Diagnostic Imaging PAVE edition

abdomen imaging principals

abdomen imaging principals

• X-ray

  • Always get two views (lateral and VD)

  • Try to expose at expiration

  • Always get the entire abdomen on film

  • organ margins

    use for fat animals

• US

  • organs and bowel wall

  • use when fluid is present

X-ray principles

• 5 Radiographic Opacities

  • Metal, Mineral, Soft tissue, Fat, Air

• Summation Sign

  • overriding of same opacities structures

• Silhouette Sign

  • touching of objects with same opacities

Serosal Detail of Radiographs

• Normal

  • Good detail

  • no free air

    • air is normal post sx for 21d

  • only a few drops of fluid

• Abnormal

  • Poor detail

  • Lack of fat

    • Emaciation or young

  • Presence of peritoneal fluid

    • RHF, peritonitis, hemorrhage

Normal Abdomen Liver on Radiographs

• extend to costal arch

• tapers

• don’t see gallbladder (right)

Normal Abdomen Spleen on Radiographs

• Left side next to stomach

• big, mobile, smooth

• Hyperechoic than both the liver or renal cortex 

  • SLinKy : brightness of organs

• hyperechoic fat near hilus

Normal Abdomen Stomach on Radiographs

• axis runs parallel to ribs or perpendicular to spine

• Lateral: fundus on top

• VD: fundus on left, pylorus on right

• artifactually pyloric mass

• 5 distinct layers

• 3-5mm thick, 5 waves/minute

Normal Abdomen Small Bowel on Radiographs

• Uniform diameter “Lazy loops”

  • <height lumbar vertebral body

• contains fluid and gas

• 5 distinct layers alternating in opacity

  • Serosal, Submucosal, and mucosal surface: hyperechoic

  • Muscularis propria and mucosa: hypoechoic

• 2-3 mm thick, 5 waves/minute

• Duodenum

  • Uniform diameter

    • <height lumbar vertebral body

    • cant evaluate wall thickness on x-ray

  • easy to find, other parts arnt

  • Dogs: right lateral

  • Cats: midline

Normal Abdomen Colon and Cecum on Radiographs

• descended with feces and gas

• mobile: no fixed area

  • Cant tell difference from constipation on xray: only by CS

• Cecum:

  • Dogs: gas filled

  • Cats: Cant see

Normal Abdomen Kidneys on Radiographs

• Dog: 2.5 – 4 x L2

• Cat: 2.5 – 3.5 x L2

• Kidney bean shape

• Retroperitoneal: not free floating on abdomen

• left is easiest to fine

  • Right: more cranial

• Hypoechoic to anechoic medulla

Normal abdomen visible structures on Abdominal Radiographs

• Good serosal detail

  • no free air only a few drops of fluid

    • air is normal post sx for 21d

• Liver

• Stomach

• Spleen

• Small bowel

• Colon and Cecum

• Kidney

• Prostate

  • can be seen in intact males

• Vasculature

  • caudal vena cava or deep circumflex iliacs

• Gallbladder

• Bladder

  • Anechoic urine

  • Smooth and distention

  • Don’t see urethra

What don’t you see in a normal abdomen view of Radiographs

• Adrenal glands (retroperitoneal)

• Gall bladder

• Ovaries

• Pancreas

• Lymph nodes

  • Sub lumbar

  • Mesenteric

  • Gastric

• Prostate

  • lie behind pubis/ilium or cranial to bladder

  • not seen in castrated dogs

  • Can be seen in uncastrated males

Abdominal mass effect

• Pushes the adjacent structures away from mass

• Cranial Dorsal

  • Head of spleen, Fundus, Kidneys, Adrenals, Ovary, Liver

• Cranial Ventral

  • Liver, Gallbladder, Pylorus

• Mid Abdomen

  • Spleen, Pylorus, Mesenteric LN, Kidneys, Adrenals, Ovaries, Small bowel

• Caudal Dorsal

  • Ureters, Kidneys, Sub lumbar LN, Colon

• Caudal Ventral

  • Bladder, Prostate, Uterus, Cervix

• Right Cranial

  • Liver, Gallbladder, Pylorus, Pancreas

• Left Cranial

  • Liver, Fundus, Pancreas

• Mid Abdomen

  • Kidneys, Adrenals, Ovaries, Mesenteric LN, Pancreas, Cecum, Transverse colon, Spleen

• Caudal Abdomen

  • Bladder, Colon, Prostate, Uterus, Sub lumbar LN

Liver Diseases on Radiographs

• Microhepatia

  • small size: not at ribs

  • stomach axis: cranially deviated

  • DDX.

    • normal: deep chested breeds

    • Young abnormal: Portosystemic shunt, hepatic microvascular dysplasia

    • Old abnormal: cirrhosis

• Hepatomegaly: older dogs

  • Large size

  • infiltrative dx: cushings

    • Focal

      • Neoplastic: Hemangiosarcoma, Adenocarcnima, Lymphosarcoma

      • Benign: Hepatoma, Nodular regen, Cyst, Abscess, Hematoma

    • Diffuse

      • Neoplastic: Lymphoma, Mast cell

      • Benign: Nodular regeneration, Hepatic lipidosis, Steroid hepatopathy, Vacuolar degeneration

• Mineralization

  • prior flukes, abcesses

• Hepatic Gas: rare

  • bacti infection

    
    

Sequelae to Hepatic Disease

• Formation of free peritoneal fluid

  • Transudate

    • Right heart disease and intrahepatic congestion

  • Modified transudate

    • Right heart disease

    • All types of infiltrative liver disease

  • Hemorrhage

    • Ruptured hepatic mass

• Vomiting

  • mass effect pushing on stomach

Splenic disease on Radiographs

• Large

  • Malignant

    • Hemangiosarcoma, Lymphoma, Mast cell, histocytosis

  • Benign

    • Hematoma, hepatoma

• Small

  • Hypvolemia

Gallbladder disease on Radiographs

• do not show up on x-rays

  • Cholecystitis(us), lucent gall stones(us), Biliary obstruction(mass)

• can show up on xrays

  • opaque gall stones, ruptured gallbladder, emphysematous cystitis(gas bacteria)

Kidney diseases on Radiographs

• Large

  • Malignant

    • Adenocarcinoma, Hemangiosarcoma, Lymphoma (esp cats)

  • Benign

    • PKD (flat nosed cats), Perinephric pseudocysts (around the kidney)

• Small

  • Idiopathic CKD

    • very common: older cats

  • Young animals

    • Renal hypoplasia or aplasia

• Mineralization

  • Dystrophic renal diverticuli

    • Faint, linear, extending into the kidneys

    • Old CKD cats

    • No obstruction

  • Renoliths

    • Focal, rounded, in renal pelvis

    • can cause obstruction

Adrenal Glands on Radiographs

• Normally not seen

  • mineralization: cats normal

    • mineralization in dogs is BAD

• cranial medial to kidney

  • right hugs vena cava

• Large

  • Cushing’s disease

    • Pituitary dependent

      • most common, both big

    • Adrenal dependent

      • one is big

  • Adrenal neoplasia

    • Adenocarcinoma, Phechromocytoma, lymphoma

Bladder disease on Radiographs

• Cannot evaluate urinary bladder wall thickness or what is within the bladder

  • silhouetting

• Normal variation

• Cystic Calculi: US

  • Opaque: Oxalate

    • rough/smooth

  • Mix: Xanthine, Struvite(smooth)

  • radiolucent: Urate / ammonium biurate, Cysteine

• Cystitis

  • looks normal

  • Emphysematous: air bubbles in bladder

• Obstruction

  • Mass in trigone

  • Stone in urethra

    • Tom Cats

    • ALWAYS get a “butt shot” on all male dogs with UT dx

• Rupture

  • May still look distended

  • Lack of serosal detail

  • Sample fluid for creatinine

  • Positive contrast or US to confirm

• Neoplasia

  • xray look normal

  • Transitional cell carcinoma: need US

    • common, aggressive

    • 90% dorsal trigone

  • Botryoid rhabdomyosarcoma

    • Very rare

    • looks like grapes

  • Leiomyosarcoma/leiomyoma/spindle cell tumors

    • apex

    • good prognosis

Prostate disease on Radiographs

• not seen if castrated

• Prostatomegaly: big

  • BPH: benign

    • Intact male dogs

    • castration fixes

  • Prostatitis

    • Staph or strep

    • dogs VERY sick

  • Prostatic neoplasia

    • Adenocarcinoma, transitional cell carcinoma

    • mineralization of prostate = cancer

  • Paraprostatic cysts (next to)

    • 3 bladders on lateral view

      • 1) bladder, 2) prostate, 3) cyst

      • fluid filled: benign

Lymph node disease on Radiographs

• not seen normally

  • Mesenteric nodes: mid abdomen

    • Gastric – caudal to stomach

    • Porta hepatic – in porta-hepatis region

  • Sub lumbar nodes: largest

    • Ventral to L6-7, dorsal to bladder

      • fungal, cancer

  • Iliac nodes

    • On either side of aortic trifurcation

• Lymphadenopathy

  • regional mass effect

  • Lymphoma, metastatic lymphadenopathy, reactive nodes
    

Uterine disease on Radiographs

• Pyometra

  • Puss filled infection

  • tubular shape seen dorsal to bladder and ventral to colon: lateral view

• Uterine neoplasia

  • Leiomyosarcoma, adenocarcinoma

Pregnancy on Radiographs

• Seen 42d

  • defined mineralization to the carpi/tarsi

• Death

  • gas everywhere: fetus or uterus, mineralization, overlapping skull bones

Ovarian Pathology on Radiographs

• ovaries normally not seen

• neoplasia will cause a mass effect

Stomach positional differences on Radiographs

• Pylorus : right, smaller

  • Lat – ventral portion of stomach

  • VD – on the right side

• Fundus: left, larger

  • Lat – dorsal portion of stomach

  • VD – on the left side

  Bubble method

  • Right lateral: pylorus positioned down and fluid filled

    • can ‘fake’ a mass like appearance

  • Left lateral: pylorus positioned up and gas filled

Stomach abnormalities on Radiographs

• Gastric Bloat

  • stomach is filled with fluid, gas, or ingest

  • extreme dilation

• Gastric Foreign Body

  • indigestible objects in stomach

  • Lucent: plastic, wood, glass, fabric, seeds/pits

  • Opaque: bones, rocks, metal, glass

• Gastric Dilatation and Volvulus

Duodenum abnormalities on Radiographs

• Dogs: right lateral most abdominal wall

• Cats: more midline

• “Sentinel loop” sign

  • Pancreatitis and 2dry functional ileus

    • not sensitive

  • mildly gas distended on both views

• Wall diseases

  • Lymphosarcoma, adenocarcinoma, leiomyosarcoma
    

GI Obstruction vs Enteritis on Radiographs

• Obstructive ileus: sx case

  • 2+ populations of bowel!

  • Segmental dilatation, sharp turns(hair-pen), stacking loops

• Functional ileus: medically manage / sx

  • Uniform diameter, mildly distention, wide lazy loops

• Mechanical Ileus

  • 2ndary to FB, wall disease, extra-luminal mass

• Foreign Bodies

  • Lucent: plastic, wood, glass, fabric, seeds/pits

  • Opaque: bones, rocks, metal, glass

  • Linear(cats): string, dental floss

    • plicated bowel, bunching, odd gas patterns

    • sx intervention required

  • Extra-Luminal Obstruction Rare

    • Secondary squishing from other organ mass

Bowel Wall Thickness evaluation on Radiographs

• cannot be accurately done on x-rays

  • combo of fluid and gas filled

• diameter is < height of a lumbar vertebral body

  • should be uniform

• Gas distended bowel

  • wall looks thin and smooth

• Partially fluid filled

  • gas floats to top

  • wall falsely looks thick

• Completely fluid filled

  • Fluid silhouettes

  • can’t see the inner margins of it at all

Normal liver on Ultrasound

• Medium level, rough, homogeneous, “salt-and-pepper” echogenicity

• S>L>K (SLinKy) : brightness descending order

• Prominent, tapering vessels

• Smooth margins

• Intra-Hepatic Vasculature

  • Portal veins: drain, white walls

    • Nutrient rich, deoxygenated blood from intestines to liver 

    • Anechoic tapering tubes with hyperechoic walls

  • Hepatic veins: drains

    • Deoxygenated blood from liver to cava to right heart

    • Anechoic tapering tubes with walls you can’t see

  • Hepatic arteries

    • Oxygenated blood that supplies liver parenchyma

    • Not seen at all

• Extra-Hepatic Vasculature

  • Portal vein

    • flaccid, anechoic tube

    • ventral and medial to the caudal vena cava

  • Caudal vena cava

    • flaccid, anechoic tube

    • dorsal and slightly to the right of midline

    • can trace into and through diaphragm

Hepatic Disease on Ultrasound

• Passive congestion

  • Right heart failure, caval syndrome

• Portasystemic shunts: US/CT best

  • intrahepatic: Lg dogs

  • extrahepatic: Sm dogs/cats

    • single vessel shunts

      • Portal-caval, Portal-azygous, Portal-renal

    • multiple vessel shunts

• Benign

  • Hepatic lipidosis(brighter), nodular regeneration, cirrhosis, cholangiohepatitis, hepatic abscess, hepatic cysts, tumors, hematoma, hepatocutaneous syndrome

  • Nodules: Round, defined margins, non-cavitary, homogeneous, small, uniform

• Malignant

  • Dogs: Hepatocellular adenocarcinoma(dogs), Hemangiosarcoma, Lymphosarcoma(cats)

  • Cats: Cholangiocellular adenocarcinoma, Lymphosarcoma

  • Nodules: Irregular shape, poor margins, cavitary, heterogeneous, bulge, large, variation : malignant

• Infiltrative dx

  • DDX. NSAIDS, steroids, mast cell, acute hepatitis, lymphosarcoma

Diseases of the gallbladder on Ultrasound

• Cholelithiasis

• “Sludge”

  • shadowing, non gravity dependent suspension

• Biliary obstruction

• Cholecystitis

• Biliary mucocoele

  • kiwi and honey bun variety

• Gall bladder rupture

• Congenital anomalies

  • Bilobed gall bladder

  • Double gall bladder

Splenic Disease on Ultrasound

• Benign

  • Hemangioma, Hematoma

  • Passive congestion

  • Extramedullary hematopoesis

  • Torsion/infarction

  • Splenitis

• Malignant

  • Hemangiosarcoma

  • Lymphosarcoma: honeycomb

  • Mast cell tumor

  • Extra-cellular osteosarcoma

Renal diseases on Ultrasound

• Benign

  • Calculi

    • pelvic calculi

    • dystrophic mineralization of diverticuli

  • Chronic renal disease

    • “old cat kidneys

  • Obstructive renal disease

    • Ureterolith(s)

    • Transitional cell carcinoma in bladder, prostate or urethra

    • Severe prostatic disease

    • Chronic ureteral stricture

  • Cortical infarction

  • Ethylene glycol toxicity

  • Pyelonephritis

  • Feline Polycystic Renal disease

  • Perinephric pseudocyst

• Malignant

  • Primary adenocarcinoma

  • Metastatic renal disease

  • Lymphosarcoma

Bladder Disease on Ultrasound

• Benign

  • Calculi

    • Hyperechoic with posterior shadowing

      • Don’t adhere to wall

    • Sand type looks like hyperechoic line

  • Blood clots

    • Well defined, irregularly mass

  • Cystitis

    • thick wall

    • Inner mucosal margins are roughened

    • debris floating

  • Rupture

    • can cause an overlap seal

    • Most common in apex

    • free fluid

  • Ectopic ureter: always leaking urine from day 1

    • Moderate sensitivity, needs high frequency or doppler probe

    • eddy formation as urine enters from ureter

• Malignant

  • Transitional cell carcinoma: trigone

    • defined irregular, sessile based

    • caudodorsal or cranioventral (cats)

  • Botryoid rhabdomyosarcoma

    • rare, young dogs, “cluster of grapes”

Normal reproductive system on Ultrasound

• Ovaries

  • caudal to the kidneys

  • not often seen but can be seen during estrus

  • normal anechoic follicles just before ovulation

• Uterus

  • Don’t see normally

  • Located just dorsal to bladder

  • Post partum

    • tubular mass dorsal to bladder

    • Placental sites gone 4w

    • debris 3w

    • Completed involution 4m

• Pregnancy

  • detect pregnancy and viability

    • 15d anechoic gestational sacs are seen

    • Nearly 100% accurate at 21d

    • Heart beat by 21d

    • movements seen at 28d

    • Internal organs 50d

  • poor for counting fetuses

Normal male reproductive tract on Ultrasound

• Testies

  • homogeneous, smooth

  • Mid linear, hyperechoic “rete testis”

• Prostate gland

  • Can hide behind pubis

  • moderately hyperechoic and uniform

Female repro abnormalities on Ultrasound

• Ovarian cysts

• Neoplasia

  • adenocarcinomas

    • bilateral and solid

  • granulosa cell tumors

    • unilateral and cystic

  • leiomyosarcoma

  • leiomyoma

  • adenocarcinoma

• Pyometra

• Endometriosis

• Fetal death

  • no heart beat after 21d

  • lungs and sac have gas/reverb artifacts

  • no organs or movement

Male repo disease on Ultrasound

• Orchitis

  • infection of testicle parenchyma

• Hydrocoele

  • anechoic fluid around testicle

• Seminoma and interstitial cell tumors

  • appear as mixed echogenic masses within testicle

• Sertoli cell tumor

  • hypoechoic nodules

  • common in retained testicles

• Epididymitis

  • increased echogenicity of the epididymus

Prostate gland disease on Ultrasound

• Benign prostatic hypertrophy

  • neuter

• Prostatitis/abscessation

  • painful, very sick dogs

  • neuter

• Paraprostatic cysts

  • fluid filled outside prostate

  • neuter

• Prostatic neoplasia

  • Adenocarcinoma

  • very common in neutered dogs

Adrenal Glands and Lymph Nodes on Ultrasound

• Adrenal Glands

  • difficult to find

  • Symmetrical in size

  • VD to evaluate thickness

    • sm pets< 4mm,

    • med pets< 6mm,

    • Lg pets<9mm

  • Left Gland

    • Cranial medial to left kidney, lateral to aorta

    • between cranial mesenteric and left renal artery

  • Right Gland

    • Cranial medial to right kidney

    • Between caudal cava (black tube) and portal vein.

• Intra-Abdominal Lymph Nodes

  • Round

  • capsule not seen

  • sub-lumbar: ventral to last 2-3 lumbar

  • Mesenteric nodes: not seen

    
    

Normal Pancreas on Ultrasound

• Can find in 50% of time

• Right lobe is medial to descending duodenum

• Left lobe is caudal to stomach, cranial to colon

• Pancreatitis

  • US better than rads

  • Moderate to severe to be seen

  • complex, mixed echogenic masses, free fluid

  • Secondary biliary stasis and paralytic ileus of descending duodenum

• Pancreatic neoplasia and abscesses

  • insulinoma - sensitivity is poor

  • adenocarcinoma

Adrenal issues on Ultrasound

• Pituitary Dependent Hyperadrenalcorticism

  • Bilateral, Common to look normal to enlarged

  • No invasion

  • Cushing’s in dogs

• Adrenal Dependent Hyperadrenalcorticism

  • Unilateraly big, other is atrophied

  • Mass effect, no invasion

  • Uncommon in dogs

• Adrenal Neoplasia

  • Adenocarcinoma

    • large, irregular, invasive mass, bilateral

    • Dystrophic mineralization

    • poor prognosis

  • Pheochromocytoma

    • large, irregular, invasive mass, unilateral

    • good prognosis

• Lymphadenopathy

Bowel diseases on Ultrasound

• Benign

  • Functional (paralytic) ileus

  • Mechanical (obstructive) ileus

  • Chronic gastritis

  • Diaphragmatic hernia

  • Inflammation/gastritis/enteritis

  • Inflammatory bowel disease (IBD)

• Malignant

  • Lymphosarcoma

  • Adenocarcinoma

  • Leiomyoma

  • Leiomyosarcoma

Neuroradiology

• Covers head and axial skeleton

• Based off of symmetry

• General anesthesia is a must

Hydrocephalus

• Cause:

  • Overproduction or obstruction to outflow of CSF: choroid plexus

    • high production, low absorption

  • Congenital or acquired

    • Dome head toy breeds

• CS:

  • dull mentation, seizures, incoordination

• Views:

  • Closed mouth VD and lateral

    • 5% will show x-ray signs

• RS:

  • Open fontanel and suture, caudal osseous tentorium, ground glass look, thin cortex, dilated lateral ventricles

    • Adults, may look normal

Occipital Dysplasia

• Cause:

  • Congenital defect of foramen magnum

    • young Dome head toy breeds

• CS:

  • cervical pain, hind limb neurologic deficits

• Views:

  • Lateral, closed mouth VD, slight obliqued VD

  • Needs MRI/CT scans

• RS:

  • Abnormal foramen magnum with open dorsal extension

    • “keyhole” shape

    • herniation possible

Chiari Syndrome

• Cause:

  • King Charles Cavalier Spaniels

• CS:

  • neck pain, mentally dull, ear scratching

• RS:

  • Caudal crowding of the cerebellum with herniation via foramen magnum

    • Normal X-rays

Cranial Mandibular Osteopathy

• Cause:

  • Unknown but self limiting

  • Young westies

    • 4-11 months

• CS:

  • Pain, cant open mouth, muscle atrophy, Soft tissue swelling

• Views:

  • Closed mouth VD and lateral view

• RS:

  • Osteoproductive lesion of mandible/TMJ/bulla, NO lysis

Otitis Media

• Cause:

  • Bacteria mid ear infection

    • secondary to chronic otitis external

  • Floppy eared old dogs

• CS:

  • Head tilt, ear pawing, exudate, seizures

• Views:

  • Closed mouth VD, open mouth VD, obliques

    • CT / MRI is preferred

• RS:

  • Thick osseous bulla with lysis, increased soft tissue density in bulla, mineralization of external ear canals, increased opacity of tympanic bullae, nasopharyngeal polyp

Normal contents of the ear

• tympanic bullae

  • air

• external ear

  • air

X ray positioning of the head

• Done sedated

• Open mouth VD

  • #1 for nasal passages

  • Closed mouth obstructs passages

• Lateral View

• Frontal Sinus View

• X-rays are insensitive for nasal dx

  • CT preferred

Destructive rhinitis

• Cause:

  • Neoplastic

    • Old, Lg dolichocephalic dogs (long)

    • Adenocarcinoma

  • Fungal rhinitis

    • Lg dogs

    • Aspergillus + blastomycosis

• CS:

  • Mucopurulent to bloody discharge

  • Neoplastic: Uni to bilateral discharge, facial deformity’s, external masses

  • Fungal: Uni discharge, facial/external deformities are RARE

• Views:

  • Open mouth VD, lateral, skyline frontal sinus

    • X-rays insensitive for nasal dx

    • CT prefered

• RS:

  • Increased nasal passage opacity, turbinate destruction, bone lysis

Non-destructive rhinitis

• Cause:

  • Older animals

  • Bacti, fungal, viral, FB, allergys, parasites, Kartagener’s

• CS:

  • Serous to mucopurulent discharge

• Views:

  • Open mouth VD, lateral, skyline frontal sinus

    • X-rays insensitive for nasal dx

    • CT prefered

• RS:

  • Increased nasal passage opacity, nasal turbinates blurring, NO lysis or septal deviation

Temperomandibular Joint TMJ

• Cause:

  • Congenital or acquired

• CS:

  • luxation, instability of the jaw, weight loss, pain, cant open mouth

• Views:

  • Closed mouth VD, obliques

• RS:

  • irregular articular surfaces, joint incongruity, luxation, DJD

Spinal anatomy

• Rib heads

  • articulate in front of their assigned #

• 7 cervical vertebrae

  • C2 dorsal arch over lap C1

  • C 2-3 narrow disc space

  • C6 Lg lamina ventral to transverse process

    • sled runners

  • C7 dorsal spinous process in Lg

• 13 thoracic vertebrae

  • C7-T1 narrow disc space

  • T10-11 narrow disc space , bulb articular process

  • T11 anticlinal vertebrae, straight dorsal spinous process

  • Dorsal spinous process point caudally

  • Disc herniation are rare cranial from T1-T10

• 7 lumbar vertebrae

  • L3 and L4 attach diaphragm

  • Transverse processes increased opacity

  • Dorsal spinous process point crainally

• 3 sacral vertebrae

  • 20-23 coccygeal vertebrae

• Accessory process

  • increased disc opacity

  • overlay the intervertebral foramen and insults in increased opacity within the neurocanal

  • often not present

Atlantoaxial Instability

• Cause

  • Congenital (95%)

    • malformation of dens C2

    • lig. malformation

    • Mini dogs

  • trauma to dens

• CS

  • Ataxia, paralysis, proprioception issues, cervical neck pain, shows up under 1yr old

• Views

  • Straight lateral C-spine, lateral dens view, slightly flexed lateral, VD

• RS

  • C1- C2 large joint space, Sm/missing dens, dens fracture

• DDx.

  • disk herniation, neoplasia, trauma, central CNS dx

Block vertebrae

• @ any location

• Cause

  • Congenital

  • Boxers, Bulldogs, Bostons, Shar Pei, Chondrodystrophoids, Manx

  • failure of proper segmentation

• CS

  • stable, incidental, can cause surrounding aging issues

• RS

  • vertebrae fusion, lack of disc

Hemivertebrae

• Cause

  • Congenital

  • Bostons, bulldogs, pugs

• CS

  • incidental, stable

• RS

  • Abnormally shaped or short vertebra, odd curvature of spine

Transitional Vertebrae

• Cause

  • Congenital

  • Boxers, Bulldogs, Bostons, Shar Pei, Chondrodystrophoids, Manx

  • anomalous formation of TL and LS junctions

• CS

  • incidental

• RS

  • Sacralization of L7 via illiac fusion

  • Lumbarization of S1 via transverse process/disc development

Terms used to describe vertebral curvature

• Lordosis

  • Ventral deviation of spine

    • looking at the lord

• Kyphosis

  • Dorsal deviation of spine

• Scoliosis

  • Lateral deviation of spine

Spina Bifida

• Cause

  • Congenital malformation and failure of fusion of dorsal arches

  • Bostons, bulldogs, Pug, Manx

    • screw tails

  • failure of fusion of dorsal lamina on dorsal arches and spinous processes

• CS

  • Young: clinical

  • Old: non-clinical

• Views

  • Lateral and VD

• RS

  • 2 paired dorsal spinous processes, missing/blunted L7 dorsal spinous, distended colon or bladder

  • SB occulta= bony defect

  • SB manifesta= meninges and spinal cord herniated through bony defect

Spondylosis Deformans

• Cause

  • Joint instability, idiopathic

  • Degenerative

    • Animals over 1yr

  • Bone exostosis projecting from the

    vertebral endplates

• CS:

  • No CS, incidental

• Views

  • Lateral and VD

• RS

  • Smoothly marginated, bony bridging

Discospondylitis

• Thoracic and lumbar spine are the most common sites

• Cause

  • Bacti infection of discs and end plates

    • staph, strep, e coli, brucella

    • Hematogenous infections

    • can be secondary

      • septic emboli

  • GSD, Danes, Males

• CS

  • Young, focal back pain, reluctance to move or ambulate, neuro deficits to limbs, bony lysis

• Views

  • Lateral and VD of entire spine

• RS

  • Osteolytic focal lesion, wide/narrow intervertebral disc space

Spondylitis

• Cause

  • Bacti infection of ventral vertebral body

    • staph, strep, e coli, brucella

    • Hematogenous infections

    • can be secondary

      • septic emboli

• CS:

  • Middle age to older dogs and cats, >2 years most commonly, back pain, reluctance to move or ambulate, neuro deficits to limbs, fever

• Views

  • Lateral and VD

• RS

  • Loss of vertebral body concave margin, bony productive lesion on ventral vertebral body, rough

Intervertebral Disc Disease

• Cause

  • disc protrusion or extrusion of nucleus pulposis

  • Type 1

    • calcification in situ, acute herniation

    • chondrodystrophoid dogs

  • Type 2

    • Incomplete with slower onset

  • Rare @ T1-T9 due to intercapital ligament

• CS

  • Older, pain, paralysis

• Views

  • Lateral and VD: cant diagnose

  • MRI

• RS

  • Narrow disc space, increased intervertebral opacity, mineralized disc

Myelogram

• iodinated contrast: agent injected around spinal cord space surrounding the spinal cord (subarachnoid space)

  • specific nonionic, low osmolar agent

  • Iohexol or omnipaque

• ID areas of cord compression or deviation

  • Extradural

    • Lesion outside dura mater

  • Intradural-extramedullary

    • Lesion in subarachnoid space

  • Intramedullary

    • Lesion in spinal cord

• Complications

  • invasive

  • seizures, vomiting, bradycardia, exacerbation of neuro issues, death

Vertebral Tumors

• Primary tumors: stops growing when pet stops growing

  • usually located in only one vertebral body

    • Except Osteochondroma or multiple cartilaginous exostoses

      • Multiple vertebrae and/or ribs

  • Most are lytic

  • Osteosarcoma is most common

• Metastatic Tumors

  • multiple vertebral bodies

    • tumors through body

  • lytic or periosteal

• RS

  • osteolytic or osteoblastic lesions, compression

  • MM: multiple areas of moth-eaten diffuse lysis

  • MCE: bony mass displacing and compressing the Spinal cord

Cervical Vertebral Instability (Wobbler’s Disease)

• Cause

  • Inheritable

  • Great Danes, Dobermans

  • cervical disc spaces are unstable, spinal cord interference, dorsally displaced vertebral body, hypertrophy of dorsal longitudinal lig. disc protrusion/extrusion

• CS

  • Old, male, ataxia, cervical pain, hemi to tetraparesis, wide based stance

• Views

  • Straight lateral and VD

    • myelography and dynamic views

    • 80% can be ID with x-rays (controversial)

• RS

  • Narrowed/wedge disc space, dorsal deviation of vertebral body, spinal mal alignment of C5-6, C6-7, C4-5, cord compression that worsens during neck extension

Lumbosacral Instability

• Cauda Equina Syndrome

• Cause

  • Instability of L7-S1, disc protrusion or extrusion, hypertrophy of dorsal longitudinal lig.

  • Transitional vertebrae may predispose

  • GSD

• CS

  • older, rear limb ataxia, worn dorsal nails, pain during full extension of pelvis, reluctance to position to defecate

  • Fecal and urinary incontinence

• Views

  • Lateral and VD

  • Need MRI

• RS

  • Narrowed/wedge, Spondylosis, ventral step lesion at L7-S1

  • Full colon

Hyperparathyroidism

• Cause

  • hyperfunctional parathyroid gland

  • hypercalcemia caused by the elevated PTH.

  • Primary Hyperparathyroidism from adenoma of the parathyoid gland

  • Secondary Hyperparathyroidism from diet or chronic renal failure

• RS

  • Skull demineralization, generalized osteopenia with cortical thinning, prominent endplates, prominent teeth opacity

Radiology and skeletal healing

• Normally must have 30-50% bone loss prior to seeing it

• Lytic changes will not be seen for 7-10 days

• Productive changes may not be seen for 14 days

Soft tissue radiology

• Extracapsular tissue swelling

  • Blood, pus, edema outside joint

  • Not centered around a joint

• Intracapsular tissue effusion

  • Blood, pus, edema within a joint

  • Centered around a joint space

• Soft Tissue Emphysema

  • Gas inside body

    • Outside: petrating injury or sx

    • Bacti sorce: emphysematous bacteria like Clostridia

    • From body: pneumoarthrogram (cracks)

• Soft Tissue Mineralization

  • Dystrophic

    • Focal

    • Dead, dying tissue

    • Metaplasia to mineral

    • Normal Ca:P

  • Metastatic

    • Diffuse

    • Abnormal Ca:P

Periosteal Reactions

• Healing process in response to injury with Sharpey’s fibers

• Solid / Homogeneous

  • Periosteum is lifted and new bone has filled space beneath it

  • well defined

• Lamellated

  • alternating opacities

  • cyclic ongoing processes

  • Active, aggressive lesions

    • Osteomyelitis, fungal disease, neoplasia

• Spiculated

  • spicules at right angles with the bone

  • pus, neoplastic cells between spicules

  • Form along Sharpey’s fibers

  • aggressive process

    • infection, neoplasia, fungal

• Amorphous “wispy”

  • Looks like anything

  • Aggressive process

    • neoplasia

• Codman’s Triangle

  • Lifting of periosteum by radiolucent cells at lesion edge

  • aggressive processes

    • osteomyelitis, neoplasia

Osteoporosis

• Cause

  • overall decrease bone mass

    • normal composition just not enough

  • Old, Cushing’s, hyperparathyroidism, Addison’s, steroids, low calcium

• RS

  • Cortical thinning, bone lucency, prominent trabeculation, “egg shell” vertebral bodies

Osteomalacia

• Cause

  • abnormal matrix, normal mass

    • “Soft bone”

  • CKD, low vit D or Ca

  • Hypophosphatemia

• RS

  • decreased bone opacity, cortical thinning, angular limb deformities

Osteopenia

• Generalized term to describe focal or generalized decrease in bone density

Osteosclerosis

• Cause

  • increase in bone mass

  • hormonal imbalance (female birds), metabolic, neoplasia, incidental (cats)

• RS

  • thick cortical thickening, increased marrow opacity

Focal or Regional Bone Loss

• Disuse osteoporosis

  • 50% loss before seen

  • 10d “no use”

• Geographic bone loss

  • Focal lytic lesion in bone

  • Center is necrotic/pus

  • May be expansile

• Punctate (permeative) lysis

  • Multi, sm lysis regions

    • can coalesce

  • Indistinct margins

  • Aggressive process

Bone Parts

• Epiphysis

  • end of bone, articular part

• Physis

  • growth plate or line

  • Distal radial plate

    • 80% of growth, closes 9 mths

  • Distal ulna plate

    • 85% of growth, closes 10 mths

• Metaphysis

  • widened part between shaft and growth plate

• Diaphysis

  • shaft of long bone

Growth Plate Injuries

• Cause

  • skeletally immature < 10 months

• Salter Type I

  • Separation entire physis

  • shearing forces

  • good prognosis

• Salter Type II

  • most common

  • through physis and metaphyseal

  • triangular shaped bone frag

  • good prognosis

• Salter Type III

  • through articular surface, epiphysis and physis

  • intra-articular shearing force or a torsional force

  • Fair prognosis

• Salter Type IV

  • through epiphysis, physis, and metaphysis

  • often older animals

  • poor prognosis

• Salter Type V

  • through physis

  • severe crushing forces

  • poor prognosis

Premature Physis Closure

• Distal Ulnar

  • Short ulna

  • Radius may bow

  • Distal radius is subluxated craniomedially from the radial carpal bone

  • foot deviates laterally

  • wide humero-ulnar joint

  • common

• Distal Radial

  • Short radius

  • Wide radiocarpal and radiohumeral joint space

  • elbow/carpus degeneration

Fracture classifications

• Open Fracture (compound fracture)

  • exposed to enviro

• Closed Fracture (simple fracture)

  • contained in the body

• Incomplete Fracture

  • partial break

  • immature animals “greenstick” fracture

• Fissure Fracture

  • incomplete fracture off of a complete fracture

• Depression Fractures

  • multiple fissure fractures

  • common in skull

• Complete Fractures

  • complete loss of bony continuity

    • deformed

• Transverse Fracture

  • transverse to the long axis

  • bending forces

• Oblique Fractures

  • oblique to the long axis

  • two cortices of each fragment are in the same plane without spiraling

  • bending forces

• Spiral Fractures

  • fracture line that spirals along the long axis

• Comminuted Fracture

  • +3 interconnected fractures

  • high energy trauma

• Multiple Fracture

  • +3 not interconnected fractures

• Impaction or compression fracture

  • bony fragment forced into cancellous bone

  • end of long bones

• Avulsion Fracture

  • violent contraction of a muscle rip off bone

• Chip fracture

  • fragment

• Slab Fracture

  • expansile articular fracture

• Pathological Fracture

  • secondary to disease

Bone Healing types

• Primary

  • ideal

  • direct growth of an Haversian system

  • does not occur across fracture gaps

  • RS

  • Lack callus

  • Gradual decreased opacity and fracture line

• secondary

  • common

  • when rigid internal fixation does not exist

Factors That Affect Bone Healing

• Vascular Integrity

  • poor blood flow reduces healing

• Location

  • Metaphyseal heal faster

  • diaphyseal heal slow

  • antebrachial heal slow

  • Cancellous bone heal fast

  • Cortical bone heal slow

• Mobilization

  • rigidity heals fast

• Type

  • complicated heals slow

• Postreduction Apposition

  • good apposition heals fast

• Age

  • young heals fast

• Local Trauma

  • with severe soft tissue injury heals slow

  • infectsion slows healing

  • malignancy slows healing

• Bone loss

  • excessive distraction heals slow

• Corticosteroids

  • slow healing

  • inhibit the differentiation of osteoblasts

Evaluation of fractures

• alignment, joints, rotation, fixation

• Tx. Sx or casting

  • 6 cortices engaged with screws above and below the fracture site

• Complications

  • Malunion and warping

    • hard to see in young dogs till mature

  • Delayed Union

  • Non Union

    • no healing for 90d

    • atrophy of region

    • Hypertrophic

      • lysis

      • Cortical discontinuity

      • Non bridging callus

      • angular deformity

    • Atrophic

      • Min callus formation

      • defined gaps

Osteochondrosis

• Cause

  • dysfunction of endochondral ossification

  • thick weak cartilage

    • chips off

• CS

  • young Lg breed males

  • front limb lameness

• Location

  • Shoulder (#1): caudal or caudal-lateral humeral head

  • Elbow: distal medial humeral condyle

  • Stifle: distal lateral femoral condyle

  • Tarsal: medial trochlear ridge of the talus

• RS

  • Calcified flap of articular cartilage, secondary DJD, Joint effusion

• DDx

  • long digital extensor fossa can be confused for an OC lesion

Fragmented Medial Coronoid Process

• Cause

  • Young Lg male dogs

  • elbow dysplasia

• CS

  • Stiff front end, lameness, elbow pain, DJD in older animals

• Rs

  • osteoarthritis, osteophytes on the anconeal process and radial head, sclerosis of the trochlear notch of the proximal ulna, repair on medial coronoid process of the ulna

Ununited Anconeal Process

• Cause

  • Anconeal process forms from a separate center of ossifications

    • unfused

  • Young Lg dogs

    • GSD

• CS

  • weight bearing lameness

• RS

  • Irregular radiolucent line cross the anconeal process

Retained Cartilaginous Core

• Cause

  • Young Lg dogs

  • Unknown

  • core of cartilage in the metaphysis

  • issue of osteochondrosis of the distal ulnar physis

  • cartilage does not transform into bone

• CS

  • self limiting

  • retard growth of the distal ulnar physis causing angular limb deformity

• RS

  • Conical shaped radiolucent zone extending from the distal ulnar physis into the distal ulnar metaphysis

Panosteitis

• Cause

  • Young male Lg dogs

    • GSD

• CS

  • self limiting, front limb lambess, front limb long bone pain

• RS

  • Increased intramedullary opacity, blurring of the trabecular pattern, patchy medullary opacities, rough endosteal surface

Hypertrophic Osteodystrophy

• Metaphyseal flaring – lacy bony appearance around physeal

• Cause

  • Young Lg male dogs

• CS

  • Self limiting, lamness, painful, swelling around long bones, Pyrexia

• RS

  • necrotic marginated line parallel to physis, metaphyseal flaring

Legg Calve Perthes Disease

• Cause

  • Young SMALL dogs

  • necrosis of the capital femoral epiphysis from poor blood supply

  • Unilateral

• CS

  • Weight bearing lameness, leg pain

• RS

  • Increased width of joint space and opacity of femoral head, patchy lysis

• FHO sx

Hypertrophic Osteopathy

• Cause

  • old dogs with lung dx

  • Hormonal, neural, hypoxia

  • Begins on the abaxial surface of digit 2,5 and moves proximally

• CS

  • pulmonary dx or masses, 4 limb lameness, distal limb swelling

• RS

  • irregular periosteal reaction of tubular bones and accessory carpal/calcaneous

Degenerative Joint Disease

• Cause

  • multifactorial, non-septic disorder of synovial joints

  • deterioration of articular cartilage leading to inflammation of joint

• CS

  • slow onset progressive intermittent lameness, work out of lameness with movement

• RS

  • Intracapsular swelling

  • Increased joint space if acute, decreased size if chronic destruction of the cartilage

  • articular cartilage proliferation in non weight bearing areas

    • cartilage proliferation outgrows it nutrient supply

  • Perichondral osteophytes

  • Detached pieces of articular cartilage, Joint “mice”

Septic Arthritis

• Cause

  • Adults with penetrating wounds or no wound history in puppies

  • Joint infection

• CS

  • Severe pain and joint effusion, lameness, fever, anorexia, lethargy, single joint (except puppies)

• RS

  • tissue swelling, chronic bony changes, gas in tissue, lysis, severe subchondral erosion

Hip Dysplasia

• Cause

  • High estrogen

  • Lg dogs

    • GSD

  • genetic or environmental

  • laxity of the coxcombical joint

• 3 months to 3 years (often worse at 9-11 months) or at old age

• CS

  • lameness, pain, restricted potion, difficulty standing and climbing

• RS

  • cranial joint wedging, <1/2 of the femoral head covered by dorsal acetabular rim, thick femoral neck, shallow flat acetabulum, osteophytes

• Evaluation

  • Penn Hip: 4mths

    • measured distance between the femoral head center and the acetabular center with pressure added

    • 0 = tight

      • >0.4= high risk

    • 1= luxated

  • OFA

    • must be 24m of age or older

    • extended VD view evaluated by radiologists for subluxation, shallow acetabula, remodeling, osteoarthritis

    • Excelent = improved

    • Good= normal

    • Fair= minor issues

    • Borderline= marginal issues

    • Mild= minor dysplastic changes

    • Mod = defined dysplastic changes

    • Severe = marked

• TX.

  • Triple Pelvic Osteotomy in young dogs, hip replacement, Femoral Head and Neck Ostectomy as a salvage procedure

Cranial Cruciate Disease (CCL)

• Cause

  • Young athletic (acute) or fat dogs (chronic)

  • degeneration, separation, weaking of the lig

• CS

  • Non weight bearing lameness, patellar luxation

• RS

  • cranial tibia displacement, “Rad Drawer sign”, Intracapsular swelling squishing fat pad, joint mice from evulsion fracture, swelling of the medial joint capsule (medial butrus), osteoarthritis

Patellar Luxation

• Cause

  • Medial young sm dogs

  • Lateral young Lg dogs

  • congenital or traumatic

• CS

  • lameness

• RS

  • Patella is medial to trochlear groove, lateral bowed distal femur, Medial proximal tibia bowing and quadriceps muscles, shallow tronchlear groove, osteoarthritis

Arthridities

• Destructive (erosive)

  • Lysis and erosion of articular and cortical bone

  • Narrow joint

  • Intracapsular effusion

• Non-destructive (non-erosive)

  • no Lysis or erosion of articular and cortical bone

  • Narrow joint

  • Intracapsular effusion