Basic Abdominal Ultrasound

WWW.UVSONLINE.COM

Amanda Breyette, LVT

[email protected]

Kristina Wilson DVM, DACVR

[email protected]

BASIC ABDOMINAL ULTRASOUND

ANATOMY AND RECOGNIZING NORMALS

11/14/2017CE FALL 2017 | BASIC ABDOMINAL ULTRASOUND

mailto:[email protected]

mailto:[email protected]

WWW.UVSONLINE.COM

The goal of performing an abdominal ultrasound is to obtain diagnostic quality images that can then be interpreted to answer a clinical question.

EX: Why is the patient vomiting or having diarrhea? Is there an underlying cause of renal disease? Is there an intestinal obstruction?

GOALS


WWW.UVSONLINE.COM

Always communicate prior history. Does this patient have a history of abdominal surgery- previous splenectomy? Hx of pancreatitis? Elevated liver enzymes? Spayed/Neutered?

HISTORY


WWW.UVSONLINE.COM

Fast your patient for 12 hours – no food, water ok

Hold urination for 1-2 hours prior to exam

Make sure ultrasound machine is labeled with correct patient – as the images are part of the medical record

Shaving

Far lateral - kidneys

Intercostal spaces in deep chested dogs

Choose appropriate probe size

The higher the frequency the lower the depth of penetration

Pick the highest frequency for your patient

Linear vs curved transducer

Indications

Uniform gain through entire image

Focus is on point of most interest

Depth

PREPPING FOR ULTRASOUND


WWW.UVSONLINE.COM

Sector Transducers (real time B-mode)

Electronic

Curvilinear array

Phased array

Linear array

Transducers

TYPES OF TRANSDUCERS


WWW.UVSONLINE.COM

Utilize your v-troughs

Start in dorsal recumbency

Change positions – left and right lateral recumbency

If your patient is comfortable they will stay still (or be more likely to stay still)

Use sedation when needed !!!

Torbugesic/Midazolam - 0.2-0.4mg/kg

Torbugesic can cause panting and can cause ileus

Acepromazine- splenomegaly

Dexmedetomidine- slow HR, big cava

Perform scan in same sequence every time

Systematic approach –

Organ to organ

START OF EXAM


WWW.UVSONLINE.COM

Depth

Always set to be able to see the deepest margin of organ being imaged

Focus

Set within region of most interest

Set where measurements are taken

Overall gain

Often left alone

May need to change if poor contact (increase) or if abdominal fluid (decrease)

TGC

near and far fields

Slides set to (b)right for deeper structures

KNOBOLOGY


WWW.UVSONLINE.COM

KNOBOLOGY


WWW.UVSONLINE.COM

Obese

Falciform fat

Depth

Thin

Nothing separating the organs

Landmarks are distorted

IMAGING ISSUES


WWW.UVSONLINE.COM

IMAGING ISSUES


WWW.UVSONLINE.COM

Always get 2 views

Sagittal plane view – marker faces cranial

Cranial is to the left on the screen

Transverse/ventral view – marker faces right.

Right intercostal view – marker faces dorsal

Left intercostal view – marker faces ventral

Radiologist needs to know right from left!!!

ORIENTATION


WWW.UVSONLINE.COM

Sagittal Plane

ORIENTATION


WWW.UVSONLINE.COM

Transverse Plane

ORIENTATION


WWW.UVSONLINE.COM

Left intercostal view


WWW.UVSONLINE.COM

Right intercostal view


WWW.UVSONLINE.COM

Sagittal View Transverse View

ORIENTATION


WWW.UVSONLINE.COM11/14/2017CE FALL 2017 | BASIC ABDOMINAL ULTRASOUND

ALWAYS LABEL AND ARCHIVE!

REMEMBER TO CHANGE LABELS AS YOU

GO

WWW.UVSONLINE.COM

Liver/Gallbladder

Stomach

Pancreas-left limb (cat)

Spleen

Left Kidney

Left Adrenal

Bladder

Urethra

Prostate

Colon

Right Kidney

Right Adrenal

Pancreas- right limb (dog)

Small intestine

Lymph nodes

CREATE A SYSTEMATIC APPROACH


WWW.UVSONLINE.COM

Located in the cranial abdomen

Intercostal in deep chested dogs

Always obtain the right dorsal intercostal view

Move from right to left to ensure you image the entire liver

Cranial is the diaphragm

Far left is the spleen

Caudal is the stomach

Make sure depth is set to see all diaphragm to get dorsal liver

Caudate lobe of liver, right dorsal intercostal

LIVER


WWW.UVSONLINE.COM

When evaluating liver size use your stomach as a landmark.

In the sagittal view, the ventral portion of left liver should not extend beyond the gastric body. The edge should also be tapered, not rounded.

The right liver should not extend caudal to the right kidney.

Usually mildly hypoechoic and coarse in comparison to the spleen and isoechoic to the cortex of the kidney.

Spleen-liver-renal cortex – SiLK

Falciform fat is isoechoic and coarse echotexture, located between the right and left liver lobes

LIVER


WWW.UVSONLINE.COM

Normal Cat Normal Dog

LIVER


WWW.UVSONLINE.COM

Right Dorsal Intercostal View Right Dorsal Intercostal View

LIVER


WWW.UVSONLINE.COM

Sagittal view – small liver Right Dorsal Intercostal View

LIVER


WWW.UVSONLINE.COM

Located in the right cranial abdomen within the right liver lobe

Varies in size

Becomes distended in anorexic or fasted patients

Bilobed in ~25% of cats – rarely in dogs

GALLBLADDER


WWW.UVSONLINE.COM

Wall thin and smooth

1mm in cats

2mm in dogs

Sludge

Reposition to confirm sludge vs. mass

Not common in cats

Almost always in dogs

Common Bile Duct (CBD) can be seen more easily in cats

GALLBLADDER


WWW.UVSONLINE.COM

Bilobed Common Bile Duct

GALLBLADDER


WWW.UVSONLINE.COM

Sludge

GALLBLADDER


WWW.UVSONLINE.COM

Standing Dorsal Recumbency

GALLBLADDER


WWW.UVSONLINE.COM

Located in mid cranial abdomen

Fundus, body, pyloric antrum – left to right

Gas distraction

Rugal folds and peristalsis

Measures 2-5mm in the dog and 1.7-3.6mm in the cat

Try to identify the pyloric sphincter

STOMACH


WWW.UVSONLINE.COM

Body Rugal Folds

STOMACH


WWW.UVSONLINE.COM

Gas distraction Pylorus

STOMACH


WWW.UVSONLINE.COM

Head, body and tail

Head and body located in the mid/left cranial abdomen

Tail can cross midline

“tongue” shaped

Margins are usually tapered

Hyperechoic with a fine echotexture in comparison of the liver/renal cortex

SPLEEN


WWW.UVSONLINE.COM

In large or deep chested dogs the head of the spleen can be more easily seen when the patient is in right lateral recumbency and imaged left dorsal intercostal.

The spleen can be folded on itself making it appear larger

Individual variations in size

1cm width at hilus in cats

< 3.5cm in most dogs

SPLEEN


WWW.UVSONLINE.COM

Cat Spleen Dog Spleen

SPLEEN


WWW.UVSONLINE.COM

Dog Spleen Cat Spleen

SPLEEN


WWW.UVSONLINE.COM

Should be symmetrical in size and shape

Oval (particularly in cats) or bean shaped

In cats the normal length is 3.0-4.5cm

In dogs the length varies due to size/breed

5cm in 50# dog

6cm in 60# dog

7cm in 70# dog

No kidney should be above 11cm no matter how big the dog is

Cortex is usually hypoechoic or isoechoic to the liver and hypoechoic to the spleen

Can be hyperechoic in overweight cats

Medulla is hypoechoic

Pelvis is not usually seen

Can be slightly distended in animals who are on fluids

KIDNEYS


WWW.UVSONLINE.COM

Located in the left cranial-mid abdomen

Can be difficult to visualize when patients have a full colon

LEFT KIDNEY


WWW.UVSONLINE.COM

Parasagittal Sagittal

LEFT KIDNEY


WWW.UVSONLINE.COM

Transverse Transverse

LEFT KIDNEY


WWW.UVSONLINE.COM

Hypoechoic to the surrounding fat

When using a high frequency transducer you can see the cortex and medulla

Can be mistaken for vessels – use your doppler

In cats the glands are short, ovoid or cylindrical

10-11mm long and ~4mm in width

In dogs the glands are elongated and have a more classic “peanut” shape

10-50mm long and up to 8mm in width

Measure both poles

ADRENAL GLANDS


WWW.UVSONLINE.COM

Located medial to the left kidney

Use your vasculature as landmarks

Lateral to the aorta

Cranial to the left renal artery

Dorsal/ventral to the left phreniocoabdominal artery and vein

Vein is easier to see and splits the gland into two poles

Fan ventral/dorsal until the gland is located

Asymmetry in poles could indicate a tumor

LEFT ADRENAL


WWW.UVSONLINE.COM

Small Dog Large Dog

LEFT ADRENAL


WWW.UVSONLINE.COM

Cat Cat

LEFT ADRENAL


WWW.UVSONLINE.COM

Dog Cat

LEFT ADRENAL


WWW.UVSONLINE.COM

Located on midline in the caudal abdomen

Best to image when the bladder it is moderately distended

Can place a u-cath and fill the bladder with 0.9% NaCL

Wait for it to fill naturally

Urine should be anechoic

Wall thickness decreases and the volume increases

Larger bladder = decreased wall thickness

In cats normal wall thickness is up to 1.7mm

In dogs it varies depending on side of the bladder

URINARY BLADDER


WWW.UVSONLINE.COM

Sagittal Cat Transverse Cat

URINARY BLADDER


WWW.UVSONLINE.COM

Sagittal Dog Transverse Dog

URINARY BLADDER


WWW.UVSONLINE.COM

Located in the caudal, left, cranial and right abdomen.

Left = descending

Right = ascending

Cranial = transverse

Often filled with gas and/or feces

Empty colon

Wall is hyperechoic

Transverse view almost looks like a tiny stomach

Has a thinner wall than the small bowel

Measures 2-3mm in the dog and 1.4-2.5mm in the cat

COLON


WWW.UVSONLINE.COM

Sagittal Transverse

COLON


WWW.UVSONLINE.COM

Empty Empty

COLON


WWW.UVSONLINE.COM

Neutered dogs

Hypoechoic and ovoid

<2cm in length

Intact dogs

Large, hyperechoic, uniform echogenicity, bilobed

Size varies with age

Similar echogenicity to spleen

PROSTATE


WWW.UVSONLINE.COM

Neutered Dog Intact Dog

PROSTATE


WWW.UVSONLINE.COM

Located in the right cranial/dorsal abdomen

More difficult to image

In large or deep chested dogs it can be more easily seen when the patient is in left lateral recumbency and imaged intercostal

RIGHT KIDNEY


WWW.UVSONLINE.COM

Sagittal Dog Transverse Dog

RIGHT KIDNEY


WWW.UVSONLINE.COM

Sagittal Large Dog Sagittal Cat

RIGHT KIDNEY


WWW.UVSONLINE.COM

Located in the right cranial quadrant close to the caudal vena cava

Fan ventral/dorsal through the CVC until the gland is visualized

Image intercostal

Use transverse approach

RIGHT ADRENAL GLAND


WWW.UVSONLINE.COM

Dog Cat

RIGHT ADRENAL GLAND


WWW.UVSONLINE.COM

5 different layers

Lumen, mucosa, submucosa, muscularis, subserosa/serosa

High frequency probe

Mucosa is the thickest layer

Measure form the outer aspect of the serosa and to the inner border of the mucosa

Descending duodenum

Located in the far right cranial/mid abdomen

Thicker than the remainder of small intestine

Measures 3-6mm in dogs and 2-2.5mm in cats

Duodenal papilla

SMALL INTESTINE


WWW.UVSONLINE.COM

Jejunum

Located in the mid abdomen

Measures 2-5mm in dogs and 2-3 mm in cats

Ileocecocolic Junction

Located in the right cranial abdomen

More easily visible in cats

Often difficult to identify due to gas collection in this area

Ileum is more easily identifiable due to its prominent and bright submucosal layer

Measures 2-4mm in dogs and 2.5-3.2mm in cats

Often thick muscular layer at the terminal part of the ileum

SMALL INTESTINE


WWW.UVSONLINE.COM

Wall Layering Wall Layering

SMALL INTESTINE


WWW.UVSONLINE.COM

Duodenum Cat Duodenum Dog

SMALL INTESTINE


WWW.UVSONLINE.COM

Duodenal Papilla

SMALL INTESTINE


WWW.UVSONLINE.COM

Jejunum Jejunum

SMALL INTESTINE


WWW.UVSONLINE.COM

Ileocecocolic Junction Ileocecocolic Junction

SMALL INTESTINE


WWW.UVSONLINE.COM

Use your vessels as landmarks

Numerous lymph nodes within the abdomen and each have a different draining area

Mesenteric/Jejunal

Located along the cranial mesenteric artery and vein

Uniformly echogenic, isoechoic or slightly hypoechoc to the surrounding fat.

Thin hyperechoic capsule

Usually <4cm in cats and <5cm in dogs

Increased in puppies

Can be up to 1cm

-Medial iliac

Located at the caudal aortic trifurcation

More easily identifiable by using a lateral flank approach

Measure up to 7-8mm

LYMPH NODES


WWW.UVSONLINE.COM

Mesenteric/Jejunal Right Iliac

LYMPH NODES


WWW.UVSONLINE.COM

Has 3 portions

Right, left and body

Right lobe dorsomedial to the descending duodenum and ventral to the right kidney

The body is caudal to the pyloric region

The left lobe is dorsocaudal to the gastric antrum and crosses midline

Can be seen between the stomach and transverse colon

If you can see the stomach, spleen and left kidney in the same picture chances are the left pancreas is in there too

Homogeneous and is isoechoic or slightly hyperechoic

PANCREAS


WWW.UVSONLINE.COM

Dog Cat

PANCREAS


WWW.UVSONLINE.COM

Side-lobe

Grating-lobe

Mirror-image

Acoustic enhancement

Acoustic shadow

ARTIFACTS


WWW.UVSONLINE.COM

Intense echoes from lateral lobes are mismapped as being within main lobe

Occurs with high reflective interfaces lateral to anechoic object in main beam

Correct by lower gain, lower frequency, change orientation or deeper focus

SIDE LOBE ARTIFACT


WWW.UVSONLINE.COM

SIDE LOBE ARTIFACT


WWW.UVSONLINE.COM

Acoustic enhancement Mirror image

ARTIFACTS


WWW.UVSONLINE.COM

REFERENCES


WWW.UVSONLINE.COM

MISCELLANEOUS


WWW.UVSONLINE.COM

”

“ QUESTIONS

QUESTIONS?


Basic Abdominal Ultrasound

Education

Transcript of Basic Abdominal Ultrasound