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1.
The aim of this study was to define guidelines for intravenous contrast administration in cranial CT, as currently there are no recent guidelines based on a large series of patients. In 1900 consecutive patients (1480 adults and 420 children) pre- and post-contrast scan was analysed in order to assess the contribution of contrast enhancement to the diagnosis. The findings were grouped according to whether abnormalities were seen on the pre- and/or post-contrast scan, or whether no abnormalities were seen at all. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of a pre-contrast scan were used to determine validity. Intravenous contrast enhancement only contributes to the diagnosis if a suspicious abnormality is seen on the unenhanced scan or in the appropriate clinical setting (33.6%). In the remaining patients (65.6%) there is no diagnostic contribution, except for a small number of abnormalities (0.8%). These are often anatomical variants and have no therapeutic impact. The number of contrast-enhanced cranial CT examinations can significantly be reduced by using four general guidelines for contrast administration resulting in considerable cost savings without affecting the quality of service to the patient. These guidelines are defined by the clinical findings/presentation or by the findings on the unenhanced scan. The number of contrast-related complications will be reduced, which may have medicolegal implications. These guidelines can be applied in any radiology department.  相似文献   

2.
This research investigated the relationship between the magnitude or scope of a stimulus and its subjective value by contrasting 2 psychological processes that may be used to construct preferences: valuation by feeling and valuation by calculation. The results show that when people rely on feeling, they are sensitive to the presence or absence of a stimulus (i.e., the difference between 0 and some scope) but are largely insensitive to further variations of scope. In contrast, when people rely on calculation, they reveal relatively more constant sensitivity to scope. Thus, value is nearly a step function of scope when feeling predominates and is closer to a linear function when calculation predominates. These findings may allow for a novel interpretation of why most real-world value functions are concave and how the processes responsible for nonlinearity of value may also contribute to nonlinear probability weighting. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

3.
INTRODUCTION: Almost all patients with invasive cervical carcinoma can be treated with either primary irradiation therapy or primary surgery. Some patients are appropriately treated with the combination of irradiation and surgery. Chemotherapy is not effective as primary treatment of invasive cervical cancer but may be used as additional therapy and when the disease is recurrent or persistent. There are some important advantages of primary extensive surgery over irradiation. The findings at operation and that from the careful pathologic examination of surgical specimens can be very helpful in selection of patients for supplementary postoperation irradiation therapy or chemotherapy, or both [1-6]. AIM OF THE STUDY: The aim of the study was to compare pretreatment clinical evaluations with surgical and postsurgical pathohistological findings. METHODS: Extensive hysterectomy and bilateral pelvic lymphadenectomy were used in the treatment of 251 patients with early invasive cervical cancer. The patients were treated at the Department of Obstetrics and Gynaecology of the Clinical Centre of Serbia in Belgrade, between 1993 and 1995. Cervical cancer was detected by clinical examination, colposcopic and cytologic (Pap smear) findings, colposcopically directed biopsy or conisation and pathological findings, sonography, chest radiography, blood and urine analyses. In some cases we had to make other examinations (cystography, cystoscopy, intravenous pyelography, sygmoidoscopy, rectoscopy, CT scanning and magnetic resonance). The surgical treatment of invasive carcinoma of the cervix was limited to those patients in whom the disease was confined to the cervix or vaginal fornix (stage Ia, stage Ib or stage IIa), and who were in high surgical risk. RESULTS: Over a three year period (1993-1995) there were 251 patients with invasive cervical cancer, treated by primary surgery (radical hysterectomy and bilateral pelvic lymphadenectomy sec. Werthein-Meigs), average age 42 years. Most of the patients demonstrated invasive cervical cancer, clinically classified in Ib st. (81.67%). Some characteristics of pathologic findings, such as parametric width, number of removed lymph nodes, percentage of lymph nodes metastases and correlation with clinical stage of invasive cervical cancer, histologic grade of cervical cancer with lymph node metastasis, pathologic findings after surgical treatment, correlation between clinical and surgical staging, were already presented in tables. DISCUSSION: In the last decades the incidence of invasive cervical cancer and death rate have been decreased. Progress in reducing mortality is primarily attributed to the introduction of cervical cancer screening as part of regular gynaecologic examinations. Regular testing with Papanicolaou (Pap) smear and colposcopy have an important role in this problem [1]. Extensive hysterectomy and bilateral pelvic lymphadenectomy were used in the treatment of 251 patients with early invasive cervical cancer. We found that the clinical diagnosis of disease extent was correct in 67.7% of patients who underwent extensive surgery for early invasive cervical cancer. Sensitivity of clinical findings was 75.8% and positive predictive value was 86.2%. Lymph node metastasis was detected in 17% patients. Brodman at al. [14] found that clinical examinations, including CT scanning and magnetic resonance, were correct in only 62.5% of cases. It is very difficult to detect parametric involvement and lymph node metastasis by clinical examinations. Irradiation therapy was used in the postoperative period as additional treatment of extensive hysterectomy and bilateral pelvic lymphadenectomy in 89.7% of patients. CONCLUSION: The findings at operation and that from the careful pathologic examination of surgical specimens are absolutely irreplaceable and important in grading invasive cervical cancer and selection of patients for supplementary postoperate irradiation therapy.  相似文献   

4.
OBJECTIVE: We evaluated the accuracy of unenhanced helical CT with enteric contrast material in the diagnosis of appendicitis in children and adults treated at a community hospital. SUBJECTS AND METHODS: Over an 8-month period, 100 consecutive patients with right lower quadrant pain and suspected appendicitis were prospectively evaluated. Thin-collimation helical CT scanning was performed after administration of enteric contrast material. CT interpretations were correlated with surgical pathology (45 patients) and clinical follow-up (55 patients). RESULTS: The findings of 33 CT scans were interpreted as positive for appendicitis (29 true-positives and four false-positives), and the findings of 67 were interpreted as negative for appendicitis (66 true-negatives and one false-negative). Sensitivity was 97%, specificity was 94%, accuracy was 95%, positive predictive value was 88%, and negative predictive value was 99%. In the 67 CT scans with negative findings for appendicitis, an alternative diagnosis was made for 36 patients (54%). CONCLUSION: Unenhanced helical CT with enteric contrast material for the evaluation of appendicitis can be implemented in a community hospital. In our study, such imaging achieved excellent accuracy.  相似文献   

5.
Contrast sensitivity has been shown to be affected in Alzheimer's disease (Ad). We investigated low contrast acuity and contrast sensitivity using clinical test charts in this patient population. Additionally, we tested patients with vascular dementia (vd) and mixed dementia (md), (Alzheimer' with vascular dementia). Contrast sensitivity was assessed using the Vistech VCTS 6500 test chart. Low contrast acuity was measured using the Regan charts at four contrast levels (96%, 50%, 25% and 11%). The patient population consisted of 19 Ad patients, 9 vd patients and 10 md patients. Reduction in acuity was found with contrast level in all cases. Regression lines were fit to the data and statistical analysis was performed. We did not find a statistically significant difference between the Ad and vd or md groups. We did, however, find a difference between the vd and md groups. We did find reduction in contrast sensitivity at all spatial frequencies when compared to the elderly normal. Correspondingly, we found a significant difference in acuity when compared with normal data at the four contrast levels tested. Acuity is reduced with contrast in all patient groups. Our contrast sensitivity results are similar to those reported in the literature. This study points out the importance of using simple clinical test charts and further underscores the idea that there is a primary visual deficit in Ad.  相似文献   

6.
A recent survey by Consumer Reports (1994) found that people who receive psychotherapy were generally pleased with their experience and that their satisfaction was unrelated to the type of treatment or the addition of medications. M. E. P. Seligman (1995) argued that these findings demonstrate the value of psychotherapy and suggested that such survey methodologies may be superior to randomized clinical trials in this regard because they study what occurs in actual clinical practice. Although such approaches provide important information, they are no substitute for controlled clinical trials when it comes to drawing causal inferences. However, the study does highlight the importance of defining outcome in the broadest possible fashion and of addressing the external validity of the findings obtained. Attention to such considerations has implications for the relative value of drugs and psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

7.
Despite improvements in operative and anesthesiological techniques, respiratory problems in surgical patients have been minimized but not eliminated. In addition to risks which are typical for the individual patient, the perioperative respiratory morbidity is affected by anesthesiological manipulations as well as the operation and the nature of the operation (elective versus emergency). In this paper, after describing anesthesia-associated disturbances of the respiratory situation together with worsening due to the disease in patients with COLD, techniques and methods for therapy, prophylaxis, and prognostic assessment are delineated. Two examples are given for patients with respiratory problems (abdomino-thoracic esophageal resection as a example of local trauma in patients with numerous preoperative risk factors and acute necrotizing pancreatitis to describe the sequelae of a toxic process). The essence of our discussion is that, prognostically, preoperative diagnosis is of reduced value. Only a synopsis of clinical findings together with spirometry and blood gas analysis appears to be relevant. Early mobilization in conjunction with excellent postoperative pain therapy is of utmost importance, which is equivalent to the almost routine placement of a patient controllable epidural analgesia technique. These concepts have shown in the two patient groups described that respiratory morbidity may be reduced significantly. Cooperation between surgeons and anesthesiologists, which is characterized by complete and mutually high competence on both sides, is essential for successfully managing patients at increased respiratory risk.  相似文献   

8.
Discography 2000     
Discography is an invasive and controversial procedure that can be used as a complementary test to MR imaging or a CT myelogram prior to surgery. The examination may be performed in the prone or decubitus position. Pain provocation is the most important part of the examination. CT discography provides valuable information regarding pattern, number, extent, and degree of annular tears. Correlation of discography with cross-sectional imaging studies is reviewed and the surgical outcome is discussed.  相似文献   

9.
The purpose of this study was to evaluate the prognostic value of neonatal E.E.G. tracings in children born at term. The clinical course of 45 children was followed and related to E.E.G. abnormalities reported during the first 5 days of life. Essentially the findings confirmed those previously reported by others. However some differences were noted: paroxysmal tracings were not associated with a poor clinical state, and moderately abnormal tracings (the prognostic significance of which has never been defined) led on sometimes to a severe encephalopathy. We wish to stress certain aspects of our findings: -recordings in the first 24 hours of life may be misleading. -recordings, to be of value, must be taken before any treatment which could induce paroxystic E.E.G. patterns. -E.E.Gs should be repeated during the post-natal period when the findings are non-specific. -the prognostic significance of tracings reported as "generalised or localised overactivity" should be evaluated.  相似文献   

10.
The tuning of the transient-stereopsis system to luminance contrast and spatial-frequency (SF) was investigated with narrow-band gabor targets with a constant sigma of 1 degree. They were presented for brief (140 ms) durations and subtended a large (6 degrees) disparity. When dichoptic gabor stimuli were matched in SF (0-5 cpd), transient stereo performance was either uniform across SF or greater at frequencies below 1 cpd. When dichoptic stimuli had unmatched SF (0.5 + 0-5 cpd) and matched contrast (100%), stereo performance was impaired below that of the matched SF condition. Stereo performance with matched SF at 0.5 cpd was impaired when contrast of one eye's image was reduced, demonstrating a contrast-paradox effect (i.e. contrast tuning) for transient stereopsis. Performance with three dichoptic unmatched SF conditions (0.5 and 1.0 cpd; 0.5 and 5.0 cpd; 1.5 and 3.5 cpd) was improved when the contrasts of the low SF gabor was reduced while holding the contrast of the high SF gabor constant at 100%. However stereo performance was not improved by reducing the contrast of a high SF gabor (3.5 cpd) while holding the contrast of the lower SF gabor (1.5 cpd) constant at 100%. We interpret these findings as indicating that transient-stereopsis performance is mediated by a single spatial-channel that has low-pass spatial-frequency sensitivity and which compares the ocular based signals prior to binocular combination so that signals that are not balanced in terms of their strength lead to a weaker binocular signal, as per the model proposed by Kontsevich and Tyler (Vis Res 1994; 3417:2317-2329) for sustained stereopsis.  相似文献   

11.
Myocardial contrast echocardiography is a technique used in experimental and clinical settings in order to visualize the pattern of intramyocardial perfusion. In the acute phase of myocardial infarction, regional absence of flow during myocardial contrast echocardiography delineates the area at risk of necrosis, while the definitive non-perfused area expresses infarct size. Reopening the infarct-related artery, which may be achieved spontaneously by thrombolysis or percutaneous transluminal coronary angioplasty, is not a reliable indicator of intramyocardial reperfusion. If myocardial ischaemia due to coronary occlusion has been sufficiently prolonged and severe, not only myocyte viability, but also microvascular integrity is lost. Myocardial contrast echocardiography, using intracoronary injection of sonicated contrast medium, gives information about microvascular integrity and the effective presence of intramyocardial reflow. Anatomical integrity of microvasculature does not necessarily imply preserved function, and thus the microvessel vasodilating reserve may also be impaired. Myocardial contrast echocardiography has the potential to assess alterations in microvascular function, showing, in the myocardial area with reduced coronary reserve, a relatively reduced increase in echocontrast signal intensity when an intravenous vasodilator agent is administered.  相似文献   

12.
To determine the mechanisms underlying diabetic nephropathy (DN) onset, a clinical and morphological study was initiated of 14 diabetics with insulin-dependent disease free of clinical renal manifestations. The patients were examined for intraglomerular hypertension, blood lipid spectrum and renal tissue morphology. In high intraglomerular hypertension, i. e. in renal functional reserve depletion, there is dyslipidemia with a characteristic significant rise in the levels of very low density lipoprotein cholesterol and low density lipoprotein cholesterol, in the value of atherogenic index. Morphologically, renal tissue of the hypertensive and dyslipidemic patients experienced hyperperfusion and massive lipid infiltration in glomerular cells. In contrast, renal tissue underwent only minimal nonspecific changes when intraglomerular hemodynamics and lipidemia were normal. The findings suggest that associated effects of intraglomerular hypertension and dyslipidemia may promote DN onset.  相似文献   

13.
Airway responsiveness assessed using histamine and methacholine is safe, reproducible and relatively easily undertaken in adults and children. Results are similar for methacholine and histamine although methacholine is better tolerated. Responsiveness is increased in children and the elderly, and in women compared to men, possibly due to body size effects. Baseline lung function confounds the interpretation of airway responsiveness and may explain the effect of smoking in most studies. Results are most usefully expressed as the provocative dose producing a 20% fall in FEV1 (PD20FEV1) or the dose-response slope (DRS). When technical factors are controlled the reproducibility of the test is from one to two doubling doses. Measurements of airway responsiveness have been widely used in clinical and research practice. However, assessing their value in diagnosing asthma is limited by the lack of a gold standard for the definition of asthma. Using a cut-off value of 8 mg/mL or 8 mumol for PD20, the tests will discriminate asthmatic from non-asthmatic subjects (based on questionnaire definitions of asthma) with a sensitivity of around 60% and a specificity of around 90%. These properties of the test result in positive and negative predictive values of 86% and 69% when the prevalence of asthma is high (50%-as in the clinical setting) and 40% and 95% when the prevalence of asthma is low (10%, as in general population studies). In the usual clinical setting, assessing the significance of atypical or non-specific symptoms, the tests are of intermediate value in predicting the presence of asthma and less useful in excluding asthma. The additional benefit of testing airway responsiveness to measuring peak flows or to a trial of therapy has yet to be fully assessed. Testing of airway responsiveness may be of value in assessing occupational asthma, asthma severity and the effects of potential sensitizers or treatments. In research, tests of airway responsiveness are more useful for excluding cases of asthma. In population studies, they serve as an objective marker of abnormal airway function which may be genetically determined and, like allergy, are strongly associated with asthma. The predictive value of airway hyperresponsiveness for the development of airway disease is yet to be clearly established. In epidemiology the benefits of measuring airway responses must be weighed against the added inconvenience and cost that is incurred.  相似文献   

14.
OBJECTIVES: This study assessed the agreement of left ventricular ejection fraction determinations from two-dimensional echocardiography, radionuclide angiography and contrast cineangiography. BACKGROUND: Previously published reports suggest that two-dimensional echocardiography, radionuclide angiography and contrast cineangiography are equally acceptable methods of assessing left ventricular ejection fraction on the basis of high coefficients of correlation. However, correlation of methods does not necessarily imply agreement. METHODS: In a prospective analysis, 25 consecutive subjects all had two-dimensional echocardiography and radionuclide angiography performed within 10 days of each other in the cardiology department of metropolitan community hospital. A retrospective computer search (Medline) revealed seven studies, using the coefficient of correlation (r), comparing two-dimensional echocardiographic left ventricular ejection fraction (n = 268) with radionuclide angiographic (n = 174) or contrast cineangiographic (n = 119) left ventricular ejection fractions. RESULTS: The eight individual studies (n = 293) comparing two-dimensional echocardiography with either radionuclide angiography or contrast cineangiography exhibited coefficients of correlation ranging from 0.78 to 0.93. Agreement analysis using the method of Bland and Altman was performed by averaging the results obtained from the two techniques and determining how disparate any single ejection fraction was (with 95% confidence limits) from the mean value. Agreement ranged from 23% to 42% around the mean ejection fraction. The average lack of agreement between the two methods for all studies involved was 17%, with an average r value of 0.86. CONCLUSIONS: Left ventricular ejection fraction determinations by means of two-dimensional echocardiography, radionuclide angiography and contrast cineangiography exhibit high correlation and only moderate agreement. High correlation does not always imply high agreement. These results suggest that, when validated by agreement analysis, multiple studies may not be necessary in appropriate clinical situations, potentially reducing costs.  相似文献   

15.
Our experience is reported with 20 consecutive patients undergoing the Bentall operation during the past 10 years for ascending aortic aneurysms with aortic regurgitation due to idiopathic medical necrosis with a resultant annulo-aortic ectasia. Concomitant aortic dissection was present in 45% of the patients. In the earlier period from 1972 to 1976, the operative and hospital mortality rates were 40%, and it was reduced to 0% (p less than 0.08) in the later period from 1977 to 1981. Operative survivors showed the mean clinical improvement from the NYHA class 3.0 to 1.3. The LVEDP and the left ventricular dimension were significantly reduced toward normal (p less than 0.05 and p less than 0.001). The actuarial survival rate at 6 years after operation was 71% in this series. The Bentall operation can now be performed with a low risk, and can improve the clinical and hemodynamic states significantly. However, in patients with chronic type I aortic dissection, a false lumen remained patent after surgery regardless of the types of graft-distal aorta anastomosis. The fate of the remaining dissection is undetermined, but some may require further surgery.  相似文献   

16.
OBJECTIVE: To assess the efficacy of ultrasound (US) as part of an algorithm to establish the indication for laparotomy in patients with suspected acute appendicitis. DESIGN: Prospective investigation. SETTING: University department of surgery, Germany. SUBJECTS: 669 unselected patients admitted with suspected acute appendicitis. INTERVENTIONS: Clinicopathological and procedural diagnoses of the algorithm were evaluated by correlating clinical and US findings with the results of laparotomy in 171 patients of whom 143 had acute appendicitis (prevalence 21%), and clinical as well as follow up data in the remainder. MAIN OUTCOME MEASURES: The major clinicopathological variables were accuracy and positive predictive value; the rate of negative laparotomies and that of bad diagnostic errors served as the main procedural variables. RESULTS: The overall sensitivity, specificity, and accuracy of the clinical diagnosis were 0.503, 0.950, and 0.855, respectively (positive predictive value: PPV 0.734, negative predictive value: NPV 0.875), those of ultrasound: 0.797, 0.967, and 0.931 (PPV 0.870, NPV 0.946); and 0.853, 0.927, and 0.940 at the end of the algorithm (PPV 0.762, NPV 0.958). However, the algorithm would have resulted in a significant increase in the rate of unnecessary laparotomies (from 13% to 16%). A revised clinical algorithm gave an overall diagnostic accuracy of 0.940 (p < 0.001) together with a low rate of negative laparotomies (11%, p < 0.01) and a significantly reduced number of diagnostic errors (from 71 to 21, p < 0.001). CONCLUSION: Ultrasonography enabled us to diagnose acute appendicitis in more patients more often and more quickly than clinical evaluation alone, suggesting that US may produce a better outcome. The revised clinical algorithm may be helpful in the study of US in patients with suspected acute appendicitis in prospective randomised controlled clinical trials.  相似文献   

17.
It has been suggested that inhibitors of nitric oxide synthesis are of value in the treatment of hypotension during sepsis. In this pilot study, we examined the effects of inhibition of nitric oxide synthesis by continuous infusion of N(omega)-nitro-L-arginine methyl ester (L-NAME) at 1.5 mg/kg/h in a patient with severe septic shock. L-NAME produced a rise in mean arterial blood pressure and systemic vascular resistance; catecholamine infusion could be reduced. Parallel to these findings, there was a 50% reduction in cardiac output and a 5-fold rise in pulmonary vascular resistance, which resulted in severe pulmonary hypertension after 3 h of L-NAME infusion, for which the infusion had to be stopped. Following the termination of L-NAME infusion, pulmonary artery pressure and blood pressure returned to baseline values, although pulmonary and systemic vascular resistance remained elevated for several hours. We conclude that nitric oxide appears to play a role in the cardiovascular derangements during human sepsis. Inhibition of nitric oxide synthesis with L-NAME can increase blood pressure and systemic vascular resistance. However, reduced cardiac output and pulmonary hypertension are possible side effects of continuous NO synthase inhibition. These side effects necessitate careful monitoring and may hinder the clinical application of NO synthase inhibitors.  相似文献   

18.
Development of vascularization of the anterior part of the medial rectus muscle after Cüppers' thread operation was studied by injected barium sulphate into the ophthalmic artery of 8 corpses. Properly distributed and normally tightened myoscleral sutures, as with surgical operations for strabismus, do not hinder circulation of the contrast medium, whereas markedly tightened sutures interrupt its circulation. These experimental results as well as clinical and pathological findings following 18 repeat surgical operations, clearly show that Cüppers' thread operation is not hazardous when a very strict operative technique is respected.  相似文献   

19.
The performance of hysterosalpingo contrast sonography (Hy Co Sy) as a first-line, outpatient investigation of tubal patency was examined in 500 consecutive, infertile women, at one centre. Hy Co Sy was completed in 463 (92.6%) cases, using a galactose microbubble contrast agent (Echovist-200) and transvaginal sonography. Initial plain scanning identified adnexal pathology in 198 women (39.6%). Examination with Echovist was attempted for 905 tubes and only 67 (7.4%) were not assessable; after the first 100 women this decreased to 35 tubes (4.8%). A sonographic appearance compatible with blocked tubes was found on 118 (14.1%) occasions but it was also possible to identify variations in the appearance/filling/spilling patterns of individual tubes which increased the number assessed as abnormal to 193 (23.0%). Comparison with laparoscopy and dye chromopertubation findings from the past three years was possible for 185 (37%) women, representing 282 tubes, which gave Hy Co Sy an overall concordance rate of 85.8%, sensitivity of 90.4%, specificity of 70.3%, positive predictive value of 91.2% and negative predictive value of 68.2%. Some 51.0% of women described only mild discomfort and there were no significant postprocedure complications. Hy Co Sy appears to be an acceptable first-line screen and may select out women in whom more invasive investigations are likely to reveal pathology.  相似文献   

20.
BACKGROUND: Ultrasonography (US) by acknowledged experts enhances the diagnostic performance and reduces the rate of negative laparotomies in patients with suspected acute appendicitis (AA). METHODS: The diagnostic accuracy and clinical impact of routine US performed by surgical residents was prospectively studied in 504 unselected patients admitted for AA. Clinical and US findings were correlated with laparotomy findings and pathological outcome in 135 patients (113 cases with proven AA, prevalence 22.4%) and clinical as well as follow-up data were compared in the remainder. RESULTS: The overall accuracy, sensitivity, and specificity of the clinical diagnosis of AA were 84.9%, 51.3%, and 94.6% and those of US were 93. 6%, 83.1%, and 96.6%. Joint evaluation of the results from clinical evaluation and US further improved diagnostic performance (accuracy 93.4%, sensitivity 84.1%, specificity 96.2) and significantly reduced the rate of diagnostic errors to 3.4% (p < 0.001) and unnecessary laparotomies to 9.6% (p < 0.01) in patients with suspected AA. CONCLUSIONS: Ultrasonographic evaluation of the patient with suspected AA is considered to be of value in surgical practice.  相似文献   

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