Presentation1, abdominal ultrasound anatomy.

Health&medicine

1. Dr/ ABD ALLAH NAZEER. MD. Abdominal Ultrasound Anatomy.

2. LIVER The liver is the largest one organ in the abdomen. It varies considerably in size and configuration from individual to individual. Ultrasound provides an excellent means of assessing internal structures of the liver and evaluating both diffuse and focal parenchymal abnormalities. Familiarity with the internal hepatic anatomy is important in order to diagnose disease . COUINAUD'S ANATOMY Couinaud Anatomy is becoming the universal nomenclature for hepatic lesion localization. This description is based on portal segments and is of both functional and pathologic importance. Each segment has its own blood supply including arterial, portal, hepatic venous and biliary drainage. There are eight segments. Segment I is the caudate lobe, II and III are the left superior and inferior lateral segments respectively. Segment IV is the medial segment of the left lobe and further divided into IVa and IVb. The right lobe consists of four segments. Segment V and VI are the inferior anterior and posterior segments respectively. Segment VII is the superior posterior segment and segment VIII is the superior anterior one.

3. Things to look: 1. Position: It is usually 15 to 17cm in length with its upper border usually at the level of the nipples and its lower border at the level of the costal cartilage of the 8-9th rib . 2.SIZE  Normally, the adult liver weighs from 1400 to 1600gm with the right lobe six times larger than the left.   3. SHAPE + OUTLINE Wedged shape with smooth outline  4. BRIGHTNESS  Pancreas > Liver > Spleen > Kidneys   5. TESTURE  Homogenous and fine echopattern. Scanning Technique   1 . Longitudinal scan from the outer margin of the left lobe to the outer margin of the right lobe.   2. Transverse scan with the probe angled cephalic to include the superior margin to the inferior margin of the left and right lobe of the liver.    3. Subcostal scan to examine the whole of the right lobe.   4. Intercostal scan which is a supplementary view for examining the right lobe of the liver especially when the right lobe is well within the rib cage.

4. PROBE POSITIONING TO SCAN THE LIVER. Rt. Lobe Liver. Parasagittal Scan Plane The Liver and Rt. Kidney are visualized in this view.

5. Intercostal Scan Plane. The Middle and Rt. Hepatic Vein are visualized in this view.

6. Subcostal Scan Plane. The probe is angled cephalad under the ribs to avoid any bowel or ribs shadowing over the liver. Rt. Portal Vein is shown coursing transversely in this view.

7. Left Lobe Of Liver   Scan Plane Left Lobe of Liver. The probe is in the epigastric region just below the sternum. It is angled cephalad to view the left lobe in its entirety. The probe may need to be angled towards the left side to see the most medial edge of the left lobe. Normal Anatomy seen in the Transverse View of the Left Lobe.

8. The Portal Vein should have constant forward flow into the liver (hepatopetal flow) .As seen in this image, the color is red ,which is set for movement towards the probe. Be very careful to make sure you look at the color box on the side of the image to know the setting. Because the hepatic veins drain into the IVC immediately prior to the Right Atrium, they have phasic flow reflective of cardiac motion. 

9. Para-sagittal Left. Sagittal Midline. The Ligamentum venosum is highlighted in orange. lhv : Left hepatic vein  IVC: Inferior vena cava ULTRASOUND OF LIVER SEGMENTS

10. Para-sagittal Mid-clavicular . RPV: Right Portal Vein RHV: Right hepatic vein Para-sagittal Right

11. Porta hepatis is seen with an oblique angle 45degree rotation from the sagittal view to the transverse view. Oblique left showing the ligamentum teres.

12. Transverse Plane showing the Ligamentum Venosum. Transverse Superior Left lhv: left hepatic vein  mhv: middle hepatic vein

13. Transverse Mid Right rpv : right portal vein  lpv : left portal vein Transverse Superior Right.

14. MIDCLAVICULAR, If the measurement is made from the ant diaphragm to the lower edge of the liver in the mid-clavicular line  it should be no >13cm  MIDHEPATIC, Measured in the mid hepatic line with a large field of view it should measure <16cm from the post diaphragm to the lower anterior edge . 

15. Gall ladder & Biliary Tract: The examination begin with the patient in supine position. Once supine view is obtained, the patient is positioned in the oblique (both right and left sides up), decubitus views or sometimes in upright position so that optimal visualization can be obtained and to determine that stones roll to the dependent portion of the gall bladder . Transverse , longitudinal and oblique views with the transducer are always performed . PANCREAS   • All vascular landmarks and adjacent structures must be identified in two planes • When bowel gas obscures visualization, we ask the patient to drink water and use the stomach as a window . • All patient position must be utilized, obliques, decubitus and upright when necessary.

16. ULTRASOUND OF THE GALLBLADDER – Normal. Normal Scanning Position to take advantage of using the liver as a window and displacing the bowel. A normal Gallbladder should be thin walled (<3mm) and anechoic . It is a pear shaped saccular structure for bile storage in the Right Upper Quadrant. Its size varies depending on the amount of bile. Fasted it will be approximately 10cm long.

17. Folds are commonly seen and are normal. Make note if pathology such as calculi are contained within a compartment created by a fold.

18. A  Phrygian cap  is a specific, relatively common , inversion of the distal fundus of the gallbladder into the body . It may become adherent. It is an anatomic variant or acquired abnormality.

19. ULTRASOUND OF THE PANCREAS - Normal Pancreas Scan Plane. Normal Pancreas and surrounding anatomy.

20. Sagittal Scan Plane Pancreatic Head Head of pancreas.

21. Fatty infiltration of the pancreas with focal sparing of the uncinate process.

22. You can see no mass effect or compression of the CBD. A progress u/s to confirm or, if in doubt, a double contrast CT can help confirm this finding.

23. ULTRASOUND OF THE SPLEEN – Normal. Intercostal scan plane. Normal Spleen. Use the lower left intercostal spaces. Patient in right lateral decubitus (right side down ). Examined either obliquely or longitudinally in coronal plane.

24. The size of the spleen can be extremely variable ranging from 7cm- 14cm. Accesory spleens or splenunculi are common . ( singular = splenunculus ).

25. ULTRASOUND FOR ABDOMINAL AORTA. Normal Transverse B Mode Aorta. AP and Transverse Diameter should be < 3cm. Abdominal Aortic Aneurysm distance   to the renal arteries. Any atherosclerosis should be noted.

26. URINARY TRACT. • Right kidney is best seen with the patient in the supine position using the liver as an acoustic window. • With suspended respiration, scanning can be performed either subcostally or intercostally. Sagittal and transverse views of the kidneys should be obtained • Left kidney is best seen in the right lateral decubitus position ( left side up) using a coronal axis. When possible, the spleen should be used as an acoustic window. Deep inspiration is recommended • Urinary bladder has to well distended in order to give good visualization . Transverse and longitudinal scan planes are used to determine any lesion or wall-thickening. Sometimes decubitus position has to be used for differentiate between bladder wall lesion or stones .

27. ULTRASOUND OF THE ADULT KIDNEY - Normal Coronal scan plane for the Right Kidney. Longitudinal: Normal Kidney.

28. Scan plane transverse kidney Transverse normal image

29. ULTRASOUND OF THE BLADDER - Normal Longitudinal Bladder View. Longitudinal Bladder Image

30. Transverse Scan Plane Transverse Bladder Image

31. ULTRASOUND OF THE PROSTATE - Normal Angle the probe caudally and in the  midline to get a sagittal view of the prostate. Prostate is situated behind the bladder.

32. Transverse View Prostate Turn the probe 90degrees and angle caudally to get the transverse view.

33. NORMAL PROSTATE IMAGES TRANSRECTAL (TRUS) Axial Image Prostate Volume

34. ULTRASOUND OF THE UTERUS - Normal Uterus TA probe positioning for longitudinal scan. Uterus sagittal US image.

35. Uterus TA probe positioning for transverse scan.  Trans abdominal view of the uterus: transverse. Both ovaries are visible

36. Transvaginal Technique Anteverted uterus. Normal TV image anteverted sagittal.

37. Retroverted uterus transvaginal scan. Retroverted transvaginal technique hl.

38. The probe is turned slowly anticlockwise to visualise the uterus at 90degrees to the sagittal view . The Maximum Width is measured in this transverse (coronal) plane.

39. ULTRASOUND OF THE OVARIES - Normal Use the full urinary bladder as an acoustic window to angle across to the ovary. Axial trans-abdominal image with the ovary lateral to the uterus.

40. Axial trans-vaginal scan plane. Axial trans-vaginal image.

41. Normal transvaginal ovary demonstration normal peripheral follicles. The uterus may be oblique and squash the ovary giving it a flattened ovoid shape.

42. ULTRASOUND OF THE APPENDIX - Normal Refer to this study which concluded that the location of the appendix has wide individual variability , and the limitations of McBurney's point as an anatomic landmark should be recognized. The appendix can be found from the groin, to the umbilicus or even higher under the liver. It is rarely midline or in the left iliac fossa.

43. Appendicitis can be diagnosed when the outer diameter of the appendix measures greater than 6mm. Normal Appendix

44. This image high lights the position of the caecum and the appendix ( mouseover )

45. Ultrasound of the Gastrointestinal Tract. Normal Gut Signature. The normal bowel usually has a 3-layer appearance with an echogenic inner layer of mucosa and submucosa, a hypoechoic middle layer of muscle wall, and a thin echogenic outer layer of serosa. Contents of the gut lumen are variable in appearance. A. The gastric antrum (arrow) is commonly visualized as it crosses anterior to the pancreas (p). B. The gastric antrum in another patient is distended with mixed echogenicity fluid and shows echogenic mucosal folds (long arrow). The distended bowel has a thinner hypoechoic muscle zone (short arrow).

46. Typical Keyboard Pattern of Jejunal Folds. A fluid distended loop of jejunum (SB) shows the folds of the valvulae conniventes as a row of echogenic “piano keys” (arrows) extending from its wall.

47. Thank You.