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Objective: To evaluate a computer-aided approach to the assessment of spinal inflammation on magnetic resonance imaging (MRI) in spondyloarthritis as compared to visual assessment., Methods: Following institutional ethics approval, 32 patients (mean ± SD age 35.3 ± 10.2 years) with active ankylosing spondylitis underwent treatment with methotrexate and infliximab for 30 weeks. Spinal MRI examination (T1-weighted, T2-weighted fat-suppressed, and postcontrast T1-weighted fat-suppressed sagittal sequences using a 1.5T MRI system) was performed at baseline and at 30 weeks. Following manual identification of the vertebral corners, vertebral body segmentation was performed using a deformable model that automatically isolated the 4 vertebral corner areas, allowing automatic measurement of the relative mean corner intensity of each vertebral corner before and after treatment. Quantitative computer-aided assessment of spinal inflammation was compared with a semiquantitative visual assessment of spinal inflammation (the Berlin method)., Results: Computer-aided quantification was quick and highly reliable, and it identified increases in vertebral corner edema or enhancement that were significantly decreased following treatment (P < 0.5). For computer-aided analysis, there was excellent inter- and intrarater correlation of both corner edema and enhancement (intraclass correlation coefficients [ICCs] >0.99), and the correlations were better than those for visual analysis (ICCs 0.83-0.96). For computer-aided analysis, the standardized response mean was 1.67 for corner edema and 1.64 for enhancement, as compared to 1.20 and 1.18, respectively, for visual analysis. Computer-aided quantification of MRI data correlated better (r = 0.50-0.53, P < 0.01) with clinical features of spinal disease activity pre- and posttreatment than did visual analysis of spinal inflammation (r = 0.37-0.43, P > 0.02)., Conclusion: Computer-aided assessment of spinal inflammation in spondyloarthritis is quick, reliable, and sensitive and correlates better with clinical disease activity than does visual assessment by the Berlin method., (© 2015, American College of Rheumatology.)

The aim of this study was to explore the feasibility and repeatability of amide proton transfer-weighted (APTw) MRI for the head and neck on clinical MRI scanners. Six healthy volunteers and four patients with head and neck tumors underwent APTw MRI scanning at 3 T. The APTw signal was quantified by the asymmetric magnetization transfer ratio (MTRasym) at 3.5 ppm. Z spectra of normal tissues in the head and neck (masseter muscle, parotid glands, submandibular glands and thyroid glands) were analyzed in healthy volunteers. Inter-scan repeatability of APTw MRI was evaluated in six healthy volunteers. Z spectra of patients with head and neck tumors were produced and APTw signals in these tumors were analyzed. APTw MRI scanning was successful for all 10 subjects. The parotid glands showed the highest APTw signal (~7.6% average), whereas the APTw signals in other tissues were relatively moderate. The repeatability of APTw signals from the masseter muscle, parotid gland, submandibular gland and thyroid gland of healthy volunteers was established. Four head and neck tumors showed positive mean APTw ranging from 1.2% to 3.2%, distinguishable from surrounding normal tissues. APTw MRI was feasible for use in the head and neck regions at 3 T. The preliminary results on patients with head and neck tumors indicated the potential of APTw MRI for clinical applications., (Copyright © 2014 John Wiley & Sons, Ltd.)

Objective: To evaluate the relationship of functional magnetic resonance imaging (MRI) parameters, including choline/creatine ratio (Cho/Cr) and apparent diffusion coefficient (ADC) with protein expression of 10 common tumor and prognostic markers in head and neck squamous cell carcinoma., Study Design: Cross-sectional study., Setting: University hospital., Subjects and Methods: The Cho/Cr and ADC obtained from 74 patients with head and neck squamous cell carcinoma were correlated with the expression level of the 10 protein markers as determined by immunohistochemistry., Results: Cho/Cr showed significant positive correlations with cyclooxygenase 2 in primary tumors (r = 0.714), and epidermal growth factor receptor in metastatic cervical lymph nodes (r = 0.522). ADC showed significant (r = -0.591) negative correlation with human epidermal growth factor receptor 2 in metastatic cervical lymph nodes., Conclusion: There are relationships between protein and functional MRI markers. Future research in this direction may improve our understanding of the cancer micro-environment., (Copyright © 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.)

Most traditional methods for T(1) map estimation in MRI with fast low-angle-shot sequences are aimed at high efficiency by compromising the fitting accuracy. In this paper, the fundamental problem of parameter estimation in fast low-angle-shot MRI was re-examined, and an accurate and fast optimization approach, named concatenated optimization for parameter estimation, was proposed for the regression of data points acquired with multiple flip angles. The initial estimation of T(1) was obtained from the linear regression, followed by the constrained nonlinear regression based on the initial estimates. This heterogeneous initialization strategy improves the fitting accuracy and reduces the computational time. A computationally efficient implementation of concatenated optimization for parameter estimation was achieved based on the graphic processing unit, named as concatenated optimization for parameter estimation graphic processing unit. In experimental comparison with Fram's method and the Fitter Tool in Jim, the proposed methods are capable of achieving significantly higher efficiency and more accurate estimations., ((c) 2010 Wiley-Liss, Inc.)

Ischemia is the defined pathway leading to steroid-associated osteonecrosis (ON). Early detection of ischemic condition may help predict later ON occurrence. Bone marrow perfusion function evaluation by perfusion magnetic resonance imaging (MRI) may be a unique modality for this application. Twenty-five adult male New Zealand white rabbits were used in this study. Lipopolysaccharide (LPS) and methylprednisolone (MPS) were administrated for ON induction based on a published protocol. T1-weighted and fat suppression T2-weighted MR imaging (conventional MRI) were performed for ON lesion detection based on the abnormal signal in the proximal femora at week 0 as the baseline (before LPS injection), and week 1 and week 2 after MPS injection. At the same time, the blood perfusion function in the proximal femora was measured by perfusion MRI. Maximum enhancement (ME)--an index of MRI perfusion function was analyzed. After MRI scanning, the proximal femora were prepared histopathologically for ON lesion analysis. The rabbit with bilateral histopathological ON lesions was defined as an ON+ rabbit and included in the ON+ group evaluated at week 1 and week 2, respectively, and the rabbit without ON lesions in bilateral femora was classified into the ON- group. For the underlying mechanism of perfusion change, the extravascular marrow fat cells were measured and the intravascular endothelium inflammation injury indicator of tissue factor (TF) expression and thrombus formation were detected. In ON+ group, ME in perfusion MRI showed a significant decrease at week 1 and week 2 as compared with the baseline (p < 0.01). There was a more than 50% decrease in ME at week 1 in ON+ group; whereas there were no detectable ON lesions by conventional MRI at week 1, though 93% (14/15) rabbits could be detected at week 2 in ON+ group. In ON- group, ME showed a slight decrease at week 1 (less than 30%), and nearly recovered to normal at week 2 as compared with the baseline. Histological results showed a much larger average marrow fat area and more severe marrow blood sinusoids compression from surrounding crowded fat cells, and stronger positive TF expression in marrow endothelium and more thrombus formation in ON+ rabbits than ON- rabbits. This study demonstrated that functional perfusion MRI could predict development of steroid-associated ON. Our experimental data suggested that perfusion MRI might be a sensitive noninvasive modality for monitoring steroid-associated ON in patients., (Copyright 2008 Orthopaedic Research Society)

Proton MRS and MRI were used to monitor the progression of severe cerebral radiation injuries in 10 patients over a period of 18 months. An unknown resonance (Px) in the 2.37-2.40 ppm region was consistently detected in the affected temporal lobes of four patients. The detection of Px was only confined to spectra with lactate (Lac) and in patients with the highest severity grading of radiation injury. The incidence of Px in Lac-positive spectra was 42.8% (15/35) and in lesions with highest injury grading was 46.8% (15/32). Lesions with Px had significantly higher Lac/creatine (Cr) ratios and more extensive mass effect changes when compared to lesions without Px. The probable identity of Px was examined in the context of anaerobic glycolysis producing pyruvate (2.37 ppm) and the model of metabolic changes in brain abscess formation implicating succinate (2.40 ppm)., (Copyright 2001 Wiley-Liss, Inc.)