Diagnosis of Spinal Infections eEdE-221 (Shared Display) A. Boikov, L. Loevner, K. Learned University of Pennsylvania Health System, Philadelphia, PA

Disclosures None

Learning objectives This educational exhibit will offer a pattern- based approach to the diagnosis of spinal infection. Examples of common and uncommon spinal infections will be presented to make the complex task of diagnosing spinal infection more straightforward. Examples of atypical infections that mimic neoplasm will be presented

Case 1: back pain & fever

T2 T1 FLAIR T1 Post contrast

Relevant imaging findings: –XR Endplate destruction Loss of disc height Case 1: back pain & fever

Relevant imaging findings: –MRI: Disk and vertebral body: T1-hypointensity/T2- hyperintensity (edema) + enhancement Endplate T2 hyperintensity is least specific Endplate erosion and enhancement more specific Contiguous vertebral levels Paraspinous inflammatory changes Case 1: back pain & fever

Diagnosis? S aureus spondylodiscitis –Pathophysiology: Typically hematogenous seeding of endplate with secondary discitis S aureus most common –Clinical: acute or chronic pain Pneumonia or UTI Post-operative WBC and ESR elevated Case 1: back pain & fever

R. Rahme, and R. Moussa AJNR Am J Neuroradiol 2008;29: Case 2: worsening back pain

T1-hypointense vertebral bodies and disc T2-hyperintense vertebral bodies and disc T1 T2

Case 2b: worsening back pain Six months

Diagnosis? –Modic type 1 changes & accelerated degenerative disc disease Why not spondylodiscitis? –Both can have similar MRI characteristics –Absence of paraspinous inflammation –Clinical context No signs/symptoms of infection Cases 2 & 2b: worsening back pain

Case 3: Back pain, fever, HIV+ T1T2 FS Post-contrast FS T1

Spondylodiscitis with epidural abscess –An important complication –Immunocompromised patients –IV drug users Case 3: Back pain, fever, HIV+ T1-hypointense, T2-hyperintense enhancing intramedullary fluid collection

Epidural abscess: pathophysiology –Either direct extension or hematogenous S aureus typically (45%), gram negative rods, anaerobes, fungi Case 3: Back pain, fever, HIV+

Case 4: Back pain, end-stage renal disease Theodorou DJ, et al. Imaging in dialysis spondyloarthropathy. Seminar Dial. 2002;15(4): T2

MRI –T2-hyperintense disc and T2-hypointense vertebral bodies Dx: dialysis spondyloarthropathy –MRI findings are atypical for spondylodiscitis Case 4: Back pain, end-stage renal disease

Dialysis spondyloarthropathy Imaging: –Usually cervical –Destruction of disc and adjacent vertebral bodies –Usually LOW T2 (as opposed to infection) Clinical: dialysis pts –No clinical evidence of infection –Pathophysiology: possibly amyloid-related Case 4: Back pain, end-stage renal disease

T2 FST1 Case 5: back pain, HIV+

T2FST1 Case 5: back pain, HIV+

MRI findings: –Large paraspinous abscess –Relatively preserved endplates –Relatively little disc involvement –Psoas abscess Case 5: back pain, HIV+

Diagnosis: granulomatous osteomyelitis (brucellosis) Vs classical bacterial spondylodiscitis: –Soft tissue component > bone/disc involvement –Less clinical signs of infection –Immunocompromised Vs malignancy –Involves contiguous vertebral levels Case 5: back pain, HIV+

Case 5b: back pain in immigrant with cavitary lung lesions and hilar lymphadenopathy

Diagnosis: tuberculous spondylitis (Pott’s disease) –Involvement of the posterior elements –Ongoing active TB in another organ –Often involves >3 vertebral levels –Paraspinal mass –Subligamentous spread of disease

Tuberculous spondylitis T2 T1 Gibbus deformity: Focal kyphosis Pathologic compression fracture secondary to TB spondylitis Circumferential phlegmon

References C.J. Kim, et al. A comparative study of pyogenic and tuberculous spondylodiscitis. Spine (Phila Pa 1976) 2010;35:E1096 D.J. Theodorou, S.J. Theodorou and D. Resnick. Imaging in dialysis spondyloarthropathy. Seminar Dial 2002; 15: R. Rahme, and R. Moussa. The Modic vertebral endplate and marrow changes: pathologic significance and relation to low back pain and segmental instability of the lumbar spine. AJNR Am J Neuroradiol 2008;29: D.M. Yousem, R.D. Zimmerman and R.I. Grossman. Neuroradiology: the requisites (3 rd Ed.). Mosby Elsevier: Philadelphia