A comparison of the diagnostic value of MRI and18F-FDG-PET/CT in suspected spondylodiscitis.
OBJECTIVE
The purpose of this study was to evaluate the diagnostic value of18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT scan) and magnetic resonance imaging (MRI) in diagnosing spondylodiscitis and its complications, such as epidural and paraspinal abscesses.


METHODS
From January 2006 to August 2013 patients with a clinical suspicion of spondylodiscitis, with an infection, or with fever of unknown origin were retrospectively included if18F-FDG-PET/CT and MRI of the spine were performed within a 2-week time span. Imaging results were compared to the final clinical diagnosis and follow-up data were collected.


RESULTS
Sixty-eight patients were included of whom 49 patients were diagnosed with spondylodiscitis. MRI showed an overall sensitivity of 67 % and specificity of 84 %. Diagnostic accuracy was 58 %, when MRI was performed within 2 weeks after the start of symptoms and improved to 82 %, when performed more than 2 weeks after onset of symptoms.18F-FDG-PET/CT showed a sensitivity of 96 % and a specificity of 95 %, with no relation to the interval between the scan and the start of symptoms.


CONCLUSIONS
As compared to MRI,18F-FDG-PET/CT has superior diagnostic value for detecting early spondylodiscitis. After 2 weeks both techniques perform similarly.
Department of Internal Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Carolijn
C
Smids
Department of Internal Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands. ilsekouijzer@gmail.com.
Ilse J E
IJ
Kouijzer
Department of Internal Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.|Sint Maartenskliniek, P.O. Box 9011, 6500 GM, Nijmegen, The Netherlands.
Fidel J
FJ
Vos
Department of Internal Medicine, Canisius-Wilhelmina Hospital, P.O. Box 9015, 6500 GS, Nijmegen, The Netherlands.
Tom
T
Sprong
Department of Orthopaedics, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Allard J F
AJ
Hosman
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Jacky W J
JW
de Rooy
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Erik H J G
EH
Aarntzen
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.|Department of Nuclear Medicine, Leiden University Medical Center, P.O. Box 9600, 2300 RC, Leiden, The Netherlands.|MIRA Institute for Biomedical Technology and Technical Medicine, Biomedical Photonic Imaging Group, University of Twente, P.O Box 217, 7500 AE, Enschede, The Netherlands.
Lioe-Fee
LF
de Geus-Oei
Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Wim J G
WJ
Oyen
Department of Internal Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Chantal P
CP
Bleeker-Rovers
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D015299:Discitis / Q000000981:diagnostic imaging* / Q000473:pathology; D020802:Epidural Abscess; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000627:therapeutic use*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology; D055815:Young Adult
D019788:Fluorodeoxyglucose F18
18F-FDG-PET/CT; Abscess; MRI; Spondylodiscitis