KEY FACTS Terminology Generalized and multifactorial process affecting discovertebral unit leading to biomechanical/morphologic alterations Imaging Loss of disc space height, vacuum phenomenon seen as low signal within disc Degenerative endplate changes I → III Type I: Replacement with fibrovascular marrow Type II: Replacement by fatty marrow Type III: Bony sclerosis with little residual marrow T2 shows loss of signal from nucleus, loss of horizontal nuclear cleft…

Disc Degeneration Overview . Describing morphology alterations seen in degenerative disc disease requires common terminology to standardize communication. A series of pathoanatomic terms and definitions proposed by an interdisciplinary committee and endorsed by multiple societies is summarized here. These general terms are descriptive and independent of imaging modality. It cannot be overemphasized that the specific terms described below do not imply knowledge of etiology, symptoms, prognosis,…

KEY FACTS Terminology Hemorrhage into spinal subarachnoid space from variety of etiologies Trauma (> 50%) Aneurysmal subarachnoid hemorrhage (SAH) with spinal extension Spinal arteriovenous malformations – Mainly types II, III, IVc, conus malformations Tumor Anticoagulant therapy Infection (pneumococcal meningitis, herpes) Systemic disease Spinal artery aneurysm (rare) Imaging Fluid-fluid level within thecal sac Variable depending on stage of blood breakdown and byproducts Dynamic enhanced MRA useful as…

KEY FACTS Terminology Accumulation of blood between dura, arachnoid Imaging Intradural collection hyperintense on T1WI, predominantly hypointense on T2WI or gradient-echo imaging Thoracolumbar > lumbar or lumbosacral > cervical Clumped, loculated masses of hemorrhagic density/intensity Top Differential Diagnoses Epidural hematoma Subdural abscess Cerebrospinal fluid leakage syndrome Spinal meningitis Idiopathic hypertrophic spinal pachymeningitis Pathology Trauma Bleeding diathesis: 54% of reported cases Iatrogenic cause is factor in 2/3…

KEY FACTS Terminology Hemorrhage build-up between dura and spine not caused by significant trauma or iatrogenic procedures Imaging Extradural multisegmental T1 hyperintense fluid collection Thoracic, lumbar > cervical Lentiform or biconvex Outlined by dorsal epidural fat cranially and rostrally T1WI acute: < 48 hours Isointense > hypo-/hyperintense T1WI subacute and chronic Hyperintense > isointense T2WI heterogeneously hyperintense Top Differential Diagnoses Epidural metastasis Lymphoma Disc extrusion, migration…

KEY FACTS Terminology Spinal cord injury (SCI) Traumatic axonal injury, cord edema, &/or hemorrhage Imaging Abnormal cord signal on MR in setting of trauma Most common level of adult SCI is C4-C6 Commonly associated fracture or subluxation in younger adults (16-45 years) Underlying degenerative change (canal stenosis) predisposes to cord injury in older population SCI without radiographic abnormality is common in pediatric population (< 8 years)…

KEY FACTS Imaging Fusiform intramedullary hyperintensity tracking cerebrospinal fluid (CSF) signal Myelomalacia precedes overt syrinx formation = “presyrinx state” Cystic expansile cord lesion May appear to be “expansile” lesion, relative finding in presence of cord atrophy Consider cine (“dynamic”) PC CSF flow study if suspected obstruction to CSF flow (e.g., arachnoid adhesions) Top Differential Diagnoses Gibbs artifact Nontraumatic syrinx Myelitis Myelomalacia Pathology Current treatment assumes syrinx…

KEY FACTS Terminology Central cord syndrome (CCS), acute traumatic central cord syndrome (ATCCS) Most common partial cord syndrome Traumatic cord injury, with clinical syndrome of Bilateral weakness, arms > legs Bladder dysfunction, variable sensory loss Injury to central gray matter, corticospinal and spinothalamic tracts Imaging Radiographs may show spondylosis or congenitally diminished canal diameter MR shows hyperintense signal in central spinal cord on T2WI Significant percentage…

KEY FACTS Terminology Lateral curvature in spine due to degenerative disc and facet disease in older patients Deformity in skeletally mature patient with Cobb angle of > 10° in coronal plane Predominance of lower lumbar curves Imaging Conventional standing full-length PA and lateral radiographs for monitoring curve progression Most common from L1 to L4 Lateral listhesis, vertebral rotation Disc space loss, endplate sclerosis Circumferential endplate spurring…

KEY FACTS Terminology General term for any lateral curvature of spine Imaging Lateral curvature of spine Returns to midline at ends of curve Rotational component common Most commonly thoracic or thoracolumbar Imaging approach Radiography for initial diagnosis Multiplanar MR to screen for bone, cord abnormalities CT for surgical planning, complications Top Differential Diagnoses Idiopathic scoliosis Neuromuscular scoliosis Congenital scoliosis Scoliosis due to congenital syndromes without vertebral…

KEY FACTS Terminology Spinal curvature secondary to vertebral anomalies Hemivertebra: Unilateral or anterior vertebral hypoplasia “Butterfly” vertebra: Central vertebral cleft due to failure of central vertebral body development “Fused” vertebrae: Embryological failure of segmentation rather than fusion Klippel-Feil syndrome: Multiple cervical segmentation anomalies Imaging Accentuated dorsal thoracic spine curvature on lateral image Look for vertebral anomalies in patient with scoliosis or kyphosis May have multiple kyphotic…

KEY FACTS Terminology Autosomal-dominant dwarfism affecting spine and extremities a.k.a. achondroplastic dwarfism Imaging Shortened vertebral pedicles Decreasing interpediculate distance toward lower levels of lumbar spine Mildly flattened &/or anteriorly wedged vertebral bodies Thoracolumbar kyphosis Lumbar hyperlordosis Small foramen magnum Other Growth disturbance more obvious in proximal limbs (rhizomelic dwarfism) “Champagne glass” pelvis: Pelvic inlet is flat and broad Squared iliac wings Short ribs Enlarged skull with…

KEY FACTS Terminology Rare autosomal dominant disease from chromosomal 22 defect in which all patients develop CNS tumors Mnemonic for NF2 tumors: M ultiple i nherited s chwannomas, m eningiomas, and e pendymomas (MISME) Top Differential Diagnoses Metastases Hemangioblastomas Nonsyndromic schwannoma Nonsyndromic meningioma Nonsyndromic ependymoma Lymphoma Pathology 22q12 deletion correlates with loss of NF2 gene product “merlin” (a.k.a. schwannomin) Definite diagnosis of NF2 Bilateral CN8 (vestibular)…

KEY FACTS Terminology Synonyms: von Recklinghausen disease, peripheral neurofibromatosis Mesodermal dysplasia with neurofibromas (NFs), spinal deformity, neoplastic and nonneoplastic brain lesions, and cutaneous stigmata Imaging Kyphoscoliosis ± multiple nerve root tumors, plexiform neurofibroma, dural ectasia/lateral meningocele Tumors range from tiny to very large Top Differential Diagnoses Neurofibromatosis type 2 (NF2) (central neurofibromatosis) Chronic inflammatory demyelinating polyneuropathy Congenital hypertrophic polyradiculoneuropathies Pathology Autosomal dominant NF1 gene mutation on…

KEY FACTS Terminology Synonym: Dural ectasia Imaging Smooth remodeling of posterior vertebral body, expansion of osseous spinal canal, ± kyphoscoliosis Pedicular attenuation, widened interpediculate distance, erosion of anterior and posterior elements Patulous, expansile dural sac enlargement Easiest to appreciate on sagittal images Top Differential Diagnoses Congenital vertebral dysplasia Spinal tumor or syrinx Cauda equina syndrome of ankylosing spondylitis Pathology Etiologies include NF1, connective tissue disorders (Marfan…

KEY FACTS Terminology Synonyms: Klippel-Feil syndrome (KFS) Congenital spinal malformation characterized by segmentation failure of ≥ 2 cervical vertebrae ± thoracic, lumbar segmentation failure Imaging Single- or multiple-level congenital cervical segmentation and fusion anomalies C2-3 (50%) > C5-6 (33%) > craniovertebral junction, upper thoracic spine Vertebral bodies usually smaller than normal Vertebral body narrowing (“wasp waist”) at fused rudimentary disc space ± fusion of posterior elements…

KEY FACTS Terminology Synonyms: Tethered cord syndrome (TCS), tight filum terminale syndrome Imaging Stretched, thinned cord with low-lying conus, thickened filum ± fibrolipoma/terminal lipoma, dysraphism, vertebral segmentation anomalies ↓ spinal cord motion Top Differential Diagnoses Normal variant low-lying conus Open or closed spinal dysraphism Postsurgical low-lying conus Pathology Tethering stretches nerve fibers, arterioles, and venules → impaired oxidative metabolism of conus and nerve roots → syringohydromyelia,…

KEY FACTS Terminology Synonym: Sacral dimple Imaging Low sacral dimple connecting to coccyx by fibrous tract Usually resides within intergluteal cleft No intradural extension by definition Variable size; deeper dimples usually evoke more physician and parental concern Top Differential Diagnoses Dorsal dermal sinus Pilonidal sinus Pathology Congenital Tract usually atretic; may occasionally be patent with fluid in lumen Clinical Issues Often asymptomatic discovery by parents during…

KEY FACTS Terminology Synonyms: Dermal sinus tract (DST) Midline/paramedian stratified squamous epithelial-lined sinus tract Extends inward from skin surface for variable distance Imaging Sinus tract easily identified superimposed on background of cutaneous fat Terminus usually conus medullaris (lumbosacral) or central spinal canal (cervical, thoracic) Top Differential Diagnoses Low coccygeal midline dimple Pilonidal sinus (Epi)dermoid tumor without dermal sinus Pathology Focal incorporation of cutaneous ectoderm into neural…

KEY FACTS Terminology Posterior spinal defect lacking skin covering → neural tissue, cerebrospinal fluid (CSF), and meninges exposed to air Synonyms: Meningomyelocele, open spinal dysraphism, spina bifida aperta, spina bifida cystica Imaging Lumbosacral (44%) > thoracolumbar (32%) > lumbar (22%) > thoracic (2%) Preoperative: Posterior spinal defect lacking skin covering → neural tissue, CSF, and meninges exposed to air Postoperative: Dysraphism, low-lying cord/roots, postoperative skin closure…