The document provides information on the anatomy, normal variants, and ultrasound imaging of the kidney, ureter, urinary bladder, and prostate. It describes the location, structure, blood supply, and size of the kidney. It discusses variants such as horseshoe kidney and renal cysts/masses. Hydronephrosis and its grading are also covered. The anatomy and constriction points of the ureter are summarized. Indications for ultrasound of the bladder include hematuria and infection. Normal and abnormal bladder findings like thickening, tumors, and calculi are outlined. Lastly, the zonal anatomy, blood supply, and common pathology of the prostate are briefly described to introduce transrectal ultrasound examination.

1. SEMINAR TOPIC
ANATOMY,NORMAL VARIANTS AND USG
IMAGING OF
KIDNEY
URETER
URINARY BLADDER
PROSTATE

2. ANATOMY OF KIDNEY
KIDNEYS
• The kidneys are paired retroperitoneal organs that lie at
the level of the T12 to L3 vertebral bodies.
LOCATION
The kidneys are located on the posterior abdominal wall, with
one on either side of the vertebral column, in the perirenal
space. The long axis of the kidney is parallel to the lateral
border of the psoas muscle and lies on the quadratus
lumborum muscle. The kidney lie at an oblique angle,the
superior renal pole is more medial and posteriorly than the
inferior pole.

4. SIZE
• In adults a difference of more than 2 cm in length is abnormal.
1.Length : up to10-14 cm in males and 9-13 cm in females
2 . Width: normally 4-6 cm but may vary a little with the angle of
the scan
3. Thickness: up to 3.5 cm but may vary a little with the angle of
the scan
4. The central echo complex (the renal sinus) is very echogenic
and normally occupies about one-third ofthe kidney . (The renal
sinus includes the pelvis. calyces. vessels and fat.)
5. In the newborn. the kidneys are about 4 cm long and 2 cm
wide . The renal pyramids are poorly defined hypoechogenic
areas in the medulla of the kidney. surrounded by the more
echogenic renal cortex. It is easier to see the pyramids in children
and young adults.
6.weight- 150-260 g.

5. Structure of kidney
• The kidney is bean-shaped with a superior and an inferior pole,anterior and
posterior surfaces, and lateral and medial borders. The midportion of the kidney is
often called the midpole.
• The kidney has a fibrous capsule, which is surrounded by perirenal fat. The kidney
itself can be divided into renal parenchyma, consisting of renal cortex and
medulla, and the renal sinus containing renal pelvis, calyces, renal vessels, nerves,
lymphatics and perirenal fat.
• The renal parenchyma has two layers: cortex and medulla. The renal cortex lies
peripherally under the capsule while the renal medulla consists of 10-14
renal pyramids, which are separated from each other by an inward extension of
the renal cortex called renal columns.
• The renal hilum is the entry to the renal sinus and lies vertically at the
anteromedial aspect of kidney.It contains renal vessels,nerves,fat.

7. FUNCTIONS
• Filter the blood to remove excess water,minerals
and waste products of protein metabolism
producing urine.
• Blood pressure regulation.
• Regulation of body fluid volume,osmolality and
ph.
• Vitamin D and red blood cell production.
• Tests of renal function-estimated glomerular
filtration rate(eGFR),electrolytes,blood urea
nitrogen(BUN),creatinine levels and creatinine
clearance,cystation c levels.

8. BLOOD SUPPLY
Arterial supply
• Renal arteries originate from abdominal aorta
and enter the renal hila to supply the kidneys.
Venous drainage
• The renal veins are asymmetric paired
retroperitoneal veins that drain the kidneys into
Inferior vena cava at L2.

9. BLOOD SUPPLY OF KIDNEY

10. Normal Adult Kidney Appearance
In USG
• cortex is less echogenic than the liver
• medullary pyramids are slightly less echogenic than the
cortex
• cortex thickness equals/is more than 6 mm
• central renal sinus, consisting of the calyces, renal
pelvis and fat, is more echogenic than the cortex
• renal pelvis may appear as a central slit of anechoic fluid at
the hilum
• normal ureters are generally not well seen on ultrasound.

11. USG IMAGE OF NORMAL KIDNEY

12. Variants of kidney
• number
– renal agenesis
– supernumerary kidney
• fusion
– horseshoe kidney; most common
– cross fused renal ectopia
– pancake kidney
– supernumerary kidney
• location
– pelvic kidney
– crossed renal ectopia (fused or unfused)
– abnormal renal rotation (renal malrotation)
– Nephroptosis (floating kidney)
– intrathoracic kidney
• shape
– persistent fetal lobulation
– hypertrophied column of Bertin
– hilar lip
– dromedary hump

13. Ultrasonography Indications of kidney
1. Renal or ureteric pain.
2. Suspected renal mass (large kidney).
3. Non-functioning kidney on urography.
4. Haematuria.
5. Recurrent urinary infection.
6. Trauma.
7. Suspected polycystic disease.
8. Pyrexia of unknown origin or postoperative
complication.
9. Renal failure of unknown origin.
10. Schistosomiasis.

14. Absent Kidney
• If either kidney cannot be seen. search again.
• If one kidney cannot be demonstrated. consider the
following possibilities:
• 1. The kidney may have been removed. Check the clinical
history and examine the patient for scars.
• 2. The kidney may be ectopic.
• 3. If only one large but normal kidney is demonstrated and
there has not been any surgery. it is likely that there is
congenital absence of the other kidney.
• 4. Apparent absence of both kidneys may be a failure to
demonstrate them with ultrasound because of changed
echogenicity resulting from chronic disease of the renal
parenchyma.

15. Large Kidney
Bilateral enlargement
1. When the kidneys are enlarged but normal in shape, with normal,decreased or
increased homogeneous echogenicity. the possible causes are:
• Acute or subacuteglomerulonephritis or severe pyelonephritis
• Amyloidosis (probably increased echogenicity).
• The nephrotic syndrome.
2. When the kidneys have a smooth outline and are unifonnly enlarged.
with non-homogeneous hyperechogenicity. the possible causes are:
• Lymphoma. This may cause multiple areas oflow density, especially
Burkitt lymphoma in children or young adults .
• Metastases .
• Polycystic kidneys
Unilateral enlargement
If one kidney appears to be enlarged but has nonnal echogenicity, and
the other kidney is small or absent, the enlargement may be due to
compensatory hypertrophy.

16. One kidney is enlarged or more
lobulated than normal
• Common cause of enlarged kidney is hydronephrosis.
• IN USG appear as multiple well circumscribed cystic areas with
a dilated central cystic area(renal pelvis normally less than 1 cm
in width.
• Hydronephrosis caused by congenital obstruction of the
ureteropelvic junction by ureteric stenosis.
• HYDRONEPHROSIS-To assess the degree of hydronephrosis
measure the size of pelvis when the bladder is empty.
1. MILD-If pelvis is wider than 1cm and there is nocalyceal
dilation.
2. Moderate-There is calyceal dilation.
3. Severe-There is loss of renal cortex.

17. TYPES OF HYDRONEPHROSIS

18. Renal Cyst
• In ultrasound shows multiple, echo-free, well
circumscribed areas throughout the kidney.
• 1. Simple cysts can be single or multiple. On
ultrasound the walls are smooth and rounded without
internal echoes, but with a clearly defined back wall.
More than 70% of all renal cysts are due to benign
cystic disease. These cysts are very common over the
age of 50 years and maybe bilateral.
• 2. Hydatid cysts usually contain debris and
• are often loculated or septate.When calcified, the wall
appears as a bright,echogenic convex line with acoustic
shadowing.

19. SIMPLE CYST IN RIGHT KIDNEY

20. Renal Mass
• Solid renal mass-Renal masses may be well
circumscribed or irregular and may alter the
shape of the kidney. Echogenicity may be
increased or decreased.
• A complex non-homogeneous mass.
• IN children,malignant tumours, e.g.
nephroblastoma(Wilms tumour), may be well
encapsulated but not homogenous.

21. IMAGE OF RENAL MASS

22. Small Kidney
1. A small kidney with normal echogenicity may be
due to renal artery stenosis or occlusion, or to
congenital hypoplasia.
2. A small kidney, normal in shape but
hyperechogenic, may indicate chronic renal disease.
3. A small, hyperechogenic kidney with an
irregular,rough outline and variable thickness of the
cortex (usually bilateral but often very asymmetrical)
is probably the result of chronic pyelonephritis or
infection such as tuberculosis.

23. Renal Calculi
• A calculus will be hyperechogenic with an
acoustic shadow . The calculus must be
visualized in two different planes, longitudinal
and transverse, to permit accurate localization
and measurement.
• Trauma
• Perirenal fluid
• Retroperitoneal mass

24. USG IMAGE OF RENAL STONE

25. Ureter
• The ureter is a paired fibromuscular tube that
conveys urine from the kidneys in the abdomen
to the bladder in the pelvis.
ANATOMY
• The ureter is 25-30 cm long and has three parts
1. Abdominal ureter-from renal pelvis to the pelvic
brim.
2. Pelvic ureter-from pelvic brim to the bladder.
3. Intravesical or Intramural ureter-within in the
bladder wall.

26. CONSTRICTIONS
• The ureter has a diameter of 3 mm.
• Three constrictions sites-most common sites of
renal calculus obstruction:
1. Pelviureteric junction(PUJ) of the renal pelvis
and ureter.
2. As the ureter enters the pelvis and crosses over
the common iliac artery bifurcation.
3. At the vesicouretric junction(VUJ) as the ureter
obliquely enters the bladder wall.

27. CONSTRICTIONS OF URETER

28. BLOOD SUPPLY
• Arterial supply-branches of renal
artery,abdominal aorta,superior amd inferior
vesical arteries.
VARIANT OF URETER
• Duplex collecting system.
• Bifid ureter
• Ectopic ureter
• ureterocele

29. Usg imaging of ureter
• Not easy to examine normal ureters by USG.
• If dilated(e.g. by outlet obstruction due to
enlarged prostate or uretheral stricture or due to
vesico ureteric reflux) are easier to see.
• Lower end of ureters can be observed by scanning
through a full bladder which provides a useful
acoustic window.

30. URINARY BLADDER
• ANATOMY
• The bladder is an extraperitoneal structure located
in true pelvis.Function as a reservoir for urine.
• The bladder has a triangular shape with a posterior
base,an inferior neck with two inferolateral
surfaces.
• The trigone is a triangular area of smooth mucosa
on the internal surface of base.
• The urethera arises from neck of
bladder,surrounded by the internal uretheral
sphincter.

31. BLOOD SUPPLY OF BLADDER
Arterial
• Upper part in both males and females by superior
vesical artery branch of anterior division of internal
iliac artery.
• Lower part in males by inferior vesical artery and in
females by vaginal artery branch of anterior
division of internal iliac artery.
VARIANT ANATOMY
• Double bladder-receives ipsilateral ureter and has
seprate urethera.

33. VARIANT ANATOMY cont.
• Septation
• Agenesis
• Ureterocele-dilation of the intravesical part of the
ureter.
USG INDICATIONS OF URINARY BLADDER
1. Dysuria or frequency of micturation
2. Haematuria
3. Recurrent infection(cystitis)
4. Pelvis mass
5. Retention of urine
6. Pelvic pain

34. Prepration of patient
• The bladder must be full.Give 4-5 glass of water
and examine after one hour.
• The patient should be supine.
• Start with transverse scan from the pubic
symphysis upwards to the umbilicus followed by
longitudinal scans moving from one side of the
lower abdomen to the other.
• Full bladder appear as large ,echo free area arising
out of the pelvis.
• Distended normal bladder wall is less than 4 mm
thick.

35. ABNORMAL BLADDER
• GENERALIZED THICKENING OF BLADDER WALL
1. In men bladder wall thickening due to prostatic
obstruction.
2. Severe chronic infection/cystitis-inner wall thickened
and irregular.
3. Schistosomiasis-bladder walls may be thickened with
increased echogenicity and scattered dense(bright)
areas due to calcification.
4. Very thick trabeculated bladder walls in children
result from outlet obstruction caused by uretheral
valves or urogenital diaphragm.
5. Neurogenic bladder.

36. ABNORMAL BLADDER CONT.
LOCALIZED THICKENING OF BLADDER WALL
• Bladder fold due to incomplete filling.
• Tumour
• Localized infection due to tuberculosis or
schistosomal plaques.
• Acute reaction to schistomal infection.
• Haemotoma following trauma.
DENSITY WITHIN BLADDER
1. Attached to the wall
• Polyp-appear freely mobile on a long stalk.
• Adherent calculus

37. HAEMATOMA IN BLADDER

38. POLYP IN BLADDER

39. DENSITY WITH IN BLADDER CONT.
• Ureterocele-cystic mass within the bladder near a
ureteric orifice.In children ureterocele may be so
large that the opposite ureter is also obstructd.
• Enlarged prostate
2. MOBILE DENSITY WITHIN BLADDER
• Calculus
• Foreign body
• Blood clot
• Air

40. URETEROCELE IN BLADDER

41. CALCULUS IN BLADDER

42. LARGE(OVERDISTENDED)BLADDER
• Common causes
1. Enlargement of prostate
2. Uretheral stricture in male
3. Urethal calculus in male
4. Bruising of the urethera I female(honeymone
urethritis)
5. Neurogenic bladder
6. Uretheral valves
• SMALL BLADDER
1. Recurrent cystitis
2. Radiotherpy or surgery for malignancy

43. PROSTATE
• The prostate gland is part of the male reproductive
system and is the largest male accessory gland.
• Weight - 20-40 grams.
• Average size-3x4x2cm.
• Consists of 70% glandular tissue and 30% fibromuslar
or stromal tissue.
• The prostate gland is an inverted pyramid that
surround the proximal urethera which traverses the
prostate close to its anterior surface at base and then
more centrally.
• Best assessed with transrectal USG.Outer gland(central
and peripheral zones) uniform low echogenicity but
more echogenic than the inner gland.30 ml is upper
limit for normal volume.

45. ZONAL ANATOMY
• Three distinct zones-
1. Peripheral zone-
• Large cup shaped
• Encompasses central and transition zones and
account for approximately 70% of total prostate
volume in adult.
• It surrounds distal prostatic urethera at apex of
prostate and extends posterolaterally to the base.
• Deficient anteriorly where it is replaced by anterior
fibromuscular stroma(AFMS).
• Majority(70%) of prostatic tumour occur in this
zone.

46. ZONAL ANATOMY cont.
2. CENTRAL ZONE-
• Small wedge shaped.
• Constitutes 25% of the prostate volume and
contains ejaculatory ducts.
• It is posterior to the prostatic urethra and forms the
base of the prostate.
3.TRANSITION ZONE-
• Smaller,Benign prostatic hypertrophy occurs in this
zone,20% prostatic cancers occur in this zone.
• Comprises of 5% of prostatic volume.
• It is predominantly anterolateral to the prostatic
urethra.

48. BLOOD SUPPLY
1. Arterial supply-
• Prostatic branch og inferior vesical artery branch
of anterior division of internal iliac artery.
2.Venous drainage-
• Prostatic venous plexus in communication with
pudendal plexus to the deep dorsal vein.
VARIANT ANATOMAY
1. Absence of middle lobe
2. Presence of a 4th lobe

49. PATHOLOGY
1. Benign prostatic hyperplasia(BHP)-
• Increase in volume of the prostate.
• Central gland is enlarged and is hypoechoic or of mixed echogenicity.
• Calcification may be seen both within the enlarged gland as well in
pseudocapsule.
• Post micturition residual volume elevated.
• Associated bladder wall hypertrophy and trabeculation.
• Grading of BHP-1. GRADE 1- 20-40 CC of volume
• 2. GRADE 2- 40-60 CC of volume
• 3. GRADE 3 – Above 60 cc of volume
2. Prostate cancer- most common primary malignant tumour in men.seen
as hypoechoic lesion in the peripheral zone of gland but can be hyperechoic
or isoechoic.
3.Prostatis
4.Prostate calcification
5.Prostate cystic disease
6.Prostatic abscess
7.Prostate sarcoma
8.Prostate cyst

50. USG IMAGE OF BHP

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