RD spine Formatted Flashcards
- A 19 yo man with lower back pain and no other history. MRI shows 25mm long, 2mm wide lesion in conus (LAS – 15 x 2mm). Bright on T2, iso on T1 (LAS – fluid-filled). Most likely:
a. Ventricular terminalis
b. Syrinx
c. Myelomeningocele
d. Meningioma
e. Astrocytoma
f. Ependymoma
g. Haemangioblastoma
a. Ventricular terminalis T if 15mm, likely F if 25mm though; asymptomatic; Mild cystic dilatation of distal central spinal cord canal without cord signal abnormality or enhancement; size 2-4mm transverse, rarely exceeds 2cm in length; no septation;
b. Syrinx = T = fluid-intensity intramedullary cord cleft; can cause pain (StatDx); should be T1 hypointense though; right age group for primary syrinx; most common location is lower cervical cord
- A 19 yo man with lower back pain and no other history. MRI shows 25mm long, 2mm wide lesion in conus (LAS – 15 x 2mm). Bright on T2, iso on T1 (LAS – fluid-filled). Most likely:
a. Ventricular terminalis T if 15mm, likely F if 25mm though; asymptomatic; Mild cystic dilatation of distal central spinal cord canal without cord signal abnormality or enhancement; size 2-4mm transverse, rarely exceeds 2cm in length; no septation;
b. Syrinx = T = fluid-intensity intramedullary cord cleft; can cause pain (StatDx); should be T1 hypointense though; right age group for primary syrinx; most common location is lower cervical cord
c. Myelomeningocele F
d. Meningioma F extramedullary
e. Astrocytoma F T1 hypo to iso, T2 mildly hyper, eccentric location, usually in thoracic cord; cystic tumours should have cord expansion.
f. Ependymoma F expect haemosiderin cap and satellite cysts or syrinx; can occur at conus; usually older age (35-45 yo);
g. Haemangioblastoma F often cyst with mural nodule with associated syrinx, but not all fluid intensity (Lin p310) If neoplastic should have surrounding abnormal T2 signal.
Haemangioblastoma in spine. which is true
a. if multiple a/w with Osler weber rendu
b. less than 1 % of spinal tumours
c.c most common in thoracic spine
A = F (assoc/ w/ VHL, although 75% are sporadic)
B = F (1-6% of spinal cord neoplasms)
C = T thoracic (50%) > cervical (40%)
Random facz
-Haemangioblastomas are benign vascular lesions that do not undergo malignant degeneration. They are WHO grade 1 in the 5th Edition (2021)
-most common location is the thoracic cord (50%).
-80% solitary, when multiple then think VHL
-associated tumour cyst or syrinx is common (50-100%)
- Regarding the lumbar spine, which is LEAST correct.
a. Annular tears are typically secondary to trauma
.b. Focal herniation refers to <25% disc circumference.
c. Broad based herniation refers to 25-50% disc circumference.
d. Far lateral disc protrusion at L3/4 impinges the L3 nerve root.
e. Posterolateral disc protrusion at L3/4 impinges the L4 nerve root.
a. Annular tears are typically secondary to trauma. ?F Disruption of concentric collagenous fibers comprising the anulus fibrosus. Abnormal signal focus (HIZ) at posterior disc margin on MRI. Direct association with disc degeneration, often due to repetitive trauma.
RY* 2014 nomeclature update
- Annular fissure should be used because secondary to degeneration, annular tear is no longer a correct term (implies trauma related).
- Herniation is <25%
- Asymmetrical bulge >25%
- Bulge is circumferential.
- Broad based not part of terminology
https://www.thespinejournalonline.com/article/S1529-9430(14)00409-4/fulltext
Least supportive of EG in kid with back pain and loss of vertebral body height at T7
a. mass.
b. involvement of posterior elements.
c. wedge shaped compression.
*LW: Preferred answer is B:
A. Small Paraspinal soft tissue has common.
B. Involvement of posterior elements is rare / excitedly unusual / uncommon finding. Thus favoured answer being least supportive.
C. Vertebral plana is a common feature, while wedge compression or uneven lateral compression is enchanted in early stages.
(radiographics 1992)
C = F? = LCH causes collapse of vertebral body to thin disc; adjacent discs normal (although this is usually only seen in the textbooks as per Dr Earwaker)
A = T = Small paraspinal/epidural soft tissue component common
B = T? = posterior element more common in cervical spine; Pocket Rad Spine says posterior elements involved rarely (however Dr Earwaker disagrees)
C = F? = LCH causes collapse of vertebral body to thin disc; adjacent discs normal (although this is usually only seen in the textbooks as per Dr Earwaker)
1) Regarding lumbar discs, which is the most correct:
i) Annular tear is secondary to trauma
ii) Focal herniation < 25%
iii) Broad-based herniation >50%
iv) Far lateral disc at L4/5 level affects L5 nerve
v) Posterolateral disc at L3/4 level affects L3 nerve
ii) Focal herniation < 25% T
1) Regarding lumbar discs, which is the most correct
:i) Annular tear is secondary to trauma ?F Disruption of concentric collagenous fibers comprising the anulus fibrosus. Abnormal signal focus (HIZ) at posterior disc margin on MRI. Direct association with disc degeneration, often due to repetitive trauma
.ii) Focal herniation < 25% T
iii) Broad-based herniation >50% F 25-50%
iv) Far lateral disc at L4/5 level affects L5 nerve F may affect the L4 exiting root
v) Posterolateral disc at L3/4 level affects L3 nerve F will usually affect the descending L4 rootSee details in answer for April 2011
2) Chance fracture following MVA. Most relevant:
i) Almost universally has neurological deficit
ii) Vertebral disc distraction
iii) Spinal cord injury
iv) Flexion compression fracture of middle column
iii) Spinal cord injury T can have cord contusion
2) Chance fracture following MVA. Most relevant:
i) Almost universally has neurological deficit F StatDx - Neurologic injury may be present; more commonly have abdominal visceral injury
ii) Vertebral disc distraction T can occur
iii) Spinal cord injury T can have cord contusion
iv) Flexion compression fracture of middle column F
Compression injury of anterior column with distraction of middle & posterior columns (StatDx)
• Acute forward flexion of the spine across a restraining lap seat-belt during sudden deceleration causes the spine above the belt to be pushed forward & distracted from the lower, fixed part of the spine
o Distraction of middle-posterior elements/ligaments; anterior compression of vertebral body
random facz
- high association with duodenal and pancreas injury
-most commonly occurs about the upper lumbar spine (with the thoracolumbar junction accounting for ~50% of cases)
-The anterior and middle columns fail in compression, and the posterior column fails in distraction
3) Dwarf. Low back pain radiating down both legs. Most likely cause:
i) Overexaggerated lordosis of sacrum
ii) Short pedicles
iii) Scalloping of vertebral bodies
iv) Scoliosis
v) Sacrosciatic action
ii) Short pedicles T combined with decreasing interpedicular distance causes spinal canal stenosis, with superimposed bony degenerative disease (StatDx)
TB spondylitis/disciti. which is true
a. always find TB lung changes on CXR
b. cold abscess central high T1, low T2
c. noncontiguous involvement less likely than pyogenic
d. disc spared until late.
e. anterior sub ligamentous spread is more common in bacterial osteomyelitis /discitis
D = T = relative preservation of disc height in TB
A = F = Concomitant pulmonary tuberculosis in about 10% of patients (StatDx); about 50% of patients have obvious pulmonary disease (Neuro Req p543)
B = F = ‘cold abscess’ = a chronic abscess of slow formation and with little evidence of inflammation; T1 hypointense, T2 hyperintense, peripherally enhancing
C = F = spread of infection can occur beneath the ALL, therefore TB is more likely to have contiguous involvement
D = T = relative preservation of disc height in TBE = F
Random Facz
-spine is the most frequent location of musculoskeletal tuberculosis.
-likes anterior portion of vertebral body.
- Regarding spinal trauma is FALSE?
a. About 5% of patients with a primary spinal injury have another non-contiguous vertebral injury.
b. Fracture through the disc occurs in DISH
c. Cervical flexion tear-drop type fractures are associated with ventral cord injury
d. Chance fractures are almost universially associated with neurological injury
e. A limbus vertebra occurs most often on the anterior-superior margin of a mid lumbar vertebra
d) Chance fractures are almost universally associated with neurological injury F can occur, but visceral injury more common
4) Regarding spinal trauma is FALSE?
a) About 5% of patients with a primary spinal injury have another non-contiguous vertebral injury. T?
b) Fracture through the disc occurs in DISH T can occur, but are more common in the vertebral body than the disc (unlike in AS) – AJR 2009
c) Cervical flexion tear-drop type fractures are associated with ventral cord injury T
d) Chance fractures are almost universally associated with neurological injury F can occur, but visceral injury more common
e) A limbus vertebra occurs most often on the anterior-superior margin of a mid lumbar vertebra T Intraosseous disc penetration at junction of cartilaginous endplate, developing osseous rim apophysis → Small corticated bone fragment matching osseous defect of anterosuperior vertebral margin; Mid-lumbar > mid-cervical location. Anterior»_space; posterior.
chordoma least likely.
a. typically presents before age 30
b. destruction
c. soft tissue mass
d. ends of axial skeleton
e. spinal cord met is a recognised complication
A = F (rare in patients < 30 yrs; < 5% of chordomas present in childhood; peak incidence 5th-6th decade)
E = F can get intradural drop metastases (J Clin Neurosci. 2009 Aug;16(8):1105-7, from PAH) & bony (e.g. vertebral) metastases, but nothing about spinal cord metastases (may be most false??
)A = F (rare in patients < 30 yrs; < 5% of chordomas present in childhood; peak incidence 5th-6th decade)
B = T (lytic, destructive lesion – may involve disc, contiguous vertebrae, epidural space, etc.)
C = T
D = T (sacrum > clivus > vertebral body)
E = F can get intradural drop metastases (J Clin Neurosci. 2009 Aug;16(8):1105-7, from PAH) & bony (e.g. vertebral) metastases, but nothing about spinal cord metastases (may be most false??)
40 yo male. destructive sacral lesion. least likely (probably most false??)
a. chrodoma
b. plasmacytoma
c. met
d. osteoblastoma
e. chondrosarcoma
*LW: Radprimer states most likely causes of solitary sacral mass in adult are: GCT, Chordoma, Plasmacytoma.
D = T (lytic & expansile – ‘aggressive osteoblastoma’ can cause cortical breakthrough & have wide zone of transition though!)
A = T (most common primary malignancy)
B = T
C = T
D = T (lytic & expansile – ‘aggressive osteoblastoma’ can cause cortical breakthrough & have wide zone of transition though!)
E = T (5% occur in spine & sacrum) Osteoblastoma would be least destructive, but is more common than chondrosarcoma in sacrum.
- yo male, previously well. Sees GP with worsening back pain. Physical exam and laboratory tests are unremarkable. Plain radiograph of spine shows sclerotic T8 vertebra without loss of height. MOST APPROPRIATE subsequent investigation?
a. Radionuclide bone scan
b. MRI spine
c. Skeletal survey
d. CT thoracic spine
e. No further Ix required
a. Radionuclide bone scan T most likely prostate mets
- 34yo male with neck pain for last 2y. MRI shows intraspinal mass at cervical level. Which of following would favour an astrocytoma over Ependymoma
a. Well defined Intramedullary mass
b. Ill defined Intramedullary mass
c. Presence of hemorrhage
d. Homogeneous enhancement
e. Multiple intracranial meningomas
b. Ill defined Intramedullary mass T astrocytoma more likely to have ill-defined borders & spread over several vertebral levels
- 34yo male with neck pain for last 2y. MRI shows intraspinal mass at cervical level. Which of following would favour an astrocytoma over Ependymoma
a. Well defined Intramedullary mass F ependymoma more likely to be well defined.
b. Ill defined Intramedullary mass T astrocytoma more likely to have ill-defined borders & spread over several vertebral levels
c. Presence of hemorrhage F rare in astrocytoma; haemosiderin cap common in ependymoma
d. Homogeneous enhancement F heterogeneous in astrocytoma, homogeneous in ependymoma
e. Multiple intracranial meningomas suggests NF-2, i.e. ependymoma > astrocytoma
- Astrocytoma - patchy irregular Gd-enhancement on MR
Ependydmoma enhance homogeneously in 84%.
Ganglioglioma - Patchy (65%, / no (15%) tumor enhancement
Ependymomas are more frequently hemorrhagic than astrocytomas, especially myxopapillary types at conus
ADB random facz
Ependymoma (adults)
-more common 60%
-older age by 10 years, 39 vs 29 for astro
-cervical most common, central location within cord
-haemorrhage cap
- smaller than astrocytoma, well circumscribed
- intense enhancement
-associate with NF2
Astrocytoma
- less common, younger than ependymoma
-larger ill-defined infiltrative
- patchy irregular enhancement
- uncommon haemorrhage
-eccentric in cord, thoracic cord
-assoc NF1
- 40yo man with 4/12 Hx increasing back pain. Plain films - destructive lesion of sacrum. CT shows soft tissue mass in sacrum, no calcification in it. MRI shows heterogeneous mass with areas of low signal on T1 and T2. MOST LIKELY?’
a. Chordoma
b. Plasmacytoma
c. Chondrosarcoma
d. Giant cell tumor of bone
e. Osteoblastoma
*LW: Radprimer states most likely causes of solitary sacral mass in adult are: GCT, Chordoma, Plasmacytoma.
d. Giant cell tumor of bone T? usually no ca++, lytic, heterogeneous due to haemorrhage, necrosis and fibrous tissue.; 2nd most common primary sacral tumour after chordoma; locally aggressive; 2nd-4th decade. Locally aggressive, eccentric; involves subchondral bone, may grow across SIJ. 5-10% are malignant.3.
40yo man with 4/12 Hx increasing back pain. Plain films - destructive lesion of sacrum. CT shows soft tissue mass in sacrum, no calcification in it. MRI shows heterogenelus mass with areas of low signal on T1 and T2. MOST LIKELY?
a. Chordoma ?F most common primary sacral malignancy; > 70% have intratumoural calcification (StatDx says peripheral calcification in MSK article & amorphous intratumoural calcification in Spine article!); T1 & T2 hetero; 70% in sacrum have T2 low signal foci of haemosiderin. Arise from notochordal rests, therefore always midline/paramedian in relation to spine. Most common primary sacral malignancy (excl. lymphoproliferative), mostly 4th-7th decades, 50-60% in sacrum (35% in clivus). Locally aggressive, amorphous calcifications, may cross SIJ
.b. Plasmacytoma F possible, but less likely; lytic, destructive lesions
c. Chondrosarcoma F will have chondroid matrix calcification; lytic lesion with assocd soft tissue mass and calcifications; adults.
d. Giant cell tumor of bone T? usually no ca++, lytic, heterogeneous due to haemorrhage, necrosis and fibrous tissue.; 2nd most common primary sacral tumour after chordoma; locally aggressive; 2nd-4th decade. Locally aggressive, eccentric; involves subchondral bone, may grow across SIJ. 5-10% are malignant.
e. Osteoblastoma F rare in sacrum; May be blastic (large osteoid osteoma) or expansile & lytic (similar to ABC). Tends involve the posterior vertebral elements.
- 12yo male with recent onset back pain. Plain film reveals approx 60% reduction of T7 vertebral body height. Which of following findings would make the Dx of EG UNLIKELY?
a. Involvement of other bones
b. Surrounding soft tissue swelling
c. Wedge-like vertebral body collapse
d. Involvement of the posterior elements
*LW: Favoured answer is involvement of posterior elements:
Radiographic states: EG can initially cause wedge like or uneven lateral compression of vertebral bodies, before developing complete vertebra plana.
Often multifocal
Commonly small para spinal soft tissue mass.
Involvement of posterior elements uncommon / destruction of posterior elements is atypical - hence most unlikely.
h. Wedge-like vertebral body collapse. = F = LCH causes Collapse of vertebral body to thin disc; adjacent discs normal4.
12yo male with recent onset back pain. Plain film reveals approx 60% reduction of T7 vertebral body height. Which of following findings would make the Dx of EG UNLIKELY?
f. Involvement of other bones T often multifocal
g. Surrounding soft tissue swelling T = Small paraspinal/epidural soft tissue component can occur
h. Wedge-like vertebral body collapse. = F = LCH causes Collapse of vertebral body to thin disc; adjacent discs normal
i. Involvement of the posterior elements ? F = typically spares the posterior elements (RG) ; posterior element more commonly involved in cervical spine (StatDx);
Dr Earwaker however has shown me a case involving the posterior elements, he indicates it’s not that rare
The radiographic characteristics of a typical spinal lesion consist of complete or incomplete collapse of the vertebral body; absence of an osteolytic area; preservation of pedicles, posterior elements, and adjacent disk spaces; absence of adjacent paravertebral soft-tissue shadow; and increased opacity in the collapsed body http://radiographics.rsna.org/content/28/4/1019.full.pdf
- 18yo female with persistent lower back pain and scoliosis. Plain film examination reports a sclerotic left T8 pedicle lesion with associated sclerosis. Which of the following is MOST LIKELY?
a. Osteoid osteoma
b. Fibrous dysplasia
c. Sclerotic met T8
d. Early-Paget’s disease
a. Osteoid osteoma
1.A young female has neck pain, dysarthria and diplopia. Non contrast CT brain and cervical spine both normal. The next most appropriate investigation is:
1.CT brain with contrast
2.MRI brain
3.Duplex ultrasound neck
4.DSA
5.LP
2.MRI brain - T - MR is the modality of choice (but should specify MRI + MRA?). MRI detects both the intramural thrombus and intimal flap that are characteristic of VAD. Hyperintensity of the vessel wall seen on T1 axial images is considered pathognomonic of VAD. MRA can identify abnormalities that are characteristic of the disturbed arterial flow seen in VAD. These include the presence of a pseudolumen and aneurysmal dilation of the artery. MRI and MRA are less sensitive than cerebral angiography for the detection of VAD, although they probably have equivalent specificity.
1.A young female has neck pain, dysarthria and diplopia. Non contrast CT brain and cervical spine both normal. The next most appropriate investigation is: (GC)
1.CT brain with contrast - F - possibly CTA (accessibility after hours).
2.MRI brain - T - MR is the modality of choice (but should specify MRI + MRA?). MRI detects both the intramural thrombus and intimal flap that are characteristic of VAD. Hyperintensity of the vessel wall seen on T1 axial images is considered pathognomonic of VAD. MRA can identify abnormalities that are characteristic of the disturbed arterial flow seen in VAD. These include the presence of a pseudolumen and aneurysmal dilation of the artery. MRI and MRA are less sensitive than cerebral angiography for the detection of VAD, although they probably have equivalent specificity.
3.Duplex ultrasound neck - F - demonstrates abnormal flow in 95% of patients with VAD; US signs specific to VAD (eg, segmental dilation of the vessel, eccentric channel) are detectable in only 20% of patients.
4.DSA - T - indicated when clinical suspicion is high but MRI/MRA has failed to isolate the lesion; characteristic angiographic finding in a dissected vertebral artery is the string or “string and pearl” appearance of the stenotic vessel lumen; also intimal flap / complete occlusion.
5.LP - F - patients with suspected SAH and a normal CT scan may undergo LP if VAD is not pursued by other imaging modalities. The typical presentation of VAD is a young person with severe occipital headache and posterior nuchal pain following a recent, relatively minor, head or neck injury. The trauma is generally from a trivial mechanism but is associated with some degree of cervical distortion.
Focal neurologic signs attributable to ischaemia of the brainstem / cerebellum ultimately develop in 85% of pts; however, a latent period as long as 3 days between onset of pain and development of CNS sx is not uncommon.
Symptoms of vertebral a. dissection include: Ipsilateral facial dysaesthesia (pain and numbness) - most common symptom Dysarthria or hoarseness (CN IX and X) Contralateral loss of pain and temperature sensation in the trunk and limbs Ipsilateral loss of taste (nucleus and tractus solitarius) Hiccups Vertigo Nausea and vomiting Diplopia or oscillopsia (image movement experienced with head motion) Dysphagia (CN IX and X) Disequilibrium Unilateral hearing loss [eMedicine; Craniocervical arterial dissection RG 2008
2.64 year old male presents with worsening back pain. Otherwise well. Normal examination. Sclerotic lesion T8 vertebral body without loss in height. The most appropriate next investigation is:
1.Skeletal survey
2.CT T-spine
3.MRI T-spine
4.Bone scan
5.No further investigation required at this stage
4.Bone scan - T - would evaluate if solitary / multifocal, and if active. 2.
64 year old male presents with worsening back pain. Otherwise well. Normal examination. Sclerotic lesion T8 vertebral body without loss in height. The most appropriate next investigation is: (GC)
1.Skeletal survey - F
2.CT T-spine - F - need to image whole spine, whereby MRI would give more information regarding discs etc. as other potential causes for back pain.
3.MRI T-spine - F - need to image whole spine.
4.Bone scan - T - would evaluate if solitary / multifocal, and if active.
5.No further investigation required at this stage - F - at least check PSA.
Bone tumours favouring vertebral bodies: CALL HOME Chordoma, ABC, Leukaemia, Lymphoma, Haemangioma, Osteoid osteoma/Osteoblastoma, Myeloma/Mets, EG/Ewing.
Ddx widespread sclerotic lesions: metastases - prostate, (breast), lung, bladder, pancreas, stomach, colon, carcinoid, brain Paget’s disease sarcoma myelofibrosis mastocytosis [Dahnert]
3.Which of the following is false regarding chordomas?
1.Spinal metastases
2.Destructive lesion with soft tissue
3.Less than 30 years old
4.Occurs in both ends of the spine
3.Less than 30 years old - F - can occur at any age, but mainly 30-70yo (mean 50yo). M>F 2:1. Can occur at < 30 years, but uncommon.
3.Which of the following is false regarding chordomas? (TW)
1.Spinal metastases - T - metastases (in 5-43%) to liver, lung, bone, regional lymph node, peritoneum, skin (late) heart. (if specify spinal CORD, then would be false)
2.Destructive lesion with soft tissue - T - lobulated tumor contained within pseudocapsule. Most frequent radiographic appearance of chordoma is that of a destructuve lesion of a vertebral body centered in the midline, with a large, associated soft tissue mass.
3.Less than 30 years old - F - can occur at any age, but mainly 30-70yo (mean 50yo). M>F 2:1. Can occur at < 30 years, but uncommon.
4.Occurs in both ends of the spine - T - 50% in sacrum, 35% in clivus, 15% in vertebrae. Chordoma is the most common primary malignant tumor of the spine in adults excluding lymphproliferative neoplasms. Originates from embryonic remnants of notochord / ectopi cordal foci. Histo - cords & clusters of large bubblelike vacuolated (physaliferous) cells.Key DDx = Chondrosarcoma (also T2 hyperintense)
4.Which of the following is more suggestive tuberculous rather than pyogenic infection of the spine?
1.Multifocal
2.Low signal on T1 and T2
3.Disc space narrowing
4.Subligamentous spread
5.Normal chest xray rules it out
4.Subligamentous spread - T - infection spreads beneath the ALL or PLL to adjacent vertebrae; may see skip lesions. Pyogenic infection spreads contiguously involving disc and subchondral bone; begins in disc margin in kids (highly vascularised); in adults begins in endplate with secondary disc invovlement.
4.Which of the following is more suggestive of tuberculous rather than pyogenic infection of the spine? (GC)
1.Multifocal - F - In TB there is typically more than one (up to 5-10) vertebrae involved due to subligamentous spread; upper lumber + lower thoracic (L1 most common). Pyogenic infection may involve multiple levels in 20% (esp. immunocompromised).
2.Low signal on T1 and T2 - F - non discriminating feature of spondylitis - low SI of marrow on T1, contrast enhancement of marrow +/- disc, high SI of disc (+/- marrow) on T2.
3.Disc space narrowing - F - relative preservation of disc space because TB lacks proteolytic enzymes; disc itself is preserved but fragmented (cf. rapid destruction in pyogenic infection).
4.Subligamentous spread - T - infection spreads beneath the ALL or PLL to adjacent vertebrae; may see skip lesions. Pyogenic infection spreads contiguously involving disc and subchondral bone; begins in disc margin in kids (highly vascularised); in adults begins in endplate with secondary disc invovlement.
5.Normal chest xray rules it out - F - no pulmonary lesions in 50%.
10.Contraindications MRI . which is false
1.PPM
2.clipped aneurysm
3.Stent
4.Spinal stimulator
5.Spinal rods
*AJL - Contraindications have probably changed since this question was written. Can look it up at mrisafety.com if unsure.
PPM - Need to check if it is MRI safe. Most modern ones are safe.
Clipped aneurism - Need to check that it is not magnetic, most modern clips are not magnetic.
Stent - Should be safe
Spinal stimulator - Need to check if MRI safe.
Spinal rods - safe.
Previous answer
5.Spinal rods - F - heating is relatively low. Generally orthopedic implants show no deflection within main magnetic field.
10.Contraindications MRI (TW)
1.PPM - T - absolute contraindication for MRI. Even in patients where PM has been removed, remaining pacer wires could act as an antenna and induce currents, causing cardiac fibrillation.
2.clipped aneurysm - T - the presence of some intracranial aneurysm clips is an absolute contra-indication to MRI. Clip motion may damage the vessel. Only MRI if definitely know clip is non-ferrous.
3.Stent - T - less false - depending on what stent. Coronary artery stents are largely MRI safe from what I can gather, as are aortic stents. Not sure about intracranial stents, or stents elsewhere - didn’t specify in answer.
4.Spinal stimulator - T - certain implated devices are contraindicated for MR inaging becuase they are either, magnetically, electrically, or mechanically activated (cochlear implants, tissue expanders, ocular prosthesis, dental implants, neurostimulators, bone growth timulators, implantable cardiac defibrillators, implantable drug infusion pumps)
5.Spinal rods - F - heating is relatively low. Generally orthopedic implants show no deflection within main magnetic field.
11.Paediatric C spine which is true:
1.Atlanto axial subluxation is less common than in adults
2.Anterior wedge of C3 is not a normal variant
3.Lateral displacement of lateral masses C1/2 by 6mm is a normal finding in a 4 year old
4.Injuries are more commonly lower cervical than upper
3.Lateral displacement of lateral masses C1/2 by 6mm is a normal finding in a 4 year old – T - Total offset (sum of both sides) of more than 6mm of the lateral masses of the atlas with respect to the odontoid is highly suggestive of rupture of the transverse ligament or avulsion of its attachments. (see below)
11.Paediatric C spine which is true: (TW)
1.Atlanto axial subluxation is less common than in adults – F - occurs 5x more common in children than adults
2.Anterior wedge of C3 is not a normal variant - F - normal variant, however age dependent: eg, anterior wedging in a 3yo at C5 is likely normal variant. However wedged body at C5 in an 8yo is likely pathologically compressed.
3.Lateral displacement of lateral masses C1/2 by 6mm is a normal finding in a 4 year old – T - Total offset (sum of both sides) of more than 6mm of the lateral masses of the atlas with respect to the odontoid is highly suggestive of rupture of the transverse ligament or avulsion of its attachments. (see below)
4.Injuries are more commonly lower cervical than upper – F - in patients under 9yo, almost all injures are to the occiput-C2 region (Imaging of Spinal Trauma in Children, Kuhns).
Above ans from: Differences between adult and paeds spinal injury (Spinal Trauma in Children, Paeds Radiol 2001)
Re: option 3. “Imaging in Pediatric Skeletal Trauma” K Johnson - “The lateral masses of C1 and C2 may be offset bilaterally in young children so that the lateral masses of C1 overhang those of C2 on the AP view, simulating a Jefferson burst fracture. This phenomenon is thought to be secondary to disparity in growth rate between the two vertebra and is most commonly seen at around 4y of age, but often up to 7y of age. Up to 6mm lateral displacement of the lateral masses of C1 relative to the odontoid is within normal limits under these circumstances. Physiological subluxation of C2/3 seen In 25 % children < 8 years. C3/4 15% note less than 3 mm, posterior line retains alignment.
12.Fatty marrow, most likely site:
1.Rib
2.Spine
3.Femoral diaphysis
4.Prox humerus
3.Femoral diaphysis Red or cellular marrow (RM) is hematopoietcally active.
Hematopoietically inactive yellow marrow (YM) is composed of fat cells.
RM signal iso- / slightly hyper to muscle T1 and T2. YM iso with subcutaneous fat T1, hyperintense to muscle on T2, and iso- / slightly lower than subcut fat.
Birth - marrow predominantly hematopoietically active cells. Orderly and predictable conversion - begins in appendicular/peripheral skeleton and progresses to the axial/central skeleton.
In long bones, marrow conversion first in diaphysis, then distal metaphyses, and finally proximal metaphyses.
Adult marrow pattern reached ~25y - at this time see red marrow in axial skeleton (skull, spine, sternum, flat bones) and prox ends of humeri and femurs), yellow marrow elsewhere. May see subchondral islands of red marrow in proximal humeral epiphyses.
The adult pattern is characterized by the presence of red marrow only in portions of the vertebrae, sternum, ribs, clavicles, scapulae, skull, and innominate bones and in the metaphyses of the femora and humeri.
13.Posterior scalloping, false:
1.Communicating hydrocephalus
2.Psoriasis
3.Achondroplasia
4.Neurofibromatosis
5.Ependymoma
2.Psoriasis - F
Posterior vertebral body scalloping
dural ectasia (NF, Marfan’s, Ehlers-Danlos),
syrinx,
spinal canal tumor,
congenital (achondroplasia, mucopolysaccharidoses, OI),
acromegaly