Special Q13-19

Question 1

What is Cauda-Equina syndrome?

Answer 1

Serious neurological condition caused by damage/compression of the cauda equina, resulting in acute loss of function of the lumbar plexus.

Question 2

Causes of Cauda Equina Syndrome:

Answer 2

Lumbosacral stenosis, narrowing of the vertebral canal at the level of the lumbosacral joint. It is most often caused by:
Degenerative changes to the intervertebral disc
Arthritis of the joints
Abnormal proliferation of the ligaments

Question 3

Symptoms of Cauda Equina Syndrome:

Answer 3

Pain in the lumbo-sacral area
Hind leg incoordination or lameness
Urinary and fecal incontinence

Question 5

Radiographic features of Cauda Equina Syndrome:

Answer 5

Invertebral disc diseases:
* Bulging disc
* Broad herniation of disc
* Focal herniation, protrusion and extrusion
* Mineralized displacement fragments
* OCD
* Discospondilitis

Question 5

What is lumbosacral transitional vertebrae?

Answer 5

Vertebrae with characteristics of both lumbar and sacral vertebrae.
Occur between L7 and S1.
May lead to scoliosis and may protrude lumbosacral disc degeneration.

Question 6

What is sacralisation?

Answer 6

When a lumbar vertebrae has a sacral wing instead of a transverse process, may also articulate with the ileum

Question 7

What is myelography?

Answer 7

Radiography of the spinal cord after injection of an iodine-based contrast media into the subarachnoid space.

Question 8

Describe the technique for myelography:

Answer 8

Water-soluble, iodine based contrast media (non-ionic with low osmolarity) is injected. Excreted by kidneys within 48 hours.
Dose: 0.3 ml/kg as regional dose, 0.45 ml/kg as whole-spine dose.
* Sternal or lateral recumbency with head flexed ventrally
* 22 gauge needle
* Cisternal or lumbar puncture site
* Aspiration to confirm location (cerebrospinal fluid)

Question 9

Cranial/ cervical myelography is done by:

Answer 9

Contrast media injected through the atlantooccipital space (cisterna magna).

Question 10

Caudal/ lumbar myelography is done by:

Answer 10

Contrast media injected between L5-L6

Question 11

Who could benefit a myelography?

Answer 11

Confirming spinal lesions
Define the extent of a lesion
Finding a lesion
Identifying patients likely to benefit from surgery

Question 12

Classification of myelographic lesions:

Answer 12

1. Extradural: invertebral disc location
2. Intradural-extramedullary: neoplasia or granuloma
3. Intramedullary swelling: spinal cord oedema, neoplasia or ischemic myelopathy
4. Intramedullary opacification: myelomalacia, hematonyelia, myelitis, meningitis

Question 13

How to take a radiographic picture of the chest?

Answer 13

Beam centred at the caudal edge of scapula/cardiac silhouette
Picture taken during inspiration, so lungs are filled with air
Picture taken from the neck to the last rib
LL, VD, DV - always minimum 2 views
(standing if animal is in distress or there is suspected fluid in the thorax).

Question 14

Where is the mediastinum?

Answer 14

= Space between the pleural sacs
Surrounded by ventral chest wall, the lungs to the sides and the spine dorsally. Extends from the sternum ventrally to the vertebral column dorsally.
Normally not visible.

Question 15

Pathology of the mediastinum:

Answer 15

Pneumomediastinum: structures (vessels) are normally not visible as they contrast with air
Mediastinal masses: middle, cranio-ventral/dorsal or caudo-ventral/dorsal masses displace the trachea and push the lungs
Mediastinal fluid: result of ruptured esophagus, mediastinitis, congestive heart failure

Question 16

How to take picture of the trachea?

Answer 16

Picture of neck and thorax.
Radiolucent tube running ventrally parallel to the cervical spine (LL) to above the caudal end of the heart where it bifurcates into bronchus.
LL is the standard view.

Question 17

Pathology of the trachea:

Answer 17

Tracheal displacement (VD/DV view).
Wall thickening/increased mineralization (increased radiopacity)
Tracheitis (decrease in tracheal lumen)
Tracheal collapse/narrowing
Rupture/obstruction
Congenital hypoplasia (brachyocephalic breeds)

Question 18

How do take radiogram of the esophagus?

Answer 18

Laterolateral view
Contrast media:
* Barium paste - neoplasia
* Barium liquid - does not adhere to the wall
* Aqueous iodine solutions - if perforation is suspected, non-toxic

Question 19

Pathology of the esophagus:

Answer 19

Dilation: localized or generalized (megaoesophagus)
Esophagitis - thickening of the wall
Foreign bodies - blocking thoracic inglet
Compression
Diverticulum - outpouching
Esophageal narrowing
Neoplasia
Fistula, perforation, parasites

Question 20

Anatomy of lungs:

Answer 20

Right lung: cranial, middle, caudal and accessory lobes
Left lung: cranial, middle, caudal lobes
The only structures normally visible are pulmonary blood vessels
Lung parenchyma is better visible during expiration
VD/DV view
LL view = good for visualizing fluid accumulation

Question 21

Pathology of lungs:

Answer 21

Changes in opacity
- Increased: bronchitis, bronchial calcification, bronchial oedema
- Decreased: emphysema
Changes in size: pneumonia, pulmonary oedema, pulmonary masses, emphysema
Changes in shape: not triangular - masses, inflammation
Other: Pneumothorax, pneumohydrothorax

Question 22

What are the 4 main lung patterns?

Answer 22

Generally characterised by increased opacity.
1) Alveolar: air replaced by fluid or neoplastic cells. Patchy or diffuse increase in radiopacity and radiolucent lines.
2) Interstitial: general loss of contrast.
- Linear: thickening, fluid or cellular infiltrate
- Nodular: multiple nodules. Small, circular soft tissue opacities
3) Bronchial: thickening and increasing of bronchial walls, secondary to chronic inflammation.
- ‘‘donuts’’ and longitudinal as ‘‘tram lines’’
4) Vascular: change of appearance in blood vessels
- Hypervascularization: increased opacity
- Hypovascularization: periphery is more radiolucent

Question 23

Radiograph of the heart:

Answer 23

LL and DV in lateral and sternal recumbency
DV: Heart is located in left hemithorax.
Include entire thorax
Beam centre at caudal edge of scapula
Can be used contrast medium

Question 24

Evaluation of the heart:

Answer 24

Presence of abnormalities on cardiac silhouette: size, shape, location, opacity and margination
Presence of cardiomegaly
Alteration in size of pulmonary vessels
Evidence of left-sided failure (oedema) and/or right-sided failure (pleural effusion, hepatomegaly)
Enlargement of descending aorta, heart-base region, vena cava caudalis or lung artery

Question 25

Pathologies of the heart:

Answer 25

Cardiomegaly (LL)
Right heart failure: right ventricle enlargement, v. cava distension, pleural effusion, ascites
Left heart failure: pulmonary vein dilation, pulmonary oedema, blurred vascular structures
Pericardial effusion: enlarged cardiac shadow

Question 26

Cardiac vessels:

Answer 26

Pathology: dilation
Vena cava caudalis: VD and left LL
- LL: extend from the caudal border of the cardiac silhouette towards the right crus of the diaphragm, width usually the same as aorta
Aorta: LL and DV
- LL: aortic arch visible craniodorsally to the cardiac silhouette, diameter is height of a thoracic vertebral body
- DV: the aortic arch is visible cranial to the left of the cardiac silhouette

Question 27

Pulmonary vessels:

Answer 27

Changes in size: congestive heart failure etc.
- Increased: severe chronic lung disease, hypervolemia
- Decreased: hypovolemia, shock, dehydration