Renal us 2017

Renal us 2017

1. RENAL ULTRASOUND
By
Mohamed Abou El-Ghar

2. Objectives
•Normal anatomy
•Approach to performing the US study
•Abnormal findings
•Clinical impact

3. Performing the Study
•Patient preparation:
–none
•Transducer: 3.0MHz or 3.5 MHz
–5.0 MHz for thin patient
•Patient positioning
–Supine
–Posterior oblique, lateral decubitus, prone

4. Anatomy
•Kidneys are retroperitoneal
•Right kidney is lower than the left kidney
•Right kidney is postero-inferior to liver &
gallbladder
•Left kidney is inferior-medial to the spleen
•Adrenal glands are superior, anterior, medial
to each kidney

5. Celiac
axis
SMA
Renal artery
Renal vein
Hepatic
Veins
Right
kidney
Left
kidney
Liver
Spleen

6. Renal Scanning Approaches

7. Approach to Scanning
•Right kidney scanning
approach: anterior,
lateral, posterior
•Liver is the acoustic
window
•Left kidney: requires a posterior
approach, through the spleen
•Air-filled bowel impedes
anterior scanning
I
LIVER STOMACH
IVC
AORTA
K K
S

8. Anatomy
•9-12 cm long, 4-5 cm wide, 3-4 cm thick
•Gerota’s fascia encloses kidney, capsule,
perinephric fat
•Sinus
–Hilum: vessels, nerves, lymphatics, ureter
–Pelvis: major and minor calyces
•Parenchyma surrounds the sinus
–Cortex: site of urine formation, contains nephrons
–Medulla: contains pyramids that pass urine to minor
calyces. Columns of Bertin separate pyramids

9. Renal capsule
Cortex
Medullary pyramids
Minor
Calyx
Kidney
Anatomy
Medulla
Sinus
Major
Calyx

10. Sonographic Appearance
•Ureters are normally not seen
•Renal pelvis is black when visible
•Renal sinus is echogenic due to fat
•Medullary pyramids are hypoechoic
•Cortex is mid-gray, less echogenic than liver or
spleen.
•Capsule is smooth and echogenic

11. Right Kidney Long Axis

12. Liver
Diaphragm
Sinus
Cortex
Anterior
Posterior
Superior Inferior
Right Kidney Long Axis

13. Right Kidney Transverse Axis

14. Right Kidney Transverse Axis
Vertebral
Body
R Kidney
Aorta
Renal a.
GB
IVC
Liver
Anterior
Posterior
Right Left

15. Left Kidney Long Axis

16. Left Kidney Long Axis
Anterior
Posterior
Superior
Inferior
Spleen
Kidney
Rib
Shadow

17. Left Kidney Transverse Axis

18. Left Kidney Short Axis
Anterior
Posterior
Right Left
Liver
Spleen
L Kidney

19. Common Pitfalls in
Renal Scanning
•Failure to scan both kidneys
•Mistaking prominent renal pyramids for
hydronephrosis
•Mistaking prominent pyramids for cysts
•Confusing normal renal arteries for the
ureter

20. Common Pitfalls in
Renal Scanning

•Failure to scan through the bladder to
search for stone at the uretero-vesicular
junction
•Inability to visualize left kidney due to
anterior probe placement
•Failure to scan the aorta in suspected renal
colic

22. Normal Variants
•Dromedary humps:
–Lateral kidney bulge, same echogenicity as the cortex
•Hypertrophied column of Bertin:
–Cortical tissue indents the renal sinus
•Double collecting system:
–Sinus divided by a hypertrophied column of Bertin
•Horseshoe kidney:
–Kidneys are connected, usually at the lower pole
•Renal ectopia:
–One or both kidneys outside the normal renal fossa

23. PERSISTENT FOETAL LOBULATION

24. Hypertrophied column of Bertin

25. ECTOPIC KIDNEY

26. HORSESHOE KIDNEY

27. Renal Duplex

28. Clinical Indications
- Obstructive Uropathy
- Renal cyst
- Renal mass carcinoma
- Renal parenchyma disease

29. Nephrolithiasis

•Look for bright objects that cast a
shadow within the kidney.
•If you can, follow the dilated ureter down
toward the bladder.
•It is often difficult to identify ureteral
stones.

33. Hydronephrosis

Dilatation of the urinary tract at any level
secondary to intrinsic and or extrinsic
obstruction to urine flow

34. Hydronephrosis

•Dilated anechoic calyses with increased
posterior transmission of sound.
•Hyperechoic fat delineating dilated calyces.
•Cortex is normal with similar echo pattern of
liver.
•Kidneys in obstructive renal disease show
hydronephrosis.

35. Hydronephrosis
•Intrinsic, acquired
–Renal lithiasis
–Neoplasm (renal, ureteral, bladder)
–Papillary necrosis
–Ureterocele
–Blood clot
–Neurogenic bladder
–Anticholinergics
–Pregnancy, PID, uterine prolapse)
–Diuretics
–Vesico-ureteral reflux
–Diabetes insipidus
•Intrinsic, congenital
–Stenosis (ureteral,
urethral, meatal)
–Adynamic ureter
–Spinal cord defects
–Duplication of the
ureter
–Ureterocele

36. Obstructive Uropathy
Grading System - Subjective
•Mild
–Minimal separation of calyces
•Moderate
–Dilation of major and minor calyceal system
•Severe
–Marked dilation of the renal pelvis and thinning of
the renal parenchyma

37. Range of Hydronephrosis
Normal
Mild
Moderate Severe

38. Mild Hydronephrosis
Kidney Liver
GB

39. Moderate - Severe
Hydronephrosis
Liver
Kidney
Dilated pelvis
GB

41. Renal Cysts
•Arise in the renal cortex, commonly single rather
than multiple
•Cysts do not communicate; hydronephrosis does
•Shape is round or oval
•Echo free
•Sharp interface between the mass and renal
tissue
•Large renal cysts may be mistaken for aortic
aneurysms

42. Renal Cysts
Liver
Kidney
Cyst

43. Renal Cysts

44. Complex Renal Cyst

•Cysts where the inner lining is irregular, with
septations and fluid has echoes are
considered complex cysts.
•Complex cysts require additional further work-
up to rule out cavitating cancer or renal
abscess.
•Anechoic mass. Some irregularities are seen
along the inner lining.

46. Polycystic kidney

47. Mimics

48. Renal Masses
•Ultrasound visualizes most solid and cystic renal
masses
•Appearance
–Irregular borders
–Poorly defined interfaces between mass and kidney
•Complex masses
–Complex ultrasonic appearance
–Cysts or solid masses may represent infection or
hemorrhage
–May have fluid levels

49. Renal cell carcinoma

51. Chronic renal failure (Medical
Kidney)
•Kidneys are smaller than normal.
•Surface may be irregular.
•Cortex is thinned and is hyperechoic than liver
due to scar tissue.
•Kidneys are small, irregular and hyperechoic
in chronic renal failure due to medical renal
disease.

53. CRHONIC RENAL FAILURE

54. Transplant kidney

55. Pearls & Pitfalls
•Renal cysts can sometimes be mistaken for
hydronephrosis. Cysts are typically single and
arise in the periphery of the kidney, but can be
multiple as in polycystic kidney disease.
•A collecting system located outside the kidney
is termed extrarenal pelvis. This can mimic
early hydronephrosis but is a normal
developmental variant.

56. Pearls & Pitfalls
•The overhydrated patient may have mild
hydronephrosis without obstruction. In this
case, both kidneys will show evidence of mild
hydronephrosis
•The underhydrated patient may not have
hydronephrosis on initial renal scanning,
despite the presence of obstruction and renal
colic

57. THANK YOU