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radiology

  1. 5 things to evaluate for in radiology
    distribution, opacity, margins, displacement of structures, and location
  2. distribution (3)
    focal (discrete, spherical space-occupying lesion), multifocal (multiple), diffuse (entire organ enlarged, usu without focal bulges. Frequently systemic, like diabetes or lymphoma)
  3. CHANG
    • Cyst, Hematoma, Abscess, Neoplasm (carcinoma or sarcoma rather than lymphoma), Granuloma
    • usually focal or multifocal
  4. opacity (5 + examples)
    • Diagnostic clue about density vs surrounding structures, thickness.
    • Gas (abscess, perforation, gas-producing bacteria), Fat (lipoma), Fluid/soft tissue (neoplasm, granuoma, cyst, abscess), Mineral/bone, Metal/Contrast
  5. margins
    • description of outer borders of mass
    • well defined vs poorly (invasion into tissues, fluid, inflammation)
  6. mass effect
    • effect of mass :) 
    • displacement of tissues, organs etc
  7. displacement of structures
    • clue to size and origin
    • eg, SI is displaced craniodorsally, something caudoventral is enlarged
  8. gastric axis displacement
    • method for telling displacement of structures or changes in abdominal organs. 
    • imaginary line between fundic and pyloric parts of stomach drawn on both lateral and VD
    • shrot dogs, should be parallel to ribs in lateral and perpendicular to vertebral column in VD
    • Perp to vertebral column in both lat and VD in deep chested dogs
    • Cardia is fixed in place, pylorus is moveable.  
    • Caudal displacement: liver enlargement (neoplasia, DM, Cushings)
    • Cranial displacement: microhepatia (PSS, chirrosis, chronic liver dz), diaphragmatic hernia, caudal abdominal mass, pregnancy
  9. Location (2)
    • regional or organ description.  Organ if you can tell, regional when it is unclear.
    • regional: cranial (within rib cage, hypochondriac), middle, caudal (thigh overlap) thirds. Can narrow with left, right, dorsal, ventral
  10. roentgen signs
    • size, shape, number, location, opacity, margin
    • +/- mass effect
  11. Views for GDV
    R lateral
  12. views for pylorus and duodenum
    left lateral
  13. views for free peritoneal gas
    horizontal beam VD
  14. views for urethra
    extended and flexed hip lateral radiographs
  15. Ultrasound
    • high frequency sound waves to create an image
    • evaluated by echogenicity (relative brightness).  Hypo (dark), iso, hyper (bright)
  16. hyperechoic
    more echoic, brighter on U/S
  17. hypoechoic
    less echoic (darker on U/S)
  18. descending echogenicity
    • fluids
    • renal medulla
    • adrenal glands
    • muscle
    • renal cortex
    • liver, pancreas
    • lymph nodes
    • spleen
    • prostate
    • renal sinus
    • structured fat
    • gas
    • mineral
  19. poor serosal detail in peritoneum differentials
    • peritoneal fluid
    • peritonitis
    • peritoneal neoplasia
    • cachexia (less body fat)
    • young (<6mo, fat more fluid and some normal peritoneal fluid)
  20. anechoic
    very black on U/S
  21. echogenic
    cellular fluid on U/S, exudate, high protein.  Hemorrhage, purulent
  22. pneumoperitoneum
    • free gas in peritoneum. 
    • increased serosal detail, gas along body wall and between diaphragm and liver
    • Horizontal beam VD in L lateral.  
    • ddx = perforation of GI tract, penetration of abdominal wall, gas-producing bacteria
  23. Retroperitoneum: what's there and what bad detail means
    • kidneys, ureters, adrenal glands, medial iliac lymph nodes, major blood vessels
    • poor detail: unable to see renal margins, distension displaces abdominal organs ventrally.  
    • ddx: fluid (hemorrhage, urine from ruptured ureter), neoplasia (hemangiosarc), abscess
  24. pneumoretroperitoneum
    • usually from pneumomediastinum
    • penetrating wound
    • gas-producing bacteria (very little)
  25. diagnosing heptomegaly
    • diffuse or focal? 
    • caudally displaced gastric axis, caudal displacement of abdominal organs, rounded lobar edges
  26. microhepatia
    • congenital liver disease (PSS, microvascular dysplasia)
    • chronic liver failure (cirrhosis)
    • cranially displaced gastric axis
    • less than 2 intercostal spaces on lateral
  27. gallbladder
    • not well seen on rads, look on U/S instead (little bag of (black) fluid). Gas in gallbladder or mineral seen in rads
    • Seen as ventral bulge from liver in cat rads (screening).
  28. Spleen
    • head is fixed, tail is mobile. Not usu seen in cat lateral rads
    • focal mass: benign or malignant tumor, hematoma, abscess.
  29. ddx for diffuse splenomegaly
    • normal position: extramedullary hematopoiesis, congestion/sedation (acepromazine), infiltrative neoplasia (lymphoma, MCT), infection (mycoplasma haemofelis), infarct
    • abnormal position: splenic torsion
  30. gastromegaly ddx
    • abnormal location: GDV - double bubble, popeye!
    • normal location: bloat (gas vs ingesta), aerophagia, GI obstruction, GB, pyloric outflow tract obstruction (L lat), gastric wall mass
  31. SI
    • pretty much everywhere except liver and retroperitoneal
    • look at wall layering on U/S.  Cats <12mm, dog <1.6xheight of L5 on Lat (>2.4 = obstructed)
    • Enlarged loops can be focal/segmental or diffuse
  32. ileus and ddx
    • inability to propel ingesta aborally
    • mechanical: intussception, intestinal wall mass
    • functional/paralytic: neuromuscular or vascular abnormalities in bowel wall.  Systemic illness, pancreatitis, infection, opioids, post-sx
  33. linear foreign body
    • thin, string-like foreign material, usually anchored in pylorus or under the tongue, extends into SI
    • causes plication and bunched SI.  Eccentric teardrop-shaped gas (paisley! or commas).  Fluid getting through.
  34. concentric vs eccentric (SI walls)
    • concentric: both sides bigger
    • eccentric: only on part, ONE side bigger
  35. Large intestine and content
    • fluid: diarrhea!
    • FB
    • enlarged: megacolon vs constipation
  36. pancreas
    • normally not visible (blends in)
    • increased opacity/loss of serosal detail caudal to stomach (mass effect)
    • lateral and/or ventral displacement of duodenum
    • caudal displacement of transverse colon
    • hypoechoic on U/S
  37. adrenal glands
    • normally not visible
    • enlarged: caudolateral displacement of cranial pole of kidney
    • mineral can indicated adrenal carcinoma in dogs.  Some mineral normal in cats.
  38. Kidneys
    • L more caudal than R
    • compare to length of L2 on VD. Dog = 2.5-3.5x, cat = 2.4-3x, as low as 2 in older cats.
    • Eval for mineral
  39. Renomegaly ddx
    • one kidney: hydronephros, perinephric pseudocyst
    • both kidneys: infection, lymphoma, bilateral hydronephros
    • lobulated: neoplasia, cysts, abscess
    • look for ventral displacement of abdominal organs
  40. little kidney ddx
    • Older animals: chronic renal insuffiency
    • young: renal dysplasia or hypoplasia
    • often big kidney/little kidney
  41. Urinary bladder
    • Invisible after trauma: rupture?
    • displaced: body wall hernia (perineal)
    • can use + or - contrast (+ iohexal for rupture, double contrast adds gas to eval bladder wall and radiolucent calculi
    • Look at ENTIRE urethra
  42. radiolucent urinary stones
    • Cysteine and urate (I can't C U)
    • take both angles so you're not confused by fabellae
  43. urinary bladder wall mass
    Transitional Cell Carcinoma
  44. Prostate and ddx for enlarged
    • Not visible in cats
    • Enlarged: dorsal displacement of colon.  Usu neoplasia in castrated male.
    • Enlarged in intact: benign prostatic hyperplasia, prostatitis, cysts, neoplasia, abscess
  45. ovaries
    • 4x greater in size before seen on rads, usu seen in ventral abdomen
    • mistaken for intestinal/peritoneal mass
  46. uteromegaly
    • increased opacity between colon and bladder
    • pregnancy will show fetal mineralizationat day 41-45 in dogs and 35-45 in cats
    • pyometra, mucometra, hydrometra, hemometra
  47. lymph nodes
    • Not visible on rads unless enlarged
    • medial iliac LN: increased opacity ventral to L6-7, ventral displacement of colon.  
    • Mesenteric LN: mid-abdominal mass effect
  48. Rad selection for pneumonia, pleural fluid
    • L Lat and V/D
    • U/S for lg animal
  49. Rad selections for cardiac disease
    R Lat and DV
  50. Rad selection for pulmonary metastasis
    L lat, R Lat, DV
  51. Localize disease to body wall by:
    • Peripheral location to opacity
    • extra-pleural sign
  52. Localize disease to pleural space by:
    • opacity silhouettes with heart or diaphragm
    • wide pleural fissures
    • pulmonary blood vessels do not extend into periphery
  53. localize disease into lungs by:
    • opacity partial-to-complete silhouettes with pulmonary blood vessels
    • air bronchogram
    • lines and rings
    • Lobar sign
  54. Localize disease to mediastinum by:
    Opacity is midline location (VD/DV)
  55. localize disease to cardiac silhouette by:
    mid- to ventral midline location
  56. Airspace
    Pulmonary acini and smaller
  57. bronchovascular bundle
    large airways, blood vessels, lymphatic, CT
  58. Pulmonary hyperlucency
    • lungs appear darker
    • result in increased gas to soft tissue = increased air, decreased blood flow
    • Obstructive emphysema, feline asthma, hypovolemia
  59. pulmonary opacification
    • lungs appear whiter
    • result of DECREASE in gas to soft tissue ratio
    • decreased air
    • increased blood flow
    • increased fluid or cells in alveolar space
    • increased fluid or cells in the alveolar wall
    • Must localize to airspace (unstructured, ground glass vs consolidation), lines or dots (structured)
  60. airspace opacification
    • Ground glass opacity: interstitial pattern, partially aerated.  Unstructured opacification WITHOUT border effacement of pulmonary blood vessels
    • consolidation: alveolar pattern, void of air.  Unstructured opacification WITH border effacement of pulmonary blood vessels (air bronchogram, lobar sign)
  61. air bronchogram
    • Visible LUMEN of bronchus, but not airspace - vessels around bronchus and walls not visible
    • IF YOU SEE PULMONARY BLOPOD VESSELS, NOT AN AIR BRONCHOGRAM
    • if you DO see one, it means lung consolidation (but doesn't HAVE to be there)
  62. lobar sign
    • Seeing not only the interlobar fissure but one entire LOBE is white and the other is not.
    • Indicates lung consolidation
  63. parallel lines and rings
    Diffuse bronchial and axial interstitial disease
  64. Bronchietasis
    Lumen of bronchioles gets wide, ends abruptly, lose tapering.  Irreversible damage, lifelong treatment
  65. three types of dots
    • Miliary - 1mm
    • small (nodule) - <3cm
    • large (mass) - >3cm
  66. incomplete lung expansion
    • could cause appearance of disease or worse disease than is actually there.
    • Atelectasis or collapse: restrictive, obstructive, relaxation, cicritizing
    • signs: decreased lung size, increased opacity, lobar sign, crowding of ribs, air bronchogram, positive silhouette sign, poorly defined margins of vessels, mediastinal shift (towards collapse), crowding and reorientation of pulmonary blood vessels, compensatory hyperinflation, bronchial rearrangement, cardiac rotation, displacement of diaphragm, rounded pulmonary margins, displacement of pleural fissures, changed location of abnormal structures
  67. components of lung patterns
    • how opacity of lungs is altered: increased, decreased
    • shape of pulmonary opacification: airspace opacification, lines, dots
    • lung expansion: fully expanded or not
    • macroscopic distribution of abnormalities
    • severity, distribution, shape (large, focal pulmonary mass)
  68. Cranioventral airspace disease ddx
    • Pneumonia (bronchopneumonia vs aspiration)
    • hemorrhage
    • neoplasm
  69. lobar or sublobar airspace disease ddx
    • Pneumonia (bronchopneumonia vs aspiration)
    • hemorrhage
    • neoplasm
  70. caudodorsal to diffuse airspace disease ddx
    • Cardiogenic pulmonary edema
    • non-cardiogenic pulmonary edema (upper airway obstruction, toxin inhalation, ALI (SIRS/ARDS), near drowning, neurogenic, vasculitis, DIC
    • lymphoma
  71. patchy/asymmetric airspace disease ddx
    • Trauma
    • infection
    • neoplasia
    • hemorrhage
    • inflammation
  72. bronchocentric airspace disease ddx
    inflammatory, neoplasm, atelectasis
  73. Diffuse bronchial and axial-interstitial disease ddx
    • All causes of bronchitis: allergic, infectious, immune-mediated
    • lymphatic spread of neoplasia
    • early congestive heart failure
  74. diffuse peripheral-interstitial disease ddx
    Idiopathic pulmonary fibrosis
  75. CHANG
    • for focal or multi focal nodules or masses
    • Cyst
    • Hematoma
    • Abscess
    • Neoplasm
    • Granuloma
  76. sternum and chondral rib damage ddx
    • degeneration (incidental, nbd)
    • trauma
    • infection
    • neoplasia
    • pectus excavatum
    • upper airway obstruction
  77. acute vs chronic rib lesions
    • Neoplasia vs fractures
    • acute has sharp margins, chronic has smooth
  78. Extra-pleural sign
    • pulmonary opacity with oblique margins that taper slowly to thoracic wall
    • disease in BODY WALL not lung
    • cat under the rug (edge of lung deflected in)
  79. signs of pneumothorax (9)
    • gas within pleural cavity.  Can be open (from outside) or closed (from lung)
    • PULMONARY VESSELS DO NOT EXTEND TO BODY WALL
    • retraction of lung from body wall
    • lungs smaller than normal
    • lungs increased opacity
    • dorsal displacement of heart
    • mediastinal shift (toward collapse when normotensive, away with tension)
    • flat diaphragm (tension)
    • barrel-chested (tension)
  80. causes of dorsal displacement of the heart
    • normal conformation
    • pneumothorax
    • hypovolemia
  81. signs of pleural fluid
    • retraction of lung from body wall
    • lungs smaller than normal
    • lungs increased in opacity
    • blunting or rounding of lung margins
    • wide pleural fissures (interlobar or inconsistent)
    • silhouetting of heart (on DV) and diaphragm
  82. causes of pneumomediastinum
    • tracheal laceration
    • pharyngeal laceration
    • esophageal laceration
    • penetrating body wall injury
    • Often self-limiting - don't treat, just watch in case develops to fatal pneumothorax.  Could be secondary to jug venipuncture or tracheostomy tube placement
  83. wide cranial mediastinum
    • width exceeds twice that of a vertebrae
    • fat, abscess, neoplasm, hemorrhage, lymphadenopathy, cyst (esp cats)
    • Bulldogs naturally have wide mediastinum
  84. Thoracic lymph nodes
    • sternal: dorsal to second sternebrae
    • tracheobronchial: vague opacity surrounding carina, NOT dorsally displacing
    • cranial mediastinal
  85. thymic mass
    • sail sign, point going left at cranial margin of the heart
    • thymic lymphoma or thymoma
  86. signs of diffuse esophageal enlargement
    • ventral tracheal displacement
    • tracheal stripe sign (broad line, walls look thick)
    • "V" sign: V where esophagus goes through diaphragm
  87. dynamic tracheal collapse
    • extra-thoracic: collapse during inhale
    • intra-thoracic: collapse during exhale
    • Grades: 1 = 25%, 2 = 50%, 3 = 75%, 4 = chondromalacia
  88. Which imaging modalities for which musculoskeletal probs? (5)
    • radiographs: osseous lesions
    • ultrasound: soft tissue injury and biopsy
    • computed tomography: complex osseus lesions (surgical planning)
    • Magnetic Resonance Imaging: neurological and soft tissue injury
    • Nuclear imaging: extent of lesions, localizing lameness
  89. diffuse vs localized bone loss - recognition
    • diffuse: osteopenia.  Reduced opacity, thinned cortices, double cortical sign (double line, resorption), folding fractures.  (disuse, metabolic, senility, protein deprivation
    • localized: osteolysis.  well-marginated, solitary  (cysts, neoplasia)
  90. Identify different forms of osteolysis (3) vs periosteal reaction (4) and what they suggest about aggressiveness of underlying pathology
    • osteolysis:
    • permeative: small foci of lucency, often on periphery of lesion. AGGRESSIVE
    • moth-eaten: poorly marginated, regions of irregular bone loss, AGGRESSIVE
    • geographic: well-marginated, solitary, +/- surrounding sclerosis = new bone formation. NON-AGGRESSIVE

    • periosteal reaction:
    • amorphous interrupted: Rapid progression of disease, ill-defined and irregular.  Hazy whisps, loss of organization, MOST AGGRESSIVE
    • irregular interrupted: lesion causing rapid periosteal stimulation.  New bone is irregular.  AGGRESSIVE
    • brush-like interrupted: slow lifting or reaction of periosteum.  NON-AGGRESSIVE VS AGGRESSIVE
    • solid continuous: well-marginated, slow smooth new bone formation.  NON-AGGRESSIVE
  91. causes of common congenital (3) and developmental conditions (4) that affect bone growth
    • congenital: malformation (vertebral from curly tail/curly spine, spina bifida with unclosed vertebrae), too few (aplasia) or too many (polydactyl)
    • developmental: too short/angulation (growth plate injury), dyssynchronous growth of paired bones (joint incongruency ie premature growth plate closure or elbow dysplasia), incomplete ossification (humeral condyle, anconeal process, axis), diffuse growth abnormalities (congenital hypothyroidism, mucopolysaccharidosis, rickets, hypervitaminosis A, Pituitary dwarfism)
  92. causes for incomplete bone fractures
    • osteopenia
    • osteolysis
    • sclerosis
    • immaturity, stress, pathology like tumor.  NOT normal in adult animal.
  93. classification and description of fractures: 
    incomplete: greenstick, stress, pathological
    complete: simple, comminuted, segmental, compression, depression, folding, chip fractures, slab fractures, avulsion fractures, Physeal (Salter Harris type 1 through 5)
    • incomplete: (abnormal in adults, common in neonates)
    • Greenstick: longitudinal within bone, in IMMATURE dog
    • stress: small semi-circle, from outside, partway through bone
    • Pathological: aggressive bone tumor, loss of cortical margin

    • Complete: 
    • simple: one break, 2 parts
    • comminuted: many fragments
    • segmental: 2 breaks that don't connect
    • compression: shortening of bone
    • depression: break that sinks like in skull
    • folding: diffuse osteopenia, nutritional
    • chip fractures: articular to exterior surface, corner
    • slab fractures: articular to articular, shear off whole side of bone
    • avulsion fractures: chunk of bone off ligament attachment
    • Physeal: salter Harris type 1 (physis only, immature iwth physis still open), type 2 (physis to metaphysis), type 3 (physis to epiphysis), type 4 (metaphysis and epiphysis), type 5 (not a fracture, just a compression of growth plates, cause short and long paired bones)
  94. what happens when a joint gets inflamed, and how is that reflected on rads?
    • effusion: bulging soft tissue opacity
    • synovitis
    • osteophytosis: small pockets of periosteal reaction, new bone growth 
    • cartilage erosion
    • subchondral sclerosis: brighter white areas near osteophytosis
    • subchondral cyst formation: darker areas
    • subchondral bone erosion: moth-eaten, patchy areas
  95. underlying causes of joint inflammation
    • autoimmune
    • infection
    • cartilage lesion (chronic, developmental)
    • instability (trauma, degeneration, developmental)
    • incongruency
  96. erosive vs non-erosive arthropathies
    • erosive: rheumatoid arthritis, canine idiopathic erosive polyarthritis (carpus/tarsus, look like holes).  Osteophytosis, swelling, holes. 
    • non-erosive: idiopathic polyarthritis, systemic lupus erythmatosus, polyarthritis-polymyositis syndrome, polyarthritis-meningitis.  Usu milder, just cause effusions (joint tap)
  97. recognize an OCD lesion
    semi-ossified cartilage flap in joint where there should not be bone.  Cartilage tearing off bone histologically.  Flaps of loose cartilage will ossify
  98. when appropriate to perform stressed rads on a joint
  99. radiographic features observed with cranial cruciate ligament rupture, hip dysplasia and elbow dysplasia
    • CCLR: center 1/3 of distal femur (condyle eminence) BEHIND tibia, not contacting on rads. Cranial drawer. Effusion.
    • Hip Dysplasia: <50% of dorsal acetabular head overlapping femoral head ("Morgan's Line"), causes subluxation and chronic inflammation
    • Elbow Dysplasia: radius and ulna of different lengths/incongruent, joint space different sizes on either side of olecranon.  See osteophytosis in flexed rad.  Ulna is high, prone to fracture due to sclerosis.  opposite side of joint from olecranon fragmented and malformed
  100. recognize lysis observed with synovial cell sarcomas in joints
    soft tissue tumor invading bone, causing progressive lysis.  darker than soft tissue opacity swelling (FAST, 2-4wks), lifting of periosteum.
Author
XQWCat
ID
330496
Card Set
radiology
Description
Block Va radiology
Updated

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