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2.
AJNR Am J Neuroradiol ; 44(2): 125-133, 2023 02.
Article in English | MEDLINE | ID: mdl-36702502

ABSTRACT

BACKGROUND AND PURPOSE: A scout accelerated motion estimation and reduction (SAMER) framework has been developed for efficient retrospective motion correction. The goal of this study was to perform an initial evaluation of SAMER in a series of clinical brain MR imaging examinations. MATERIALS AND METHODS: Ninety-seven patients who underwent MR imaging in the inpatient and emergency department settings were included in the study. SAMER motion correction was retrospectively applied to an accelerated T1-weighted MPRAGE sequence that was included in brain MR imaging examinations performed with and without contrast. Two blinded neuroradiologists graded images with and without SAMER motion correction on a 5-tier motion severity scale (none = 1, minimal = 2, mild = 3, moderate = 4, severe = 5). RESULTS: The median SAMER reconstruction time was 1 minute 47 seconds. SAMER motion correction significantly improved overall motion grades across all examinations (P < .005). Motion artifacts were reduced in 28% of cases, unchanged in 64% of cases, and increased in 8% of cases. SAMER improved motion grades in 100% of moderate motion cases and 75% of severe motion cases. Sixty-nine percent of nondiagnostic motion cases (grades 4 and 5) were considered diagnostic after SAMER motion correction. For cases with minimal or no motion, SAMER had negligible impact on the overall motion grade. For cases with mild, moderate, and severe motion, SAMER improved the motion grade by an average of 0.3 (SD, 0.5), 1.1 (SD, 0.3), and 1.1 (SD, 0.8) grades, respectively. CONCLUSIONS: SAMER improved the diagnostic image quality of clinical brain MR imaging examinations with motion artifacts. The improvement was most pronounced for cases with moderate or severe motion.


Subject(s)
Inpatients , Magnetic Resonance Imaging , Humans , Retrospective Studies , Magnetic Resonance Imaging/methods , Imaging, Three-Dimensional/methods , Motion , Artifacts , Image Processing, Computer-Assisted/methods
4.
AJNR Am J Neuroradiol ; 42(9): 1584-1590, 2021 09.
Article in English | MEDLINE | ID: mdl-34244127

ABSTRACT

BACKGROUND AND PURPOSE: Our aim was to evaluate an ultrafast 3D-FLAIR sequence using Wave-controlled aliasing in parallel imaging encoding (Wave-FLAIR) compared with standard 3D-FLAIR in the visualization and volumetric estimation of cerebral white matter lesions in a clinical setting. MATERIALS AND METHODS: Forty-two consecutive patients underwent 3T brain MR imaging, including standard 3D-FLAIR (acceleration factor = 2, scan time = 7 minutes 50 seconds) and resolution-matched ultrafast Wave-FLAIR sequences (acceleration factor = 6, scan time = 2 minutes 45 seconds for the 20-channel coil; acceleration factor = 9, scan time = 1 minute 50 seconds for the 32-channel coil) as part of clinical evaluation for demyelinating disease. Automated segmentation of cerebral white matter lesions was performed using the Lesion Segmentation Tool in SPM. Student t tests, intraclass correlation coefficients, relative lesion volume difference, and Dice similarity coefficients were used to compare volumetric measurements among sequences. Two blinded neuroradiologists evaluated the visualization of white matter lesions, artifacts, and overall diagnostic quality using a predefined 5-point scale. RESULTS: Standard and Wave-FLAIR sequences showed excellent agreement of lesion volumes with an intraclass correlation coefficient of 0.99 and mean Dice similarity coefficient of 0.97 (SD, 0.05) (range, 0.84-0.99). Wave-FLAIR was noninferior to standard FLAIR for visualization of lesions and motion. The diagnostic quality for Wave-FLAIR was slightly greater than for standard FLAIR for infratentorial lesions (P < .001), and there were fewer pulsation artifacts on Wave-FLAIR compared with standard FLAIR (P < .001). CONCLUSIONS: Ultrafast Wave-FLAIR provides superior visualization of infratentorial lesions while preserving overall diagnostic quality and yields white matter lesion volumes comparable with those estimated using standard FLAIR. The availability of ultrafast Wave-FLAIR may facilitate the greater use of 3D-FLAIR sequences in the evaluation of patients with suspected demyelinating disease.


Subject(s)
Brain , White Matter , Artifacts , Brain/diagnostic imaging , Brain/pathology , Humans , Magnetic Resonance Imaging , Motion , White Matter/diagnostic imaging , White Matter/pathology
6.
Clin Otolaryngol ; 43(2): 463-469, 2018 04.
Article in English | MEDLINE | ID: mdl-28950051

ABSTRACT

OBJECTIVES: Nasopharyngeal cancer (NPC) is an endemic disease in Taiwan. Prognostic factors the anatomical TNM stage are important for its prognostic stratification. An elevated neutrophil-to-lymphocyte ratio (NLR) has been reported to be associated with poor prognosis in various solid tumours. In this study, we analysed the prognostic impact of the NLR in NPC in Taiwan. DESIGN: Single-institution retrospective study. SETTING: Medical centre. PARTICIPANTS: One hundred and eighty patients with NPC treated at the Far Eastern Memorial Hospital, Taiwan, from January 2007 to December 2013. MAIN OUTCOME MEASURES: The association between the clinical or haematological presentations and the prognosis. RESULTS: The majority of the 180 patients included in this study were men (80%) and were <65 years old (91.7%). A neck mass (55.6%) was the most common clinical presentation, followed by nasal (39.4%) and aural (30.6%) symptoms. In addition, the majority (75.4%) of patients had advanced stage (III and IV) disease. Patients with a high NLR (≧3.6) had significantly lower progression-free survival, overall survival and disease-specific survival rates. The association between high NLR and poor prognosis was more pronounced in patients with advanced disease than in those with early-stage NPC. The results of a multivariate analysis revealed that advanced age, clinical symptoms including headache, diplopia and facial numbness, advanced disease stage, and high NLR were independent prognostic factors. CONCLUSION: A high NLR is an independent poor prognostic factor of NPC in Taiwan.


Subject(s)
Asian People , Lymphocyte Count , Nasopharyngeal Carcinoma/blood , Nasopharyngeal Carcinoma/mortality , Nasopharyngeal Neoplasms/blood , Nasopharyngeal Neoplasms/mortality , Neutrophils , Adult , Aged , Disease-Free Survival , Female , Humans , Male , Middle Aged , Nasopharyngeal Carcinoma/diagnosis , Nasopharyngeal Neoplasms/diagnosis , Prognosis , Retrospective Studies , Survival Rate , Taiwan , Young Adult
7.
Clin Otolaryngol ; 43(2): 477-482, 2018 04.
Article in English | MEDLINE | ID: mdl-28981204

ABSTRACT

OBJECTIVE: To establish a real-time predictive scoring model based on sonographic characteristics for identifying malignant cervical lymph nodes (LNs) in cancer patients after neck irradiation. METHODS: One-hundred forty-four irradiation-treated patients underwent ultrasonography and ultrasound-guided fine-needle aspirations (USgFNAs), and the resultant data were used to construct a real-time and computerised predictive scoring model. This scoring system was further compared with our previously proposed prediction model. RESULTS: A predictive scoring model, 1.35 × (L axis) + 2.03 × (S axis) + 2.27 × (margin) + 1.48 × (echogenic hilum) + 3.7, was generated by stepwise multivariate logistic regression analysis. Neck LNs were considered to be malignant when the score was ≥ 7, corresponding to a sensitivity of 85.5%, specificity of 79.4%, positive predictive value (PPV) of 82.3%, negative predictive value (NPV) of 83.1%, and overall accuracy of 82.6%. When this new model and the original model were compared, the areas under the receiver operating characteristic curve (c-statistic) were 0.89 and 0.81, respectively (P < .05). CONCLUSIONS: A real-time sonographic predictive scoring model was constructed to provide prompt and reliable guidance for USgFNA biopsies to manage cervical LNs after neck irradiation.


Subject(s)
Head and Neck Neoplasms/diagnostic imaging , Head and Neck Neoplasms/secondary , Lymph Nodes/pathology , Lymphatic Metastasis/diagnosis , Adult , Aged , Biopsy, Fine-Needle , Female , Head and Neck Neoplasms/radiotherapy , Humans , Logistic Models , Lymph Nodes/diagnostic imaging , Male , Middle Aged , Predictive Value of Tests , ROC Curve , Ultrasonography
8.
Clin Otolaryngol ; 43(1): 124-130, 2018 02.
Article in English | MEDLINE | ID: mdl-28556524

ABSTRACT

OBJECTIVE: Office-based laryngeal procedures (OBLPs) are emerging as effective alternative modalities for vocal disorders. This study systematically investigates the haemodynamic status of patients, specifically focusing on the potential effects of underlying comorbidity and medication use. DESIGN: Prospective cohort study. SETTING: Tertiary referral centre. PARTICIPANTS: We prospectively recruited 214 consecutive patients who received OBLPs during January-December 2015. All procedures were performed under local anaesthesia without sedation, in an upright (sitting) position. MAIN OUTCOME MEASURES: We measured heart rate (HR), systolic and diastolic blood pressure, and oxygen saturations at baseline (before procedure), immediately after local anaesthesia to the pharynx and larynx, immediately after completing of procedure, and 20 minutes after the procedure. RESULTS: Systolic, diastolic blood pressures and HR all significantly increased after local anaesthesia, and gradually decreased after the procedure (P<.01). Oxygen concentration remained unchanged. Patients with comorbidity and those receiving vasoactive medications showed significantly higher perioperative blood pressures than the other patients (P<.05), but the trend remained similar. Prominent hypertension (systolic ≥160 mm Hg or diastolic ≥100 mm Hg) was noted in 17 patients, more commonly in patients with older age, higher baseline blood pressures and receiving vasoactive medications. Only 2% of patients with normal baseline measurements developed prominent hypertension perioperatively. Tachycardia (HR≥100 bpm) developed in 22 patients, more frequently in patients with higher baseline HRs, and perceiving greater discomforts. CONCLUSION: This study revealed that routine haemodynamic monitoring may not be necessary for all the OBLPs, but should be considered for older patients, those with higher baseline blood pressure or HR, sensitive patients who might be more susceptible to perioperative discomfort, and those receiving vasoactive medications.


Subject(s)
Antihypertensive Agents/therapeutic use , Hemodynamics/physiology , Hypertension/epidemiology , Laryngeal Diseases/epidemiology , Laryngoscopy , Adult , Aged , Aged, 80 and over , Comorbidity/trends , Female , Follow-Up Studies , Humans , Hypertension/drug therapy , Hypertension/physiopathology , Laryngeal Diseases/therapy , Male , Middle Aged , Prospective Studies , Taiwan/epidemiology , Young Adult
9.
Hong Kong Med J ; 23(5): 454-61, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28416733

ABSTRACT

INTRODUCTION: In all cases of suspected child abuse, accurate risk assessment is vital to guide further management. This study examined the relationship between risk factors in a risk assessment matrix and child abuse case conference outcomes. METHODS: Records of all children hospitalised at United Christian Hospital in Hong Kong for suspected child abuse from January 2012 to December 2014 were reviewed. Outcomes of the hospital abuse work-up as concluded in the Multi-Disciplinary Case Conference were categorised as 'established', 'high risk', or 'not established'. All cases of 'established' and 'high risk' were included in the positive case conference outcome group and all cases of 'not established' formed the comparison group. On the other hand, using the Risk Assessment Matrix developed by the California State University, Fresno in 1990, each case was allotted a matrix score of low, intermediate, or high risk in each of 15 matrix domains, and an aggregate matrix score was derived. The effect of individual matrix domain on case conference outcome was analysed. Receiver operating characteristic curve analysis was used to examine the relationship between case conference outcome and aggregate matrix score. RESULTS: In this study, 265 children suspected of being abused were included, with 198 in the positive case conference outcome group and 67 in the comparison group. Three matrix domains (severity and frequency of abuse, location of injuries, and strength of family support systems) were significantly associated with case conference outcome. An aggregate cut-off score of 23 yielded a sensitivity of 91.4% and specificity of 38.2% in relation to outcome of abuse categorisation. CONCLUSIONS: Risk assessment should be performed when handling suspected child abuse cases. A high aggregate score should arouse suspicion in all disciplines managing child abuse cases.


Subject(s)
Child Abuse/statistics & numerical data , Patient Care Team , Risk Assessment , Teaching Rounds , Benchmarking , Case-Control Studies , Child , Child Abuse/prevention & control , Child Health Services/standards , Delivery of Health Care, Integrated/standards , Female , Hong Kong/epidemiology , Humans , Male , ROC Curve , Retrospective Studies , Risk Factors
11.
Neuroscience ; 254: 222-9, 2013 Dec 19.
Article in English | MEDLINE | ID: mdl-24060824

ABSTRACT

The purpose of this study was to examine the dose-response effectiveness of d-methionine (d-met) in rescuing a noise-induced permanent threshold shift (PTS) and cochlear biochemistry following noise exposure. One hour after being exposed to continuous broadband white noise at 105dB sound pressure level (SPL) for 6h, guinea-pigs were treated five times at 12-h intervals with 200, 400, or 600mg/kg d-met or sterile 0.9% saline (each group, N=6) by intraperitoneal injection. Six guinea-pigs with normal hearing that were not exposed to noise served as control animals. Although administration of d-met 200mg/kg did not significantly reduce the mean PTS, treatment with d-met 600mg/kg achieved a complete rescue response. The level of rescue from noise-induced PTS following treatment with 200, 400, or 600mg/kg d-met was dose dependent. The attenuation of the noise-induced decreases in the activities of the Na(+), K(+)-ATPase and Ca(2+)-ATPase following treatment with 200, 400, or 600mg/kg d-met was also dose dependent. Likewise, d-met-dose-dependent decreases in mean lipid peroxidation and nitric oxide levels were observed in the d-met treated groups. Significant attenuation of increased oxidative stress and decreased ATPase activities was concurrent with the d-met-mediated improvements in noise-induced auditory dysfunction.


Subject(s)
Auditory Threshold/drug effects , Auditory Threshold/physiology , Evoked Potentials, Auditory, Brain Stem/drug effects , Evoked Potentials, Auditory, Brain Stem/physiology , Methionine/pharmacology , Noise/adverse effects , Animals , Dose-Response Relationship, Drug , Guinea Pigs , Random Allocation
14.
Environ Pollut ; 165: 1-10, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22390975

ABSTRACT

As the consumption of electricity increases, air pollutants from power generation increase. In metropolitans such as Hong Kong and other Asian cities, the surge of electricity consumption has been phenomenal over the past decades. This paper presents a historical review about electricity consumption, population, and change in economic structure in Hong Kong. It is hypothesized that the growth of electricity consumption and change in gross domestic product can be modeled by 4-parameter logistic functions. The accuracy of the functions was assessed by Pearson's correlation coefficient, mean absolute percent error, and root mean squared percent error. The paper also applies the life cycle approach to determine carbon dioxide, methane, nitrous oxide, sulfur dioxide, and nitrogen oxide emissions for the electricity consumption of Hong Kong. Monte Carlo simulations were applied to determine the confidence intervals of pollutant emissions. The implications of importing more nuclear power are discussed.


Subject(s)
Electricity , Fossil Fuels/statistics & numerical data , Population Growth , Air Pollution/statistics & numerical data , Environmental Monitoring , Humans
15.
Energy (Oxf) ; 36(2): 1134-1142, 2011 Feb.
Article in English | MEDLINE | ID: mdl-32288043

ABSTRACT

A number of Asian cities decided to establish gaming and resort facilities in order to capitalize on the growing number of gamblers and their family members in Asia. In doing so, they expect to sustain economic growth but, on the other hand, will consume a considerable amount of energy. Nevertheless, the causal relationship between economic growth and electricity consumption in this type of service-oriented territories has never been investigated. Using the historical data obtained from the Government of Macao SAR, we found that electricity consumption and economic growth in terms of gross domestic product are co-integrated for the period of 1999 Quarter 1-2008 Quarter 4. Moreover, vector error correction (VEC) models indicated a lack of short-run relationships but showed that there was a long-run equilibrium relationship between electricity consumption and gross domestic product. The accuracy of VEC models was assessed by using the mean squared error and the mean absolute error. The error analysis shows that VEC models reproduced time series of gross domestic product and electricity consumption in difference form accurately.

16.
Neuroscience ; 159(2): 727-34, 2009 Mar 17.
Article in English | MEDLINE | ID: mdl-19167463

ABSTRACT

Neuronal nitric oxide synthases (nNOS) is distributed throughout the central nervous system (CNS) and has been proposed to modulate neuronal activity in the nucleus tractus solitarii (NTS). Here, we investigated whether the activation of nNOS is involved in insulin-induced cardiovascular responses in the NTS. Insulin (100 IU/ml) was unilaterally microinjected into the NTS, and the cardiovascular effects were evaluated before and after microinjection of the nNOS inhibitors 7-nitroindazole (7-NI) (5 pmol) and N(5)-(1-imino-3-butenyl)-l-ornithine (vinyl-L-NIO) (600 pmol). Western blot and immunohistochemical analyses were performed to determine nNOS phosphorylation levels after insulin or phosphoinositide 3-kinase (PI3K) inhibitor LY294002 microinjection into the NTS. Unilateral microinjection of insulin into the NTS produced prominent depressor and bradycardic effects in WKY rats. Pretreatment with the nNOS inhibitors 7-NI and Vinyl-L-NIO attenuated the cardiovascular response evoked by insulin in Wistar-Kyoto (WKY) rats. Moreover, Western blot analysis showed a significant increase in nNOS (16.5+/-0.4-fold; P<0.05; n=4) phosphorylation after insulin injection, whereas the PI3K inhibitor LY294002 abolished the insulin-induced effects. In situ nNOS phosphorylation was found to be increased in the NTS after insulin injection. Furthermore, co-immunoprecipitation assay showed Akt and nNOS can bind to each other as detected by phospho-Akt(S473) and phospho-nNOS(S1416) antibodies. In vitro kinase assay showed insulin activated Akt can directly phosphorylate nNOS(S1416). These results demonstrated that nNOS may couple with the activation of the insulin receptor, via the liberation of NO, in order to participate in central cardiovascular regulation of WKY rats.


Subject(s)
Blood Pressure/drug effects , Heart Rate/drug effects , Insulin/pharmacology , Nitric Oxide Synthase Type I/metabolism , Solitary Nucleus/drug effects , Analysis of Variance , Animals , Chromones/pharmacology , Dose-Response Relationship, Drug , Drug Interactions , Enzyme Activation/drug effects , Enzyme Inhibitors/pharmacology , Gene Expression Regulation, Enzymologic/drug effects , Heart Rate/radiation effects , Immunoprecipitation/methods , Indazoles/pharmacology , Male , Microinjections/methods , Morpholines/pharmacology , Ornithine/analogs & derivatives , Ornithine/pharmacology , Rats , Rats, Inbred WKY , Solitary Nucleus/enzymology
17.
J Laryngol Otol ; 123(9): 1055-7, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19046468

ABSTRACT

OBJECTIVE: We report an extremely rare case of Langerhans' cell histiocytosis involving isolated cervical lymph nodes, and we discuss the diagnosis and treatment of this infrequent disease. METHOD: We present a case report and literature review concerning this disease entity. RESULTS: A 54-year-old man presented with persistent, multiple, left neck masses. Histopathological study of lymph node specimens showed proliferation of Langerhans' cells coupled with eosinophilic and neutrophilic microabscesses. Positive immunohistochemical staining for Cluster of Differentiation 1a (CD1a) in Langerhans' cells confirmed the diagnosis. No other abnormalities were noted on a series of image studies. The patient was managed with 'watchful waiting' without subsequent therapy. The neck lesions regressed gradually over time, and the patient did well over a two-year follow-up period. CONCLUSION: The clinical presentation of Langerhans' cell histiocytosis is highly variable, and the choice of treatment depends on the involved organs. Definitive diagnosis depends on identification of characteristic immunohistochemical or ultrastructural features of the biopsy specimen. Watchful waiting may be an effective management strategy in cases of adult isolated lymph node Langerhans' cell histiocytosis, due to its possible spontaneous regression.


Subject(s)
Histiocytosis, Langerhans-Cell/pathology , Lymph Nodes/pathology , Biopsy , Humans , Male , Middle Aged , Neck , Remission, Spontaneous , Tomography, X-Ray Computed
19.
J Biomed Sci ; 8(5): 389-94, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11549880

ABSTRACT

Adenosine was shown to inhibit norepinephrine (NE) release from sympathetic nerve endings. The purpose of this study was to examine whether endogenous adenosine restrains NE and epinephrine release from the adrenal medulla. The effects of an adenosine receptor antagonist, 1,3-dipropyl-8-(p-sulfophenyl) xanthine (DPSPX), on epinephrine and NE release induced by intravenous administration of insulin in conscious rats were examined. Plasma catecholamines were measured by HPLC with an electrochemical detector. DPSPX significantly increased plasma catecholamine in both control rats and rats treated with insulin. The effect of DPSPX on plasma catecholamine was significantly greater in rats treated with insulin. Additional experiments were performed in adrenalectomized rats to investigate the contribution of the adrenal medulla to the effect of DPSPX on plasma catecholamine. The effect of DPSPX and insulin on epinephrine in adrenalectomized rats was significantly reduced compared with that of the controls. Finally, we tested whether endogenous adenosine restrains catecholamine secretion partially through inhibiting the renin-angiotensin system. The effect of DPSPX on plasma catecholamine in rats pretreated with captopril (an angiotensin-converting enzyme inhibitor) was reduced. These results demonstrate that under basal physiological conditions, endogenous adenosine tonically inhibits catecholamine secretion from the adrenal medulla, and this effect is augmented when the sympathetic system is stimulated. The effect of endogenous adenosine on catecholamine secretion from the adrenal medulla is achieved partially through the inhibitory effect of adenosine on the renin-angiotensin system.


Subject(s)
Adenosine/metabolism , Adrenal Medulla/metabolism , Catecholamines/metabolism , Adrenal Medulla/drug effects , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , Antihypertensive Agents/pharmacology , Blood Pressure/drug effects , Captopril/pharmacology , Epinephrine/blood , Injections, Intravenous , Insulin/pharmacology , Male , Norepinephrine/blood , Purinergic P1 Receptor Antagonists , Rats , Rats, Sprague-Dawley , Xanthines/pharmacology
20.
J Microbiol Immunol Infect ; 34(2): 147-9, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11456362

ABSTRACT

Virus-associated hemophagocytic syndrome (VAHS) is a non-neoplastic, generalized histiocytic proliferation with prominent hemophagocytosis associated with a systemic viral infection. Although Epstein-Barr virus (EBV) is one candidate virus for this association, thorough serologic and molecular biologic studies to determine the presence of the viral infection have been lacking in many reports. Whereas elevated liver function tests are common findings in patients with VAHS, exudative ascites and abdominal lymphadenopathy are rare. We describe a case of EBV-AHS masquerading as lymphoma in which treatment with intravenous immunoglobulins was associated with complete clinical remission at 2 years and 6 months after the onset. Regardless of the exact mechanism responsible for ascites formation in VAHS, this case adds support to the possible involvement of EBV in patients with abdominal lymphadenopathy and ascites.


Subject(s)
Epstein-Barr Virus Infections/diagnosis , Histiocytosis, Non-Langerhans-Cell/diagnosis , Lymphoma/diagnosis , Child, Preschool , Diagnosis, Differential , Female , Humans
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