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At least 667 records · Page 37Linked to original sources
PubMed1985

Accuracy of radiographic caries diagnosis at different kilovoltages and two film speeds.

Different kilovoltages (50, 60, 70, 90) and two films differing in speed (Kodak Ultra-Speed and Ektaspeed) were examined with regard to the diagnostic accuracy at detection of dental caries. Ten observers graded the occurrence of caries in radiographs of extracted premolars and their findings were compared with the actual presence or absence of caries. The ROC-technique was used to evaluate the results using the area under the curve as a measure of diagnostic accuracy. A significant difference was found between kilovoltages with better diagnostic accuracy for the lower kilovoltages. No significant difference was found between the two types of film. Our results suggest that a kilovoltage of 60 offers a proper balance between absorbed radiation dose and diagnostic accuracy. The use of Kodak Ektaspeed offers a diagnostic accuracy similar to that of Kodak Ultra-Speed.

Absorptiometry, Photon↗
PubMed1985

[Comparison of vascular width and accuracy in the subjective assessment of pulmonary circulation in the roentgen picture of children with left-right shunts].

The authors established a comparative relationship between accuracy of measurement of pulmonary flow and extent of vascular widening in 72 children with Left-Right shunt vitiae; this accuracy of pulmonary flow measurement had been subjectively estimated by 4 investigators without knowing the diagnosis and in comparison to the haemodynamic values (percentage of correct findings). The following procedure was adopted: In a control group of 143 healthy children, we first determined the vascular diameter of the right descending pulmonary artery, of the right upper lobal vein, and of the peripheral vessels in the upper and lower pulmonary fields, at an accurately defined distance from the point of the hilus, and compared with the vascular diameters of the children with left-right shunt, employing the method of discrimination analysis. Comparison of the judgement by the 4 investigators with the degree of increase of the vascular diameters showed an accuracy of 65-100% if the right descending pulmonary artery became wider by 2.6 mm, and an accuracy of 79-95% if the mean vascular width in the right upper field increased by 0.7 mm. The accuracy was 83-94% if the mean vascular width in the right lower field increased by 0.6 mm. Statistical studies also showed that the judgement of the 4 investigators was influenced by different vessels.

Adolescent↗
PubMed1979

Evaluation of colposcopic accuracy without endocervical curettage.

A study was undertaken to evaluate the accuracy of colposcopic examination when performed without the use of endocervical curettage. It included 763 cases of suspected cervical-vaginal pathology. An additional evaluation of colposcopic accuracy was made for special-case categories of 1) stromal invasion, 2) pregnancy, 3) menopause, and 4) diethylstilbestrol (DES) exposure. Colposcopic accuracy was determined by cytologic and histologic material obtained either at the initial colposcopic evaluation or during follow-up surgery. With the literature as a standard for accuracy, it was concluded that the omission of endocervical curettage from the colposcopic examination did not reduce accuracy. In addition, the diagnostic conization rate was lower than in most reported series. Finally, the rate of missed invasive lesions was not increased by the omission of endocervical curettage.

Adolescent↗
PubMedDate not supplied

Factors significant in the diagnostic accuracy of lung cytology in bronchial washing and sputum samples. I. Bronchial washings.

Some factors influencing the diagnostic accuracy for primary lung cancer in bronchial washings were studied in 276 consecutive cases seen between 1959 and 1974. Diagnostic accuracy increased during the years under study; the reasons included increasing expertise of the laboratory staff, better documentation of cytologic criteria and improved collection techniques. The overall accuracy was 74%. Detection of malignant cells was highest for squamous-cell and adenosquamous carcinomas (81%), small-cell carcinoma, adenocarcinoma and large-cell carcinoma (70%) and lowest for bronchioloalveolar-cell carcinoma (47%). Accuracy was 84% for central tumors as compared to 30% for peripheral lesions. Tumors of less than 2 cm in diameter yielded very poor results (15%) while those greater than 2 cm yielded 82% accuracy. The specificity of diagnosis of cell type in those specimens with malignant cells was over 93% for squamous-cell carcinoma, small-cell carcinoma and adenocarcinoma, 77% for large-cell carcinoma and below 50% for adenosquamous carcinoma, bronchioloalveolar carcinoma and the uncommon tumors. Two bronchial washings per case gave an appreciably better result (92%) than one per case (68%). The percentage of unsatisfactory specimens from those with cancer was 13.5 and from a control group was 29.9. Reasons for unsatisfactory specimens included limited cellular material, excessive blood and/or leukocytes and drying artifacts.

Adenocarcinoma↗
PubMedDate not supplied

Ultrasound-guided percutaneous fine needle aspiration biopsy of abdominal and retroperitoneal masses. Accuracy of cytology in the diagnosis of malignancy, cytologic tumor typing and use of antibodies to intermediate filaments in selected cases.

The reliability of ultrasound-guided fine needle aspiration biopsy (FNAB) in the detection of intraperitoneal and retroperitoneal malignancies was evaluated in 308 consecutive cases seen between 1979 and 1983. The prevalence of malignant neoplasms was 68.5%. The overall accuracy of FNAB diagnosis was 88.9%, with a sensitivity of 84.4% and a specificity of 98%. The predictive value of positive and negative results were 98.9% and 74.6%, respectively. Additionally, the cytologic results were statistically evaluated with respect to the different sites of the biopsied lesions (including pancreas, liver, kidneys and miscellaneous sites). The overall accuracy was highest for malignant lesions in the liver (96.4%) and in miscellaneous sites (89.5%). Reasons for false-negative results included incorrect areas sampled, limited material due to fibrosis or necrosis and cytologic misinterpretations. The accuracy of cytologic tumor typing with respect to histogenetic origin was 96.8%. Cytologic subclassification was performed with lower accuracy (82.5%), and exact determination of the site of the primary tumor from cytologic criteria alone was possible for 35.7% of carcinomas. In selected cases, routine cytologic examination was supplemented by intermediate filament typing using well-characterized antibodies against cytokeratin, vimentin, desmin and neurofilaments. Examples are shown in which use of this method clearly increased the accuracy of the diagnosis. Only two serious complications (bleeding) of fine-needle aspiration biopsy were encountered in this series.

Antibodies↗
PubMed1983

Precision and accuracy of intraoperative temperature monitoring.

Using tympanic membrane (TM) temperature as a standard for core temperature, we quantitated the accuracy and precision of seven other temperature monitoring sites during anesthesia, namely, the nasopharynx, esophagus, rectum, bladder, axilla, forehead, and great toe. Accuracy was quantitated as the difference between TM temperature and the temperature at each of the other sites; precision was quantitated as the correlation between TM temperature and the temperature at each of the other sites. Results indicate that the accuracy of measurements made using the great toe, forehead, and axilla is less than the accuracy of measurements made using the nasopharynx, esophagus, bladder, and rectum. Precision of measurements made using the nasopharynx, esophagus, and bladder is greater than the precision at the axilla, forehead, and rectum, and much higher than the precision at the great toe. Measurements of body temperature using the nasopharynx, esophagus, and bladder are recommended for intraoperative use as providing the best combination of accuracy and precision.

Adult↗
PubMed1993

Therapy evaluation and diagnostic accuracy in neuroendocrine tumours: assessment of radiological methods.

The diagnostic accuracy of ultrasonically guided biopsy-gun biopsies was assessed in a group of 47 patients with suspected pancreatic carcinoma. A correct diagnosis with the aid of biopsy was obtained in 44 of the 47 patients (94%). In 3 patients with a carcinoma of the pancreas the correct diagnosis was not obtained with the first biopsy. In 2 of these 3 patients, a simultaneous biopsy of a liver metastasis revealed the presence of malignant tumour growth. No major complications occurred. Biopsy-gun biopsy of the pancreas is considered a useful, reliable and non-traumatic method for the diagnosis of pancreatic malignancy. Twenty-five patients with known neuroendocrine tumour disease were biopsied with 1.2 mm and 0.9 mm biopsy-gun needles to evaluate the respective diagnostic accuracy of the 2 needle sizes. The influence of treatment-related fibrosis on the histopathological diagnosis was also evaluated. The overall diagnostic accuracy with the 0.9 mm needle was 69% as compared to 92% with the 1.2 mm needle. This difference, however, seems more related to needle guiding difficulties with the 0.9 mm needle than to insufficient tissue yield. The increased amount of fibrous tissue due to interferon treatment did not seem to negatively influence the diagnostic accuracy. In order to assess the diagnostic accuracy rate for radiologists with different experience of biopsy procedures 175 cases of renal biopsy-gun biopsies were evaluated. No statistical significant difference was found between the different operators. Provided with detailed instruction even operators with limited experience produced biopsy results equal to those of operators with extensive practice in ultrasound-guided biopsies. The automated sampling performance of the biopsy-gun, with a consistent high diagnostic sampling rate (96%), was believed to be responsible for these results. The role of duplex Doppler ultrasound in monitoring interferon treatment-related changes in carcinoid metastases was evaluated. The patients were divided into 4 groups: untreated (n = 10), progressive disease (n = 17), stable disease (n = 20) and objective response (n = 18). No significant differences in Doppler values were found between the groups, and at present duplex Doppler ultrasound does not seem to play a role in the evaluation of tumour therapy in carcinoid patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

The accuracy of automated blood pressure measuring devices in patients with controlled atrial fibrillation.

OBJECTIVE: To determine whether automated blood pressure measuring devices can measure blood pressure accurately in patients with atrial fibrillation. DESIGN: Comparison of the accuracy of two electronic sphygmomanometers [Takeda UA-751 (Takeda) and Copal UA-251 (Copal)] and two ambulatory blood pressure monitors [Accutracker 1 (Accutracker) and SpaceLabs 90207 (SpaceLabs)] with that of a trained observer using a Hawksley random-zero sphygmomanometer (Hawksley), using the sequential same-arm technique. SETTING: University teaching hospital: medical wards and outpatient department. SUBJECTS: Twenty-eight patients, mean +/- SD age 72 +/- 9 years, blood pressure range 90-158/40-96 mmHg, in atrial fibrillation with a controlled ventricular rate. MAIN OUTCOME MEASURES: The proportion of machine readings > 5 mmHg different from the Hawksley reading was compared with that obtained by three sequential Hawksley measurements. The variability of each measuring method was assessed by determining the SDD for the paired readings from each device. RESULTS: Five per cent of Takeda, 5% of Copal, 14% of Accutracker and 21% of SpaceLabs readings could not be obtained. Sequential testing with the Hawksley resulted in an accuracy at the 5-mmHg level of (systolic/diastolic) 79/79%, compared with 64/54% (P < 0.05 for diastolic) for the Takeda, 68/75% (NS) for the Copal, 50/36% (P < 0.01 for both) for the Accutracker and 50/29% (P < 0.01 for systolic, P < 0.001 for diastolic) for the SpaceLabs. Intrapatient variability, as assessed by SDD, was 8.3/8.6 mmHg for the Hawksley, similar to that for the Copal (7.7/7.3 mmHg) but higher for the Takeda (11.2/19.7 mmHg), the Accutracker (22.4/26.3 mmHg) and the SpaceLabs (7.5/14.8 mmHg). CONCLUSIONS: Accurate measurement of blood pressure with an electronic device is possible in patients who have atrial fibrillation; the Copal UA-251 provides a satisfactory level of accuracy. However, the marked difference between devices and the limited accuracy of the other machines tested here demonstrates the need to ensure that such devices are of proven accuracy in this patient group.

Aged↗
PubMed1993

Accuracy of fine needle aspiration cytology of abdominal masses without radiological guidance.

This study was undertaken to evaluate the accuracy of FNAC of abdominal masses without the help of radiological guidance and to determine factors which affect the outcome of the procedure. Five hundred consecutive patients were studied. FNAC was reported by a single cytopathologist without knowledge of subsequent histology. In calculating indices of accuracy of FNAC only those patients in whom both FNAC and histology reports were available (N = 383) were considered. The overall incidence of unsatisfactory specimens was 5.6%. Consistency of the mass did not affect accuracy of FNAC. However, age (below 12 years) plane of the swelling, mobility of mass and size of the swelling, all significantly affected the adequacy of cytological yield. The overall true positive rate was 100.0% and there were no false positives. The true negative rate was 40.2% and false negative rate was 70.9%. The high false negative rates in hepatic and pancreatic lesions can be reduced by imaging techniques. Luminal organs had poor accuracy rates. The overall accuracy rate was 73.5%, comparable to that reported in literature. A positive diagnosis of malignancy had a 100% predictive value. Overall, it appears that nonguided FNAC is as accurate as guided FNAC except for very small lesions or discrete lesions such as hepatic secondaries where guidance may be useful.

Abdominal Neoplasms↗
PubMed1994

Accuracy of technicians and pharmacists in identifying dispensing errors.

The accuracies with which pharmacists and technicians checked medications in a unit dose distribution system were compared. The study was conducted at three large hospitals in Washington State. From August through October 1991, technicians filled unit dose medication drawers and pharmacists verified the accuracy of each fill (pharmacist verification period). From November 1991 through January 1992, technicians who had undergone special training verified the accuracy with which medication drawers were filled by other technicians (technician verification period). For each study period, two error rates were estimated: the frequency with which the pharmacists or technicians identified dispensing errors and the frequency of verification errors identified by the investigators in a final independent check. A total of 143,952 unit doses were dispensed during the pharmacist verification period, of which 49,718 were randomly analyzed for accuracy. A total of 151,721 doses were dispensed during the technician intervention period, of which 55,470 were assessed. The mean +/- S.E. daily rates of dispensing-error identification by pharmacists (0.0125 +/- 0.0069%) and technicians (0.0119 +/- 0.0001) did not differ significantly. While pharmacists overlooked more errors (107) than technicians (50), the percentage of such missed errors classified as potentially serious did not differ significantly between the groups (25.2% versus 32.0%, respectively). Pharmacy technicians who underwent special training were able to verify medications in a unit dose distribution system without compromising the accuracy of dispensing.

Education, Pharmacy↗
PubMed1993

Comparison of the diagnostic accuracy of positive-contrast arthrography and arthrotomy in evaluation of osteochondrosis lesions in the scapulohumeral joint in dogs.

During a 6-year-period (1985-1991), 120 positive-contrast arthrograms were made in 70 dogs to evaluate osteochondrosis lesions in the scapulohumeral joint. In 76 shoulders, the arthrographic findings were compared with surgical or histopathologic findings to evaluate the accuracy of the arthrographic technique. Positive-contrast arthrography was found to be accurate in evaluation of the status of the articular cartilage. In revealing discontinuity of the articular cartilage, the results of arthrography were false-negative in 4 shoulders (58/66; accuracy, 88%). In detecting thick cartilage covering a subchondral defect, the results of positive-contrast arthrography were false-positive in 4 joints (6/11; accuracy, 55%). In detecting fragmentation of the cartilage, arthrography provided false-negative results in 4 joints (7/11; accuracy, 64%). This technique enabled detection of joint mice, especially within the bicipital tendon sheath (no false-positive results). Arthrography failed to reveal joint mice within the caudal pouch in 2 joints (15/17; accuracy, 88%). Joint effusion also could be evaluated and was correlated with synovitis, degenerative joint disease, and loose or detached cartilage flaps. Postarthrography complications were not observed with this technique.

Animals↗
PubMed1993

[Sonography of pregnancy in sheep. II. Accuracy of transrectal and transcutaneous pregnancy diagnosis].

Pregnancy was diagnosed by transcutaneous ultrasonography in 327 ewes of 2 flocks. In addition transrectal sonography was performed in 93 of these ewes. Two hundred and thirty six ewes were pregnant and 88 animals were non-pregnant. Criteria to assess the accuracy of transrectal and transcutaneous sonography were overall accuracy (correct diagnoses/all diagnoses), sensitivity (correct diagnoses "pregnant"/all pregnant animals), specificity (correct diagnoses "non-pregnant"/all non-pregnant animals), predictive value of positive diagnoses (correct diagnoses "pregnant"/all diagnoses "pregnant"), predictive value of negative diagnoses (correct diagnoses "non-pregnant"/all diagnoses "non-pregnant"). Accuracy, sensitivity, specificity, predictive value of positive diagnosis and predictive value of negative diagnosis were 95%, 95%, 91%, 99% and 71% with the transcutaneous sonography resp. 94%, 95%, 93%, 97% and 86% with the transrectal sonography. Accuracy of the transrectal examination was superior (100%; 26/26) to the transcutaneous approach (89%; 39/44) in early pregnancy (Day 22 to 90). Transcutaneous sonography was more appropriate during the last part of pregnancy. The results demonstrate that both methods allow reliable pregnancy diagnosis in sheep under farm conditions. Ultrasonic pregnancy diagnosis is of economical value, if pregnancy rate of herds is below 90% and the diagnostic accuracy reaches at least 95%.

Animals↗
PubMed1993

Accuracy of references and quotations in veterinary journals.

The accuracy of references and quotations used to substantiate statements of fact in articles published in 6 frequently cited veterinary journals was examined. Three hundred references were randomly selected, and the accuracy of each citation was examined. A subset of 100 references was examined for quotational accuracy; ie, the accuracy with which authors represented the work or assertions of the author being cited. Of the 300 references selected, 295 were located, and 125 major errors were found in 88 (29.8%) of them. Sixty-seven (53.6%) major errors were found involving authors, 12 (9.6%) involved the article title, 14 (11.2%) involved the book or journal title, and 32 (25.6%) involved the volume number, date, or page numbers. Sixty-eight minor errors were detected. The accuracy of 111 quotations from 95 citations in 65 articles was examined. Nine quotations were technical and not classified, 86 (84.3%) were classified as correct, 2 (1.9%) contained minor misquotations, and 14 (13.7%) contained major misquotations. We concluded that misquotations and errors in citations occur frequently in veterinary journals, but at a rate similar to that reported for other biomedical journals.

Periodicals as Topic↗
PubMedDate not supplied

Accuracy of urinary cytology in the diagnosis of primary and recurrent bladder cancer.

Two thousand two hundred thirteen smears of urinary specimens from 263 patients with bladder disorders were reviewed and the results correlated with the clinical status at the time of urine collection and with the histologic diagnosis during follow-up. In all cases a cytologic diagnosis of malignancy was histologically confirmed at follow-up, reflecting the high predictive value of a positive result in cytology. Cytologic diagnoses were also analyzed for the interval between the cytologic and histologic diagnosis of malignancy. In cases of cytologic diagnosis of malignancy, at times without a clinical suspicion of severe abnormality, an interval of up to 691 days was registered before a malignant process was confirmed histologically. Furthermore, the influence of tumor grade and mode of therapy on the diagnostic accuracy of urinary cytology was evaluated. The accuracy of urinary cytology differed clearly between untreated and treated patients with both high and low grade tumors. Patients who received surgical therapy, radiotherapy and chemotherapy were grouped into three groups. Accuracy of cytologic diagnosis was calculated in relation to variations in therapy and in tumor grade. Minor differences in accuracy were found between specimens from patients after surgical therapy, chemotherapy and radiotherapy. The data from this study suggest that the diagnostic accuracy of urinary cytology is very much related to the histologic grade of bladder tumors, to pretreatment and posttreatment status, and only minimally to the mode of therapy itself (e.g., radiotherapy, chemotherapy or surgical therapy). The high percentage of cytologic diagnoses of atypia in specimens from patients undergoing chemotherapy and radiotherapy reflects the diagnostic problems.

Adenocarcinoma↗
PubMed1995

Using belief networks to enhance sharing of medical knowledge between sites with variations in data accuracy.

Differences in data definition between sites are a known obstacle to sharing of reminder-system rule sets. We identify another data characteristic--data accuracy--with implications for sharing. We reviewed the literature on data accuracy and found reports of high error rates for many data classes used by reminder systems (e.g., problem lists). The accuracy of other, equally important, data classes had not been characterized. Wide variations in accuracy between sites has been observed, suggesting that such differences may pose a previously unrecognized barrier to sharing of reminder rules. We propose a belief-network model for encoding reminder rules that explicitly models site-specific data accuracy and we discuss how encoding knowledge in this format may lower the cost and effort required to share reminder rules between sites.

Artificial Intelligence↗
PubMed1997

Accuracy of single-voxel proton MR spectroscopy in distinguishing neoplastic from nonneoplastic brain lesions.

PURPOSE: To measure the accuracy of single-voxel, image-guided proton MR spectroscopy in distinguishing normal from abnormal brain tissue and neoplastic from nonneoplastic brain disease. METHODS: MR spectroscopy was performed at 0.5 T with the point-resolved spectroscopic pulse sequence and conventional postprocessing techniques. Subjects consisted of a consecutive series of patients with suspected brain neoplasms or recurrent neoplasia and 10 healthy adult volunteers. Fifty-five lesions in 53 patients with subsequently verified final diagnoses were included. Spectra were interpreted qualitatively by visual inspection by nonblinded readers (prospectively) with the benefit of prior clinical data and imaging studies, and by blinded readers (retrospectively). The nonblinded readers interpreted the spectra as diagnostic or not, and, if diagnostic, as neoplastic or nonneoplastic. The blinded readers classified the spectra as diagnostic or not, and, if diagnostic, as normal or abnormal and as neoplastic or nonneoplastic (when abnormal). The sensitivity, specificity, positive and negative predictive values, and accuracy were calculated from blinded and nonblinded MR spectroscopy interpretations. A receiver operator characteristic (ROC) curve analysis was performed on blinded MR spectroscopy interpretations. RESULTS: The diagnostic accuracy averaged across four blinded readers in differentiating patients from control subjects was .96, while the area under the aggregate (pooled interpretations) ROC curve approached unity. Accuracy in the nonblinded and blinded discrimination of neoplastic from nonneoplastic disease was .96 and .83, respectively. The area under the aggregate ROC curve in the blinded discrimination of neoplasm from nonneoplasm was .89. CONCLUSIONS: Image-guided proton spectra obtained at 0.5 T from patients with suspected neoplasia can be distinguished from spectra in healthy control subjects, and neoplastic spectra can be distinguished from nonneoplastic spectra with a high degree of diagnostic accuracy.

Adult↗
PubMed1998

Equivocal notions of accuracy and genetic screening of the general population.

The explosive growth in genetic technology quickly will make possible an unprecedented number of tests for genetically based conditions. A necessary condition for the use of such tests without risk of harm to the patient is their accuracy. However, most discussions of test accuracy in the literature have equivocated between two importantly different meanings of the word. In particular, it must be remembered that a high analytic accuracy does not imply a high diagnostic accuracy. Questions about the diagnostic accuracy of genetic tests presently loom large because of our limited knowledge of the complex etiology of disease and the distribution within the general population of the causal factors involved. Our current inability to supply patients with accurate diagnosis based on genetic information, however, is less problematic when examined in the context of new reproductive technologies such as in vitro fertilization and intraplasmic sperm injection.

Attitude to Health↗
PubMed2003

The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration.

The quality of reporting of studies of diagnostic accuracy is less than optimal. Complete and accurate reporting is necessary to enable readers to assess the potential for bias in the study and to evaluate the generalisability of the results. A group of scientists and editors has developed the STARD (Standards for Reporting of Diagnostic Accuracy) statement to improve the reporting the quality of reporting of studies of diagnostic accuracy. The statement consists of a checklist of 25 items and flow diagram that authors can use to ensure that all relevant information is present. This explanatory document aims to facilitate the use, understanding and dissemination of the checklist. The document contains a clarification of the meaning, rationale and optimal use of each item on the checklist, as well as a short summary of the available evidence on bias and applicability. The STARD statement, checklist, flowchart and this explanation and elaboration document should be useful resources to improve reporting of diagnostic accuracy studies. Complete and informative reporting can only lead to better decisions in healthcare.

Algorithms↗