Comparison of the Diagnostic Value of MRI and Whole Body 18F-FDG PET/CT in Diagnosis of Spondylodiscitis

Abstract

Spondylodiscitis is a spine infection for which a diagnosis by a magnetic resonance imaging (MRI) is considered the most appropriate imaging technique. The aim of this study was to compare the role of an 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and an MRI in this field. For 56 patients with suspected spondylodiscitis for whom MRI and 18F-FDG PET/CT were performed, we retrospectively analyzed the results. Cohen’s κ was applied to evaluate the agreement between the two techniques in all patients and in subgroups with a different number of spinal districts analyzed by the MRI. Sensitivity, specificity, and accuracy were also evaluated. The agreements of the 18F-FDG PET/CT and MRI in the evaluation of the entire population, whole-spine MRI, and two-districts MRI were moderate (κ = 0.456, κ = 0.432, and κ = 0.429, respectively). In patients for whom one-district MRI was performed, 18F-FDG PET/CT and MRI were both positive and completely concordant (κ = 1). We also separately evaluated patients with suspected spondylodiscitis caused by Mycobacterium tuberculosis for whom the MRI and 18F-FDG PET/CT were always concordant excepting in 2 of the 18 (11%) patients. Sensitivity, specificity, and accuracy of the MRI and 18F-FDG PET/CT were 100%, 60%, 97%, and 92%, 100%, and 94%, respectively. Our results confirmed the 18F-FDG PET/CT diagnostic value in the diagnosis of spondylodiscitis is comparable to that of MRI for the entire spine evaluation. This could be considered a complementary technique or a valid alternative to MRI.

Detection of Spinal Tuberculosis by F-18 FDG PET/CT as a Cause of Unusual Referred Pain in the Right Upper Quadrant of Abdomen

“…10 11 12 13 It could be considered as a complementary or alternative tool to the imaging gold standard MRI for spondylodiscitis. 14 In our case, the intervertebral disc was spared, which is a characteristic feature to differentiate TB from bacterial cause in early vertebral osteomyelitis. Patients with thoracic spine disease are at risk of paraparesis or paraplegia and the disease has to be identified at the earliest.…”

State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

“…Quantitative analysis : SUV max is the most validated semi-quantitative parameter. No cut-off has been established to differentiate between positive and negative findings; SUV max > 3 seems to be compatible with SI [ 11 ]. Semi-quantitative analysis is also useful to evaluate the response to therapy; in particular, a follow-up SUV max reduction compared to basal value is considered suggestive of a good response to treatment.…”

Spine Infections: The Role of Fluorodeoxyglucose Positron Emission Tomography (FDG PET) in the Context of the Actual Diagnosis Guideline

“…Lately, few authors [ 42 , 63 - 66 ], both with retrospective and prospective studies, have examined the diagnostic value of 18 F-fluorodeoxyglucose (FDG-PET/CT and MRI in diagnosing SD and its complications ( i.e., epidural and paraspinal abscesses). They concluded that the two techniques are both necessary in diagnosing vertebral osteomyelitis SD and could be considered complementary or a valid alternative to MRI [ 64 ]. FDG-PET/CT is a robust diagnostic tool to diagnose postoperative hardware related spinal infections [ 65 ], and the advantages of an FDG- PET/CT are the larger field of view (FOV), allowing diagnosis of regional abscesses that can be missed on MRI [ 42 , 67 ] and the visualization of metastatic infection especially in patients with bacteriemia, and the possibility to avoid metal implant artifacts [ 42 ].…”