Basic Abdominal Ultrasound Exam Flashcards
WAVE Soft Tissue Level 1 lesson 5
Basic Abdominal Ultrasound Includes…
Liver, Gallbladder, Spleen, Kidneys, Urinary Bladder
Liver Lobes
4 lobes, 4 sublobes, 2 processes. Left lobe(left lateral, medial) Quadrate, Right Lobe(Medial, lateral) Caudate(caudate process, papillary process).
Portal Veins
Hyperechoic walls(fibrofatty tissue)
Hepatic Arteries
Difficult to visualize, may be identified near the portal hepatis - use doppler to differentiate from portal veins and common bile duct.
Hepatic Veins
Lack hyperechoic walls and can be traced to the caudal vena cava.
Liver Approach
Subcostal and intercostal
Liver size
Subjective assessment, consider breed and confirmation. Radiograph can provide better estimation of normal vs abnormal.
Liver Appearance on US
Uniform, coarser, and less echogenic than spleen, similar of slightley greater echogenicity than right kidneyy. Smooth, sharp margins.
Gallbladder
Round to oval anechoic structure with distal acoustic enhancement.
Gallbladder Appearance
Walls may or may not be visible. Size variable depending on last meal. Cats may be bilobed.
Gallbladder Wall - Cats
Cats less than 1 mm(usually 0.4 mm), anything greater is indicative of disease. Less than 1 mm cannot rule out presence of mild chronic inflammation.
Gallbladder Wall - Dogs
2-3 mm
Biliary Tract
Intrahepatic ducts not typically seen in normal patients. Common Bile Duct(CBD) often difficult to see due to bowel gas.
Common Bile Duct
Tubular Structure with thin echogenic Walls with no doppler signal(differentiate from hepatic vessels).
CBD Dogs
Normal is 3mm in diameter
CBD Cats
Normal is 4 mm in diameter. Greater or equal to 5 mm is suggestive of post hepatic obstruction.
Liver Scanning Planes
6 sagittal views
Left lateral Left lateral, toward midline
Midline
Gallbladder Right lateral, toward
midline
Gallbladder Right lateral, cranial Right lateral, caudal
(caudate)
4 transverse views (may need
to image right and left sides
separately)
▪ Cranial
▪ Mid
▪ Caudal
Spleen Anatomy
Head(dorsal extremity), Body(vascular Hilus), Tail
Spleen Landmarks
Position dependent on stomach distension and size of other abdominal organs. Located in left lateral abdomen, caudal to the liver and stomach, vental/lateral to the left kidnet. Head extends cranially and laterally to 12 rib space.
Gastrosplenic Ligament
Where head of spleen attaches to stomach.
Spleen dog vs cat
Dog- head attatches to stomach then crosses midline ventrally
Cat- head attatches to stomach then runs along the left body wall.
Spleen Size
Subjective, effected by some sedatives.
Dog ~2.5 cm or less mid-body level.
Cats 1 cm or less mid-body level.
Spleen Shape
Elongated with smooth Echogenic capsule. Head is fixed, body can be anywhere.
Spleen Echogenicity
Uniform, smooth, homogoneous and hyperechoic to liver or renal cortex/medulla.
Splenic Vasculature
Veins, no defined walls, arteries not seen.
Spleen Scan Plans
▪ 4 SAGITTAL/4 TRANSVERSE VIEWS
▪ SPLENIC HEAD (DORSAL SPLEEN)
▪ CRANIAL BODY
▪ MID-BODY (HILUS)
▪ TAIL
▪ COMPARISON VIEW OF LIVER VS. SPLEEN
Left Kidney Landmarks
Left lateral retroperitoneal space, use 13th rib as landmark, dorsal/medial to the spleen.
Right Kidney Landmarks
Right lateral retroperitoneal space, tucked under ribcage in dogs, use 13th rib as landmark, caudate lobe of liver(renal fossa)
Renal Anatomy
Hypoechoic to spleen, iso to hypoechoic to liver. Medulla Hypoechoic to cortex. Distinct corticomedullary junction. Pelvis and diverticulae(collecting system) not usually visible, fat within the renal sinus may shadow like mineralization.
Kidney Size/Shape
Dogs vary in size, bean shaped.
Cats ~3-5 cm, more rounded, more mobile and can be pushed away by transducer. Symmetry important.
Collecting System(Renal)
Pelvis and ureter typically not seen, if visualized normal diameter is less than 2 mm. Diuresis may lead to mild renal pelvic dilation. Evaluate for calculi/mineralization.
Renal Vasculature
Artery and vein enter at hilus. Vein ventral to artery.
Renal Capsule
Smooth, Hyperechoic
Kidney Echogenicity
Cortex hypoechoic to spleen, iso-hypoechoic to liver.
Medulla is hypoechoic to cortex.
Distinct cortico-medullary junction.
Kidney Scan Planes
▪ 4 SAGITTAL VIEWS
▪ MEDIAL
▪ MEDIAL W/PELVIS
▪ MID (W/ AND W/O
MEASUREMENT)
▪ LATERAL
* 3 TRANSVERSE VIEWS (SLIDE)
* CRANIAL
* MID
* CAUDAL
* COMPARE KIDNEY VS. LIVER
(ONE OR BOTH KIDNEYS)
Differences of Right vs Left Kidney
Dogs- Right cranial and intimate with renal fossa of caudate lover lobe. Deepchested dogs may be difficult and subcostal view may be off, intercostal view can clean up the image.
Urinary Bladder Wall
Wall will apppear as thin hyperechoic line. May see layers- Hyperechoic outer serosal, hypoechoic muscularis layer, hyperechoic submucosa/mucosa.
Bladder Wall Thickness
Varies with distension.
Dogs- 2.3 mm in minimal distended, 1.4 in moderately distended
Cats- 1.3 to 1.7 mm is normal
Small protuberances at dorsocaudal trigone or ureter openings.
Bladder Landmarks
Caudal abdomen, mid-line. Blood vessels and lymph nodes dorsal, colon dorsal or dorsolaterally.
Urinary Bladder Scan Planes
3 Sagital
-Lateral to right
-mid/trigone
-lateral to left
3 Transverse
-cranial
-mid
-caudal(trigone)
What to include for Teleradiology Consult(Basic/Beginners)
Sag/Trans of every normal organ with annotations.
-Liver: atleast sag/trans of left, central, and right liver and caudate lobe/R kidney junction.
-GB: Sag/trans. Treat as own site
-Spleen: Sag/trans of head, body and tail. If possible comparison view of it with liver and with L kidney
-Kidneys- Sag(with and without measurements) and transverse of each kidney
-Urinary Bladder- # of images submitted depends on distension. Sag/Trasn of apex, body and trigone.
What to include for Teleradiology Consult(Experienced- in addition to basic list)
-Adrenals: Sag of each with /without measurements. If abnormality present assess and save in transverse.
- Stomach: measure wall thickness in a few locations. Assess and record representative images
-Duodenum: SAg/Trans, measure wall
-SI: save a few images with/without measurements
-Pancreas: save representative images
-Colon: Learn how to trace colon and save representative images measuring wall. Assess ileocolic junction and ileum if possible.
-Lymph Nodes/Peritoneum: Assess for any lymphadenopathy, including sublumbar/medial iliac lymph nodes and take images especially if abnormal. Assess peritoneum for changes in echogenicity and the presence of effusion. Record images of abnormalities(peritonitis, mesenteric edema.
-Major Vessels: Aorts, Caudal Vena Cava and Portal Vein and record any abnormalities.
Measure organs
Adrenals, Renal length +/- width, Urinary bladder wall, gallbladder wall, GI wall thickness, Lymph nodes.
Focal Abnormalities
Annotate organ or structures you think abnormality is in and/or the surrounding landmarks. Provide images with/without measurements.
