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N T Nielsen

Publications and source records attributed to N T Nielsen.

8 recordsLinked to original sources
PubMed1999

Chest roentgenogram in the evaluation of heart defects in asymptomatic infants and children with a cardiac murmur: reproducibility and accuracy.

OBJECTIVES: To evaluate the reproducibility and the accuracy of pediatric radiologists' assessments of chest radiographs with respect to the presence or absence of heart defects in children with an asymptomatic heart murmur. DESIGN: Ninety-eight children, ages 1 month to 15 years (median, 30.1 months), referred for evaluation of a heart murmur were consecutively included. They all had a standard chest radiograph and a color Doppler echocardiograph (CDE) performed. Six specialists in pediatric radiology evaluated the chest radiographs independently on two occasions 6 months apart. The radiologists were asked to classify each set of films into one of two categories: heart disease or no heart disease. The outcome of the CDE was considered the definite diagnosis. kappa statistics were used to analyze the reproducibility of the radiologic assessments. Sensitivity, specificity, and the predictive value of a positive and a negative test were used for evaluation of the accuracy of the radiologic assessments. RESULTS: Mean intra- and interobserver kappa values were all <0.6, and the majority were <0.4. Mean sensitivity was 0.3 (range: 0.17-0.52), mean predictive value of a positive test was 0.4, implying that 60% of the positive assessments were falsely positive. Mean specificity was 0.86 (range: 0.75-0.93) and the mean predictive value of a negative test was 0.80 implying that 20% of the negative assessments were falsely negative. CONCLUSION: We found a low reproducibility, as well as a low accuracy, of the radiologic assessments of the chest radiographs of children with an asymptomatic heart murmur with respect to the presence or absence of heart disease. A false-positive radiologic assessment of the chest radiograph with respect to heart defects causes unnecessary anxiety and further examinations, whereas a false-negative assessment might result in omission of relevant investigations and proper identification of the heart defect. We cannot recommend the use of chest radiographs in the initial evaluation of the asymptomatic child with a heart murmur. If a heart defect cannot be excluded by clinical examination a CDE must be performed.

Adolescent↗
PubMed1993

[CT in the prognostic evaluation of apoplexy].

The purpose of our prospective study was to determine whether cranial computed tomography in connection with neurological assessment was useful in prognostic evaluation of survival after acute stroke. Two-hundred and forty-five consecutive stroke patients were included. Each underwent detailed neurological assessment and cranial computed tomography without intravenous contrast injection. The lesions were divided according to neuroanatomic regions. In the statistical analyses we used a multiple logistic regression model. Computed tomography showed that 76% of the patients had infarcts. 11% had haemorrhages, and 13% had no acute lesion. Forty-three patients had more than one acute lesion, and 57 had one or more old infarcts. The temporal, parietal and frontal regions and the basal ganglia were most often affected. We concluded that age, level of consciousness, and involvement of the temporal lobe on computed tomography were factors of prognostic significance regarding survival in the acute phase.

Acute Disease↗
PubMed1992

Computed tomography in prognostic stroke evaluation.

BACKGROUND AND PURPOSE: Computed tomography is now routinely used in many hospitals to investigate cerebrovascular disease. The purpose of our prospective study was to determine whether cranial computed tomography in connection with neurological assessment was useful in prognostic evaluation of survival after acute stroke. METHODS: Two-hundred forty-five consecutive stroke patients were included in the project during a 1-year period. Each had a detailed neurological assessment 24-72 hours after stroke onset and underwent cranial computed tomography without intravenous contrast injection within the first week after admission. The lesions were divided according to neuroanatomic regions. In the statistical analyses we used a multiple logistic regression model with survival/death as the binary variable. RESULTS: Computed tomography showed 76% of the patients had infarcts, 11% had hemorrhages, and 13% had no acute lesion. Forty-three patients had more than one acute lesion, and 57 had one or more old infarctions. The temporal, parietal, and frontal regions and the basal ganglia were most often affected. CONCLUSIONS: We conclude that age, level of consciousness, and involvement of the temporal lobe on computed tomography were factors of prognostic significance regarding survival in the acute phase.

Adult↗
PubMed1991

Detection of deep venous thrombosis with indium 111-labelled monoclonal antibody against tissue plasminogen activator.

The administration of a radiolabelled monoclonal antibody against tissue plasminogen activator allows detection of areas with increased fibrinolytic activity, i.e. those with an active thrombotic lesion. Eight patients with phlebographically verified deep venous thrombosis were examined. At the time of immunoscintigraphy study they were examined receiving anticoagulant therapy. Some 75-85 MBq indium 111-labelled antibody were injected, and scintigrams were obtained after 30 min and after 24 h. The precise site of the thrombus could not be visualized after 30 min due to high background activity, whereas after 24 h it was detectable in all patients. The thrombus/background ratios achieved are twice as high as those observed in a human antifibrin antibody study. These preliminary data suggest a high sensitivity of our t-PA-specific antibody for the detection of active deep venous thrombosis in man, and our antibody seems to offer theoretical advantages over both platelet and fibrin-specific antibodies.

Antibodies, Monoclonal↗
PubMed1985

Iohexol and ioxithalamate for intravenous urography. A comparative parallel study.

Omnipaque (iohexol) 350 mg I/ml has been compared with Telebrix (ioxithalamate) 380 mg I/ml in 48 patients undergoing intravenous urography. The contrast medium dose corresponded to 400 mg I/kg body weight. No cardiovascular reactions (BP and pulse rate) were observed. Subjective reactions occurred somewhat more frequently after Telebrix than after Omnipaque. Sensation of warmth was significantly less with Omnipaque (p less than or equal to 0.05). The overall radiological quality was equally good for the two contrast media.

Adult↗