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1.
Clin Radiol ; 69(3): 246-53, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24295735

RESUMO

AIM: To assess the feasibility of a fast single-bolus combined carotid and coronary computed tomography angiography (CTA) protocol in asymptomatic patients. MATERIALS AND METHODS: Thirty-three consecutive patients (18 women and 15 men) with a median age of 61 ± 14 years old (range 37-87 years) with known or suspected atherosclerotic disease were enrolled in this prospective study. A single breath-hold, single biphasic injection protocol (50 ml at 3 ml/s, 50 ml at 5 ml/s, 50 ml saline flush at 5 ml/s) was used for combined CTA imaging of the supra-aortic (SAA) and coronary arteries (CA) on a 64-slice dual-source CT (DSCT) machine. Helical CTA acquisition of the SAA was followed by prospective electrocardiography (ECG)-triggered coronary CTA. Subjective (four-point scale) image quality and objective signal-to-noise (SNR) and contrast-to-noise (CNR) measurements were performed. Vascular disease was graded on a four-point scale (grade 1: absent; grade 2: mild, grade 3: moderate; grade 4: severe). The radiation dose was recorded for each patient. RESULTS: The average enhancement and subjective quality score of SAA and CA segments were 396 HU/358 HU and 1.2 ± 0.3/1.72 ± 0.4, respectively. The SNR was 27.1 ± 1.7 in the SAA and 21.6 ± 1.6 in the CA (p < 0.0001). The CNR was 18.1 ± 1.2 and 15.9 ± 1.8, respectively (p = 0.4). Four percent of SAA and 14% of CA segments (mostly due to peri-venous streak artefacts and small calibre, respectively) produced non-diagnostic images. SAA findings were as follows: 26/33 (79%) patients showed no disease and 6/33 (18%) had grade 2 and 1/33 (3%) had grade 3 disease. CA findings were as follows: 25/33 (76%) showed no disease and 6/33 (18%) patients had grade 2 and 2/33 (6%) had grade 3 disease. Five patients had disease in both districts. The average radiation dose for the combined CTA angiogram was 4.3 ± 0.6 mSv. CONCLUSION: A fast, low-dose combined DSCT angiography protocol appears technically feasible for imaging carotid and coronary atherosclerotic disease.


Assuntos
Angiografia/métodos , Doenças das Artérias Carótidas/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Tomografia Computadorizada Espiral , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Imagem de Sincronização Cardíaca , Meios de Contraste , Estudos de Viabilidade , Feminino , Humanos , Iopamidol , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador
2.
Clin Radiol ; 68(3): e154-63, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23276388

RESUMO

AIM: To assess the diagnostic value of coronary dual-source computed tomography (DSCT) as a comprehensive, non-invasive tool in the preoperative cardiac evaluation of patients undergoing bariatric surgery. MATERIALS AND METHODS: Thirty consecutive obese [average body mass index (BMI): 45 ± 7.6, range: 35-59] patients (24 women; six men; median age: 52 ± 15 years) were enrolled in this institutional review board (IRB)-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant prospective study. Calcium scoring (CaS) and electrocardiography (ECG)-gated images of the coronary arteries were obtained with a large body habitus protocol (120 kV; 430 mAs; 100 ml iodinated contrast medium at 7 ml/s injection rate) on a DSCT machine. Qualitative (four-point: 1 = excellent to 4 = not delineable) coronary segmental analysis, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) measurements were performed. The presence and degree of vascular disease (four-grade scale: mild to severe) was correlated with CaS and cardiovascular (CV) risk stratification blood tests. In patients with severe stenosis (>70%), findings were compared with cardiac nuclear medicine imaging (single photon-emission computed tomography; SPECT) imaging. RESULTS: The average HR, enhancement, and quality score were 64 ± 7 beats/min, 288 ± 66 HU and 1.8 ± .5, respectively. Ninety-three percent (417/450) of the coronary segments were rated diagnostic. The SNRs and CNRs were 17 ± 9 and 12 ± 7 for the right coronary artery; 17 ± 8 and 12 ± 7 for the left main coronary artery; 16 ± 9 and 11 ± 7 for the left anterior descending coronary artery; and 15 ± 7 and 10 ± 6 for the left circumflex coronary artery. Ten of the 30 patients (33%) demonstrated coronary artery disease (CAD) of which two (6%) showed three-vessel disease. Four (13%) patients showed severe disease: in three of which the presence of significant stenosis was confirmed by SPECT and by catheter angiography in the fourth patient. Neither the CaS, nor the CV risk stratification tests showed significant correlation with presence or degree of CAD (p > 0.05). CONCLUSIONS: Coronary DSCT is a robust alternative imaging tool in the preoperative assessment of patients undergoing bariatric surgery.


Assuntos
Cirurgia Bariátrica , Doenças Cardiovasculares/diagnóstico por imagem , Cuidados Pré-Operatórios , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Meios de Contraste , Eletrocardiografia , Feminino , Humanos , Iopamidol , Pessoa de Meia-Idade , Estudos Prospectivos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Fatores de Risco , Tomografia Computadorizada de Emissão de Fóton Único
3.
Cardiovasc Intervent Radiol ; 42(3): 460-465, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30603971

RESUMO

PURPOSE: To report technical success and clinical outcomes of transfemoral venous access for upper extremity dialysis interventions. MATERIALS AND METHODS: A total of 15 patients underwent a transfemoral venous approach for fistulography (n = 4; 27%) or thrombectomy (n = 11; 73%) over a 14-month period. Access characteristics, sheath size, thrombectomy method, angioplasty site, fluoroscopy time, radiation dose, technical and clinical success, complications, and post-intervention primary and secondary patency rates were recorded. RESULTS: Access type included arteriovenous fistulas (n = 10; 67%) and grafts (n = 5; 33%). The most common configuration was brachio-brachial (n = 6; 38%). Mean age of access was 37 months. Mean prior interventions were 4. Right CFV access was used in all patients using 6-8-French (most common: 7-French [n = 10; 67%]) sheaths. Most thrombectomies (n = 11; 73%) required both pharmacologic and mechanical maceration (n = 9; 82%). All accesses required angioplasty to treat underlying stenosis at the outflow vein (n = 12; 80%) or arteriovenous anastomosis (n = 9; 90%). Mean fluoroscopy time was 26.43 min. Air kerma and dose area product were 178.06 ± 225.77 mGy and 57,768.83 ± 87,553.29 µGym2, respectively. Procedural and clinical success rates were 93% and 80%, respectively. Technical failure was due to persistent stenosis in one patient. Clinical failure was due to unsuccessful dialysis immediately following intervention in three patients. Mean post-intervention primary patency and secondary patency durations were 2.8 and 4.8 months, respectively. Primary patency rates at 1 and 3 months were 50% and 35%, respectively. Secondary patency rates at 1 and 3 months were 58% and 30%, respectively. CONCLUSION: A transfemoral venous approach for intervention of upper extremity dialysis accesses may be a valuable adjunct to traditional approaches.


Assuntos
Derivação Arteriovenosa Cirúrgica/métodos , Procedimentos Endovasculares/métodos , Veia Femoral , Diálise Renal/métodos , Extremidade Superior/irrigação sanguínea , Grau de Desobstrução Vascular/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
4.
AJNR Am J Neuroradiol ; 28(7): 1362-8, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17698541

RESUMO

BACKGROUND AND PURPOSE: Bone-subtraction techniques have been shown to enhance CT angiography (CTA) interpretation, but motion can lead to incomplete bone removal. The aim of this study was to evaluate 2 novel registration techniques to compensate for patient motion. MATERIALS AND METHODS: Fifty-four patients underwent bone-subtraction CTA (BSCTA) for the evaluation of the neck vessels with 64-section CT. We tested 3 different registration procedures: pure rigid registration (BSCTA), slab-based registration (SB-BSCTA), and a partially rigid registration (PR-BSCTA) approach. Subtraction quality for the assessment of different vascular segments was evaluated by 2 examiners in a blinded fashion. The Cohen kappa test was applied for interobserver variability, and the Wilcoxon signed rank test, for differences between the procedures. Motion between the corresponding datasets was measured and plotted against image-quality scores. RESULTS: Algorithms with motion compensation revealed higher image-quality scores (SB-BSCTA, mean 4.31; PR-BSCTA, mean 4.43) than pure rigid registration (BSCTA, mean 3.88). PR-BSCTA was rated superior to SB-BSCTA for the evaluation of the cervical internal and external carotid arteries (P<.001), whereas there was no significant difference for the other vessels (P=.157-.655). Both algorithms were clearly superior to pure rigid registration for all vessels except the basilar and ophthalmic artery. Interobserver agreement was high (kappa=0.46-0.98). CONCLUSION: Bone-subtraction algorithms with motion compensation provided higher image-quality scores than pure rigid registration methods, especially in cases with complex motion. PR-BSCTA was rated superior to SB-BSCTA in the visualization of the internal and external carotid arteries.


Assuntos
Artefatos , Osso e Ossos/diagnóstico por imagem , Angiografia Cerebral/métodos , Aumento da Imagem/métodos , Técnica de Subtração , Tomografia Computadorizada por Raios X/métodos , Cabeça/irrigação sanguínea , Cabeça/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Movimento (Física) , Pescoço/irrigação sanguínea , Pescoço/diagnóstico por imagem , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Circulation ; 99(22): 2921-6, 1999 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-10359737

RESUMO

BACKGROUND: Detection of myocardial viability is important in patients with ischemic cardiomyopathy. Restoration of blood flow to viable myocardium is associated with improved left ventricular function and improved patient prognosis. However, the prevalence of viable myocardium in patients with ischemic cardiomyopathy is unknown. METHODS AND RESULTS: To determine the prevalence of myocardial viability, clinical [13N]ammonia/18F-deoxyglucose PET studies performed in 283 patients (age, 63+/-10 years) with ischemic heart disease (mean ejection fraction, 26+/-8%) were visually analyzed for the presence and extent of viable and nonviable myocardium. The myocardium was divided into 19 segments. The extent of viable myocardium was considered "functionally" significant if >/=5 segments ( approximately 25% of the left ventricular myocardium) exhibited a blood flow/metabolism mismatch and "prognostically" significant if 1 to 4 left ventricular segments did so. Of all patients, 41% had no evidence of viable myocardium, 55% had viable myocardium, and 4% had normal blood flow and metabolism within an enlarged left ventricle. Functionally significant viability was found in 27% and prognostically significant viability in 28% of the patients. Multivariate analysis revealed the presence of angina to be the only clinical parameter associated with the presence of functionally significant viability. CONCLUSIONS: Revascularization might improve patient prognosis in 55% and result in improved left ventricular function in 27% of all patients with ischemic cardiomyopathy.


Assuntos
Coração/diagnóstico por imagem , Coração/fisiopatologia , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Tomografia Computadorizada de Emissão , Idoso , Circulação Coronária , Feminino , Transplante de Coração , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/tratamento farmacológico , Isquemia Miocárdica/cirurgia , Revascularização Miocárdica , Sobrevivência de Tecidos
6.
J Bone Miner Res ; 10(2): 250-6, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7754804

RESUMO

Although corticosteroid therapy is associated with the development of osteopenia, it is unclear whether the cause of osteopenia in inflammatory bowel disease (Crohn's disease and ulcerative colitis) is related to corticosteroid therapy or other disease-related variables. Patients with Crohn's disease (a diffuse gastrointestinal disease) could have greater osteopenia than patients with ulcerative colitis because of small bowel disease and secondary malabsorption of calcium and vitamin D. A cross-sectional analysis of consecutive patients with Crohn's disease and ulcerative colitis was undertaken. Bone density was determined by measurements of the L2-L4 spine, the total hip, and Ward's triangle using dual energy X-ray absorptiometry (DXA). A number of clinical parameters were recorded prior to bone density evaluation and analyzed by univariate and subsequently multivariate analysis to determine possible predictors of osteopenia. Of the 26 patients with Crohn's disease, diminished bone density (a Z score of at least -1) was found at the hip in 64% and at the spine in 44%; and of the 23 patients with ulcerative colitis diminished bone density was found at the hip in 43% and at the spine in 48%. Among all the variables tested, only corticosteroid use was a statistically significant predictor of diminished bone density (p = 0.025 for the spine and hip and p = 0.005 for Ward's triangle). Disease diagnosis (Crohn's disease compared with ulcerative colitis) did not predict or correlate with diminished bone density. No obvious associations were seen between the measurements of any serum hormones or biochemistries and bone density, although the patients using corticosteroids had lower serum calcium levels than the nonusers.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Corticosteroides/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/induzido quimicamente , Colite Ulcerativa/fisiopatologia , Doença de Crohn/fisiopatologia , Absorciometria de Fóton , Corticosteroides/administração & dosagem , Corticosteroides/uso terapêutico , Adulto , Análise de Variância , Densidade Óssea/fisiologia , Doenças Ósseas Metabólicas/etiologia , Cálcio/metabolismo , Colite Ulcerativa/complicações , Colite Ulcerativa/tratamento farmacológico , Doença de Crohn/complicações , Doença de Crohn/tratamento farmacológico , Estudos Transversais , Feminino , Quadril/fisiologia , Humanos , Absorção Intestinal/efeitos dos fármacos , Vértebras Lombares/efeitos dos fármacos , Vértebras Lombares/fisiologia , Masculino , Pessoa de Meia-Idade , Vitamina D/metabolismo
7.
AIDS Res Hum Retroviruses ; 17(15): 1423-33, 2001 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-11679155

RESUMO

HIV-1 cardiomyopathy has become a major cause of death in AIDS patients, but its pathogenesis is unclear. We used an antigen retrieval technique and immunostaining to investigate the hearts of 15 AIDS patients, of whom 3 had dilated cardiomyopathy. Immunocytochemistry shows infiltration of the left ventricular myocardium with mononuclear cells, ranging from minimal to diagnostic of myocarditis. The infiltrates include macrophages and CD3(+) and CD8(+) T cells. The tight junction protein ZO-1 is disrupted at the site of monocyte-macrophage vascular penetration and the coronary vessels show fibrinogen leakage in the hearts of AIDS patients, but not in the normal heart. A subset of infiltrating macrophages is doubly positive for cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase. HIV-1 peptides gp120 and Nef are expressed in macrophages and T cells, but not in cardiomyocytes. COX-2 is expressed by both gp120-positive and gp120-negative macrophages. The hearts of AIDS patients separate into those showing minimal infiltrates with low COX-2 expression and those with dense infiltrates and high COX-2; all failing hearts are in the latter group. These data suggest that COX-2-activated and HIV-1-infected monocyte-macrophages and T cells play a crucial role in the progression of HIV-1 myocarditis to HIV-1 cardiomyopathy.


Assuntos
Infecções por HIV/enzimologia , HIV-1/fisiologia , Isoenzimas/fisiologia , Ativação Linfocitária/imunologia , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Miocardite/imunologia , Prostaglandina-Endoperóxido Sintases/fisiologia , Linfócitos T/imunologia , Disfunção Ventricular Esquerda/imunologia , Encéfalo/imunologia , Vasos Coronários/imunologia , Ciclo-Oxigenase 2 , Infecções por HIV/complicações , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Isoenzimas/metabolismo , Rim/imunologia , Leucócitos/imunologia , Fígado/imunologia , Macrófagos/virologia , Proteínas de Membrana , Miocardite/complicações , Miocardite/enzimologia , Miocardite/virologia , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Prostaglandina-Endoperóxido Sintases/metabolismo , Linfócitos T/virologia , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/enzimologia , Disfunção Ventricular Esquerda/virologia
8.
Environ Health Perspect ; 29: 179-82, 1979 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-510237

RESUMO

House dust has been suspected as a source of lead in the exposure of children, particularly those whose blood lead levels are in the moderately elevated range. The means by which household surface lead accumulates is at present not clear. By towel wipe sampling, 24 vacant houses in urban Rochester and Buffalo, New York, were examined for lead content on windowsills, floors, and other surfaces. High yields of lead were obtained from windowsills and floor areas adjacent windows. When washed and resampled, these areas yielded greatly reduced lead values. It is suggested that surface lead may represent a deposit phenomenon. The entry of exterior airborne particulate lead around the loose-fitting windows of older homes appears possible.


Assuntos
Poeira , Habitação , Chumbo , Poeira/análise , Poluentes Ambientais , Zeladoria , Chumbo/análise , New York
9.
Environ Health Perspect ; 7: 91-7, 1974 May.
Artigo em Inglês | MEDLINE | ID: mdl-4831153

RESUMO

A method has been developed to test the hypothesis that lead-containing house dust is responsible for the elevated levels of lead in blood of inner city children. Dust analyses of smears from the floors, walls, and windowsills in low-income inner city dwellings have shown a median concentration of lead five times as high in suburban homes. It is suggested that lead-containing dust may be one of the most important environmental sources of increased lead exposure in this specific population group.


Assuntos
Poeira/análise , Habitação , Chumbo/análise , Criança , Pré-Escolar , Exposição Ambiental , Mãos , Humanos , Lactente , Intoxicação por Chumbo/etiologia , Pintura , Polarografia , População Urbana
10.
Chest ; 92(4): 594-603, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3652745

RESUMO

Two cohorts of never-smoking residents of Los Angeles were studied on two occasions five years apart. One cohort (N = 1,099) lived in a community with moderate levels of photochemical pollution and low levels of other pollutants, and the second (N = 1,117) lived in a community with very high levels of photochemical oxidant and relatively high levels of sulfates and particulates. Studies included measurement of forced expiratory volumes and flow rates and single-breath nitrogen washout, as well as use of a standardized questionnaire. The data represent 47 percent of 2,340 and 58 percent of 1,935 residents, respectively, of the original community samples. Mean baseline spirometry and nitrogen washout for those who were and those who were not retested were similar, reflecting the fact that loss to follow-up was primarily due to changes of residence. In the more polluted area there were significantly worse lung function test results for both men and women at baseline and significantly more rapid deterioration at follow-up. Mean changes in nitrogen washout were significantly greater in the more polluted community for both sexes and for all age groups including children. Most of the spirometric test results showed significantly more rapid decline among adults in the more polluted community. These results are consistent with the hypothesis that chronic exposures to a mix of photochemical oxidants, sulfates and particulates are associated with increased loss of lung function, which is especially marked among tests that reflect function of the small airways.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Pneumopatias Obstrutivas/fisiopatologia , Pulmão/fisiopatologia , Adolescente , Adulto , California , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxidantes Fotoquímicos/efeitos adversos , Óxidos/efeitos adversos , Testes de Função Respiratória , Sulfatos/efeitos adversos , População Urbana
11.
Chest ; 82(5): 630-8, 1982 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7128229

RESUMO

The relative sensitivity and specificity of symptoms, spirometry, the flow-volume (FV) curve, the single-breath nitrogen test (SBNT), and specific airway conductance (SGaw) were estimated by cross comparison of these tests with the FEV1/FVC ratio and other tests in 1,201 residents of Los Angeles. Spirometry and the flow-volume curve were estimated to be the most sensitive, yet reasonably specific composite measures, and FEV1/FVC and V75 to be the most sensitive individual indices. Among current smokers, FEV1/FVC was more frequently abnormal (23 percent) than FEF25-75% (16 percent), showed higher concordance with an abnormal FEF25-75% (88 percent), and identified a greater percentage of individuals as abnormal when the FEF25-75% was normal (9 percent) than vice versa. SGaw and SBNT showed a poor concordance with FEV1/FVC and identified more individuals as abnormal who had a normal FEV1/FVC. Although the proportion of current smokers with productive cough was relatively high (26 percent), none of the function tests showed a reasonable concordance with this symptom. These findings suggest that: 1) spirometry, the flow-volume curve, V75 and FEV1/FVC are relatively sensitive and specific indicators of respiratory impairment; 2) spirometry and the FV curve provide similar but not completely overlapping information; 3) SGaw and SBNT yield different (or less specific) information than the other tests; and 4) effects of cigarette smoking identified by productive cough are different from those identified by other tests.


Assuntos
Pneumopatias Obstrutivas/diagnóstico , Testes de Função Respiratória , Adulto , Volume de Oclusão , Estudos de Avaliação como Assunto , Feminino , Fluxo Expiratório Forçado , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Fumar , Capacidade Vital
12.
Invest Radiol ; 29(10): 928-32, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7852045

RESUMO

The precision of a measurement can be expressed as the variance of multiple measurements. The coefficient of variation is a dimensionless expression of precision that is prevalent in the radiology literature. However, the coefficient of variation has important limitations. The question whether measured change is significant arises whenever any quantitative clinical parameter is followed over time. When serial bone mineral density measurements are made, change is commonly estimated as the slope of a line fitted to the serial data by linear regression. Confidence intervals for change based on this method usually assume that the precision error in measurement remains constant over time and that change is truly linear. Estimates of long-term precision may be elusive, and if constant, may vary for different individuals. If separate measurement precisions are known or are indeed constant, one can assess the level of statistical agreement of longitudinal data to linear, or other theoretical, models.


Assuntos
Absorciometria de Fóton/estatística & dados numéricos , Densidade Óssea/fisiologia , Algoritmos , Viés , Densidade Óssea/efeitos dos fármacos , Intervalos de Confiança , Interpretação Estatística de Dados , Terapia de Reposição de Estrogênios , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Modelos Estatísticos , Ossos Pélvicos/efeitos dos fármacos , Ossos Pélvicos/fisiologia , Análise de Regressão , Reprodutibilidade dos Testes
13.
Invest Radiol ; 28(5): 398-403, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8496031

RESUMO

RATIONALE AND OBJECTIVES: Digital image compression reduces the storage requirements and network traffic on picture archiving and communications systems. Full-frame bit-allocation (FFBA) is an irreversible image-compression method based on the discrete cosine transform that provides for high compression ratios with a high degree of image fidelity. METHODS: One hundred twenty-two posteroanterior chest radiographs were obtained on patients in an ambulatory patient setting, including 30 cases of interstitial lung disease, 45 images containing combinations of lung nodules (N = 37) or mediastinal masses (N = 39), and 47 normal images containing none of the pathology for which we were testing. The images were digitized (nominal 2 K x 2 K x 12-bit resolution), printed on a 35 x 35-cm hard copy format, and compressed at an approximate compression ratio of 20:1. Observer performance tests were conducted with five radiologists using receiver operating characteristics analysis on digitized uncompressed and compressed hard copy images. RESULTS: There were no significant differences between the two display conditions for the detectability of any of the thoracic abnormalities. CONCLUSIONS: Our preliminary results suggest that irreversible image compression at ratios of 20:1 may be acceptable for use in digital thoracic imaging.


Assuntos
Doenças do Mediastino/diagnóstico por imagem , Fibrose Pulmonar/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Nódulo Pulmonar Solitário/diagnóstico por imagem , Algoritmos , Humanos , Doenças do Mediastino/epidemiologia , Fibrose Pulmonar/epidemiologia , Curva ROC , Radiografia Torácica/métodos , Sistemas de Informação em Radiologia , Nódulo Pulmonar Solitário/epidemiologia
14.
Int J Epidemiol ; 11(4): 323-8, 1982 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7152785

RESUMO

The purpose of this paper is to estimate the validity of current diagnostic procedures used in Santiago, Chile, in identifying gastric cancer (GC) patients among people with gastric complaints, many of whom suffer possible premalignant conditions. Review of diagnoses on 2296 patients seen at the University Hospital during 1976 and 1977 revealed 103 confirmed cases of adenocarcinoma. This review permitted us to estimate the validity of clinical/radiological and endoscopic methods versus diagnosis made from pathological specimens. A code of diagnostic categories was generated for application in eight hospitals participating in a subsequent case-control study of GC. A high prevalence of chronic atrophic gastritic (CAG) and chronic gastric ulcer (CGU) was found, both conditions together accounting for 50% of diagnoses on 845 clinic controls during the study period 1977-8. The value of gastroscopy and biopsy to separate out GC from other gastric conditions, the importance of studying the epidemiology of premalignant conditions in Chile, and differences between GC in Chile and the United States are discussed.


Assuntos
Neoplasias Gástricas/epidemiologia , Biópsia , Chile , Diagnóstico Diferencial , Métodos Epidemiológicos , Mucosa Gástrica/patologia , Gastroscopia , Humanos , Lesões Pré-Cancerosas/patologia , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/patologia , Estados Unidos
15.
Int J Epidemiol ; 10(1): 53-6, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7239763

RESUMO

The results of a case-control study of stomach cancer carried out with the collaboration of 7 participating hospitals in Santiago, Chile are reported. Patients attending gastroscopy clinics were interviewed before or after gastroscopy. The diagnosis was unknown to either the patient or the interviewer at the time of interview. 360 stomach cancer cases were subsequently matched to non-cancer patients selected from the pool interviewed at the same time as the cases. Study findings show: 1) longer-term residence in high-risk areas in early life by cases than controls; 2) an association between stomach cancer and a prior occupation in agriculture. In a subgroup of 98 cases for whom histologic classification was available, the association with residence in early life in a high-risk area was seen only for cases with intestinal-type stomach cancer.


Assuntos
Neoplasias Gástricas/epidemiologia , Adulto , Idoso , Doenças dos Trabalhadores Agrícolas/epidemiologia , Chile , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Fumar
16.
Int J Epidemiol ; 10(1): 57-62, 1981 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7239764

RESUMO

Nitrate levels in urine and nitrite levels in saliva were determined in school children 11-13 years of age in 2 areas of high stomach cancer mortality located in central Chile and in 2 areas of low stomach cancer mortality located at the extremes of Chile. Levels of both nitrates and nitrites were concurrently determined in selected vegetables obtained in these 4 study areas. Levels of nitrates were significantly higher in the urine of schoolchildren and in vegetables obtained from the northern low-risk area. Levels of nitrites were similar in saliva specimens from all 4 areas, but levels in vegetables were inconsistent. These results are apparently incompatible with the hypothesis of a high nitrate intake in areas of high stomach cancer incidence compared to areas of low incidence. This paradoxical finding suggests that cofactors may be involved in the pathopoiesis of stomach cancer that promote or inhibit the transformation of dietary nitrates to nitrosamines. The soil in the high-risk areas is primarily of volcanic origin, which is reported to be low in levels of selenium. On the other hand, residents of Antofagasta, the northern low-risk area, are known to be exposed to high levels of arsenic. It is possible that the diet of residents of the high incidence area which may be deficient in selenium may enhance promotion of nitrates to nitrosamines as has been reported in the literature, or conversely, that high levels of arsenic or other factors in the diet of individuals in Antofagasta may play a protective role. Other factors may be responsible for the low rate observed in the southern low-risk area.


Assuntos
Nitratos/análise , Nitritos/análise , Neoplasias Gástricas/epidemiologia , Adolescente , Líquidos Corporais/análise , Criança , Chile , Epidemiologia , Feminino , Humanos , Masculino , Risco , Solo , Neoplasias Gástricas/induzido quimicamente , Verduras/efeitos adversos
17.
Radiat Res ; 155(5): 740-3, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11302772

RESUMO

Norman, A., Cochran, S. T. and Sayre, J. W. Meta-analysis of Increases in Micronuclei in Peripheral Blood Lymphocytes after Angiography or Excretory Urography. Radiat. Res. 155, 740-743 (2001). Meta-analysis of 10 studies confirms a significant increase in the frequency of micronuclei in peripheral blood lymphocytes after angiography or excretory urography; the weighted average increase is 4.2 (95% confidence interval 2.8-5.6) per 1000 binucleate lymphocytes, about the same increase in micronuclei as that produced in vitro by a diagnostic X-ray dose of 4 cGy. The analysis failed to reveal a significant effect of the specific contrast medium used in the X-ray examinations on the increased frequency of micronuclei. These results are consistent with the hypothesis that the effect of the contrast media is limited to the enhancement, by the photoelectric effect, of the X-ray dose absorbed by the lymphocytes irradiated while suspended in the contrast medium. Therefore, an estimate of increased cancer risk based on elevated frequencies of micronuclei or chromosome aberrations in peripheral blood lymphocytes may be greatly exaggerated whenever the radiation damage is largely confined to the cells circulating in the blood, as it is in people who have recently had X-ray examinations that use intravenous injections of contrast medium. Such examinations include angiography, excretory urography and CT scans, which are received annually by millions of people.


Assuntos
Angiografia/efeitos adversos , Linfócitos/efeitos da radiação , Micronúcleos com Defeito Cromossômico/efeitos da radiação , Urografia/efeitos adversos , Aberrações Cromossômicas , Meios de Contraste/efeitos adversos , Humanos , Linfócitos/ultraestrutura
18.
Obstet Gynecol ; 89(2): 281-5, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9015036

RESUMO

OBJECTIVE: To identify variables that increase the chance of neonatal scalp injury during vacuum extraction. METHODS: We conducted a prospective observational study of 134 vacuum extraction-assisted deliveries at Olive View-UCLA Medical Center in 1995. Data collected included parity, gestational age, duration of first and second stages of labor, indication for operative delivery, station and position of fetal head, duration of vacuum application, number of "pop-offs," neonatal weight, and descriptions of scalp marks or injury. Cranial imaging studies were obtained if clinically indicated. RESULTS: There were 28 infants with scalp trauma, including 17 superficial lacerations, six large caputs, and 12 cephalohematomata; one infant had subgaleal, subdural, and subarachnoid hemorrhages. Logistic regression analysis showed duration of vacuum application to be the best predictor of scalp injury, followed by duration of second stage of labor and paramedian cup placement. Duration of vacuum application ranged from 0.5 to 26 minutes, with a median length of 3 minutes. The proportion of injuries was greater for applications exceeding 10 minutes (6 of 9) than for those 10 minutes or shorter (22 of 121, P < .01). We did not encounter any cases of clinically important scalp injury. CONCLUSIONS: Cosmetic scalp trauma occurred in 21% of our newborns delivered by vacuum extraction and was more common after longer vacuum applications, longer second stages, and paramedian cup placement.


Assuntos
Traumatismos do Nascimento/etiologia , Couro Cabeludo/lesões , Vácuo-Extração/efeitos adversos , Adolescente , Adulto , Traumatismos do Nascimento/epidemiologia , Feminino , Humanos , Incidência , Recém-Nascido , Modelos Logísticos , Pessoa de Meia-Idade , Gravidez , Estudos Prospectivos , Fatores de Tempo , Vácuo-Extração/métodos
19.
Obstet Gynecol ; 87(6): 1009-13, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8649681

RESUMO

OBJECTIVE: To compare laparoscope-assisted transvaginal removal of dermoid cysts to more standard laparoscopic cystectomy techniques. METHODS: We conducted a retrospective review of 44 laparoscopic dermoid removals performed at Olive View-UCLA Medical Center between 1992 and 1995. Cases were divided into three groups based on surgical approach: 1) conventional laparoscopic ovarian cystectomy, 2) laparoscopic ovarian cystectomy and removal of the freed mass via colpotomy, and 3) laparoscopic inspection, then transvaginal cystectomy via colpotomy. Surgical time, estimated blood loss, cyst spillage, and complications were compared. RESULTS: There were 11-19 patients in each group. The groups were similar in patient age, parity, and weight. Larger cysts tended to be removed by the laparoscopy-colpotomy techniques (mean diameter 10 cm) rather than by the purely laparoscopic approach (mean diameter 7 cm, P < .05). Cyst spillage occurred less often (43%, P < .05) and surgical time was shortest (mean 81 minutes, P < .05) with laparoscope-assisted transvaginal ovarian cystectomy compared with conventional laparoscopic techniques. Disposable laparoscopic instruments were used less often with transvaginal cystectomy (7%) than with conventional laparoscopic cystectomy (77%, P < .01). The difference in mean estimated blood loss in the cases using colpotomy (89 mL) compared with cases that did not (65 mL) was not statistically significant. Among the three groups, there were four major operative complications related to blood loss and infection. CONCLUSION: Laparoscope-assisted transvaginal ovarian cystectomy allows the removal of larger dermoid cysts, with less cyst spillage and savings in operative time and equipment compared with conventional laparoscopic cystectomy.


Assuntos
Cisto Dermoide/cirurgia , Laparoscopia/métodos , Cistos Ovarianos/cirurgia , Adulto , Cisto Dermoide/patologia , Feminino , Humanos , Complicações Intraoperatórias , Métodos , Cistos Ovarianos/patologia , Complicações Pós-Operatórias , Estudos Retrospectivos , Vagina/cirurgia
20.
AJNR Am J Neuroradiol ; 15(9): 1601-5, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7847201

RESUMO

PURPOSE: To report the comprehensive superselective angiographic characteristics of aneurysms associated with cerebral arteriovenous malformations. METHOD: One hundred consecutive patients referred for cerebral arteriovenous malformation embolization underwent preembolization superselective angiography. Superselective angiograms were obtained after microcatheterization of arteriovenous malformation pedicles, and assessed for number and location of aneurysms related to the malformation. A chi 2 test was conducted to correlate these parameters with the onset of intracranial hemorrhage. RESULTS: Aneurysms were demonstrated in 58 of 100 patients. Single aneurysms were found in 24 patients and multiple aneurysms in 34. Presence and number of aneurysms were found to correlate significantly with a clinical presentation of hemorrhage. CONCLUSION: Superselective angiography was found to be of paramount importance in elucidating the precise and detailed angioarchitecture of brain arteriovenous malformations.


Assuntos
Angiografia Cerebral/métodos , Aneurisma Intracraniano/congênito , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/terapia , Criança , Embolização Terapêutica , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/terapia , Malformações Arteriovenosas Intracranianas/terapia , Masculino , Pessoa de Meia-Idade
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