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Objective: To determine whether MR perfusion indices or marrow fat content at baseline can predict areal bone mineral density (BMDa) loss.Methods: Repeat dual x-ray absorptiometry (DXA) of the hip was performed in female subjects at 2 years (n = 52) and 4 years (n = 45) following baseline MR perfusion imaging and spectroscopy of the hip.Results: Percentage reduction in femoral neck BMDa at 4 years post-baseline was greater in subjects with below median acetabulum enhancement slope (E(slope)) (-5.6 ± 1.2 Vs -1.1 ± 1.2 (mean ± standard error) p = 0.014) or muscle maximum enhancement (E(max)) (-5.7 ± 1.2 Vs -0.23 ± 1.2, p = 0.009) after adjusting for baseline co-variables. Baseline MR parameters correlated with reduction in BMDa at 4 years (acetabulum E(slope) r = 0.517, p = 0.0003; muscle E(max) r = 0.306, p = 0.043) as well as traditionally applied clinical risk factors. Acetabulum E(slope), femoral neck E(max) and marrow fat content at baseline had sensitivities of 89%, 81% and 72% respectively at distinguishing between fast (>1%/annum) (n = 18) and slow (<1%/annum) (n = 27) BMD losers.Conclusion: Elderly female subjects with reduced perfusion indices at baseline had increased femoral neck bone loss at 4 years. Selected perfusion indices and marrow fat content have a moderate to high sensitivity in discriminating between fast and slow bone losers. [ABSTRACT FROM AUTHOR]

Objective: To investigate the role of diffusion-weighted imaging (DWI) in predicting and monitoring chemoradiotherapy response in head and neck squamous cell carcinoma (HNSCC).Methods: Diffusion-weighted imaging was performed pre-treatment (n = 50), intra-treatment (n = 41) and post-treatment (n = 20). Apparent diffusion coefficient (ADC) values were correlated with locoregional failure (LF).Results: Locoregional failure occurred in 20/50 (40%) patients. A significant correlation was found between LF and post-treatment ADC (p = 0.02) but not pre- or intra-treatment ADC. Serial change in ADC was even more significant (p = 0.00001), using a fall in ADC early (pre- to intra-treatment) or late (intra- to post-treatment) to indicate LF, achieved 100% specificity, 80% sensitivity and 90% accuracy.Conclusions: Single ADC measurements pre- or intra-treatment did not predict response, but ADC post-treatment was a marker for LF. Serial change in ADC was an even stronger marker, when using an early or late treatment fall in ADC to identify LF. [ABSTRACT FROM AUTHOR]

Elevated choline (Cho) level has been documented on proton magnetic resonance spectroscopy ((1)H MRS) in head and neck squamous cell carcinoma and therefore percentage changes in Cho levels after chemoradiotherapy may serve as a marker of residual cancer in a post-treatment mass (PTM). Forty-six patients underwent (1)H MRS before treatment and the 30 patients with a PTM underwent repeat (1)H MRS at 6 weeks post-treatment. The percentage change in Cho/creatine and Cho/water ratios were correlated with residual cancer. The mean pretreatment Cho/creatine and Cho/water ratios were 2.24 and 1.20 x 10(-3), respectively. Cho persisted in four out of nine PTMs with residual cancer. Cho was absent in five out of nine PTMs with residual cancer and 21/21 PTMs without cancer. The number of PTMs with persistent Cho was too small to allow analysis of percentage change in ratios but the presence of Cho in a PTM showed significant correlation with residual cancer (p = 0.0046), producing a sensitivity, specificity, positive predictive value and negative predictive value of 44%, 100%, 100% and 81%, respectively. Therefore, the presence of Cho in a PTM may serve as a marker of residual cancer. Furthermore since so few PTMs contain Cho, a percentage change in Cho ratios may not be a useful method for monitoring treatment response. [ABSTRACT FROM AUTHOR]

Purpose: To determine the reproducibility of proton ((1)H) magnetic resonance (MR) spectroscopy and dynamic contrast-enhanced MR imaging in a clinical setting for the assessment of marrow fat fraction and marrow perfusion in longitudinal studies.Materials and Methods: In all, 36 subjects (17 females, 19 males, mean age 72.9 +/- 2.9 years) who underwent MR spectroscopy and/or dynamic contrast-enhanced perfusion imaging of the proximal femur were asked to return after 1 week for a repeat MR examination.Results: Reproducibility of (1)H MR spectroscopy in all bone areas tested was high, ranging from 0.78-0.85, with the highest reproducibility being in the femoral head and lowest in the femoral neck. Reproducibility of paired perfusion measurements ranged from 0.59 (enhancement slope femoral head) to 0.98 (enhancement maximum acetabulum). Overall reproducibility of (1)H MR spectroscopy and dynamic contrast-enhanced imaging tended to be best in areas with the highest inherent fat fraction or perfusion.Conclusion: Reproducibility of (1)H MR spectroscopy or perfusion imaging is sufficiently high to warrant these techniques being applied to the longitudinal study of bone diseases. [ABSTRACT FROM AUTHOR]

Peripheral quantitative CT (pQCT) is the main method of bone mineral density (BMD) measurement in small animals. However, pQCT is usually only available in specialized centers, while clinical multidetector computed tomography (MDCT) is much more widely available. This study investigated the feasibility of using clinical 64-slice MDCT for measuring the BMD of rat lumbar vertebrae. The lumbar vertebrae of 18 7-month-old female Sprague-Dawley rats were studied. Two MDCT protocols (General Electric LightSpeed), comprising single 2.5-mm and continuous 0.625-mm acquisitions, and a single pQCT protocol (Scanco Densiscan 2000), comprising 1-mm acquisitions, were performed. The following comparisons were carried out: 2.5-mm MDCT densitometry versus 0.625-mm MDCT densitometry; 0.625-mm MDCT densitometry compared to pQCT densitometry; same day repeatability of 0.625-mm MDCT densitometry; longitudinal repeatability of 0.625-mm MDCT densitometry on day 0 and day 28 and longitudinal 0.625-mm MDCT densitometry in ovariectomized rats on day 0 and day 28. Comparisons were made using intra-class correlation coefficient (ICC). Examination time per animal was 5 min for MDCT and 30 min for pQCT. Acquisitions of 2.5-mm MDCT had a larger coefficient of variation (CoV) than 0.625-mm acquisitions. MDCT densitometry had good agreement with pQCT densitometry (ICC = 0.85). Same-day MDCT densitometry with 0.625-mm acquisitions had a small CoV (1.61%). MDCT densitometry of non-ovariectomized animals at 28 days showed no BMD change, while MDCT densitometry of ovariectomized animals showed a 13.7 +/- 6.7% BMD reduction at 28 days. Clinical MDCT can reliably and accurately measure rat lumbar vertebral BMD and is much faster than pQCT. [ABSTRACT FROM AUTHOR]

AIM: To devise a method to convert the time-intensity curves (TICs) of head and neck dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data into a pixel-by-pixel colour-coded map for identifying normal tissues and tumours. MATERIALS AND METHODS: Twenty-three patients with head and neck squamous cell carcinoma (HNSCC) underwent DCE-MRI. TIC patterns of primary tumours, metastatic nodes, and normal tissues were assessed and a program was devised to convert the patterns into a classified colour-coded map. The enhancement patterns of tumours and normal tissue structures were evaluated and categorized into nine grades (0-8) based on the predominance of coloured pixels on maps. RESULTS: Five identified TIC patterns were converted into a colour-coded map consisting of red (maximum enhancement), brown (continuous slow rise-up), yellow (rapid wash-in and wash-out), green (rapid wash-in and plateau), and blue (rapid wash-in and rise-up). The colour-coded map distinguished all 21 primary tumours and 15 metastatic nodes from normal structures. Primary tumours and metastatic nodes were colour coded as predominantly yellow (grades 1-2) in 17/21 and 6/15, green (grades 3-5) in 3/21 and 5/15, and blue (grades 6-7) in 1/21 and 4/15, respectively. Vessels were coded red in 46/46 (grade 0) and muscles were coded brown in 23/23 (grade 8). Salivary glands, thyroid glands, and palatine tonsils were coded into predominantly yellow (grade 1) in 46/46 and 10/10 and 18/22, respectively. CONCLUSION: DCE-MRI derived five-colour-coded mapping provides an objective easy-to-interpret method to assess the dynamic enhancement pattern of head and neck cancers. [ABSTRACT FROM AUTHOR]

Background & Aims: Although the association between fatty pancreas and metabolic syndrome has been suggested in retrospective studies, long-term prospective data on the effect of fatty pancreas on various metabolic outcomes are lacking. We aimed to prospectively investigate the association between fatty pancreas and the development of major metabolic outcomes., Methods: A total of 631 subjects from a population study using fat-water magnetic resonance imaging to quantify pancreatic and liver fat content during 2008 to 2010 were followed up prospectively until December 2020 (mean follow-up time, 11.1 ± 1.1 y). Subjects with significant alcohol intake and diabetes mellitus (DM) at baseline were excluded. Incidence of newly diagnosed DM, hypertension, dyslipidemia, ischemic heart disease, cardiovascular accidents, pancreatic cancer, and mortality were evaluated., Results: Among the 631 subjects (mean age, 48 ± 11 y), 93 (14.7%) had fatty pancreas. The fatty pancreas group had a higher incidence of DM (33.3% vs 10.4%; P < .001), hypertension (37.7% vs 22.7%; P = .003), and dyslipidemia (37.7% vs 14.6%; P < .001) during long-term follow-up evaluation. Individuals with both fatty liver and pancreas had the highest DM incidence, followed by fatty liver only and fatty pancreas only groups (P < .001). Fatty pancreas was associated independently with DM (adjusted hazard ratio, 1.81; 95% CI, 1.10-3.00; P = .020), but not hypertension or dyslipidemia on multivariate analysis. Each percentage increase of pancreatic fat increased the risk of incident DM by 7% (adjusted hazard ratio, 1.07; 95% CI, 1.01-1.13; P = .016). No participants developed pancreatic cancer during the follow-up period., Conclusions: Fatty pancreas is associated independently with subsequent DM development, but not hypertension or dyslipidemia., (Copyright © 2022 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the value of pre-treatment amide proton transfer-weighted (APTw) imaging for predicting survival of patients with nasopharyngeal carcinoma (NPC)., Materials and Methods: Pre-treatment APTw imaging was performed in 77 NPC patients and the mean, 90th percentile, skewness, and kurtosis of APT asymmetry (APT mean , APT 90 , APT skewness , and APT kurtosis , respectively) were obtained from the primary tumor. Associations of APTw parameters with locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) after 2 years were assessed by univariable Cox regression analysis and significant APTw parameters, together with age, sex, treatment, and stage as confounding variables, were added to the multivariable model. Kaplan-Meier analysis was used to determine the prognostic significance of patients with high or low APT values based on a threshold value from receiver operating characteristic curve analysis., Results: Locoregional relapse, distant metastases, and disease relapse occurred in 14/77 (18%), 10/77 (13%), and 20/77 (26%) patients, respectively, at a median follow-up of 48.3 (10.6-67.4) months. Univariable analysis showed significant associations of LRRFS with APT skewness (HR = 1.98; p = 0.034), DMFS with APT mean (HR = 2.44; p = 0.033), and APT 90 (HR = 1.93; p = 0.009), and DFS with APT mean (HR = 2.01; p = 0.016), APT 90 (HR = 1.68; p = 0.009), and APT skewness (HR = 1.85; p = 0.029). In multivariable analysis, the significant predictors for DMFS were APT 90 (HR = 3.51; p = 0.004) and nodal stage (HR = 5.95; p = 0.034) and for DFS were APT 90 (HR = 1.97; p = 0.010) and age (HR = 0.92; p = 0.014). An APT 90 ≥ 4.38% was associated with a significantly poorer DFS at 2 years than APT 90 < 4.38% (66% vs. 91%; HR = 4.01; p = 0.005)., Conclusion: APTw imaging may potentially predict survival in patients with NPC., Key Points: • APTw imaging may provide new markers to predict survival in nasopharyngeal carcinoma. • APT 90 is an independent predictor of distant metastases-free survival and disease-free survival. • The APT high group is at higher risk of disease relapse than the APT low group.

Purpose: To evaluate whether pre-treatment intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) can predict treatment outcome after 2 years in patients with nasopharyngeal carcinoma (NPC)., Method: One hundred and sixty-one patients with newly diagnosed NPC underwent pre-treatment IVIM-DWI. Univariate Cox regression analysis was performed to evaluate the correlation of the mean values of the pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction and apparent diffusion coefficient with local relapse-free survival (LRFS), regional relapse-free survival (RRFS), distant metastases-free survival (DMFS) and disease-free survival (DFS). Significant diffusion parameters, together with staging, age, gender and treatment as confounding factors, were added into a multivariate model. The area under the curves (AUCs) of significant parameters for disease relapse were compared using the Delong test., Results: Disease relapse occurred in 30 % of the patients at a median follow-up time of 52.1 months. The multivariate analysis showed that high D and T-staging were correlated with poor LRFS (p = 0.042 and 0.020, respectively) and poor DFS (p = 0.023 and 0.001, respectively); low D* and high T-staging with poor RRFS (p = 0.020 and 0.033, respectively); and high N-staging with poor DMFS (p = 0.006). D with the optimal threshold of ≥0.68 × 10 -3  mm 2 /s and T-staging showed similar AUCs (AUC = 0.614 and 0.651, respectively; p = 0.493) for predicting disease relapse., Conclusion: High D and low D* were predictors of poor locoregional outcome but none of the diffusion parameters predicted DMFS in NPC., Competing Interests: Declaration of Competing Interest The authors of this manuscript declare no financial or other conflicts of interest with the publication of this work., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: To determine if treatment of nasopharyngeal carcinoma (NPC) induces early changes in amide proton transfer-weighted (APTw) magnetic resonance imaging (MRI), and to perform a preliminary evaluation of APTw imaging in response assessment., Methods: Sixteen patients with NPC planned for treatment with radiotherapy and/or chemotherapy underwent APTw imaging of the primary tumour pre-treatment and 2-week intra-treatment. Difference in pre- and intra-treatment APT mean (APT mean ) was compared using the Wilcoxon signed rank test. Differences in APT mean and percentage change (%Δ) in APT mean were compared between responders and non-responders based on the outcome at 6 months, using the Mann-Whitney U test., Results: APT mean decreased in 9/16 (56.3%) and increased in 7/16 (43.7%) with no significant difference between the pre- and intra-treatment APT values for the whole group (p > 0.05). NPC showed response in 11/16 (68.8%) and non-response in 5/11 (31.2%). There were significant differences between the %Δ of responders and non-responders for APT mean (p = 0.01). Responders showed %Δ decrease in APT mean of - 23.12% while non-responders showed a %Δ increase in APT mean of + 102.28%., Conclusion: APT value changes can be detected in early intra-treatment. Intra-treatment %Δ APT mean shows potential in predicting short-term outcome.

Objective: To compare the effect of traction during non-arthrographic and arthrographic MR examination of the wrist with regard to joint space width, joint fluid dispersion and cartilage surface visibility., Methods: Prospective 3-T MRI study of 100 wrists in 96 patients. The first 50 wrists underwent MR arthrography first without traction and then with traction. The following 50 wrists underwent standard MR first without traction and then with traction. On these examinations, two radiologists independently measured (i) joint space width, semi-quantitatively graded (ii) joint fluid dispersion between opposing cartilage surfaces and (iii) articular cartilage surface visibility. The three parameters were compared between the two groups., Results: Traction led to an increase in joint space width at nearly all joints in all patients (p < 0.05), although more so in the arthrography (∆ = 0.08-0.79 mm, all p < 0.05) than in the non-arthrography (∆ = 0.001-0.61 mm, all p < 0.05) group. Joint fluid dispersion and cartilage surface visibility improved after traction in nearly all joints (p < 0.05) in all patients and more so in the arthographic than in the non-arthrography group., Conclusion: Traction did significantly improve cartilage surface visibility for standard MRI of the wrist although the effect was not as great as that seen with MR arthography or MR arthrography with traction. Advances in knowledge: This is the first study to show the beneficial effect of traction during standard non-arthrography MRI of the wrist and compare the effect of traction between non-arthrographic and arthrographic MRI of the wrist.

Our study aimed to identify diffusion-weighted imaging (DWI) parameters obtained from primary nasopharyngeal carcinoma (NPC) at initial presentation, that can predict patients at risk of distant metastases. One hundred and sixty-four patients underwent pretreatment magnetic resonance imaging and DWI. The apparent diffusion coefficient (ADC) mean , ADC skewness , and ADC kurtosis were obtained by histogram analysis. Univariate and multivariate analyses of these ADC parameters together with primary volume (PV), nodal volume (NV), T stage, N stage and presence of locoregional relapse (LRR) were compared between patients with distant metastases (DM+) and patients without distant metastases (DM-) at 5 years using logistic regression. Twenty-eight out of 164 patients (17.1 %) were DM+ (2.5-60 months) and 136/164 patients were DM- (61.2-119.4 months). Compared to DM- patients, the primary tumour of DM+ patients showed significantly lower ADC skewness (ADC values with the greatest frequency were higher) (p = 0.041), and higher PV (p = 0.022), NV (p < 0.01), T stage (p = 0.023), N stage (p < 0.01) and LRR (p < 0.01). On multivariate analysis the ADC skewness was no longer significant (p = 0.120) and only NV and LRR were independent predictors for DM+ (p = 0.023 and 0.021, respectively). DWI showed that compared to DM- patients, DM+ patients had a significantly lower primary tumour ADC skewness , but at initial presentation NV was the only independent predictor of DM.

Umbilical cord blood-derived mononuclear cell (UCB-MNC) transplants improve recovery in animal spinal cord injury (SCI) models. We transplanted UCB-MNCs into 28 patients with chronic complete SCI in Hong Kong (HK) and Kunming (KM). Stemcyte Inc. donated UCB-MNCs isolated from human leukocyte antigen (HLA ≥4:6)-matched UCB units. In HK, four patients received four 4-μl injections (1.6 million cells) into dorsal entry zones above and below the injury site, and another four received 8-μl injections (3.2 million cells). The eight patients were an average of 13 years after C5-T10 SCI. Magnetic resonance diffusion tensor imaging of five patients showed white matter gaps at the injury site before treatment. Two patients had fiber bundles growing across the injury site by 12 months, and the rest had narrower white matter gaps. Motor, walking index of SCI (WISCI), and spinal cord independence measure (SCIM) scores did not change. In KM, five groups of four patients received four 4-μl (1.6 million cells), 8-μl (3.2 million cells), 16-μl injections (6.4 million cells), 6.4 million cells plus 30 mg/kg methylprednisolone (MP), or 6.4 million cells plus MP and a 6-week course of oral lithium carbonate (750 mg/day). KM patients averaged 7 years after C3-T11 SCI and received 3-6 months of intensive locomotor training. Before surgery, only two patients walked 10 m with assistance and did not need assistance for bladder or bowel management before surgery. The rest could not walk or do their bladder and bowel management without assistance. At about a year (41-87 weeks), WISCI and SCIM scores improved: 15/20 patients walked 10 m ( p = 0.001) and 12/20 did not need assistance for bladder management ( p = 0.001) or bowel management ( p = 0.002). Five patients converted from complete to incomplete (two sensory, three motor; p = 0.038) SCI. We conclude that UCB-MNC transplants and locomotor training improved WISCI and SCIM scores. We propose further clinical trials.

Background and Purpose: Pretreatment prediction of patients with nasopharyngeal carcinoma who will fail conventional treatment would potentially allow these patients to undergo more intensive treatment or closer posttreatment monitoring. The aim of the study was to determine the ability of pretreatment DWI to predict local failure in patients with nasopharyngeal carcinoma based on long-term clinical outcome., Materials and Methods: One hundred fifty-eight patients with pretreatment DWI underwent analysis of the primary tumor to obtain the ADC mean, ADC skewness, ADC kurtosis, volume, and T-stage. Univariate and multivariate analyses using logistic regression were performed to compare the ADC parameters, volume, T-stage, and patient age in primary tumors with local failure and those with local control, by using a minimum of 5-year follow-up to confirm local control., Results: Local control was achieved in 131/158 (83%) patients (range, 60.3-117.7 months) and local failure occurred in 27/158 (17%) patients (range, 5.2-79.8 months). Compared with tumors with local control, those with local failure showed a significantly lower ADC skewness (ADC values with the greatest frequencies were shifted away from the lower ADC range) (P = .006) and lower ADC kurtosis (curve peak broader) (P = .024). The ADC skewness remained significant on multivariate analysis (P = .044). There was a trend toward higher tumor volumes in local failure, but the volume, together with T-stage and ADC mean, were not significantly different between the 2 groups., Conclusions: Pretreatment DWI of primary tumors found that the skewness of the ADC distribution curve was a predictor of local failure in patients with nasopharyngeal carcinoma, based on long-term clinical outcome., (© 2016 by American Journal of Neuroradiology.)

Objective: To assess the effect of axial traction during MR arthrography (MRA) of the elbow joint on joint space widening, contrast dispersion between opposing cartilage surfaces and cartilage surface visibility., Methods: 11 patients with elbow MRA with and without axial traction were prospectively studied. Two radiologists independently measured the elbow joint space width and semi-quantitatively graded contrast material dispersion between the opposing cartilage surfaces as well as the articular cartilage surface visibility before and after traction. The detection and visibility of articular cartilage defects were also compared before and after traction. Patients were instructed to report on pain or any other symptoms during elbow traction., Results: No patient reported discomfort, pain or any other symptoms related to traction on immediate and intermediate-term follow-up. Joint space width increased, more at the radiocapitellar joint space (Δ = 0.63 mm, p = 0.005) than at the ulnotrochlear joint space (Δ = 0.17 mm, p = 0.012), with contrast dispersion into the radiocapitellar joint and cartilage visibility of the radiocapitellar joint space significantly improving after traction (all p < 0.05). All of these parameters also improved at the ulnotrochlear joint, although this did not reach statistical significance. Traction improved the visibility of cartilage defects., Conclusion: This is the first study to evaluate the effect of traction on MRA of the elbow joint. This technique is safe and technically feasible. Traction MRA improves the cartilage surface visibility and cartilage defect visibility., Advances in Knowledge: This technique is safe and technically feasible. Traction MRA improves cartilage surface visibility and cartilage defect visibility.

Background: Little is known about the importance of liver fibrosis and fatty liver in HIV-monoinfected individuals without hepatitis virus co-infection, particularly among the Asian population., Aim: To evaluate prevalence and risk factors for liver fibrosis and fatty liver in Asian HIV-monoinfected individuals., Methods: Eighty asymptomatic HIV-monoinfected individuals (tested negative for HBV/HCV) were compared with 160 matched HIV-uninfected healthy controls. Transient elastography and proton-magnetic resonance spectroscopy ((1) H-MRS) were performed to measure liver stiffness and hepatic steatosis respectively. Blood samples were analysed for metabolic profiles and markers of steatohepatitis (e.g. cytokeratin-18)., Results: All HIV-infected individuals (mean ± s.d. age 54 ± 11 years, male 93%, Chinese 94%; diagnosis median duration 8 (IQR 4-13 years) were stable on anti-retrovirals (PI-based 58.7%, NNRTI-based 25.0% integrase-inhibitors 16.3%); diabetes, dyslipidaemia, and metabolic syndrome were common. Fatty liver disease was detected in 28.7%. There was significantly higher degree of liver stiffness [4.9 (IQR 4.1-6.2) kPa vs. 4.2 (IQR 3.6-5.0) kPa, P < 0.001], and greater proportions developed significant fibrosis (7.0 kPa, 14.3% vs. 3.1%, P = 0.001) and cirrhosis (10.3 kPa, 5.2% vs. 0.6%, P = 0.040) compared with controls. HIV infection was an independent risk factor for significant fibrosis (adjusted OR 4.00, 95% CI 1.29-12.41, P = 0.016). HIV-infected individuals with fatty liver had excessive liver stiffness and fibrosis. Two cases of asymptomatic hepatocellular carcinoma were detected., Conclusions: HIV-monoinfected patients are at risk for liver fibrosis and cirrhosis. HIV-related mechanisms and fatty liver disease may play important roles. Screening and intervention to prevent severe outcomes should be considered., (© 2016 John Wiley & Sons Ltd.)

Objective: The purpose of this study was to assess the effects of traction during MR arthrography of the wrist on joint space widening, cartilage visibility, and detection of tears of the triangular fibrocartilage complex (TFCC) and intrinsic ligaments., Subjects and Methods: A prospective study included 40 wrists in 39 patients (25 men, 14 women; mean age, 35 years). MR arthrography was performed with a 3-T MRI system with and without axial traction. Two radiologists independently measured wrist and carpal joint space widths and semiquantitatively graded articular cartilage visibility. Using conventional arthrography as the reference standard and working in consensus, they assessed for the presence of tears of the TFCC, lunotriquetral ligament (LTL), and scapholunate ligament (SLL). Visibility of a tear before traction was compared with visibility after traction., Results: With traction, all joint spaces in the wrist and carpus were significantly widened (change, 0.15-1.01 mm; all p < 0.006). Subjective cartilage visibility of all joint spaces improved after traction (all p ≤ 0.048) except for that of the radioscaphoid space, which was well visualized even before traction. Conventional arthrography depicted 24 TFCC tears, seven LTL tears, and three SLL tears. The accuracy of tear detection improved after traction for the TFCC (98% after traction vs 83% before traction), the LTL (100% vs 88%), and the SLL (100% vs 95%). Tear visibility improved after traction for 54% of TFCC tears, 71% of LTL tears, and 66% of SLL tears., Conclusion: Wrist MR arthrography with axial traction significantly improved the visibility of articular cartilage and the detection and visibility of tears of the TFCC and intrinsic ligaments. The results favor more widespread use of traction during MR arthrography of the wrist.

Background and Purpose: It is important to identify patients with head and neck squamous cell carcinoma (SCC) who fail to respond to chemoradiotherapy so that they can undergo post-treatment salvage surgery while the disease is still operable. This study aimed to determine the diagnostic performance of dynamic contrast enhanced (DCE)-MRI using a pharmacokinetic model for pre-treatment predictive imaging, as well as post-treatment diagnosis, of residual SCC at primary and nodal sites in the head and neck., Material and Methods: Forty-nine patients with 83 SCC sites (primary and/or nodal) underwent pre-treatment DCE-MRI, and 43 patients underwent post-treatment DCE-MRI, of which 33 SCC sites had a residual mass amenable to analysis. Pre-treatment, post-treatment and % change in the mean Ktrans, kep, ve and AUGC were obtained from SCC sites. Logistic regression was used to correlate DCE parameters at each SCC site with treatment response at the same site, based on clinical outcome at that site at a minimum of two years., Results: None of the pre-treatment DCE-MRI parameters showed significant correlations with SCC site failure (SF) (29/83 sites) or site control (SC) (54/83 sites). Post-treatment residual masses with SF (14/33) had significantly higher kep (p = 0.05), higher AUGC (p = 0.02), and lower % reduction in AUGC (p = 0.02), than residual masses with SC (19/33), with the % change in AUGC remaining significant on multivariate analysis., Conclusion: Pre-treatment DCE-MRI did not predict which SCC sites would fail treatment, but post-treatment DCE-MRI showed potential for identifying residual masses that had failed treatment.

Despite increasing demand and research efforts, currently there is no consensus on the protocol for automated and reliable quantification of adipose tissue (AT) and visceral adipose tissue (VAT) using MRI. The purpose of this study was to propose a novel computational method with enhanced objectiveness for the quantification of AT and VAT in fat-water separation MRI. 3T data from IDEAL were acquired for the fat-water separation. Fat tissues were separated from nonfat regions (background air, bone, water, and other nonfat tissues) using K-means clustering (K = 2). From the binary fat mask, arm regions were separated from body based on the relative size of connected component. AT was obtained from the binary body fat mask. With the initial contour as the outer boundary of body fat, the subcutaneous adipose tissue (SAT) and VAT were separated using deformable model driven by a specifically generated deformation field pointing to the inner boundary of SAT. The proposed method was tested on 16 patients with dyslipidemia and evaluated by comparing the correlation with semi-automatic segmentation results. Good robustness was also observed in the proposed method from the Bland-Altman plots. Compared to other established fat segmentation methods, the proposed method is highly objective for fat-water separation MRI with minimal variability induced by subjective parameter settings.

Dietary pattern analysis is an alternative approach to examine the association between diet and nonalcoholic fatty liver disease (NAFLD). This study examined the association of two diet-quality scores, namely Diet Quality Index-International (DQI-I) and Mediterranean Diet Score (MDS) with NAFLD prevalence. Apparently healthy Chinese adults (332 male, 465 female) aged 18 years or above were recruited through a population screening between 2008 and 2010 in a cross-sectional population-based study in Hong Kong. DQI-I and MDS, as well as major food group and nutrient intakes were calculated based on dietary data from a food frequency questionnaire. NAFLD was defined as intrahepatic triglyceride content at ≥5% by proton-magnetic resonance spectroscopy. Multivariate logistic regression models were used to examine the association between each diet-quality score or dietary component and prevalent NAFLD with adjustment for potential lifestyle, metabolic and genetic factors. A total of 220 subjects (27.6%) were diagnosed with NAFLD. DQI-I but not MDS was associated with the prevalence of NAFLD. A 10-unit decrease in DQI-I was associated with 24% increase in the likelihood of having NAFLD in the age and sex adjusted model (95% CI: 1.06-1.45, p = 0.009), and the association remained significant when the model was further adjusted for other lifestyle factors, metabolic and genetic factors [OR: 1.26 (95% CI: 1.03-1.54), p = 0.027]. Multivariate regression analyses showed an inverse association of the intake of vegetables and legumes, fruits and dried fruits, as well as vitamin C with the NAFLD prevalence (p<0.05). In conclusion, a better diet quality as characterized by a higher DQI-I and a higher consumption of vegetables, legumes and fruits was associated with a reduced likelihood of having NAFLD in Hong Kong Chinese.

Objectives: Some studies suggest that non-obese patients with nonalcoholic fatty liver disease (NAFLD) may have more severe disease. We aim to study the epidemiology and severity of non-obese NAFLD., Methods: A total of 911 community subjects were randomly recruited from the census database of the Hong Kong Government. Intrahepatic triglycerides (IHTG) and liver fibrosis were assessed by proton-magnetic resonance spectroscopy and transient elastography, respectively. The Asian body mass index cutoff of 25 kg/m(2) was used to define non-obese NAFLD., Results: The prevalence of NAFLD was 19.3% in non-obese subjects and 60.5% in obese subjects (P<0.001). Compared with obese NAFLD patients, non-obese NAFLD patients had similar IHTG content (median 9.8% vs. 9.9%; P=0.100) but lower cytokeratin-18 fragments (149 vs. 182 IU/l; P=0.019) and liver stiffness (4.6 vs. 5.6 kPa; P<0.001). The G allele at the patatin-like phospholipase domain-containing protein 3 gene (PNPLA3 rs738409) was more common in non-obese than obese NAFLD patients (78.4% vs. 59.8%; P=0.001). Obesity, high hemoglobin A1c, insulin resistance, hyperferritinemia, and the PNPLA3 G allele were independent factors associated with NAFLD in non-obese subjects. Even among non-obese subjects with normoglycemia, those with NAFLD were more insulin resistant (mean homeostasis model assessment of insulin resistance: 2.0±1.0 vs. 1.1±1.1; P<0.001)., Conclusions: One-fifth of the general non-obese Chinese population has NAFLD. Non-obese patients with NAFLD do not have a higher risk of steatohepatitis or advanced fibrosis. Patients with risk factors of advanced fibrosis such as metabolic syndrome and PNPLA3 G allele carriage should be assessed for severe NAFLD.

Background: Patients with non-alcoholic steatohepatitis (NASH) have increased intestinal permeability and small intestine bacterial overgrowth., Aims: To test the hypothesis that endotoxemia is associated with non-alcoholic fatty liver disease (NAFLD) in the general population, and to study dietary factors associated with endotoxemia., Methods: Nine hundred and twenty adults were randomly selected from the government's census database and underwent proton-magnetic resonance spectroscopy to assess hepatic steatosis. Endotoxemia was assessed using the limulus amebocyte lysate, lipopolysaccharide-binding protein (LBP) and EndoCab immunoglobulin G (IgG) assays., Results: Two hundred and sixty-three (29%) subjects had NAFLD. Subjects with NAFLD had slightly higher LBP (P < 0.001) and EndoCab IgG (P = 0.013) levels. EndoCab IgG remained an independent factor associated with intrahepatic triglycerides after adjusting for other metabolic factors. Among 565 subjects without NAFLD at baseline who had repeated assessment at a median interval of 47 months, 78 (13.8%) developed incident NAFLD and they also had higher LBP (P = 0.016). Moreover, LBP was associated with insulin resistance and dyslipidaemia, and modestly increased with the cytokeratin-18 fragment level but not liver stiffness measurement by transient elastography. Although total energy consumption and individual macronutrients were not associated with endotoxemia, current drinkers (mostly <140 g/week) had lower endotoxin, EndoCab IgG and fetuin-A levels than nondrinkers., Conclusions: Endotoxin markers are associated with NAFLD in the general population, but do not have a major effect on NASH and fibrosis. People with modest alcohol consumption have lower serum endotoxin. This may partly explain the lower risk of NAFLD and NASH in modest drinkers in previous observational studies., (© 2015 John Wiley & Sons Ltd.)

Objective: To compare the assessment of wrist synovitis severity, synovial volume and synovial perfusion parameters on a dedicated low-field (0.25-T) to that of a high-field (3-T) whole-body MR system in patients with rheumatoid arthritis (RA)., Methods: Twenty-one patients (mean age 50.0 ± 9.8 years) with active RA were recruited prospectively. Dynamic contrast-enhanced MRI examination of the most severely affected wrist was performed at both 0.25 T and 3 T. Three MRI-derived parameters, synovitis severity (RAMRIS grade), synovial volume (ml(3)) and synovial perfusion indices (maximum enhancement and enhancement slope), were compared., Results: Comparing 0.25- and 3-T MRI, there was excellent agreement for semiquantitative assessment (r: 0.80, p < 0.00001) of synovitis (RAMRIS) as well as quantitative assessment (r: 0.94, p < 0.00001) of synovial volume. Good agreement for synovial Emax (r: 0.6, p = 0.002) and fair agreement (r: 0.5, p = 0.02) for synovial Eslope was found., Conclusions: Imaging of the RA wrist at 0.25 T yields excellent correlation with 3 T with regard to the synovitis activity score (RAMRIS) and synovial volume measurement. Fair to good correlation between low- (0.25-T) and high-field (3-T) MR systems was found for perfusion parameters, being better for Emax than for Eslope.

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.)

Nonalcoholic fatty liver disease (NAFLD) has been associated with reduced growth hormone levels and signaling. Such hormonal changes also occur in metabolic acidosis. Since mild metabolic acidosis can be diet induced, diet-induced acid load may constitute a nutritional factor with possible influence on NAFLD development. This study explored whether a higher diet-induced acid load is associated with an increased likelihood of NAFLD. Apparently healthy Chinese adults (330 male, 463 female) aged 19-72 years were recruited through population screening between 2008 and 2010 in a cross-sectional population-based study in Hong Kong. Estimated net endogenous acid production (NEAP) was calculated using Frassetto's method and potential renal acid load (PRAL) was calculated using Remer's method based on dietary data from a food frequency questionnaire. NAFLD was defined as intrahepatic triglyceride content at >5% by proton-magnetic resonance spectroscopy. Possible advanced fibrosis was defined as liver stiffness at >7.9 kPa by transient elastography. Multivariate logistic regression models were used to examine the association between each measure of dietary acid load and prevalent NAFLD or possible advanced fibrosis with adjustment for potential anthropometric and lifestyle factors. 220 subjects (27.7%) were diagnosed with NAFLD. Estimated NEAP was positively associated with the likelihood of having NAFLD after adjustment for age, sex, body mass index, current drinker status and the presence of metabolic syndrome [OR (95% CI) = 1.25 (1.02-1.52), p = 0.022]. The association was slightly attenuated but remained significant when the model was further adjusted for other dietary variables. No association between PRAL and NAFLD prevalence was observed. Both estimated NEAP and PRAL were not associated with the presence of possible advance fibrosis. Our findings suggest that there may be a modest association between diet-induced acid load and NAFLD. More studies are needed to ascertain the link between diet-induced acid load and NAFLD and to investigate the underlying mechanisms.

Background & Aims: Because abdominal ultrasonography cannot reliably quantify hepatic steatosis, accurate data on the incidence of non-alcoholic fatty liver disease (NAFLD) are lacking. We aimed to study the population incidence of NAFLD with state-of-the-art non-invasive tests., Methods: This was a prospective cohort study. The intrahepatic triglyceride (IHTG) content was measured serially with proton-magnetic resonance spectroscopy in community subjects. Transient elastography was performed to assess liver fibrosis., Results: 565 subjects (mean age 48 years, 62.7% women) without NAFLD at baseline underwent follow-up assessment after a median interval of 47 months (range 34-60 months). 78 (13.8%) subjects developed incident fatty liver with a mean IHTG content of 8.9% (SD 5.3%). 16 (20.5%) subjects had an IHTG content ⩾ 11.0% suggestive of moderate to severe steatosis. After excluding 2 men with significant alcohol consumption, the population incidence of NAFLD at 3-5 years was 13.5% (95% CI 10.6-16.3%; 3.4% per year). Only 1 subject with incident NAFLD had high liver stiffness (11.1 kPa) suggestive of advanced fibrosis. Metabolic syndrome at baseline was the strongest predictor of incident fatty liver. Incident central obesity developed in 31.0% of subjects with incident fatty liver and 5.6% of those without (p<0.001). No subject with incident fatty liver had regression of impaired fasting glucose, which occurred in 51.1% of those without incident fatty liver (p=0.001)., Conclusions: 13.5% of the Hong Kong Chinese adult population develop NAFLD in 3-5 years, but few have severe steatosis or advanced fibrosis. Metabolic syndrome is the most important risk factor of incident NAFLD., (Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background and Aim: Lifestyle modification is the cornerstone for the management of nonalcoholic fatty liver disease (NAFLD), and patatin-like phospholipase 3 (PNPLA3) is one of the most important genetic determinants of NAFLD. We aimed to investigate the effect of PNPLA3 gene polymorphism on the response to lifestyle modification in NAFLD patients., Methods: This was a post-hoc analysis of a randomized controlled trial on a lifestyle modification program in community NAFLD patients. The PNPLA3 rs738409 gene polymorphism was correlated with changes in metabolic profile and intrahepatic triglyceride content (IHTG) as measured by proton magnetic resonance spectroscopy., Results: One hundred and fifty-four patients were equally randomized into the intervention and control groups. The presence of G allele was associated with greater reduction in IHTG (CC: 3.7 ± 5.2%, CG: 6.5 ± 3.6%), and GG: 11.3 ± 8.8% (Spearman's correlation, 0.34; P = 0.002), body weight (P = 0.030), waist-to-hip ratio (P = 0.024), total cholesterol (P = 0.031), and low-density lipoprotein cholesterol (P = 0.009) in the intervention group. In contrast, PNPLA3 polymorphism had no impact on IHTG changes in the control group. By multivariable analysis, PNPLA3 genotype and body mass index (BMI) change were independently associated with IHTG reduction in the intervention group. Only BMI change was associated with IHTG reduction in the control group., Conclusion: Although the PNPLA3 rs738409 GG genotype confers a higher risk of NAFLD, these patients are more sensitive to the beneficial effects of lifestyle modification and should be encouraged to do so., (© 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Objective: Bilateral oophorectomy leads to reduced bone mineral density (BMD), and reduced BMD is associated with increased marrow fat and reduced marrow perfusion. Purpose of this study was to investigate how soon these changes occur following surgical oophorectomy., Materials and Methods: Six patients who underwent hysterectomy and bilateral salpingo-oophorectomy were studied. At baseline, mean patient age was 49.5 years (range: 45-54 years). Third lumbar vertebral body BMD measurement using quantitative CT, marrow fat fraction (FF) using MR spectroscopy and marrow perfusion using dynamic contrast enhanced MRI were conducted immediately prior to surgery and at 3, 9, and 21 months after surgery., Results: Reduced BMD, increased marrow FF, and reduced marrow perfusion occurred synchronously post-oophorectomy. There was a sharp decrease of 12.5 ± 7.2% in BMD (n = 6), a sharp increase of 92.2 ± 46.3% (n = 6) in FF, a sharp decrease of 23.6 ± 3.9% in maximum contrast enhancement (n = 5), and of 45.4 ± 7.7% for enhancement slope (n = 5) during the initial 3 months post surgery. BMD and marrow perfusion continued to decrease, and marrow FF continued to increase at a slower rate during the following 18 months. Friedman test showed a significant trend for these changes (p < 0.05)., Conclusion: Bilateral oophorectomy leads to a rapid decrease in lumbar BMD, an increase in marrow fat content, and a decrease in marrow blood perfusion.

We studied the gender gap in life expectancy (GGLE), which currently favours women on average by 5 years. Individual data from 54 societies were extracted from the 1999-2004 wave of the World Values Survey. The GGLE was not predicted by the socio-economic factors of gross domestic product (GDP) or Gini coefficient, but was increased by national level of alcohol consumption, and decreased by gender differences in national levels of life satisfaction. Different national-level phenomena appear to be responsible for male and female contributions to the GGLE. National levels of male longevity were responsive to GDP, Gini coefficient, social engagement, tobacco use and life satisfaction, whereas female longevity rates were responsive only to GDP and alcohol consumption, underscoring the greater sensitivity of male longevity to contextual features of the nations where they live.

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.)

Objectives: Nonalcoholic fatty liver disease is the most common chronic liver disease. Fatty pancreas has also been described but is difficult to assess. It is now possible to measure pancreatic and liver fat accurately with magnetic resonance imaging (MRI). We aimed to define the normal range of pancreatic fat and identify factors associated with fatty pancreas. In addition, the effect of fatty liver and fatty pancreas on insulin resistance (IR) and pancreatic β-cell function was studied., Methods: Fat-water MRI and proton-magnetic resonance spectroscopy were performed on 685 healthy volunteers from the general population to measure pancreatic and liver fat, respectively. On the basis of fasting plasma glucose and insulin levels, the IR and β-cell function were assessed using the homeostasis model assessment (HOMA)., Results: Among subjects without significant alcohol consumption or any component of metabolic syndrome, 90% had pancreatic fat between 1.8 and 10.4%. Using the upper limit of normal of 10.4%, 110 (16.1%; 95% confidence interval 13.3-18.8%) subjects had fatty pancreas. On multivariable analysis, high serum ferritin, central obesity, and hypertriglyceridemia were independent factors associated with fatty pancreas. Subjects with both fatty pancreas and fatty liver had higher HOMA-IR than did those with either condition alone. Fatty pancreas was not associated with HOMA-β after adjusting for liver fat and body mass index., Conclusions: In all, 16.1% of this community cohort of adult Hong Kong Chinese volunteers had a fatty pancreas by our definition. Central obesity, hypertriglyceridemia, and hyperferritinemia are associated with fatty pancreas. Individuals with fatty pancreas have increased IR.

Background & Aims: Liver biopsy is the gold standard for diagnosing non-alcoholic fatty liver disease (NAFLD) but with practical constraints. Phosphorus magnetic resonance spectroscopy ((31)P-MRS) allows in vivo assessment of hepatocellular metabolism and has shown potential for biochemical differentiation in diffuse liver disease. Our aims were to describe spectroscopic signatures in biopsy-proven NAFLD and to determine diagnostic performance of (31)P-MRS for non-alcoholic steatohepatitis (NASH)., Methods: (31)P-MRS was performed in 151 subjects, comprised of healthy controls (n=19) and NAFLD patients with non-NASH (n=37) and NASH (n=95). Signal intensity ratios for phosphomonoesters (PME) including phosphoethanolamine (PE), phosphodiesters (PDE) including glycerophosphocholine (GPC), total nucleotide triphosphate (NTP) including α-NTP, and inorganic phosphate (Pi), expressed relative to total phosphate (TP) or [PME+PDE] and converted to percentage, were obtained., Results: Compared to controls, both NAFLD groups had increased PDE/TP (p<0.001) and decreased Pi/TP (p=0.011). Non-NASH patients showed decreased PE/[PME+PDE] (p=0.048), increased GPC/[PME+PDE] (p<0.001), and normal NTP/TP and α-NTP/TP. Whereas, NASH patients had normal PE/[PME+PDE] and GPC/[PME+PDE], but decreased NTP/TP (p=0.004) and α-NTP/TP (p<0.001). The latter was significantly different between non-NASH and NASH (p=0.047) and selected as discriminating parameter, with area under the receiver-operating characteristics curve of 0.71 (95% confidence interval, 0.62-0.79). An α-NTP/TP cutoff of 16.36% gave 91% sensitivity and cutoff of 10.57% gave 91% specificity for NASH., Conclusions: (31)P-MRS shows distinct biochemical changes in different NAFLD states, and has fair diagnostic accuracy for NASH., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background: The rs738409 GG variant in patatin-like phospholipase 3 (PNPLA3) is associated with non-alcoholic fatty liver disease (NAFLD) and disease severity. However, it remains unclear if it contributes to the development of NAFLD through affecting dietary pattern., Aim: To examine the association among PNPLA3 gene polymorphism, dietary pattern, metabolic factors and NAFLD., Methods: Liver fat and fibrosis were assessed by proton-magnetic resonance spectroscopy and transient elastography in 920 subjects from a population screening project (251 had NAFLD). Dietary nutrient intake was recorded using a locally validated food-frequency questionnaire., Results: The prevalence of GG genotype in NAFLD subjects was 20.7%, compared to 10.6% in controls (P < 0.001). Macronutrient intake was similar among subjects with different PNPLA3 genotypes. The presence of G allele was a predictor of NAFLD independent of nutrient intake and other metabolic factors (adjusted odds ratio to CC: CG, 2.00; GG, 2.68). In subjects without metabolic syndrome, G allele was even more closely correlated with NAFLD diagnosis (adjusted odds ratio to CC: CG, 2.22; GG, 3.39). The prevalence of NAFLD was only 12% in subjects with CC genotype and no metabolic syndrome, and increased to 34% in those with GG genotype and no metabolic syndrome. While NAFLD subjects had significantly lower fibre intake, there was no significant interaction between PNPLA3 and dietary pattern., Conclusions: The G allele in PNPLA3 rs738409 increases the risk of NAFLD in the general population, especially in subjects without metabolic syndrome, independent of dietary pattern and metabolic factors., (© 2014 John Wiley & Sons Ltd.)

Purpose: To technically investigate the non-Gaussian diffusion of head and neck diffusion weighted imaging (DWI) at 3 Tesla and compare advanced non-Gaussian diffusion models, including diffusion kurtosis imaging (DKI), stretched-exponential model (SEM), intravoxel incoherent motion (IVIM) and statistical model in the patients with nasopharyngeal carcinoma (NPC)., Materials and Methods: After ethics approval was granted, 16 patients with NPC were examined using DWI performed at 3T employing an extended b-value range from 0 to 1500 s/mm(2). DWI signals were fitted to the mono-exponential and non-Gaussian diffusion models on primary tumor, metastatic node, spinal cord and muscle. Non-Gaussian parameter maps were generated and compared to apparent diffusion coefficient (ADC) maps in NPC., Results: Diffusion in NPC exhibited non-Gaussian behavior at the extended b-value range. Non-Gaussian models achieved significantly better fitting of DWI signal than the mono-exponential model. Non-Gaussian diffusion coefficients were substantially different from mono-exponential ADC both in magnitude and histogram distribution., Conclusion: Non-Gaussian diffusivity in head and neck tissues and NPC lesions could be assessed by using non-Gaussian diffusion models. Non-Gaussian DWI analysis may reveal additional tissue properties beyond ADC and holds potentials to be used as a complementary tool for NPC characterization.

This study examined the BOLD effect on calf muscles in elderly subjects with different bone mineral density. The purpose was to investigate the oxygenation characteristics in different calf muscle groups for the elderly females and compare the muscle oxygenation among groups with different bone mineral density. Temporary vascular occlusion was induced with air-cuff compression of the thigh and BOLD-MRI data curve was fitted to derive quantitative parameters. Three muscle groups, gastrocnemius muscle (lateral head), soleus muscle, and tibialis anterior muscle, were investigated individually. Quantitative CT measurement was conducted on each subject, based on which subjects were classified into normal, osteopenia, and osteoporosis groups. The BOLD signal in soleus muscle showed the lowest minimum ischemic value during ischemia and the steepest slope during hyperemia. As soleus muscle is mainly composed by slow-twitch oxidative muscle fibers, current results may be due to a higher vascular bed density and better endothelial function in such muscle. By t-test, the half-life of the BOLD signal decay during ischemia in both gastrocnemius and soleus muscles was significantly prolonged in osteoporosis group, indicating a degenerated muscular oxygen metabolic capacity in osteoporotic patients.

Purpose: This study investigated the volumetric relationship of white matter lesion (WML) and contrast-enhanced lesion (CEL) in delayed radiation brain injury (RBI) during the course of evolution., Materials and Methods: MRI results in 45 patients with RBI after receiving radiation for nasopharyngeal carcinoma were analyzed. In total there were 75 lobes with RBI and 114 MRI examinations in this study. WML and CEL lesion volumes were measured. The lesion volume change of less than 5% or 0.25 cm(3) was regarded as being static., Results: The average WML volume was 16.33 cm(3) (ranging 0.11 cm(3) to 102.83 cm(3)), and the average CEL volume was 3.15 cm(3) (ranging 0.03 cm(3) to 27.85 cm(3)). WML was larger than CEL in 164 measurements, and CEL was larger than WML in 10 measurements. In 64.3% follow-ups WML and CEL evolved in the same pattern; and in most follow-ups (93.8%) WML and CEL did not evolve in the opposite directions. A larger WML volume tended to have a larger CEL volume though this relationship was not linear., Conclusion: Evolution of WML and CEL tended to follow the same pattern. WML tended to be larger than CEL, and larger WML tended to be associated with larger CEL.

Purpose: To investigate whether compressed air during air-cuff inflation in vascular reactivity studies could induce aberrant blood oxygenation level-dependent (BOLD) signal change., Materials and Methods: Magnetic resonance imaging (MRI) experiments were performed on a whole-body 3 T scanner. The pattern of T2* signal change measured from a phantom simulating the lower limb was assessed while a thigh cuff was inflated and deflated. MR spectroscopy was performed on a head phantom wrapped using a hand-cuff to determine the relationship between water peak linewidth and applied cuff pressure. Calf muscles from 14 normal subjects were examined to identify aberrant T2* signal changes in the occluded and nonoccluded legs., Results: A sudden T2* signal drop was observed in the phantom on initiation of cuff inflation with subsequent signal change being dependent on cuff pressure. Water peak linewidth increased linearly with cuff pressure (r(2) = 0.94). Aberrant T2* signal changes were observed in both the occluded and nonoccluded legs., Conclusion: Compressed air due to cuff inflation directly affects local magnetic field susceptibility. The T2* sequence is sensitive to local field disturbances induced by an inflated cuff. Muscle BOLD results are affected by high-pressure air, with a sudden drop in T2* signal being a characteristic feature of this induced effect., (Copyright © 2012 Wiley Periodicals, Inc.)

Background & Aims: Healthy lifestyle is the most important management of non-alcoholic fatty liver disease (NAFLD). This study aimed at assessing the efficacy of a community-based lifestyle modification programme in the remission of NAFLD., Methods: This was a parallel group, superiority, randomized controlled trial. 154 adults with NAFLD identified during population screening were randomized to participate in a dietitian-led lifestyle modification programme at 2 community centres or receive usual care for 12 months. The primary outcome was remission of NAFLD at month 12 as evidenced by intrahepatic triglyceride content (IHTG) of less than 5% by proton-magnetic resonance spectroscopy., Results: 74 patients in the intervention group and 71 patients in the control group completed all study assessments. In an intention-to-treat analysis of all 154 patients, 64% of the patients in the intervention group and 20% in the control group achieved remission of NAFLD (difference between groups 44%; 95% CI 30-58%; p<0.001). The mean (SD) changes in IHTG from baseline to month 12 were -6.7% (6.1%) in the intervention group and -2.1% (6.4%) in the control group (p<0.001). Body weight decreased by 5.6 (4.4) kg and 0.6 (2.5) kg in the two groups, respectively (p<0.001). While 97% of patients with weight loss of more than 10% had remission of NAFLD, 41% of those with weight loss of 3.0-4.9% could also achieve the primary outcome., Conclusions: The community-based lifestyle modification programme is effective in reducing and normalizing liver fat in NAFLD patients., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background and Purpose: T2-weighted MRI shows potential in early posttreatment assessment of the primary tumor. Residual masses composed entirely of low T2-signal scar tissue suggest local control and those ≥1 cm of similar signal to untreated tumor suggest local failure. The purpose of this study was to investigate the diagnostic accuracy of T2-weighted MR imaging early after chemoradiotherapy for identifying primary tumor treatment failure in squamous cell carcinoma of the head and neck., Materials and Methods: At 6 weeks after treatment, T2-weighted MR images of 37 primary tumors in 37 patients were assessed. Residual masses were divided into 3 patterns: pattern 1 = scar tissue only (flat-edged/retracted mass of low T2 signal intensity); pattern 2 = mass without features described in pattern 1 or 3; and pattern 3 = any pattern that included an expansile mass ≥1 cm of intermediate T2 signal intensity (similar grade of signal intensity to the untreated tumor). T2 patterns were analyzed for local outcome (Fisher exact test) and time to local failure (univariate and multivariate analysis of T2 pattern, age, T stage, and tumor size by use of the Cox regression model)., Results: Residual masses after treatment were present in 34 (92%) of 37 patients. Local failures occurred in residual masses with pattern 1 in 0 (0%) of 14 patients; pattern 2 in 6 (55%) of 11 patients; and pattern 3 in 9 (100%) of 9 patients. Significant associations were found between local control and pattern 1 (P = <.0001; sensitivity, 74%; specificity, 100%; PPV, 100%; NPV, 75%; accuracy, 85%), and between local failure and pattern 3 (P = <.0001; sensitivity, 60%; specificity, 100%; PPV, 100%; NPV, 76%; accuracy, 82%). Pattern 2 showed no significant associations with local outcome. Univariate analysis of time to local failure showed that the T2 pattern was significant (P < .0001) and remained significant on multivariate analysis., Conclusions: T2-weighted MR imaging is a potential tool for early posttreatment assessment of primary HNSCC treatment response. Awareness of correlation of the T2 pattern of any residual mass with treatment outcome at the primary site may contribute to patient treatment.

Purpose: The purpose was to describe the design and fabrication of a driver suitable for magnetic resonance elastography (MRE) of the head and neck and to assess its performance in evaluating human parotid gland, lymph nodes and thyroid at 3.0 T., Materials and Methods: A head and neck driver was fabricated using a commercial transducer, headrest mould and piston extension. Driver performance was tested using a motion-sensitized spin-echo MRE pulse sequence. Six healthy volunteers and three patients (two metastatic nodes and one papillary carcinoma) were evaluated using MRE. Viscoelastic maps were computed to obtain storage modulus (G') and loss modulus (G") of the normal parotid and thyroid, metastatic node and thyroid cancer. Reproducibility was assessed by coefficient of variation., Results: All subjects completed MRE examination without discomfort. Initial G' and G" values were as follows: normal parotid gland, 1.12 kPa and 0.48 kPa; thyroid, 0.58 kPa and 0.42 kPa; metastatic node, 0.66 kPa and 0.58 kPa; and thyroid cancer, 0.17 kPa and 0.28 kPa. Based on parotid data, the coefficient of variation for G' and G" was 4.7% and 9.8%., Conclusion: A new MRE driver for head and neck was successfully implemented, and our initial results suggested the device was suitable for the mechanical assessment of tissues in the head and neck., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The human gut microbiota has profound influence on host metabolism and immunity. This study characterized the fecal microbiota in patients with nonalcoholic steatohepatitis (NASH). The relationship between microbiota changes and changes in hepatic steatosis was also studied., Methods: Fecal microbiota of histology-proven NASH patients and healthy controls was analyzed by 16S ribosomal RNA pyrosequencing. NASH patients were from a previously reported randomized trial on probiotic treatment. Proton-magnetic resonance spectroscopy was performed to monitor changes in intrahepatic triglyceride content (IHTG)., Results: A total of 420,344 16S sequences with acceptable quality were obtained from 16 NASH patients and 22 controls. NASH patients had lower fecal abundance of Faecalibacterium and Anaerosporobacter but higher abundance of Parabacteroides and Allisonella. Partial least-square discriminant analysis yielded a model of 10 genera that discriminated NASH patients from controls. At month 6, 6 of 7 patients in the probiotic group and 4 of 9 patients in the usual care group had improvement in IHTG (P=0.15). Improvement in IHTG was associated with a reduction in the abundance of Firmicutes (R(2)=0.4820, P=0.0028) and increase in Bacteroidetes (R(2)=0.4366, P=0.0053). This was accompanied by corresponding changes at the class, order and genus levels. In contrast, bacterial biodiversity did not differ between NASH patients and controls, and did not change with probiotic treatment., Conclusions: NASH patients have fecal dysbiosis, and changes in microbiota correlate with improvement in hepatic steatosis. Further studies are required to investigate the mechanism underlying the interaction between gut microbes and the liver.

Background: Probiotics have profound effect on nonalcoholic steatohepatitis (NASH) in animal models. We aimed to test the hypothesis that probiotics treatment was superior to usual care in reducing liver fat in NASH patients., Material and Methods: Patients with histology-proven NASH were randomized to receive probiotics (n = 10) or usual care (n = 10) for 6 months. The Lepicol probiotic formula contained Lactobacillus plantarum, Lactobacillus deslbrueckii, Lactobacillus acidophilus, Lactobacillus rhamnosus and Bifidobacterium bifidum. The primary endpoint was change in intrahepatic triglyceride content (IHTG), as measured by proton-magnetic resonance spectroscopy, from baseline to month 6. Secondary endpoints included changes in liver biochemistry and metabolic profile., Results: IHTG decreased from 22.6 ± 8.2% to 14.9 ± 7.0% in the probiotic group (P = 0.034) but remained static in the usual care group (16.9 ± 6.1% to 16.0 ± 6.6%; P = 0.55). Six subjects in the probiotic group had IHTG reduced by more than 30% from baseline, compared to 2 subjects in the usual care group (P = 0.17). The probiotic group also had greater reduction in serum aspartate aminotransferase level (P = 0.008). On the other hand, the use of probiotics was not associated with changes in body mass index, waist circumference, glucose and lipid levels., Conclusions: Probiotics treatment may reduce liver fat and AST level in NASH patients. The therapeutic potential of probiotics in NASH should be tested in larger studies.

Purpose: To determine the diagnostic performance of diffusion-weighted (DW) imaging for the prediction of treatment failure in primary head and neck squamous cell carcinoma (HNSCC)., Materials and Methods: The study was approved by the local institutional ethics committee and conducted with informed written consent in patients with primary HNSCC treated with radiation therapy and chemotherapy. DW imaging of the primary tumor was performed before treatment in 37 patients and was repeated within 2 weeks of treatment in 30 patients. Histograms of apparent diffusion coefficients (ADCs) were analyzed, and mean ADC, kurtosis, skewness, and their respective percentage change were correlated for local failure and local control at 2 years by using the Student t test. Univariate and multivariate analyses of the ADC parameters, T stage, and tumor volume were performed by using logistic regression for prediction of local failure., Results: Local failure occurred in 16 of 37 (43%) patients and local control occurred in 21 of 37 (57%) patients. Pretreatment ADC parameters showed no correlation with local failure. There was significant intratreatment increase in mean ADC and a decrease in skewness and kurtosis (P < .001, P < .001, P = .024, respectively) for the whole group of patients when compared with those before treatment. During treatment, primary tumors showed a significantly lower increase in percentage change of mean ADC, higher skewness, and higher kurtosis for local failure than for local control (P = .016, .015, and .040, respectively). These ADC parameters also were significant for predicting local failure with use of univariate but not multivariate analysis., Conclusion: Early intratreatment DW imaging has the potential to allow prediction of treatment response at the primary site in patients with HNSCC.

Background: Head and neck Magnetic Resonance (MR) Images are vulnerable to the arterial blood in-flow effect. To compensate for this effect and enhance accuracy and reproducibility, dynamic tracer concentration in veins was proposed and investigated for quantitative dynamic contrast-enhanced (DCE) MRI analysis in head and neck., Methodology: 21 patients with head and neck tumors underwent DCE-MRI at 3T. An automated method was developed for blood vessel selection and separation. Dynamic concentration-time-curves (CTCs) in arteries and veins were used for the Tofts model parameter estimations. The estimation differences by using CTCs in arteries and veins were compared. Artery and vein voxels were accurately separated by the automated method. Remarkable inter-slice tracer concentration differences were found in arteries while the inter-slice concentration differences in veins were moderate. Tofts model fitting by using the CTCs in arteries and veins produced significantly different parameter estimations. The individual artery CTCs resulted in large (>50% generally) inter-slice parameter estimation variations. Better inter-slice consistency was achieved by using the vein CTCs., Conclusions: The use of vein CTCs helps to compensate for arterial in-flow effect and reduce kinetic parameter estimation error and inconsistency for head and neck DCE-MRI.

Background: The diagnosis of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH) and fibrosis relies on liver biopsy. Non-invasive assessments are urgently needed., Aim: To evaluate cell apoptotic marker cytokeratin-18 M30 and total cell death markers cytokeratin-18 M65/M65ED for the assessment and monitoring of NAFLD., Methods: A cohort of 147 patients with biopsy-proven NAFLD and 73 controls were enrolled, including 51 patients who received paired liver biopsies 36 months apart. Biomarkers were determined by enzyme-linked immunosorbent assay., Results: M30, M65 and M65ED increased in a stepwise fashion in control subjects, patients with non-NASH, NAFLD and NASH (all P < 0.001). All biomarkers had similarly high accuracy over 0.9 in predicting NAFLD and moderate accuracy around 0.7 in predicting NASH. Among patients with paired liver biopsies, changes in M30, M65 and M65ED positively correlated with disease progression (rho = 0.42, 0.32 and 0.39; P = 0.002, 0.023 and 0.005 respectively), and only changes in M65 and M65ED correlated with fibrosis progression (rho = 0.29, 0.34; P = 0.038, 0.015 respectively). Both M30 and M65 had area under receiver-operating characteristics curve above 0.8 in predicting disease progression. At cut-off of 236 U/L, changes of M65ED had 88% NPV and 59% PPV to exclude and predict fibrosis progression., Conclusions: Cytokeratin-18 M30 and M65/M65ED have moderate accuracy in detecting non-alcoholic steatohepatitis. Changes in the biomarkers also correlate with histological progression. However, development of new biomarkers is still required to improve the diagnostic accuracy., (© 2012 Blackwell Publishing Ltd.)

Purpose: To quantitatively evaluate the kinetic parameter estimation for head and neck (HN) dynamic contrast-enhanced (DCE) MRI with dual-flip-angle (DFA) T1 mapping., Materials and Methods: Clinical DCE-MRI datasets of 23 patients with HN tumors were included in this study. T1 maps were generated based on multiple-flip-angle (MFA) method and different DFA combinations. Tofts model parameter maps of k(ep), K(trans) and v(p) based on MFA and DFAs were calculated and compared. Fitted parameter by MFA and DFAs were quantitatively evaluated in primary tumor, salivary gland and muscle., Results: T1 mapping deviations by DFAs produced remarkable kinetic parameter estimation deviations in head and neck tissues. In particular, the DFA of [2º, 7º] overestimated, while [7º, 12º] and [7º, 15º] underestimated K(trans) and v(p), significantly (P<0.01). [2º, 15º] achieved the smallest but still statistically significant overestimation for K(trans) and v(p) in primary tumors, 32.1% and 16.2% respectively. k(ep) fitting results by DFAs were relatively close to the MFA reference compared to K(trans) and v(p)., Conclusions: T1 deviations induced by DFA could result in significant errors in kinetic parameter estimation, particularly K(trans) and v(p), through Tofts model fitting. MFA method should be more reliable and robust for accurate quantitative pharmacokinetic analysis in head and neck.

Purpose: To investigate vertebral bone marrow fat content in elderly subjects related to sex, age, and bone mineral density (BMD) and relate these findings to published data in younger subjects., Materials and Methods: A total of 259 healthy subjects (145 females, 114 males; age range, 62-90 years) underwent proton ((1) H) MR spectroscopy of L3 vertebral body and BMD of the lumbar spine with results stratified according to age. Ninety age- and BMD-matched subjects were selected to determine sex differences in marrow fat content and BMD., Results: In females, vertebral marrow fat content rose sharply between 55 and 65 years of age while in males vertebral marrow fat content rose gradually throughout life. Vertebral marrow fat content in females more than 60 years was approximately 10% higher in females than males, i.e., a reversal of sex difference reported in marrow fat content for subjects less than 60 years., Conclusion: Marrow fat content increases sharply in female subjects between 55 and 65 years of age while male subjects continue to increase marrow fat at a more gradual steady rate. Females older than 60 years have a higher marrow fat content than males. This increased deposition in marrow fat concurs with recognized changes in extraosseous fat distribution in postmenopausal females., (Copyright © 2012 Wiley Periodicals, Inc.)