by dr. satish pathak md dnb professor in radiodiagnosis

BY
DR. SATISH PATHAK
MD DNB
PROFESSOR IN RADIODIAGNOSIS
MAMATA MEDICAL COLLEGE
KHAMMAM-AP
Wilhelm Conrad
Roentgen
Discovered X-ray
In NOV 1895
Awarded First
Noble prize in
Physics in the
Year 1901
Plain Skiagram of Abdomen
Intravenous Urography
Ultrasonography And Color doppler
CT Scan
Angiography
MRI
SPECT & PET
The Kidney:
 A pair of bean-shaped organs approximately 9-12 cm
long; 5-7.5cm average breadth; width 2.5cm
 Retroperitoneal organ extending from T12 to L4 when
the body is in the erect position.
 The right kidney is positioned slightly(1.5cm) lower than
the left because of the liver.
 Renal hilum: most medial portion of kidney giving
entrance/exit to vessels and nerves.
 Anterior to posterior structures in hilum
 Renal vein
 Renal artery
 Ureter
 Lymphatic and sympathetic fibres
 Fat(renal sinus fat)
Bean Shaped
Retroperitoneal
Structure
Internal structure
Within the dense, connective
tissue of the renal capsule, the
Kidney substance is divided into
an outer cortex and an inner
Medulla.
Cortex-contains glomeruli,
Bowman's capsules, and
proximal and distal convoluted
tubules.
•It forms renal columns of
bertin, which extend between
medullary pyramids.

Medulla-consists of 8 to
16 striated pyramids
and contains collecting
ducts and loops of
Henle. The apex of
each pyramid ends as
a papilla where
collecting ducts open.
 The kidney is bound
externally by a tough
fibro-elastic capsule(not
visible on imaging).



Calyces-each minor
calyx receive one papillae
2 or more adjacent minor
calyces unite to form
major calyx, of which
there are two to three per
kidney.
Renal pelvis-the dilated
upper portion of the ureter
that receives the major
calyces.
 Usually intra renal but can
be extra renal
History
Abdominal Preparation
Positioning
Exposure Factors

The renal edge may be visible, outlined by the
perirenal fat. Intrarenal anatomy is never
visible.
 Non-opacified ureters are
never seen on KUB
 Kidneys are about 11-15
cm( 3.5 vertebral bodies)
in length.
 Left kidney is higher and
longer than right kidney
due to liver on right side

Bladder may be outlined by
the perivesical fat
 Plain radiography is
mainly useful for urinary
tract calculi. It is, however,
Only 50% accurate for
Ureteric Calculi, so
extremely unreliable for
ureteric calculi

Assessment of urinary tract including
renal parenchyma, calyces and pelvis
after intravenous injection of contrast
 There is a decline in the number of
intravenous urograms done over the last
decade because of the newer imaging
modalities like CT and ultrasound.
 Low Kv(65-75), high mA(600-1000) and
short exposure time should be used to
get optimum contrast.
Indications










To see the anatomy and physiology of
urinary system
Trauma
Calculi- renal, ureteric, bladder
Congenital anomalies- ectopic kidney,
horseshoe kidney, renal agenesis
Infective pathology
Renal tumour
Unknown Haematuria
Renal hypertension
Bladder pathology- diverticula, fistula
Vesico ureteric reflux
Contraindications:

Hypersensitivity to iodinated CM
 Renal insufficency
 Hepato renal syndrome
 Thyrotoxicosis,
 Pregnancy, (Allow 28 days from
childbirth)
Procedure & Preparation
•Appointment
•Bowel preparation
•Pt comes NBM
•LO non ionic Contrast
50- 100ml ‒Adult
1ml/kg ---paediatric
•300mgI/kg
•600mgI/ kg
Films

Plain
KUB/scout
film
/preliminary film
 Supine, full length AP of
abdomen in inspiration.
 The lower border of cassette
is at the level of symphysis
pubis and the x-ray beam is
centered in the midline at the
level of iliac crests.
 Purpose:
To demonstrate
bowel preparation, check
exposure factor, and location
of radio-opaque stones or any
radio-opaque artifacts.
Films





Immediate film :
AP of the renal areas10”x12” film
This film is exposed 1014 s after the injection
(app. Arm to kidney
time)
Aims to show the
nephrogram, i.e renal
parenchyma opacified
by contrast medium in
renal tubules.
Note: all the films are
taken in full expiration
only

5-min film:
 cross kidney AP film-10?x 12?
 To determine if excretion is symmetrical and is
invaluable for assessing the need to modify the
techinque, eg a further injection of CM if there has
been poor initial opacification.
Classical series of films


Abdominal Compression band is applied over
distal ends of ureters to retard flow of opacified
urine into bladder and to produce better
pelvicalyceal distension.
Compression is
contraindicated: After recent abdominal
surgery, renal trauma, aortic aneurysm, When
the 5-min film shows already distended calyces
Classic series of films

15 min film:
 cross-kidney film-15”x12”
 There is usually adequate
distension of the
pelvicalyceal systems
with opaque urine by this
time.
 Compression is released
when satisfactory
demonstration of the
pelvicalyceal system has
been achieved.
Classical series of films

Full length Release
film:
 Taken immediately after
removing the
compression band
 Demonstration of
ureters optimally
 Partial visualization of a
non-obstructed but
otherwise normal ureter
is acceptable

Post void film
Either a full length abdominal film or
a coned view of the bladder with the
tube angled 15° caudad and
centred 5 cm above the symphysis
pubis based on earlier findings.
 Main aim of films is to
 Assess bladder emptying
 VUR
 Aid diagnosis of intra-lum. &VUJ
calculi
 Post void Residual volume of urine.
Additional films:IVU modifications



Posterior obliques of
kidneys, ureters or
bladder:
To determine whether the
radiopaque shadow is in
the ureter or outside.
Position: Pt. is rotated
30-35° in rt or lt side
depending on pathology
side.
IVU modifications






Prone film:
Better visualization of ureters
To investigate pelviureteric and ureteric obstruction as
the heavy contrast laden urine will more readily
gravitate to the site of the obstruction.
To displace the overlying bowel gas towards periphery.
Position: Pt. lies prone after doing 15 min full film and
after 4-5 min. of lying prone (so that lower ureter is
dependent part) full film is taken.
There are several other modifications depending on
the findings and clinical pathology.
Advantages


The strengths of urography are:
rapid overview of the entire urinary tract,

detailed anatomy of the collecting system,

demonstration of calcifications,

it is sensitive for obstruction, and

low cost,
Disadvantages





it depends on kidney function,
it provides little assessment of
parenchymal structure (eg. cystic vs. solid),
the perinephric space is not demonstrated,
it necessitates the use of radiation and
contrast medium, and
it provides no assessment of glomerular
filtration rate.




USG
 The most frequently performed radiological
investigation of the urinary system.
 Useful for both diagnostic and therapeutic procedures
Patient preparation: none
Transducer:
 broad band high frequency probe for thin and
pediatric patients.
 Low frequency(2-6MHz) for abdomen and pelvis
work
Patient position:
 conventionally-lateral position with the side of interest
uppermost.
 Complementary views: anterior, posterior oblique,
prone.
Approach to Scanning
LIVER
STOMACH
I
AORTA
K


Right kidney scanning
approach: anterior,
lateral, posterior
Liver is the acoustic
window
IVC
S


K
Left kidney: requires a
posterior approach, through
the spleen
Air-filled bowel impedes
anterior scanning
Sonographic Appearance

Renal sinus is most echogenic part due to fat
 Renal pelvis is echo free structure within the
renal sinus when visible esp. with full bladder in
females
 Cortex is mid-gray, less echogenic than liver or
spleen.
 Medullary pyramids are hypoechoic compared to
renal cortex
 Capsule is smooth and echogenic
 Ureters are normally
not seen
Right Kidney Long Axis
Anterior
Superior
Inferior
Liver
Sinus
Cortex
Diaphragm
Posterior
Normal right kidney(long axis)
pyramid
Renal cortex
Arcuate artery
capsule
renal sinus
Left Kidney Long Axis
Anterior
Inferior
Superior
Rib
Shadow
Kidney
Posterior
Spleen
LEFT KIDNEY-
LONG AXIS
Seeking posterior
approach may be
More rewarding.
Neonatal kidney
pyramid
Renal cortex
Column of Bertin
Note: Renal
pyramids
Can be Confused
with cysts in
Pediatric
age group
Renal dimensions




Length of normal kidney: 9 ? 14 cm
Right kidney smaller than left kidney
Discrepancy > 2 cm between two kidneys:
Considered significant & needs further evaluation
Renal length between 8 ? 9 cm
Correlated to patient’s phenotype particularly height
Renal length < 8 cm definitely reduced
Should be attributed to chronic renal failure
Fiorini F et al. J Ultrasound 2007 ; 10 : 161 ? 167.
Normal Variants





Dromedary humps:
 Lateral kidney bulge, same echogenicity as the
cortex
Persistent fetal lobulation:
 Renal surface indentations between pyramids
Hypertrophied column of Bertin:
 Cortical tissue indents the renal sinus
Double collecting system:
 Sinus divided by a hypertrophied column of Bertin
Junctional fusion defect:
Dromedary hump
Common renal variation
•Focal bulge on lateral border of left kidney
•Result from adaptation of renal surface to adjacent spleen
•Easily differentiated from renal mass by Doppler
Paspulati RM et al. Ultrasound Clin 2006 ; 1 : 25 ? 41.
Persistent fetal lobulation
Renal surface indentations between pyramids
May be single or multiple
Mistaken for renal scarring
Paspulati RM et al. Ultrasound Clin 2006 ; 1 : 25 ? 41.
Prominent column of Bertin (PCB)
Mistaken for intra-renal tumor
•Continuity with renal cortex
•Similar echo pattern as renal parenchyma
•Similar vascular pattern by color & power Doppler
Paspulati RM et al. Ultrasound Clin 2006 ; 1 : 25 ? 41.
Junctional fusion defect
Mistaken for cortical scar or angiomyolipoma
Triangular hyperechoic structure
Antero-superior or postero-inferior
surface of kidney
Continuity with central sinus
by echogenic line
?inter -renicular septum?
Paspulati RM et al. Ultrasound Clin 2006 ; 1 : 25 ? 41.




Challenging test to perform owing small size, their depth and
variation in anatomy.
Research suggests that 95% of the main renal arteries can be
adequately examined in adults
The key to renal doppler is accurate demonstration of the
vascular anatomy, which requires knowledge of normal
anatomy, normal and abnormal waveforms
Other imaging modalities to assess renal vessels
 Catheter angiography-gold standard but invasive
 Computed tomographic angiography
○ High resolution than MRA but requires contrast administration
○ C/I in renal failure
 Magnetic resonance angiography ( expensive, time consuming)
Advantages of renal doppler

Doppler sonography is inexpensive,
noninvasive and doesn't require
contrast material.
 Provides both physiological and
anatomical information
 Assess the need for intervention
 Clarifies uncertain or indeterminate CTA
or MRA
Protocol
• The renal doppler includes complete evaluation of kidneys,
survey of aorta from celiac artery to iliac bifurcation with both
gray-scale and color flow doppler, PSV measurements for aorta at
the level of renal arteries to determine renal artery-aorta velocity
measurements.
• pulsed doppler waveforms are obtained from






Aorta
Ostium of main renal artery
mid segment of renal
artery
Hilum of kidney
Segmental arteries
 Upper pole of kidney
 Middle pole of kidney
 Lower pole of kidney
Norma right renal artery
Transverse gray scale
image
Right main renal artery
Transverse color Doppler
image
Right main renal artery
Moukaddam H et al. Ultrasound Clin 2007 ; 2 : 455 ‒ 475.
Normal left renal artery
Gray scale image
Color Doppler image
Proximal main left renal artery
Proximal main left renal artery
Moukaddam H et al. Ultrasound Clin 2007 ; 2 : 455 ‒ 475.
Axial scan in left lateral decubitus
Using right kidney as acoustic window
Schematic drawing
Color Doppler US
Right main renal artery & vein
Meola M et al. J Ultrasound 2008 ; 11 : 55 ‒ 73.
R
E
N
A
L
A
R
T
E
R
I
A
L
S
Y
S
T
E
M
Blood supply





The main renal artery divides into
segmental arteries near hilum
First division is posterior segmental ar.
The main renal artery then divides into
4 segmental br. near the hilum(apical,
upper, middle and lower anterior)
Segmental arteries divide into lobar
arteries.
Lobar arteries divide into interlobar
arteries(lie between pyramids/lobes
 These branch into arcuate arteries that
run along the base of pyramids
 Arcuate
interlobular ar.
Afferent
arterioles
Normal segmental & interlobar renal arteries
Color Doppler image of the kidney
Normal segmental renal arteries (long arrows)
Normal inter-lobar renal arteries (short arrows)
Moukaddam H et al. Ultrasound Clin 2007 ; 2 : 455 ‒ 475.
Renal angiogram
MDCT RENAL
ANGIOGRAM
Renal vein and lymphatic drainage



Kidney is mainly drained by single main renal vein.
Left renal vein is 3times longer than right renal vein,
which passes anterior to aorta to drain into IVC(8095%)
Common variants: circumarotic 7-9%
retroaortic 2-3%
Left renal vein has 3 tributaries: joined by left adrenal
vein, left gonadal vein and lumbar veins, none for
RRV.
 Unlike arterial system, multiple communications exist
between the renal segments within venous system.
 Lymphatic drainage: follows arteries to the paraaortic lymph nodes.
Largely replaced by MDCTA & MRV
Indications
To confirm diagnosis of RVT prior to thrombolysis.
To evaluate anatomical variations prior to IVC filter
placement.
Prior to portal HT surgery for spleno-renal shunt
surgery.
To define renal venous anatomy in renal transplant
donors.
Spaces Around the Kidney


Perirenal Space ‒ bounded by the Gerota’s fascia
which fuses superiorly, laterally and medially
Fascia encloses the kidneys, adrenal glands, renal
vasculature and proximal ureter


The fascial envelope is functionally open caudally just
above the pelvic brim
Ureter emerges from the peri-renal space and traverses
caudad in anterior pararenal space
Gerota’s fascia ‒ anterior
fuses in front of the great
vessels with the
contralateral anterior renal
fascia
Zuckerkandle’s fascia ‒
posterior passes behind
the kidney to merge with
the fascia of quadratus
lumborum and psoas
major, to attach to the
vertebral column.
Both Fuse laterally
to form the lateral-conal
fascia.
RENAL FACIA
AND SPACES
ADRENALS
&
URETERS
Ureters:

Connects renal pelvis to the
bladder
 25-30cm long
 3mm in diameter
 Courses inferiorly over psoas.
 Normally, three
?functionally? narrow
regions exist along the
course of each ureter .
Urinary Bladder

U.Bladder is situated in the anterior part of the pelvic
cavity, behind and just above the symphysis pubis.
 Exact position depends on the degree of distension.
 Acts as a reservoir for urine from the kidneys and
subsequently expels it via the external urethra.
 It is a hollow muscular organ lying in the anterior
part of the pelvis outside the peritoneum.
The ureters enter the postero lateral angles of the
base and the urethra leaves inferiorly at the narrow
neck.
Urinary Bladder
The interior of the
bladder is covered with
mucous membrane
thrown into folds,
except in the trigone
between the ureteric
orifices.
USG and CT are the
primary imaging
methods for evaluation.
MRI has limited role.
Patient is asked to drink 1lit. Of
water 20 min. before procedure
First un-enhanced phase
obtained.
40ml. Of 300mgI/ml non-ionic
CM at the rate of 2ml/sec.
 After a delay of 4-8min.
Additional 80mi of contrast
injected at the rate of 2ml/sec.
After a delay of 120sec/3min.
IInd contrst enhanced phase of
Synchronus nephrographic and
Pyelographic phase is obtained
Striated paint brush
appearance in renal
tubular ectesia
Static fluid MR Urography
Excretory T1 MR Urography
Static fluid MR Urography
Most common MR means of evaluating urinary tract.
SFMR urography treats urinary tract as static column
Of fluid.
Uses one of the varieties of T2W sequence utilizing
Long T2 relaxation time of urine.
Sequence like HASTE which are also utilized in MRCP
Are used to obtain the images. Others like SSFSE are
Also utilized.
3D respiratory gated sequence for creating MIP and
VRT images.
Excretory T1 MR Urography
It is analogous to CT urography.
Gadolinium bases contrast is injected IV
Adequate hydration improves distensibility of the
Urinary tract.
Low dose Diuretics are also helpful in improving
distensibility and and delineation of the urinary tract
Sequences like LAVA, VIBE, THRIVE are utilized
For adequate fat suppression and obtaining images
Of urinary tract.
Normal urinary system on nuclear
medicine imaging
The techniques used in
Nuclear Medicine involve
labelling of a specific
molecule with a radioactive
atom; a quantity of which is
administered to the patient.
The labelled molecules follow
their specific biochemical
pathways inside the body. The
atoms used are radioactive
and undergo random decay,
emitting gamma ray photons.
Photons are detected outside
the body by the detector NaJ(Tl) crystal- of the gamma
camera.
PET_CT scanning
Normal bladder
Normal kidneys
The PET/CT systems now in wide clinical use combine a multidetector PET system with a
multidetector computed tomography (CT) scanner in a single unit