Development and congenital anomalies of urogenital system


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Development and congenital anomalies of urogenital system

  1. 1. Development and congenital anomalies of urogenital system Moderator : Dr. (Mrs) Nabanita Deka Asst. Professor Presenter : Dr. Jayeta Choudhury Department of Radiology Gauhati Medical College
  2. 2. Functionally, the urogenital system can be divided into two entirely different components: the urinary system and the genital system. Embryologically and anatomically, however, they are intimately interwoven. Both develop from a common mesodermal ridge (intermediate mesoderm) and open into a common channel the cloaca.
  3. 3. “Ontogeny Recapitulates Phylogeny” Ernst Haeckel 1860  Ontogeny is the development of the individual  Phylogeny is the evolution of the species  So this is the idea that during development an organism (or an organ) goes through the same stages as during their evolution. The kidneys are a perfect example.
  4. 4. URINARY SYSTEM : Kidney Systems • Three slightly overlapping kidney systems are formed in a cranial-tocaudal sequence during intrauterine life in humans: the pronephros, mesonephros, and metanephros. PRONEPHROS • Beginning of the 4th wk (21days). •The pronephros is represented by 7 to 10 solid cell groups in the cervical region . •Their excretory units: are called nephrotomes. •By the end of the fourth week, all indications of the pronephric system regress.
  5. 5. MESONEPHROS •Appear late in the 4th wk • From the thoracic and lumbar seg of intermediate mesoderm. •They function as interim kidneys for approximately 4 wks. • Excretory tubules form their basic unit which open into mesonephric ducts. •The mesonephric ducts open into the cloaca.
  6. 6. METANEPHROS: THE DEFINITIVE KIDNEY •Appears in the 5th wk. •Develops from sacral segments of the intermediate mesoderm . •However, the development of the duct system differs from that of the other kidney systems. COLLECTING SYSTEM Collecting ducts of the permanent kidney develop from the URETERIC BUD, an outgrowth of the mesonephric duct close to its entrance to the cloaca . The bud penetrates the metanephric tissue, which is moulded over its distal end as a cap . Subsequently, the bud dilates, forming the primitive renal pelvis, and splits and subsequently divides and sub divides to finally give rise to approximately 1 to 3 million collecting tubules.
  7. 7. Hence, the kidney develops from two sources: (a) metanephric excretory units and (b) the ureteric bud, which gives rise to the collecting system. At birth, the mesoderm, which provides kidneys have a lobulated appearance, but the lobulation disappears during infancy .
  8. 8. POSITIONAL CHANGES OF THE KIDNEYS • Initially : close/ pelvic / anterior to the sacrum . • Gradually come to lie in the abdomen and move farther apart . • Attain their adult position by 9th wk. This relative ascent results mainly from the growth of the embryo's body caudal to the kidneys . • Initially the hilum : faces ventrally; however, as the kidney relocates (ascends), it rotates medially almost 90 degrees. • By the 9th week, the hilum is directed anteromedially .
  10. 10. Initially, the bladder is continuous with the allantois, but when the lumen of the allantois is obliterated, a thick fibrous cord, the urachus, remains and connects the apex of the bladder with the umbilicus . In the adult, it forms the median umbilical ligament.
  12. 12. GENITAL SYSTEM •Sex differentiation is a complex process that involves many genes. •The key to sexual dimorphism is the Y chromosome, which contains the testis-determining gene called the SRY (sex-determining region on Y) gene in its short arm (Yp11).
  13. 13. Indifferent embryo • Weeks 1-6 sexually indifferent or undifferentiated stage • Week 7 begins phenotypic sexual differentiation. • The sex of the fetus may be discerned by ultrasound as early as 12 weeks gestation. However, it can be determined with 95-100% accuracy only at or after 20wks.
  14. 14. At day 8, cells of the inner cell mass of the blastocyst differentiate into : hypoblast and epiblast layers. Primordial germ cells originate in the epiblast, migrate through the primitive streak, and by the 3rd week reside among endoderm cells in the wall of the yolk sac close to the allantois. During the 4th week, they migrate by ameboid movement along the dorsal mesentery of the hindgut , to reach the primitive gonads in the genital ridges. The gonadal ridges appear as a pair of longitudinal ridges, on either side of midline. The primordial germ cells have an inductive influence on the development of the gonad into ovary or testis.
  15. 15. Shortly before and during arrival of primordial germ cells, the epithelium of the gonadal ridge proliferates, and epithelial cells penetrate the underlying mesenchyme. Here they form a number of irregularly shaped cords, the primitive sex cords . These sex cords and the germ cells make up the ovary and testis.
  17. 17. Genital Ducts in the Female • The paramesonephric duct arises as a longitudinal invagination of the epithelium on the anterolateral surface of the urogenital ridge . • Cranially, the duct opens into the abdominal cavity with a funnel-like structure. Caudally, it first runs lateral to the mesonephric duct, then crosses it anteriorly to fuse with the duct from the other side in the midline. • The two ducts are initially separated by a septum but later fuse to form the uterine canal.
  18. 18. Fate of the mesonephric duct, mesonephric ductules and parameso nephric duct Mesonephric duct Epididymis, vas defferens, seminal vesicles and ejaculatory duct in males Degenerates except for some remnants e.g. duct of epoophoron, duct of paroophoron and Gartner's duct Mesonephric ductules * Efferrent ductules * Paradiddymis *Appendix of epididymis Females : tubules of epoophoron and paroophoron. Paramesonephric duct -Cranial end forms the appendix testis. - Caudal end formis the prostatic utricle. Fallopian tubes, uterus and 4/5ths vagina
  19. 19. Formation of the broad ligament
  20. 20. Formation of the vagina Thus, the vagina has a dual origin : with the upper portion (four fifth) derived from the uterine canal the lower portion derived from the urogenital sinus.
  21. 21. EXTERNAL GENITALIA : INDIFFERENT STAGE In the 3rd wk, mesenchyme cells originating in the region of the primitive streak migrate around the cloacal membrane to form a pair of slightly elevated cloacal folds.
  25. 25. ANOMALIES OF FORM  Renal Agenesis  Renal Hypoplasia  Supernumerary kidney
  26. 26. RENAL AGENESIS  Unilateral renal agenesis : • 1 in 1000 • Males / left kidney • Unilateral renal agenesis should be suspected in infants with a single umbilical artery • The term LYING DOWN ADRENAL SIGN as been ascribed to the elongated appearance of the adrenal not normally molded by the adjacent kidney  Bilateral renal agenesis : • 1 in 5000 • Results when the ureteric bud fails to develop or it fails to penetrate the metanephrogenic blastema • Is incompatible with postnatal life because of the associated pulmonary hypoplasia. • There is associated with oligohydramnios. • These infants have a characteristic facies, club feet and other anomalies called “ POTTER’S SEQUENCE”
  27. 27. RENAL HYPOPLASIA : • Unusual renal anomaly in which the kidney is at least 50% smaller than normal and typically contains fewer than the normal number of calyces. • Usually unilateral, and the kidney functions normally for its size. • There are varoius acquired causes of unilaterally small kidneys . • Can be differentiated from hypoplasia : * by the normal number of calyces * and normal cupping of the calyces • The ASH-UPMARK KIDNEY was prevoiusly thought by some to be a variant of renal hypoplasia. However, it is currently thought to be caused by scarring due to chronic pyelonephritis with cortical loss at its upper pole.
  28. 28. SUPERNUMERARY KIDNEY • A supernumerary kidney is extremely rare. • Cleavage of the metanephric blastema has been suggested as the cause for this abnormality. •Most supernumerary kidneys are caudally placed and are hypoplastic. • They may be connected to the ipsilateral dominant kidney either completely or by loose areolar connective tissue.
  29. 29. ANOMALIES OF POSITION • Malrotated kidneys • Ectopic kidneys
  30. 30. MALROTATED KIDNEYS If a kidney fails to rotate, the hilum faces anteriorly, that is, the fetal kidney retains its embryonic position . If the hilum faces posteriorly, rotation of the kidney proceeded too far; if it faces laterally, lateral instead of medial rotation occurred. Abnormal rotation of the kidneys is often associated with ectopic kidneys.
  31. 31. RENAL ECTOPIA • Renal ectopia results from failure of normal ascent of the embryonic kidney. • Ectopic kidneys lie outside the renal fossa and may be: ^pelvic ^lie opposite the sacrum ^ below the aortic bifurcation ^iliac ^ thoracic ^ crossed . • They are often small, lobulated kidneys with abnormal rotation with extrarenal pelvis and an irregular vascular supply. •The most common problem associated with an ectopic kidney is vesicoureteric reflux (VUR) (85%), pelvi-ureteric junction (PUJ) obstruction (3352% ) and renal calculi .
  32. 32. ANOMALIES OF FUSION • These anomalies are thought to result because of an abnormally situated umbilical artery that prevents normal cephalic migration from occurring. • In all fused kidneys, the arterial supply and venous drainage are grossly abnormal.
  33. 33. HORSESHOE KIDNEY • 1 in 400 • Horseshoe kidney is the most common renal fusion anomaly.(90%) • It consists of two distinct functioning kidneys lying vertically on either side of the midline, connected at their lower poles by an isthmus of functioning renal parenchyma or, rarely, fibrous tissue that crosses the midline of the body . • In rare instances, the upper poles may be the site of fusion.
  34. 34. • The position of the isthmus and hence the kidneys are variable :  40% : the isthmus lies at level of L4 just below the origin of the IMA  Another 40% : the isthmus is located in a normal anatomical position of the kidneys  Remaining 20% :kidneys lie lower in the pelvis
  35. 35. • Ureters may have the so-called “FLOWER-VASE APPEARANCE” , in which the upper ureters diverge laterally over the isthmus and then converge inferiorly. • Because of their abnormal course, the ureters are prone to be obstructed, precipitating hydronephrosis, infection and stone formation. • Some authours have reported HSK to be associated with increased risk for renal neoplasms such as Wilms tumors, renal carcinoids, and transitional cell carcinoma.
  36. 36. CROSSED FUSED RENAL ECTOPIA • Incidence : 1 in 1000 • 2 : 1 male •The left kidney is most frequently ectopic, 3 : 1 • Origin : abnormal migration of ureteral bud. • One kidney crosses over to opposite side, and the parenchyma of the two kidneys fuse. • Most commonly, the upper pole of the inferiorly positioned crossed ectopic kidney is fused to the lower pole of the superior, normally positioned kidney. The ureter of the ectopic kidney crosses the midline and enters the bladder on the opposite side .
  37. 37. McDonald and McClellan classified crossed ectopic kidney into four types: crossed renal ectopia with fusion (85%), crossed renal ectopia without fusion (10%), solitary crossed renal ectopia and bilaterally crossed renal ectopia . Six variations of crossed fusion have been described. In decreasing order of frequency, they are type 1: inferior crossed fused ectopia type 2: sigmoid or S-shaped kidney type 3 :unilateral lump kidney type 4: unilateral disc kidney type 5: L-shaped kidney type 6: superior crossed fused ectopia
  38. 38. CAKE KIDNEY (COMPLETE RENAL FUSION) • Pan Cake kidney is a rare congenital anomaly of the genitourinary system,with fewer than 30 cases described in the literature . •The term cake kidney or fused pelvic kidney was defined by Glenn as an anomaly in which “the entire renal substance is fused into one mass, lying in the pelvis, and giving rise to two separate ureters which enter the bladder in normal relationship” •In rare instances, such kidneys possess one ureter . •The fused kidney occupies prevertebral or presacral space . •The cake kidney may remain asymptomatic and be detected at autopsy. •It may become infected or may cause local pain from dragging on the renal vessels by the weight of the organ
  40. 40. CONGENITAL CYSTIC RENAL DISEASES • Renal cysts detected in utero and after birth has been a topic of considerable confusion. • A standardized step-by-step sonographic approach is most helpful in differentiating renal cystic diseases. • This approach must be combined with the clinical data, familial history, and in some cases, complementary examinations.
  41. 41. Once renal cystic disease is suspected, the first step is to rule out Dysplasia associated with obstructive uropathy the features of which include: • Dilated PCS • Hyperechoic kidneys • Multiple cysts • Can be normal, enlarged or small/ Unilateral or Bilateral Next step is to consider Multicystic Dysplastic kidneys: • Multiple cysts throughout the kidney without communication. • No renal parenchyma in between • Unilateral • Atretic ureter • Vascular pedicle may also be absent or atretic
  42. 42. Both obstructive dysplasia and MCDK should be differentiated from complex cysts, which include cystic tumors like renal lymphangioma
  43. 43. If the foregoing diagnoses are unlikely, inherited renal cystic disease should be considered. If no familial history is present, cases are further split  patients with renal findings limited to the kidney  renal anomalies are associated with other organ malformations Both these groups can be separated into  those with typical ultrasound patterns suggestive of specific diagnoses  those with atypical ultrasound patterns.
  44. 44. The ARPKD pattern: • Bilateral, very large (> 4 SD) kidneys • Diffusely hyperechoic kidneys • Loss of CMD with or without evident cysts • Oligohydramnios is the rule • Very large hyperechoic kidneys with hyperechoic medulla (reversed CMD) is another typical pattern.
  45. 45. •The next step is to rule out Glomerular cysts (GCKD) (AD): • It also includes hyperechoic and enlarged (+2 SD) kidneys without CMD but there are charecteristic multiple subcapsular as well as cortical cysts.
  46. 46. Third typical pattern is Nephronophthisis: • autosomal recessive tubulointerstitial ciliopathies • urinary concentration defects and anemia At ultrasound :  the kidneys are hyperechoic, normal-sized or small, and without CMD.  renal cysts typically develop at the corticomedullary junction
  47. 47. Multiple congenital syndromes are also associated with renal cysts. These should also be kept in mind while dealing with a case of renal cysts in utero or in a child . This includes : •Bardet-Biedl syndrome (BBS) •Meckel-Grüber syndrome •Joubert syndrome •Tuberous Sclerosis
  48. 48. ANOMALIES OF RENAL PELVIS AND URETER - Polycalicosis and Congenital Megacalyces - Calyceal diverticula - Microcalyx - Aberrant (Ectopic) Papilla - Ureteropelvic Junction Obstruction - Congenital Megaureter - Duplex Collecting Systems
  49. 49. CONGENITAL MEGACALYCES/ PUIGVERT'S DISEASE Calyces are asymmetrically dilated. Renal pelvis is normal. Some doubt its congenital nature.
  50. 50. CALYCEAL DIVERTICULUM EXCRETORY PHASE • 4.5 : 1000 • Focal extrinsic dilatation of a renal calyx • In 1/3 patients : stones can form within these. DELAYED IMAGES
  51. 51. URETEROPELVIC JUNCTION OBSTRUCTION • Congenital obstruction of the UPJ is a common anomaly of the urinary tract. • The disorder produces caliectasis and marked pelviectasis as a result of a functional narrowing of the UPJ. • In 5% cases : extrinsic compression by an aberrant renal artery • Males (2:1), Left sided • Commonly presents as an abdominal mass in a neonate. • In some cases, symptoms may present in the setting of a sustained diuresis, a condition that has become known as "beer-drinker's hydronephrosis."
  52. 52. On urography, a dilated renal pelvis and calyces will be demonstrated. Because of the dilation, slow opacification of the affected side is the rule and delayed radiographs are usually necessary. DIFFERENTIATING UPJ FROM EXTRA RENAL PELVIS IS IMPORTANT. Normal calyces Dilated calyces RGP RGP
  53. 53. • USG and CT reveal similar findings. • In patients with equivocal UPJ obstruction, or in cases where there is a discrepancy between the patient's clinical symptoms and the radiologic findings, diuresis renography or the Whitaker procedure may be employed.
  54. 54. DUPLICATION OF THE URETER : • Results from early splitting of the ureteric bud . • Duplication can be variable. At one end of the spectrum there is merely duplication of the renal pelvis, draining via a single ureter. At the other extreme, two separate collecting systems drain independently into the bladder or ectopically (see below) • Duplex systems may be unilateral (more common) or bilateral. •Partial or complete. Duplication of a renal pelvis (1 in 40) : Duplication of a renal pelvis is the most common congenital abnormality of the upper renal tract .
  55. 55. . The upper pole ureter The lower pole moiety • drains inferomedially • can drain ectopically • usually associated with an ureterocele • drains superolaterally • is usually associated with VUR • CT is able to delineate essentially all abnormalities, especially when performed during the excretory phase. A duplicated renal collecting system can be suspected by identifying the so called faceless kidney .
  56. 56. Faceless Kidney Sign
  57. 57. Drooping Lily Sign
  58. 58. PRIMARY MEGAURETER : • Megaureter is a generic term indicating the presence of an enlarged ureter with or without concomitant megacalyces. • The normal ureter in children rarely exceeds 5 mm in diameter . In practice, a ureter with a diameter of 7 mm or more should be considered a megaureter . • There are three major categories of primary megaureter: obstructed primary megaureter refluxing primary megaureter nonrefluxing unobstructed primary megaureter •Secondary megaureter occurs as a result of some abnormality involving the bladder or urethra (eg, urethral valves, strictures, ureteroceles etc)
  59. 59.  Obstructed primary megaureter: a condition akin to achalasia and Hirschsprung disease. The normal ureter proximal to the aperistaltic segment dilates because of relative obstruction. There is associated hydronephrosis, and active peristaltic waves can be seen on ultrasound.  Refluxing primary megaureter :is caused by a short or absent intravesical ureter, congenital paraureteric diverticulum, or other : derangement of the VUJ. Vesicoureteric reflux can be demonstrated in this.  Nonrefluxing unobstructed primary megaureter: there is neither reflux nor stenosis of the vesicoureteral junction, but the ureter is dilated beginning at a point just above the bladder . Most primary megaureter in neonates fall into this category.
  61. 61. ECTOPIC URETER •Ectopic insertion of the ureter occurs due to abnormal ureteral bud migration and usually results in caudal ectopia. •70% are associated with complete ureteral duplication. • In the female, it can insert urethra, vestibule, or vagina. More rarely, it can empty into the uterus or Gartner duct or cyst. • In males, it empties into the lower bladder, posterior urethra, seminal vesicle, vas deferens, or ejaculatory duct. In very rare instances, it can empty into the rectum.
  62. 62. VESICO URETERAL REFLUX • VUR is the abnormal flow of urine from the bladder into the upper urinary tract. • Cause :  primary maturation abnormality of the VUJ  short distal ureteric submucosal tunnel  due to an associated congenital anomaly • Reflux predisposes to renal infection (pyelonephritis). • The majority of pediatric patients who develop renal scars after a urinary tract infection have VUR. • Detection of VUR in neonates and infants is particularly important because these patients are more predisposed to the development of renal scars and renal failure than are older children.
  63. 63. • Reflux is also the most common cause of antenatal hydronephrosis (40%) •The primary diagnostic procedure for evaluation of VUR is VCUG, which should be performed after the first episode of urinary tract infection. • VCUG should be used to document the presence of VUR and to determine the grade of reflux and whether reflux occurs during micturation or during bladder filling.
  64. 64. Grades of VUR Based on Guidelines of the International Reflux Study Committee Echo-enhanced cystosonography has recently been proposed as a promising new method for detecting and grading VUR without exposing patients to ionizing radiation.
  65. 65. URETEROCELES • Ureteroceles represent cystic dilatation of the intravesical segment of the ureter. • The defect is in the obstruction of the meatus, and the ureterocele is simply a hyperplastic response to this obstruction with the bladdder and ureteral mucosa prolapsing out. • They may be  Simple 25% - a ureterocoele that occurs at a VUJ in a normal position  Ectopic 75% - that which occurs at a VUJ whose site is abnormal (duplex ureter)
  66. 66. IMAGING :  At US: the ureterocele is identified as a cystic intravesical mass, contiguous with a dilated ureter.  In IVP: demonstrates a collection of contrast material within the ureterocele : which produces the classic “cobra head” appearance consisting of a round or oval area of increased opacity surrounded by the radiolucent halo of the wall of the ureterocele.  In VCUG: a ureterocele usually manifests as a rounded filling defect within the bladder.
  67. 67. PRUNE BELLY SYNDROME • is also called Eagle-Barrett syndrome • exclusively in males • Renal anomalies include Kidneys: normal or dysplastic Ureters: dilated : segmental or total / VUR Bladder: large/ Patent urachus (lacks trabeculations) Dilated posterior urethra : PUV like picture
  68. 68. ABNORMALITIES OF THE BLADDER - Exstrophy - Bladder Duplication - Bladder diveriticulum - Bladder ears
  69. 69. VESICAL EXSTROPHY COMPLEX • • • • Depending on the timing of the intrauterine insult, defect in lower anterior abdominal wall defect and premature perforation of the cloacal membrane results in a spectrum of diseases. 30% are epispadias, 60% are classic bladder exstrophy, and less than 10% are cloacal exstrophies. Incidence of bladder exostrophy : 0.25-0.5 per 10,000 births Males ( 2:1) Ante natal USG findings : Lower abdominal wall defect with protruding abdominal mass. Absence of the normally filled urinary bladder. No sign of oligohydramnios or other gross renal abnormalities Colour Doppler shows umbilical arteries alongside the abdominal wall mass External genitalia malformation, pubic diastasis etc
  70. 70. BLADDER DUPLICATION • Can be complete or incomplete. • In incomplete bladder duplication, two bladders communicate with each other and drain into a common urethra. • Complete duplication is very rare : 40 cases in surgical literature • Duplication of the bladder may occur in the sagittal or coronal plane. The most common form is sagittal duplication with the bladders lying side by side. • Each bladder receives the ureter of the ipsilateral kidney and is drained by its own urethra.
  71. 71. BLADDER DIVERTICULA • Congenital BD : occur without obstruction • Male predominance • Described as herniation of mucosa through bladder musculature. • Usually > 2cm, solitary • Types : 90% paraureteral : associated with VUR : “ Hutch Divericula” 10 % postero-lateral : not associated with VUR
  72. 72. URACHAL ABNORMALITIES Patent urachus Urachal Cyst Urachal-umbilical sinus Vesicourachal diverticulum
  73. 73. CONGENITAL URACHAL REMNANT ABNORMALITIES • Refers to a series of potential anomalies that can occur in association with the urachus. • There are four types of congenital urachal remnant anomalies. They are • • • • Patent urachus : commonest ~ 50 % Urachal Cyst : next commonest : ~ 30 % Urachal-umbilical sinus : ~ 15 % Vesicourachal diverticulum : ~ 5 % Usually midline : may occasionally deviate laterally to merge with one of the obliterated umbilical arteries
  74. 74. ABNORMALITIES IN THE MALE URETHRA • Diverticulae • Absent phallus/ agenesis of urethra - Posterior urethral - Anterior urethral • Hypospadias • Congenital megalourethra • Congenital urethral duplication • Posterior urethral polyp • Congenital urethral fistulae • Prostatic utricle • Posterior urethral valve • Congenital meatal stenosis • Anterior urethral valve • Congenital urethral stenosis
  75. 75. POSTERIOR URETHRAL VALVES • M.C congenital obstructive lesion of urethra, occurring only in phenotypic boys. • Speculated to be a result of abnormal insertion of the mesonephros into cloaca. • It courses obliquely from the verumontanum to the most distal portion of the prostatic urethra in a bicuspid or unicuspid fashion. • VUR with gross hydronephrosis, dysplastic kidneys, and urine ascites are common findings in such a patient.
  76. 76. HYPOSPADIAS The urethral meatus is located on the ventral surface, anywhere from the penile shaft to the penoscrotal region
  77. 77. ANTERIOR URETHRAL VALVES •These are rare congenital anomalies that cause lower urinary tract obstruction in children. •Anterior urethral valves may be found anywhere in the anterior urethra. •Most commonly in bulbar urethra.
  78. 78. CONGENITAL URETHRAL DUPLICATION It is a rare anomaly. Commonly ,the duplication commonly occurs in the sagittal plane. Effmann Class. I : Blind ending I I A: double meatus I I: Patent assesory urethra I I B: single meatus III : Assesory urethra from duplicated bladder
  79. 79. MULLERIAN DUCT CYSTS AND PROSTATIC UTRICLE MULLERIAN DUCT CYSTS • Nonatrophy of the mullerian duct may produce cystic dilations along the route of the vas deferens from the scrotum to the ejaculatory ducts . • Mullerian duct cysts are rare, but most commonly occur in the midline just above the prostate. PROSTATIC UTRICLE • The prostatic utricle is a small, blind-ending midline pouch arising from the prostatic urethra at the level of the verumontanum. • The normal prostatic utricle is 8 to 10 mm in length, narrow at its orifice (2 mm). • It may be associated with urinary retention, stasis, and infection.
  80. 80. URETHRAL DIVERTICULUM • Anterior urethral diverticula : obstruction • Posterior urethral diverticula : complicated by urinary stasis, infection, and calculi formation.
  81. 81. CONGENITAL MEGALOURETHRA This is a rare congenital anomaly resulting from the faulty development of the corpora cavernosa and corpus spongiosum. Two types are described. Milder form : scaphoid variety. More severe form : fusiform variety
  83. 83. MULLERIAN DUCT ANOMALIES Phase of Organogenesis : one or both ducts may not develop completely leading to complete agenesis / hypoplasia / unicornuate anomalies. Phase of lateral fusion : where the lower segments of the Mullerian ducts fuse to form uterus, cervix and upper 4/5 ths vagina. Failure of this could lead to Bicornuate or Didelphys anomalies. Vertical fusion is referred to ascending sinovaginal bulb fusion to descending Mullerian system. Incomplete fusion would produce transverse vaginal septum. Septal resorption : After lower Mullerian system fuses, septum which is present gets resorbed naturally. Failure leads to septate uterus anomaly.
  84. 84. • Developed by the American Fertility Society (AFS) • Developmental anomalies of the renal system is common. Renal agenesis is the most commonly reported anomaly, ( 67% ). • Many of the anomalies are initially diagnosed at HSG and USG ; however MR imaging is the study of choice because of its high accuracy and detailed elaboration of uterovaginal anatomy. • Three-dimensional ultrasound with multiplanar imaging has been shown to be more accurate than plain TVS. • Laparoscopy and hysteroscopy are reserved for women in whom interventional therapy is likely to be undertaken.
  85. 85. CLASS I — AGENESIS/HYPOPLASIA (5-10% ) • Early developmental failure of the Mullerian ducts, results in various degrees of agenesis or hypoplasia of the uterus, cervix and upper 4/5 ths of the vagina. • In agenesis a uterus is not identified or small amounts of rudimentary tissue without differentiation may be identified. • The most common form is the Mayer–Rokitansky– Kuster– Hauser syndrome.  90% cases : vaginal + uterine agenesis  10% cases : isolated vaginal agenesis with an obstructed uterus or small rudimentary uterus. On US images, a normal uterus cannot be identified. The ovaries often are normally situated.
  86. 86. On MR images, uterine agenesis and hypoplasia are best characterized on sagittal images, while vaginal agenesis is best demonstrated on transverse images. Agenesis results in no identifiable uterus. Uterine hypoplasia demonstrates small uterus with abnormal low-signal-intensity myometrium on T2-weighted images and poorly delineated zonal anatomy.
  87. 87. CLASS II — UNICORNUATE (20%) This anomaly results from complete or near-complete arrested development of one of the Mullerian ducts. Four possible subtypes can develop: (i)absent horn (ii) non-cavitary (non-functional) rudimentary horn (iii) cavitary communicating rudimentary horn and (iv) cavitary non-communicating rudimentary horn. The embryologic predominance of the unicornuate uterus to be on the RIGHT has not been explained.
  88. 88. HSG : • Fusiform shape : tapering at the apex • Draining into a solitary fallopian tube • The uterus is generally shifted off of midline
  89. 89. USG :
  90. 90. On MR images: • Unicornuate uterus appears curved and elongated • The external uterine contour assumes a banana shape. • Uterine volume is reduced. •The endometrium may be uniformly narrow or may assume a bullet shape, tapering at the apex. • Normal myometrial zonal anatomy is maintained. • The endometrial-to-myometrial width and ratio are reported to be normal .
  91. 91. CLASS III — DIDELPHYS (5%) • This anomaly results from complete non-fusion of both Mullerian ducts. • The individual horns are fully developed and almost normal in size. • Each mullerian duct develops its own hemiuterus and cervix and demonstrates normal zonal anatomy with a minor degree of fusion at the level of the cervices. NO COMMUNICATION IS PRESENT BETWEEN THE DUPLICATED ENDOMETRIAL CAVITIES. • A longitudinal vaginal septum is associated in 75% of these anomalies .
  92. 92. On USG : • Separate divergent uterine horns are identified • With a large fundal cleft • Endometrial cavities are uniformly separate, with no evidence of communication.
  93. 93. MR IMAGING
  94. 94. • Some patients with uterus didelphys present with a unilateral hemivaginal septum, which may result in obstruction with consequent hematometrocolpos . • Majority of cases reported in the literature are associated with renal agenesis on the same side as the obstructing transverse hemivaginal septum. This syndrome has been referred to as OBSTRUCTED HEMIVAGINA–IPSILATERAL RENAL AGENESIS ANOMALY.
  95. 95. CLASS IV — BICORNUATE (10%) • This class is characterised by partial non-fusion of the Mullerian ducts. • This results in a central myometrium separating the uterus that may extend to the level of the internal cervical os (BICORNUATE UNICOLLIS) or external os (BICORNUATE BICOLLIS). The fundal cleft is usually > 1 cm deep. • The horns of the bicornuate uteri are not as fully developed and are smaller than those in the didelphys uteri.
  96. 96. Ultrasound demonstrates two uterine horns (arrows) and a single cervix
  97. 97. The horns demonstrate normal uterine zonal anatomy. The endometrial-to-myometrial ratio and width are normal in appearance.
  98. 98. CLASS V — SEPTATE (55%) • This class of anomaly occurs when the final fibrous septum between the two Mullerian ducts fails to resorb. • This results in the formation of a uterus that is completely or partially divided into two cavities. • The septum may be muscular or fibrous or a combination of both. • This class is associated with the poorest obstetrical outcomes. It has been theorized that the decreased connective tissue may result in POOR DECIDUALIZATION AND IMPLANTATION, while increased muscular tissue may result in INCREASED CONTRACTILITY of the tissue, thereby predisposing the patient to spontaneous abortion. • It is important to distinguish a fibrous septum from a muscular septum, as the former can be repaired by a hysteroscopic approach, whereas the latter may require a transabdominal surgical approach.
  99. 99. US: The echogenic endometrial cavities are separated at the fundus by the intermediate echogenicity of the myometrium and by a hypoechoic fibrous segment caudally. COMPLETE
  100. 100. On MR imaging:
  101. 101. • The differentiation between a septate and bicornuate uterus is important because they differ in their reproductive prognosis and treatment. Bicornuate Features Septate Uterus Uterus • Depth of fundal cleft • Fundal contour • Intercornual angle • Intercornual distance • Intercornual tissue • < 1 cm • > 1 cm • Convex/ flat • Concave • <75 degrees • <4 cm • Fibrous or myometrial • >105 degrees • >4 cm • Myometrial
  102. 102. CLASS VI — ARCUATE • This group is characterised by mild indentation of the endometrium at the uterine fundus . • It is the result of near complete resorption of the uterovaginal septum. • Currently, No Definitive Depth Has Been Established To Differentiate The Arcuate Configuration From The Septate. • This class is highly controversial, as it remains unclear whether this variant should be classified as a true anomaly or as an anatomic variant of normal. • Data regarding the reproductive outcome of patients in this category are extremely limited and conflicting. Currently, it is generally thought that an arcuate uterus is compatible with normal pregnancy and delivery.
  103. 103. CLASS VII — DIETHYLSTILBESTROL RELATED •Several million women were treated with diethylstilbestrol (DES), a non-steroidal oestrogen, to prevent miscarriage between 1945 and 1970 . •The drug was promptly removed from the market when it was foundthat up to 15% of newborn girls who were exposed to DES had UTERINE MALFORMATIONS and an increased risk of VAGINAL CLEAR CELL CARCINOMA . •The uterine abnormalities include hypoplasia and a T-shaped uterine cavity . • Patients may also have abnormal transverse ridges, pseudopolyps and stenoses of the cervix.
  104. 104. MR Evaluation :
  105. 105. TRANSVERSE VAGINAL SEPTUM • Defects of vertical fusion results in a transverse vaginal septum. • It can occur anywhere along the vagina, although it occurs most frequently at the junction of the upper and middle third. •The septum is a membrane of fibrous connective tissue with vascular and muscular components . • There is resultant hematocolpos and hematometra, which is usually less striking, secondary to decreased distensibility of the more muscular myometrium.
  106. 106. UNDESCENDED AND ECTOPIC TESTES •Undescended testis(UDT) is a common genitourinary anomaly in which the testis fails to descend completely and is located along the normal pathway of descent. •Ectopia testis on the other hand is rare with an incidence of <1% of all cases of undescended testes. •Usg is the primary modality. However, if the testis cannot be localised by USG MRI is used. •The testicle is typically low signal on T1 and high signal on T2. The normal testicle exhibits intense diffusion restriction, and these sequences can aid confident identification.
  107. 107. DISORDERS OF SEXUAL DEVELOPMENT - Male pseudohermaphroditism - Female pseudohermaphroditism - True hermaphrodite - Mixed gonadal dysgenesis - Pure gonadal dysgenesis - Persistent mullerian duct syndrome
  109. 109. CONCLUSION Radiologic investigation continues to be one of the most important sources of clinical information in the evaluation of urinary and genital tract disorders. The role of diagnostic imaging is to help determine as closely as possible the exact nature of the abnormality. But the need for radiologic examinations should be carefully weighed to avoid inconveniencing the patient, exposing the patient to unnecessary radiation, or delaying surgical correction.
  110. 110. “In the field of scientific observation, chance favours the prepared mind” Dr. Louis Pasteur Thank you