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1.
Heliyon ; 9(5): e16408, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37251870

RESUMEN

Background: Chromosome analysis is laborious and time-consuming. Automated methods can significantly increase the efficiency of chromosome analysis. For the automated analysis of chromosome images, single and clustered chromosomes must be identified. Herein, we propose a feature-based method for distinguishing between single chromosomes and clustered chromosome. Method: The proposed method comprises three main steps. In the first step, chromosome objects are segmented from metaphase chromosome images in advance. In the second step, seven features are extracted from each segmented object, i.e., the normalized area, area/boundary ratio, side branch index, exhaustive thresholding index, normalized minimum width, minimum concave angle, and maximum boundary shift. Finally, the segmented objects are classified as a single chromosome or chromosome cluster using a combination of the seven features. Results: In total, 43,391 segmented objects, including 39,892 single chromosomes and 3,499 chromosome clusters, are used to evaluate the proposed method. The results show that the proposed method achieves an accuracy of 98.92% by combining the seven features using support vector machine. Conclusions: The proposed method is highly effective in distinguishing between single and clustered chromosomes and can be used as a preprocessing procedure for automated chromosome image analysis.

2.
AJNR Am J Neuroradiol ; 42(9): 1591-1597, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34167960

RESUMEN

BACKGROUND AND PURPOSE: The reliability of contrast-enhanced MRA in monitoring serial volumetric changes of unruptured intracranial aneurysms has not been established. We aimed to determine the coefficient of variance of contrast-enhanced MRA in measuring aneurysm volumes, thus establishing criteria for aneurysm growth and permitting identification of variables predictive of growth. MATERIALS AND METHODS: Aneurysm volumes were measured from serial contrast-enhanced MRA studies of patients with untreated intracranial aneurysms who underwent >2 sequential MR imaging evaluations. After coregistering all sequential studies in 3D space for each aneurysm and signal intensity normalization, aneurysm volume was determined across all time points. A linear mixed effects model was built to estimate the coefficient of variance of the measurement as well as to determine predictive variables. Growth was defined as relative growth exceeding 2 times the measurement coefficient of variance (sudden growth, as 4 times the coefficient of variance). RESULTS: A total of 95 patients with 112 aneurysms were included (5.9 scans during 4.0 years on average, 616 scan measurements in total). The coefficient of variance was 5.5% of the aneurysm volume, and the relative growth rate was dependent on the location: anterior cerebral artery, 4.52% per year; vertebral artery, 2.46% per year; middle cerebral artery, 2.74% per year; basilar artery, 2.36% per year; internal carotid artery, 1.14% per year. Thirty-six of 112 (32%) aneurysms were characterized as growing, and 11/36 of them had an episode of sudden growth. CONCLUSIONS: Volume measurement of unruptured intracranial aneurysms by contrast-enhanced MRA seems a reliable metric for tracking the growth trajectory of aneurysms. Furthermore, the aneurysm growth rate differs among different locations.


Asunto(s)
Aneurisma Intracraneal , Arteria Carótida Interna , Humanos , Aneurisma Intracraneal/diagnóstico por imagen , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética , Reproducibilidad de los Resultados
3.
AJNR Am J Neuroradiol ; 40(5): 849-854, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31023664

RESUMEN

BACKGROUND AND PURPOSE: Idiopathic intracranial hypertension is commonly associated with transverse sinus stenosis, a venous cause of pulsatile tinnitus. In patients with idiopathic intracranial hypertension, CSF drainage via lumbar puncture decreases intracranial pressure, which relieves the stenosis, and may provide at least temporary cessation of pulsatile tinnitus. The objective of this study was to evaluate changes in venous blood flow caused by lowered intracranial pressure in patients with pulsatile tinnitus to help identify the cause of pulsatile tinnitus. MATERIALS AND METHODS: Ten patients with suspected transverse sinus stenosis as a venous etiology for pulsatile tinnitus symptoms underwent MR imaging before and after lumbar puncture in the same session. The protocol included flow assessment and rating of pulsatile tinnitus intensity before and after lumbar puncture and MR venography before lumbar puncture. Post-lumbar puncture MR venography was performed in 1 subject. RESULTS: There was a lumbar puncture-induced reduction in venous peak velocity that correlated with the opening pressure (r = -0.72, P = .019) without a concomitant reduction in flow rate. Patients with flow jets had their peak velocity reduced by 0.30 ± 0.18 m/s (P = .002), correlating with a reduction in CSF pressure (r = 0.82, P = .024) and the reduction in subjectively scored pulsatile tinnitus intensity (r = 0.78, P = .023). The post-lumbar puncture MR venography demonstrated alleviation of the stenosis. CONCLUSIONS: Our results show a lumbar puncture-induced reduction in venous peak velocity without a concomitant reduction in flow rate. We hypothesize that the reduction is caused by the expansion of the stenosis after lumbar puncture. Our results further show a correlation between the peak velocity and pulsatile tinnitus intensity, suggesting the flow jet to be instrumental in the development of sound.


Asunto(s)
Circulación Cerebrovascular/fisiología , Hemodinámica/fisiología , Punción Espinal , Acúfeno/fisiopatología , Acúfeno/cirugía , Adulto , Constricción Patológica/complicaciones , Constricción Patológica/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Seudotumor Cerebral/complicaciones , Seudotumor Cerebral/fisiopatología , Seudotumor Cerebral/cirugía , Punción Espinal/métodos , Acúfeno/etiología , Senos Transversos/patología , Senos Transversos/fisiopatología
4.
AJNR Am J Neuroradiol ; 39(11): 2108-2113, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30309843

RESUMEN

BACKGROUND AND PURPOSE: Case reports demonstrate that coiling of a sigmoid sinus diverticulum can treat pulsatile tinnitus. We hypothesized that MR imaging 4D flow and computational fluid dynamics would reveal distinct blood flow patterns in the venous outflow tract in these patients. MATERIALS AND METHODS: Patients with pulsatile tinnitus of suspected venous etiology underwent MR imaging at 3T, using venous phase contrast-enhanced MR angiography, 4D flow, and 2D phase contrast. The contrast-enhanced MRA contours were evaluated to determine the presence and extent of a sigmoid sinus diverticulum. Computational fluid dynamics analysis was performed using the 4D flow inlet flow and the luminal contours from contrast-enhanced MRA as boundary conditions. In addition, computational fluid dynamics was performed for the expected post treatment conditions by smoothing the venous geometry to exclude the sigmoid sinus diverticulum from the anatomic boundary conditions. Streamlines were generated from the 4D flow and computational fluid dynamics velocity maps, and flow patterns were examined for the presence of rotational components. RESULTS: Twenty-five patients with pulsatile tinnitus of suspected venous etiology and 10 control subjects were enrolled. Five (20%) of the symptomatic subjects had sigmoid sinus diverticula, all associated with an upstream stenosis. In each of these patients, but none of the controls, a stenosis-related flow jet was directed toward the opening of the sigmoid sinus diverticulum with rotational flow patterns in the sigmoid sinus diverticulum and parent sigmoid sinus on both 4D flow and computational fluid dynamics. CONCLUSIONS: Consistent patterns of blood flow can be visualized in a sigmoid sinus diverticulum and the parent sinus using 4D flow and computational fluid dynamics. Strong components of rotational blood flow were seen in subjects with sigmoid sinus diverticula that were absent in controls.


Asunto(s)
Circulación Cerebrovascular/fisiología , Senos Craneales/fisiopatología , Divertículo/fisiopatología , Acúfeno/etiología , Adulto , Anciano , Senos Craneales/diagnóstico por imagen , Divertículo/diagnóstico por imagen , Femenino , Hemodinámica , Humanos , Hidrodinámica , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad
5.
Comput Methods Programs Biomed ; 154: 79-88, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29249349

RESUMEN

BACKGROUND AND OBJECTIVE: Flatfeet can be evaluated by measuring the calcaneal-fifth metatarsal angle on a weight-bearing lateral foot radiograph. This study aimed to develop an automated method for determining the calcaneal-fifth metatarsal angle on weight-bearing lateral foot radiograph. METHOD: The proposed method comprises four processing steps: (1) identification of the regions including the calcaneus and fifth metatarsal bones in a foot image; (2) delineation of the contours of the calcaneus and the fifth metatarsal; (3) determination of the tangential lines of the two bones from the contours; and (4) determination of the calcaneal-fifth metatarsal angle between the two tangential lines as arch angle. RESULTS: The proposed method was evaluated using 300 weight-bearing lateral foot radiographs. The arch angles determined by the proposed method were compared with those measured by a radiologist, and the errors between the automatically and manually determined angles were used to evaluate the precision of the method. The average error in the proposed method was found to be 1.12°â€¯±â€¯1.57° In the study, in 73.33% of the cases, the arch angles could be determined automatically without redrawing any tangential lines; in 23.00% of the cases, the angles would be correctly determined by redrawing one of the tangential lines; further, in only 3.67% of the cases, both the calcaneal and fifth metatarsal tangential lines needed to be redrawn to determine the arch angles. CONCLUSION: The results revealed that the proposed method has potential for assisting doctors in measuring the arch angles on weight-bearing lateral foot radiographs more efficiently.


Asunto(s)
Automatización , Calcáneo/diagnóstico por imagen , Pie Plano/diagnóstico por imagen , Pie/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Metatarso/diagnóstico por imagen , Soporte de Peso , Calcáneo/patología , Pie Plano/patología , Pie/patología , Humanos , Metatarso/patología , Radiografía , Reproducibilidad de los Resultados
7.
J Neuroimaging ; 25(6): 892-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25753738

RESUMEN

Eddy current distortion is an important issue that may influence the quantitative measurements of diffusion tensor imaging (DTI). The corrections of eddy current artifacts could be performed using bipolar diffusion gradients or unipolar gradients with affine registration. Whether the diffusion pulse sequence affects the quantification of DTI indices and the technique that produces more reliable DTI indices in terms of reproducibility both remain unclear. Therefore, the purpose of this study was to compare the reproducibility and mean values of DTI-derived indices between unipolar and bipolar diffusion pulse sequences based on actual human brain data. Five repeated datasets of unipolar and bipolar DTI were acquired from 10 healthy subjects at different echo times (TEs). The reproducibility and mean values of DTI indices were assessed by calculating the coefficient of variation and mean values of the 5 repeated measurements. The results revealed that the reproducibility and mean values of DTI indices were significantly affected by the pulse sequence. Unipolar DTI exhibited significantly higher reproducibility than bipolar DTI even at the same TE, and the mean values of DTI indices were significantly different between them. Therefore, we concluded that the reproducibility and mean values of DTI indices were significantly influenced by diffusion pulse sequences.


Asunto(s)
Encéfalo/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Imagen de Difusión Tensora/métodos , Aumento de la Imagen/métodos , Anisotropía , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Adulto Joven
8.
Comput Methods Programs Biomed ; 118(1): 1-10, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25467807

RESUMEN

The aim of this study was to develop an automated method for the detection of endotracheal tube and location of its tip in paediatric chest radiographs. In this method, a seed point was first determined from the line crossing the cervical region and a line path was traced from the seed point. Two features, Lmax and C, were determined from the path and were combined to detect the existence of the endotracheal tube. Multiple thresholds applied to the line path were used to determine the candidate locations for the tip, and the most suitable location was selected from these candidates by analysing the image features. To evaluate the performance of detection of endotracheal tube existence, support vector machine was used to classify the images with and without endotracheal tubes on the basis of Lmax and C. The discriminant performance of the method was evaluated using receiver operating characteristic (ROC) analysis. To evaluate the precision of the detected tip locations, the tip locations in paediatric chest images were annotated by a radiologist. The distance (error) between the detected and annotated locations was used to evaluate detection precision for the tip location. The proposed method was evaluated using 528 images with endotracheal tubes and 816 images without endotracheal tubes. The discriminant performance in this study, evaluated as Az (area under the ROC curve), for detecting the existence of endotracheal tubes on the basis of the two features was 0.943±0.009, and the detection error of the tip location was 1.89±2.01mm. The proposed method obtained high performance results and could be useful for detecting the malposition of endotracheal tubes in paediatric chest radiographs.


Asunto(s)
Intubación Intratraqueal/instrumentación , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica , Niño , Humanos , Intubación Intratraqueal/efectos adversos , Reconocimiento de Normas Patrones Automatizadas/métodos , Valor Predictivo de las Pruebas
9.
Acta Radiol ; 56(6): 696-701, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24948788

RESUMEN

BACKGROUND: The ability to give high priority to examinations with pathological findings could be very useful to radiologists with large work lists who wish to first evaluate the most critical studies. A computer-aided detection (CAD) system for identifying chest examinations with abnormalities has therefore been developed. PURPOSE: To evaluate the effectiveness of a CAD system on report turnaround times of chest examinations with abnormalities. MATERIAL AND METHODS: The CAD system was designed to automatically mark chest examinations with possible abnormalities in the work list of radiologists interpreting chest examinations. The system evaluation was performed in two phases: two radiologists interpreted the chest examinations without CAD in phase 1 and with CAD in phase 2. The time information recorded by the radiology information system was then used to calculate the turnaround times. All chest examinations were reviewed by two other radiologists and were divided into normal and abnormal groups. The turnaround times for the examinations with pathological findings with and without the CAD system assistance were compared. RESULTS: The sensitivity and specificity of the CAD for chest abnormalities were 0.790 and 0.697, respectively, and use of the CAD system decreased the turnaround time for chest examinations with abnormalities by 44%. CONCLUSION: The turnaround times required for radiologists to identify chest examinations with abnormalities could be reduced by using the CAD system. This system could be useful for radiologists with large work lists who wish to first evaluate the most critical studies.


Asunto(s)
Interpretación de Imagen Radiográfica Asistida por Computador , Radiografía Torácica/métodos , Humanos , Sistemas de Información Radiológica , Factores de Tiempo
10.
Comput Methods Programs Biomed ; 117(2): 92-103, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25168776

RESUMEN

This study developed a computerised method for fovea centre detection in fundus images. In the method, the centre of the optic disc was localised first by the template matching method, the disc-fovea axis (a line connecting the optic disc centre and the fovea) was then determined by searching the vessel-free region, and finally the fovea centre was detected by matching the fovea template around the centre of the axis. Adaptive Gaussian templates were used to localise the centres of the optic disc and fovea for the images with different resolutions. The proposed method was evaluated using three publicly available databases (DIARETDB0, DIARETDB1 and MESSIDOR), which consisted of a total of 1419 fundus images with different resolutions. The proposed method obtained the fovea detection accuracies of 93.1%, 92.1% and 97.8% for the DIARETDB0, DIARETDB1 and MESSIDOR databases, respectively. The overall accuracy of the proposed method was 97.0% in this study.


Asunto(s)
Algoritmos , Angiografía con Fluoresceína/métodos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Retina/anatomía & histología , Inteligencia Artificial , Interpretación Estadística de Datos , Fondo de Ojo , Humanos , Distribución Normal , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
11.
PLoS One ; 9(6): e98826, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24915461

RESUMEN

Microarrays based on gene expression profiles (GEPs) can be tailored specifically for a variety of topics to provide a precise and efficient means with which to discover hidden information. This study proposes a novel means of employing existing GEPs to reveal hidden relationships among diseases, genes, and drugs within a rich biomedical database, PubMed. Unlike the co-occurrence method, which considers only the appearance of keywords, the proposed method also takes into account negative relationships and non-relationships among keywords, the importance of which has been demonstrated in previous studies. Three scenarios were conducted to verify the efficacy of the proposed method. In Scenario 1, disease and drug GEPs (disease: lymphoma cancer, lymph node cancer, and drug: cyclophosphamide) were used to obtain lists of disease- and drug-related genes. Fifteen hidden connections were identified between the diseases and the drug. In Scenario 2, we adopted different diseases and drug GEPs (disease: AML-ALL dataset and drug: Gefitinib) to obtain lists of important diseases and drug-related genes. In this case, ten hidden connections were identified. In Scenario 3, we obtained a list of disease-related genes from the disease-related GEP (liver cancer) and the drug (Capecitabine) on the PharmGKB website, resulting in twenty-two hidden connections. Experimental results demonstrate the efficacy of the proposed method in uncovering hidden connections among diseases, genes, and drugs. Following implementation of the weight function in the proposed method, a large number of the documents obtained in each of the scenarios were judged to be related: 834 of 4028 documents, 789 of 1216 documents, and 1928 of 3791 documents in Scenarios 1, 2, and 3, respectively. The negative-term filtering scheme also uncovered a large number of negative relationships as well as non-relationships among these connections: 97 of 834, 38 of 789, and 202 of 1928 in Scenarios 1, 2, and 3, respectively.


Asunto(s)
Descubrimiento de Drogas , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Estudios de Asociación Genética , Animales , Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , Humanos , Modelos Biológicos , Curva ROC , Reproducibilidad de los Resultados
12.
Acad Radiol ; 20(8): 1024-31, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23830608

RESUMEN

RATIONALE AND OBJECTIVES: The aim of this study was to develop a computerized scheme for automated identity recognition based on chest radiograph features. MATERIALS AND METHODS: The proposed method was evaluated on a database consisting of 1000 pairs of posteroanterior chest radiographs. The method was based on six features: length of the lung field, size of the heart, area of the body, and widths of the upper, middle, and lower thoracic cage. The values for the six features were determined from a chest image, and absolute differences in feature values between the two images (feature errors) were used as indices of image similarity. The performance of the proposed method was evaluated by receiver operating characteristic (ROC) analysis. The discriminant performance was evaluated as the area Az under the ROC curve. RESULTS: The discriminant performance Az of the feature errors for lung field length, heart size, body area, upper cage width, middle cage width, and lower cage width were 0.794 ± 0.005, 0.737 ± 0.007, 0.820 ± 0.008, 0.860 ± 0.005, 0.894 ± 0.006, and 0.873 ± 0.006, respectively. The combination of the six feature errors obtained an Az value of 0.963 ± 0.002. CONCLUSION: The results indicate that combining the six features yields a high discriminant performance in recognizing patient identity. The method has potential usefulness for automated identity recognition to ensure that chest radiographs are associated with the correct patient.


Asunto(s)
Algoritmos , Sistemas de Identificación de Pacientes/métodos , Sistemas de Identificación de Pacientes/estadística & datos numéricos , Reconocimiento de Normas Patrones Automatizadas/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica/métodos , Radiografía Torácica/estadística & datos numéricos , Adolescente , Adulto , Anciano , Inteligencia Artificial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sistemas de Información Radiológica/estadística & datos numéricos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
13.
AJNR Am J Neuroradiol ; 34(10): 1945-51, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23788598

RESUMEN

BACKGROUND AND PURPOSE: ESRD results in excessive accumulation of urea and toxic metabolites. Hemodialysis is usually performed to maintain health in patients with ESRD; however, it may cause silent white matter alterations in the earlier stages. Hence, this study aimed to perform voxelwise diffusion tensor analysis for global detection of subtle white matter alterations in patients with ESRD. MATERIALS AND METHODS: Twenty-eight patients with ESRD and 25 age-matched control subjects were enrolled in this study. Each subject underwent CASI assessment and DTI. After spatial normalization of DTI images, voxelwise statistical analyses were performed to compare DTI parameters between the 2 groups. RESULTS: In patients with ESRD, AD, RD, and MD values were significantly increased, whereas the FA value was significantly decreased, mostly in the corpus callosum, bilateral sagittal stratum, and pons. Multiple regression analysis further revealed that both RD and MD were positively correlated with the duration of hemodialysis in the pons; however, no significant correlation was observed with FA. Negative correlations of RD and MD and a positive correlation of FA with the CASI score were observed in the corona radiata. CONCLUSIONS: We concluded that voxelwise DTI analysis is helpful in the detection of white matter alterations caused by hemodialysis.


Asunto(s)
Cuerpo Calloso/patología , Imagen de Difusión Tensora/métodos , Fallo Renal Crónico/terapia , Leucoencefalopatías/etiología , Leucoencefalopatías/patología , Diálisis Renal/efectos adversos , Adulto , Anisotropía , Encéfalo/patología , Edema Encefálico/etiología , Edema Encefálico/patología , Femenino , Humanos , Fallo Renal Crónico/complicaciones , Masculino , Persona de Mediana Edad , Fibras Nerviosas Mielínicas/patología
14.
Br J Radiol ; 86(1025): 20120270, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23520227

RESUMEN

OBJECTIVE: Determine values of pathological analysis of the canister content during a vacuum-assisted breast biopsy (VABB). METHODS: Approval was obtained from the ethical committee. Prospective radiological and pathological analyses of the canister content collected during 231 VABBs performed on 231 patients were carried out. χ(2) test was used to determine predictors on canister pathology. RESULTS: The canister pathology was reported separately in 212 cases. It showed only blood in 78/212 (37%) cases and benign (including high-risk lesions) and malignant results in, respectively, 113/212 (53%) and 21/212 (10%) cases. Respective specimen analysis was benign, including high-risk lesions in 162/212 cases (76%) and malignant in 50/212 (24%) cases. Microcalcifications were documented on canister X-ray in 70/231 (30%) cases. There was significant association between the canister and the specimen pathology (p<0.0001). In none of the cases was microcalcifications seen exclusively in the canister content or pathological upgrading found in the canister content compared with the specimen. CONCLUSION: Small tissue fragments and microcalcifications may be lost in the canister during a VABB. Nevertheless, our results did not show any significant value for systematic analysis of the canister content. ADVANCES IN KNOWLEDGE: There is no added diagnostic value to retrieval and analysis of tissue lost in the canister during a VABB.


Asunto(s)
Enfermedades de la Mama/patología , Mama/patología , Técnicas Estereotáxicas/instrumentación , Biopsia con Aguja/instrumentación , Biopsia con Aguja/métodos , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Vacio
15.
Phys Med Biol ; 56(24): 7737-53, 2011 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-22094308

RESUMEN

A computerized scheme was developed for automated identification of erect posteroanterior (PA) and supine anteroposterior (AP) chest radiographs. The method was based on three features, the tilt angle of the scapula superior border, the tilt angle of the clavicle and the extent of radiolucence in lung fields, to identify the view of a chest radiograph. The three indices A(scapula), A(clavicle) and C(lung) were determined from a chest image for the three features. Linear discriminant analysis was used to classify PA and AP chest images based on the three indices. The performance of the method was evaluated by receiver operating characteristic analysis. The proposed method was evaluated using a database of 600 PA and 600 AP chest radiographs. The discriminant performances Az of A(scapula), A(clavicle) and C(lung) were 0.878 ± 0.010, 0.683 ± 0.015 and 0.962 ± 0.006, respectively. The combination of the three indices obtained an Az value of 0.979 ± 0.004. The results indicate that the combination of the three indices could yield high discriminant performance. The proposed method could provide radiologists with information about the view of chest radiographs for interpretation or could be used as a preprocessing step for analyzing chest images.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Radiografía Torácica/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Automatización , Análisis Discriminante , Femenino , Humanos , Pulmón/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Posición Supina , Adulto Joven
16.
Med Phys ; 38(7): 4241-50, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21859026

RESUMEN

PURPOSE: The aim of this study was to develop an automated method for detection of local texture-based and density-based abnormalities in chest radiographs. METHODS: The method was based on profile analysis to detect abnormalities in chest radiographs. In the method, one density-based feature, Density Symmetry Index, and two texture-based features, Roughness Maximum Index and Roughness Symmetry Index, were used to detect abnormalities in the lung fields. In each chest radiograph, the lung fields were divided into four zones initially and then the method was applied to each zone separately. For each zone, Density Symmetry Index was obtained from the projection profile of each zone, and Roughness Maximum Index and Roughness Symmetry Index were obtained by measuring the roughness of the horizontal profiles via moving average technique. Linear discriminant analysis was used to classify normal and abnormal cases based on the three indices. The discriminant performance of the method was evaluated using ROC analysis. RESULTS: The method was evaluated on a database of 250 normal and 250 abnormal chest images. In the optimized conditions, the zone-based performance Az of the method for zones 1, 2, 3, and 4 were 0.917, 0.897, 0.892, and 0.814, respectively, and the case-based performance Az of the method was 0.842. Our previous method for detection of gross abnormalities was also evaluated on the same database. The case-based performance of our previous method was 0.689. CONCLUSIONS: In comparing the previous method and the new method proposed in this study, there was a great improvement by the new method for detection of local texture-based and density-based abnormalities. The new method combined with the previous one has potential for screening abnormalities in chest radiographs.


Asunto(s)
Algoritmos , Enfermedades Pulmonares/diagnóstico por imagen , Reconocimiento de Normas Patrones Automatizadas/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica/métodos , Humanos , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Clin Radiol ; 64(6): 628-36, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19414087

RESUMEN

AIM: To present the sonographic findings of mammographically non-calcified ductal carcinoma in situ (DCIS) with histopathologic correlation. MATERIALS AND METHODS: The mammographic and ultrasonographic presentations of 47 radiographically non-calcified DCIS lesions in 35 patients were retrospectively analysed. Histological characteristics (architectural appearance, nuclear grade, percent of involved lobules, and presence of necrosis) were reviewed. RESULTS: Seventeen lesions were not mammographically visible (17/47, 36%). Ultrasonographically, these lesions showed an irregular shape (28/47, 60%), microlobulated margins (34/47, 72%) and abrupt interfaces (42/47, 90%). Only 11% (5/47) displayed posterior shadowing. The echotexture of these lesions was most frequently complex (29/47, 62%); therefore, they were divided into two types: type I (24 cases), which were predominantly solid with cystic components, and type II (five cases), which were predominantly cystic with a solid intra-cystic component. A trend to have greater than 50% DCIS cells in cancerous lobules was observed in masses displaying type I echotexture (difference=36%, 95% confidence interval 10.6-62.5) and microlobulated margins (difference=32%, 95% confidence interval 5.1-58.7). CONCLUSION: Ultrasonographically detected radiographically non-calcified DCIS commonly displays an irregular shape, microlobulated margins, and complex echotexture, giving a "pseudomicrocystic" appearance. Microlobulated margins and "pseudomicrocystic" echotexture seem to be associated with a cancerization of the lobules.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Carcinoma Intraductal no Infiltrante/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Calcinosis/patología , Carcinoma Intraductal no Infiltrante/patología , Detección Precoz del Cáncer , Femenino , Humanos , Mamografía/métodos , Persona de Mediana Edad , Estudios Retrospectivos , Ultrasonografía Mamaria/métodos
18.
Thorac Cardiovasc Surg ; 55(7): 450-3, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18027471

RESUMEN

BACKGROUND: The occurrence of complications after major pulmonary resection is known to be related to various factors. However, peri-surgical injuries to the ipsilateral non-diseased lobes(s) occurring during resection have never been mentioned in the literature. This study aimed to verify the injury in cases after lobectomy and wedge resection. METHODS: Data from eighteen patients who underwent lobectomy or wedge resection for malignant tumor between January 2003 and January 2004 were collected. All patients had pre- and postoperative examinations of alveolar-capillary membrane (A/C) permeability using 99m TC-DPTA radioaerosol. RESULTS: Ten lobectomies and eight wedge resection were performed. Using the paired t-test with each patient's pre-operative A/C permeability as his own control data, the postoperative A/C permeability of the ipsilateral non-diseased lobe(s) was found to be significantly increased. The degree of increase in the lobectomy group was the same as that in the wedge resection group. However, no significant change was found on the contralateral side in both groups. CONCLUSION: The degree of increase of permeability was the same in both groups, indicating that the effects of stretch on the surviving lung are not a contributing factor to the change in A/C permeability. The mechanical injuries during the pulmonary surgical procedure alter the permeability, which could be a possible factor causing postoperative pulmonary complications.


Asunto(s)
Barrera Alveolocapilar/lesiones , Permeabilidad Capilar , Enfermedades Pulmonares/etiología , Lesión Pulmonar , Neoplasias Pulmonares/cirugía , Neumonectomía/efectos adversos , Administración por Inhalación , Adulto , Aerosoles , Anciano , Barrera Alveolocapilar/diagnóstico por imagen , Barrera Alveolocapilar/metabolismo , Femenino , Humanos , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Pulmón/cirugía , Enfermedades Pulmonares/diagnóstico por imagen , Enfermedades Pulmonares/metabolismo , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/metabolismo , Masculino , Persona de Mediana Edad , Neumonectomía/métodos , Cintigrafía , Radiofármacos/administración & dosificación , Estrés Mecánico , Pentetato de Tecnecio Tc 99m/administración & dosificación , Resultado del Tratamiento
19.
Surg Endosc ; 20(11): 1749-53, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17024534

RESUMEN

BACKGROUND: Compensatory hyperhidrosis is the most troublesome side effect and the leading cause of regret with sympathetic surgery. A new classification is proposed to make the procedure more selective and to minimize the side effects and regret rate. Also, a proposed mechanism for compensatory hyperhidrosis is discussed. METHODS: Between January 2002 and July 2003, 464 patients with various sympathetic disorders underwent thoracoscopic sympathectomy/sympathicotomy (ETS) or sympathetic block by clipping (ESB) at various levels according to the authors' classification. The surgery was performed on an outpatient basis. The rates of success, compensatory hyperhidrosis, and regret were recorded. RESULTS: All the patients were followed up for 17 to 35 months. All excessive sweating was effectively stopped to varying degrees. The 25 patients with palmar hyperhidrosis who insisted on receiving ETS of T4 experienced no compensatory hyperhidrosis. Of the 54 patients with facial blushing who received ESB of T2, 23 experienced compensatory hyperhidrosis. Nine patients expressed regret and requested removal of the clips. Of the 33 patients with craniofacial hyperhidrosis who received ESB of T3, 9 experienced compensatory hyperhidrosis. Three expressed regret, and reverse procedures were performed. For 324 patients with palmar hyperhidrosis receiving ESB of T4, no compensatory hyperhidrosis was found. Only two expressed regret because of discomfort. No compensatory hyperhidrosis or regret was noted with 28 patients who received ESB of T5 for axillary sweating. There was no recurrence in the entire series. CONCLUSIONS: Different procedures are recommended for different sympathetic disorders according to the classification. The higher the level of sympathetic ganglion blockade, the higher is the regret rate. Therefore, for T2 and T3 ganglion, endoscopic thoracic sympathetic block by the clipping method is strongly recommended because of its reversibility.


Asunto(s)
Hiperhidrosis/clasificación , Hiperhidrosis/etiología , Simpatectomía/efectos adversos , Simpatectomía/métodos , Adulto , Procedimientos Quirúrgicos Ambulatorios , Femenino , Humanos , Hiperhidrosis/fisiopatología , Hiperhidrosis/cirugía , Masculino , Satisfacción del Paciente , Reoperación , Toracoscopía , Resultado del Tratamiento
20.
J Clin Pharm Ther ; 31(4): 363-8, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16882106

RESUMEN

BACKGROUND AND OBJECTIVE: Glucocorticosteroid reversibility-testing is undertaken over a period of 3 months to identify whether patients with chronic obstructive pulmonary disease (COPD) would benefit from long-term inhaled corticosteroids. This study assessed whether alveolar-capillary membrane (a/c) permeability testing can be used as an early alternative test method for the same purpose. METHODS: Fourteen patients with severe and symptomatic moderate COPD (group S) were prescribed inhaled steroid 800 microg/day for 3 months. Before inhalation and 4 weeks after inhalation therapy, forced expiratory volume in 1 s (FEV(1)) and a/c permeability using (99m)Tc-DTPA were performed. FEV(1) was recorded again at the end of the third month. Another 10 patients with COPD of comparable severity (group B) prescribed with inhaled bronchodilators were examined and studied as controls. RESULTS: In group S, the permeability decreased in eight patients (group D) and increased in six patients (group I). No significant change was noted in FEV(1) at the end of the first month. However, seven patients in group D showed significant improvement in FEV(1) at the end of the third month, whereas in patients in group I no significant changes were observed. In group B, no significant change in a/c permeability was observed, although the FEV(1) increased by 12-17%. CONCLUSION: With steroid inhalation, the a/c permeability at 4 weeks predicts future changes in lung functions. Long-term inhaled corticosteroids are likely to be useful if permeability decreases. This test, which needs further validation, appears to provide much earlier prediction of response than glucocorticoid reversibility testing.


Asunto(s)
Corticoesteroides/uso terapéutico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Administración por Inhalación , Corticoesteroides/administración & dosificación , Corticoesteroides/farmacología , Anciano , Broncodilatadores/farmacología , Broncodilatadores/uso terapéutico , Estudios de Casos y Controles , Permeabilidad de la Membrana Celular/efectos de los fármacos , Femenino , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Pulmonar Obstructiva Crónica/clasificación , Índice de Severidad de la Enfermedad
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