Indications This view is useful in visualizing calcifications anywhere along the renal tract (i.e. kidneys, ureters, bladder, urethra). It is also used as baseline/interval images in contrast studies (i.e. intravenous urography). Patient position the patient is supine, lying on their back, either on the x-ray table (preferred) or a trolley patients should be changed into a hospital gown, with radiopaque items removed (e.g. belts, zippers, buttons, ECG electrodes) the patient should be free from rotation; both shoulders and hips equidistant from the table/trolley the x-ray is taken on full inspiration this causes the diaphragm to contract, hence compressing the abdominal organs, allowing all renal contents to be visualized on a single image ADVERTISEMENT: Supporters see fewer/no ads Technical factors AP projection centering point the midsagittal point (equidistant from each ASIS) at the level of the iliac crest collimation laterally to the lateral abdominal wall superior to the upper kidney pole inferior to the inferior pubic rami orientation portrait detector size 35 cm x 43 cm exposure 70-80 kVp 30-120 mAs; AEC should be used if available SID 100 cm grid yes Image technical evaluation ensure visualization of the upper poles of both kidneys even if the diaphragm was not imaged the abdomen should be free from rotation with symmetry of the: ribs (superior) iliac crests (middle) obturator foramen (inferior) Practical points In male patients, it is acceptable to perform imaging with collimation extending inferior to the pubic symphysis as there may be renal calculi in the urethra too. Exposure will need to be adjusted according to the imaging system (CR or DR) and patient size. Where possible, a higher kVp should be used in the evaluation of radiopaque objects. References Incoming Links Related articles: Radiographs (adult) Promoted articles (advertising) Cases and figures Figure 1: location of kidneys (annotated image) Case 1: normal KUB Case 2: normal intravenous urogram Case 3: right staghorn calculus Case 4: urethral calculus Case 5: left renal calculus Case 6: medullary nephrocalcinosis with ureteric calculi Articles By Section: Anatomy Approach Artificial Intelligence Classifications Gamuts Imaging Technology Interventional Radiology Mnemonics Pathology Radiography Signs Staging Syndromes By System: Breast Cardiac Central Nervous System Chest Forensic Gastrointestinal Gynaecology Haematology Head & Neck Hepatobiliary Interventional Musculoskeletal Obstetrics Oncology Paediatrics Spine Trauma Urogenital Vascular Cases Breast Cardiac Central Nervous System Chest Forensic Gastrointestinal Gynaecology Haematology Head & Neck Hepatobiliary Interventional Musculoskeletal Obstetrics Oncology Paediatrics Spine Trauma Urogenital Vascular Not Applicable Radiopaedia.org ABOUTIndications This view is useful in visualizing calcifications anywhere along the renal tract (i.e. kidneys, ureters, bladder, urethra). It is also used as baseline/interva

1. EMBRYOLOGY OF KUB
MODERATOR:DR.MALLIKARJUNAPPA.B
PRESENTER:DR.VINAYA

2. INTRODUCTION
Urinary and genital systems are closely associated in their development.
Two embryonic structures play an important role in the development of the
urogenital system are the intermediate mesoderm and the cloaca.

3. Intermediate Mesoderm
• Intraembryonic mesoderm is subdivided into three parts
1. Paraxial mesoderm which becomes segmented to form the somites.
2. Lateral plate mesoderm in which the intraembryonic coelom appears.
3. Intermediate mesoderm lying between the two.

4. Before head fold the intermediate mesoderm is between paraxial mesoderm and
coelomic cavity in lateral plate mesoderm.
 After the folding of the embryonic disc and the formation of the peritoneal cavity,
the intermediate mesoderm forms a bulging on the posterior abdominal wall lateral
to the attachment of the dorsal mesentery of the gut.
It is known as urogenital ridge.
Its surface is covered by the epithelium lining the peritoneal cavity – coelomic
epithelium.

5. The urogeital ridge is divided into two parts.
The medial part is called the genital ridge that gives rise to the genital system.
The lateral part, the nephrogenic cord that forms the urinary system.
The nephrogenic cord extends from the cervical region to the sacral region of
embryo.
In relation to the nephrogenic cord-
Excretory renal tubules – para,meso and metanephric are formed.
Nephric duct-which in later stages becomes the mesonephric duct.
Paramesonephric duct, formed lateral to the nephric duct.
Gonads(testis or ovary) which develops from the coelomic epithelium.

6. Characteristics of Each System
Pronephros:
Rudimentary and nonfunctional.
Mesonephros:
Functional briefly during early fetal development.
Metanephros:
Forms the permanent kidney.
Development Timeline
Sequential development from pronephros to metanephros.
Mesonephros functions temporarily during early fetal period.
Significance of Metanephros
Critical role in forming the permanent and functional kidney.
The third and final system that persists in postnatal life.

7. CLOACA
 The part of hindgut caudal to allantois is called cloaca.
It is divided by the urorectal septum into- the dorsal primitive rectum and the ventral
primitive urogenital sinus.
In further development, the primitive urogenital sinus is subdivided into
a cranial part, called the vesicourethral canal,
a caudal part, called the definitive urogenital sinus.
Still later, the definitive urogenital sinus shows a division into
a cranial- pelvic part, and a caudal- phallic part .

8. DEVELOPMENT OF KIDNEYS
 • The definitive human kidney arises from two distinct sources.
The secretory part, i.e. excretory tubules (or nephrons) are derived from the
lowest part of the nephrogenic cord.
This part is the metanephros, the cells of which form the metanephric
blastema.
 The collecting part of the kidney is derived from a diverticulum called the
ureteric bud
Ureteric bud arises from the lower part of the mesonephric duct.

9. As the ureteric bud grows cranially toward the metanephric blastema, its
growing end becomes dilated to form an ampulla.
The ampulla divides repeatedly.
The first three to five generations of branches fuse to form the pelvis of
kidney.
The next divisions become the major calyces while further divisions form the
minor calyces and collecting tubules.

10. The cells of the metanephric blastema in contact with an ampulla undergo
differentiation to foum a nephron.
Loosely arranged cells of the metanepric blastema form solid clumps in relation to
the ampulla.
Each solid clump is converted into a vesicle.
The vesicle soon becomes pear-shaped and opens into the ampulla.
The vesicle now becomes an S-shaped tube.
Its distal end comes to be invaginated by a tuft of capillaries which form a
glomerulus.

12. Ascent of the Kidney
The definitive human kidney is derived from the metanephros and lies in the
sacral region in the initial stages of development.
In subsequent development of the embryo, differential growth of the abdominal
wall causes the kidney to ascend to the lumbar region
The metanephros, at first, receives its blood supply from the lateral sacral
arteries, but with its ascent, higher branches of the aorta take over the supply.
During ascent, the kidneys pass through the fork like interval between the right
and left umbilical arteries.
 If the arteries come in the way of ascent, the kidney may remain in the sacral
region.

13. Rotation of the Kidney
The hilum of the kidney at first faces anteriorly.
The organ gradually rotates so that the hilum comes to face medially.
Clinical correlation:
Anomalies of kidneys
 One or both kidneys may be absent -agenesis.
The kidney may be underdeveloped (hypoplasia)
Overdeveloped (hyperplasia)
Distention of the pelvis with urine –hydronephrois, may occur
as a result of obstruction in the urinary passages.
 Duplication: There maybe an extra kidney on one side.
It may be separate, or may be fused to the normal kidney

14. • Anomalies of shape:
Horse shoe kidney- the lower poles of the two kidneys maybe fused.
A horseshoe kidney does not ascend higher than the level of the inferior mesenteric
artery as the it prevents its higher ascent.
 Pancake kidney: The two kidneys may form one mass, lying in the midline or on
one side. The two kidneys may lie on one side, one above the other, the adjacent
poles being fused.
Lobulated kidney: The fetal kidney is normally lobulated. This lobulation may
persist

16. Anomalies of position:
- The kidneys may fail to ascend. They then lie in the sacral region.
-The ascent of the kidneys may be incomplete as a result of which they may
lie opposite the lower lumbar vertebrae.
-The kidneys may ascend too far, and may even be present within the
thoracic cavity.
- Both kidneys may lie on one side of the midline. They may lie one above the
other or side by side .
-The ureter of the displaced kidney crosses to the opposite side across the
midline.
- Both kidneys may be displaced to the opposite side. The two ureters then
cross each other in the midline

17. Abnormal rotation:
-Non-rotation: The hilum is directed forward.
-Incomplete rotation: The hilum is directed anteromedially.
-Reverse rotation: The hilum is directed anterolaterally.
Congenital polycystic kidney.:
-Failure of the excretory tubules of the metanephros to establish contact with
the collecting tubules, leads to the formation of cysts.
-Isolated cysts are commonly seen, but sometimes the whole kidney is a mass of
such cysts.
-The cysts press upon normal renal tissue and destroy it.

18. Aberrant renal arteries:
 The kidney may receive its blood supply partially or entirely, from arteries
arising at an abnormal level.
In the case of non ascent, or of incomplete ascent, the aberrant arteries may
constitute the only supply to the organ.
 An aberrant artery may be the only source of arterial blood to a segment of
the kidney.
 It may press upon the ureter and cause obstruction, leading to
hydronephrosis.
Multiple anomalies: Two or more of the anomalies may coexist.
Anomalies of position are frequently associated with those of rotation.

19. DEVELOPMENT OF THE URETER:
The ureter is derived from the part of the ureteric bud that lies between the
pelvis of the kidney, and the vesicourethral canal.
Anomalies of the ureter:
The ureter maybe partially or completely duplicated.
Of the two ureters, one may open into the urinary bladder and the other at an
abnormal sites.
Instead of opening into the urinary bladder, the ureter may end in the prostatic
ureter, ductus deferens, seminal vesicles, or rectum in the male.
In the females- in the urethra, vagina, vestibule or rectum.

20. The upper end of the ureter may be blind, it is not connected to the kidney.
• The ureter may be dilated (hydroureter) because of obstruction to urine flow.
• The ureter may have valves or diverticula.
• The right ureter may pass behind the inferior vena caya. It then hooks around
the left side of the vena cava; this may result in kinking and obstruction of the
ureter.

21. DEVELOPMENT OF THE URINARY BLADDER
 The part of primitive urogenital sinus above the openings of the mesonephric
ducts is called vesicourethral canal.
It presents a wider upper part and a narrower lower part.
 The allantois opens into the apex of the upper wider part of vesicourethral canal.
The urinary bladder develops from the dilated part of vesicourethral canal.
The lower narrow part of vesicourethral canal becomes the primitive urethra.
Anomalies of urinary bladder:
The bladder may be absent or may be duplicated.
The lumen may be divided into compartments by septa.
The bladder maybe divided into upper and lower compartments –hourglass
bladder because of a constriction in the middle.
The bladder may communicate with rectum.
Ectopia vesicae: The lower part of the anterior abdominal wall, as well
as the ventral wall of the bladder, may be missing

23. DEVELOPMENT OF THE FEMALE URETHRA
The female urethra is derived from the caudal part of the vesicourethral canal
(endoderm).
DEVELOPMENT OF THE MALE URETHRA:
• The part of the male urethra extending from the urinary bladder upto the openings
of the ejaculatory ducts is derived from the caudal part of vesicourethral canal.
The posterior wall of this part is derived from abdorbed mesonephric ducts.
The rest of the prostatic urethra, and the membranous urethra, are derived from the
pelvic part of the definitive urogenital sinus.
The penile part of the urethra is derived from epithelium of the phallic part of the
definitive urogenital sinus.
The terminal part of penile urethra is derived from ectoderm.

24. Anomalies of urethra:
There maybe obstruction to the urethra at its junction with the bladder.
The urethra may show diverticula.
It maybe duplicated.
The urethra may have abnormal communications with rectum, vagina, ot
ureter.
Hypospadias and epispadias.

25. THANK YOU.