KEY FACTS Terminology Extension of primary tumor to spine where bone production exceeds bone destruction Imaging Multiple osteoblastic lesions in spine May coexist with areas of osteolytic tumor, soft tissue mass Lesion distribution proportional to red marrow (lumbar > thoracic > cervical) MR signal typically diminished on T1, T2WI in areas of osteoblastic metastases Sclerotic metastases usually tracer avid on bone scan Top Differential Diagnoses Treated…

Anatomy-Based Imaging Issues Neoplasms affecting the spine may spread by direct extension via the lymphatic system, the hematogenous route, or along the cerebrospinal fluid (CSF) pathways. There can also be combinations of these pathways involved, with the most typical being hematogenous metastatic dissemination to vertebral bodies with subsequent direct extension into the epidural space. Primary tumors located in soft tissues may extend into the vertebral column…

KEY FACTS Terminology Paraneoplastic neurologic disorder Antineuronal immune mechanism targeting CNS, occurring in conjunction with cancer Imaging Longitudinally extensive, symmetric, tract-specific signal changes within spinal cord that often enhance after gadolinium administration in patient with cancer Signal abnormality in ~ 70% of cases Lateral, dorsal columns Central gray matter Top Differential Diagnoses Cord infarction Neuromyelitis optica B12 deficiency (subacute combined degeneration) Metastatic disease Neurosarcoidosis Pathology Paraneoplastic…

KEY FACTS Terminology Vitamin B12 deficiency produces selective degeneration of dorsal ± lateral spinal cord columns Imaging Longitudinal dorsal cord T2 signal abnormality Axial image → “inverted V” or “inverted rabbit ears” within dorsal spinal cord ± mild dorsal column enhancement Top Differential Diagnoses Infectious myelitis HIV vacuolar myelopathy Varicella-Zoster/herpes Inflammatory demyelination Multiple sclerosis Acute disseminated encephalomyelitis Acute transverse myelitis Acute presentation → diffuse multisegmental cord…

KEY FACTS Terminology Neurosarcoidosis Noncaseating granulomatous disease of spine and spinal cord Imaging Combination of leptomeningeal and peripheral intramedullary mass-like enhancement suggestive of spinal sarcoidosis Intramedullary Fusiform cord enlargement Enhancing intramedullary masses Focal or diffuse T2-hyperintense lesions Intradural extramedullary Leptomeningeal enhancement Dural masses Extradural CT/radiographs: Sclerotic or mixed lytic and sclerotic lesions Intracranial (look at brain on sagittal cervical spine scans!) Frequently affects meninges, especially near…

KEY FACTS Terminology Clinically heterogeneous, grossly symmetric, sensory and motor neuropathy evolving as monophasic, relapsing, or progressive disorder Develops over > 8 weeks Imaging Enlargement and abnormal T2 hyperintensity of nerve roots, plexi, or peripheral nerves Spinal nerve roots and peripheral nerves (extraforaminal > intradural) Lumbar > cervical, brachial plexus, thoracic/intercostal > cranial nerve Top Differential Diagnoses Guillain-Barré (acute inflammatory demyelinating polyneuropathy) Inherited demyelinating neuropathy Neurofibromatosis…

KEY FACTS Terminology Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) a.k.a. Guillain-Barré syndrome (GBS) Autoimmune postinfectious or postvaccinial acute inflammatory demyelination of peripheral nerves, nerve roots, cranial nerves Imaging Smooth pial enhancement of cauda equina and conus medullaris Nerve roots often slightly enlarged Conus not enlarged Axial T1WI C+ MR shows preferential contrast accentuation of ventral roots in cauda Top Differential Diagnoses Miller-Fischer syndrome Chronic polyneuropathies Subacute inflammatory…

KEY FACTS Terminology Para-/postinfectious immune-mediated inflammatory disorder of white matter (WM) Antibodies to pathogens exhibit cross-immunoreactivity with myelin basic protein Imaging Multifocal short-segment WM lesions with relatively little mass effect or vasogenic edema Flame-shaped lesions with slight cord swelling Dorsal white matter more voluminous May see gray matter involvement Variable enhancement, depending on stage of disease May see nerve enhancement Brain almost always involved Top Differential…

KEY FACTS Terminology Neuromyelitis optica (NMO) NMO spectrum disorders Idiopathic inflammatory demyelinating disorder of CNS characterized by severe attacks of optic neuritis and myelitis Imaging Hyperintense, mildly enlarged optic nerves Expansile, hyperintense cord signal, ≥ 3 segments Long segment optic nerve enhancement Acute cord lesions show patchy enhancement Patchy enhancement with blurred margins (“cloud-like” enhancement) in cerebral lesions “Pencil-thin” ependymal enhancement Top Differential Diagnoses Multiple sclerosis…

KEY FACTS Terminology Primary demyelinating disease of central nervous system with multiple lesions disseminated over time and space Concomitant intracranial lesions in periventricular, subcallosal, brain stem, or cerebellar white matter Imaging Isolated spinal cord disease (10-20%) Cervical segment is most commonly affected Dorsolateral aspect of cord < 1/2 of cross-sectional area of spinal cord < 2 vertebral segments in length Sagittal and axial T1WI & T2WI…

KEY FACTS Terminology Inflammatory disorder involving both halves of spinal cord, resulting in bilateral motor, sensory, and autonomic dysfunction Imaging Central cord expansile lesion > 2 vertebral segments in length ± variable eccentric enhancement Top Differential Diagnoses Multiple sclerosis Neuromyelitis optica Spinal cord neoplasm Spinal cord infarction Pathology Autoimmune phenomenon with formation of antigen-antibody complexes Small vessel vasculopathy → cord ischemia Associated demyelinating process Clinical Issues…

KEY FACTS Terminology Noncompressive myelopathy Acute transverse myelopathy (ATM) is broad generic term encompassing heterogeneous group of disorders causing cord dysfunction Etiologies include inflammatory causes (ATM) + vascular disease + radiation + paraneoplastic + idiopathic (unknown) ATM is more specific term for cord dysfunction that is inflammatory in etiology – Inflammation defined by cerebrospinal fluid findings and MR enhancement Imaging Hyperintense lesion on T2WI with mild…

KEY FACTS Terminology Infection in setting of immunocompromised state HIV(+) Chronic/systemic illness Steroid therapy Cancer ± chemotherapy Imaging CT → define osseous involvement MR → evaluate extent of intramedullary, intradural extramedullary, and extradural involvement Discitis/osteomyelitis → loss of disc height, bony endplate erosive changes Enhancement of irregular adjacent endplates, blurring of dark cortical margin of endplates Epidural abscess/phlegmon → soft tissue in ventral/dorsal extradural space Homogeneous…

KEY FACTS Terminology Myelopathy resulting from primary HIV infection Most common cause of spinal cord disease in AIDS patients; prevalence of 20-55% Imaging Most common: Atrophy Spinal cord T2 hyperintensity ± patchy enhancement Thoracic > cervical; ↑ rostral as disease progresses Top Differential Diagnoses B12 deficiency Infection (varicella-zoster virus, human T-cell leukemia/lymphoma virus) Multiple sclerosis Transverse myelitis Delayed radiation myelopathy Pathology DNA lentivirus/retrovirus attacks spine monocytes,…

KEY FACTS Terminology Acute inflammatory insult of spinal cord due to direct viral infection or postviral immunologic attack Imaging Swollen, edematous spinal cord with segmental contiguous involvement From 1 segment to extensive cord involvement Fusiform expansion of spinal cord Diffuse increase in T2 signal intensity through involved segment Variable, patchy enhancement of involved cord segment Top Differential Diagnoses “Idiopathic” transverse myelitis Multiple sclerosis Most lesions are…

KEY FACTS Terminology Spinal subdural abscess (SSA) Intradural extramedullary ring-enhancing fluid collection of pus in “potential” space between dura and arachnoid Imaging Thoracolumbar region most common Presence suggested by mass effect on cord and obliterated subarachnoid space Cord displacement: ± impingement and edema Increased subdural density on NECT MR T2 hyperintense/T1 hypointense Heterogeneous, diffuse subdural enhancement Rim-enhancing fluid collection Best imaging modality MR with contrast →…

KEY FACTS Terminology Spinal epidural abscess Extradural spinal infection with abscess formation Imaging Lower thoracic and lumbar > upper thoracic and cervical CT Enhancing epidural mass narrowing central canal MR T1WI: Iso- to hypointense to cord T2WI/STIR: Hyperintense T1WI C+: Homogeneously or heterogeneously enhancing phlegmon Peripherally enhancing necrotic abscess Fat saturation: STIR, T2WI FS, T1WI C+ FS Increases lesion conspicuity by suppressing signal from epidural fat…

KEY FACTS Terminology Paraspinal phlegmon surrounding peripherally enhancing fluid collections Imaging Pre vertebral/ para vertebral space Multiple or multiloculated collections along muscle plane NECT Amorphous low-density intramuscular collection Calcified psoas abscesses characteristic of tuberculous paraspinal abscess Endplate destruction MR Iso- to hypointense on T1WI Hyperintense fluid collection and surrounding muscle on T2WI and STIR Diffuse enhancement: Phlegmon Peripherally enhancing fluid collection(s): Abscess Top Differential Diagnoses Neoplasm,…

KEY FACTS Terminology Tuberculosis (TB); TB spondylitis (TS) Extrapulmonary granulomatous infection of spine/adjacent tissues Also known as Pott (Pott's) disease Imaging Gibbus vertebrae with relatively intact intervertebral discs, large paraspinal abscesses Midthoracic or thoracolumbar > lumbar, cervical Isolated posterior element involvement possible MR best modality to evaluate extent of disease, assess response to treatment Sagittal STIR or FSE T2 with fat saturation most sensitive for bone…

KEY FACTS Imaging MR Diffuse, extensive subarachnoid enhancement Smooth or irregular meningeal enhancement Top Differential Diagnoses Carcinomatous meningitis Focal or diffuse, sheet-like or nodular enhancement along cord or nerve roots Sarcoidosis Leptomeningeal + nerve root enhancement mimics spinal meningitis Lumbar arachnoiditis Empty-sac sign (nerve roots stuck to inside of thecal sac) Guillain-Barré syndrome Inflammatory demyelination typically following recent viral illness Intracranial hypotension (spontaneous or iatrogenic) Engorged…