Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Phys Med ; 114: 102681, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37748358

RESUMO

PURPOSE: Steadily increasing use of computational/virtual phantoms in medical physics has motivated expanding development of new simulation methods and data representations for modelling human anatomy. This has emphasized the need for increased realism, user control, and availability. In breast cancer research, virtual phantoms have gained an important role in evaluating and optimizing imaging systems. For this paper, we have developed an algorithm to model breast abnormalities based on fractal Perlin noise. We demonstrate and characterize the extension of this approach to simulate breast lesions of various sizes, shapes, and complexity. MATERIALS AND METHOD: Recently, we developed an algorithm for simulating the 3D arrangement of breast anatomy based on Perlin noise. In this paper, we have expanded the method to also model soft tissue breast lesions. We simulated lesions within the size range of clinically representative breast lesions (masses, 5-20 mm in size). Simulated lesions were blended into simulated breast tissue backgrounds and visualized as virtual digital mammography images. The lesions were evaluated by observers following the BI-RADS assessment criteria. RESULTS: Observers categorized the lesions as round, oval or irregular, with circumscribed, microlobulated, indistinct or obscured margins. The majority of the simulated lesions were considered by the observers to have a realism score of moderate to well. The simulation method provides almost real-time lesion generation (average time and standard deviation: 1.4 ± 1.0 s). CONCLUSION: We presented a novel algorithm for computer simulation of breast lesions using Perlin noise. The algorithm enables efficient simulation of lesions, with different sizes and appearances.


Assuntos
Neoplasias da Mama , Fractais , Humanos , Feminino , Simulação por Computador , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Mamografia/métodos , Mama/diagnóstico por imagem , Mama/patologia , Imagens de Fantasmas
2.
Artif Intell Med ; 142: 102555, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37316093

RESUMO

Digital mammography is currently the most common imaging tool for breast cancer screening. Although the benefits of using digital mammography for cancer screening outweigh the risks associated with the x-ray exposure, the radiation dose must be kept as low as possible while maintaining the diagnostic utility of the generated images, thus minimizing patient risks. Many studies investigated the feasibility of dose reduction by restoring low-dose images using deep neural networks. In these cases, choosing the appropriate training database and loss function is crucial and impacts the quality of the results. In this work, we used a standard residual network (ResNet) to restore low-dose digital mammography images and evaluated the performance of several loss functions. For training purposes, we extracted 256,000 image patches from a dataset of 400 images of retrospective clinical mammography exams, where dose reduction factors of 75% and 50% were simulated to generate low and standard-dose pairs. We validated the network in a real scenario by using a physical anthropomorphic breast phantom to acquire real low-dose and standard full-dose images in a commercially available mammography system, which were then processed through our trained model. We benchmarked our results against an analytical restoration model for low-dose digital mammography. Objective assessment was performed through the signal-to-noise ratio (SNR) and the mean normalized squared error (MNSE), decomposed into residual noise and bias. Statistical tests revealed that the use of the perceptual loss (PL4) resulted in statistically significant differences when compared to all other loss functions. Additionally, images restored using the PL4 achieved the closest residual noise to the standard dose. On the other hand, perceptual loss PL3, structural similarity index (SSIM) and one of the adversarial losses achieved the lowest bias for both dose reduction factors. The source code of our deep neural network is available at https://github.com/WANG-AXIS/LdDMDenoising.


Assuntos
Mama , Mamografia , Humanos , Estudos Retrospectivos , Bases de Dados Factuais , Redes Neurais de Computação
3.
Oncol Rep ; 45(6)2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33907843

RESUMO

The current study aimed to evaluate the accuracy of diffusion­weighted imaging and morphological aspects at 3 Tesla (T) and 1.5T MRI for diagnosing metastatic lymph nodes (LN) in cervical cancer. A retrospective study was conducted at the Barretos Cancer Hospital. A total of 45 patients with cervical cancer who underwent MRI examination and pelvic and/or para­aortic lymphadenectomy as part of surgical procedure were included. Data regarding LN images included size (short­axis diameters), morphology (usual, rounded or amorphous), appearance (homogeneous or heterogeneous), limits (regular, irregular or imprecise), presence or absence of necrosis, diffusion (normal or greater restriction than expected for normal tissue) and aspect (suspected, undetermined or normal). These findings were compared with histopathological results. According to histology results, among the 45 patients, 14 (31.1%) LNs were tested positive for metastasis and 31 (68.9%) LNs were tested negative. A total of 41 metastatic positive LNs were detected from a total of 976 resected nodes. Twelve patients from the 45 (26.7%) had LN classified as metastatic by histology and suspected by MRI, 26 (57.8%) as negative in both evaluations, 2 (4.4%) as positive by histology and negative by MRI and five (11.1%) as negative by histology and positive by MRI. Based on these results, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 85.7, 83.9, 70.6, 92.9 and 84.4%, respectively. The Cohen's κ test exposed a general outcome of 0.657 (P<0.05), demonstrating that the two variables (histology and MRI) have substantial concordance. The κ test results between histological and MRI data for paraaortic and pelvic LNs were found to be 1 and 0.657, respectively. Finally, short axis >10 mm, T2 hypointensity, rounded morphology and greater restriction than expected for normal tissues are the four most common MRI findings associated with metastatic LN. The concordance between MRI and histology was substantial, indicating that this method using MRI for diagnosing suspected LN metastasis is reliable. The results of the current study revealed that the most important aspects to be evaluated in MRI include: Short axis >10 mm, T2 hypointensity, rounded morphology and greater restriction than expected for normal tissues. If these four characteristics are present in MRI, histological evaluation is likely to reveal positive lymph node metastasis.


Assuntos
Linfonodos/diagnóstico por imagem , Metástase Linfática/diagnóstico , Imageamento por Ressonância Magnética , Neoplasias do Colo do Útero/patologia , Adulto , Idoso , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática/patologia , Pessoa de Meia-Idade , Pelve , Valor Preditivo dos Testes , Estudos Retrospectivos , Neoplasias do Colo do Útero/diagnóstico
4.
Phys Med Biol ; 65(22): 225035, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33231201

RESUMO

In this work we model the noise properties of a computed radiography (CR) mammography system by adding an extra degree of freedom to a well-established noise model, and derive a variance-stabilizing transform (VST) to convert the signal-dependent noise into approximately signal-independent. The proposed model relies on a quadratic variance function, which considers fixed-pattern (structural), quantum and electronic noise. It also accounts for the spatial-dependency of the noise by assuming a space-variant quantum coefficient. The proposed noise model was compared against two alternative models commonly found in the literature. The first alternative model ignores the spatial-variability of the quantum noise, and the second model assumes negligible structural noise. We also derive a VST to convert noisy observations contaminated by the proposed noise model into observations with approximately Gaussian noise and constant variance equals to one. Finally, we estimated a look-up table that can be used as an inverse transform in denoising applications. A phantom study was conducted to validate the noise model, VST and inverse VST. The results show that the space-variant signal-dependent quadratic noise model is appropriate to describe noise in this CR mammography system (errors< 2.0% in terms of signal-to-noise ratio). The two alternative noise models were outperformed by the proposed model (errors as high as 14.7% and 9.4%). The designed VST was able to stabilize the noise so that it has variance approximately equal to one (errors< 4.1%), while the two alternative models achieved errors as high as 26.9% and 18.0%, respectively. Finally, the proposed inverse transform was capable of returning the signal to the original signal range with virtually no bias.


Assuntos
Mamografia , Modelos Teóricos , Razão Sinal-Ruído , Algoritmos , Humanos , Distribuição Normal , Imagens de Fantasmas
5.
J Surg Oncol ; 122(7): 1498-1505, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32779228

RESUMO

OBJECTIVE: To evaluate the difference between early and delayed removal of indwelling urinary catheter after radical hysterectomy (RH) or radical trachelectomy (RT). METHODS: An ambispective study was conducted in early-stage cervical cancer patients who underwent RH or RT. Delayed indwelling urinary catheter removal occurred on a postoperative day (POD) 7 in the retrospective group (January 2012-November 2013), and early removal occurred on POD 1 in the prospective group (May 2014-June 2017). The postvoid residual (PVR) test was performed after indwelling catheter removal in both groups. RESULTS: Our sample included 47 patients in the delayed group and 48 in the early one. There was no difference in age, body mass index, tumor size, histology, stage, surgical approach, and intraoperative and postoperative complications. Indwelling urinary catheter reinsertion was needed in 16 (34%) patients in the delayed group and 12 (25%) in the early group (P = .37), with no statistical difference between the median PVR volumes -82.5 and 45 mL (P = .06), respectively. Seven (14.9%) patients in the delayed group presented with 30-day urinary tract infection vs two (4.2%) in the early group (P = .09). CONCLUSIONS: Early indwelling urinary catheter removal, in regard to the rate of catheter reinsertion and PVR volume, does not differ from delayed removal.


Assuntos
Cateteres de Demora , Remoção de Dispositivo , Cateteres Urinários , Neoplasias do Colo do Útero/cirurgia , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Histerectomia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia
6.
Lancet Oncol ; 21(6): 851-860, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32502445

RESUMO

BACKGROUND: In the phase 3 LACC trial and a subsequent population-level review, minimally invasive radical hysterectomy was shown to be associated with worse disease-free survival and higher recurrence rates than was open radical hysterectomy in patients with early stage cervical cancer. Here, we report the results of a secondary endpoint, quality of life, of the LACC trial. METHODS: The LACC trial was a randomised, open-label, phase 3, non-inferiority trial done in 33 centres worldwide. Eligible participants were women aged 18 years or older with International Federation of Gynaecology and Obstetrics (FIGO) stage IA1 with lymphovascular space invasion, IA2, or IB1 adenocarcinoma, squamous cell carcinoma, or adenosquamous carcinoma of the cervix, with an Eastern Cooperative Oncology Group performance status of 0 or 1, who were scheduled to have a type 2 or 3 radical hysterectomy. Participants were randomly assigned (1:1) to receive open or minimally invasive radical hysterectomy. Randomisation was done centrally using a computerised minimisation program, stratified by centre, disease stage according to FIGO guidelines, and age. Neither participants nor investigators were masked to treatment allocation. The primary endpoint of the LACC trial was disease-free survival at 4·5 years, and quality of life was a secondary endpoint. Eligible patients completed validated quality-of-life and symptom assessments (12-item Short Form Health Survey [SF-12], Functional Assessment of Cancer Therapy-Cervical [FACT-Cx], EuroQoL-5D [EQ-5D], and MD Anderson Symptom Inventory [MDASI]) before surgery and at 1 and 6 weeks and 3 and 6 months after surgery (FACT-Cx was also completed at additional timepoints up to 54 months after surgery). Differences in quality of life over time between treatment groups were assessed in the modified intention-to-treat population, which included all patients who had surgery and completed at least one baseline (pretreatment) and one follow-up (at any timepoint after surgery) questionnaire, using generalised estimating equations. The LACC trial is registered with ClinicalTrials.gov, NCT00614211. FINDINGS: Between Jan 31, 2008, and June 22, 2017, 631 patients were enrolled; 312 assigned to the open surgery group and 319 assigned to the minimally invasive surgery group. 496 (79%) of 631 patients had surgery completed at least one baseline and one follow-up quality-of-life survey and were included in the modified intention-to-treat analysis (244 [78%] of 312 patients in the open surgery group and 252 [79%] of 319 participants in the minimally invasive surgery group). Median follow-up was 3·0 years (IQR 1·7-4·5). At baseline, no differences in the mean FACT-Cx total score were identified between the open surgery (129·3 [SD 18·8]) and minimally invasive surgery groups (129·8 [19·8]). No differences in mean FACT-Cx total scores were identified between the groups 6 weeks after surgery (128·7 [SD 19·9] in the open surgery group vs 130·0 [19·8] in the minimally invasive surgery group) or 3 months after surgery (132·0 [21·7] vs 133·0 [22·1]). INTERPRETATION: Since recurrence rates are higher and disease-free survival is lower for minimally invasive radical hysterectomy than for open surgery, and postoperative quality of life is similar between the treatment groups, gynaecological oncologists should recommend open radical hysterectomy for patients with early stage cervical cancer. FUNDING: MD Anderson Cancer Center and Medtronic.


Assuntos
Adenocarcinoma/cirurgia , Carcinoma Adenoescamoso/cirurgia , Carcinoma de Células Escamosas/cirurgia , Histerectomia/métodos , Qualidade de Vida , Neoplasias do Colo do Útero/cirurgia , Adenocarcinoma/patologia , Adenocarcinoma/psicologia , Adulto , Idoso , Carcinoma Adenoescamoso/patologia , Carcinoma Adenoescamoso/psicologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/psicologia , Efeitos Psicossociais da Doença , Intervalo Livre de Doença , Feminino , Nível de Saúde , Humanos , Histerectomia/efeitos adversos , Saúde Mental , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Inquéritos e Questionários , Fatores de Tempo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/psicologia , Adulto Jovem
7.
Med Phys ; 46(6): 2683-2689, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30972769

RESUMO

PURPOSE: To investigate the use of an affine-variance noise model, with correlated quantum noise and spatially dependent quantum gain, for the simulation of noise in virtual clinical trials (VCT) of digital breast tomosynthesis (DBT). METHODS: Two distinct technologies were considered: an amorphous-selenium (a-Se) detector with direct conversion and a thallium-doped cesium iodide (CsI(Tl)) detector with indirect conversion. A VCT framework was used to generate noise-free projections of a uniform three-dimensional simulated phantom, whose geometry and absorption match those of a polymethyl methacrylate (PMMA) uniform physical phantom. The noise model was then used to generate noisy observations from the simulated noise-free data, while two clinically available DBT units were used to acquire projections of the PMMA physical phantom. Real and simulated projections were then compared using the signal-to-noise ratio (SNR) and normalized noise power spectrum (NNPS). RESULTS: Simulated images reported errors smaller than 4.4% and 7.0% in terms of SNR and NNPS, respectively. These errors are within the expected variation between two clinical units of the same model. The errors increase to 65.8% if uncorrelated models are adopted for the simulation of systems featuring indirect detection. The assumption of spatially independent quantum gain generates errors of 11.2%. CONCLUSIONS: The investigated noise model can be used to accurately reproduce the noise found in clinical DBT. The assumption of uncorrelated noise may be adopted if the system features a direct detector with minimal pixel crosstalk.


Assuntos
Mamografia , Modelos Estatísticos , Razão Sinal-Ruído , Ensaios Clínicos como Assunto , Humanos , Interface Usuário-Computador
8.
BMC Clin Pathol ; 18: 11, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30323716

RESUMO

BACKGROUND: to evaluate the intraobserver and interobserver reproducibility of cervical cytopathology according to previous knowledge of whether patients received radiotherapy (RT) treatment or not. METHODS: The study analyzed a sample of 95 cervix cytological slides; 24 with cytological abnormalities (CA) and presence of RT; 21 without CA and presence of RT; 25 without CA and without previous RT; 25 with CA and without previous RT. Two cytopathology (CP) evaluations of the slides were carried out. For the first CP re-evaluation, the cytotechnologist was blinded for the information of previous RT. For the second CP re-evaluation, the cytotechnologist was informed about previous RT. The results were analyzed through inter and intraobserver agreement using the unweighted and weighted kappa. RESULTS: Post radiotherapy effects were identified in 44.4% of cases that undergone previous pelvic RT. The agreement for RT status was 66.32% (unweighted K = 0.31, 95%CI: 0.13; 0.49, moderate agreement). The intraobserver agreement, regarding the cytological diagnoses, regardless of radiotherapy status, was 80.32% (weighted K = 0.52, 95%CI: 0.34; 0.68). In no RT group, the intraobserver agreement was 70% (weighted K = 0.47, 95%CI: 0.27;0.65) and in patients that received RT, the intraobserver agreement was 84.09% (unweighted K = 0.37, 95%CI: 0.01;0.74). The interobserver agreement between cytopathology result (abnormal or normal) in the group with RT, considering normal and abnormal CP diagnosis was 14.0% and 12.5%, respectively. There was no association between the cytological alterations and the median time between the end of RT and the cytological diagnosis. CONCLUSION: This study showed that RT has an important impact in CP diagnosis because the agreement, also in interobserver and intraobserver analysis, had high discrepancy in patients that received RT. Also, demonstrated that it is difficult to recognize the presence of RT in cytological slides when this information is not provided.

9.
IEEE Trans Med Imaging ; 36(11): 2331-2342, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28641248

RESUMO

This paper proposes a new method of simulating dose reduction in digital breast tomosynthesis, starting from a clinical image acquired with a standard radiation dose. It considers both signal-dependent quantum and signal-independent electronic noise. Furthermore, the method accounts for pixel crosstalk, which causes the noise to be frequency-dependent, thus increasing the simulation accuracy. For an objective assessment, simulated and real images were compared in terms of noise standard deviation, signal-to-noise ratio (SNR) and normalized noise power spectrum (NNPS). A two-alternative forced-choice (2-AFC) study investigated the similarity between the noise strength of low-dose simulated and real images. Six experienced medical physics specialists participated on the study, with a total of 2 160 readings. Objective assessment showed no relevant trends with the simulated noise. The relative error in the standard deviation of the simulated noise was less than 2% for every projection angle. The relative error of the SNR was less than 1.5%, and the NNPS of the simulated images had errors less than 2.5%. The 2-AFC human observer experiment yielded no statistically significant difference ( =0.84) in the perceived noise strength between simulated and real images. Furthermore, the observer study also allowed the estimation of a dose difference at which the observer perceived a just-noticeable difference (JND) in noise levels. The estimated JND value indicated that a change of 17% in the current-time product was sufficient to cause a noticeable difference in noise levels. The observed high accuracy, along with the flexible calibration, make this method an attractive tool for clinical image-based simulations of dose reduction.


Assuntos
Simulação por Computador , Mamografia/métodos , Doses de Radiação , Intensificação de Imagem Radiográfica/métodos , Algoritmos , Mama/diagnóstico por imagem , Feminino , Humanos , Imagens de Fantasmas , Razão Sinal-Ruído
10.
Med Phys ; 43(6): 2704-2714, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27277017

RESUMO

PURPOSE: This work proposes an accurate method for simulating dose reduction in digital mammography starting from a clinical image acquired with a standard dose. METHODS: The method developed in this work consists of scaling a mammogram acquired at the standard radiation dose and adding signal-dependent noise. The algorithm accounts for specific issues relevant in digital mammography images, such as anisotropic noise, spatial variations in pixel gain, and the effect of dose reduction on the detective quantum efficiency. The scaling process takes into account the linearity of the system and the offset of the detector elements. The inserted noise is obtained by acquiring images of a flat-field phantom at the standard radiation dose and at the simulated dose. Using the Anscombe transformation, a relationship is created between the calculated noise mask and the scaled image, resulting in a clinical mammogram with the same noise and gray level characteristics as an image acquired at the lower-radiation dose. RESULTS: The performance of the proposed algorithm was validated using real images acquired with an anthropomorphic breast phantom at four different doses, with five exposures for each dose and 256 nonoverlapping ROIs extracted from each image and with uniform images. The authors simulated lower-dose images and compared these with the real images. The authors evaluated the similarity between the normalized noise power spectrum (NNPS) and power spectrum (PS) of simulated images and real images acquired with the same dose. The maximum relative error was less than 2.5% for every ROI. The added noise was also evaluated by measuring the local variance in the real and simulated images. The relative average error for the local variance was smaller than 1%. CONCLUSIONS: A new method is proposed for simulating dose reduction in clinical mammograms. In this method, the dependency between image noise and image signal is addressed using a novel application of the Anscombe transformation. NNPS, PS, and local noise metrics confirm that this method is capable of precisely simulating various dose reductions.


Assuntos
Algoritmos , Simulação por Computador , Mamografia/métodos , Doses de Radiação , Artefatos , Mama/efeitos da radiação , Humanos , Modelos Lineares , Mamografia/instrumentação , Modelos Anatômicos , Imagens de Fantasmas
11.
Gynecol Oncol ; 138(3): 585-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26095894

RESUMO

OBJECTIVES: Radical trachelectomy is considered standard of care in patients with early-stage cervical cancer interested in future fertility. The goal of this study was to compare operative, oncologic, and fertility outcomes in patients with early-stage cervical cancer undergoing open vs. minimally invasive radical trachelectomy. METHODS: A retrospective review was performed of patients from four institutions who underwent radical trachelectomy for early-stage cervical cancer from June 2002 to July 2013. Perioperative, oncologic, and fertility outcomes were compared between patients undergoing open vs. minimally invasive surgery. RESULTS: A total of 100 patients were included in the analysis. Fifty-eight patients underwent open radical trachelectomy and 42 patients underwent minimally invasive surgery (MIS=laparoscopic or robotic). There were no differences in patient age, body mass index, race, histology, lymph vascular space invasion, or stage between the two groups. The median surgical time for MIS was 272min [range, 130-441min] compared with 270min [range, 150-373min] for open surgery (p=0.78). Blood loss was significantly lower for MIS vs. laparotomy (50mL [range, 10-225mL] vs. 300mL [50-1100mL]) (p<0.0001). Nine patients required blood transfusion, all in the open surgery group (p=0.010). Length of hospitalization was shorter for MIS than for laparotomy (1day [1-3 days] vs. 4days [1-9 days]) (p<0.0001). Three intraoperative complications occurred (3%): 1 bladder injury, and 1 fallopian tube injury requiring unilateral salpingectomy in the MIS group and 1 vascular injury in the open surgery group. The median lymph node count was 17 (range, 5-47) for MIS vs. 22 (range, 7-48) for open surgery (p=0.03). There were no differences in the rate of postoperative complications (30% MIS vs. 31% open surgery). Among 83 patients who preserved their fertility (33 MIS vs. 50 open surgery), 34 (41%) patients attempted to get pregnant. Sixteen (47%) patients were able to do so (MIS: 2 vs. laparotomy: 14, p=0.01). The pregnancy rate was higher in the open surgery group when compared to the MIS group (51% vs. 28%, p=0.018). However, median follow-up was shorter is the MIS group compared with the open surgery group (25months [range, 10-69] vs. 66months [range, 11-147]). To date, there has been one recurrence in the laparotomy group and none in the MIS group. CONCLUSIONS: Our results suggest that radical trachelectomy via MIS results in less blood loss and a shorter hospital stay. Fertility rates appear higher in patients undergoing open radical trachelectomy.


Assuntos
Procedimentos Cirúrgicos em Ginecologia/métodos , Neoplasias do Colo do Útero/cirurgia , Adulto , Feminino , Preservação da Fertilidade , Humanos , Laparotomia/efeitos adversos , Laparotomia/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Recidiva Local de Neoplasia/cirurgia , Gravidez , Estudos Retrospectivos , Neoplasias do Colo do Útero/patologia
13.
Acta Obstet Gynecol Scand ; 93(9): 941-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24974761

RESUMO

OBJECTIVE: To develop a prognostic model for women who underwent surgical treatment for cervical intraepithelial neoplasia. DESIGN: Cohort study. Patient inclusion and follow-up occurred retrospectively and prospectively. SETTING: Barretos Cancer Hospital, Barretos, São Paulo, Brazil. POPULATION: Women (n = 242) diagnosed with cervical intraepithelial neoplasia who were submitted to conization. METHODS: Immediately prior to surgical treatment, a cervical cytology sample was collected from each individual included in the study by endocervical brushing and stored in a preservative solution with methanol. A human papilloma virus-DNA test was conducted using an aliquot of the endocervical brushings. The surgical specimens were subjected to immunohistochemical analysis of p16 (immunohistochemical analysis 4a) protein expression. MAIN OUTCOME MEASURES: Two-year disease-free survival rates calculated for each study variable. Identified variables in the multivariate Cox model were used for elaboration of prognostic scores. RESULTS: Variables associated with outcome included age (p = 0.033), tobacco use (p < 0.001), final histopathological diagnosis (p = 0.007), surgical margins (p < 0.001), high-risk human papilloma virus status (p = 0.008), human papilloma virus-16 status (p < 0.001) and immunoexpression of p16 in the cytoplasm (p = 0.049). By the Cox model, independent risk factors for disease recurrence/persistence were: tobacco use (hazard risk = 3.0; 95% confidence interval 1.6-5.6), positive surgical margins (hazard risk = 3.2; 95% confidence interval 1.6-6.1), human papilloma virus-16 (hazard risk = 3.3; 95% confidence interval 1.6-6.9) and age over 45 years (hazard risk = 2.7; 95% confidence interval 1.1-6.6). CONCLUSIONS: Establishment of a prognostic score can represent a valuable tool for determining the risk of cervical intraepithelial neoplasia recurrence after conization. The use of clinical (age and tobacco use), pathological (surgical margins) and molecular (human papilloma virus-16 genotyping) factors can facilitate more appropriate patient follow up according to risk stratification.


Assuntos
Modelos Anatômicos , Displasia do Colo do Útero/cirurgia , Neoplasias do Colo do Útero/cirurgia , Idoso , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Período Pós-Operatório , Prognóstico , Fatores de Risco , Resultado do Tratamento , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/patologia
14.
J Digit Imaging ; 26(2): 183-97, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22806627

RESUMO

A new restoration methodology is proposed to enhance mammographic images through the improvement of contrast features and the simultaneous suppression of noise. Denoising is performed in the first step using the Anscombe transformation to convert the signal-dependent quantum noise into an approximately signal-independent Gaussian additive noise. In the Anscombe domain, noise is filtered through an adaptive Wiener filter, whose parameters are obtained by considering local image statistics. In the second step, a filter based on the modulation transfer function of the imaging system in the whole radiation field is applied for image enhancement. This methodology can be used as a preprocessing module for computer-aided detection (CAD) systems to improve the performance of breast cancer screening. A preliminary assessment of the restoration algorithm was performed using synthetic images with different levels of quantum noise. Afterward, we evaluated the effect of the preprocessing on the performance of a previously developed CAD system for clustered microcalcification detection in mammographic images. The results from the synthetic images showed an increase of up to 11.5 dB (p = 0.002) in the peak signal-to-noise ratio. Moreover, the mean structural similarity index increased up to 8.3 % (p < 0.001). Regarding CAD performance, the results suggested that the preprocessing increased the detectability of microcalcifications in mammographic images without increasing the false-positive rates. Receiver operating characteristic analysis revealed an average increase of 14.1 % (p = 0.01) in overall CAD performance when restored image sets were used.


Assuntos
Artefatos , Doenças Mamárias/diagnóstico por imagem , Mamografia/métodos , Interpretação de Imagem Radiográfica Assistida por Computador , Feminino , Humanos , Mamografia/instrumentação , Imagens de Fantasmas , Curva ROC , Intensificação de Imagem Radiográfica/métodos , Sensibilidade e Especificidade , Razão Sinal-Ruído
15.
GED gastroenterol. endosc. dig ; 29(4): 143-145, out.-dez. 2010. ilus
Artigo em Português | LILACS | ID: lil-602455

RESUMO

A Síndrome de Budd-chiari é caracterizada pela oclusão das veias supra-hepáticas e apresenta inúmeras causas, mas nenhuma delas é identificável em cerca de 60-70% dos pacientes. O diagnóstico é realizado pela suspeita clínica e confirmado por exames complementares, sendo a ultrassonografia com Doppler a mais sensível (85%). A terapia varia desde medicamentos, cirurgias como anastomoses portossistêmicos e transplante hepático até métodos menos invasivos como derivação intra-hepática portossistêmica transjugular (TIPS) e angioplastia. O objetivo desse trabalho é apresentar um paciente portador da SBC submetido à angioplastia transjugular da veia supra-hepática, utilizando via anterógrada (punção através da veia cava inferior trans-hepática, atingindo a veia supra-hepática e recanalizando anterogradamente a veia supra-hepática).


The Budd-chiari syndrome is characterized by occlusion of the supra-hepatic veins and has any causes, but none of them are identifiable by about 60-70% of patients. The diagnosis is made by clinical suspicion and confirmed by additional tests, and the Doppler ultrasound with the most sensitive (85%). The therapy varies from medications, surgeries such as liver transplantation and anastomosis portossistêmicos even less invasive methods like bypass intra-hepatic portosystemic transjugular (TIPS) and angioplasty. The aim of this article is to present a patient of SBC submitted to angioplasty transjugular the above hepatic vein using antegrade route (puncture through the inferior vena cava reaching the above-hepatic vein and the vein recanalizando anterograde above-liver).


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Angioplastia , Derivação Portossistêmica Transjugular Intra-Hepática , Síndrome de Budd-Chiari , Síndrome de Budd-Chiari/diagnóstico por imagem
16.
GED gastroenterol. endosc. dig ; 29(3): 90-92, jul.-set. 2010. ilus
Artigo em Português | LILACS | ID: lil-590956

RESUMO

Pileflebite é uma complicação incomum das infecções intra-abdominais e está associada à alta mortalidade. A patogenia ainda não está esclarecida. O diagnóstico permanece difícil e frequentemente é tardio, uma vez que a clínica é inespecífica e é necessário um elevado grau de suspeição. Na maioria dos casos, o prognóstico é favorável. O fator mais importante é a precocidade no diagnóstico e a imediata antibioticoterapia específica. Relatamos um caso de um paciente com diagnóstico de pileflebite mesentérica secundária à diverticulite colônica.


Pylephlebitis is a uncommon complications of intraabdominalsuppuration and associated with high mortality. The pathogenic is not clear and diagnosis remains delay because of its nonspecific symptoms and is necessary high clinical suspicion. In the major of cases the prognostic is favorable. The most important determinants for the prognosis is earlydiagnosis and adequate medical. We report a case of patient with diagnosis of mesenteric Pylephlebitis secondary a colonic diverticulitis.


Assuntos
Humanos , Masculino , Idoso de 80 Anos ou mais , Veia Porta , Tromboflebite , Doença Diverticular do Colo , Infecções Intra-Abdominais
17.
Artigo em Português | LILACS | ID: lil-538851

RESUMO

JUSTIFICATIVA E OBJETIVOS: A paracoccidioidomicose é uma doença granulomatosa crônica causada por um fungo e acomete principalmente os pulmões e a pele. A clínica é variada e o envolvimento do sistema nervoso central (SNC) é raro. Quando não diagnosticada e tratada oportunamente pode levar às formas disseminadas graves e letais. O objetivo desse estudo foi demonstrar as características clínicas da rara apresentação dessa doença. RELATO DO CASO: Paciente do sexo masculino, 26 anos, imunocompetente, apresentava paracoccidiodomicose recidivante com envolvimento do SNC. CONCLUSÃO: Apesar de ser uma doença rara, deve-se ter em mente que a neuroparacoccidiodomicose pode atingir pacientes imunocompetentes. Portanto deve-se fazer o diagnóstico e o tratamento de forma precoce.


Assuntos
Humanos , Masculino , Adulto , Paracoccidioidomicose/complicações , Sistema Nervoso Central , Micoses , Medicina Interna
18.
Rev. Soc. Bras. Clín. Méd ; 7(3): 202-203, maio-jun. 2009. ilus
Artigo em Português | LILACS | ID: lil-518181

RESUMO

JUSTIFICATIVA E OBJETIVOS: A doença de Weber Christianou paniculite lobular idiopática é uma doença rara, que se apresenta com inflamação recorrente da camada adiposa da pele. O objetivo deste estudo foi descrever o quadro clínico dessa doença e informar sobre sua presença e impacto na qualidade de vida dos pacientes. RELATO DO CASO: Paciente do sexo feminino, portadora dessa doença, que ficou 20 anos sem diagnóstico, mas quando se detectou sua presença foi possível a remissão. CONCLUSÃO: A importância do caso descrito está em demonstrar como a falta de diagnóstico interfere na qualidade devida dos pacientes, portanto é bom lembrar que doenças raras acontecem e seu diagnóstico só é feito quando se pensam em hipóteses e diagnósticos diferenciais, quesitos esses indispensáveis para o exercício da clínica médica.


BACKGROUND AND OBJECTIVES: Weber Christian disease or idiopathic lobular pannicullitis is a skin condition that features recurring inflammation in the fat layer of the skin. The aim of this article is to describe this rare pathology, the clinical findings and remember your presence and their impact on patient's quality of life. CASE REPORT: Female patient, we report a case of patient with Weber Christian disease that was undiagnosed for 20 years and, when it was done it was possible to remission of the disease. CONCLUSION: The importance of the case described is to demonstrate how the lack of diagnosis interfere with the quality of life of patients and we always remember that rare diseases occurand their diagnosis is only made when thinking about chance and differential diagnosis, these questions essential to the exercise of clinical practice.


Assuntos
Humanos , Feminino , Adulto , Medicina Interna , Paniculite Nodular não Supurativa/diagnóstico
19.
GED gastroenterol. endosc. dig ; 27(6): 187-190, nov.-dez. 2008. ilus
Artigo em Português | LILACS | ID: lil-592390

RESUMO

Tumores carcinóides têm origem nas células neuroendócrinas e foram descritos há cerca de cem anos por Lubarsch. Sua incidência gira em torno de 0,7 caso/100.000 habitantes. A localização pancreática é rara com incidência de 0,75% dos tumores carcinóides do trato digestivo. O objetivo desse trabalho é relatar caso de paciente portador de tumor carcinóide pancreático tratado através de ressecção tumoral por via laparoscópica.


Assuntos
Humanos , Masculino , Adulto , Tumor Carcinoide , Neoplasias Pancreáticas/cirurgia , Laparoscopia , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA