Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
Diagn Interv Imaging ; 101(1): 35-44, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31358460

RESUMO

PURPOSE: The purpose of this study was to report procedures developed to annotate abdominal computed tomography (CT) images from subjects without pancreatic disease that will be used as the input for deep convolutional neural networks (DNN) for development of deep learning algorithms for automatic recognition of a normal pancreas. MATERIALS AND METHODS: Dual-phase contrast-enhanced volumetric CT acquired from 2005 to 2009 from potential kidney donors were retrospectively assessed. Four trained human annotators manually and sequentially annotated 22 structures in each datasets, then expert radiologists confirmed the annotation. For efficient annotation and data management, a commercial software package that supports three-dimensional segmentation was used. RESULTS: A total of 1150 dual-phase CT datasets from 575 subjects were annotated. There were 229 men and 346 women (mean age: 45±12years; range: 18-79years). The mean intra-observer intra-subject dual-phase CT volume difference of all annotated structures was 4.27mL (7.65%). The deep network prediction for multi-organ segmentation showed high fidelity with 89.4% and 1.29mm in terms of mean Dice similarity coefficients and mean surface distances, respectively. CONCLUSIONS: A reliable data collection/annotation process for abdominal structures was developed. This process can be used to generate large datasets appropriate for deep learning.


Assuntos
Abdome/diagnóstico por imagem , Aprendizado Profundo , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
3.
Inflamm Bowel Dis ; 10(4): 357-60, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15475743

RESUMO

BACKGROUND: Jejunoileitis (JI) is an unusual manifestation of Crohn's disease (CD) that has been associated with high morbidity and the frequent need for surgical intervention. Although the disease has been well-described in adults, the true prevalence and clinical phenotype in children is unknown. AIM: To compare the clinical course and nutritional impact of CD in children with and without proximal small bowel involvement. METHODS: Patients with either Crohn's jejunitis or JI with or without colonic involvement were identified through a clinical database (1996--2002). All radiologic studies were reviewed by an experienced radiologist blinded to the clinical diagnosis. Thirty-six patients with CD without histologic or radiologic signs of proximal small bowel involvement were used for comparison. All medical, surgical, and hematologic parameters were compared in both disease groups. RESULTS: Among the 134 patients with CD, 23 (17%) had radiologic signs of JI, including intestinal fold thickening (57%), luminal narrowing (31%), and skip lesions (13%). Enteric fistula (6%) and strictures (6%) were less common. Patients with JI were likely to be stunted at the time of diagnosis, require surgical intervention (P < 0.03) and nutritional therapy in the form of nasogastric tube feeds (P < 0.03). Nutritional therapy was also associated with an improvement in height in patients with proximal small bowel disease (OR:5.87). DISCUSSION: JI is a relatively common disease phenotype in children with CD that requires aggressive nutritional and surgical intervention. Future studies are required to determine if the early detection and use of immune modulators may lessen the morbidity associated with proximal small bowel disease.


Assuntos
Doença de Crohn/complicações , Doença de Crohn/reabilitação , Ileíte/etiologia , Doenças do Jejuno/etiologia , Apoio Nutricional , Criança , Feminino , Humanos , Ileíte/terapia , Doenças do Jejuno/terapia , Masculino , Fenótipo , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
4.
Magn Reson Imaging ; 7(6): 689-91, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2630852

RESUMO

We present here the first report of an extraskeletal metastasizing presacral chordoma found in a child. MRI of this large lesion showed heterogeneous signal intensity on both the SE 550/30 and on SE 2440/100 images. MRI demonstrated this mass to be separate from the sacrum and provided nonionizing cross-sectional imaging prior to attempted surgical resection.


Assuntos
Cordoma/secundário , Neoplasias Pulmonares/secundário , Imageamento por Ressonância Magnética , Neoplasias Pélvicas/diagnóstico , Pré-Escolar , Cordoma/diagnóstico , Diagnóstico Diferencial , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Neoplasias Pélvicas/patologia , Tomografia Computadorizada por Raios X
5.
J Parasitol ; 86(3): 624-7, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10864267

RESUMO

Sarcocystis speeri Dubey and Lindsay, 1999 from the South American opossum Didelphis albiventris was successfully transmitted to the North American opossum Didelphis virginiana. Sporocysts from a naturally infected D. albiventris from Argentina were fed to 2 gamma-interferon knockout (KO) mice. The mice were killed 64 and 71 days after sporocyst feeding (DAF). Muscles containing sarcocysts from the KO mouse killed 71 DAF were fed to a captive D. virginiana; this opossum shed sporocysts 11 days after ingesting sarcocysts. Sporocysts from D. virginiana were fed to 9 KO mice and 4 budgerigars (Melopsittacus undulatus). Schizonts, sarcocysts, or both of S. speeri were found in tissues of all 7 KO mice killed 29-85 DAF; 2 mice died 39 and 48 DAF were not necropsied. Sarcocystis stages were not found in tissues of the 4 budgerigars fed S. speeri sporocysts and killed 35 DAE These results indicate that S. speeri is distinct from Sarcocystis falcatula and Sarcocystis neurona, and that S. speeri is present in both D. albiventris and D. virginiana.


Assuntos
Gambás/parasitologia , Sarcocystis/patogenicidade , Sarcocistose/veterinária , Animais , Argentina , Encéfalo/parasitologia , Fezes/parasitologia , Interferon gama/genética , Intestino Delgado/parasitologia , Fígado/parasitologia , Camundongos , Camundongos Knockout , Microscopia Eletrônica , Músculo Esquelético/parasitologia , América do Norte , Papagaios , Sarcocystis/ultraestrutura , Sarcocistose/transmissão
6.
Clin Imaging ; 24(4): 200-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11274882

RESUMO

The development of gastric carcinoid tumors is a rare but recognized complication of prolonged, severe hypergastrinemia. We present 2 patients with elevated gastrin levels who developed gastric carcinoid tumors and the CT findings are reviewed.


Assuntos
Tumor Carcinoide/diagnóstico por imagem , Gastrinas/sangue , Gastrite/complicações , Neoplasias Gástricas/diagnóstico por imagem , Síndrome de Zollinger-Ellison/complicações , Adulto , Tumor Carcinoide/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/etiologia , Tomografia Computadorizada por Raios X
7.
Clin Imaging ; 24(4): 204-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11274883

RESUMO

Despite the widespread use of laparoscopic cholecystectomy, technical complications unique to the laparoscopic approach may lead to significant postoperative morbidity and mortality. We report a rare case of small bowel perforation due to trocar injury that led to extensive pneumoperitoneum and pneumomediastinum in a patient who underwent laparoscopic cholecystectomy. Small bowel injuries should be suspected when a large or an increasing amount of free air is detected following this procedure.


Assuntos
Colecistectomia Laparoscópica/efeitos adversos , Colelitíase/cirurgia , Perfuração Intestinal/diagnóstico por imagem , Perfuração Intestinal/etiologia , Intestino Delgado/lesões , Adulto , Feminino , Humanos , Enfisema Mediastínico/diagnóstico por imagem , Enfisema Mediastínico/etiologia , Pneumoperitônio/diagnóstico por imagem , Pneumoperitônio/etiologia , Tomografia Computadorizada por Raios X
9.
Clin Imaging ; 23(4): 223-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10631898

RESUMO

Pulmonary sequestration is a malformation comprised of dysplastic lung tissue without normal communication with the tracheobronchial tree and with an anomalous systemic arterial supply. Pulmonary sequestration is classified into two types, intralobar and extralobar based on the location of the malformation and the venous drainage. Extralobar sequestration is less common than intralobar sequestration and usually has systemic venous drainage into the azygos system. Most patients with extralobar sequestration are diagnosed before the age of 10. We present an interesting and unusual case of extralobar sequestration which presented as a retroperitoneal mass in an asymptomatic adult.


Assuntos
Sequestro Broncopulmonar/diagnóstico por imagem , Sequestro Broncopulmonar/patologia , Tomografia Computadorizada por Raios X , Adulto , Sequestro Broncopulmonar/cirurgia , Meios de Contraste , Humanos , Masculino
13.
Radiographics ; 21(6): 1463-73, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11706217

RESUMO

Mesenteric ischemia is a complicated disorder whose prevalence in the United States is increasing as the population ages. It is often difficult to diagnose, both clinically and radiologically. In the past, computed tomography (CT) has allowed only limited success in the early detection of ischemia. However, with the introduction of multi-detector row CT and three-dimensional (3D) imaging, it is now possible to perform a detailed CT examination of the small bowel and mesenteric vessels. Multi-detector row CT allows routine studies to be performed much faster than with single-detector CT scanners and makes available new applications, especially in the field of CT angiography. Its increased speed and narrower collimation, coupled with the use of water as an oral contrast agent, improve visualization of the bowel wall and mesenteric vasculature. Multi-detector row CT with 3D reformatting may improve the ability to make an early diagnosis and identify the cause of disease in patients with suspected acute or chronic mesenteric ischemia. In many cases, this examination has eliminated the need for additional imaging studies such as Doppler ultrasonography or angiography. Further investigation will be needed to determine the scope of the utility of multi-detector row CT in this clinical setting.


Assuntos
Isquemia/diagnóstico por imagem , Mesentério/irrigação sanguínea , Mesentério/diagnóstico por imagem , Tomografia Computadorizada por Raios X/instrumentação , Doença Aguda , Doença Crônica , Humanos , Imageamento Tridimensional , Tomografia Computadorizada por Raios X/métodos
14.
Pancreatology ; 1(6): 610-24, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12120244

RESUMO

Over the past two decades, there have been significant technical advancements in computed tomography (CT). This has allowed CT to remain the gold standard for the evaluation of pancreatic pathology despite the advent of other imaging modalities, including MRI, PET and endoscopic ultrasound. Initially, CT scanners could only obtain 10-mm-thick slices at a rate of 4 slices per minute. Today, the current state of the art is multidetector CT (MDCT) technology, which allows the entire pancreas to be imaged by 1-mm slices in under 20 s. In addition, these new scanners allow true volume acquisition. The resultant data sets can be displayed not only as axial slices but also as a three-dimensional (3D) volume. The detail of these reconstructions when performed with volume rendering and maximum intensity projection techniques allows a detailed vascular mapping with accuracy that may exceed classic angiography. The use of thin collimation and dual-phase acquisition also improves the detection of hepatic metastasis as well as other sites of extrapancreatic disease. This article reviews the current state of the art of pancreatic imaging with specific emphasis on the use of MDCT, volume acquisitions and 3D arterial- and venous-phase vascular mapping. The advantages of these techniques and their impact on diagnosis and patient management are also addressed.


Assuntos
Angiografia/métodos , Neoplasias Pancreáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Humanos
15.
Abdom Imaging ; 23(4): 404-8, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9663277

RESUMO

The paraumbilical vein is a common venous collateral in patients with cirrhosis and portal hypertension. This pictorial essay demonstrates the use of computed tomographic angiography with three-dimensional volume rendering techniques to visualize the paraumbilical vein and its relationship to abdominal wall collaterals. The unique anatomy and embryology of this vessel is also discussed.


Assuntos
Angiografia/métodos , Cirrose Hepática/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Veias Umbilicais/diagnóstico por imagem , Músculos Abdominais/irrigação sanguínea , Circulação Colateral , Humanos , Veias Umbilicais/embriologia
16.
J Comput Assist Tomogr ; 24(1): 67-71, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10667662

RESUMO

PURPOSE: The purpose of this work was to determine normal contrast enhancement of the small bowel with biphasic spiral CT, using water as oral contrast agent. METHOD: Biphasic spiral CT was performed in 50 healthy patients undergoing evaluation as potential renal donors. All patients received 500 ml of water as oral contrast agent and 150 ml of Omnipaque 350 administered by mechanical injector at a rate of 3 ml/s. Dual phase CT of the abdomen was performed in each patient. Acquisition of early phase images began 30 s after the start of the intravenous injection, and portal phase images were obtained 60 s after initiation of the contrast agent injection. Attenuation measurements (in Hounsfield units) were obtained from the wall of the small bowel (duodenum, jejunum, ileum) in both the arterial and the portal phases. RESULTS: During the arterial phase, the mean (95% confidence interval) attenuation of the duodenum, jejunum, and ileum was 120 (+/- 5), 119 (+/- 5), and 118 (+/- 5) HU, respectively. During the portal phase, the average attenuation of the duodenum, jejunum, and ileum was 111 (+/- 4), 111 (+/- 3), and 107 (+/- 3) HU, respectively. There was no statistically significant difference between the attenuation of the duodenum, jejunum, or ileum within either the arterial or the portal venous phases. There was a statistically significant difference in small bowel enhancement between the arterial and portal venous phases. CONCLUSION: There is no important variation in small bowel attenuation during the 30 and 60 s scanning phases. This study serves as a normal reference that may be helpful when spiral CT is used to evaluate ischemic bowel or inflammatory small bowel diseases.


Assuntos
Duodeno/diagnóstico por imagem , Íleo/diagnóstico por imagem , Jejuno/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Administração Oral , Adulto , Meios de Contraste/administração & dosagem , Feminino , Humanos , Injeções Intravenosas , Iohexol/administração & dosagem , Masculino , Água/administração & dosagem
17.
Radiographics ; 20(2): 399-418, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10715339

RESUMO

Computed tomography (CT) is valuable for detection and characterization of many inflammatory conditions of the colon. At CT, a dilated, thickened appendix is suggestive of appendicitis. A 1-4-cm, oval, fatty pericolic lesion with surrounding mesenteric inflammation is diagnostic of epiploic appendagitis. The key to distinguishing diverticulitis from other inflammatory conditions of the colon is the presence of diverticula in the involved segment. In typhlitis, CT demonstrates cecal distention and circumferential thickening of the cecal wall, which may have low attenuation secondary to edema. In radiation colitis, the clinical history is the key to suggesting the diagnosis because the CT findings can be nonspecific. The location of the involved segment and the extent and appearance of wall thickening may help distinguish Crohn disease and ulcerative colitis. In ischemic colitis, CT typically demonstrates circumferential, symmetric wall thickening with fold enlargement. CT findings of graft-versus-host disease include small bowel and colonic wall thickening, which may result in luminal narrowing and separation of bowel loops. In infectious colitis, the site and thickness of colon affected may suggest a specific organism. The amount of wall thickening in pseudomembranous colitis is typically greater than in any other inflammatory disease of the colon except Crohn disease.


Assuntos
Colite/diagnóstico por imagem , Colo/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Apendicite/diagnóstico por imagem , Doenças do Ceco/diagnóstico por imagem , Colite/microbiologia , Colite Isquêmica/diagnóstico por imagem , Colite Ulcerativa/diagnóstico por imagem , Colo/efeitos da radiação , Doença de Crohn/diagnóstico por imagem , Doença Diverticular do Colo/diagnóstico por imagem , Divertículo do Colo/diagnóstico por imagem , Edema/diagnóstico por imagem , Enterocolite Pseudomembranosa/diagnóstico por imagem , Feminino , Doença Enxerto-Hospedeiro/diagnóstico por imagem , Humanos , Inflamação , Intestino Delgado/diagnóstico por imagem , Masculino , Mesentério/diagnóstico por imagem , Pessoa de Meia-Idade , Peritonite/diagnóstico por imagem , Lesões por Radiação/diagnóstico por imagem
18.
Radiographics ; 20(2): 419-30, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10715340

RESUMO

Colorectal cancer is a common malignancy that results in significant morbidity and mortality. Abdominal computed tomography (CT) is valuable in planning surgery for colon cancer because it can demonstrate regional extension of tumor as well as adenopathy and distant metastases. At CT, colorectal cancer typically appears as a discrete soft-tissue mass that narrows the colonic lumen. Colorectal cancer can also manifest as focal colonic wall thickening and luminal narrowing. Complications of primary colonic malignancies such as obstruction, perforation, and fistula can be readily visualized with CT. At CT, local extension of tumor appears as an extracolic mass or simply as thickening and infiltration of pericolic fat. Extracolic spread is also suggested by loss of fat planes between the colon and adjacent organs. The liver is the predominant organ to be involved with metastases from colorectal cancer. At CT, hepatic metastases usually appear as hypoattenuating masses, which are best visualized during the portal venous phase of liver enhancement. Other common sites of metastases from colon cancer include the lungs, adrenal glands, and bones. Use of CT is critical for identifying recurrences, evaluating anatomic relationships, documenting "normal" postoperative anatomy, and confirming the absence of new lesions during and after therapy.


Assuntos
Neoplasias do Colo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Planejamento de Assistência ao Paciente , Tomografia Computadorizada por Raios X/métodos , Tecido Adiposo/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Doenças do Colo/diagnóstico por imagem , Neoplasias do Colo/cirurgia , Feminino , Seguimentos , Humanos , Fístula Intestinal/diagnóstico por imagem , Obstrução Intestinal/diagnóstico por imagem , Perfuração Intestinal/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/secundário , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia/diagnóstico por imagem , Estadiamento de Neoplasias , Intensificação de Imagem Radiográfica
19.
J Comput Assist Tomogr ; 24(6): 849-53, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11105699

RESUMO

Multidetector CT (MDCT) provides unparalleled capabilities for combining narrow scan collimation with rapid data acquisition protocols. When combined with CT angiographic techniques and 3D-volume rendering we are able to create unique displays for evaluating a range of clinical pathologies. In this pictorial review we present the potential advantages of using MDCT angiography for the evaluation of pancreatic cancer and its role in the accurate staging of these patients. The use of dual-phase CT scanning in both the arterial phase and portal phase is addressed with the role of 3D CT angiography clearly defined. Numerous case studies are presented to show the advantages of these techniques over simple axial CT imaging.


Assuntos
Angiografia/métodos , Carcinoma/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Angiografia/instrumentação , Artérias , Artéria Celíaca/diagnóstico por imagem , Apresentação de Dados , Feminino , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Masculino , Artéria Mesentérica Superior/diagnóstico por imagem , Veias Mesentéricas/diagnóstico por imagem , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Pâncreas/irrigação sanguínea , Veia Porta/diagnóstico por imagem , Veia Esplênica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/instrumentação , Interface Usuário-Computador
20.
J Digit Imaging ; 13(1): 46-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10696601

RESUMO

The purposes of this study were to determine what percentage of patients in a typical radiology outpatient setting own or have access to a computer with internet capabilities and how many of these patients would find an educational radiology website useful. During a 3-month period, surveys were given to all adult outpatients undergoing computed tomography. The survey asked 4 questions: (1) Do you own a computer?, (2) If you own a computer, does it have Internet access?, (3) If you do not own a computer, do you have access to a computer with Internet capabilities?, and (4) If we provide helpful information regarding preparation for and the conduct of various radiological procedures on the Internet, would you use it? Four hundred surveys were collected. Two hundred one of the respondents (50.3%) owned a computer; 189 of the 201 (94.0%) had Internet access on their computer or had access to another computer with Internet capabilities. One hundred ninety-nine of the 400 respondents (49.8%) did not own a computer, 57 of these (28.6%) had access to a computer and the Internet. Of the 246 of those with Internet access, 205 (83.3%) indicated that they would use a website that provided helpful information regarding radiological examinations. The Internet is an excellent resource for educational information for patients about various radiological procedures. This study showed that 61.5% of patients had access to the Internet, and 83.3% of these would use such a site. It is likely that these numbers will increase with the rapid growth of the Internet and the steadily increasing number of homes with computers.


Assuntos
Internet , Educação de Pacientes como Assunto , Radiologia , Adulto , Humanos , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa