Thrall chapter 15 MRI and CT features of canine and feline spinal disease Flashcards
1) What is the anatomical structure labelled ‘1’?
a) Interarcuate ligament
b) Dorsal longitudinal ligament
c) Intercapital ligament
d) Ligamentum flavum
c
meningiovertebral ligament on top of the dorsal longitudinal ligament, the dorsal ligament is thickest in the c spine (more lateralised extrusions here)
2) Which structure reduces the likelihood of a dorsal disc protrusion between T2-T11
a) Interarcuate ligament
b) Dorsal longitudinal ligament
c) Intercapital ligament
d) Ligamentum flavum
c
3) What type of joints are the articular process joints of the vertebrae?
a) Synarthrodial
b) Amphiarthroidal
c) Diarthrodial
d) Cartilaginous
C
Define synarthroidal (type of joint)
In fibrous joints (synarthrodial joint) the bones are joined by fibrous tissue, namely dense fibrous connective tissue, and no joint cavity is present. The amount of movement allowed depends on the length of the connective tissue fibers uniting the bones.
- a fibrous joint
Define Amphiarthroidal
An amphiarthrosis is a joint that has limited mobility. An example of this type of joint is the cartilaginous joint that unites the bodies of adjacent vertebrae. Filling the gap between the vertebrae is a thick pad of fibrocartilage called an intervertebral disc
A cartilaginous joint
Define Diarthrodial
A diarthrosis joint is a freely moving joint characterized by its mobility and joint cavity within a synovial membrane encased in the joint capsule.
5) Why is the normal nucleus pulposus hyperintense on T2w images?
a) Because of the short T2 relaxation time of water in the nucleus
b) Because of the long T2 relaxation time of water in the nucleus
c) Because of the short TE and TR times
d) Rotation of water occurs near the Larmor frequency
b, fat is closer to the Larmor frequency
6) What percentage of dachshunds have vertebral transitional anomalies?
a) 5%
b) 10%
c) 20%
d) 30%
b
7) In chondrodystrophic dogs, acute disc herniation can lead to what CT appearance? (could be more than one)
a) Hypoattenuating material causing cord compression.
b) Diffuse less hyperattenuating (apx 60HU) less severe cord compression
c) Hyperattenuating (700HU) herniated disc material
d) A large focal amount of markedly hyperattenuating disc material (200HU) compressing the spinal cord
b,d (c is chronic due to further mineralization)
8) Epidural haemorrhage associated with disc extrusion is more common in which region?
a) Caudal Cervical
b) Cranial Thoracic
c) Thoracolumbar junction
d) Caudal Lumbar
d
9) Meningeal contrast adjacent to extruded extradural disc material occurs in what percentage of patients?
a) 40%
b) 25%
c) 60%
d) 15%
A
contrast enhancement of the compressive extradural disc material occurs in approximately 50% of dogs with disc extrusion
10) Which of the following is not a characteristic of lumbosacral stenosis
a) Intervertebral disc degeneration and protrusion
b) Hypertrophy of the articular process joint capsule and interarcuate ligament
c) Bone proliferation of the dorsal vertebral bodies
d) Vertebral subluxation
c- bone proliferation of the vertebral bodies is not correct, bone proliferation of the articular processes and vertebral end plates is correct
11) What type of disc disease is shown in the images below?
a) Acute compressive hydrated nucleus pulposus extrusion
b) Acute non-compressive nucleus pulposus extrusion
c) Hansen type II IVDD
d) Hansen type I IVDD
a
12) Which of these is not a prognostic factor used to assess the likelihood of a successful outcome in dogs with ANNPE?
a) Severity of neurological signs at presentation
b) Intramedullary contrast enhancement over the affected site
c) Percentage cross-sectional area of the intramedullary lesion on T2W images
d) Presence of intramedullary haemorrhage
b 33% of dogs with ANNPE have unsuccessful outcomes
13) From the paper by Bonelli et al, 2021 which of the following is incorrect regarding their findings in dogs with osseous associated cervical spondylomyelopathy?
a) Intervertebral disc degeneration was seen in 80% of dogs
b) Dogs with multiple sites of spinal cord compression were more likely to have severe spinal cord compression
c) There was a weak correlation between neurologic grade and severity of spinal cord compression and the number of affected sites
d) It more commonly affected female giant and large breed dogs.
d, males more affected.
14) In cats, what is the only reported cause of ischaemic myelopathy?
a) Thromboembolism
b) Fibrocartilaginous embolism
c) Neoplastic embolism
d) Septic embolism
B
1) Which of the following is false regarding subarachnoid diverticulae?
a) Most commonly dorsal or dorsolaterally located
b) Rottweilers are likely predisposed to thoracolumbar diverticula
c) Pugs have a high incidence of subarachnoid diverticula
d) The most common locations are cranial cervical or caudal thoracic
1) B- cervical in rottweilers
2) Which two categories of spinal dermoid sinuses are associated with neurological signs?
a) Type II: more superficial tract with deep fibrous strand connecting to the supraspinous or nuchal ligament
b) Type III: superficial tract with no connection to the supraspinous or nuchal ligament
c) Type IV: deep tract that extends to the supraspinous or nuchal ligament and continues deeper as a fibrous strand that connects to the dura mater
d) Type VI: deep tract that extends to the supraspinous or nuchal ligament and continues deeper as a fibrous strand that connects to the dura mater
C,D
3) Intramedullary spinal tumours are usually what type (can be more than one)?
a) Nerve sheath tumours
b) Astrocytomas
c) Meningiomas
d) Ependymomas
3) B,D or lymphoma or mets
4) In cats which is the most common intradural extramedullary neoplasia?
a) Lymphosarcoma
b) Meningioma
c) Peripheral nerve sheath tumour
d) Mast cell tumour
A
it is also the most common extradural tumour in cats
5) Which is the most likely location of this mass?
a) Extradural
b) Intradural- extramedullary
c) Intramedullary
B
6) According to cordle et al., 2023 which of the following is true?
a) MRI features can predict the onset of myelomalacia after acute intervertebral disc extrusion
b) MRI features can support a diagnosis of progressive myelomalacia in dogs with clinical evidence of the disease
c) Length of T2W hyperintense spinal cord change and HASTE signal loss were not significantly associated with clinically evident progressive myelomalacia
6) B. c is the opposite and it is statistically significant.
7) In what percentage of patients with FCE are no changes seen on MRI?
a) 15%
b) 80%
c) 50%
d) 20%
D
8) A lesion length to vertebral length ratio greater than XX has a sensitivity of 100% in predicting a poor clinical outcome for cases of ischaemic myelopathy?
a) 2
b) 2.5
c) 1.5
d) 1.8
A
true or false, in cases with disc extrusion and extensive epidural haemorrhage, contrast enhancement of the haemorrhage is uncommon?
False: Contrast enhancement of epidural hemorrhage is common, although it is not associated histopathologically with actual inflammation. In some dogs, these secondary epidural changes can mask the extruded disc material. Altogether, these features can cause erroneous diagnosis of a tumor, and this variability needs to be taken into account when interpreting MR images in dogs with acute neurologic presentation.
Changes in signal intensity of the paraspinal muscles can be seen in dogs with disc extrusion. what causes this?
patchy T2W/short tau inversion recovery (STIR) hyperintensities, and T1W hypointensities with variable contrast enhancement. They correlate with areas of muscle fiber degeneration, edema, inflammation, and necrosis.
in dogs with IVDE Areas of intramedullary T2 hyperintensity that exceed the length of XXX on sagittal images have been associated with a poor outcome in approximately 50% of patients
L2
This feature has been reported to be a better predictor of poor outcome than loss of deep pain perception, and it is independent from the severity of neurologic signs at presentation.
Tarlov cysts originate from
a) close to the ventral nerve root and ganglion sheath
b) from the dorsal nerve root and ganglion sheath
c) from the articular process joints
d) from the intervertebral disc
B
from the dorsal nerve root and ganglion sheath, close to the point where the pia and arachnoid membrane differentiate into endoneurium and perineurium
they are extradural lesions filled with CSF and contain neural structures pertaining to the nerve root and ganglion
are dermoid cysts and sinuses or epidermoid cysts and sinuses more heterogeneous on mri?
Dermoid cysts and sinuses differ from epidermoid cysts because the dermoid cyst contains other features of skin, such as sweat glands, hair follicles, and sebaceous glands. epidermoid cysts usually o ly contain squamous epithelium (radiopaedia)
which term is preferred?
a) synovial cyst
b) articular process cyst
c) ganglion cyst
B as although they are different, they cannot be distinguished based on imaging alone
what are the t1, t2 and GRE characteristics of myelomalacia?
t2 hyper, t1 iso (sometimes hypo) can have signal voids on t2 showing haemorrhage
regarding ascending/ descending myelomalacia, A length of CSF signal attenuation on HASTE/SSFSE pulse sequences (“T2-myelogram”) >XXX times the length of L2 vertebral body has also been reported as a predictive MRI criterion
7.4
Studies have suggested that in dogs with thoracolumbar disc herniation, a longitudinal extent of spinal cord parenchyma T2W hyperintensity higher than 4.5 to 6 times the length of L2 vertebral body could be a predictor of developing ascending/descending myelomalacia
Another recent study found that the length of parenchymal T2 hyperintensity was not a useful predictor for future development of myelomalacia in dogs with severe neurologic deficits who are not exhibiting clinical signs of myelomalacia. Absence of T2W spinal cord hyperintensity, however, does not rule out future development of myelomalacia particularly if imaging occurs less than 24 hours after onset of paraplegia.
. both are in the book.
what are the two most common intradural extramedullary tumours?
meningioma, nerve sheath tumour
which are the most common extradural tumours in dogs
osteosarcoma, chondrosarcoma
which location are nephroblastomas most commonly?
a) extradural
b) intradural extramedullary
c) intramedullary
d) l4-7
e) T10-L2
f)l2-l4
B, E It is thought that the tumor arises from ectopic embryonic remnants of renal tissue. A single mass is usually present, although there are rare reports of intraspinal metastases the tumour can invade the spinal cord and appear intrmedullary
true or false, ependymomas are the most common intramedullary spinal cord tumour in dogs?
true. followed by astrocytoma, and less commonly nephroblastoma, chordoma, oligodendroglioma, and teratoma
astrocytomas more common in cats (but very rare) and more common in cervical spine. cats- lymphoma!
the three most common spinal tumours that can involve several compartments of the vertebral canal are
histiocytes sarcoma, lymphoma, haemangiosarcoma
Histiocytes are a category of leukocytes that occur in many tissues throughout the body. They are derived from stem cell precursors and differentiate into cells of the monocyte/macrophage lineage or dendritic cell lineage
Histiocytic sarcoma is due to neoplastic transformation of interstitial dendritic cells, with the exception of a hematophagocytic variant, which occurs within the splenic red pulp and arises from macrophages
