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PubMed1994

Childhood leukemia: diagnostic accuracy of bedside chest radiography for severe pulmonary complications.

PURPOSE: To determine the diagnostic accuracy of bedside chest radiography in patients who develop severe pulmonary complications while undergoing therapy for leukemia. MATERIALS AND METHODS: The authors studied 45 patients, aged 21 years and younger, who died of leukemia or of treatment complications and for whom autopsy findings were available. Pulmonary findings at autopsy comprised pneumonia (n = 25), adult respiratory distress syndrome (ARDS) (n = 16), hemorrhage (n = 38), infarction (n = 18), and leukemic cellular infiltration (n = 11). Four radiologists who were unaware of the autopsy diagnoses independently rated antemortem bedside chest radiographs. RESULTS: Diagnostic accuracy for each disease was as follows: ARDS, 0.81 +/- .03 (standard error); all pneumonias, 0.56 +/- .04; hemorrhage, 0.47 +/- .07; infarction, 0.50 +/- .12; and pulmonary leukemic cellular infiltration, 0.38 +/- .12. CONCLUSION: The specific radiographic appearance of ARDS permits excellent diagnostic accuracy.

Acute Disease↗
PubMed2005

Discordance analysis characteristics as a new method to compare the diagnostic accuracy of tests: example of complexed versus total prostate-specific antigen.

BACKGROUND: ROC curve analysis is used to compare the overall diagnostic accuracy of tests, but its application to subgroups selected by a concentration range of only one marker may show severe biases. We developed a new approach, which we have named discordance analysis characteristics (DAC). METHODS: The DAC method is based on a generalization of the McNemar test so that for a given pair of cutoff values only those patients are analyzed who are categorized differently by the two tests compared. The analyses are performed for all cutoff pairs that deliver identical sensitivities for both tests. We used data for total (tPSA) and complexed prostate-specific antigen (cPSA) from a recently published multicenter study to demonstrate the DAC method. RESULTS: The example shows that ROC analyses of subgroups can give contradictory results about the diagnostic accuracy of two markers, depending on the marker used for the selection of subgroups. The DAC method avoids artifacts attributable to questionable selection of subgroups and facilitates overall and local comparisons of the diagnostic accuracy of tests. The DAC results of the analyzed data set suggest that cPSA has higher diagnostic accuracy than does tPSA. CONCLUSIONS: The DAC method is a suitable tool for comparing the clinical usefulness of laboratory markers. The DAC method could be considered as an additional tool to ROC analysis and could replace comparative ROC analyses of diagnostic tests, especially within subgroups defined by only one of the markers.

Humans↗
PubMed2006

Age changes the diagnostic accuracy of mean profile and nadir growth hormone levels after oral glucose in postoperative patients with acromegaly.

BACKGROUND: This analytical, retrospective study was designed to select cut-off thresholds of mean GH levels during a diurnal profile and nadir GH levels after oral glucose tolerance test (OGTT) according to age to diagnose surgical remission of acromegaly. METHODS: One hundred forty-one patients (76 women, aged 44 +/- 15 years and 65 men, aged 43 +/- 13 years) were included in this study. For the purpose of this study, remission was based on insulin-like growth factor-I (IGF-I) levels in the normal range for age. Diagnostic accuracy was analysed by receiving-operator characteristics (ROC) curves in the entire series, and in young (20-40 years), middle-aged (41-60 years) and older patients (> 60 years), separately. RESULTS: Sixty patients (42.6%) had normal IGF-I levels after surgery. In the entire series, in young and in middle-aged patients, the ROC analysis showed that optimum cut-off for mean GH levels was 2.3 microg/l (diagnostic accuracy range, 94-97%) whereas that for nadir GH after OGTT were, respectively, 0.85, 0.9 and 0.8 microg/l (diagnostic accuracy range, 90-95%). In the older patients, the optimum cut-off selected for mean GH levels was 1.4 microg/l and that for nadir GH after OGTT was 0.5 microg/l (diagnostic accuracy, 100% for both). The comparative analysis of the ROC curves did not show any significant difference between mean GH and nadir GH after OGTT (P = 0.21). CONCLUSIONS: The criteria currently accepted for diagnosing post-surgical remission of acromegaly have high diagnostic accuracy only in the patients aged below 60 years. In older patients, lower cut-offs (i.e. = 1.4 microg/l for fasting GH and = 0.5 microg/l for nadir GH after OGTT) predict normal IGF-I levels. Mean GH levels during a diurnal profile have similar diagnostic accuracy of nadir GH levels after OGTT. This suggests that OGTT is not necessary to establish surgical cure.

Acromegaly↗
PubMed2002

[Diagnostic accuracy of cell-block or tissue-fragment histology and cytology by fine needle lung aspiration].

OBJECTIVE: Study on the diagnostic accuracy and value of cell block and tissue fragment preparations collected from lung fine needle aspiration (FNA). METHODS: A total of 187 FNA (22G) samples from the lungs with matched histological diagnosis were studied. Among them, the diagnosis made by depending on 124 cell block and fragment preparations were analyzed in comparing retrospectively with the diagnosis of 187 cases by smear preparations. RESULTS: (1) Of the 124 cell blocks cases, 89 cases were true positives, 22 cases were true negatives, 13 cases were false negatives and no false positives. Of the 187 smears cases, the figure were 136, 30, 19 and 2 cases respectively. The diagnostic accuracy of cell blocks was 87.3% in sensitivity, 100% in specificity, 89.5% in overall accuracy. The figures for smears were 87.7%, 93.8% and 88.8% respectively. (2) For malignant tumours, the histological typing accuracy of cell blocks was 93.3% (83/89), and to be 67.9% (91/134) by diagnosis depending on the smears (P < 0.01). For the benign lesions, the figures were 86.4% (19/22) and 60% (18/30) respectively (P < 0.05). (3) It was possible to obtain many minisections for further studies from cell blocks. Immunoperoxidase staining on minisections was reliable and agreed with those on the surgical specimens. CONCLUSIONS: The diagnostic accuracy of cell block is high, particularly in histological typing which approaches to that of the diagnosis made depending on the postoperative specimens. A combined use of smears and cell block is recommended which may raise further the diagnostic accuracy.

Adolescent↗
PubMedDate not supplied

Impact of intravascular enhancement, heart rate, and calcium score on diagnostic accuracy in multislice computed tomography coronary angiography.

PURPOSE: To assess the effect of intravascular enhancement, heart rate, and calcium score on diagnostic accuracy in the detection of significant coronary artery stenosis using 16-row multislice computed tomography (MSCT). MATERIALS AND METHODS: One hundred patients (88 males; 59+/-11 years) with suspected coronary artery disease who had undergone conventional coronary angiography (CA) and MSCT-CA were retrospectively enrolled for the study. Patients underwent a MSCT-CA, with the following protocol: collimation 16x0.75 mm, gantry rotation time 420 ms, feed/rotation 2.8 mm, kV 120, mAs 400-500. The protocol for contrast material administration was 100 ml of Iodixanol 320 mgI/ml at 4 ml/s and the scan delay was defined with a bolus tracking technique. In all patients vascular enhancement was measured in the aortic root, and in the left and right coronary arteries. The average vascular enhancement was used to divide the population in two groups of 50 patients each, one with lower enhancement (Low), and one with higher enhancement (High). In the two groups diagnostic accuracy (per coronary segment) for the detection of significant stenosis (= or >50% lumen reduction) was evaluated in vessels = or >2 mm in diameter using quantitative CA as the reference standard. The differences in diagnostic accuracy were compared with a Chi-square test and a p<0.05 was considered significant. RESULTS: Of the total 1116 segments (= or >2 mm lumen diameter), 173 presented significant stenosis. The sensitivity and specificity for the assessment of significant stenosis were 89.4% and 93.3% vs 94.3% and 97.4% in the presence of increasing intravascular enhancement, 92.8% and 96.7% vs 91.1% and 93.9% in the presence of increasing heart rate, and 89.7% and 97.6% vs 93.3% and 92,8% in the presence of an increasing calcium score. CONCLUSIONS: Increasing intravascular enhancement significantly improves diagnostic accuracy in MSCT-CA. A higher heart rate lowers the specificity in the detection of significant obstructing lesions of the coronary artery. An increasing calcium score determines a lower specificity and a higher sensitivity.

Aged↗
PubMed2005

Diagnostic accuracy of multislice computed tomography coronary angiography is improved at low heart rates.

PURPOSE: Assess the effect of heart rate on diagnostic accuracy for the detection of significant coronary artery stenosis using 16-row multislice computed tomography (MSCT). MATERIAL AND METHODS: About 120 patients (105 males; 59+/-11 years) with suspected coronary artery disease who underwent conventional coronary angiography (CA) and MSCT-CA were retrospectively enrolled for the study. Patients underwent a MSCT-CA (Sensation 16, Siemens, Germany), with the following protocol: collimation 16 x 0.75 mm, gantry rotation time 420 ms, feed/rotation 3.0 mm, kV 120, mAs 400-500. The protocol for contrast material administration was 100 ml of Iodixanol (Visipaque 320 mg l/ml, Amersham, UK) at 4 ml/s and the delay was defined with a bolus tracking technique. In all patients the mean heart rate (HR) during the scan was used as a criteria to divide the population in two groups of 60 patients each. In one group (Low HR) the 60 patients with lower heart rates, and in the other group (High HR) the patients with higher heart rates. In the two groups diagnostic accuracy (per coronary segment) for the detection of significant stenosis (>or=50% lumen reduction) was evaluated in vessels >or=2 mm of diameter using quantitative CA as reference standard. The difference in diagnostic accuracy were compared with a Chi(2) test and a p<0.05 was considered significant. RESULTS: There was no significant difference between the two groups regarding age, gender, weight, mean intravascular attenuation, and calcium score. Overall 1,310 (652 for Low HR and 658 for High HR) segments with 219 (105 for Low HR and 114 for High HR) significant lesions were available for the analysis. The average heart rate was 52+/-4 HU and 63+/-5 HU for Low HR and High HR, respectively (p<0.001). The sensitivity and specificity were 92 and 96% for Low HR and 90 and 92% for High HR (p<0.05). There were 22 vs. 44 false positives, and 8 vs. 12 false negatives in the Low HR and High HR, respectively. CONCLUSION: Increasing HR significantly deteriorates diagnostic accuracy in MSCT-CA.

Chi-Square Distribution↗
PubMedDate not supplied

High diagnostic accuracy of cytologic smears of central nervous system tumors. A 15-year experience based on 4,172 patients.

OBJECTIVE: To investigate the diagnostic accuracy and current role of intraoperative cytologic smears of central nervous system tumors. STUDY DESIGN: Retrospective analysis of 4,172 patients operated on during 1985-1999, with 3,541 intraoperative smears performed during open procedures and 631 during stereotactic biopsies. RESULTS: Complete correlation with the final diagnosis was achieved in a mean of 89.8% (range, 83-93.7% per year). Diagnostic accuracy increased to 95% on average (range, 91.5-96.7% per year) when cases of partial correlation, mainly due to grading deviations, were included. The most accurate intraoperative diagnoses were obtained in cases of meningioma (97.9%), metastasis (96.3%) and glioblastoma (95.7%). A significant reduction in diagnostic accuracy was observed in cases of oligodendroglioma (80.9%) and ependymoma (77.7%). Besides diagnosis and grading, smear cytology provided resection guidance in cases of well-delineated tumors. CONCLUSION: Intraoperative smears in neurosurgery are easy to obtain and inexpensive and have high diagnostic accuracy. In addition to stereotactic biopsy procedures, intraoperative smears permit reliable intraoperative guidance during lesion targeting and resection.

Biopsy↗
PubMed2006

Diagnostic accuracy of fracture detection in suspected non-accidental injury: the effect of edge enhancement and digital display on observer performance.

AIM: To compare the effect of varying degrees of edge enhancement and method of digital image display on fracture detection in suspected non-accidental injury (NAI). MATERIALS AND METHODS: Fifty radiographs from post-mortem skeletal surveys in 13 children with suspected NAI were selected. Images were obtained using a Fuji 5000R computed radiography system. Hard copies were printed with edge enhancement factors 0, 0.5 and 1.2. Images (edge enhancement 0.5) were also displayed on a 1K(2) monitor. Six observers independently evaluated all 200 images for the presence of abnormality. Observers also scored each image for visualization of soft tissues, visualization of trabecular markings and overall image quality. The paired Student's t-test and location receiver operating curve (ROC) analysis were used to compare quality scores and diagnostic accuracy of each display method. Individual and pooled true-positive rates (sensitivity) were determined. For the purposes of ROC analysis, histology was taken as the gold standard. RESULTS: There was no difference in duration of hard and soft-copy reading sessions (p=0.76). After image manipulation soft-copy radiographs scored significantly better for image quality than hard copy (p<0.0001). Pooled observer sensitivity (at a specificity of 90%) was below 50% for all display methods. Diagnostic accuracy varied significantly between observers. Diagnostic accuracy of individual observers was not affected by display method. CONCLUSION: In suspected NAI, diagnostic accuracy of fracture detection is generally low. Diagnostic accuracy appears to be affected more by observer-related factors than by the method of digital image display.

Child Abuse↗
PubMed1986

[Serum thyroglobulin in the diagnosis of metastases of differentiated thyroid cancer. Effect of suppressive thyroid hormone substitution on the diagnostic accuracy of thyroglobulin values].

The diagnostic accuracy of serum thyroglobulin (S-TG) determination as measured under endogenous thyrotropin(TSH)stimulation (ETS) has been investigated in 372 patients with completed therapy for differentiated thyroid cancer. In 51 of these (13.7%) S-TG could be detected by means of the IRMA-technique. In 34 S-TG determination was additionally performed during suppressive thyroxine therapy (SSH): S-TG in SSH was significantly lower as compared with S-TG in ETS (p less than 0.001). In seven cases with proven metastases S-TG values were pushed below the minimal detection level by SSH. Tumor manifestations with suppressible S-TG were significantly smaller (mean = 5 ccm, range 1-25 ccm) than those with non-suppressible S-TG (mean = 90 ccm, range 11-125 ccm, p less than 0.005) and displayed a papillary histology. There was a moderate correlation between S-TG concentration and tumor volume (r = 0.71; p less than 0.001). 21% (n = 66) of patients with undetectable S-TG in ETS showed 131I-uptake in the thyroid region; 2% (n = 7) had proven metastases. Sensitivity of S-TG determination for the detection of metastases amounted to 82.5% in ETS and 53.3% in SST, specificity was 94.6% in ETS and 99.7% in SST. It is concluded that small metastases of papillary thyroid carcinomas may escape S-TG screening more readily than follicular carcinoma metastases when S-TG concentrations are measured during thyroxine treatment.

Adenocarcinoma↗
PubMed2006

Diagnostic accuracy of noninvasive fetal Rh genotyping from maternal blood--a meta-analysis.

OBJECTIVE: The purpose of this study was to determine the reported diagnostic accuracy, the validity, and the current limitations of fetal Rh genotyping from peripheral maternal blood based on the existing English-written publications. STUDY DESIGN: A search of the English literature describing fetal RhD determination from maternal blood was conducted. From each study, we determined the number of samples tested, fetal RhD genotype, the source of the fetal DNA (maternal plasma, serum, or fetal cells), gestational age, and confirmation of fetal Rh type. The presence of alloimmunization and exclusions of tested samples were noted. For the meta-analysis we calculated composite estimates using 2 random effects models, weighted GLM and Bayesian. Sensitivity, specificity, positive and negative predictive values were calculated. RESULTS: We identified 37 English-written publications that included 44 protocols reporting noninvasive Rh genotyping using fetal DNA obtained from maternal blood on a total of 3261 samples. A total of 183 (183/3261, 5.6%) samples were excluded from the meta-analysis. The overall diagnostic accuracy after exclusions was 94.8%. The gestational ages ranged between 8 and 42 weeks gestation. Maternal serum and plasma were found to be the best source for accurate diagnosis of fetal RhD type in 394/410 (96.1%) and 2293/2377 (96.5%), respectively. There were 719/783 (91.8%) alloimmunized patients that were correctly diagnosed. There were 16 studies that reported 100% diagnostic accuracy in their fetal RhD genotyping. CONCLUSION: The diagnostic accuracy of noninvasive fetal Rh determination using maternal peripheral blood is 94.8%. Its use can be applicable to Rh prophylaxis and to the management of Rh alloimmunized pregnancies. Improvements of the technique and further study of structure and rearrangements of the RhD gene may improve accuracy of testing and enable large-scale, risk-free fetal RhD genotyping using maternal blood.

DNA↗
PubMed1989

Diagnostic accuracy of sialic acid in the diagnosis of malignant ascites.

The authors evaluated the diagnostic accuracy of sialic acid and its lipid-bound fraction in ascites and compared these tests with others (fibronectin, cholesterol) recently claimed as valuable in the differential diagnosis of ascites. Fibronectin yielded the best diagnostic accuracy (85%) with no false-positive and 37% of false-negative (10/27). The authors also found higher concentration of sialic acid in malignant ascites than in nonmalignant ascites (P less than 0.001) and, taking 300 mg/l as the cutoff value, the false-positive rate was 10% (four of 40), the false-negative rate 30% (eight of 27), and the overall diagnostic accuracy 82%, comparable to that of the fibronectin. The authors conclude that both fibronectin and sialic acid determinations in ascites may be regarded as accurate markers of neoplastic involvement of the peritoneum, although no test is useful in the ascites with hepatocellular carcinoma and cirrhosis of the liver.

Ascites↗
PubMed1998

Meta-analyses of studies of the diagnostic accuracy of laboratory tests: a review of the concepts and methods.

OBJECTIVE: To provide practicing pathologists and other laboratory professionals with the necessary background for reading and evaluating published reports of meta-analyses of studies of the diagnostic accuracy of laboratory tests. STUDY SELECTION: English language literature, 1980 to present, pertaining to the rationale, objectives, and interpretation of meta-analyses of randomized controlled trials, and meta-analyses of studies of the diagnostic accuracy of laboratory tests. CONCLUSIONS: Meta-analysis has several applications in the investigation of the diagnostic accuracy of laboratory tests. It can improve the quality of future primary studies by drawing attention to the methodologic deficiencies of existing reports; it can identify reasons for the variation in the results of those reports; and it can generate valid summary estimates of the diagnostic accuracy of laboratory tests based on all completed investigations, providing that the available primary studies are of high scientific validity. Several statistical techniques for integrating data from reports on diagnostic test accuracy have either been developed or are under development, but meta-analysis is often limited by the poor quality of the primary studies and the effect of publication bias. Meta-analysis can evolve into a reliable tool for assessing the accuracy of laboratory tests if both investigators and editors strive to improve the quality of the primary studies and to reduce the extent of publication bias in this area of the literature.

Clinical Laboratory Techniques↗
PubMed2003

Diagnostic accuracy of 2-[fluorine-18]fluro-2-deoxy-D-glucose positron emission tomography imaging in nonsquamous tumors of the head and neck.

PURPOSE: To evaluate the diagnostic accuracy of 2-[fluorine-18]fluro-2-deoxy-D-glucose positron emission tomography (FDG-PET) for detecting nonsquamous tumors of the extracranial head and neck (NSTHN). MATERIALS AND METHODS: The records of all patients with suspected or proven NSTHN undergoing PET imaging in our institution over a 12-year period were reviewed. Forty-four patients (24 males and 20 females; age range, 6-81 years; mean age, 51.2 years) were classified into 3 main groups: thyroid tumors (n = 19), salivary gland tumors (n = 7), and miscellaneous lesions (n = 18). The PET findings for each individual group with respect to the primary site, cervical nodal and distant metastases, were correlated with histopathology or follow-up (2-year minimum) RESULTS: The overall diagnostic accuracy of FDG-PET for all NSTHN was 86%, However, the diagnostic accuracy varied for the histologic subtype (thyroid, salivary, miscellaneous) and the area being evaluated (primary site, nodal metastases, distant metastases). CONCLUSION: There is variable diagnostic accuracy of FDG-PET in detecting different histologic subtypes of NSTHN. This information should be taken into consideration when considering PET for evaluation of NSTHN.

Adolescent↗
PubMed1994

Volumetric high-resolution CT in the diagnosis of interstitial lung disease and bronchiectasis: diagnostic accuracy and radiation dose.

OBJECTIVE: The purpose of this study was to evaluate the diagnostic accuracy and radiation dose of volumetric high-resolution CT in the diagnosis of interstitial lung disease and bronchiectasis when four contiguous sections were acquired at each of three levels. The potential benefits were weighed against the increased radiation dose of multiple scans. SUBJECTS AND METHODS: High-resolution CT scans of four contiguous sections were obtained at each of three locations (the aortic arch, the carina, and 2 cm above the diaphragm) in 50 consecutive patients (mean age, 44 years old) with known or suspected interstitial lung disease or bronchiectasis who were referred for evaluation with high-resolution CT. Each individual scan was analyzed for the presence of motion-induced streaking, blurring, or doubling. The diagnostic information contained in each set of four scans was compared with that contained in the first of the four scans in the set. RESULTS: Motion degraded at least one of the four images in each set in 69 (46%) of 150 volumetric acquisitions. When the full set of four images was considered instead of just the first scan from the set, the number of motion-free studies in patients with suboptimal respiratory suspension was increased by 40% (from 99 to 139). Diagnostic accuracy was improved as more features were identified on contiguous scans: the sensitivity of the first scan compared with that of the complete set of four scans was 84% for the detection of bronchiectasis, 97% for ground-glass opacity, 88% for honeycombing, 88% for septal thickening, and 86% for nodular opacities. Although the integral radiation exposure for a set of four CT scans was 2.8 times that of a single scan obtained with standard technique, peak skin exposure was unchanged. Slightly increased image noise with the reduced technique compromised diagnostic ability in 6% of studies. CONCLUSION: The use of volumetric high-resolution CT increased diagnostic accuracy, particularly for bronchiectasis at the lung bases, without increasing peak skin radiation exposure. With the availability of four contiguous scans per anatomic level, the subjective confidence in interpretation and number of motion-free studies also increased.

Adult↗
PubMed1999

Diagnostic accuracy with US: remote radiologists' versus on-site radiologists' interpretations.

PURPOSE: To compare the diagnostic accuracy of radiologists interpreting static ultrasonographic (US) images electronically transmitted to an academic medical center (remote radiologists) with that of radiologists performing "hands-on" US at a community-based outpatient site (on-site radiologists). MATERIALS AND METHODS: During 8 months, 80 patients underwent pelvic US at a community-based outpatient site. Images were electronically transmitted to a remote medical center as they were acquired at the community site and were printed on a laser printer identical to the one used at the outpatient site. The reference standard for correct diagnosis was based on histopathologic findings (n = 13), additional imaging results (n = 34), or review by a second independent observer (n = 33). Both an on-site and a remote radiologist interpreted the images, and their interpretations were rated as agree, both correct; agree, both incorrect; or disagree. Cases of disagreement were rated as major or minor. RESULTS: On-site and remote radiologists agreed in 69 of 80 patients (86%), and both radiologists were correct in all of these cases. There were 10 minor discrepancies and one major discrepancy. The diagnostic accuracies of the one-site and remote radiologists were 92% and 94%, respectively. CONCLUSION: High levels of diagnostic accuracy can be achieved by radiologists interpreting static US images. Strict protocols and excellent communication between the radiologist and sonographer are necessary to avoid diagnostic errors.

Academic Medical Centers↗
PubMed1976

Direct measurement of the effect of film miniaturization on diagnostic accuracy.

A method for directly measuring the reduction in diagnostic accuracy incurred by altering original radiographs was applied to evaluate a 35 mm film system. A total of 4,290 readings of 2,145 proved cases were collected. Analysis of the results indicate that the 35 mm system reduced diagnostic accuracy by about 2.3% +/- 2.4% at a 95% confidence level. The same method can be used to evaluate other photographic reduction systems, television displays, enhancement schemes, or even the importance of clinical data in roentgenographic interpretation.

Diagnostic Errors↗
PubMed2000

Proton MR spectroscopy and preoperative diagnostic accuracy: an evaluation of intracranial mass lesions characterized by stereotactic biopsy findings.

BACKGROUND AND PURPOSE: MR imaging has made it easier to distinguish among the different types of intracranial mass lesions. Nevertheless, it is sometimes impossible to base a diagnosis solely on clinical and neuroradiologic findings, and, in these cases, biopsy must be performed. The purpose of this study was to evaluate the hypothesis that proton MR spectroscopy is able to improve preoperative diagnostic accuracy in cases of intracranial tumors and may therefore obviate stereotactic biopsy. METHODS: Twenty-six patients with intracranial tumors underwent MR imaging, proton MR spectroscopy, and stereotactic biopsy. MR spectroscopic findings were evaluated for the distribution pattern of pathologic spectra (NAA/Cho ratio < 1) across the lesion and neighboring tissue, for signal ratios in different tumor types, and for their potential to improve preoperative diagnostic accuracy. RESULTS: Gliomas and lymphomas showed pathologic spectra outside the area of contrast enhancement while four nonastrocytic circumscribed tumors (meningioma, pineocytoma, metastasis, and germinoma) showed no pathologic spectra outside the region of enhancement. No significant correlation was found between different tumor types and signal ratios. MR spectroscopy improved diagnostic accuracy by differentiating infiltrative from circumscribed tumors; however, diagnostic accuracy was not improved in terms of differentiating the types of infiltrative or circumscribed lesions. CONCLUSION: MR spectroscopy can improve diagnostic accuracy by differentiating circumscribed brain lesions from histologically infiltrating processes, which may be difficult or impossible solely on the basis of clinical or neuroradiologic findings.

Adult↗
PubMed1999

The diagnostic accuracy of Danish GPs in the diagnosis of pigmented skin lesions.

BACKGROUND: The GP often has a primary function in assessing pigmented skin lesions in Denmark. No data are available on the diagnostic accuracy of this process. OBJECTIVE: We aimed to study the sensitivity, specificity and positive prognostic value of the diagnosis made by 27 trained or trainee GPs. METHOD: We tested the diagnostic accuracy of the viewing of colour slides of pigmented skin lesions under standardized conditions at a seminar on skin cancer. Diagnostic accuracy was determined only for the clinically relevant diagnosis of benign or malignant. RESULTS: The median diagnostic accuracy (sensitivity) for the group as a whole was 0.75 (95% CI 0.65-0.80), the specificity was 0.70 (95% CI 0.68-0.79) and the positive predictive value 0.70 (95% CI 0.62-0.77). CONCLUSION: These values are comparable with previously published figures for trainee dermatologists, and it is therefore concluded that ongoing interest rather than basic training is the major determinant for clinical acumen.

Adult↗