced into the bladder via a catheter.
Purpose of study:
The purpose of the examination is to assess the bladder, urethra,
postoperative anatomy and micturition in order to determine the
presence or absence of bladder and urethral abnormalities,
including vesicoureteral reflux (VUR).
Neurogenic Bladder
VUR
N

54. RGU VCUG
Pelvic Trauma Urinary tract infection
Diminished urinary stream Dysuria
Urethral strictures Dysfunctional voiding
Urethral diverticula Hydronephrosis/hydroureter
Urethral obstruction Bladder outlet obstruction
Suspected urethral foreign bodies Haematuria
Urethral mucosal tumors Trauma
Suspected urethral fistula Incontinence
Neurogenic dysfunction of the
bladder, e.g. spinal dysraphism
Congenital anomalies of the
genitourinary tract
Postoperative evaluation of the
urinary tract
INDICATIONS

55. RUG/ASU vs. VCUG/MCU
1. Generally, a RUG/ASU is carried out to visualize anterior
urethral abnormalities and a VCUG/MCU for posterior
urethral abnormalities.
2. Additionally, although the bladder is not generally the main
target of the exam, as with a cystogram, a VCUG/MCU may
be useful in detection of bladder abnormalities and vesico-
ureteric reflux (VUR).
3. In a trauma situation, an RUG/ASU should be performed
first. A VCUG/MCU should not be performed first because
blindly trying to introduce a Foley catheter into the bladder
in a trauma setting may lead to creating additional urethral
damage with the catheter.