Abdominal & Thoracic Ultrasound Flashcards
What are the 4 diferent probes u may use?
- 2-5MHz curvilinear (adult abdomen and thorax, pelvis, lumbar region)
- 4-8 MHz microconvex (also sector shaped, foal thorax/abdomen, ocular,
some MSK) - 7.5MHz (7.5-12) tendon probe (tendon, ligament, ocular, vascular, other
superficial structures) - 6.0Mhz (5-10) rectal probe (reproductive mainly)
Describe low frequency US?
– high penetration (20-40cm), sacrifice
resolution in near field. abdomen, cardiac
Describe medium frequency US?
– midrange penetration (10-20cm) and
resolution. thorax, abdomen, reproductive
describe High frequency US?
high resolution, sacrifice penetration. MSK,
umbilicus, ocular US, vessels
What patient prep for US?
» Ideal: Clip and wash away dirt & debris & apply US gel
» Alternative: alcohol saturation
(Isopropyl alcohol)
» Be sure to clean off probes after use!
» Cobs/obese/very hairy animals will generally need clipping
What are some non-acute indications for abdominal US?
- Weight loss
- Chronic colic
- PUO
- Suspected mass/abscess or neoplasia
- Evidence of organ disease
What are soem Acute indications for abdo US?
colic > FLASH
What is the systematic approach for a full abdo scan?
- R & L paralumbar regions
- R & L ICSs from ventral lung margins to CC junctions
- Entire ventral abdomen (sternum-inguinal)
- Rectal US if indicated (if want to further examine L kidney, palpable masses, bladder)
Describe locations of organs - where would you find everything?
What do you find on the LEFT of th ehorse?
What do we find on the RIGHT?
Left side liver view?
ICS 7-10
- relatively hyperechoic but less so than the spleen
Liver on right side?
- ICSs 8-14
- Should be dorsal to CC junction of ribs
- If more ventral than that: Hepatomegaly
View of spleen & stomach?
Spleen:
* Large amount of left side
Stomach:
* LHS ICS 8-15 deep to spleen and ventral to lung
* If extending beyond ICS 16-17 implies Gastric distension
View of the descending duodenum?
- ventral to R kidney
- Deep to R liver lobe
Where are we going to find Abnormalities in colic cass?
- SI
- LI
- Peritoneal effusion
Describe SI colic abnormalities?
- Increased wall thickness (≤3mm), distension, abnormal motility.
- Obstructive/surgical lesions: severe distension – lack of progressive motility, wall thickness can
be normal - Enteritis – can have similar appearance due to ileus (but may have wall thickening >3mm)
Large colon colic abnoramlities?
- Intraluminal gas/feed precludes evaluation of contents, distension and far wall
- Wall thickness difficult to measure in normal horses
- Normal is ≤3mm
- Left dorsal displacement (Nephrosplenic entrapment): L kidney and dorsal border of spleen may
be obscured by large colon - Right dorsal displacement or colon torsion – colonic mesenteric vessels abnormal size/location
Peritoneal effusion ?
If increased, assess quantity and echogenicity
How would you visualise body wall -> spleen & left kidney?
What would you see with nephrosplenic entrapment?
describe R dorsal displacement on US?
- Image shows normal
colonic mesenteric
vessel - With RDD: ~10th to
12th ICS, run
~parallel with the ribs
& look engorged.
What does FLASH stand for?
Fast Localised Abdominal Sonography of Horses
Describe FLASH scanning?
» Quick, useful in emergency setting
» Extensive US experience not required
» Main usefulness: Diagnosing strangulating SI
lesions
» Can help indicate whether referral (or
euthanasia) required
What probe ot use for FLASH?
LOW frequency probe
What are the 7 topographical regions to look at with FLASH scan?
- Ventral abdomen
- Gastric window
- Spleno-renal window
- Left middle third of abdomen
- Duodenal window
- Right middle third of abdomen
- Thoracic window (cranial ventral thorax)
What to look at in zone 1 - ventral abdomen?
Abnormalities:
- DSIs
- Si thickening
- Abnormal motility
- Free fluid
What to look for in Gastric window (2)
- Gastric distention
What abnormalities to look for in 3. spleno-renal window?
- Is L kidney visible?
- If not, poss LLD
What abnormalities to look for in 4. Left middle third of abdo?
- DSIs
- Colon wall thickeneing
- Abnormal motility
What to look for in duodenal window (5)?
- Thickening of duodenum of RDC
- Abnormal motility
What to look for in 6. Right middle third of abdo?
- Engorged colonic mesenteric vessels (Right
dorsal displacement or 180o
torsion) - Large colon wall thickening
- Duodenum – wall thickening, motility issues
What abnormalities to look for in 7. thoracic window?
Free pleural fluid
What are some indications for thoracic US?
» Suspectediastinal mass d or confirmed lower respiratory tract
infection
» Poor response to therapy
» PUO
Also:
- Cranial mediastinal mass (lymphoma)
- Rib fract
- Pneumothorax/haemoT
Review yoru anaotmy of lungs?
Discuss Pros and Cons of US?
What transducer to use for thoracic US?
» Transducers: dependent on availability and patient size.
* Usually curvilinear best
» Depth 4-10cm (15-25cm if severe pathology)
What technique for Thoracic US
» Start at the last (17th) ICS
» Scan from dorsal to ventral in each ICS to ventral lung margin
» Evaluate cranial mediastinum if any abnormalities identified in other ICS
What do normal lungs look like on US?
What are normal findings on lung US
» Aerated lung: ultrasound reflected by air -> Only the surface of normal lung can be evaluated.
» Lung should glide freely with inspiration
and expiration
» Pericardiodiaphragmatic ligament
(visible in horses with pleural effusion)
don’t confuse with fibrin
» Pleural fat
What does perocardodiaphragmatic lig?
What are some abnormal findings?
»Comet tail artefacts
»Consolidated lung (“hepatised”)
»Pulmonary abscessation
»Pleural effusion
»Atelectasis
»Fibrin
»Adhesions
Describe Comet tail findings?
Any irregularities of pleural surface:
- Early pneumonia
- Scarring from previous LRT infection
How to evaluate comet tails?
Interpret within current clinical picture &
whether other pathology is visible
* Size? Number? Distribution?
* Very fine comet tails wnl (esp neonates)
What are B lines?
o Artefact from the pleural
line
o Suggestive of alveolarinterstitial pathology
o Common finding in various
lung parenchymal disease
What does consolidated lung look like?
- Non-aerated lung
- Fluid and/or cellular infiltrate
- Usually cranioventral
- Various pathology from
pneumonia to neoplastic
disease
What does pukmonary abscessation look like?
- Well circumscribed
area(s) of consolidation - Only see peripheral abscesses
Abscess & fluid pockets?
Pleural effusion and atelectasis?
PNEUMOTHORAX
» Hard to differentiate from normal lungs
» Both pneumothorax and normal air-filled lungs will result in a hyperechoic line
» Clinical signs…
