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Background: Copper complex has been gaining much attention in anticancer research as a targeted agent since cancer cells uptake more copper than non-cancerous cells. Our group synthesised a ternary copper complex, which is composed of 1,10-phenanthroline and tyrosine [Cu(phen)(L-tyr)Cl].3H20. These two payloads have been designed to cleave DNA and inhibit protein degradation system (proteasome) concurrently in cancer cells, making this copper complex a dual-target compound. Objective: The current study was carried out to investigate the mode of cell death and the role of autophagy induced by [Cu(phen)(L-tyr)Cl].3H20 in MCF-7 and MDA-MB-231 breast cancer cells. Methods: Growth inhibition of [Cu(phen)(L-tyr)Cl].3H20 towards MDA-MB-231 and human non-cancerous MCF10A breast cells was determined by MTT assay. Annexin-V-FITC/PI and cell cycle analysis were evaluated by flow cytometry. The expression of p53, Bax, caspase-9, caspase-7, caspase-3 and LC3 was determined using western blot analysis. The cells were then co-treated with hydroxychloroquine to ascertain the role of autophagy induced by [Cu(phen)(L-tyr)Cl].3H20. Results: [Cu(phen)(L-tyr)Cl].3H20 inhibited the growth of cancer cells dose-dependently with less toxicity towards MCF10A cells. Additionally, [Cu(phen)(L-tyr)Cl].3H20 induced apoptosis and cell cycle arrest towards MCF-7 and MDA-MB-231 breast cancer cells possibly via regulation of p53, Bax, caspase-9, caspase-3 and capase-7. The expression of LC3II was upregulated in both cancer cell lines upon treatment with [Cu(phen)(L-tyr) Cl].3H20, indicating the induction of autophagy. Co-treatment with autophagy inhibitor hydroxychloroquine significantly enhanced growth inhibition of both cell lines, suggesting that autophagy induced by [Cu(phen)(L-tyr) Cl].3H20 in both breast cancer cells promoted cell survival. Conclusion: [Cu(phen)(L-tyr)Cl].3H20 holds great potential to be developed for breast cancer treatment.

Exo-beta-mannosidases are a broad class of stereochemically retaining hydrolases that are essential for the breakdown of complex carbohydrate substrates found in all kingdoms of life. Yet the detection of exo-beta-mannosidases in complex biological samples remains challenging, necessitating the development of new methodologies. Cyclophellitol and its analogues selectively label the catalytic nucleophiles of retaining glycoside hydrolases, making them valuable tool compounds. Furthermore, cyclophellitol can be readily redesigned to enable the incorporation of a detection tag, generating activity-based probes (ABPs) that can be used to detect and identify specific glycosidases in complex biological samples. Towards the development of ABPs for exo-beta-mannosidases, we present a concise synthesis of beta-manno-configured cyclophellitol, cyclophellitol aziridine, and N-alkyl cyclophellitol aziridines. We show that these probes covalently label exo-beta-mannosidases from GH families 2, 5, and 164. Structural studies of the resulting complexes support a canonical mechanism-based mode of action in which the active site nucleophile attacks the pseudoanomeric centre to form a stable ester linkage, mimicking the glycosyl enzyme intermediate. Furthermore, we demonstrate activity-based protein profiling using an N-alkyl aziridine derivative by specifically labelling MANBA in mouse kidney tissue. Together, these results show that synthetic manno-configured cyclophellitol analogues hold promise for detecting exo-beta-mannosidases in biological and biomedical research.

Objective: To investigate the associations between age and clinical and radiological disease activities in axial SpA. Methods: One hundred and twenty-one patients fulfilling the Assessment of SpondyloArthritis International Society Classification Criteria for axial SpA were included in analyses. Patient demographics, disease activity and radiographic scores, as well as magnetic resonance imaging (MRI) with diffusion weighted imaging derived apparent diffusion coefficient values (DWI(ADC)), were compared between patients aged > 40 and [Formula: see text] 40 years at a cross-sectional level. Variables with significant differences in univariate analyses were used as dependent variables in multivariate linear regression models adjusted for potential confounding/contributing factors. Results: Multivariate analysis showed that increasing age was significantly associated with higher Bath Ankylosing Spondylitis Functional Index (B = 0.04, p < 0.01) and Bath Ankylosing Spondylitis Metrology Index scores (B = 0.04, p < 0.01); as well as higher modified Stoke Ankylosing Spondylitis Spine Score (B = 0.41, p < 0.01). On MRI, increasing age was associated with a lower DWI(ADC) (B = (-0.01), p < 0.01) of the SI joints, but higher DWI(ADC) values of the axial spine (B = 0.01, p = 0.01). Conclusion: Increasing age in SpA was associated with greater functional impairment and structural damage, more inflammation of the axial spine, but less inflammation of the SI joints. Our findings are consistent with the traditional belief that SpA is an “ascending disease” and highlights the importance of different modalities of MRI in the diagnosis and disease monitoring of SpA.

One aim of this study is to use non-Gaussian diffusion kurtosis imaging (DKI) for capturing microstructural abnormalities in gray matter of Alzheimer's disease (AD). The other aim is to compare DKI metrics against thickness of cortical gray matter and volume of deep gray matter, respectively. A cohort of 18 patients with AD, 18 patients with amnestic mild cognitive impairment (MCI), and 18 normal controls underwent morphological and DKI MR imaging. Images were investigated using regions-of-interest-based analyses for deep gray matter and vertex-wise analyses for cortical gray matter. In deep gray matter, more regions showed DKI parametric abnormalities than atrophies at the early MCI stage. Mean kurtosis (MK) exhibited the largest number of significant abnormalities among all DKI metrics. At the later AD stage, diffusional abnormalities were observed in fewer regions than atrophies. In cortical gray matter, abnormalities in thickness were mainly in the medial and lateral temporal lobes, which fit the locations of known early pathological changes. Microstructural abnormalities were predominantly in the parietal and even frontal lobes, which fit the locations of known late pathological changes. In conclusion, MK can complement conventional diffusion metrics for detecting microstructural changes, especially in deep gray matter. This study also provides evidence supporting the notion that microstructural changes predate morphological changes. Hum Brain Mapp 38:2495-2508, 2017. © 2017 Wiley Periodicals, Inc.

Early clinical diagnosis of Alzheimer’s disease (AD) is beneficial for medications that delay its progression. However, current diagnosis of AD is still based on the observation of clinical symptoms from the family members and the MMSE score test from the doctors. Since diffusional tensor imaging (DTI) has long been used to detect microstructural changes in cerebral white matter (WM), we conducted a multi-parameter comparison on structures of WM using DTI, aiming to access the relation between neuroanatomical variations and AD onset.

The purpose of this work was to investigate the effects of hemispheric location, gender and age on susceptibility value, as well as the association between susceptibility value and diffusional metrics, in deep gray matter. Iron content was estimated in vivo using quantitative susceptibility mapping. Microstructure was probed using diffusional kurtosis imaging. Regional susceptibility and diffusional metrics were measured for the putamen, caudate nucleus, globus pallidus, thalamus, substantia nigra and red nucleus in 42 healthy adults (age range 25-78 years). Susceptibility value was significantly higher in the left than the right side of the caudate nucleus (P = 0.043) and substantia nigra (P < 0.001). Women exhibited lower susceptibility values than men in the thalamus (P < 0.001) and red nucleus (P = 0.032). Significant age-related increases of susceptibility were observed in the putamen (P < 0.001), red nucleus (P < 0.001), substantia nigra (P = 0.004), caudate nucleus (P < 0.001) and globus pallidus (P = 0.017). The putamen exhibited the highest rate of iron accumulation with aging (slope of linear regression = 0.73 × 10(-3) ppm/year), which was nearly twice those in substantia nigra (slope = 0.40 × 10(-3) ppm/year) and caudate nucleus (slope = 0.39 × 10(-3) ppm/year). Significant positive correlations between the susceptibility value and diffusion measurements were observed for fractional anisotropy (P = 0.045) and mean kurtosis (P = 0.048) in the putamen without controlling for age. Neither correlation was significant after controlling for age. Hemisphere, gender and age-related differences in iron measurements were observed in deep gray matter. Notably, the putamen exhibited the highest rate of increase in susceptibility with aging. Correlations between susceptibility value and microstructural measurements were inconclusive. These findings could provide new clues for unveiling mechanisms underlying iron-related neurodegenerative diseases.

Objective There are potential benefits of repetitive transcranial magnetic stimulation (rTMS) in improving swallowing functions after stroke; however, few studies have been performed in the chronic stroke population. This study aims to distil the key effects of rTMS on swallowing functions and swallowing-related quality of life. Methods Twenty-two participants with chronic post-stroke dysphagia were randomly assigned into active or sham rTMS groups. Seven participants withdrew from the study, thus data from 15 participants (mean age 64.6 years) were analysed. Participants received 3,000 pulses of 5 Hz rTMS (active: n = 11; sham: n = 4) on the tongue area of the motor cortex for 10 days over a period of 2 weeks. All participants were assessed 1 week before, and 2 months, 6 months and 12 months after stimulation. Outcomes were measured by a videofluoroscopic swallowing study, swallowing-related quality-of-life questionnaire and Iowa Oral Performance Instrument. Results No statistically significant effects were identified for any outcome measures. Conclusion This study indicates that 5 Hz rTMS applied over the tongue area of the motor cortex is not effective for improving swallowing function in individuals with chronic post-stroke dysphagia. Possible explanations for these non-significant results are dis cussed. Future studies should explore the potential of the current protocol in conjunction with conventional dysphagia therapy.

Objective We hypothesize that the standardized uptake value (SUV) from PET/computed tomography (CT) can act as an adjunct to forced vital capacity (FVC) in evaluating disease status in idiopathic pulmonary fibrosis (IPF). Methods Eight consecutive male patients diagnosed with IPF were prospectively recruited to undergo full pulmonary function tests, high-resolution computed tomography of the thorax and PET/CT. The corrected mean SUV (rSUVmean) and corrected maximum SUV (rSUVmax) against the mediastinal blood pool were correlated with clinical parameters. Examinations were repeated 6 months later in six patients (2/8 patients had died) and changes were evaluated. Correlation was assessed by Spearman's rank correlation, and statistical significance was considered when the P-value was less than 0.05. Results The rSUVmean in IPF was negatively correlated with FVC (r=-0.6, P=0.024) and diffusing capacity for carbon monoxide (r=-0.7, P=0.010). The decline in FVC was associated with an increment in rSUVmax (r=-0.9, P=0.019), but no similar observation was made with total CT score (r=-0.1, P=0.787). Conclusion Pulmonary metabolism, rSUVmean, contributes to the functional status of IPF patients, and changes in rSUVmax may serve as an adjunct surrogate marker to FVC in evaluating the disease status in IPF patients.

Object Diffusional kurtosis imaging (DKI), a natural extension of diffusion tensor imaging (DTI), can characterize non-Gaussian diffusion in the brain. We investigated the capability of DKI parameters for detecting microstructural changes in both gray matter (GM) and white matter (WM) in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) and sought to determine whether these DKI parameters could serve as imaging biomarkers to indicate the severity of cognitive deficiency. Materials and Methods DKI was performed on 18 AD patients and 12 MCI patients. Fractional anisotropy, kurtosis and diffusivity parameters in the temporal, parietal, frontal and occipital lobes were compared between the two groups using Mann–Whitney U test. The correlations between regional DKI parameters and mini-mental state examination (MMSE) score were tested using Pearson's correlation. Results In ADs, significantly increased diffusivity and decreased kurtosis parameters were observed in both the GM and WM of the parietal and occipital lobes as compared to MCIs. Significantly decreased fractional anisotropy was also observed in the WM of these lobes in ADs. With the exception of fractional anisotropy and radial kurtosis, all the five other DKI parameters exhibited significant correlations with MMSE score in both GM and WM. Conclusion Bearing additional information, the DKI model can provide sensitive imaging biomarkers for assessing the severity of cognitive deficiency in reference to MMSE score and potentially improve early detection and progression monitoring of AD based on characterizing microstructures in both the WM and especially the GM.

Introduction Osteoarthritis (OA) of the knee is a common and disabling disease worldwide. Its prevalence is increasing in view of the aging population. Changes in collagen content, its orientation and GAG content in the articular cartilage with age are the major features in knee osteoarthritis. These changes in collagen and GAG contents show no manifestation in plain radiography and conventional magnetic resonance imaging (MRI). Nevertheless, early diagnosis of the knee osteoarthritis is of paramount importance clinically in view of the evolution of putative interventions in its early stage. The aim of this project is to identify the relationships between the two imaging biomarkers (i.e. T1ρ and T2 mappings) and the GAG concentration in living human symptomatic cartilage. Methodology 28 patients with clinical diagnosis of knee osteoarthritis were enrolled. 7 males and 16 females were recruited and their mean age was 68.1 (ranges from 53 to 84). Conventional PD sequence, T1ρ and T2 mappings were performed for each subject within 1 week before total knee arthroplasty. Articular cartilage from the lateral tibial plateau was harvested and the GAG content in cartilage was determined by using dimethylmethylene blue method. T1ρ mean and T2 values were calculated and correlate with GAG concentration statistically. Results The mean value T1ρ was 40.3 ± 13.5 ms, ranging from 15.3 to 69.3 ms and the mean value T2 was 31.0 ± 10.5 ms, ranging from 16.1 to 46.9 ms. The mean value of GAG content was 80.1 ± 33.3 mg, ranging from 24.9 to 166.0 mg while the mean value of GAG concentration was 267.4 ± 165.9 mg/cm3, ranging from 91.3 to 760.5 mg/cm3. T2 values were inversely correlated with GAG concentration with R2 = 0.375, p = 0.001 while T1ρ values were also inversely correlated with GAG concentration with R2 = 0.200, p = 0.025. Conclusion This in vivo study confirmed that T1ρ and T2 values correlate with the GAG concentration in living human knee cartilages which corroborate with the previous works. The later (T2 values) is found more reliable in our study and less controversial in literatures. We postulate that T2 values can serve as a non-invasive imaging biomarker in the progress of knee osteoarthritis in terms of both disease diagnosis and treatment response monitoring.

To evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for characterising nasopharyngeal carcinoma (NPC). Forty-five newly diagnosed NPC patients were recruited. The initial enhancement rate (E R ), contrast transfer rate (k ep ), elimination rate (k el ), maximal enhancement (MaxEn) and initial area under the curve (iAUC) were calculated from semiquantitative analysis. The K trans (volume transfer constant), v e (volume fraction) and k ep were calculated from quantitative analysis. Student’s t-test was used to evaluate the differences among tumour stages. Pearson’s correlation between the two sets of k ep was performed. Comparing tumours of T1/2 stage (n = 18) and T3/4 stage (n = 27), MaxEn (P = 0.030) and iAUC (P = 0.039) were both significantly different; however, the iAUC was the only independent variable with 69.6 % sensitivity and 76.5 % specificity respectively; v e was also significantly different (P = 0.010) with 69.6 % sensitivity and 70.6 % specificity respectively. No significant difference was found among N stages. The two sets of k ep s were highly correlated (r = 0.809, P

Alzheimer's disease (AD) has become one of the most serious healthcare problems. As a result, early diagnosis for AD is important for intervention of its deterioration at an early stage. Diffusion tensor imaging (DTI) provides a non-intrusive examination of cranial nerve diseases, but the precise quantification is a problem for diagnosis. In current study, we proposed an AD recognition method based on quantitative analysis and data fusion of T1 and DTI images. Through segmentation on T1 image, feature extraction of DTI data, and data fusion based on multi-features, recognition accuracy of AD can attain as high as 95.4%. For details, patterns of different features from DTI data were investigated showing that the fusion of volume values, DTI and diffusion kurtosis imaging (DKI) parameters and the Gaussian Mixture Model (GMM) parameters of DTI and DKI are the most distinctive individual features in AD patients. It also implies that during the AD development, neural degeneration could be demyelination, reduction of structural complexity and decrease of brain microstructure connectivity, which can be reflected by different quantitative parameters from brain images, such as brain structure volume, DTI parameters and DKI parameters. Further study on the image features, including more image types, would provide valued method for AD screening or early diagnosis.

One aim of this study is to use non‐Gaussian diffusion kurtosis imaging (DKI) for capturing microstructural abnormalities in gray matter of Alzheimer's disease (AD). The other aim is to compare DKI metrics against thickness of cortical gray matter and volume of deep gray matter, respectively. A cohort of 18 patients with AD, 18 patients with amnestic mild cognitive impairment (MCI), and 18 normal controls underwent morphological and DKI MR imaging. Images were investigated using regions‐of‐interest‐based analyses for deep gray matter and vertex‐wise analyses for cortical gray matter. In deep gray matter, more regions showed DKI parametric abnormalities than atrophies at the early MCI stage. Mean kurtosis (MK) exhibited the largest number of significant abnormalities among all DKI metrics. At the later AD stage, diffusional abnormalities were observed in fewer regions than atrophies. In cortical gray matter, abnormalities in thickness were mainly in the medial and lateral temporal lobes, which fit the locations of known early pathological changes. Microstructural abnormalities were predominantly in the parietal and even frontal lobes, which fit the locations of known late pathological changes. In conclusion, MK can complement conventional diffusion metrics for detecting microstructural changes, especially in deep gray matter. This study also provides evidence supporting the notion that microstructural changes predate morphological changes. Hum Brain Mapp 38:2495–2508, 2017. © 2017 Wiley Periodicals, Inc.

To investigate the usefulness of diffusion weighted imaging (DWI) by comparing with clinical features, blood parameters and traditional short tau inversion recovery (STIR) sequence in detecting spinal and sacroiliac (SI) joint inflammation in axial spondyloarthritis (axSpA) patients.One hundred and ten axSpA patients were recruited. Clinical, radiological and blood parameters were recorded. DWI and STIR MRI were performed simultaneously and results were scored according to the Spondyloarthritis Research Consortium of Canada (SPARCC) for comparison. Apparent diffusion coef cient (ADC) values were also calculated.DWI did not correlate with clinical parameters or blood parameters. It also had lowered sensitivity. When compared with STIR sequence, it correlated well with STIR sequence at the SI joint level (CC 0.76, p0.001), but weakly at the spinal level (CC 0.23, p=0.02). At the SI joint level, the presence of inflammation on both STIR sequence and DWI was associated with an increase in maximum (B=0.24, p=0.02 in STIR; B=0.37, p0.001 in DWI) and mean ADC values (B=0.17, p=0.003 in STIR; B=0.15, p=0.01 in DWI). Maximum (B=0.19, p=0.04) and mean spinal ADC values (B=0.18, p=0.01) were also positively associated with DWI detected spinal inflammation. Presence of Modic lesions showed positive correlation with STIR sequence (B=7.12, p=0.01) but not spinal ADC values.Despite DWI correlates with STIR sequence, it has lower sensitivity. However, ADC values appear to be independent of Modic lesions and may supplement STIR sequence to differentiate degeneration.

Introduction To assess the awareness of radiation dose and associated risks caused by radiological procedures among local patients. Methods All subjects were recruited by randomly sampling the patients receiving radiological examinations. These subjects were stratified on age, sex and education. The questionnaire was in Chinese and consisted of 28 questions mostly in multiple choice/true-or-false format, divided into three sections examining demographic data, radiation knowledge/awareness and expectations. Results A total of 173 questionnaires were returned (83 females and 84 females; mean age of 53). Of these, 32.6% had attended college, 32.6% had completed matriculation and 24.4% secondary school. Most subjects underwent CT (75), MRI (70) and PET-CT (18). Education significantly affected the radiation knowledge (P = 0.013). 60.7% and 32.7% were not aware of the radiation-free nature of MRI and USG, respectively. Respectively, 45.4% and 43.5% were of the misconception that Barium enema and Barium swallow studies do not involve radiation. Moreover, 77.6% and 87.9% were aware of the radiation-laden nature of CT and plain X-rays, respectively. Furthermore, 34% and 50%, respectively, think that they are not exposed to radiation at home and on a plane. Regarding the fatal cancer risk from CT, 17.8% chose the correct answer and 62% underestimated the risk. 32.2% correctly estimated the equivalent dose of CT in terms of number of conventional X-rays and 43.2% underestimated the dose. Most (98.2%) were told of the indication, and 42.7% were told the associated radiation dose. Conclusion Patient radiation awareness is unsatisfactory. There is need to increase patient radiation awareness, and to provide them with the necessary information.

We compared the parameters derived from diffusion-weighted imaging (DWI) and positron emission tomography/computed tomography (PET/CT) for treatment response evaluation and response prediction in patients with gastrointestinal stromal tumor (GIST). Seven patients with histologically proven metastatic disease were enrolled. DWI and PET/CT data were collected from all patients at diagnosis and from six at follow-up. All 37 lesions were identifiable in DWI with a sensitivity of 100%. To achieve higher accuracy, we used the apparent diffusion coefficient (ADC) of liver and background noise as thresholds for the measurement of the ADCs of lesions. Significant inverse correlations were found between ADCmean_thr (ADCmean with thresholds) and SUVmean (mean standardized uptake value) (R2 = 0.523, p

In this preliminary study, we aimed to investigate the abnormalities of water diffusion in children with temporal lobe epilepsy (TLE). Eight children with unilateral TLE (according to electroencephalography, EEG) and eight age- and sex-matched controls were recruited. Diffusion tensor imaging (DTI)/diffusional kurtosis imaging (DKI) acquisitions were performed. Radial diffusivity (λ⊥), axial diffusivity (λ∥), mean diffusivity (MD) and fractional anisotropy (FA) maps were calculated for both DTI and DKI, and radial kurtosis (K⊥), axial kurtosis (K∥) and mean kurtosis (MK) maps were calculated for DKI only. Mann–Whitney test showed that, for white matter in the temporal lobe, DKI-derived λ∥, MD and K∥ were significantly different in bilateral temporal lobes and EEG-abnormal and EEG-normal sides of the temporal lobe between patients and controls, whereas DTI showed no abnormalities. For gray matter, DKI detected significantly higher MD and MK in the same three comparisons, whereas DTI detected abnormalities only in the comparison between bilateral temporal lobes and between EEG-normal sides in cases and left–right matched sides in controls. No significant difference was observed between EEG-abnormal and EEG-normal sides in cases. These preliminary results indicate that DKI is more sensitive than DTI for the detection of diffusion abnormalities in the temporal lobes of children with TLE, even when EEG signals are normal. These findings pave the way for the application of DKI for in-depth studies on TLE in children. Copyright © 2012 John Wiley & Sons, Ltd.

Purpose: We investigated the incidence of lymph node metastasis in gastrointestinal stromal tumor (GIST) patients in our PET/CT database. The demographic data and characteristics of the primary tumor were evaluated in GIST patients with or without lymph node metastasis. Materials and Methods: We reviewed our PET/CT database from January 1, 2007 to November 30, 2010 by using keyword search, and identified GIST with lymph node metastasis according to our standard of reference. Statistical analysis was conducted between GIST group with or without lymph node metastasis based on the age, sex, primary tumor size, and primary tumor location. Results: A total of 29 GIST patients were found in our database. Six of them had lymph node metastasis, corresponding to 20.7%. When considering only the adult patients, the incidence was 17% (5 out of 28). There were 4 males and 1 female, with the mean age of 66.8 years old, which was 8 years older than the group without lymph node metastasis. Of the 5 adult metastasis patients, 4 had their primary tumor located at very rare sites other than stomach or small bowel. Statistical analysis using Fisher exact test of rare location showed significance between the 2 groups with P = 0.004. The mean size of the primary tumor in the group with lymph node metastasis was 5.2 cm, which was 2.9 cm less than the group without metastasis. No statistical significance was found in age, sex, or size of primary tumor between the 2 groups. Conclusion: The incidence of lymph node metastasis in GISTs in our database is 20.7%, which is surprisingly higher than we thought from other previous studies. In contrast to the group without lymph node metastasis, these patients tend to be of older ages and had rare location of the primary tumor. This result supports further study with larger sample size.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. It can be benign or malignant in behavior. Stomach, being the most common site (70%) for GISTs, is followed by the small intestine (20%). Anorectal, colonic, and esophageal GISTs are uncommon, whereas extraintestinal GISTs are extremely rare. The presenting symptoms are highly dependent on tumor size and location, although a large number of GISTs are asymptomatic. The purpose of this article is to highlight the unusual characteristics of GISTs illustrated by PET/CT and CT imaging. These characteristics are organized into (1) unusual tumor location, (2) unusual clinical presentation, and (3) unusual sites of metastasis. Knowing the uncommon features of GISTs is important, as they are more often seen nowadays with the increasingly important role of PET/CT and CT in GIST management; and these tumors are associated with a poorer prognosis and unwanted delay in diagnosis is avoidable. With the availability of effective treatment by imatinib mesylate, a prompt and early diagnosis is essential for disease control. All GISTs illustrated in this article are pathologically proven.

The melamine-tainted milk incident has caused renal disorders in more than 290,000 children from mainland China since the start of the outbreak in 2008. Since then, more than 27,000 children in Hong Kong have undergone renal US screening.To present and discuss the US features of melamine-related renal abnormalities in Hong Kong children.Between September 2008 and February 2009, 3,835 children attended the Department of Radiology of Princess Margaret Hospital for renal US examination. CT or plain abdominal radiography was performed in those with inconclusive findings. The US findings of detected melamine-related renal disorders were analysed.Echogenic foci in the kidneys were found in 22 children (0.6%). These were located in the renal pelvicalyceal system (in 12 children) and in the renal medulla (in 10 children). The echogenic foci measured 0.1-0.7 cm, with 6 children showing posterior acoustic shadowing, 14 showing comet-tail artefacts, and 2 showing echogenic dots.The incidence of renal disorders amongst Hong Kong children exposed to melamine was lower than in their mainland China counterparts. The renal stones detected were also relatively small, with most demonstrating comet-tail artefacts instead of posterior acoustic shadowing.

Background: Osteoarthritis of the hip is five to ten times more common in white people than in Chinese people. Little is known about the true prevalence of femoroacetabular impingement or its role in the development of osteoarthritis in the Chinese population. A cross-sectional study of both white and Chinese asymptomatic individuals was conducted to compare the prevalences of radiographic features posing a risk for femoroacetabular impingement in the two groups. It was hypothesized that that there would be proportional differences in hip anatomy between the white and Asian populations. Methods: Pelvic computed tomography scans of 201 subjects (ninety-nine white Belgians and 102 Chinese; 105 men and ninety-six women) without hip pain who were eighteen to forty years of age were assessed. The original axial images were reformatted to three-dimensional pelvic models simulating standardized radiographic views. Ten radiographic parameters predisposing to femoroacetabular impingement were measured: alpha angle, anterior offset ratio, and caput-collum-diaphyseal angle on the femoral side and crossover sign, ischial spine projection, acetabular anteversion angle, center-edge angle, acetabular angle of Sharp, Tonnis angle, and anterior acetabular head index on the acetabular side. Results: The white subjects had a less spherical femoral head than the Chinese subjects (average alpha angle, 56 degrees compared with 50 degrees; p < 0.001). The Chinese subjects had less lateral acetabular coverage than the white subjects, with average center-edge angles of 35 degrees and 39 degrees (p < 0.001) and acetabular angles of Sharp of 38 degrees and 36 degrees (p < 0.001), respectively. A shallower acetabular configuration was predominantly present in Chinese women. Conclusions: Significant differences in hip anatomy were demonstrated between young asymptomatic Chinese and white subjects. However, the absolute size of the observed differences appears to contrast with the reported low prevalence of femoroacetabular impingement in Chinese individuals compared with the high prevalence in white populations.

We report a young adult patient with known history of thalassaemia on regular blood transfusion presented with one month history of bilateral lower limbs paraesthesia, weakness and other neurological deficit. MRI scans show thoracic cord compression contributed by extramedullary hematopoiesis. Its clinical and radiological features are discussed.

Diffusion tensor imaging has already been extensively used to probe microstructural alterations in white matter tracts, and scarcely, in deep gray matter. However, results in literature regarding age-related degenerative mechanisms in white matter tracts and parametric changes in the putamen are inconsistent. Diffusional kurtosis imaging is a mathematical extension of diffusion tensor imaging, which could more comprehensively mirror microstructure, particularly in isotropic tissues such as gray matter. In this study, we used the diffusional kurtosis imaging method and a white-matter model that provided metrics of explicit neurobiological interpretations in healthy participants (58 in total, aged from 25 to 84 years). Tract-based whole-brain analyses and regions-of-interest (anterior and posterior limbs of the internal capsule, cerebral peduncle, fornix, genu and splenium of corpus callosum, globus pallidus, substantia nigra, red nucleus, putamen, caudate nucleus, and thalamus) analyses were performed to examine parametric differences across regions and correlations with age. In white matter tracts, evidence was found supportive for anterior-posterior gradient and not completely supportive for retrogenesis theory. Age-related degenerations appeared to be broadly driven by axonal loss. Demyelination may also be a major driving mechanism, although confined to the anterior brain. In terms of deep gray matter, higher mean kurtosis and fractional anisotropy in the globus pallidus, substantia nigra, and red nucleus reflected higher microstructural complexity and directionality compared with the putamen, caudate nucleus, and thalamus. In particular, the unique age-related positive correlations for fractional anisotropy, mean kurtosis, and radial kurtosis in the putamen opposite to those in other regions call for further investigation of exact underlying mechanisms. In summary, the results suggested that diffusional kurtosis can provide measurements in a new dimension that were complementary to diffusivity metrics. Kurtosis together with diffusivity can more comprehensively characterize microstructural compositions and age-related changes than diffusivity alone. Combined with proper model, it may also assist in providing neurobiological interpretations of the identified alterations.

[1] to compare 46 AD patients with 94 age-matched healthy volunteers (Australian Imaging Biomarkers & Lifestyle study). AFD is proportional to the image intensity, which is related to the quantity of intra-axonal water, and is therefore sensitive to the number of axons within a voxel (density). To perform voxel-wise comparisons of AFD, images were non-linearly warped to a common template image. We incorporated morphology information by modulating the AFD in each voxel based on the change to a fibre bundle’s cross-sectional area (atrophy). Modulation ensures the AFD in template space encapsulates both sources of axonal loss (axon density as measured by the MRI signal, and volume loss due to atrophy). We investigated whole-brain group AFD differences with and without modulation using novel tractography-based statistics. Results: Significant AFD decreases in AD were observed in white matter bundles known to be involved in language and memory (Fig.1). As shown in columns 1 & 2, the group AFD difference is more extensive when morphology information is included via AFDmodulation. Since AFD differences are associated with a voxel and direction (shown by the direction-colour-encoded tractogram in Fig.1) population differences can be attributed to a specific fibre bundle in regions with crossing-fibres (e.g. Arcuate Fasciculus).The absence of differences in fibre density (column 1) within regions previously detected using FA suggests that FA decreases detected in AD are largely caused by atrophy-induced partial volume changes. Conclusions: By incorporating morphology information, AFD is potentially a more sensitive and interpretable biomarker of axon degeneration compared to existing diffusion MRI measures based on image intensity alone.[1] Raffelt et al.2012,59(4):3976-94.

To improve the accuracy of volume and apparent diffusion coefficient (ADC) measurements in diffusion-weighted magnetic resonance imaging (MRI), we proposed a method based on thresholding both the b0 images and the ADC maps.In 21 heterogeneous lesions from patients with metastatic gastrointestinal stromal tumors (GIST), gross lesion were manually contoured, and corresponding volumes and ADCs were denoted as gross tumor volume (GTV) and gross ADC (ADC(g)), respectively. Using a k-means clustering algorithm, the probable high-cellularity tumor tissues were selected based on b0 images and ADC maps. ADC and volume of the tissues selected using the proposed method were denoted as thresholded ADC (ADC(thr)) and high-cellularity tumor volume (HCTV), respectively. The metabolic tumor volume (MTV) in positron emission tomography (PET)/computed tomography (CT) was measured using 40% maximum standard uptake value (SUV(max)) as the lower threshold, and corresponding mean SUV (SUV(mean)) was also measured.HCTV had excellent concordance with MTV according to Pearson's correlation (r=0.984, P.001) and linear regression (slope = 1.085, intercept = -4.731). In contrast, GTV overestimated the volume and differed significantly from MTV (P=.005). ADC(thr) correlated significantly and strongly with SUV(mean) (r=-0.807, P.001) and SUV(max) (r=-0.843, P.001); both were stronger than those of ADC(g).The proposed lesion-adaptive semiautomatic method can help segment high-cellularity tissues that match hypermetabolic tissues in PET/CT and enables more accurate volume and ADC delineation on diffusion-weighted MR images of GIST.

In the past 5 years, new ethylene copolymers have found their way into a wide variety of applications. The new polymers have a unique combination of properties not typically found in conventional elastomeric or thermoplastic ethylene polymers. The characterization of these polymers by new and improved analytical techniques is of great interest. We describe a thermal fractionation method which sorts the crystalline ethylene sequence lengths of the polymer into groups. The ethylene lengths are estimated using melting points of known hydrocarbons. Three statistical terms are introduced to describe ethylene sequence length distribution: the arithmetic mean L n , the weighted mean L w and the broadness index L w L n . We demonstrate the technique by comparing ethylene polymers produced with different catalyst systems, decipher ethylene components in unidentified ethylene blends and track changes in crystalline fractions with grafting.

To assess the awareness of radiation dose and associated risks caused by radiological procedures among local patients.All subjects were recruited by randomly sampling the patients receiving radiological examinations. These subjects were stratified on age, sex and education. The questionnaire was in Chinese and consisted of 28 questions mostly in multiple choice/true-or-false format, divided into three sections examining demographic data, radiation knowledge/awareness and expectations.A total of 173 questionnaires were returned (83 females and 84 females; mean age of 53). Of these, 32.6% had attended college, 32.6% had completed matriculation and 24.4% secondary school. Most subjects underwent CT (75), MRI (70) and PET-CT (18). Education significantly affected the radiation knowledge (P = 0.013). 60.7% and 32.7% were not aware of the radiation-free nature of MRI and USG, respectively. Respectively, 45.4% and 43.5% were of the misconception that Barium enema and Barium swallow studies do not involve radiation. Moreover, 77.6% and 87.9% were aware of the radiation-laden nature of CT and plain X-rays, respectively. Furthermore, 34% and 50%, respectively, think that they are not exposed to radiation at home and on a plane. Regarding the fatal cancer risk from CT, 17.8% chose the correct answer and 62% underestimated the risk. 32.2% correctly estimated the equivalent dose of CT in terms of number of conventional X-rays and 43.2% underestimated the dose. Most (98.2%) were told of the indication, and 42.7% were told the associated radiation dose.Patient radiation awareness is unsatisfactory. There is need to increase patient radiation awareness, and to provide them with the necessary information.

We compared the parameters derived from diffusion-weighted imaging (DWI) and positron emission tomography/computed tomography (PET/CT) for treatment response evaluation and response prediction in patients with gastrointestinal stromal tumor (GIST). Seven patients with histologically proven metastatic disease were enrolled. DWI and PET/CT data were collected from all patients at diagnosis and from six at follow-up. All 37 lesions were identifiable in DWI with a sensitivity of 100%. To achieve higher accuracy, we used the apparent diffusion coefficient (ADC) of liver and background noise as thresholds for the measurement of the ADCs of lesions. Significant inverse correlations were found between ADC(mean_thr) (ADC(mean) with thresholds) and SUV(mean) (mean standardized uptake value) (R(2)=0.523, p0.001 at diagnosis, and R(2)=0.916, p0.001 at follow-up), between ADC(mean_thr) and SUV(max) (maximum SUV) (R(2)=0.529, p0.001 at diagnosis, and R(2)=0.761, p0.001 at follow-up), between ΔADC(mean_thr) (percentage change in ADC(mean_thr) ) and ΔSUV(mean) (percentage change in SUV(mean) ) (R(2)=0.384, p0.001), and between ΔADC(mean_thr) and ΔSUV(max) (percentage change in SUV(max) ) (R(2)=0.500, p0.001). In lesion-based analysis, pre-treatment ADC(mean_thr) outperformed SUV(mean) and SUV(max) in treatment response prediction, with an area under the receiver operating characteristic curve of 0.706. These results show that DWI can provide a quantitative assessment comparable with PET/CT in GIST lesion characterization, treatment response evaluation and response prediction.

With the evolution of immunochemical staining techniques and better imaging modalities with better image resolution and whole body coverage, gastrointestinal stromal tumor (GIST), the most common mesenchymal tumor of the gastrointestinal tract, is often encountered in clinical practice. Metastasis is common with malignant GIST and can be found in up to 50% of patients at presentation. Liver and peritoneum are the two most common sites of metastasis and accounted for 95% of cases. Lymphatics, bone and lung metastasis are rare. Malignant GIST with intracranial metastasis is even rarer, with only a few cases reported in the literature, and most of these had earlier metastasis elsewhere. Radiological features for GISTs are not specific but it does contribute to confirming early and accurate diagnosis of malignant GISTs by judging the tumor size, enhancement pattern and the invasion of adjacent structures. We report a case of a 26-year-old male with metastatic GIST to the liver and subsequently to the brain and skull vault. This is the first case reported in our locality and he is the youngest patient reported with this disease entity. The clinical progress, radiological features and the role of imaging will be discussed further in this paper. The radiological and clinical features of the primary tumor will specifically be addressed. The purpose of this paper is to enrich the current database of this rare disease entity and to alert both radiologists and clinicians about the imaging features of GIST with intracranial metastasis.

Objectives To investigate the optimal PET protocol and analytical method to characterize the glucose metabolism in nasopharyngeal carcinoma (NPC). Methods Newly diagnosed NPC patients were recruited and a dynamic PET-CT scan was performed. The optimized threshold to derive the arterial input function (AIF) was studied. Two-tissue compartmental kinetic modeling using three, four, and five parameters, Patlak graphical analysis, and time sensitivity (S-factor) analysis were performed. The best compartmental model was determined in terms of goodness of fit, and correlated with Ki from Patlak graphical analysis and the S-factor. The methods with R>0.9 and P

In this preliminary study, we aimed to investigate the abnormalities of water diffusion in children with temporal lobe epilepsy (TLE). Eight children with unilateral TLE (according to electroencephalography, EEG) and eight age- and sex-matched controls were recruited. Diffusion tensor imaging (DTI)/diffusional kurtosis imaging (DKI) acquisitions were performed. Radial diffusivity (λ(⊥)), axial diffusivity (λ(∥)), mean diffusivity (MD) and fractional anisotropy (FA) maps were calculated for both DTI and DKI, and radial kurtosis (K(⊥)), axial kurtosis (K(∥)) and mean kurtosis (MK) maps were calculated for DKI only. Mann-Whitney test showed that, for white matter in the temporal lobe, DKI-derived λ(∥) , MD and K(∥) were significantly different in bilateral temporal lobes and EEG-abnormal and EEG-normal sides of the temporal lobe between patients and controls, whereas DTI showed no abnormalities. For gray matter, DKI detected significantly higher MD and MK in the same three comparisons, whereas DTI detected abnormalities only in the comparison between bilateral temporal lobes and between EEG-normal sides in cases and left-right matched sides in controls. No significant difference was observed between EEG-abnormal and EEG-normal sides in cases. These preliminary results indicate that DKI is more sensitive than DTI for the detection of diffusion abnormalities in the temporal lobes of children with TLE, even when EEG signals are normal. These findings pave the way for the application of DKI for in-depth studies on TLE in children.

Purpose We investigated the correlation relationship between ADCs measured by MRI and SUVs measured by PET/CT of lesions on GIST (gastrointestinal stromal tumor) patients to verify if MR is able to replace or serve as an alternative to PET/CT in GIST staging and treatment monitoring. Materials and methods Between September 2010 and January 2011, five patients with histologically proven metastatic GIST in Queen Mary Hospital, Hong Kong were enrolled into our study. All patients underwent both MRI and PET/CT scans at prognosis. Pearson's correlations of twenty-nine lesions were conducted between 5 pairs of ADCs and SUVs values. Results Lesions in the liver, peritoneum or bowel loops were found by PET/CT and no extra-abdominal lesion was identified. All twenty-nine lesions are identifiable by MRI with sensitivity of 100%. Significant inverse correlation were found between ADC mean and SUV mean ( P = 0.006), ADC mean and SUV max ( P = 0.010), ADC min and SUV max ( P = 0.014), ADC min and SUV mean ( P = 0.026), rADC min and rSUV max ( P = 0.047). Conclusion DWI is comparable to PET/CT in visually detecting the GIST lesions’ location. Significant inverse correlations were found between ADCs from DWIBS and SUVs from PET/CT on data of GIST patients. This finding demonstrates that DWI is potentially capable of offering similar information for diagnosis and treatment response evaluating in GIST's patients as PET/CT does. Furthermore, ADC min , which is determined by single pixel, is not as reliable as ADC mean , which is weighted average value of the whole lesion volume.

Haepatocellular carcinoma (HCC) is the most common primary liver malignancy, representing the fifth most common cancer in the world. Without treatment, the median survival of HCC patients has been reported to be 8 weeks from symptomatic presentation. Transarterial chemoembolisation is widely used to manage unresectable HCCs. However, when a tumour is large or locates near the liver capsule, it may receive supplies from vessels other than hepatic arteries. In this paper, we discuss the anatomy of possible extrahepatic collateral arterial supplies of HCCs.

The reactivities of RhCI(PPh3)3, RhCl(PPh3)2, and Rh2Cl2(PPh3)4 toward H2, and the contributions of each of these species to the overall rate of hydrogenation of RhCl(PPh3)3 in solution, have been determined; RhCl(PPh3)2 is at least 104 times as reactive as the other two species.

The preparation of Rh2(OAc)2(dmg)2(PPh3)2 and the determination of its structure by single crystal X-ray diffraction are described; the Rh–Rh bond length is 2·618(5)A.