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Abdomen Scan Protocol Clinical Application Team All information in the presentation are highly confidential and no part of contents may be informed or transmitted without permission from ALPINION Medical Systems. Abdomen Scan Protocol 1. Longitudinal scan 2. Transverse scan 3. Rt. Subcostal scan 4. Rt. Hypochondriac oblique 5. Rt. Intercostal scan 6. Rt. Coronal scan in mid-axillary line 8. Lt. Coronal scan in mid-axillary line Liver Consists of 4 lobes ; The left, right, caudate, and quadrate lobes. The left and right lobes are separated by the falciform ligament. The small caudate lobe is the separate lobe between the IVC and the Ligamentum venosum The small quadrate lobe is inferior to the caudate lobe and porta hepatis. Ligamentum teres (obliterated left umbilical vein) is the free edge of the falciform ligament Liver - Couinaud’s 8 Segments • • • • • • S1 Caudate lobe S2 Lateral superior segment of LT S3 Lateral inferior segment of LT S4 Medial segment of LT S5 Anterior inferior segment of RT S6 Posterior inferior segment of RT S7 Posterior superior segment of RT S8 Anterior superior segment of RT Hepatic vein ; inter-segmental Main hepatic vein divides into the right/left lobes Right hepatic vein divides the RT lobe into the anterior/posterior segments Left hepatic vein divides the LT lobe into the medial/lateral segments Portal vein ; intra-segmental Main portal vein divides into RPV and LPV at liver hilum Right portal vein (RPV) divides into anterior and posterior parts Left portal vein (LPV) proceeds cranially along the left lobe then abruptly turns anteriorly Hepatic vein vs. Portal vein Hepatic veins Portal veins Between the hepatic lobes → inter-segmental Within the lobar segments → intra-segmental The diameter becomes greater toward the diaphragm The diameter is greater to the porta hepatis Border act as specular reflectors → not echogenic unless beam angles is 90 degree Highly echogenic boundaries Main hepatic artery Right hepatic artery Left hepatic artery Main portal vein Right portal vein Left portal vein (transverse & umbilical portion) Liver scan protocol 1) Longitudinal scan 2) Transverse scan 2) Subcostal scan - Scan under the right ribs 3) Intercostal scan - Scan between the ribs Longitudinal scan – Abdominal aorta 1) Place the probe on the mid-sagittal line right below the Xiphoid 2) Tilt the probe to the left 3) AA (Abdominal aorta) diameter measurement 4) Check the calcification or plaque in aorta (Zoom) Pancreas Celiac axis Portal vein SMA Aorta Celiac trunk and SMA from Abdominal aorta Diaphragm located superiorly (left), pancreas located inferiorly (right) Normal AA diameter is about 3cm Longitudinal scan – Left lobe 1) 2) 3) 4) Place the probe on the mid-sagittal line right below the Xiphoid Tilt the probe to the Right Check the Lt lobe margin and S1(Caudate lobe) Check the IVC dilatation IVC continues to the right atrium superiorly (left) At the same level, the hepatic veins can be seen Hypertrophy of the caudate lobe is seen in Budd-Chiari syndrome(caused by occlusion of hepatic venous outflow) or Cirrhosis RA Subcostal scan – Portal vein 1) 2) 3) 4) Place the probe under the right rib margin Ask patient to take a deep breath and hold it Sweep the probe to examine the whole of segmental lobe IHD (Intrahepatic bile duct) measurement if it is dilatated The bifurcation of RPV and LPV The bifurcation of RPV and LPV (echogenic wall) S2 to S7 can be seen if you scan the umbilical portion of LPV LPV has the pars transversa and the umbilical (ascending) portion Normal IHD diameter < 2mm Subcostal scan – Left lobe 1) Place the probe right under the right rib margin 2) Ask patient to take a deep breath and hold it 3) Scan the umbilical portion of LPV and its branches Umbilical portion of LPV S3 S4 S2 Ligament venosum IVC LPV turns abruptly anteriorly after transverse portion; Umbilical portion Umbilical portion of LPV and its branches form a “Recumbent H” sign Caudate lobe is located between ligament venosum and IVC Subcostal scan – Hepatic vein 1) Place the probe under the right rib margin 2) Tilt the probe with cephalic angulation 3) Ask patient to take a deep breath and hold it The hepatic veins have non-echogenic walls Size is changed as patients breathes MHV separates Rt. lobe and Lt. lobe RHV separates Anterior segment(S5, S8), Posterior segment(S6, S7) LHV separates Superior segments(S2) and Inferior segments(S3) Intercostal scan – Right lobe 1) Place the probe between the right ribs 2) Ask patient to breathe out and hold it 3) Move transducer to next intercostal space & scan through RPV IVC Visualize RHV & RPV in right lobe in detail Segment 7~8 External CBD and hepatic Artery Pancreas Location - Between the duodenal loop and the splenic hilum. - The stomach and duodenum lies anterior to the pancreas. Role of Pancreas - After food enters the duodenum, the exocrine tissues secrete a digestive juice that break down food into small molecules - The endocrine tissue(islets of Langerhans) secretes hormones(Insulin, Glucagon) directly into the bloodstream. Anatomic structure - Divided into a head, uncinate process, neck, body, tail. - Uncinate process is posterior to the SMA, SMV. - Pancreatic duct is parallel to the skin surface and its wall Common Pathology - Adenocarcinoma - Pseudocyst - Pancreatitis - Fatty change - Insulinomas - Cystic fibrosis Pancreas scan protocol 1) Longitudinal scan 2) Transverse scan 3) Oblique Transverse scan - For scanning pancreatic tail Transverse scan - Pancreas 1) Place the probe on the Xiphoid process with slightly caudal angulation 2) Apply enough pressure to help displace bowel gas 3) Scan from the head to the tail of pancreas in detail Head (Uncinate process) – Tilt the probe to the left Tail – Tilt the probe to the right 4) Use the splenic vein to help identify the pancreatic body 5) Measure the diameter of PD (Pancreatic duct) Hyperechoic than liver (because of fatty infiltration) Splenic vein always runs along posterior border of pancreas The pancreatic head surrounds the portal vein Normal pancreatic duct : 1~2mm GB (Gallbladder) Role of GB - Common bile ducts carry bile from the liver to the duodenum where it helps to digest the fatty foods. - The gall bladder stores this bile in between meals. Common Bile Duct - Common hepatic duct + Cystic duct - A part of portal triad with portal vein and hepatic artery under surface of the liver Sonographic appearance - A normal GB should be thin walled (<3mm) and anechoic. - Size varies depending on the amount of bile. - Fasted, it will be approximately 10cm long. Common Pathology - Folds/Phrygian cap - Polyp - Calculi/Sludge - Cholecystitis - Adenomyomatosis - Gallbladder Carcinoma GB Scan Protocol 1) 2) 3) The location of GB is variable case by case Subcostal scan Intercostal scan Perpendicular to subcostal margin. GB scan – Long Axis view (Subcostal scan) 1) 2) 3) 4) 5) 6) Supine or left lateral decubitus position (Better) Ask the patient to take a deep breath and hold it (Deep inspiration will move the GB below the ribs for easier access) Visualize the longest length of GB Check internal lesion (polyp or calcification) in detail Check GB wall thickening or phrygian cap Measure the wall thickness of GB Normal thickness of GB wall<3mm Sometimes there is a phrygian cap Wall thickening disease : hepatis, ascites, hypoalbuminemia renal disease, multiple myeloma Subcostal margin GB scan – Long Axis view (Subcostal scan) 1) 2) Supine or left lateral decubitus position (Better) Ask the patient to take a deep breath and hold it (Deep inspiration will move the GB below the ribs for easier access) 3) Visualize the CBD (Common bile duct) on B/CF mode to distinguish with portal vein 4) Measure the thickness of CBD Normal CBD diameter < 6mm Proximal CBD runs along the main portal vein superiorly CBD enters to the liver hilum with hepatic artery and portal vein Spleen Location - In the upper far left part of the abdomen, to the left of the stomach - Protected by the rib cage, you can’t easily feel it unless it’s abnormally enlarged Role of Pancreas - Acts as a filter for blood as part of the immune system. - Old red blood cells are recycled in the spleen, and platelets and white blood cells are stored there. - Helps fight certain kinds of bacteria that cause pneumonia and meningitis. Anatomic structure - Commonly fist-shaped, purple, and about 4 inches long Common Pathology - Splenomegaly >12-14 cm and becomes rounded. - Infection- multiple echogenic foci (granulomata) - Hemangioma - Lymphoma - Varices - portal hypertension - Hematomas - Abscess - Splenic infarction Spleen scan protocol 1) Lt. longitudinal scan 2) Transverse scan with pancreatic tail Spleen scan – Longitudinal scan 1) Supine or Right lateral decubitus position 2) Place the probe on the right mid-sagittal line obliquely 3) Overlying bowel and lung gas or rib shadows can cause problems 4) Measure the major axis of spleen when hilum is seen (In case of having a liver disease, make sure to measure the size) Spleen Splenic vein of hilum -Homogeneous and less echogenic than liver - Normal size of spleen : <12cm (or Volume <400/500cc) - Splenomegaly : >12cm - Considered enlarged if it covers the entire left kidney - Pancreatic tail inserts to the spleen Kidney Location - the back of the abdominal cavity (retroperitoneal organs), just above the waist - The liver is located just above the right kidney - The spleen is located just above the left kidney - The right kidney is usually slightly lower than the left. (liver) Role of Kidney - The removal of toxic waste products from the body - Regulate blood pressure and the production of certain hormones - homeostasis and maintaining general good health. Internal Anatomic structure - Renal cortex : a light outer area - Renal columns : The areas between the pyramids. - Renal medulla : a darker inner area - Renal pyramids : Within the medulla, cone-shaped sections - Renal papilla : the smaller end of the renal pyramids. - Minor calyx : a cup which collects urine for removal from the kidney. merge into a Major calyx. - Renal Pelvis : the exit of the kidney connected the ureter Kidney - Normal Appearance • Echogenecity - Kidney is surrounded with a capsule which is a thick fiber structure (strong interface) - Renal cortex is less echogenic than the normal liver and spleen (consists of nephron) - Medulla Pyramids look anechoic (contain fluid, which is urine). - Renal pelvis (renal sinus) is filled with urine and echo free • Normal size - length : 10~12cm - width : 4~6cm - Cortical thickness (not<10mm) Kidney scan protocol 1) Longitudinal scan 2) Transverse scan Kidney scan – Longitudinal (Coronal) scan 1) 2) 3) 4) 5) 6) Place the probe on the mid-axillary lines in the supine position Slightly rotate the probe in oblique direction Right kidney – Use liver for acoustic window Left kidney – Use spleen for acoustic window With deep inspiration, hold it Measure the size for checking chronic renal failure Cortex is less echogenic than liver Central echoes from fat surrounding renal pelvis are white Medulla and renal pelvis are hypoechoic since it is filled with urine Spleen Morison’s pouch Splenorenal recess Right kidney Left kidney Kidney scan – Color/Power Doppler Renal pathologies affecting renal hemodynamics Renal artery stenosis and occlusion Renal vein thrombosis Aneurysm and pseudoaneurysm Pyelonephritis Kidney – Abnormal Appearance • Hydronephrosis - The swelling of a kidney due to a build-up of urine. - It happens when urine cannot drain out from the kidney (renal pelvis) to the bladder from a blockage or obstruction and it cause the renal pelvis to be enlarged. Mild hydronephrosis Moderate hydronephrosis Severe hydronephrosis Kidney – Abnormal Appearance • Renal calculi (Kidney stone) - Bright hyperechoic oval/round structures within the cortex or renal sinus - Makes the posterior shadowing behind the kidney stone • Renal cyst - Anechoic structure often at the periphery of the renal cortex with a thin wall, and posterior acoustic enhancement. - Cysts are typically single and arise in the periphery of the kidney, but can be multiple as in polycystic kidney disease. Kidney – Abnormal Appearance • Ectopic Kidney - A birth defect in which a kidney is located below, above, or on the opposite side of its usual position - The most common ectopic site is in the pelvis - The crossed-ectopic kidney : a single large fused kidney : Cross fused ectopic kidney. The left kidney is fused to the lower pole of the right kidney Artifacts • Mirror image artifacts : a lesion located near a large specular surface (metastatic liver next to diaphragm) may result in a false lesion above the diaphragm. : beam is reflected by the diaphragm and redirected into the liver before transducer. • Reverberation Artifact : At strong interfaces, the returning echo is reflected back into the tissue. : at large superficial parallel specular reflectors (such as the urinary bladder) • Shadowing : an absence of echoes posterior to highly reflective structures (stone, bone..) • Acoustic enhancement : a band of increased echoes distal to a low attenuating structure (liver cyst) Mirror image artifacts Shadowing Acoustic enhancement Artifacts • Comet-Tail Artifact : short range(internal) reverberation. : Most often caused by small metallic objects : Bright lines forming a relatively short linear stream of echoes • Ringdown Artifact : resonance phenomenon in a pocket of air bubbles in a fluid medium (in the stomach and duodenum) : Appears as a long linear, stream of echoes. : Caused by air bubbles → can diagnosis pneumobilia or abscess : Can reduce by decreasing overall gain or TGC in near field • Tissue Velocity Change Artifact : The machine is calibrated for average soft tissue velocities of 1540m/s. : Tissue with a slower velocity (fat) is placed at a greater distance from the transducer. Comet-Tail artifact Ringdown artifact Velocity Change artifact Thank You All information in the presentation are highly confidential and no part of contents may be informed or transmitted without permission from ALPINION Medical Systems.
