1.
Imaging Bone-Cartilage Interactions in Osteoarthritis Using [18F]-NaF PET-MRI.
Savic, D, Pedoia, V, Seo, Y, Yang, J, Bucknor, M, Franc, BL, Majumdar, S
Molecular imaging. 2016;:1-12
Abstract
PURPOSE Simultaneous positron emission tomography-magnetic resonance imaging (PET-MRI) is an emerging technology providing both anatomical and functional images without increasing the scan time. Compared to the traditional PET/computed tomography imaging, it also exposes the patient to significantly less radiation and provides better anatomical images as MRI provides superior soft tissue characterization. Using PET-MRI, we aim to study interactions between cartilage composition and bone function simultaneously, in knee osteoarthritis (OA). PROCEDURES In this article, bone turnover and remodeling was studied using [18F]-sodium fluoride (NaF) PET data. Quantitative MR-derived T1ρ relaxation times characterized the biochemical cartilage degeneration. Sixteen participants with early signs of OA of the knee received intravenous injections of [18F]-NaF at the onset of PET-MR image acquisition. Regions of interest were identified, and kinetic analysis of dynamic PET data provided the rate of uptake ( Ki) and the normalized uptake (standardized uptake value) of [18F]-NaF in the bone. Morphological MR images and quantitative voxel-based T1ρ maps of cartilage were obtained using an atlas-based registration technique to segment cartilage automatically. Voxel-by-voxel statistical parameter mapping was used to investigate the relationship between bone and cartilage. RESULTS Increases in cartilage T1ρ, indicating degenerative changes, were associated with increased turnover in the adjoining bone but reduced turnover in the nonadjoining compartments. Associations between pain and increased bone uptake were seen in the absence of morphological lesions in cartilage, but the relationship was reversed in the presence of incident cartilage lesions. CONCLUSION This study shows significant cartilage and bone interactions in OA of the knee joint using simultaneous [18F]-NaF PET-MR, the first in human study. These observations highlight the complex biomechanical and biochemical interactions in the whole knee joint in OA, which potentially could help assess therapeutic targets in treating OA.
2.
PET Index of Bone Glucose Metabolism (PIBGM) Classification of PET/CT Data for Fever of Unknown Origin Diagnosis.
Yang, J, Liu, X, Ai, D, Fan, J, Zheng, Y, Li, F, Huo, L, Wang, Y
PloS one. 2015;(6):e0130173
Abstract
OBJECTIVES Fever of unknown origin (FUO) remains a challenge in clinical practice. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is helpful in diagnosing the etiology of FUO. This paper aims to develop a completely automatic classification method based on PET/CT data for the computer-assisted diagnosis of FUO. METHODS We retrospectively analyzed the FDG PET/CT scan of 175 FUO patients, 79 males and 96 females. The final diagnosis of all FUO patients was achieved through pathology or clinical evaluation, including 108 normal patients and 67 FUO patients. CT anatomic information was used to acquire bone functional information from PET images. The skeletal system of FUO patients was classified by analyzing the standardized uptake value (SUV) and the PET index of bone glucose metabolism (PIBGM). The SUV distributions in the bone marrow and the bone cortex were also studied in detail. RESULTS The SUV and PIBGM of the bone marrow only slightly differed between the FUO patients and normal people, whereas the SUV of whole bone structures and the PIBGM of the bone cortex significantly differed between the normal people and FUO patients. The method detected 43 patients from 67 FUO patients, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 64.18%, 95%, 93.48%, 72.73%, and 83.33%, respectively. CONCLUSION The experimental results demonstrate that the study can achieve automatic classification of FUO patients by the proposed novel biomarker of PIBGM, which has the potential to be utilized in clinical practice.
3.
Diagnostic performance of 18F-FDG-PET versus scintigraphy in patients with inflammatory bowel disease: a meta-analysis of prospective literature.
Zhang, J, Li, LF, Zhu, YJ, Qiu, H, Xu, Q, Yang, J, Weng, WW, Liu, NH
Nuclear medicine communications. 2014;(12):1233-46
Abstract
OBJECTIVE The aim of this study was to evaluate the diagnostic performance of fluorine-18 fluorodeoxyglucose-PET (F-FDG-PET), leukocyte scintigraphy (LS), and monoclonal antigranulocyte antibody scintigraphy (MAAS) in patients with inflammatory bowel disease (IBD) and perform pairwise comparisons of the diagnostic accuracy between these different imaging modalities. METHODS Through a search of PubMed, EMBASE, and the Cochrane Library (January 1993-May 2013), we performed a random effects meta-analysis and constructed summary receiver operating characteristic curves on per-bowel-segment or per-patient basis. Two-sample Z-tests were performed to evaluate differences in sensitivity, specificity, area under the curve (AUC), and the Q* index between any two diagnostic modalities on per-bowel-segment basis. RESULTS Twenty prospective studies were reviewed. On per-bowel-segment basis, the F-FDG-PET had a pooled sensitivity of 0.84, specificity of 0.86, AUC of 0.913, and Q* index of 0.845, whereas for LS, the corresponding values were 0.79, 0.86, 0.877, and 0.808, respectively, and for MAAS they were 0.45, 0.94, 0.524, and 0.518, respectively. On per-patient basis, the corresponding values of LS were 0.91, 0.85, 0.937, and 0.874, respectively. Statistically significant differences were not found in the sensitivity, specificity, AUC, and Q* index between F-FDG-PET and LS on per-bowel-segment basis. CONCLUSION F-FDG-PET has a high degree of diagnostic performance compared with LS and MAAS on per-bowel-segment basis in patients with IBD. LS may be used with satisfactory diagnostic accuracy in detecting active IBD when PET systems are unavailable. A larger prospective validation of these findings would be valuable.