Radiological examination of the urinary tract and retro-peritoneal space.

1
Radiological examination of the urinary tract and
retro-peritoneal space.

• DEPARTMENT OF ONCOLOGY AND RADIOLOGY
• PREPARED BY I.M.LESKIV

2
RENAL STRUCTURE AND FUNCTION

• The kidneys control the volume, composition, and
  pressure of body fluids by regulating the
  excretion of water and solutes. They also
  influence red cell production and blood pressure
  by hormonal mechanisms. Urine is formed in the
  kidneys as an aqueous solution containing
  metabolic waste products, foreign substances, and
  water-soluble constituents of the body in
  quantities depending upon homeostatic needs.

3
Anatomy

• The kidneys are bilateral, retroperitoneal
  structures, each consisting of an outer cortex
  and an inner medulla. The medulla is arranged
  into several cone-shaped or pyramidal
  projections separated from each other by sections
  of cortex called renal columns. The bases of the
  pyramids face the cortex of the kidney while the
  apices (papillae) point toward the hilus and
  project into the renal pelvis. The cortex
  contains glomeruli and tubules the medulla,
  tubules only.
• The kidneys possess numerous blood vessels and
  because of their low vascular resistance receive
  approximately 1200 ml of blood or 25 of the
  cardiac output each minute.
• The major resistance to blood flow occurs in the
  glomerular capillary bed and is produced by a
  relatively high resistance in the efferent
  arterioles. However, changes in renal arterial
  pressure produce proportional variations in the
  afferent arteriolar resistance, which tends to
  preserve a constant renal blood flow (RBF) and
  glomerular capillary pressure i.e.,
  autoregulation. In addition to autoregulatioaj
  the renal circulation is controlled by extrinsic
  factors such as neurogenic (sympathetic) and
  hormonal (epinephrine, norepinephrine, and
  angiotensin) regulators. I

4
Sagittal section of the kidney. The upper half
depicts the overall gross anatomic arrangement
The lower half demonstrates the arterial supply.
5

• The Nephron
• The basic functional unit of the kidney is the
  nephron, a long tubular structure made up of
  successive segments of diverse structure and
  transport functions. It includes (1) a renal
  corpuscle (Bowman's capsule and the glomerulus, a
  tuft of capillaries), (2) a proximal tubule
  (convoluted and straight portion), (3) a hairpin
  loop (Henle's loop), (4) a distal tubule
  (straight portion, macula densa, and convoluted
  portion), and (5) a collecting duct system. There
  are approximately one million nephrons in each
  human kidney 85 are cortical nephrons with
  short loops of Henle, and 15 are juxtamedullary
  nephrons with glomeruli near the cortical
  medullary junction and with long, thin, looping
  segments

6

• The Concept of "Clearance" and the Measurement of
  GFR
• A principal function of the kidney is to remove
  or "clear" various solutes from the blood which
  are not essential to the body, and to conserve
  those that the body requires. A solute is never
  totally removed from the blood in any one passage
  through the kidneys rather, a portion is removed
  during each sweep of the blood through the renal
  system. Clearance may be defined as the volume of
  plasma which is completely cleared of a solute in
  a unit of time and is usually expressed in
  ml/min. Stated another way, the renal clearance
  of a substance represents the volume of blood
  that would have to pass through the nephrons
  within a given time period to provide the amount
  of that substance in the urine. Substances which
  are rapidly eliminated have a high clearance
  those eliminated slowly, a low clearance.

Glomerular Filtration The glomerulus acts as an
ultrafilter, allowing passage of water,
electrolytes, and small organic molecules such as
glucose, but not blood cells and large protein
molecules. The ultrafiltrate produced by the
glomeruli of both kidneys amounts to about 70
ml/min/sq m or 150 L/day/sq m this rate is
termed the glomerular filtration rate (GFR).
About 99 of the glomerular filtrate is resorbed
during passage through the renal tubules, with
most of the resorption taking place in the
proximal tubules.
7
Radiological examination of the urinary tract

• The four basic examinations of the urinary tract
  are intravenous urography (IVU), computed
  tomography (CT), ultrasound and radionuclide
  examinations. Magnetic resonance imaging (MRI),
  arteriography and studies requiring
  catheterization or direct puncture of the
  collecting systems are limited to highly selected
  patients.
• The IVU provides both functional and anatomical
  information. CT, MRI and ultrasound are
  essentially used for anatomical information the
  functional information they provide is limited.
  The converse is true of radionuclide examinations
  where functional information is paramount.
• Ultrasound is the first-line investigation to
  demonstrate or exclude hydronephrosis,
  particularly in patients with renal failure, and
  to diagnose renal tumours, cysts and abscesses.
• Computed tomography is preeminent for staging
  renal tumours, for diagnosing or excluding trauma
  to the urinary tract and for showing pathology in
  the retroperitoneum.

8
Radiographic Evaluation of the Urinary System

• A plain x-ray of the abdomen (kidney, ureter,
  bladder KUB) is performed first to demonstrate
  the size and location of the kidneys. Since
  gastrointestinal and urinary system diseases tend
  to mimic each other, the x-ray may be helpful in
  differential diagnosis However, the renal outline
  can be obscured by bowel content, lack of
  perinephric fat, or a perinephric hematoma or
  abscess. This difficulty may be overcome by
  tomography. Congenital absence of a kidney may be
  suggested. If both kidneys are unusually large,
  polycystic kidney disease, multiple myeloma,
  lymphoma, amyloid disease, or hydronephrosis may
  be present If both are small, the end stage of
  glomerulonephritis or bilateral atrophic
  pyelonephritis must be considered. Unilateral
  enlargement should suggest renal tumor, cyst, or
  hydronephrosis, whereas a small kidney on one
  side is compatible with congenital hypoplasia,
  atrophic pyelonephritis, or an ischemic kidney
  Normally, the left kidney is 0.5 cm longer than
  its mate.
• In 90 of cases, the right kidney is lower than
  the left because of displacement by the liver.
  The long axes of the kidneys are oblique to the
  spine and tend to parallel the borders of the
  psoas muscles. If both kidneys are parallel to
  the spine, the possibility of horseshoe kidneys
  should be considered. If only one kidney is
  displaced, a tumor or cyst should be considered
  Because an x-ray film is two-dimensional, a
  positive diagnosis of a stone in the urinary
  tract is practically impossible except in the
  instance of a staghorn calculus. However,
  suspicious opaque bodies may be noted in the
  region of the adrenal, kidney, ureter, bladder,
  or prostate. Oblique and lateral films, as well
  as visualization of the urinary tract with
  radiopaque fluids, are necessary in order to
  place the calcification specifically within these
  organs.

9
An excretory urogram is used to visualize the
kidney and lower urinary tract. Studies are done
by an IV infusion of a triiodinated benzoic acid
derivative. The iodine molecule provides
radiopacity, while the benzoic acid molecule is
rapidly filtered by the kidney. After IV
injection of a contrast agent, the drug becomes
concentrated in the renal tubules within the
first 5 min, providing a nephrogram. Later, the
contrast agent appears in the collecting system,
outlining the renal pelvis, the ureters, and
finally the bladder. This ability to visualize
the urinary system is dependent on adequate renal
function and, to some degree, on the absence of
an osmotic or water diuresis which would dilute
the contrast agent. Therefore, the best
radiograms are obtained in patients with a normal
GFR who have been water-restricted. It is usually
difficult to obtain an adequate study in patients
with a BUN gt 70 mg/dl or a plasma creatinine gt 7
mg/dl. Excretory urograms are indicated when
disease of the urinary tract is suspected. This
test may be useful in investigating cysts and
tumors of the kidneys (space-occupying lesions),
infections of the kidney (distortion of the
calyces), hydronephrosis, vesicoureteral reflux,
hypertension, and Iithiasis. If renal injury is
suspected, excretory urography should be done to
make certain that the contralateral uninjured
kidney is normal, and to obtain functional
information about the injured kidney. Finally,
excretory urograms are indispensable in infants,
particularly males, for whom cystoscopy may be
unduly traumatic.
10

• The retrograde pyelogram is a procedure in which
  radiopaque agents similar to those used in
  excretory urography are introduced directly into
  the urinary tract following cystoscopy and
  catheterization of the ureter. The technic
  provides more intense opacification of the
  collecting and voiding system when the excretory
  urogram has been unsuccessful owing to poor renal
  function. Retrograde evaluation may also be
  indicated to assess the degree of ureteral
  obstruction or when the patient is allergic to IV
  radiopaque chemicals.
• The cystogram is obtained as a part of the
  excretory urogram but may be unsatisfactory owing
  to poor opacification or incomplete filling.
  Controlled bladder filling utilizing a catheter
  (retrograde cystogram) is then necessary for
  adequate visualization. Retrograde cystograms
  are advisable for study of neurogenic bladder,
  bladder rupture, or recurrent urinary tract
  infections. Such causes as vesicoureteral reflux
  or vesical fistulas are best diagnosed by this
  technic.
• The male urethra may be examined by the
  retrograde injection of a contrast agent,
  although the information needed is frequently
  seen in a voiding film after an excretory
  urogram. When the retrograde urethral injection
  is combined with this cystography, the combined
  procedure is called retrograde urethrocystography.
  
• For special problems concerning the integrity of
  the renal blood supply, contrast media may be
  selectively injected into the arterial supply
  (arteriography) or the venous system (venography).

11
Renal Evaluation with Radioisotopes

• Radionuclides which are selectively accumulated
  or secreted by the kidney permit evaluation of
  renal structure and function without introducing
  the hypertonic and chemical stress of IV
  contrast agents. Because of the trace amounts
  given, the danger of hypersensitivity is
  decreased and, with the use of rapidly decaying
  isotopes, the biologic damage from radiation is
  small The particular advantage of radioisotopic
  scintiphotography over x-rays is the ease with
  which radioisotope concentration can be estimated
  by counting radioactive disintegrations while a
  simultaneous image of radioisotope dilution is
  produced Thus, static as well as dynamic studies
  are possible While x-ray images are not readily
  susceptible to numerical quantitation, they do
  have a higher resolution than radioisotope
  images.
• All of the radiopharmaceuticals currently used
  for renal evaluation are labeled with ?-emitting
  radionuclides ? -Radiation penetrates tissue as
  do x-rays and is detected by the ?-camera Current
  technology allows a continuous dynamic
  observation of the radioactivity accumulating in
  the urinary system Accumulation in the kidney of
  any of these chemicals is dependent initially
  upon renal blood flow, which is sufficiently
  large that the kidneys are seen as well-defined
  images with relatively little labeling of
  surrounding structures Thus, isotopic studies can
  be used to determine vascularity in any renal
  mass lesion A "cold" area with little
  radioactivity suggests a lack of vascularity and,
  if spherical, a cyst An area of high vascularity
  suggests a vascular tumor, usually a neoplasm
  Vascular tumors often demonstrate greatest
  uptake of radioactivity at a time which differs
  from that of the uninvolved renal cortex In the
  presence of neoplastic disease, the surrounding
  renal cortex may show reduced blood flow due to
  the local pressure of the tumor or to invasion of
  vascular structures Simple cysts tend to cause
  discrete spherical defects without other
  disturbance of renal cortical blood flow.

12
Renal Evaluation with Radioisotopes

• Scintiphotography also provides an opportunity
  to determine the presence of regional renal
  ischemia causing renal vascular hypertension The
  site of regional renal ischemia often may be
  defined, rather than just comparing one entire
  kidney to the other Scintiphotography is also an
  excellent tool for evaluating the success of
  vascular and ureteral anastomoses in the period
  immediately following transplantation In
  evaluation of renal trauma, radioisotopic studies
  are useful in the diagnosis of extrarenal
  hematoma, renal lacerations, reduction of renal
  function secondary to contusion, or urine
  extravasation Lastly, radioisotopes may be useful
  in obstructive uropathy and may give sufficient
  structural delineation to obviate the need for
  retrograde urography.

13
Ultrasound Evaluation of the Urinary System

• Ultrasonic technics are increasingly being used
  to evaluate urinary system disease Much of the
  information obtained is purely anatomic, but the
  technic has the advantage that visualization does
  not depend on function Nevertheless, some
  functional information can be inferred,
  especially in the fetus, in whom the kidneys can
  be identified with certainty after about 20 wk
  gestation, permitting measurement of urine
  production rate by serial estimations of the
  bladder volume Fetal hydronephrosis, polycystic
  kidney, and bladder neck obstruction have also
  been detected In the neonatal period, ultrasound
  should be the first-choice technic for
  investigating abdominal masses, for the results
  may be 95 to 98 accurate
• Ultrasound is extremely accurate in
  differentiating solid from cystic masses in
  patients of all ages Since ultrasound
  examinations are innocuous, they are also useful
  for the follow-up of known lesions, either
  without treatmentsuch as cysts incidentally
  detectedor after treatment for hydronephrosis or
  calculus This is especially the case in younger
  patients, in whom repeated radiographic
  examination is best avoided In transplanted
  kidneys, ultrasound has been used to detect and
  follow the progression of perinephric fluid
  collections Recent developments in ultrasound
  suggest the possibility of estimating blood flow
  in the kidney.

14
Renal Biopsy

• There are four reasons for performing renal
  biopsies (1) to help establish a histologic
  diagnosis (2) to help estimate prognosis and the
  potential reversibility or progression of the
  renal lesion (3) to estimate the value of
  therapeutic modalities and (4) to determine the
  natural history of renal diseases. The only
  absolute contraindication to a biopsy is an
  uncontrollable bleeding disorder. The biopsy of a
  solitary kidney is a relative contraindication to
  be weighed against the need for information.
  Biopsies of a single, functioning, transplanted
  kidney are done frequently to diagnose and study
  possible graft rejections. Conditions associated
  with an increased morbidity following biopsy are
  deemed relative contraindications these include
  renal tumors, large renal cysts, hydronephrosis,
  perinephric abscesses, severe reduction in blood
  or plasma volume, severe hypertension, and
  advanced renal failure with symptoms of uremia.
• There are two biopsy technics, open and
  percutaneous the percutaneous tech-nic is most
  common. The open surgical method is rarely
  necessaryonly when the percutaneous method has
  been unsuccessful or when direct visual control
  of the biopsy is deemed critical. For the
  percutaneous technic the patient is sedated, and
  the kidney is visualized by radiographic or
  ultrasonic technics. With the patient in the
  prone position and following local anesthesia of
  the overlying skin and muscles of the back, the
  biopsy needle is inserted and tissue is obtained
  for light, electron, and immunofluorescent
  microscopy.

15
Oblique views to determine whether calcifications
are intra- or extrarenal. (a) A rounded
calcification is seen overlying the left kidney
in the AP plain film, (b) In the oblique plain
film, the calcification is in the same position
within the renal shadow and is, therefore, a
renal calculus, (c) A rounded calcification is
seen over the right renal shadow, (d) An oblique
film after contrast shows that the calcification
lies outside the kidney. It was later confirmed
to be a gall stone
16
Normal IVU. Full length 15min film. Note that the
bladder is well opacified. The whole of the right
ureter and part of the left ureter are seen.
Often, only a portion of the ureter is visualized
owing to peristalsis emptying certain sections.
The bladder outline is reasonably smooth. The
roof of the bladder shows a shallow indentation
from the uterus.
17
Large calcified calculus in the pelvis of the
kidney obscured by contrast medium. Since the
contrast medium and the calculus have the same
radiographic density, the calculus is hidden by
the contrast medium.
18
Renal mass. A renal cyst (arrows) has caused a
bulge on the lateral aspect of the kidney with
splaying of the calices.
19
The calices. (a) Normal calices. Each calix is
'cup-shaped', (b) Many of the calices are
clubbed. There is scarring of the parenchyma of
the upper half of the kidney indicating that the
diagnosis is chronic pyelonephritis, (c) All the
calices are dilated, the dilatation of the
collecting system extending down to the point of
obstruction (arrow), in this case owing to a
malignant retroperitoneal lymph node
20
At ultrasound, the kidneys should be smooth in
outline. The parenchyma surrounds a central
echodense region, known as the central echo
complex (also called the renal sinus), consisting
of the pelvicaliceal system, together with
surrounding fat and renal blood vessels. In most
instances, the normal pelvicaliceal system is not
separately visualized. The renal cortex generates
homogeneous echoes which are less intense than
those of the adjacent liver or spleen and the
renal pyramids are seen as triangular sonolucent
areas adjacent to the renal sinus. During the
first two months of life, cortical echoes are
relatively more prominent and the renal pyramids
are strikingly sonolucent.
Normal renal ultrasound
The normal adult renal length, measured by
ultrasound, is 9-12cm. These figures are lower
than those for renal size measured by IVU,
because there is no swelling from the action of
contrast medium and there is no magnification of
the image.Normal ureters are not usually
visualized. The urinary bladder should be
examined in the distended state the walls should
be sharply defined and barely perceptible.
21
CT and MRIComputed tomography is used for
specific indications, often after IVU or
ultrasound have identified a problem.Like
ultrasound, CT can characterize masses and it
showsthe retroperitoneal space. It is an
extremely sensitive method of detecting calculi
andI is also useful when assessing trauma or
infarction. The technique is virtually the same
as for standard abdominal and pelvic CT, except
that sections of the kidneys are usually
performed both before and after intravenous
contrast medium has been given.Magnetic
resonance imaging gives similar information to
CT, with a few specific advantages, but it has
several disadvantages and is only used in
selected circumstances, e.g. demonstrating renal
artery stenosis and inferior vena caval extension
of renal tumours.
22
Normal CT The basic principles of interpretation
are the same as for IVU. The renal parenchyma
should have a smooth outline and opacify
uniformly after intravenous contrast
administration, although early images may show
opacification of the cortex before medullary
opacification has had time to occur. The
pelvicaliceal system should show cupped calices
with uniform width of renal parenchyma from calix
to renal edge, and the fat that surrounds the
pelvicaliceal system should be clearly
visualized. The ureters are seen in cross-section
as dots lying on the psoas muscles. They will not
necessarily be seen at all levels because
peristalsis obliterates the lumen intermittently.
The bladder has a smooth outline contrasted
against the pelvic fat its wall is thin and of
reasonably uniform diameter. Contrast
opacification of the urine in the bladder is
variable depending on how much contrast has
reached the bladder. The contrast medium is
heavier than urine and therefore, the dependent
portion is usually more densely opacified.
23
Normal CT of kidneys and bladder, (a), (b)
Adjacent sections, (b) 1 cm higher than (a),
showing uniform opacification of parenchyma with
well-defined cortical edge. The pelvicaliceal
system, which is densely opacified, is surrounded
by fat. The renal veins are well shown on the
higher section, (c) (not present) Section through
the level of the ureters (arrows) after contrast
has been given, (d) Section through opacified
bladder in a male patient shows that the bladder
wall is too thin to be seen. Note the layering of
contrast medium, (e) Section through bladder
without contrast opacification. The bladder wall
can be identified as a thin line. A, aorta I,
inferior vena cava K, kidney P, pelvis RV,
renal vein Sp, spine.
24
Radionuclide examination

• There are two main radionuclide techniques for
  studying the kidneys
• The renogram which measures renal function. Scans
  of renal morphology (DMSA scan). The advent of CT
  and ultrasound has reduced the need for such
  scans. They are now used mainly for evaluating
  renal scanning.

25
Renogram

• If substances which pass into the urine are
  labelled with a radionuclide and injected
  intravenously, their passage through the kidney
  can be observed with a gamma camera.
• The two agents of choice are "?? DTPA
  (diethylene triamine pentacetic acid) and mjc
  MAG-3 (mercaptoacetyl triglycine). DTPA is
  filtered by the glomeruli and not absorbed or
  secreted by the tubules, whereas MAG-3 is both
  filtered by the glomeruli and secreted by the
  tubules.
• The gamma camera is positioned posteriorly over
  the kidneys and a rapid injection of the
  radiopharmaceutical is given. Early images show
  the major blood vessels and both kidneys.
  Subsequently, activity is seen in the renal
  parenchyma and by 5min the collecting systems
  should be visible. Serial images over 20min show
  progressive excretion and clearance of activity
  from the kidneys. Quantitative assessment with a
  computer enables a renogram curve to be produced
  and the relative function of each kidney
  calculated. The main indications for a renogram
  are
• measurement of relative renal function in each
  kidney -this may help the surgeon decide between
  nephrectomy ormore conservative surgery
• investigation of urinary tract obstruction,
  particularlypelviureteric junction obstruction
• investigation of renal transplants

26
The renogram curve. a)Vascular phase. b)
Filtration phase, (c) Excretion phase, (d)
27
Retrograde and antegrade pyelographyThe
techniques of retrograde and antegrade
pyelography (the term pyelography means
demonstrating the pelvical-iceal system and
ureters) involve direct injection of contrast
material into the pelvicaliceal system or ureters
through catheters placed via cystoscopy
(retrograde pyelography) or percutaneously into
the kidney via the loin (antegrade pyelography).
The indications are limited to those situations
where the information cannot be achieved by less
invasive means, for example in those few cases of
hydronephrosis where further information about
the level and nature of obstruction is required.
28
Plain film showing a calcified staghorn calculus
in each kidney.
29
Ultrasound of stone in right kidney. The stone
(arrow) appears as a bright echo. Note the
acoustic shadow behind the stone (double headed
arrow).
30
Nephrocalcinosis. There are numerous
calcifications in the pyramids of both kidneys
(the left kidney is not illustrated).
Ureteric obstruction. The pelvicaliceal system
and ureter are dilated down to the level of the
obstructing pathology (arrow), in this instance a
small calculus
31
Acute ureteric obstruction from a stone in the
lower end of the left ureter, (a) A film taken 30
min after the injection of contrast medium. There
is obvious delay in the appearance of the
pyelogram on the left. The left kidney shows a
very dense nephrogram which is characteristic of
acute ureteric obstruction, (b) A film taken 23 h
later shows opacification of the obstructed
collecting system down to the obstructing
calculus (arrow).
32
Dilatation of the pelvicaliceal system, (a)
Longitudinal ultrasound scan of right kidney
showing spreading of the central echo complex of
the dilated collecting system (arrows), (b) Here
the dilatation of the calices is greater
(arrows), (c) In this image from a patient with
pelviureteric obstruction, the dilated calices
resemble cysts, (d) CT scan after contrast
showing a dilated renal pelvis (asterisk). The
vertical arrow points to a small amount of
contrast pooling in a dependent calix. Note the
normal left ureter (horizontal arrow).
33
Renal pseudotumour (arrows) which was
subsequently shown to be normal renal cortical
tissue.
34
Ultrasound in renal masses, (a) Cyst (C) showing
sharp walls and no echoes arising within the
cyst. Note the acoustic enhancement behind the
cyst, (b) Tumour showing echoes within a solid
mass (M). (c) Complex mass due to cystic renal
cell carcinoma. The arrows point to the edge of
the mass. Note the thick septa within the mass,
(d) Angiomyolipoma. This incidental finding shows
the typical appearance of a small echogenic mass
(arrow).
35
Computed tomography (contrast-enhanced) in renal
masses, (a) Cyst in left kidney (C) showing a
well-defined edge, imperceptible wall and uniform
water density. The cyst shows no enhancement. It
was an incidental finding, (b) Renal cell
carcinoma. The mass (arrows) is not clearly
demarcated from the adjacent kidney and shows
substantial enhancement. (c) Angiomyolipoma with
a small mass (arrow) of fat density.
36
Staging renal carcinoma, (a) CT scan showing a
large mass (M) in the left kidney from renal cell
carcinoma and a greatly enlarged lymph node
(arrows) in the left paraaortic area. This node
contained metastatic tumour cells, (b) Coronal
MRI scan showing a huge left renal carcinoma (M)
with tumour extending into the inferior vena cava
(IVC) via the left renal vein. The caval
extension of tumour () extends to the top of the
IVC. (c) Axial MRI scan showing the IVC extension
of tumour (arrows). Normally, the IVC is seen as
a signal void.
37
Renal abscess, (a) Ultrasound scan showing a
complex mass (arrows) in the right kidney, (b) CT
scan in a different patient showing encapsulated
fluid collection in the lower pole of the right
kidney (arrows). D, diaphragm L, liver LK, left
kidney RK, right kidney Sp, spleen.
38
Perinephric abscess. CT scan showing a rounded
loculation of fluid and gas in the left
perinephric space (arrows).
39
Renal trauma, (a) The lower pole of the kidney
has been ruptured and a pool of extravasated
contrast can be seen, (b) CT scan showing
extensive haematoma (arrows) surrounding a
fragmented left kidney (K)
40
Horseshoe kidneys, (a) The two kidneys are fused
at their lower poles. The striking feature is the
alteration in the axis of the kidneys the lower
calices are closer to the spine than the upper
calices. The kidneys are rotated so that their
pelves point forward and the lower calices point
medially. The medial aspects of the lower poles
cannot be identified, (b) CT scan of different
patient, following i.v. contrast enhancement,
showing fusion of the lower poles of the kidneys.
K, kidney.
41
Bladder neoplasm, (a) There is a large filling
defect in the left side of the bladder from a
transitional cell carcinoma. Note the obstructive
dilatation of the left ureter, (b) Ultrasound
scan from a different patient showing a large
tumour (T) within the bladder.
42
CT scan of carcinoma of bladder, showing an
extensive tumour (T) involving the bladder wall
but still confined to the bladder.
43
Bladder diverticula. Cystogram showing numerous
outpouchings from the bladder with a very large
diverticulum projecting to the left.
44
Prostatic enlargement. The bladder base is lifted
up and shows an impression from the enlarged
prostate (arrows). The ureters are tortuous and
enter the bladder horizontally. A balloon
catheter is in the bladder.
45
Prostate carcinoma shown by transrectal
ultrasound. T, tumour.
Carcinoma of the prostate. CT scan showing
massively enlarged prostate (P) indenting the
bladder. The tumour has spread to involve pelvic
lymph nodes. A huge lymph node mass is seen (L).
B, bladder C, colon.
46
Prostate carcinoma (T) invading lower part of
bladder, shown on MRI scan (T1-weighted sagittal
section).

47
Prostatic calcification. Numerous calculi just
above the pubic symphysis are present in the
prostate.
48
Urethral stricture. An ascending urethrogram
showing a stricture in the penile urethra
(arrow). The patient had gonorrhoea.
49
MRI of seminoma (arrow) in right testis. The two
testes are well demonstrated. The high signal
adjacent to both testes is normal fluid between
the layers of the tunica vaginalis.
50
Normal uterus and vagina. Longitudinal section.
The central echo of uterus (U) corresponds to the
endometrial cavity the uterus itself has a
homogeneous echo texture V, vagina B, bladder.
51
Normal ovaries (arrows). Transverse section in
25-year-old woman. B, bladder.
Normal uterus, CT scan. B, bladder U, uterus.
52
Normal uterus, sagittal T2-weighted MRI scan.
There is a high signal from the endometrium
(arrows). B, bladder V, vagina.
53
Ovarian cyst, (a) Longitudinal ultrasound scan to
right of midline showing a 5 cm cyst (C) in right
ovary with no internal echoes. B, bladder, (b) CT
scan of same patient showing the cyst in the
right ovary (arrows). Note the uniform water
density centre of the cyst, (c) Coronal
T2-weighted MRI scan showing a left sided ovarian
cyst (arrows) in a patient with an enlarged
uterus due to adenomyosis. B, bladder U, uterus.
54
Ovarian carcinoma, (a) Longitudinal ultrasound
scan showing a very large multilocular cystic
tumour containing septa (S) and solid nodules
(N). The lesion was a cystadenocarcinoma. (b) CT
scan showing large partly cystic, partly solid
ovarian carcinoma (arrows). The tumour, which
contains irregular areas of calcification, has
invaded the right side of the bladder (B). The
rectum is indicated by a curved arrow, (c) MRI
scan showing a partly solid (arrows) and partly
cystic tumour. The cystic component shows as a
high signal on this T2-weighted scan. B, bladder.