SPONDYLODISCITIS KEY POINTS

Transcription

1 KEY POINTS SEPPO KOSKINEN, M.D., Ph.D. Professor Divisio of Radiology Departmet of Cliical Sciece, Itervetio ad Techology (CLINTEC) Seior Cosultat Fuctio Imagig & Physiology Fuctioal Area for Trauma ad Musculoskeletal Radiology Karoliska Istitutet/Karoliska Uiversity Hospital Huddige MRI is the imagig modality of choice for imagig spial ifectio Pyogeic spodylodiscitis is typically cetered about a disc space It should be differetiated from Modic 1 edplate chages Spial epidural abscesses (ad subdural abscesses) are emergecies PYOGENIC Pyogeic spodylodiscitis is a bacterial ifectio of the boy spial colum the itervertebral discs ad/or the ligamets of the extradural spie The most commo cause is hematogeous spread of ifectio typically via the arterial route Ed-arterioral arcades i the aterior subchodral plate adjacet to the disc Veous route (UTI) PYOGENIC PYOGENIC 1 - Lumbar 2 - Thoracic 3 - Cervical spie Other etiologies iclude direct ioculatio (postop., discography, therapeutic spial ijectios) cotiguous spread from adjacet ifected sites Staphylococcus aureus 60% Eterococcus 30% y/o, me, DM, real failure, cirrhosis, immuosuppressive states, i.v. drug use Discitis i childre <4 yrs PYOGENIC begis i the aterior aspect of the vertebral bodies. It ca spread to remaider of the body adjacet disc opposite edplate Spread ito the paraspial ad/or epidural spaces is commo I childre, the still highly vascular disc is ofte the primary site of ifectio 1

2 u T1 sag u T2 sag MRI whole spie u STIR / T2 FatSat sag u T1 ax u T2 ax u C+ T1 sag u C+ T1 ax u w fatsat FOV 36 FOV 28 CT CT is more sesitive tha radiographs b/c superior aatomic resolutio May demostrate may of the same fidigs as radiographs ad MRI Itraveous cotrast is used to better evaluate the soft tissues. useful where MRI is cotraidicated, ot available, or equivocal helpful i cofirmig advaced degeerative, age-related disc chages may show disc space vacuum pheomeo,thatt may obviate the eed for biopsy Ifectio, C+ CT No ifectio. Disc space vacuum u Radiographs should be the first imagig modality obtaied u Isesitive for discitis osteomyelitis, particularly early i the course of the disease u Usually ormal durig first 8-10 days, but may remai ormal for several weeks after ifectio RADIOGRAPHS NUCLEAR MEDICINE Selected situatio limited spatial resolutio log examiatio time Sequetial 99m Tc-methylee diphosphoate ad 67 Ga-citrate sca FDG-PET 2

3 2y8m PYOGENIC imagig fidigs Disc space T2 hyperitesity, ehacemet, height loss Adjacet vertebral bodies edplate destructio T1 hypo-, T2 hyperitesity ehacemet Paraspial soft tissues ill-defied iflammatio/ swellig, abscess Epidural space reactive ehacemet/veous plexus distetio, phlegmo, abscess Adjacet vertebral bodies: edplate destructio,t1 hypo-, T2 hyperitesity, ehacemet Paraspial soft tissues: ill-defied iflammatio/ swellig, abscess Epidural space: reactive ehacemet/veous plexus distetio, phlegmo, abscess 40-year-old ma Sice November left flak pai Feb 2 MRI, suspected L2/3 spodylodiscitis CT 6 days later 3

4 40-year-old ma * Sice November left flak pai Feb 2 MRI, suspected L2/3 spodylodiscitis Feb 10, Biopsy verified Staph aur ifectio BIOPSY percutaeous image-guided (fluoroscopy or CT) eedle biopsy i patiets with vertebral osteomyelitis i routie cliical practice (high propability of ifectio) demostrated a positive culture rate of 30% i 92 cases where cliical ad imagig evaluatio were cosistet with ifectio The yield was lower (16%) whe imagig was idetermiate for ifectio. False egatives: ab-therapy, fugal if., etc. Seh JK, Gilula LA. Percutaeous eedle biopsy i diagosis ad idetificatio of causative orgaisms i cases of suspected vertebral osteomyelitis. Eur J Radiol 2012;81(5): HOWEVER I a study coducted i a earby hospital Amog the 92 patiets who uderwet biopsies, 60 (65%) were started o empirical atibiotics withi 14 days before the procedure (media 4 days; rage 1-37 days). Fortythree (72%) of these 60 patiets had positive culture results, with 38 empirical regimes matchig the pathoges later recovered. A additioal 18 positive culture samples were obtaied from 32 patiets who had o prior atibiotic exposure. The yield of biopsies was ot lower i patiets with atibiotic exposure (43 [72%] of 60 with prebiopsy atibiotics vs 18 [56%] of 32 with o atibiotics; P 5.1] atibiotic-free widow before biopsy may be more relevat to determie the impact of atibiotics but was ot assessed i this study. Marschall J, Bhava KP, Olse MA, et al. The impact of prebiopsy atibiotics o pathoge recovery i hematogeous vertebral osteomyelitis. Cliical Ifectious Diseases 2011;52:

5 EPIDURAL ABSCESS Epidural abscesses have relatively high associated morbidity ad mortality Prompt treatmet! It may also be ivolved primarily extesio of ifectio from other sites Facet joits paraspial regios retroperitoeum graulomatous ifectio Pyomyositis, with paraspial abscesses, likely due to adjacet facetitis. Also epidural abscess 33-y/o male 5

6 GRANULOMATOUS SPINAL INFECTION FUNGAL INFECTION Fugal spodylodiscitis is ucommo, (immuocompromised populatio) Cadida ad Aspergillus lack of T2 hyperitesity i the disc spaces? Multiple vertebral levels, with skip lesios or subligametous spread? Williams RL, Fukui MB, Meltzer CC, et al. Fugal spial osteomyelitis i the immuocompromised patiet: MR fidigs i three cases. AJNR Am J Neuroradiol 1999;20(3): Tuberculous Spodylodiscitis Atypical Classic Similar to pyogeic spodylodiscitis Disc space ivolvemet less severe Large paraspial abscess, smooth wall, calcificatios Subligametous spread Kwo JW, Hog SH, Choi SH, et al. MRI fidigs of Aspergillus spodylitis. AJR Am J Roetgeol 2011;197(5):W Disc sparig, with either sigle or multilevel boy ivolvemet oly Multilevel ivolvemet, cotiguous or skip lesios Vertebra plaa Posterior elemet ivolvemet Pavertebral ivolvemet F18 FDG PET/CT 6

7 MRI MONITORING THE SUCCESS OF TREATMENT Reductio of paravertebral softtissue swellig (earliest sig) Ivolved marrow: T1 ad T2 sigal icrease compared to o-ivolved marrow (fatty replacemet) Progressive reductio of cotrast ehacemet However, icreasig or persistig cotrast ehacemet with cliical improvemet ad icreasig destructio does ot ecessarily idicate treatmet failure PITFALLS, DIFF DG 23-y/o male Itradiscal foreig body iflammatio Modic I edplate chages Adersso lesio Metastasis ( good disk, bad ews ) Erosive osteoarthropathy Dialysis arthropathy Pseudoarthrosis RA Avascular ecrosis Charcot spie CRMO Lymphoma Myeloma T1 C+ FAVORS FAVORS MODIC 1 PITFALLS COMMENTS T2 hypoitesity or lack of T2 Disc space sigal T2 hyperitesity hyperitesity Disc space ehacemet Preset Abset Severely degeerated discs ca be T2 hyperitese (eve fluid sigal) Rarely abset i ifectio; may be preset i Modic 1 Disc space vacuum sig Abset, oly miimal, or disappearig Ofte preset Gas may be preset early i ifectio, i rare gasformig bacterial ifectio, or i rare fistulas with gastroitestial tract Vertebral body edplates Edplate destructio Lack of edplate destructio Modic 1 ca have edplate irregularity CT is very useful here Paraspial, epidural spaces Iflammatio ad/or abscess Abset Peripherally ehacig disc heriatio ca be cofused for abscess Locatio Ateriorly eccetric Laterally eccetric: at poit of biomechaical stress (eg, ier aspect of curve) Both spodylodiscitis ad Modic 1 are ofte alog etire edplate Fever, elevated iflammatory markers Preset Abset Fever is oly variably preset i spodylodiscitis; iflammatory markers are ospecific!! Short-term follow-up Progressio Stability If remote compariso is available, eve Modic 1 ca show sigificat progressio Dieh FE. Imagig of spie ifectio. Radiol Cli N Am 50 (2012)

8 RECOMMENDED READING? Dieh FE. Imagig of spie ifectio. Radiol Cli N Am 2012;50: Williams RL, Fukui MB, Meltzer CC, et al. Fugal spial osteomyelitis i the immuocompromised patiet: MR fidigs i three cases. Am J Neuroradiol 1999;20: Seh JK, Gilula LA. Percutaeous eedle biopsy i diagosis ad idetificatio of causative orgaisms i cases of suspected vertebral osteomyelitis. Eur J Radiol 2012;81: Kwo JW, Hog SH, Choi SH, et al. MRI fidigs of Aspergillus spodylitis. Am J Roetgeol 2011;197:W Marschall J, Bhava KP, Olse MA, et al. The impact of prebiopsy atibiotics o pathoge recovery i hematogeous vertebral osteomyelitis. Cli Ifect Dis 2011;52: Adroikou S, Bidapersad M, Goveder N, et al. Musculoskeletal tuberculosis - imagig usig low-ed ad advaced modalities for developig ad developed coutries. Acta Radiologica 2011;52: