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1.
Radiographics ; 42(7): E216-E223, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36269668

RESUMEN

The increasing usage of peripherally inserted central catheters (PICCs) in medical imaging departments has led to a corresponding increase in cases of central line-associated bloodstream infection (CLABSI). However, this condition is preventable with proper monitoring and use of aseptic techniques. A Comprehensive Unit-based Safety Program (CUSP) is a quality improvement (QI) measure implemented by health care institutions to reduce the incidence of CLABSI. However, effective strategies have yet to be established. The authors describe a QI project that evaluated the implementation of CUSP at a teaching hospital to reduce PICC-associated bloodstream infection (BSI). The framework consists of a five-step process: understand and train staff on the science of safety, assemble a team, engage senior executives, identify defects through sensemaking, and implement teamwork and communication strategies in a series of related and sequential steps that use QI tools. Targets were identified for improvement from existing processes, and the workflow was reengineered. Nine months after the start of the CUSP intervention, PICC-associated BSI incidence in the hospital had been reduced from 3.4 to 2.7 per 1000 central lines days after intervention. The incidence of BSI was also reduced correspondingly from 8.8% to 5.9%. The QI processes in this study may be adopted by other hospitals, as they involve minimal cost with significant impact on patient safety and well-being. The QI sequential steps described capture the implementation processes that can be modified for use in other department settings where patient safety could be compromised. Online supplemental material is available for this article. ©RSNA, 2022.


Asunto(s)
Infecciones Relacionadas con Catéteres , Cateterismo Venoso Central , Sepsis , Humanos , Infecciones Relacionadas con Catéteres/epidemiología , Infecciones Relacionadas con Catéteres/prevención & control , Cateterismo Venoso Central/métodos , Mejoramiento de la Calidad , Factores de Riesgo , Sepsis/epidemiología , Sepsis/prevención & control
2.
Nephrology (Carlton) ; 26(1): 38-45, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33058334

RESUMEN

AIM: Renal biopsy is the gold standard for the histological characterization of chronic kidney disease (CKD), of which renal fibrosis is a dominant component, affecting its stiffness. The aim of this study was to investigate the correlation between kidney stiffness obtained by shear wave elastography (SWE) and renal histological fibrosis. METHODS: Shear wave elastography assessments were performed in 75 CKD patients who underwent renal biopsy. The SWE-derived estimates of the tissue Young's modulus (YM), given as kilopascals (kPa), were measured. YM was correlated to patients' renal histological scores, broadly categorized into glomerular, tubulointerstitial and vascular scores. RESULTS: Young's modulus correlates significantly with tubulointerstitial score (ρ = 0.442, P < .001) and glomerular score (ρ = 0.375, P = .001). Patients with no glomerular sclerosis showed lower mean YM measurements compared to those with glomerular sclerosis. The mean YM increased as the percentage of interstitial fibrosis and tubular atrophy increased. The area under the receiver operating characteristic curve (ROC) for SWE in differentiating between mildly and moderately impaired kidneys was 0.702. CONCLUSION: Shear wave elastography accurately detects chronic renal damage resulting from glomerular sclerosis, interstitial fibrosis and tubular atrophy, using the optimal cut-off YM value of ≥5.81 kPa.


Asunto(s)
Biopsia/métodos , Diagnóstico por Imagen de Elasticidad/métodos , Riñón , Insuficiencia Renal Crónica/diagnóstico , Atrofia , Módulo de Elasticidad , Elasticidad/fisiología , Femenino , Fibrosis , Humanos , Riñón/diagnóstico por imagen , Riñón/patología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Ultrasonografía Intervencional/métodos
3.
Clin Gastroenterol Hepatol ; 18(4): 945-953.e2, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31442603

RESUMEN

BACKGROUND & AIMS: HepaFat-Scan is a magnetic resonance imaging-based method for quantification of hepatic steatosis by volumetric liver fat fraction (VLFF) measurement. We aimed to validate VLFF and to compare it with controlled attenuation parameter (CAP) for determination of hepatic steatosis grade in patients with NAFLD, using histopathology and stereologic analyses of biopsies as the reference standard. METHODS: We performed a prospective study of consecutive adults with NAFLD who were scheduled for a liver biopsy at a tertiary hospital in Malaysia. Patients underwent VLFF and CAP measurements on the same day as their liver biopsy. Histopathology analyses of liver biopsy specimens were reported according to the Nonalcoholic Steatohepatitis Clinical Research Network scoring system. Stereologic analysis was performed using grid-point counting method combined with the Delesse principle. RESULTS: We analyzed data from 97 patients (mean age 57.0 ± 10.1 years; 44.33% male; 91.8% obese; 95.9% centrally obese). Based on histopathology analysis, the area under receiver operating characteristic curve (AUROC) for VLFF in detection of steatosis grade ≥S2 was 0.92 and for CAP the AUROC was 0.65 (P < .001). Based on stereological analysis, the AUROC for VLFF for detection of steatosis grade ≥S2 was 0.92 and for CAP the AUROC was 0.63, (P = .002); for identification of steatosis grade S3, the AUROC for VLFF was 0.92 and for CAP the AUROC was 0.68 (P < .001). CONCLUSIONS: In a prospective study of patients with NAFLD undergoing liver biopsy analysis, we found VLFF to more accurately determine grade of hepatic steatosis than CAP.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Enfermedad del Hígado Graso no Alcohólico , Adulto , Área Bajo la Curva , Biopsia , Femenino , Humanos , Hígado/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Estudios Prospectivos , Curva ROC
4.
J Gastroenterol Hepatol ; 35(1): 135-141, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31310032

RESUMEN

BACKGROUND AND AIM: Transient elastography (TE) and point shear wave elastography (pSWE) are noninvasive methods to diagnose fibrosis stage in patients with chronic liver disease. The aim of this study is to compare the accuracy of the two methods to diagnose fibrosis stage in non-alcoholic fatty liver disease (NAFLD) and to study the intra-observer and inter-observer variability when the examinations were performed by healthcare personnel of different backgrounds. METHODS: Consecutive NAFLD patients who underwent liver biopsy were enrolled in this study and had two sets each of pSWE and TE examinations by a nurse and a doctor on the same day of liver biopsy procedure. The medians of the four sets of pSWE and TE were used for evaluation of diagnostic accuracy using area under receiver operating characteristic curve (AUROC). Intra-observer and inter-observer variability was analyzed using intraclass correlation coefficients. RESULTS: Data for 100 NAFLD patients (mean age 57.1 ± 10.2 years; male 46.0%) were analyzed. The AUROC of TE for diagnosis of fibrosis stage ≥ F1, ≥ F2, ≥ F3, and F4 was 0.89, 0.83, 0.83, and 0.89, respectively. The corresponding AUROC of pSWE was 0.80, 0.72, 0.69, and 0.79, respectively. TE was significantly better than pSWE for the diagnosis of fibrosis stages ≥ F2 and ≥ F3. The intra-observer and inter-observer variability of TE and pSWE measurements by the nurse and doctor was excellent with intraclass correlation coefficient > 0.96. CONCLUSION: Transient elastography was significantly better than pSWE for the diagnosis of fibrosis stage ≥ F2 and ≥ F3. Both TE and pSWE had excellent intra-observer and inter-observer variability when performed by healthcare personnel of different backgrounds.


Asunto(s)
Diagnóstico por Imagen de Elasticidad/métodos , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Enfermedad del Hígado Graso no Alcohólico/patología , Femenino , Fibrosis , Humanos , Masculino , Persona de Mediana Edad
5.
J Gastroenterol Hepatol ; 28(8): 1375-83, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23517307

RESUMEN

BACKGROUND AND AIM: There is currently no published study comparing prevalence of non-alcoholic fatty liver disease (NAFLD) and associated factors among diabetics of different ethnicity in the Asia-Pacific region. METHODS: Cross-sectional study of consecutive patients in the Diabetic Clinic in University of Malaya Medical Centre. The Global Physical Activity Questionnaire and a semiquantitative food-frequency questionnaire were used to assess physical activity and dietary intake, respectively. Diagnosis of NAFLD was ultrasound-based and following exclusion of significant alcohol intake. RESULTS: Data for 399 patients were analyzed (mean age 62.3 ± 10.5 years, 43.1% men). The racial distribution was Chinese 43.6%, Indian 33.1%, Malay 22.3%, and others 1.0%. The prevalence of NAFLD was 49.6%. On univariate analysis, factors associated with NAFLD were age < 65 years, race, obesity, central obesity, glycated hemoglobin ≥ 7.0%, and elevated serum alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase levels. Patients with low physical activity were more likely to have NAFLD (odds ratio [OR] = 1.67, 95% confidence interval [CI] = 1.06-2.63, P = 0.020). The prevalence of NAFLD was highest among Malays (60.7%), followed by Indians (51.5%), and lowest among Chinese (42.0%) consistent with higher prevalence of central obesity and higher percentage calorie intake from fat in the former groups of patients. On multivariate analysis, independent factors associated with NAFLD were central obesity (OR = 2.20, 95% CI = 1.29-3.75, P = 0.004) and elevated serum ALT level (OR = 1.98, 95% CI = 1.21-3.25, P = 0.007). CONCLUSIONS: NAFLD was seen in half of a cohort of diabetic patients and was independently associated with central obesity and elevated serum ALT level. Prevalence of NAFLD was different and paralleled the difference in prevalence of central obesity and in percentage calorie intake from fat among the different ethnic groups.


Asunto(s)
Complicaciones de la Diabetes , Hígado Graso/etnología , Hígado Graso/epidemiología , Hospitales Universitarios/estadística & datos numéricos , Anciano , Alanina Transaminasa/sangre , China/etnología , Estudios de Cohortes , Estudios Transversales , Grasas de la Dieta , Ingestión de Energía , Hígado Graso/diagnóstico , Hígado Graso/etiología , Femenino , Predicción , Humanos , India/etnología , Malasia/epidemiología , Malasia/etnología , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico , Obesidad/epidemiología , Obesidad/etnología , Prevalencia
6.
Br J Radiol ; 96(1144): 20220288, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36802861

RESUMEN

OBJECTIVE: Many studies have conflicting findings in using shear wave elastography (SWE) to assess renal fibrosis. This study reviews the use of SWE to evaluate pathological changes in native kidneys and renal allografts. It also tries to elucidate the confounding factors and care taken to ensure the results are consistent and reliable. METHODS: The review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Literature search was conducted in Pubmed, Web of Science and Scopus database up to 23 October 2021. To evaluate risk and bias applicability, the Cochrane risk-of bias tool and GRADE was used. The review was registered under PROSPERO CRD42021265303. RESULTS: A total of 2921 articles were identified. 104 full texts were examined and 26 studies included in systematic review. 11 studies performed on native kidneys and 15 studies on transplanted kidney. A wide range of impact factors was found that affect the accuracy of SWE of renal fibrosis in adult patients. CONCLUSIONS: Compared to point SWE, two-dimensional SWE with elastogram could enable better selection of the region of interest in kidneys, leading to reproducible results. Tracking waves were attenuated as the depth from skin to region of interest increased, therefore, SWE is not recommended for overweight or obese patients. Variable transducer forces might also affect SWE reproducibility, thus, training of operators to ensure consistent operator-dependent transducer forces may be helpful. ADVANCES IN KNOWLEDGE: This review provides a holistic insight on the efficiency of using SWE in evaluating pathological changes in native and transplanted kidneys, thereby contributing to the knowledge of its utilisation in clinical practice.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Humanos , Adulto , Diagnóstico por Imagen de Elasticidad/métodos , Reproducibilidad de los Resultados , Ultrasonografía , Riñón/diagnóstico por imagen , Fibrosis , Cirrosis Hepática
7.
Acad Radiol ; 29 Suppl 1: S69-S78, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-33926793

RESUMEN

OBJECTIVES: This study evaluates the diagnostic performance of shear wave elastography (SWE) in differentiating between benign and axillary lymph node (ALN) metastasis in breast carcinoma. MATERIALS AND METHODS: Breast lesions and axillae of 107 patients were assessed using B-mode ultrasound and SWE. Histopathology was the diagnostic gold standard. RESULTS: In metastatic axillary lymph nodes, qualitative SWE using color patterns had the highest area under curve (AUC) value, followed by B-mode Ultrasound (cortical thickening >3 mm) and quantitative SWE using Emax of 15.2 kPa (AUC of 81.3%, 70.1%, and 61.2%, respectively). Qualitative SWE exhibited better diagnostic performance than the other two parameters, with sensitivity of 96.0% and specificity of 56.1%. Combination of B-mode Ultrasound (using cortical thickness of >3 mm as cut-off point) and qualitative SWE (Color patterns of 2 to 4) showed sensitivity of 71.6%, specificity of 95%, PPV of 96%, NPV of 66.7%, and accuracy of 80.4%. CONCLUSION: Qualitative SWE assessment exhibited higher accuracy compared to quantitative values. Qualitative SWE as an adjunct to B-mode ultrasound can further improve the diagnostic accuracy of metastatic ALN in breast cancer.


Asunto(s)
Neoplasias de la Mama , Diagnóstico por Imagen de Elasticidad , Metástasis Linfática , Neoplasias de la Mama/patología , Femenino , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Ganglios Linfáticos/patología , Metástasis Linfática/diagnóstico por imagen , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
8.
Eur J Radiol ; 157: 110591, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36356463

RESUMEN

PURPOSE: To develop and validate a machine learning (ML) model for the classification of breast lesions on ultrasound images. METHOD: In the present study, three separate data cohorts containing 1288 breast lesions from three countries (Malaysia, Iran, and Turkey) were utilized for MLmodel development and external validation. The model was trained on ultrasound images of 725 breast lesions, and validation was done separately on the remaining data. An expert radiologist and a radiology resident classified the lesions based on the BI-RADS lexicon. Thirteen morphometric features were selected from a contour of the lesion and underwent a three-step feature selection process. Five features were chosen to be fed into the model separately and combined with the imaging signs mentioned in the BI-RADS reference guide. A support vector classifier was trained and optimized. RESULTS: The diagnostic profile of the model with various input data was compared to the expert radiologist and radiology resident. The agreement of each approach with histopathologic specimens was also determined. Based on BI-RADS and morphometric features, the model achieved an area under the receiver operating characteristic (ROC) curve (AUC) of 0.885, which is higher than the expert radiologist and radiology resident performances with AUC of 0.814 and 0.632, respectively in all cohorts. DeLong's test also showed that the AUC of the ML protocol was significantly different from that of the expert radiologist (ΔAUCs = 0.071, 95%CI: (0.056, 0.086), P = 0.005). CONCLUSIONS: These results support the possible role of morphometric features in enhancing the already well-excepted classification schemes.


Asunto(s)
Neoplasias de la Mama , Ultrasonografía Mamaria , Femenino , Humanos , Ultrasonografía Mamaria/métodos , Neoplasias de la Mama/diagnóstico por imagen , Inteligencia Artificial , Mama/diagnóstico por imagen , Ultrasonografía
9.
Sci Rep ; 11(1): 129, 2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33420200

RESUMEN

This study aims to evaluate the diagnostic accuracy of digital breast tomosynthesis-guided vacuum assisted breast biopsy (DBT-VABB) of screening detected suspicious mammographic abnormalities comprising of calcifications, asymmetric densities, architectural distortions and spiculated masses. In this institutionally approved study, a total of 170 (n = 170) DBT-VABB were performed, 153 (90%) were for calcifications, 8 (4.7%) for spiculated mass, 5 (2.9%) for asymmetric density and 4 (2.4%) for architectural distortion. All these lesions were not detected on the corresponding ultrasound. Histopathology results revealed 140 (82.4%) benign, 9 (5.3%) borderline and 21 (12.4%) malignant lesions. The total upgrade rate at surgery was 40% for atypical ductal hyperplasia and 5.9% for ductal carcinoma in-situ. 3.6% discordant benign lesions showed no upgrade. DBT-VABB showed 100% specificity, 91.3% sensitivity and 100% positive predictive value (PPV) for detecting malignant lesions. The negative predictive value (NPV) was 80%. 2 (1.2%) patients had mild complications and 1 (0.6%) had severe pain. Our study showed that DBT-VABB was a safe and reliable method, with high sensitivity, specificity, PPV and NPV in the diagnosis of non-palpable benign and malignant breast lesions. Our data also confirmed the accuracy of DBT-VABB in detecting malignant lesions and we suggest further surgical excision in borderline lesions for a more accurate diagnostic evaluation.


Asunto(s)
Biopsia/métodos , Mama/diagnóstico por imagen , Detección Precoz del Cáncer/métodos , Mamografía/métodos , Adulto , Anciano , Biopsia/instrumentación , Mama/patología , Mama/cirugía , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Calcinosis/diagnóstico por imagen , Calcinosis/patología , Calcinosis/cirugía , Estudios Transversales , Detección Precoz del Cáncer/instrumentación , Femenino , Humanos , Mamografía/instrumentación , Persona de Mediana Edad , Estudios Retrospectivos , Ultrasonografía/métodos
10.
Eur J Breast Health ; 17(2): 197-199, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33870121

RESUMEN

Desmoid type fibromatosis of the breast is a rare stromal tumor that accounts for <0.2% of all breast tumors. Bilateral and multicentric lesions are extremely rare, with only less than ten cases reported in the literature. Although benign, it is locally aggressive with frequent recurrence in up to almost one-third of the cases. We experienced our first case of bilateral multicentric breast fibromatosis in a 19-year-old woman, with a paternal aunt diagnosed with breast cancer at age 30, who presented to our institution with the chief complaint of retracted nipples for 1 year. The patient denied any history of trauma to her chest. Sonography showed suspicious bilateral hypoechoic masses. Magnetic resonance imaging (MRI) was performed for further evaluation because of the extensive involvement of both the breasts. This report aimed to illustrate the main clinical, radiological, and histopathological characteristics of this rare disease to increase awareness of this entity and discuss the role of MRI.

11.
J Med Imaging Radiat Sci ; 52(2): 257-264, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33531272

RESUMEN

INTRODUCTION: Fixed volume (FV) contrast media administration during CT examination is the standard practice in most healthcare institutions. We aim to validate a customised weight-based volume (WBV) method and compare it to the conventional FV methods, introduced in a regional setting. METHODS: 220 patients underwent CT of the chest, abdomen and pelvis (CAP) using a standard FV protocol, and subsequently, a customised 1.0 mL/kg WBV protocol within one year. Both image sets were assessed for contrast enhancement using CT attenuation at selected regions-of-interest (ROIs). The visual image quality was evaluated by three radiologists using a 4-point Likert scale. Quantitative CT attenuation was correlated with the visual quality assessment to determine the HU's enhancement indicative of the image quality grades. Contrast media usage was calculated to estimate cost-savings from both protocols. RESULTS: Mean patient age was 61 ± 14 years, and weight was 56.1 ± 8.7 kg. FV protocol produced higher contrast enhancement than WBV, p < 0.001. CT images' overall contrast enhancement was negatively correlated with body weight for FV protocol while the WBV protocol produced more consistent enhancement across different body weight. More than 90% of the images from both protocols were graded "Excellent". WBV protocol also enabled a 28% cost reduction with cost savings of US$1238. CONCLUSION: The customised WBV protocol produced CT images which were comparable to FV protocol for CT CAP examinations. A median CT value of 100 HU can be an indicator of good image quality for the WBV protocol.


Asunto(s)
Abdomen , Medios de Contraste , Anciano , Humanos , Persona de Mediana Edad , Pelvis/diagnóstico por imagen , Estudios Prospectivos , Tomografía Computarizada por Rayos X
12.
Ultrasound Med Biol ; 46(1): 34-45, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31594681

RESUMEN

Tissue elasticity is related to the pathologic state of kidneys and can be measured using shear wave elastography (SWE). However, SWE quantification has not been rigorously validated. The aim of this study was to evaluate the accuracy of SWE-measured stiffness and the effect of tissue anisotropy on SWE measurements. Point SWE (pSWE), 2-D SWE and dynamic mechanical analysis (DMA) were used to measure stiffness and evaluate the effect of tissue anisotropy on the measurements. SWE and DMA were performed on phantoms of different gelatin concentrations. In the tissue anisotropy study, SWE and DMA were performed on the outer cortex of sheep kidneys. In the in vivo study, 15 patients with different levels of interstitial fibrosis were recruited for pSWE measurements. Another 10 healthy volunteers were recruited for tissue anisotropy studies. SWE imaging revealed a non-linear increase with gelatin concentration. There was a significant correlation between pSWE and 2-D SWE, leading to the establishment of a linear regression equation between the two SWE ultrasound measurements. In the anisotropy study, the median difference in stiffness between shear waves oriented at 0° and 90° towards the pyramid axis was significant. In the in vivo study, there was a strong positive linear correlation between pSWE and the percentage of interstitial fibrosis. There was a significant difference in the Young's modulus (YM) between severities of fibrosis. The mean YM values were lower in control patients than in patients with mild, moderate and severe fibrosis. YM values were also significantly higher when shear waves were oriented at 0° toward the pyramid axis. Tissue stiffness and anisotropy affects SWE measurements. These factors should be recognized before applying SWE for the interpretation of measured values.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Cirrosis Hepática/diagnóstico por imagen , Adulto , Animales , Anisotropía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fantasmas de Imagen , Ovinos
13.
Ultrasound Med Biol ; 45(6): 1417-1426, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30962016

RESUMEN

The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for 51Cr-ethylenediaminetetraacetic acid GFR and 99mTc-dimercaptosuccinic acid renal scintigraphy were included. Young's modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients' GFR and renal scintigraphy results. Spearman correlation coefficients between SWE and GFR were negative for the right (r = -0.635, p < 0.0001) and left (r = -0.817, p < 0.0001) kidneys. Positive correlations between left renal cortical thickness (r = 0.381, p = 0.04) and left kidney volume (r = 0.356, p = 0.019) with GFR were reported. SWE correctly predicted the dominant functioning kidney in 94.7% of cases. The area under the receiver operating characteristic curve for SWE (0.800) was superior to that for conventional ultrasound (0.252-0.415). The cutoff value of ≥5.52 kPa suggested a kidney function ≤60 mL/min/1.73 m2 (82.4% sensitivity and 76.2% specificity). SWE has advantages over conventional ultrasound in assessing kidney function and distinguishing the dominant functioning kidney.


Asunto(s)
Radioisótopos de Cromo , Ácido Edético , Riñón/diagnóstico por imagen , Succímero , Tecnecio , Ultrasonografía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Módulo de Elasticidad , Diagnóstico por Imagen de Elasticidad/métodos , Femenino , Tasa de Filtración Glomerular/fisiología , Humanos , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Cintigrafía/métodos , Sensibilidad y Especificidad
14.
Br J Radiol ; 91(1089): 20180235, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29869920

RESUMEN

OBJECTIVE: To investigate the use of shear wave elastography (SWE)-derived estimates of Young's modulus (YM) as an indicator to detect abnormal renal tissue diagnosed by estimated glomerular filtration rate (eGFR). METHODS: The study comprised 106 chronic kidney disease (CKD) patients and 203 control subjects. Conventional ultrasound was performed to measure the kidney length and cortical thickness. SWE imaging was performed to measure renal parenchymal stiffness. Diagnostic performance of SWE and conventional ultrasound were correlated with serum creatinine, urea levels and eGFR. RESULTS: Pearson's correlation coefficient revealed a negative correlation between YM measurements and eGFR (r = -0.576, p < 0.0001). Positive correlations between YM measurements and age (r = 0.321, p < 0.05), serum creatinine (r = 0.375, p < 0.0001) and urea (r = 0.287, p < 0.0001) were also observed. The area under the receiver operating characteristic curve for SWE (0.87) was superior to conventional ultrasound alone (0.35-0.37). The cut-off value of less or equal to 4.31 kPa suggested a non-diseased kidney (80.3% sensitivity, 79.5% specificity). CONCLUSION: SWE was superior to renal length and cortical thickness in detecting CKD. A value of 4.31 kPa or less showed good accuracy in determining whether a kidney was diseased or not. Advances in knowledge: On SWE, CKD patients show greater renal parenchymal stiffness than non-CKD patients. Determining a cut-off value between normal and diseased renal parenchyma may help in early non-invasive detection and management of CKD.


Asunto(s)
Diagnóstico por Imagen de Elasticidad/métodos , Riñón/diagnóstico por imagen , Insuficiencia Renal Crónica/diagnóstico por imagen , Estudios de Casos y Controles , Femenino , Tasa de Filtración Glomerular , Humanos , Riñón/patología , Corteza Renal/anatomía & histología , Masculino , Persona de Mediana Edad , Curva ROC , Valores de Referencia , Insuficiencia Renal Crónica/clasificación , Insuficiencia Renal Crónica/patología
16.
Comput Methods Programs Biomed ; 166: 91-98, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30415722

RESUMEN

BACKGROUND AND OBJECTIVE: Liver fibrosis is a type of chronic liver injury that is characterized by an excessive deposition of extracellular matrix protein. Early detection of liver fibrosis may prevent further growth toward liver cirrhosis and hepatocellular carcinoma. In the past, the only method to assess liver fibrosis was through biopsy, but this examination is invasive, expensive, prone to sampling errors, and may cause complications such as bleeding. Ultrasound-based elastography is a promising tool to measure tissue elasticity in real time; however, this technology requires an upgrade of the ultrasound system and software. In this study, a novel computer-aided diagnosis tool is proposed to automatically detect and classify the various stages of liver fibrosis based upon conventional B-mode ultrasound images. METHODS: The proposed method uses a 2D contourlet transform and a set of texture features that are efficiently extracted from the transformed image. Then, the combination of a kernel discriminant analysis (KDA)-based feature reduction technique and analysis of variance (ANOVA)-based feature ranking technique was used, and the images were then classified into various stages of liver fibrosis. RESULTS: Our 2D contourlet transform and texture feature analysis approach achieved a 91.46% accuracy using only four features input to the probabilistic neural network classifier, to classify the five stages of liver fibrosis. It also achieved a 92.16% sensitivity and 88.92% specificity for the same model. The evaluation was done on a database of 762 ultrasound images belonging to five different stages of liver fibrosis. CONCLUSIONS: The findings suggest that the proposed method can be useful to automatically detect and classify liver fibrosis, which would greatly assist clinicians in making an accurate diagnosis.


Asunto(s)
Cirrosis Hepática/fisiopatología , Hígado/fisiopatología , Adulto , Anciano , Algoritmos , Diagnóstico por Imagen de Elasticidad , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Hígado/diagnóstico por imagen , Cirrosis Hepática/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , Reconocimiento de Normas Patrones Automatizadas , Probabilidad , Sensibilidad y Especificidad , Programas Informáticos , Ultrasonografía
17.
Comput Biol Med ; 94: 11-18, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29353161

RESUMEN

Liver is the heaviest internal organ of the human body and performs many vital functions. Prolonged cirrhosis and fatty liver disease may lead to the formation of benign or malignant lesions in this organ, and an early and reliable evaluation of these conditions can improve treatment outcomes. Ultrasound imaging is a safe, non-invasive, and cost-effective way of diagnosing liver lesions. However, this technique has limited performance in determining the nature of the lesions. This study initiates a computer-aided diagnosis (CAD) system to aid radiologists in an objective and more reliable interpretation of ultrasound images of liver lesions. In this work, we have employed radon transform and bi-directional empirical mode decomposition (BEMD) to extract features from the focal liver lesions. After which, the extracted features were subjected to particle swarm optimization (PSO) technique for the selection of a set of optimized features for classification. Our automated CAD system can differentiate normal, malignant, and benign liver lesions using machine learning algorithms. It was trained using 78 normal, 26 benign and 36 malignant focal lesions of the liver. The accuracy, sensitivity, and specificity of lesion classification were 92.95%, 90.80%, and 97.44%, respectively. The proposed CAD system is fully automatic as no segmentation of region-of-interest (ROI) is required.


Asunto(s)
Diagnóstico por Computador/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Cirrosis Hepática , Neoplasias Hepáticas , Aprendizaje Automático , Adulto , Femenino , Humanos , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Ultrasonografía
18.
PLoS One ; 13(9): e0203469, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30216346

RESUMEN

BACKGROUND: Breast cancer risk factors have been examined extensively in Western setting and more developed Asian cities/countries. However, there are limited data on developing Asian countries. The purpose of this study was to examine breast cancer risk factors and the change of selected risk factors across birth cohorts in Malaysian women. METHODS: An unmatched hospital based case-control study was conducted from October 2002 to December 2016 in Selangor, Malaysia. A total of 3,683 cases and 3,980 controls were included in this study. Unconditional logistic regressions, adjusted for potential confounding factors, were conducted. The breast cancer risk factors were compared across four birth cohorts by ethnicity. RESULTS: Ever breastfed, longer breastfeeding duration, a higher soymilk and soy product intake, and a higher level of physical activity were associated with lower risk of breast cancer. Chinese had the lowest breastfeeding rate, shortest breastfeeding duration, lowest parity and highest age of first full term pregnancy. CONCLUSIONS: Our study shows that breastfeeding, soy intake and physical activity are modifiable risk factors for breast cancer. With the increasing incidence of breast cancer there is an urgent need to educate the women about lifestyle intervention they can take to reduce their breast cancer risk.


Asunto(s)
Neoplasias de la Mama/epidemiología , Adulto , Anciano , Lactancia Materna , Estudios de Casos y Controles , Femenino , Humanos , Malasia/epidemiología , Persona de Mediana Edad , Factores de Riesgo , Proteínas de Soja/efectos adversos
19.
PLoS One ; 12(6): e0179895, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28658309

RESUMEN

OBJECTIVES: This study assesses the whole brain microstructural integrity of white matter tracts (WMT) among older individuals with a history of falls compared to non-fallers. METHODS: 85 participants (43 fallers, 42 non-fallers) were evaluated with conventional MRI and diffusion tensor imaging (DTI) sequences of the brain. DTI metrics were obtained from selected WMT using tract-based spatial statistics (TBSS) method. This was followed by binary logistic regression to investigate the clinical variables that could act as confounding elements on the outcomes. The TBSS analysis was then repeated, but this time including all significant predictor variables from the regression analysis as TBSS covariates. RESULTS: The mean diffusivity (MD) and axial diffusivity (AD) and to a lesser extent radial diffusivity (RD) values of the projection fibers and commissural bundles were significantly different in fallers (p < 0.05) compared to non-fallers. However, the final logistic regression model obtained showed that only functional reach, white matter lesion volume, hypertension and orthostatic hypotension demonstrated statistical significant differences between fallers and non-fallers. No significant differences were found in the DTI metrics when taking into account age and the four variables as covariates in the repeated analysis. CONCLUSION: This DTI study of 85 subjects, do not support DTI metrics as a singular factor that contributes independently to the fall outcomes. Other clinical and imaging factors have to be taken into account.


Asunto(s)
Accidentes por Caídas , Sustancia Blanca/ultraestructura , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Imagen de Difusión Tensora , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Factores de Riesgo , Sustancia Blanca/diagnóstico por imagen
20.
Springerplus ; 5(1): 943, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27386387

RESUMEN

BACKGROUND: Deep vein thrombosis (DVT) has been independently associated with both malignant diseases and orthopaedic surgery. Therefore, orthopaedic oncology patients may be at a high risk for thromboembolic events. However, less emphasis is given to this group of patients compared to the patients undergoing total hip and knee replacement. The objective of this study is to determine the incidence of DVT and their risk factors in patients undergoing orthopaedic oncology lower limb surgery without prophylaxis. QUESTIONS/PURPOSES: (1) What is the incidence of DVT in patients who underwent orthopaedic oncology surgery for the lower limb? (2) What are the risk factors related to DVT in patients who underwent oncology surgery of the lower limb surgery? (3) This is a pilot study to determine if further trial is warranted. METHODS: This is a prospective study. All sequential patients undergoing orthopaedic oncology operations from the period of 1st October 2013 till 30th September 2014 were recruited for the study with their consent. Their demographic data, diagnosis and surgery were documented. Thirty-eight patients who underwent lower limb surgeries for orthopaedic oncology indications were included in the study. No tourniquet was used in these lower limb surgeries. There were 24 men and 14 women with a mean age of 36 years (11-75). All potential risk factors were also identified and documented. All patients were not given any form of DVT prophylaxis (mechanical and chemical) before and after operation as this is a standard protocol in our center and a Medical Ethics Committee approval was taken for this study. DVT surveillance was performed 1 day before operation and 2 weeks after operation with ultrasound Doppler. Patients diagnosed with DVT via ultrasound Doppler were subsequently scheduled for CTPA to look for pulmonary embolism (PE). RESULTS: DVT was detected in two patients (5 %). Both patients were asymptomatic and they both had proximal thrombosis. One patient (2.6 %) was diagnosed with non-fatal PE and was asymptomatic. PE was detected incidentally by staging computed tomography scan and the patient had negative ultrasound Doppler of the operated and non-operated limb for DVT. We did not carry out a statistical analysis as the study population with DVT and pulmonary embolism is small. CONCLUSIONS: The incidence of DVT in patients after undergoing orthopaedic oncology lower limb surgery was low even without prophylaxis at our center. Further investigation with larger sample size is needed to validate our results and identify the risk factors. LEVEL OF EVIDENCE: Level III descriptive study.

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