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2.
Radiol Clin North Am ; 58(6): 1071-1083, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33040849

RESUMO

Primary hyperparathyroidism (PHPT) is a common endocrine abnormality, caused in most cases by a single parathyroid adenoma. Surgery remains the first-line curative therapy in PHPT. Imaging plays a vital role in presurgical localization of parathyroid adenomas. Ultrasound provides a safe and quick imaging modality free of ionizing radiation, but is operator dependent. Sestamibi scan offers comparable sensitivity to ultrasound, improved with concurrent tomographic imaging. 4DCT remains a problem-solving technique in challenging cases and after failed neck exploration. We present an overview of various parathyroid imaging modalities, including protocols and findings, in addition to relevant pearls and pitfalls.


Assuntos
Hiperparatireoidismo Primário/diagnóstico por imagem , Imageamento Tridimensional , Neoplasias das Paratireoides/complicações , Neoplasias das Paratireoides/diagnóstico por imagem , Intensificação de Imagem Radiográfica , Tomografia Computadorizada por Raios X/métodos , Diagnóstico por Imagem/métodos , Feminino , Humanos , Hiperparatireoidismo Primário/etiologia , Masculino , Glândulas Paratireoides/diagnóstico por imagem , Glândulas Paratireoides/patologia , Glândulas Paratireoides/cirurgia , Neoplasias das Paratireoides/patologia , Neoplasias das Paratireoides/cirurgia , Paratireoidectomia/métodos , Prognóstico , Compostos Radiofarmacêuticos , Resultado do Tratamento , Ultrassonografia Doppler/métodos
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2190-2193, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018441

RESUMO

Digital radiography has been increasingly adopted since it can provide better image quality compared to conventional screen/film method. However, digital radiography can sometimes produce low-quality images because its processing algorithm is unaware of the content. Here, an adaptive multi-scale image enhancement algorithm for digital radiography is demonstrated. The algorithm adapts to the context of the image, thus providing better image quality. The qualitative and quantitative validations of the algorithm in phantoms and in clinical settings showed satisfactory performance.


Assuntos
Aumento da Imagem , Intensificação de Imagem Radiográfica , Algoritmos , Imagens de Fantasmas
4.
Medicine (Baltimore) ; 99(37): e22097, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32925753

RESUMO

This study aimed to improve the diagnostic accuracy of breast diseases by combining breast imaging-reporting and data system (BI-RADS) with the enhancement intensity and pattern of contrast-enhanced spectral mammography (CESM) (this combination of BI-RADS and CESM was designated as BaC).BI-RADS was used to evaluate low-energy CESM images. Spearman nonparametric correlation analysis was performed to analyze the correlation between the enhancement intensity of CESM subtraction images and the pathological results. Odds ratio (OR) values were calculated to determine whether the enhancement pattern of CESM subtraction images is a risk factor for benign and malignant lesions. The diagnostic efficacies of BI-RADS, CESM, and BaC scores for benign and malignant breast diseases were analyzed using the receiver operating characteristic (ROC) curve.Lesions with a high enhancement intensity were more likely to be malignant than those with low enhancement intensity. Lesions with heterogeneous enhancement tended to be malignant, whereas those with homogeneous enhancement tended to be benign. No significant correlation was observed between ring enhancement and the benignity or malignancy of lesions. The area under the ROC curve of BaC was higher than that of BI-RADS or CESM, and the difference was statistically significant.The diagnostic efficacy of BI-RADS combined with CESM enhancement was superior to that of either method alone.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Mamografia , Intensificação de Imagem Radiográfica , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Estudos Retrospectivos , Adulto Jovem
5.
J Comput Assist Tomogr ; 44(5): 772-779, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936579

RESUMO

OBJECTIVE: To create a map of iodine densities within affected segments of small-bowel Crohn disease (CD) derived from contrast-enhanced dual-energy computed tomography enterography (DECTE) studies. METHODS: Twenty CD patients imaged with intravenous contrast-enhanced DECTE between June 2016 and December 2017 were retrospectively identified. Ten patients without clinical evidence of CD and 8 normal-appearing jejunal segments in CD patients were controls. Using prototype software, 8 manual contours were drawn along the mucosa of affected segments. Relatively normal-appearing bowel was included at the edges. These contours served as a basis for iodine density calculation and 3-dimensional iodine density map rendering. Color-coded iodine densities allowed detection and quantification of the most and least dense portion of each segment and also permitted relative comparison between segments. RESULTS: The average iodine density per CD involved segment ranged 1.0 to 3.3 mg/mL, which differed significantly from normal ileum (P < 0.0001) and normal-appearing jejunum in patients with CD (P = 0.0009). Standard deviations ranged from 0.8 to 1.7 mg/mL, which differed significantly from normal ileum (P = 0.0039) and normal-appearing jejunum in patients with CD (P = 0.0056). The amplitude of the power spectrum ranged from 0.66 to 3.3 demonstrating patches of iodine rather than uniform distribution. This differed significantly from normal ileum (P = 0.0005) and normal-appearing jejunum in patients with CD (P = 0.0004). CONCLUSIONS: Heterogeneous CD activity and distribution can be displayed as iodine density maps created from DECTE.


Assuntos
Meios de Contraste/farmacocinética , Doença de Crohn/diagnóstico por imagem , Imageamento Tridimensional/métodos , Iodo/farmacocinética , Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Trato Gastrointestinal/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
6.
PLoS One ; 15(9): e0231431, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881876

RESUMO

OBJECTIVE: To compare the radiation dose and the objective and subjective image quality of 80 kVp and 80/150 kVp with tin filter (80/Sn150 kVp) computed tomography (CT) in oncology patients. METHODS: One-hundred-and-forty-five consecutive oncology patients who underwent third-generation dual-source dual-energy CT of the abdomen for evaluation of malignant visceral, peritoneal, extraperitoneal, and bone tumor were retrospectively recruited. Two radiologists independently reviewed each observation in 80 kVp CT and 80/Sn150 kVp CT. Modified line-density profile of the tumor and contrast-to-noise ratio (CNR) were measured. Diagnostic confidence, lesion conspicuity, and subjective image quality were calculated and compared between image sets. The effective dose and size-specific dose estimate (SSDE) were calculated in the image sets. RESULTS: Modified line-density profile analysis revealed higher attenuation differences between the tumor and normal tissue in 80 kVp CT than in 80/Sn150 kVp CT (127 vs. 107, P = 0.05). The 80 kVp CT showed increased CNR in the liver (8.0 vs. 7.6) and the aorta (18.9 vs. 16.3) than the 80/Sn150 kVp CT. The 80 kVp CT yielded higher enhancement of organs (4.9 ± 0.2 vs. 4.7 ± 0.4, P<0.001) and lesion conspicuity (4.9 ± 0.3 vs. 4.8 ± 0.5, P = 0.035) than the 80/Sn150 kVp CT; overall image quality and confidence index were comparable. The effective dose was reduced by 45.2% with 80 kVp CT (2.3 mSv ± 0.9) compared to 80/Sn150 kVp CT (4.1 mSv ± 1.5). The SSDE was 7.4 ± 3.8 mGy on 80/Sn150 kVp CT and 4.1 ± 2.2 mGy on 80 kVp CT. CONCLUSIONS: The 80 kVp CT reduced the radiation dose by 45.2% in oncology patients while showing comparable or superior image quality to that of 80/Sn150 kVp CT for abdominal tumor evaluation.


Assuntos
Neoplasias/diagnóstico por imagem , Doses de Radiação , Intensificação de Imagem Radiográfica/instrumentação , Estanho , Tomografia Computadorizada por Raios X/instrumentação , Abdome/diagnóstico por imagem , Idoso , Algoritmos , Meios de Contraste/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pelve/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
7.
Am J Case Rep ; 21: e926781, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32952147

RESUMO

BACKGROUND Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus, SARS-CoV-2, and is associated with severe respiratory disease. There are extensive publications on the chest computed tomography (CT) findings of COVID-19 pneumonia, with ground-glass opacities (GGO) and mixed GGO and consolidation being the most common findings. Those with interstitial thickening manifesting as reticular opacities typically show superimposed ground-glass opacities, giving a crazy-paving pattern. CASE REPORT We report the case of a 77-year-old man with a background of asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) who presented with progressive cough and shortness of breath for 2 days. He was in close contact with a confirmed COVID-19 case. Reverse-transcription polymerase chain reaction analysis of a nasopharyngeal swab was positive for SARS-CoV-2. The initial chest radiograph was negative for lung consolidation and ground-glass opacities. During admission, he had worsening shortness of breath with desaturation, prompting a chest CT examination, which was performed on day 14 of illness. The chest CT revealed an atypical finding of predominant focal subpleural interstitial thickening in the right lower lobe. He was provided supportive treatment along with steroid and antibiotics. He recovered well and subsequently tested negative for 2 consecutive swabs. He was discharged after 34 days. CONCLUSIONS Interstitial thickening or reticular pattern on CT has been described in COVID-19 pneumonia, but largely in association with ground-glass opacity or consolidation. This case demonstrates an atypical predominance of interstitial thickening on chest CT in COVID-19 pneumonia on day 14 of illness, which is the expected time of greatest severity of the disease.


Assuntos
Infecções por Coronavirus/diagnóstico , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Pneumonia Viral/diagnóstico , Intensificação de Imagem Radiográfica , Síndrome Respiratória Aguda Grave/diagnóstico por imagem , Corticosteroides/administração & dosagem , Idoso , Antibacterianos/administração & dosagem , Técnicas de Laboratório Clínico , Meios de Contraste , Infecções por Coronavirus/complicações , Tosse/diagnóstico , Tosse/etiologia , Progressão da Doença , Dispneia/diagnóstico , Dispneia/etiologia , Seguimentos , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/terapia , Masculino , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico por imagem , Medição de Risco , Síndrome Respiratória Aguda Grave/virologia , Resultado do Tratamento
8.
Clin Imaging ; 67: 226-236, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32871427

RESUMO

PURPOSE: Digital radiography has the potential to improve the practice of radiography but it also has the potential to significantly increase patient doses. Considering rapidly growing digital radiography in many centers, concerns rise about increasing the collective dose of the human population and following health effects. This study aimed to estimate organ and effective doses and calculate the lifetime attributable risk (LAR) of cancer incidence and mortality in digital radiography procedures in Iran. METHODS: Organ and effective doses of 12 routine digital radiography examinations including the skull, cervical spine, chest, thoracic spine, lumbar spine, pelvic and abdomen were estimated using PCXMC software based on Monte Carlo simulation method. Then, LARs of cancer incidence and mortality were estimated using the BEIR VII method. RESULTS: Organ doses ranged from 0.01 to a maximum of 2.5 mGy while effective doses ranged from 0.01 to 0.7 mSv. Radiation risk showed dependence on the X-ray examination type and the patient's sex and age. In skull and cervical X-rays, the thyroid; in the chest and thoracic spine X-rays, the lung, and breast; and in the lumbar spine, pelvic and abdominal X-rays, the colon and bladder had the highest LAR of cancer incidence and mortality. Furthermore, younger patients and also females were at higher radiation risk. CONCLUSION: The lifetime attributable risk of cancer incidence and mortality due to radiation exposure is not trivial. Therefore efforts should be made to reduce patient doses while maintaining image quality.


Assuntos
Neoplasias Induzidas por Radiação/epidemiologia , Abdome , Mama , Feminino , Humanos , Incidência , Masculino , Método de Monte Carlo , Pescoço , Neoplasias Induzidas por Radiação/etiologia , Pelve , Doses de Radiação , Intensificação de Imagem Radiográfica , Radiografia , Fatores de Risco , Software , Coluna Vertebral , Tórax
9.
Br J Radiol ; 93(1114): 20200565, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783630

RESUMO

OBJECTIVES: To investigate via computer simulation, an optimised tube voltage (kVp) range for caesium iodide (CsI)-based digital radiography (DR) of the abdomen, pelvis and lumbar spine. METHODS: Software capable of simulating abdomen, pelvis and spine radiographs was used. Five evaluators graded clinical image criteria in images of 20 patients at tube voltages ranging from 60 to 120 kVp in 10 kVp increments. These criteria were scored blindly against the same patient reconstructed at a specific reference kVp. Linear mixed effects analysis was used to evaluate image scores for each criterion and test for statistical significance. RESULTS: Score was dependent on tube voltage and image criteria; both were statistically significant. All criteria for all anatomies scored very poorly at 60 kVp. Scores for abdomen, pelvis and spine imaging peaked at 70, 70 and 100 kVp, respectively, but other kVp values were not significantly poorer. CONCLUSIONS: Results indicate optimum tube voltages of 70 kVp for abdomen and pelvis (with an optimum range 70-120 kVp), and 100 kVp (optimum range 80-120 kVp) for lumbar spine. ADVANCES IN KNOWLEDGE: There are no recommendations for optimised tube voltage parameters for DR abdomen, pelvis or lumbar spine imaging. This study has investigated and recommended an optimal tube voltage range.


Assuntos
Abdome/diagnóstico por imagem , Pelve/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Coluna Vertebral/diagnóstico por imagem , Algoritmos , Césio , Simulação por Computador , Humanos , Iodetos , Imagens de Fantasmas , Interpretação de Imagem Radiográfica Assistida por Computador , Software
10.
BMC Med Inform Decis Mak ; 20(1): 180, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32758220

RESUMO

BACKGROUND: User satisfaction with PACS is considered as one of the important criteria for assessing success in using PACS. The objective of this study was to determine the level of user satisfaction with PACS and to compare its functional features with traditional film-based systems. METHODS: This study was conducted in 2017. Residents at three large university hospitals in Kerman filled-out a self-administered questionnaire consisting of three parts: demographic information of participants, user satisfaction with PACS, comparing features of the two digital and traditional imaging systems. The validity of this questionnaire was approved by five medical informatics, radiology, and health information management specialists and its reliability was confirmed by Cronbach's alpha (86%). Data were analyzed using descriptive statistics and the Spearman, Mann Whitney U and Kruskal-Wallis statistical tests. RESULTS: The mean of the participants' ages was 31.4 (±4.4) years and 59% of the participants were females. The mean of physicians' satisfaction with PACS' had no significant relationship with their age (P = 0.611), experience of using PACS (P = 0.301), specialty (P = 0.093), and percent of interpretation of images with PACS (P = 0.762). It had a significant relationship with the participants' computer skills (P = 0.022). CONCLUSIONS: The mean of physicians' satisfaction with PACS was at a moderate to a high level, yet there are still problems in the successful implementation of these systems and establishing interoperability between them. PACS has not fully met all the demands of physicians and has not achieved its predetermined objectives, such as all-access from different locations.


Assuntos
Atitude do Pessoal de Saúde , Satisfação Pessoal , Médicos/psicologia , Intensificação de Imagem Radiográfica , Sistemas de Informação em Radiologia , Radiologia , Adulto , Atitude Frente aos Computadores , Feminino , Sistemas de Comunicação no Hospital , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Inquéritos e Questionários
11.
Braz Oral Res ; 34: e082, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785477

RESUMO

This study aims to assess the influence of high-density material on the radiographic diagnosis of proximal caries in digital systems with automatic exposure compensation, and to evaluate the effect of subjective adjustment of brightness and contrast to undertake this diagnostic task. Twenty bitewing radiographs of forty posterior human teeth with non-cavitated carious lesions, confirmed by micro-CT, were obtained with two digital systems. A porcelain-fused-to-metal crown attached to a titanium implant was inserted into the exposed area, and all the radiographs were repeated. Five radiologists assessed the radiographs and diagnosed proximal carious lesions. Afterwards, the observers were asked to adjust image brightness and contrast, based on their subjective perception, and to reassess the images. Thirty percent of each experimental group was reassessed to test intraobserver reproducibility, totaling 208 images per observer. Intraobserver and interobserver agreements ranged from fair to substantial. Sensitivity, specificity, predictive values, and area under the ROC curve were calculated and compared for each radiographic system, using ANOVA (α = 0.05). Overall, presence of high-density material and adjustment of brightness and contrast did not significantly influence the radiographic diagnosis of proximal caries (p ≥ 0.05). Regarding Digora Optime, adjustment of brightness and contrast significantly increased (p < 0.05) the diagnostic accuracy of proximal carious lesions in the presence of high-density material. In conclusion, the presence of high-density material in the X-rayed region does not influence radiographic diagnosis of proximal caries. However, when it is present in the X-rayed area, subjective adjustment of brightness and contrast is recommended for use with the Digora Optime digital system.


Assuntos
Cárie Dentária , Radiografia Dentária Digital , Humanos , Variações Dependentes do Observador , Curva ROC , Intensificação de Imagem Radiográfica , Reprodutibilidade dos Testes
12.
Biosens Bioelectron ; 165: 112361, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32729494

RESUMO

The recent outbreak of the coronavirus disease (COVID-19) has left the world clueless. As the WHO declares this new contagion as a pandemic on the 11th of March 2020, the alarming rate of the spawn of the disease in such a short period has disarranged the globe. Standing against this situation researchers are strenuously searching for the key traits responsible for this pandemic. As knowledge regarding the dynamics and host-path interaction of COVID-19 causing Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is currently unknown, the formulation of strategies concerning antiviral treatment, vaccination, and epidemiological control stands crucial. Before designing adequate therapeutic strategies, it is extremely essential to diagnose the disease at the outset as early detection can have a greater impact on building health system capacity. Hence, a comprehensive review of strategies for COVID-19 diagnosis is essential in this existing global situation. In this review, sequentially, we have provided the clinical details along with genetic and proteomic biomarkers related to COVID-19. The article systematically enlightens a clear overview of the clinically adopted techniques for the detection of COVID-19 including oligonucleotide-based molecular detection, Point-of-Care immunodiagnostics, radiographical analysis/sensing system, and newly developed biosensing prototypes having commercial viability. The commercial kits/analytical methods based-sensing strategies have also been tabulated categorically. The critical insights on the developer, commercial brand name, detection methods, technical operational details, detection time, clinical specimen, status, the limit of detection/detection ability have been discussed comprehensively. We believe that this review may provide scientists, clinicians and healthcare manufacturers valuable information regarding the most recent developments/approaches towards COVID-19 diagnosis.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas Biossensoriais/métodos , Infecções por Coronavirus/diagnóstico , Dispositivos Lab-On-A-Chip , Pneumonia Viral/diagnóstico , Testes Imediatos , Animais , Anticorpos Imobilizados/química , Betacoronavirus/genética , Biomarcadores/análise , Técnicas Biossensoriais/instrumentação , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Infecções por Coronavirus/sangue , Infecções por Coronavirus/virologia , Desenho de Equipamento , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Nanoestruturas/química , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/virologia , Intensificação de Imagem Radiográfica/instrumentação , Intensificação de Imagem Radiográfica/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/instrumentação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
13.
Br J Radiol ; 93(1114): 20200495, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32667855

RESUMO

As tomosynthesis is rapidly adopted by breast imaging practices, tomosynthesis-guided procedures are increasingly being performed. Tomosynthesis-guided needle localizations are feasible and efficient and allow for localization of tomosynthesis-only findings or one-view findings, which may be difficult to localize under standard digital mammography. In this review, we describe our step-by-step approach for performing tomosynthesis-guided localizations of the breast and axilla using a standard tomosynthesis unit.


Assuntos
Axila/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Biópsia Guiada por Imagem/métodos , Axila/patologia , Neoplasias da Mama/patologia , Feminino , Humanos , Mamografia , Intensificação de Imagem Radiográfica
14.
Medicine (Baltimore) ; 99(26): e20804, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32590765

RESUMO

The aim of this study was to evaluate the effect of a novel 4-dimensional similarity filter (4DSF) on quantitative and qualitative parameters of low-dose dynamic myocardial computed tomography perfusion (CTP) images.In this retrospective study, medical records of 32 patients with suspected or known coronary artery disease who underwent dynamic myocardial CTP at 80 kV were included. The 4DSF reduces noise by averaging voxels that have similar dynamic behavior after adaptive iterative dose reduction 3D (AIDR3D) and deformable image registration were applied. Qualitative (artefact, contour sharpness, and myocardial homogeneity [1 = poor; 2 = intermediate; 3 = good]) and quantitative measurement (standard deviation [SD] and signal-to-noise ratio [SNR]) were compared between the 4DSF and AIDR3D. Contrast-to-noise ratio (CNR) between ischemic and normal remote myocardium was also assessed using myocardial perfusion magnetic resonance imaging as the reference standard in seven patients.The 4DSF was successfully applied to all the images. Improvement in subjective image quality yielded by 4DSF was higher than that yielded by AIDR3D (homogeneity, 1.0 [3 vs 2]; artefact, 1.5 [3 vs 1.5]; P < .001) in all patients. The 4DSF significantly decreased the SD by 59% (AIDR3D vs 4DSF: 33.5 ±â€Š0.4 vs 13.8 ±â€Š0.4, P < .001), increased the SNR by 134% (AIDR3D vs 4DSF: 4.4 ±â€Š0.2 vs 10.3 ±â€Š0.2, P < .001), and increased the CNR by 131% (AIDR3D vs 4DSF: 1.6 ±â€Š0.2 vs 3.7 ±â€Š0.2, P < .001).The 4DSF improved the qualitative and quantitative parameters of low-dose dynamic myocardial CTP images.


Assuntos
Doença da Artéria Coronariana/diagnóstico , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada por Raios X , Feminino , Humanos , Japão , Masculino , Registros Médicos/estatística & dados numéricos , Pessoa de Meia-Idade , Melhoria de Qualidade , Intensificação de Imagem Radiográfica/métodos , Saúde Radiológica , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodos
16.
PLoS One ; 15(6): e0234644, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32544172

RESUMO

OBJECTIVES: To compare objective and subjective image quality of bronchial structures between a 512-pixel and a 1024-pixel image matrix for chest CT in phantoms and in patients. MATERIALS AND METHODS: First, a two-size chest phantom was imaged at two radiation doses on a 192-slice CT scanner. Datasets were reconstructed with 512-, 768-, and 1024-pixel image matrices and a sharp reconstruction kernel (Bl64). Image sharpness and normalized noise power spectrum (nNPS) were quantified. Second, chest CT images of 100 patients were reconstructed with 512- and 1024-pixel matrices and two blinded readers independently assessed objective and subjective image quality. In each patient dataset, the highest number of visible bronchi was counted for each lobe of the right lung. A linear mixed effects model was applied in the phantom study and a Welch's t-test in the patient study. RESULTS: Objective image sharpness and image noise increased with increasing matrix size and were highest for the 1024-matrix in phantoms and patients (all, P<0.001). nNPS was comparable among the three matrices. Objective image noise was on average 16% higher for the 1024-matrix compared to the 512-matrix in patients (P<0.0001). Subjective evaluation in patients yielded improved sharpness but increased image noise for the 1024- compared to the 512-matrix (both, P<0.001). There was no significant difference between highest-order visible bronchi (P>0.07) and the overall bronchial image quality between the two matrices (P>0.22). CONCLUSION: Our study demonstrated superior image sharpness and higher image noise for a 1024- compared to a 512-pixel matrix, while there was no significant difference in the depiction and subjective image quality of bronchial structures for chest CT.


Assuntos
Brônquios/diagnóstico por imagem , Radiografia Torácica/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Doses de Radiação , Intensificação de Imagem Radiográfica , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/normas , Radiografia Torácica/normas , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/normas
17.
Occup Environ Med ; 77(9): 597-602, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32471837

RESUMO

OBJECTIVES: To investigate the potential of deep learning in assessing pneumoconiosis depicted on digital chest radiographs and to compare its performance with certified radiologists. METHODS: We retrospectively collected a dataset consisting of 1881 chest X-ray images in the form of digital radiography. These images were acquired in a screening setting on subjects who had a history of working in an environment that exposed them to harmful dust. Among these subjects, 923 were diagnosed with pneumoconiosis, and 958 were normal. To identify the subjects with pneumoconiosis, we applied a classical deep convolutional neural network (CNN) called Inception-V3 to these image sets and validated the classification performance of the trained models using the area under the receiver operating characteristic curve (AUC). In addition, we asked two certified radiologists to independently interpret the images in the testing dataset and compared their performance with the computerised scheme. RESULTS: The Inception-V3 CNN architecture, which was trained on the combination of the three image sets, achieved an AUC of 0.878 (95% CI 0.811 to 0.946). The performance of the two radiologists in terms of AUC was 0.668 (95% CI 0.555 to 0.782) and 0.772 (95% CI 0.677 to 0.866), respectively. The agreement between the two readers was moderate (kappa: 0.423, p<0.001). CONCLUSION: Our experimental results demonstrated that the deep leaning solution could achieve a relatively better performance in classification as compared with other models and the certified radiologists, suggesting the feasibility of deep learning techniques in screening pneumoconiosis.


Assuntos
Aprendizado Profundo , Pneumoconiose/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Idoso , China , Poeira , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Redes Neurais de Computação , Exposição Ocupacional/efeitos adversos , Curva ROC , Radiografia Torácica/métodos , Radiologistas , Reprodutibilidade dos Testes , Estudos Retrospectivos
18.
Radiol Med ; 125(12): 1280-1287, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32385827

RESUMO

PURPOSE: We investigate the use of ratio of lesion to cortex (L/C) attenuation and aorta-lesion attenuation difference (ALAD) on multiphase contrast-enhanced CT to help distinguish oncocytoma from clear cell RCC in small renal masses (diameter < 4 cm). METHODS: We retrospectively identified 76 patients that undergo CT before surgery for a suspicious small renal mass between January 2014 and December 2018 with pathological diagnosis of 21 oncocytomas (ROs), 25 clear cell RCCs, 7 chromophobe RCCs, 7 papillary RCCs, 7 multilocular cystic RCCs, 7 angiomyolipomas and 2 leiomyomas. CT attenuation values were obtained for the tumor, the normal renal cortex and the aorta, placing a circular region of interest (ROI) in the same slice by two radiologists, independently. RESULTS: In the corticomedullary phase, ROs showed isodense enhancement to the renal cortex (ratio L/C 0.92 ± 0.12), while clear cell RCCs appeared hypodense to the renal cortex (ratio L/C 0.69 ± 0.20; p < 0.01) with an accuracy of 80% for diagnosing RO. In nephrographic phase, the ratio L/C attenuation was lower than the corticomedullary phase in ROs (0.78 ± 0.11) showing an early washout pattern, while the ratio L/C was similar to the corticomedullary phase in clear cell RCCs (0.69 ± 0.13; p = 0.025, with an accuracy of 65% for diagnosing RO). The ratio L/C attenuation showed considerable overlap between ROs and clear cell RCCs in the excretory phase (p = 0.27). Mean ALAD values in the nephrographic phase were 21.95 ± 16.24 for ROs and 36.96 ± 30.53 for clear cell RCCs (p = 0.049). CONCLUSION: The ratio L/C attenuation in corticomedullary phase may be useful to differentiate RO from clear cell RCC.


Assuntos
Adenoma Oxífilo/diagnóstico por imagem , Aorta/diagnóstico por imagem , Carcinoma de Células Renais/diagnóstico por imagem , Córtex Renal/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adenoma Oxífilo/patologia , Adulto , Idoso , Angiomiolipoma/diagnóstico por imagem , Carcinoma Papilar/diagnóstico por imagem , Carcinoma Papilar/patologia , Carcinoma de Células Renais/patologia , Meios de Contraste , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Renais/patologia , Leiomioma/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Intensificação de Imagem Radiográfica , Estudos Retrospectivos , Carga Tumoral
19.
Radiol Med ; 125(12): 1225-1232, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32415477

RESUMO

PURPOSE: To determine the intra- and extralesional factors that predict sclerotic degeneration of hepatic hemangiomas in the cirrhotic liver on long-term follow-up computed tomography (CT) examinations. MATERIALS AND METHODS: Fifty-seven hepatic hemangiomas (> 5 mm in diameter) in 41 cirrhotic patients, recruited over a 5-year period (January 2005-December 2009), were subjected to CT to determine which factors predict sclerotic contraction or degeneration in hemangiomas. Prior and follow-up CT examinations (from 2000 to 2018) were included to observe time-related changes. The patients' gender, age, cause of cirrhosis, progression of background liver cirrhosis, lesion size/location/contrast enhancement pattern, and serum aspartate transaminase to platelet ratio index were correlated with sclerotic changes of each lesion. RESULTS: According to the dynamic CT features, 36 of 57 (63%) hemangiomas were determined to have sclerotic changes during the follow-up period (1.1-14.4 years, median: 7.8 years), including 28 lesions (49%) reduced by ≥ 20% in diameter. In univariate analysis, age (p = 0.047) and morphological progression of background cirrhosis (p = 0.013) were significantly related to sclerotic change of hemangiomas. In the logistic regression analysis, only morphological progression of background liver cirrhosis independently predicted sclerotic change (odds ratio: 4.88, p = 0.007). With the exception of exophytic location free from size reduction (p = 0.023 in multivariate analysis), no other analyzed factors were significantly correlated with sclerotic changes. CONCLUSION: Overall, sclerotic changes of hepatic cavernous hemangioma followed the morphological progression of background liver cirrhosis, while exophytic lesions tended to be free of size reduction.


Assuntos
Meios de Contraste , Hemangioma Cavernoso/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Análise de Variância , Análise de Dados , Progressão da Doença , Feminino , Seguimentos , Hemangioma Cavernoso/patologia , Humanos , Fígado/patologia , Cirrose Hepática/patologia , Neoplasias Hepáticas/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Intensificação de Imagem Radiográfica , Esclerose , Fatores de Tempo , Carga Tumoral
20.
AJR Am J Roentgenol ; 215(2): 488-493, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32406770

RESUMO

OBJECTIVE. The aim of this study was to develop a low-dose radiography protocol for the neonatal ICU (NICU) using a new mobile digital radiography system with advanced denoising image processing and to evaluate the noninferiority of that protocol. SUBJECTS AND METHODS. In this prospective randomized study, 40 neonates in the NICU underwent radiography of the thorax and abdomen with two different mobile radiography units: conventional technique on one unit (50 kV, 1.6 mAs, and no additional filtration) and a new technique on another unit (54 kV, 0.1-mm Cu filtration). Three low-dose protocols for the second unit were developed in a phantom study: protocol A (100% equivalent dose with conventional protocol), protocol B (80% equivalent dose), and protocol C (64% equivalent dose). The noninferiority of each low-dose protocol was assessed by three independent readers using image quality criteria. RESULTS. Forty patients each underwent three pairs of radiography examinations (protocol A and the conventional protocol, protocol B and the conventional protocol, and protocol C and the conventional protocol), except one pair that did not include one image of the conventional protocol. The interrater reliability among the three readers was 0.91 (p < 0.001). Both of the low-dose protocols (B and C) were statistically noninferior to the conventional protocol with respect to overall image quality. Protocol B better depicted almost all anatomic landmarks and had better overall image quality than the conventional protocol. CONCLUSION. Using appropriate technique and acquisition factors, radiation dose can be lowered on a digital radiography system without significant effect on the image quality by adding filtrations and a new denoising technique.


Assuntos
Intensificação de Imagem Radiográfica/métodos , Intensificação de Imagem Radiográfica/normas , Protocolos Clínicos , Feminino , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Imagens de Fantasmas , Estudos Prospectivos , Doses de Radiação , Método Simples-Cego
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