Files

T

Ross 9c86b32c3b .

2025-10-20 21:15:33 +01:00

24 KiB

Raw Permalink Blame History

title, docid, authors, breadcrumbs, category, documentVersionId, imageCount, lastUpdated, pageDescription, pageKeywords, pageTitle, enhancedTitle, type, references, breadcrumbs

title

docid

authors

breadcrumbs

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues
- Hint: Differentiate trauma vs. bony congenital variant - Soft tissue swelling usually evident in trauma - Cortication of bone indicates nonacute trauma - Os odontoideum thought to be nonunited fracture, not necessarily congenital variant
- Hint: Watch for mass adjacent to dens - Pannus from rheumatoid arthritis (RA): Dens eroded, no calcification - Seronegative spondyloarthropathy: Like RA, plus enthesophytes, joint fusion - Juvenile inflammatory arthropathy: Like adult RA or seronegative spondyloarthropathy - Usually involves multiple levels in cervical spine - Growth disturbance characteristic - Calcium pyrophosphate deposition disease (CPPD): Calcifications, cysts in bone - Infection: Usually involves disc space - Tuberculosis involves disc space later in course of infection - Tumor: Origin in bone, meninges, or cord
- Hint: Watch for heterogeneous high signal in bone marrow without cortical breakthrough - Myeloma - Lymphoma - Metastases
Helpful Clues for Common Diagnoses
- Bone Trauma - Odontoid fracture, C2 - Type I: Obliquely oriented through tip - Type II: Horizontally oriented through base - Type III: Really fracture of body; horizontally oriented, through body and below base of dens - Hangman's fracture, C2 - Hyperflexion or hyperextension, usually from motor vehicle accident - Traumatic spondylolisthesis of C2 - Fracture through C2 pedicles - Usually see focal kyphosis and anterolisthesis at C2-C3 - Effendi type I: Traumatic spondylolisthesis isolated - Effendi type II: Also disruption of C2-C3 disc - Effendi type III: Also disruption of C2-C3 facet joints - Burst fracture, C2 - Axial load injury - Extends through posterior cortex of vertebral body - Os odontoideum - Chronic nonunited fracture
- Congenital Bone and Ligament Abnormalities - May be multiple - May be isolated, detected as incidental finding in adulthood - Often cause adjacent premature degeneration - Trisomy 21 - Spinal stenosis - Instability occiput-C1 and C1-C2 - Unlike RA, no erosion of dens
- Arthritis - Osteoarthritis - Common at craniocervical junction - Involves synovial articulations: Facet joints, dens/C1 articulation - Dens and anterior arch of C1 develop osteophytes, sclerosis best seen on CT - May have prominent soft tissues posterior to dens but no erosions - Facet osteoarthritis at occiput-C1 or C1-C2 may develop large osteophytes, synovial cysts - Calcium pyrophosphate deposition disease - Mimics RA on MR, but subchondral bone plate not eroded - Calcifications visible on CT, radiographs - Rheumatoid arthritis - Calcification never present - Pannus heterogeneous signal intensity on MR - Low signal intensity areas on T2WI mimic crystals, calcification - Almost always see erosion of dens - Early erosion: Loss of subchondral bone plate - Late erosion: Pencilling of dens - Facet erosion: Atlantoaxial impaction - Craniocervical disease does not occur without peripheral disease (hands/feet)

References

Selected References

Images

Selected Images

$Axial bone CT shows small, bony density without cortical margins adjacent to the right condyle, consistent with a nondisplaced right occipital condyle avulsion fracture .$ Occipital Condyle Fracture Axial bone CT shows small, bony density without cortical margins adjacent to the right condyle, consistent with a nondisplaced right occipital condyle avulsion fracture .

$Axial bone CT shows severe comminuted fractures involving both the posterior and anterior arches of C1 . There is also an avulsion off of the medial aspect of the left C1 lateral mass at the insertion of the transverse ligament . The atlantodental interval is normal.$ Jefferson C1 Fracture Axial bone CT shows severe comminuted fractures involving both the posterior and anterior arches of C1 . There is also an avulsion off of the medial aspect of the left C1 lateral mass at the insertion of the transverse ligament . The atlantodental interval is normal.

$Sagittal NECT shows a type II odontoid fracture . There is slight posterior angulation and displacement of the anterior aspect of the fracture. This fracture usually occurs in older adult patients, often from a ground-level fall, and may be missed on radiographs due to osteopenia.$ Odontoid Fracture, C2 Sagittal NECT shows a type II odontoid fracture . There is slight posterior angulation and displacement of the anterior aspect of the fracture. This fracture usually occurs in older adult patients, often from a ground-level fall, and may be missed on radiographs due to osteopenia.

$Sagittal NECT shows horizontal and vertical fractures of C2 due to axial load injury. The posterior fragment can displace posteriorly and cause cord compression .$ Burst Fracture, C2 Sagittal NECT shows horizontal and vertical fractures of C2 due to axial load injury. The posterior fragment can displace posteriorly and cause cord compression .

Chiari 1 Malformation Sagittal T2WI MR shows changes of Chiari 1 malformation with pronounced inferior position of the cerebellar tonsils . There is assimilation of C1 to the occiput with abnormal position of the C1 arch . Note the associated syrinx .

Chiari 2 Malformation Sagittal T1WI MR shows the typical changes of Chiari 2 malformation with hindbrain herniation , small posterior fossa, beaked tectum , and dysmorphic clivus . Note also the associated callosal hypoplasia .

Craniovertebral Junction Variants Lateral radiograph shows the C1 fused to the occiput, resulting in dysmorphic C1-C2 articulations and dysmorphic C2 body. The odontoid is triangular in shape .

Trisomy 21 Sagittal bone CT shows C1/C2 subluxation without erosions. There was no history of trauma. Marked narrowing of the spinal canal was symptomatic.

Osteoarthritis Coronal NECT shows marked degenerative change about the right C1-C2 joint with joint space loss, bony sclerosis, and irregularity. Compare to the more normal left C1-C2 joint .

Juvenile Idiopathic Arthritis Sagittal T2WI MR shows the cortical margin of the odontoid lost anteriorly due to erosions; the soft tissue mass is due to pannus. Cranial settling is present with the odontoid at the level of clivus.

Calcium Pyrophosphate Deposition Disease Sagittal T2WI MR shows a large, predominately low signal intensity mass involving the dorsal retrodental soft tissues . There is severe cord compression from the mass with cord signal abnormality .

Tumoral Calcinosis Axial NECT at the level of C2 shows a well-defined, lobulated mass with increased attenuation surrounding the lateral C1-C2 articulation. The lesion shows the appearance of milk of calcium with diffuse increased density.

Osteomyelitis, C1-C2 Sagittal T2WI MR shows a large prevertebral abscess spanning C1 to C4 and extension posteriorly involving the interspinous region . There is involvement of the C1-C2 articulation with widening of the atlantodental interval .

Chordoma Sagittal T2WI MR shows a mass involving the craniocervical junction with marked T2 hyperintensity and spiculated internal morphology . Morphology would be consistent with either chordoma or chondrosarcoma. The location is much more typical for chordoma.

Atlantooccipital Assimilation Sagittal NECT shows findings typical for congenital assimilation of C1 to the occiput with a high-riding position of the C1 anterior arch parked underneath the inferior clivus , upward translocation of the odontoid , and lack of visible posterior C1 arch .

Paget Disease Sagittal T1WI MR in this patient with extensive Paget disease involving the calvarium shows basilar impression with upward translocation of the odontoid into the foramen magnum and draping deformity of the brainstem.

Additional Images

$Sagittal bone CT shows atrophic odontoid fracture nonunion after open reduction and internal fixation (ORIF). This usually is due not to infection but poor vascularity.$ Odontoid Fracture, C2 Sagittal bone CT shows atrophic odontoid fracture nonunion after open reduction and internal fixation (ORIF). This usually is due not to infection but poor vascularity.

$Sagittal STIR MR shows a classic example of a type 2 Hangman's fracture (Effendi classification) with bilateral pars fractures and disruption of the C2/C3 disc but intact facet joints. There is disruption of the anterior longitudinal ligament , posterior longitudinal ligament , and interspinous ligaments , indicating both column disruption.$ Hangman's Fracture, C2 Sagittal STIR MR shows a classic example of a type 2 Hangman's fracture (Effendi classification) with bilateral pars fractures and disruption of the C2/C3 disc but intact facet joints. There is disruption of the anterior longitudinal ligament , posterior longitudinal ligament , and interspinous ligaments , indicating both column disruption.

$Sagittal T1WI MR shows a nonunited fracture of dens , so-called os odontoideum. Posterior displacement of the ossicle has resulted in cord impingement.$ Os Odontoideum Sagittal T1WI MR shows a nonunited fracture of dens , so-called os odontoideum. Posterior displacement of the ossicle has resulted in cord impingement.

Craniovertebral Junction Variants Sagittal T1WI MR shows atlantooccipital assimilation and a small os odontoideum . Vertebral anomalies are also seen in the subaxial region .

$Sagittal NECT shows ballooning of the posterior process of C2 , typical of aneurysmal bone cyst. Tumor also involves vertebral body and has resulted in a pathologic fracture .$ Aneurysmal Bone Cyst Sagittal NECT shows ballooning of the posterior process of C2 , typical of aneurysmal bone cyst. Tumor also involves vertebral body and has resulted in a pathologic fracture .

Chiari 1 Malformation Sagittal T2WI MR shows the typical peg-shaped appearance of cerebellar tonsils , which descend to the level of the C1 arch. The 4th ventricle is normal. There is a small syrinx .

Chiari 2 Malformation Sagittal T2WI MR shows characteristic Chiari 2 features of a small posterior fossa and 4th ventricle, medullary kink , and verminal ectopia through the foramen magnum .

Calcium Pyrophosphate Deposition Disease Sagittal bone CT shows calcifications and soft tissue fullness at the craniocervical junction due to calcium pyrophosphate deposition disease (CPPD). CPPD of the craniocervical junction is not uncommon in older adult patients and may cause instability.

Pannus From Rheumatoid Arthritis Sagittal STIR MR shows extensive erosion of the odontoid process and a large soft tissue mass from rheumatoid arthritis (RA). RA may mimic infection or tumor.

Abscess, Epidural, Paravertebral Sagittal T2WI MR shows epidural abscess compressing the spinal cord.

Meningioma Sagittal bone CT shows a calcified mass with a dural tail arising from the ventral dura at C2, providing a clue to the dural origin. There is mass effect on adjacent spinal cord.

Multiple Myeloma Sagittal T2WI FS MR shows multiple small foci of abnormal signal intensity in the bone marrow of C-spine, clivus, and occiput. Note posterior element involvement, which is a common MR finding with myeloma.

24 KiB Raw Permalink Blame History