ANATOMY OF KIDNEY.pptx

ANATOMY OF KIDNEY

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.

3. 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.

4. 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 .

5. 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.

6. 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.

7. BLOOD SUPPLY OF KIDNEY

8. 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.

9. USG IMAGE OF NORMAL KIDNEY

10. 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

11. 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 .

12. 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.

13. 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. One kidney is enlarged or more lobulated than normal The commonest cause of an enlarged kidney is hydronephrosis, which will appear on ultrasound images as multiple, well circumscribed cystic areas (the calyces) with a dilated central cystic area (the renal pelvis, normally less than 1 cm

14. 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. MILD -If pelvis is wider than 1cm and there is nocalyceal dilation. Moderate -There is calyceal dilation. Severe -There is loss of renal cortex.

15. TYPES OF HYDRONEPHROSIS

16. 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.

17. SIMPLE CYST IN RIGHT KIDNEY

18. 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.

19. IMAGE OF RENAL MASS

20. 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.

21. 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

22. USG IMAGE OF RENAL STONE

23. 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 Abdominal ureter-from renal pelvis to the pelvic brim. Pelvic ureter-from pelvic brim to the bladder. Intravesical or Intramural ureter-within in the bladder wall.

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

25. CONSTRICTIONS OF URETER

26. 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

27. 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.

28. 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.

29. 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 .

30. VARIANT ANATOMY cont . Septation Agenesis Ureterocele -dilation of the intravesical part of the ureter. USG INDICATIONS OF URINARY BLADDER Dysuria or frequency of micturation Haematuria Recurrent infection(cystitis) Pelvis mass Retention of urine Pelvic pain

31. 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.

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

33. 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 Attached to the wall Polyp-appear freely mobile on a long stalk. Adherent calculus

34. HAEMATOMA IN BLADDER

35. POLYP IN BLADDER

36. 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

37. URETEROCELE IN BLADDER

38. CALCULUS IN BLADDER

39. LARGE(OVERDISTENDED)BLADDER Common causes Enlargement of prostate Uretheral stricture in male Urethal calculus in male Bruising of the urethera I female( honeymone urethritis) Neurogenic bladder Uretheral valves SMALL BLADDER Recurrent cystitis Radiotherpy or surgery for malignancy

40. 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.

41. ZONAL ANATOMY Three distinct zones- 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.

42. 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.

43. BLOOD SUPPLY 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 Absence of middle lobe Presence of a 4 th lobe

44. PATHOLOGY 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

45. USG IMAGE OF BHP

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