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Síndrome Coronario Agudo/diagnóstico , Dolor en el Pecho/etiología , Índice de Severidad de la Enfermedad , Troponina T/sangre , Dolor en el Pecho/diagnóstico , Electrocardiografía , Servicio de Urgencia en Hospital , Femenino , Humanos , Modelos Logísticos , Masculino , Análisis Multivariante , Estudios Prospectivos , Medición de Riesgo , Factores de RiesgoRESUMEN
BACKGROUND: Chest pain patients commonly present to emergency departments (ED), and require either hospital admission and/or lengthy diagnostic protocols to rule-out myocardial infarction. We aimed to identify the best combination of add-on tests to high-sensitivity cardiac troponin (hs-cTnT) for predicting 30-day major adverse cardiac events (MACE) in adult chest pain patients presenting to an ED with suspected acute coronary syndrome. METHODS: This prospective observational study was conducted in the ED of a tertiary university hospital in Hong Kong, recruiting adult patients with chest pain of less than 24h duration, suspected with acute coronary syndrome (ACS), and had no history of coronary artery bypass grafting or stent insertion. Patients underwent triage assessment, electrocardiography, blood sampling for laboratory hs-cTnT, and Thrombolysis in Myocardial Infarction (TIMI) and HEART score assessment. The primary outcome was the number of patients with 30-day MACE. RESULTS: 602 consecutive patients were recruited and completed 30-day follow-up. A 30-day MACE occurred in 42 (7.0%) patients. Out of 12 possible models for stratifying patients at risk of 30-day MACE within 2h of ED arrival, a combination of electrocardiography (ECG) and one-time hs-cTnT (model 5) provided the simplest and most accurate model. A risk score of 0 to 5 was derived from raw coefficients of model 5. The risk score provided excellent calibration (P=0.91) and discrimination (AUC 0.87, 95% CI: 0.82 to 0.93). CONCLUSION: Appropriate early risk-stratification of patients with chest pain and possible ACS using a combination of ECG and one-time hs-cTnT may improve efficiency of care.
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Dolor en el Pecho , Medición de Riesgo/métodos , Síndrome Coronario Agudo/diagnóstico , Síndrome Coronario Agudo/epidemiología , Anciano , Dolor en el Pecho/diagnóstico , Dolor en el Pecho/epidemiología , Diagnóstico Diferencial , Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/estadística & datos numéricos , Electrocardiografía/métodos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Femenino , Hong Kong/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/epidemiología , Proyectos de Investigación , Factores de Tiempo , Triaje/métodosRESUMEN
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.
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Carcinoma/diagnóstico por imagen , Carcinoma/cirugía , Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias Nasofaríngeas/diagnóstico por imagen , Neoplasias Nasofaríngeas/cirugía , Adulto , Factores de Edad , Anciano , Determinación de Punto Final , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Valor Predictivo de las Pruebas , Insuficiencia del Tratamiento , Resultado del TratamientoRESUMEN
OBJECTIVES: To investigate the influence of variations in resting pressure (precompression) on thyroid ultrasound supersonic shear wave elastography (SWE). METHODS: Thirty-five normal thyroid glands (Norm), 55 benign hyperplastic nodules (BHN), and 17 papillary thyroid cancers (PTC) in 96 subjects underwent thyroid SWE. Four precompression levels were applied manually by the operator, ranging from A (baseline, 0 % strain) to D (high, 22-30 % strain). SWE results at each precompression level were compared using ANOVA tests with P < 0.05 indicating significance. RESULTS: SWE indices were highest in PTC, followed by BHN and Norm at each precompression level (P < 0.05). All tissue types showed successive increases in SWE results as precompression increased, although the rate was higher for PTC than BHN and Norm (Ps < 0.05). SWE values (kPa) of Norm, BHN, and PTC at baseline precompression (A) were 10.3 ± 3.3, 17.7 ± 7.6, and 22.2 ± 11.9 compared with 21.1 ± 4.2, 42.3 ± 16.0, and 97.6 ± 46.8 at high precompression (D). SWE index differences between precompression levels A and D were 10.8 kPa for Norm, 24.6 kPa for BHN, and 75.4 kPa for PTC. CONCLUSION: PTCs show greater SWE stiffening than BHN as precompression rises. Precompression effects on thyroid nodules are not negligible and may account for wide discrepancies in published SWE discriminatory performance results for thyroid malignancy. KEY POINTS: ⢠Increases in resting pressure (precompression) applied by the operator increases thyroid stiffness. ⢠Papillary cancers show greater increases in stiffness (strain hardening) than benign nodules. ⢠Precompression may affect the diagnostic performance of shearwave elastography for thyroid malignancy.
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Diagnóstico por Imagen de Elasticidad/métodos , Nódulo Tiroideo/diagnóstico , Ultrasonografía/métodos , Adulto , Carcinoma/diagnóstico , Carcinoma Papilar , Elasticidad , Femenino , Humanos , Masculino , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/diagnósticoRESUMEN
PURPOSE: Ultrasound is a well-established imaging modality in the assessment of malignant cervical lymphadenopathy. With the use of Doppler ultrasound, intranodal vascularity can be evaluated. However, the major limitation of ultrasound is operator dependency. Therefore, this study aimed to evaluate and compare the diagnostic accuracy and reliability of the subjective grading and computer-aided approach in assessing intranodal vascularity for the differentiation of benign and malignant lymph nodes. MATERIALS AND METHODS: The present study retrospectively assessed 99 power Doppler ultrasound images of cervical lymph nodes and evaluated the degree of intranodal vascularity using qualitative subjective grading (QSG) and quantitative computer-aided (QCA) methods. The diagnostic accuracy of the two methods in distinguishing metastatic and reactive nodes and their inter- and intra-rater reliability in assessing intranodal vascularity were evaluated and compared. RESULTS: The results showed that the QCA method was more accurate than the QSG method with a significantly higher sensitivity (67.8â% and 61.9â%, respectively, pâ<â0.05) and specificity (73.3â% and 57.3â%, respectively, pâ<â0.05). Using the intranodal vascularity index as determined by the QCA approach, the optimum cut-off to differentiate metastatic and reactive cervical lymph nodes was 32â%. The QCA method showed higher inter- and intra-rater reliability than the QSG method. CONCLUSION: In the assessment of the degree of intranodal vascularity, the QCA method was more accurate and reliable than the QSG method in distinguishing metastatic and reactive lymph nodes.
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Interpretación de Imagen Asistida por Computador/métodos , Ganglios Linfáticos/irrigación sanguínea , Linfadenopatía/diagnóstico por imagen , Metástasis Linfática/diagnóstico por imagen , Clasificación del Tumor , Neoplasias de Oído, Nariz y Garganta/irrigación sanguínea , Neoplasias de Oído, Nariz y Garganta/diagnóstico por imagen , Ultrasonografía Doppler , Biopsia con Aguja Fina , Velocidad del Flujo Sanguíneo , Competencia Clínica , Diagnóstico Diferencial , Ganglios Linfáticos/patología , Metástasis Linfática/patología , Cuello/diagnóstico por imagen , Variaciones Dependientes del Observador , Neoplasias de Oído, Nariz y Garganta/patología , Reproducibilidad de los Resultados , Estudios RetrospectivosRESUMEN
BACKGROUND AND PURPOSE: Our previous nasopharyngeal carcinoma detection study, comparing MR imaging, endoscopy, and endoscopic biopsy, showed that MR imaging is a highly sensitive test that identifies nasopharyngeal carcinomas missed by endoscopy. However, at the close of that study, patients without biopsy-proved nasopharyngeal carcinoma nevertheless had shown suspicious abnormalities on endoscopy and/or MR imaging. The aim of this study was to determine whether there were any patients with undiagnosed nasopharyngeal carcinoma by obtaining long-term follow-up and to use these data to re-evaluate the diagnostic performance of MR imaging. MATERIALS AND METHODS: In the previous study, 246 patients referred to a hospital ear, nose, and throat clinic with suspected nasopharyngeal carcinoma, based on a wide range of clinical indications, had undergone MR imaging, endoscopy, and endoscopic biopsy, and 77 had biopsy-proved nasopharyngeal carcinoma. One hundred twenty-six of 169 patients without biopsy-proved nasopharyngeal carcinoma underwent re-examination of the nasopharynx after a minimum of 3 years, including 17 patients in whom a previous examination (MR imaging = 11; endoscopy = 7) had been positive for nasopharyngeal carcinoma, but the biopsy had been negative for it. Patients with nasopharyngeal carcinoma were identified by biopsy obtained in the previous and this follow-up study; patients without nasopharyngeal carcinoma were identified by the absence of a tumor on re-examination of the nasopharynx. The sensitivity and specificity of the previous investigations were updated and compared by using the Fisher exact test. RESULTS: One patient with a previous positive MR imaging finding was subsequently proved to have nasopharyngeal carcinoma. Nasopharyngeal carcinomas were not found in the remaining 125 patients at follow-up, and the previous positive findings for nasopharyngeal carcinoma on MR imaging and endoscopy were attributed to benign lymphoid hyperplasia. The diagnostic performances for the previous MR imaging, endoscopy, and endoscopic biopsy were 100%, 88%, and 94%, respectively, for sensitivity, and 92%, 94%, and 100%, respectively, for specificity; the differences between MR imaging and endoscopy were significant for sensitivity (P = .003) but not specificity (P = .617). CONCLUSIONS: MR imaging detected the 12% of nasopharyngeal carcinomas that were endoscopically invisible, including 1 cancer that remained endoscopically occult for several years. Lymphoid hyperplasia reduced the specificity of MR imaging.
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Imagen por Resonancia Magnética/métodos , Neoplasias Nasofaríngeas/diagnóstico , Adulto , Anciano , Biopsia/métodos , Carcinoma , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Procedimientos Quirúrgicos Otorrinolaringológicos/métodos , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
PURPOSE: Shear wave elastography (SWE) is a new technique which provides quantitative assessment of soft tissue stiffness. The aim of this study was to assess the reliability of SWE stiffness measurements and its usefulness in evaluating post-irradiation neck fibrosis. MATERIALS AND METHODS: 50 subjects (25 patients with previous radiotherapy to the neck and 25 sex and age-matched controls) were recruited for comparison of SWE stiffness measurements (Aixplorer, Supersonic Imagine). 30 subjects (16 healthy individuals and 14 post-irradiated patients) were recruited for a reliability study of SWE stiffness measurements. SWE stiffness measurements of the sternocleidomastoid muscle and the overlying subcutaneous tissues of the neck were made. The cross-sectional area and thickness of the sternocleidomastoid muscle and the overlying subcutaneous tissue thickness of the neck were also measured. The post-irradiation duration of the patients was recorded. RESULTS: The intraclass correlation coefficients for the intraoperator and interoperator reliability of deep and subcutaneous tissue SWE stiffness ranged from 0.90-0.99 and 0.77-0.94, respectively. The SWE stiffness measurements (mean +/- SD) of deep and subcutaneous tissues were significantly higher in the post-irradiated patients (64.6 ± 46.8 kPa and 63.9 ± 53.1 kPa, respectively) than the sex and age-matched controls (19.9 ± 7.8 kPa and 15.3 ± 8.37 respectively) (p < 0.001). The SWE stiffness increased with increasing post-irradiation therapy duration in the Kruskal Wallis test (p < 0.001) and correlated with muscle atrophy and subcutaneous tissue thinning (p < 0.01). CONCLUSION: SWE is a reliable technique and may potentially be an objective and specific tool in quantifying deep and subcutaneous tissue stiffness, which in turn reflects the severity of neck fibrosis.
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Diagnóstico por Imagen de Elasticidad/métodos , Cuello/efectos de la radiación , Traumatismos por Radiación/diagnóstico por imagen , Disección , Fibrosis , Humanos , Cuello/patología , Traumatismos por Radiación/patología , Ultrasonografía Intervencional/métodosRESUMEN
Hirayama disease is an uncommon cervical myelopathy associated with neck flexion. It has been postulated to be related to the anterior shifting of the posterior dura of the lower cervical dural canal during neck flexion, resulting in lower cervical cord atrophy with asymmetric flattening. We report a case of Hirayama disease in a 17-year-old Chinese man and demonstrate the use of dynamic flexion magnetic resonance imaging of the cervical spine in the diagnosis of the disease.
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Atrofias Musculares Espinales de la Infancia/diagnóstico , Adolescente , China , Duramadre/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Atrofia Muscular/patología , Neurofisiología , Atrofias Musculares Espinales de la Infancia/terapiaRESUMEN
Assessment of neck lymph nodes is essential in patients with head and neck cancers for predicting the patient's prognosis and selecting the appropriate treatment. Ultrasonography is a useful imaging tool in the assessment of neck lymph nodes. Greyscale ultrasonography assesses the size, distribution, and internal architecture of lymph nodes. Doppler ultrasonography evaluates the intranodal vascular pattern and resistance of lymph nodes. Contrast-enhanced ultrasonography provides information on lymph node parenchymal perfusion. Elastography allows qualitative and quantitative assessment of lymph node stiffness. This article reviews the value of greyscale, Doppler and contrast-enhanced ultrasonography as well as elastography in the assessment of malignant nodes in the neck.
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Medios de Contraste , Diagnóstico por Imagen de Elasticidad/métodos , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Aumento de la Imagen , Ganglios Linfáticos/diagnóstico por imagen , Ultrasonografía Doppler/métodos , Biopsia con Aguja Fina , Calcinosis/diagnóstico por imagen , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática , Cuello , NecrosisRESUMEN
Image-guided interventional procedures provide a safe way to diagnose and treat a variety of head and neck abnormalities. The procedure time is usually short, and most procedures can be performed on an outpatient basis. Knowledge about strengths and weaknesses, efficacy, potential complications, and pitfalls of these procedures allows the best treatment to be chosen for a particular lesion type. This review discusses some of the commonly performed interventional radiology procedures in a general radiology department in the management of patients with neoplastic diseases in the head and neck region.
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Neoplasias de Cabeza y Cuello/terapia , Radiología Intervencionista/métodos , Ultrasonografía Intervencional/métodos , Biopsia , Carcinoma/patología , Carcinoma Papilar , Ablación por Catéter/instrumentación , Ablación por Catéter/métodos , Etanol/administración & dosificación , Humanos , Metástasis Linfática , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/patología , Parálisis de los Pliegues Vocales/terapiaRESUMEN
This is a pictorial essay of unusual parotid gland lesions that may be encountered in routine clinical practice.
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Neoplasias de la Parótida/diagnóstico , Diagnóstico Diferencial , Diagnóstico por Imagen , Humanos , Imagen por Resonancia Magnética/métodos , Glándula Parótida/diagnóstico por imagen , Glándula Parótida/patología , Neoplasias de la Parótida/patología , Neoplasias de la Parótida/secundario , Tomografía Computarizada por Rayos X/métodos , UltrasonografíaRESUMEN
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.
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Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/terapia , Quimioradioterapia , Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/terapia , Anciano , Imagen de Difusión por Resonancia Magnética/normas , Monitoreo de Drogas/métodos , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Neoplasia Residual/patología , Neoplasia Residual/terapia , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Insuficiencia del TratamientoRESUMEN
White matter hyperintensities (WMH) are common in stroke. The influence of WMH on health-related quality of life (HRQoL) following a lacunar stroke is unknown. This study evaluated the impact of WMH on HRQoL in acute lacunar stroke. A cohort of 160 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a research assistant administered the Short Form-36 (SF-36) to assess HRQoL. The severity of WMH was evaluated with magnetic resonance imaging (MRI). In univariate analysis, the severity of deep WMH (DWMH) negatively correlated with patients' vitality (VT; p < 0.05), social function (SF; p < 0.001), role-emotional (RE; p < 0.01), mental health (MH; p < 0.01), and mental component summary (MCS; p < 0.001) scores of HRQoL. DWMH was independently associated with all of the above five SF-36 scores (p < 0.05) in linear regression analysis. These findings suggest that DWMH has a significant impact on the HRQoL of stroke survivors. The importance of DWMH in the long-term HRQoL in lacunar stroke warrants further investigation.
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Encéfalo/patología , Calidad de Vida/psicología , Accidente Vascular Cerebral Lacunar/patología , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , MasculinoRESUMEN
PURPOSE: To evaluate the reliability of shear wave ultrasound elastography (SWE) in the neck. MATERIALS AND METHODS: 176 neck lesions (40 thyroid, 56 lymph nodes, 46 salivary, 34 miscellaneous) identified in a routine US clinic underwent SWE by one or two blinded radiologists. For this study, SWE required the operator to acquire three 10 second dynamic colour-coded SWE cineloops per lesion, select one static image per cineloop, and place circular regions-of-interest within the entire lesion and stiffest part to generate 3 SWE measurements per static image. For logistical reasons, one radiologist evaluated all 176 lesions and the other evaluated 58 lesions. Both radiologists also reviewed 27 archived cineloops independently to assess SWE excluding practical technique. Reliability was assessed using intraclass correlation coefficients (ICCs) concordance correlation coefficients (CCCs) and coefficients of repeatability (CORs). RESULTS: Test-retest ICCs for the radiologist evaluating 176 lesions were 0.78â-â0.85 (fair-excellent agreement), CCCs were 0.85â-â0.88 (substantial agreement), and CORs were 14.9â-â36.1 kPa. For both radiologists evaluating 58 lesions, intra-rater and inter-rater ICCs were 0.65â-â0.78 and 0.72â-â0.77 respectively. For SWE excluding practical technique, inter-rater ICCs were 0.97â-â0.98 (excellent agreement). ICCs differed according to tissue, being higher in thyroid lesions than lymph nodes (pâ<â0.001), and higher in benign than malignant lesions (p values <â0.001). CONCLUSION: Intra- and inter-rater reliability of SWE is fair to excellent according to ICCs. SWE reliability is influenced appreciably by acquisition technique. Nevertheless, CORs for SWE are not negligible. To determine whether these results are acceptable clinically, further research is required to establish SWE stiffness values of normal and pathological tissues in the neck.
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Diagnóstico por Imagen de Elasticidad/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Cuello/diagnóstico por imagen , Enfermedades Otorrinolaringológicas/diagnóstico por imagen , Resistencia al Corte/fisiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Enfermedades de las Glándulas Salivales/diagnóstico por imagen , Sensibilidad y Especificidad , Estadística como Asunto , Enfermedades de la Tiroides/diagnóstico por imagen , Adulto JovenRESUMEN
OBJECTIVE: Vegetarians are more vascular-healthy but those with subnormal vitamin B-12 status have impaired arterial endothelial function and increased intima-media thickness. We aimed to study the impact of vitamin B-12 supplementation on these markers, in the vegetarians. DESIGN: Double-blind, placebo controlled, randomised crossover study. SETTING: Community dwelling vegetarians. PARTICIPANTS: Fifty healthy vegetarians (vegetarian diet for at least 6 years) were recruited. INTERVENTION: Vitamin B-12 (500 µg/day) or identical placebo were given for 12 weeks with 10 weeks of placebo-washout before crossover (n=43), and then open label vitamin B-12 for additional 24 weeks (n=41). MEASUREMENT: Flow-mediated dilation of brachial artery (FMD) and intima-media thickness (IMT) of carotid artery were measured by ultrasound. RESULTS: The mean age of the subjects was 45±9 years and 22 (44%) were male. Thirty-five subjects (70%) had serum B-12 levels <150 pmol/l. Vitamin B-12 supplementation significantly increased serum vitamin B-12 levels (p<0.0001) and lowered plasma homocysteine (p<0.05). After vitamin B-12 supplementation but not placebo, significant improvement of brachial FMD (6.3±1.8% to 6.9±1.9%; p<0.0001) and in carotid IMT (0.69±0.09 mm to 0.67±0.09 mm, p<0.05) were found, with further improvement in FMD (to 7.4±1.7%; p<0.0001) and IMT (to 0.65±0.09 mm; p<0.001) after 24 weeks open label vitamin B-12. There were no significant changes in blood pressures or lipid profiles. On multivariate analysis, changes in B-12 (ß=0.25; p=0.02) but not homocysteine were related to changes in FMD, (R=0.32; F value=3.19; p=0.028). CONCLUSIONS: Vitamin B-12 supplementation improved arterial function in vegetarians with subnormal vitamin B-12 levels, proposing a novel strategy for atherosclerosis prevention.
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Arterias/fisiopatología , Dieta Vegetariana/efectos adversos , Suplementos Dietéticos , Endotelio Vascular/fisiopatología , Deficiencia de Vitamina B 12/dietoterapia , Vitamina B 12/uso terapéutico , Adulto , Arterias/patología , Biomarcadores , Arteria Braquial/diagnóstico por imagen , Arteria Braquial/fisiopatología , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/patología , Grosor Intima-Media Carotídeo , Estudios Cruzados , Dieta Vegetariana/etnología , Método Doble Ciego , Endotelio Vascular/patología , Femenino , Homocisteína/sangre , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Vasodilatación , Vitamina B 12/sangre , Deficiencia de Vitamina B 12/etnología , Deficiencia de Vitamina B 12/etiología , Deficiencia de Vitamina B 12/fisiopatologíaRESUMEN
OBJECTIVES: The aim of this study was to explore the technical feasibility of T(1)ρ MRI for the liver, and to determine the normal range of liver T(1)ρ in healthy subjects at clinical 3 T. METHODS: There were 15 healthy volunteers. Three representative axial slices were selected to cut through the upper, middle and lower liver. A rotary echo spin-lock pulse was implemented in a two-dimensional fast-field echo sequence. Spin-lock frequency was 500 Hz, and the spin-lock times of 1, 10, 20, 30, 40 and 50 ms were used for T(1)ρ mapping. The images were acquired slice by slice during breath-holding. Regions of interest (ROIs; n=5) were manually placed on each slice of the liver parenchyma region, excluding artefacts and vessels. The mean value of these ROIs (n=15) was regarded as the liver T(1)ρ value for the subject. Six subjects were scanned once at fasting status; six subjects were scanned once 2 h post meal; three subjects were scanned twice at fasting status; and seven subjects were scanned twice 2 h post meal. RESULTS: When two readers measured the same 10 data sets, the interreader reproducibility (ICC: intraclass correlation coefficient) was 0.955. With the 10 subjects scanned twice, the ICC for scan-rescan reproducibility was 0.764. There was no significant difference for the liver T(1)ρ value at the fasting status (43.08±1.41 ms) and post-meal status (42.97±2.38 ms, p=0.867). Pooling together all the 32 scans in this study, the normal liver T(1)ρ value ranged from 38.6 to 48.3 ms (mean 43.0 ms, median 42.6 ms). CONCLUSION: It is feasible to obtain consistent liver T(1)ρ measurement for human subjects at 3 T.
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Imagen Eco-Planar/métodos , Aumento de la Imagen/métodos , Hígado/anatomía & histología , Adulto , Femenino , Humanos , Masculino , Proyectos Piloto , Valores de Referencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto JovenRESUMEN
UNLABELLED: The management of a neck mass is dictated by its nature, location and extent. Pathological diagnosis by fine needle aspiration cytology (FNAC) or core biopsy is often required before proceeding to definitive treatment. It is not uncommon for the cytology result to come back as inadequate for various reasons. The unique design of the end-cutting biopsy needle in our experience makes it a good choice for use in obtaining both transcutaneous and intraoral biopsy under ultrasound guidance of neck lesions and serves as a useful alternative or adjunct to FNAC. Although there is, as yet, only a limited evidence base about end-cutting in comparison to side-cutting needles, they carry several potential advantages. KEY POINTS: End-cutting needles are safe to use for lesions close to vital structures. End-cutting needles yield sufficient tissue samples in a single pass. End-cutting biopsy needles are a useful adjunct to FNAC.
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Biopsia con Aguja/instrumentación , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/patología , Cuello/diagnóstico por imagen , Cuello/patología , Cirugía Asistida por Computador/instrumentación , Ultrasonografía Intervencional/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , HumanosRESUMEN
OBJECTIVES: The femoral head is prone to osteonecrosis. This study investigated dynamic contrast-enhanced (DCE) MRI contrast washout features of the femoral head and compared the data with data from other bony compartments in normal rats. METHODS: 7-month-old Wistar rats were used. DCE MRI of the right hip (n=18), right knee (n=12) and lumbar spine (n=10) was performed after an intravenous bolus injection of Gd-DOTA (0.3 mmol kg(-1)). Temporal resolution was 0.6 s for hip and spine, and 0.3 s for knee. The total scan duration was 8 min for hip and spine, and 4.5 min for knee. The regions of interest for enhancement measurement included femoral head, proximal femoral diaphysis, distal femoral diaphysis and epiphysis, proximal tibial epiphysis and diaphysis, and lumbar vertebrae L1-5. RESULTS: Femoral head showed no enhancement signal decay during the DCE MRI period, while all other bony compartments showed a contrast washin phase followed by a contrast washout phase. In the knee joint, the contrast washout of the proximal tibia diaphysis was slower that of other bony compartments of the knee. CONCLUSION: Based on the evidence of delayed contrast washout, this study showed that blood perfusion in the femoral head could be compromised in normal rats.
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Medios de Contraste , Cabeza Femoral/irrigación sanguínea , Compuestos Heterocíclicos , Compuestos Organometálicos , Animales , Necrosis de la Cabeza Femoral/fisiopatología , Angiografía por Resonancia Magnética/métodos , Ratas , Ratas WistarRESUMEN
Falls are common among the elderly population. Examinations for the cause of falls are usually mundane, but may be challenging, leading to surprising diagnoses. We report on a previously healthy elderly man who presented with repeated falls and rapidly progressive limitations in mobility, in addition to a stutter. Neuroimaging was particularly helpful for making the diagnosis in this patient.
Asunto(s)
Accidentes por Caídas , Anciano , Degeneración Lobar Frontotemporal/complicaciones , Humanos , Imagen por Resonancia Magnética , Masculino , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
We report a rare case of a 32-year-old male with live extralymphatic filarial infestation presenting as a facial subcutaneous soft-tissue swelling. To the best of our knowledge these imaging findings have not been previously reported in the head and neck region in the existing English language literature. Real-time high-resolution ultrasonography revealed a solitary well-defined subcutaneous cystic lesion over the right zygomatic arch. It showed multiple linear, echogenic, undulating structures exhibiting a persistent twirling motion during the examination. This typical ultrasonographic appearance was consistent with the filarial dance sign (FDS) of live adult filarial worms. Subsequent MRI confirmed the cystic and solitary nature of the lesion. Complete excision of the cyst was performed, which revealed intracystic straw-coloured fluid and multiple white-coloured adult worms within the lesion. Histopathological examination confirmed multiple adult filarial worms with surrounding reactive inflammatory changes. In an endemic region, identification of the FDS in any normal anatomical structure or abnormal swelling, however remote or unusual the location within the body, should strongly suggest the diagnosis of live active filarial infestation. In view of the increasing migratory trends in the global population, it is imperative for radiologists in all countries to be aware of the typical imaging findings of this disease to arrive at the correct diagnosis.