Diagnostic Imaging: Approach to Abdominal Imaging Flashcards
What are the advantages of radiology and ultrasound?
Radiology Adv
* Good overview
* Better to assess size and shape
Radiology Dis
* Poor at assessing GIT wall changes and internal architecture
US adv
* Excellent to assess internal architecture and luminal spaces
US dis
* Operator dependent
* Poor in presence of extensive gas
What radiographic considerations are there for the abdomen?
- Low kV, high mAs technique- avoid scatter and improve contrast
- Intrinsically poor contrast- mostly give soft tissue
- Increased chance of motion arteface
- Exposre during expiratory pause
What radiographic considerations are there for the abdomen?
- Low kV, high mAs technique- avoid scatter and improve contrast
- Intrinsically poor contrast- mostly give soft tissue
- Increased chance of motion arteface
- Exposre during expiratory pause
What radiographic considerations are there for the abdomen?
- Low kV, high mAs technique- avoid scatter and improve contrast
- Intrinsically poor contrast- mostly give soft tissue
- Increased chance of motion arteface
- Exposre during expiratory pause
When is contrast indicated?
- Helpful for urinary tract studies
- Rarely useful in GI tract studies
- Essential for abdominal CT
- What happens is barium enters body cavities?
- What can it therefore be used for?
- Severe granulomatous inflammation
- GIT, urinary, IV and myelography
Why should US be done after radiography?
Gel artefact
What are blind spots in the abdomen?
- Organs within pelvic canal
- Vascular malformations
- Ectopic ureters
What are the rontgen radiological signs?
- Number
- Size
- Shape- margination
- Opacity
- Location
What are the following opacities?
What does the following radiograph show?
Renomegaly- mass effect
The following radiograph shows mass effect
What is the disease?
Acute pancreatitis
What does the following radiograph show?
Pyometra
- What is dystrophic mineralisation secondary to?
- What can cause this?
- How do the lesions appear?
- Tissue damage
- Adrenal- cats, Fat necrosis, tumours/abscesses
- Focal lesions
Also- urinary calculi, ingesta, osseous neoplasia
- What causes metastatic mineralisation?
- What is it secondary to?
- What is commonly mineralised?
- hypercalcaemia
- Toxic, uraemia, paraneoplastic
- Mineralisation of gastric mucosa, aortic wall etc
What causes loss of serosal detail of the abdomen?
- Lack of fat
- Peritoneal fluid
- Carcinomatosis/sarcomatosis
- Visceral crowding
- Peritonitis
- Brown fat/young animal
What can cause a pneumoperitoneum?
- Post surgery- upto 4 weeks
- Ruptured GIT- septic abdomen
- Penetrating trauma
What does the following radiograph show?
Pneumoperitoneum
* Increased contrast between gas and soft tissue
* Highlighting of serosal surface of organ
* Gas bubbles that do not conform to GIT
* Usually in conjunction with loss of serosal detail
Describe how to do the gastric axis?
- Fix a point in the middle of the fundus
- Draw a line to middle of pylorus
- Should be parallel to the last rib or perpendicular to the spine
How can hepatomegaly be identified on a radiograph?
Generalised
* Round margins
* Extending further caudal to the costal arch
* Caudally displaced gastric axis
Focal
* Mass effect
What can cause hepatomegaly?
Generalised or focal
Generalised
* Nodular hyperplasia
* Lymphoma
* Diffuse mets
* Acute hepatitis
* Metabolic hepatopathy
Focal
* Neoplasia
* Other mass
What can cause microhepatia?
Vascular
* PSS or
* Primary portal vein hypoplasia
Inflammatory
* Chronic hepatitis- fibrosis/cirrhosis
How should a spleen appear normally on radiographs?
Tail- flat triangle just caudal to liver ventrally- mobile
Head- flat triangle on the left- superimposing the kidney
Body- connects both often not visible
- What can cause splenic masses?
- What can cause generalised splenomegaly
- Neoplasia (haemangiosarcoma), haematoma, nodular hyperplasia
- Sedation/GA, infiltration (lymphoma), Inflammation
What is contained in the retroperitoneum?
Contains:
* Kidneys
* Ureters
* Bladder neck
* Great vessels
* Adrenal glands
* Lymph nodes
* Prostate
When are adrenal glands likely to be visible?
Not normally
* May mineralise in old cats
Mineralisation in dogs is assocaited with neoplasia
What mass effect do adrenal masses cause?
Displace kidney ventrally and/or laterally
Adenoma, carcinoma
What are the different peritoneal and retroperitoneal lympg nodes?
Peritoneal
* Gastric
* Pancreaticoduodenal
* Splenic
* Jejunal
* Colic
Retroperitoneal
* Para-aortic
* Medial iliac
* Internal iliac
* Sacral
Not normally visible on radiograph
