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At least 235 records · Page 13Linked to original sources
PubMed1994

Diagnostic performance of magnetic resonance imaging for the diagnosis of rotator cuff tears using supplemental images in the oblique sagittal plane.

RATIONALE AND OBJECTIVES: The authors evaluated the diagnostic utility of supplemental imaging in the oblique sagittal (OS) plane for the magnetic resonance imaging (MRI) diagnosis of rotator cuff tears. METHODS: Two radiologists with varying levels of MRI experience blindly reviewed shoulder MR examinations of 50 patients for rotator cuff tears. Shoulder examinations were interpreted twice, initially using only double-echo spin-echo images obtained in the oblique coronal (OC) plane and later using double-echo spin-echo images obtained in the both the OC and OS planes. Tears were characterized according to size, location, and extent, and levels of diagnostic confidence were evaluated. RESULTS: Sensitivity and specificity of MR for the diagnosis of rotator cuff tear was 85% and 80%, respectively, with the OC series increasing to 95% and 93%, respectively with OCOS scans. However, these increases were not statistically significant. Receiver operating characteristic (ROC) curves suggest a trend toward increased diagnostic confidence when supplemental OS scans are available, especially for the less experienced reader. Characterization of rotator cuff tears was not improved with additional OS images. CONCLUSIONS: Supplemental OS scans did not demonstrate a definite improvement in diagnostic accuracy for rotator cuff tears compared to OC scans alone. Estimations based on sample size calculations indicate that a much larger population of patients would be needed to show a statistically significant difference.

Humans↗
PubMed1996

[Diagnostic accuracy of 201T1 SPECT.MRI in brain diseases and inter-reader variance of diagnostic performance].

Fifteen-four studies of 201T1 brain tumor SPECT were independently interpreted by 9 nuclear medicine physicians with and without reference magnetic resonance images in 2 separate sessions to define an effect of referring images, and inter-observer variations. The physicians were requested to detect foci of abnormal deposits, and to discriminate whether they were malignant or not according to 5-grade scaling of subjective diagnostic confidence. Receiver-operating characteristics (ROC) analysis was performed. Mean sensitivity for presence of lesions (SEP), and sensitivity and specificity for malignancy of 201T1 SPECT were 84, and 53 and 55%, which were changed to 94, and 74 and 55% after referring to the MR images. The SFP was significantly improved (p < 0.05), but sensitivity and specificity for malignancy, assessed by areas under the ROC curves, were not significantly improved. Inter-observer variation of the SFP was significantly reduced with addition of the referring MR images. Cerebral lobar localization of lesions by SPECT showed great inter-observer variations (true localization ranged from 30 to 68.4%). It is concluded that 201T1 brain tumor SPECT has moderate sensitivity and specificity for malignancy, which is not improved by addition of anatomical reference images, that additional MR images reduce inter-observer variation of confidence on lesion presence, and that SPECT localization of lesions has great inter-observer variations.

Adolescent↗
PubMed2000

Diagnostic performance of two mental status tests in the older chinese: influence of education and age on cut-off values.

AIMS: To (1) establish the clinical usefulness of the 10-item Abbreviated Mental Test (AMT) and the 18-item Chinese Mini-Mental Status Examination (CMMSE) for detecting cognitive impairment associated with dementia in the elderly Chinese; (2) determine how the tests' optimal cut-off scores varied with the patients' educational level and age; and (3) evaluate which was the more accurate test. METHODS: 151 cognitively-healthy, community dwelling elderly Chinese subjects and 95 elderly Chinese outpatients with dementia were administered the AMT and CMMSE. Receiver-Operating Characteristic (ROC) analysis was used to determine the tests' optimal cut-off scores for each of the education-by-age subgroups and their areas-under-the-curve were compared non-parametrically to evaluate which test was more accurate. RESULTS: Both the AMT and CMMSE could identify cognitive impairment accurately, but higher cut-off values were necessary for the younger and more educated cohort, while lower values were adequate for the older and less educated subgroup. The AMT appeared to reach a ceiling effect in the more educated categories. The diagnostic accuracies of the two instruments were statistically equivalent; there was a trend, however, for the CMMSE to be performing better in the more educated subgroups. CONCLUSIONS: To maximise the diagnostic efficiency of these two clinically useful mental status tests, it is important to adjust their cut-off scores for the patients' education and age. Though no clear superiority of either instrument was established in this study, we recommend the AMT for patients with 0-6 years of education, whereas for those with greater levels of literacy, we think it better to administer the CMMSE.

Age Factors↗
PubMed2003

Diagnostic performance and retention of acquired skills after dermatology elective.

BACKGROUND: The dermatology elective often constitutes the future physician's only exposure to dermatologic practice. Cost-benefit considerations dictate that the elective enables the students to acquire useful diagnostic expertise in the short time period available, and that this expertise is not rapidly forgotten after completion of the elective. METHODS: In order to determine the efficacy of a 2-week dermatology elective in promoting diagnostic skills and to ascertain the preservation of the acquired expertise, kodachrome slide-based multiple-choice examinations were administered to 84 sixth year medical students at the beginning (pre-test) and completion (post-test) of the elective. The long-term retention of diagnostic skills was evaluated by re-testing 4-9 months after completion of the elective (follow-up test). RESULTS: The mean scores of correct answers at the pre- and post-test were 39.73% and 72.46%, respectively. The mean score at the follow-up test for students with a previous dermatology elective was 80.22%, compared with a score of 46.00% for students who did not participate in the elective. CONCLUSIONS: The 2-week dermatology elective significantly improved the diagnostic skills of the participants, and the knowledge obtained during the elective was retained for at least 4-9 months.

Clinical Clerkship↗
PubMed2005

Variation in the diagnostic performance of D-dimer for suspected deep vein thrombosis.

BACKGROUND: Numerous studies have evaluated the accuracy of D-dimer in diagnosing suspected deep vein thrombosis (DVT), but results are conflicting. AIM: To overview estimates of the diagnostic accuracy of D-dimer and identify causes of variation. DESIGN: Systematic review, meta-analysis and meta-regression. METHODS: We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, citation lists, and contacted manufacturers. We selected studies that compared D-dimer to a reference standard in patients with suspected DVT. Data were analysed by random effects meta-analysis and meta-regression. RESULTS: We included 97 studies reporting 198 assays in 99 different patient groups. Overall estimated sensitivity and specificity of D-dimer were 90.5% and 54.7%, but both estimates were subject to significant heterogeneity (p < 0.001). Meta-regression identified that some heterogeneity was explained by study setting, exclusion criteria, whether recruitment was consecutive or the study prospective, whether D-dimer and the reference standard were measured blind, and whether the D-dimer threshold was determined a priori. Sensitivity and specificity also varied between ELISA (94% and 45% respectively), latex (89% and 55%) and whole blood agglutination assays (87% and 68%). Sensitivity was higher for proximal than distal DVT. Specificity was dependent upon whether clinical probability of DVT was high (specificity 51%), intermediate (67%) or low (78%). DISCUSSION: D-dimer has good sensitivity, but poor specificity, for DVT. Estimates are subject to substantial heterogeneity from various sources. D-dimer specificity appears to be strongly dependent upon the pre-test clinical probability of DVT.

Antifibrinolytic Agents↗
PubMed2001

Comparative evaluation of the diagnostic performance of the BTA stat test, NMP22 and urinary bladder cancer antigen for primary and recurrent bladder tumors.

PURPOSE: We compared overall sensitivity and specificity of the urinary bladder cancer antigen enzyme-linked immunosorbent assay (UBC, IDL Biotech, Sollentuna, Sweden), BTA stat test (Bion Diagnostic Sciences, Inc., Redmond, Washington) and NMP22 test kit (Matritech, Newton, Massachusetts), and the differential sensitivity regarding the histological pattern of tumors. MATERIALS AND METHODS: A total of 213 patients with clinical and/or imaging signs of bladder cancer provided a single voided urine sample for the bladder cancer antigen, BTA stat test and NMP22 before cystoscopy. Of these patients 95 were monitored for superficial bladder cancer, while the remaining 118 had no history of bladder cancer. All detected bladder tumors or suspicious lesions were resected transurethrally. A group of 21 age and sex matched healthy volunteers were also evaluated with the same tests. RESULTS: Bladder cancer was confirmed histologically in 118 patients, of whom primary and recurrent tumors were in 68 and 50, respectively. The optimal cutoffs calculated with receiver operating characteristics curves were 8 units per ml. for NMP22 and 12 microg./l. for bladder cancer antigen. Overall sensitivity and specificity were 72.9% and 64.6% for the BTA stat test, 63.5% and 75.0% for NMP22, and 80.5% and 80.2%, respectively, for bladder cancer antigen. Bladder cancer antigen proved significantly more sensitive than NMP22 for detecting bladder cancer (p = 0.001) but not more than the BTA stat test, while the specificity of it was significantly higher than that of the BTA stat test (p = 0.009). Bladder cancer antigen had a sensitivity of 80.7% for stage Ta tumors, which was significantly higher than NMP22 (52.6%, p = 0.001) and the BTA stat test (57.9%, p = 0.01). In grade I tumors the sensitivity of bladder cancer antigen (70%) did not differ significantly than that of the BTA stat test (50%) and NMP22 (50%, p = 0.14). Bladder cancer antigen had the least false-positive results in patients with a history of bladder cancer and negative cystoscopy, and those with urological disease other than bladder cancer. CONCLUSIONS: Our data indicate that bladder cancer antigen may be a more potent diagnostic marker for bladder cancer than NMP22 and the BTA stat test based on the higher sensitivity for detecting low stage and low grade tumors, and the higher specificity. The contribution of these tests for detection of bladder cancer should still be considered adjunctive to cystoscopy.

Adult↗
PubMed2003

Diagnosis of pigmented skin lesions by dermoscopy: web-based training improves diagnostic performance of non-experts.

BACKGROUND: Dermoscopy has been shown to enhance the diagnosis of melanoma. However, use of dermoscopy requires training and expertise to be effective. OBJECTIVES: To determine whether an Internet-based course is a suitable tool in teaching dermoscopy, and to evaluate the diagnostic value of pattern analysis and diagnostic algorithms in colleagues not yet familiar with this technique. METHODS: Sixteen colleagues who were not experts in dermoscopy were asked to evaluate the dermoscopic images of 20 pigmented skin lesions using different diagnostic methods (i.e. pattern analysis, ABCD rule, seven-point checklist and Menzies' method), before and after an Internet-based training course on dermoscopy. Mean +/- SEM sensitivity, specificity and diagnostic accuracy, and kappa (kappa) intraobserver agreement were evaluated for each diagnostic method before and after training for the 16 participants. Differences between mean values were assessed by means of two-tailed Wilcoxon rank-sum tests. RESULTS: There was a considerable improvement in the dermoscopic melanoma diagnosis after the Web-based training vs. before. Improvements in sensitivity and diagnostic accuracy were significant for the ABCD rule and Menzies' method. Improvements in sensitivity were also significant for pattern analysis, whereas the sensitivity values were high for the seven-point checklist in evaluations both before and after training. No significant difference was found for specificity before and after training for any method. There was a significant improvement in the kappa intraobserver agreement after training for pattern analysis and the ABCD rule. For the seven-point checklist and Menzies' method there was already good agreement before training, with no significant improvement after training. CONCLUSIONS: We demonstrated that Web-based training is an effective tool for teaching dermoscopy.

Clinical Competence↗
PubMed2001

Diagnostic performance of trauma US in identifying abdominal or pelvic free fluid and serious abdominal or pelvic injury.

RATIONALE AND OBJECTIVES: This study assessed the ability of a six-point trauma ultrasound (US) evaluation (a) to identify the presence of free fluid in the abdomen or pelvis, with computed tomography (CT) and laparotomy used as diagnostic standards and (b) to predict the presence of abdominal or pelvic injury, particularly injury requiring surgical intervention. MATERIALS AND METHODS: Of 156 patients who underwent US evaluation for free fluid after sustaining blunt and penetrating trauma, 147 were entered into the prospective study and underwent follow-up CT and/or laparotomy (n = 79), in-hospital observation, or outpatient examination. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of US for identifying abdominal or pelvic free fluid were 69%, 100%, 100%, 95%, and 95%, respectively. The corresponding values for predicting abdominal and pelvic injury on the basis of free fluid status alone were 57%, 99%, 80%, 96%, and 95%, respectively. Performing repeated US examinations in patients with deteriorating clinical status decreased the false-negative rate by 50%, increasing the sensitivity for free fluid detection to 85% and the negative predictive value to 97%. Similarly, the sensitivity and negative predictive value for detection of injury increased to 71% and 97%, respectively. A learning curve was also observed, with 67% of the false-negative findings occurring in the first 3 months of the 19-month study. CONCLUSION: A six-point trauma US evaluation can reliably identify abdominal and pelvic free fluid, which can be a reliable indicator of abdominal or pelvic injury. Scanning conditions must be optimized, and the approach to clinical management must be cautious.

Abdominal Injuries↗
PubMed1987

Diagnostic performance of basal free cortisol/18-hydroxy-11-deoxycorticosterone (18-OH-DOC) ratio in endogenous depression: comparison with the dexamethasone suppression test.

We assessed the 8:00 AM ratio of free cortisol/18-hydroxy-11-deoxycorticosterone (18-OH-DOC) in 56 endogenous depressive inpatients and in 22 normal volunteers. A ratio higher than 40 was associated with a diagnostic sensitivity for endogenous depression of 75%, a specificity of 95.5%, and a diagnostic confidence of 97.7%. These diagnostic results were at least equivalent to the Dexamethasone Suppression Test (DST) using a cortisol cut-off limit of 5 micrograms/dl. This may thus represent a simpler procedure than the DST in the diagnostic analysis of endogenous depression.

18-Hydroxydesoxycorticosterone↗
PubMed2004

Diagnostic performance of light-induced fluorescence endoscopy for gastric neoplasms.

BACKGROUND AND STUDY AIM: Malignant tumors generate autofluorescent patterns that differ from those of normal tissue. However, whether autofluorescent diagnosis could be genuinely useful in screening for gastric neoplasms has not been well investigated in clinical practice. Accordingly, we retrospectively studied our experience with this diagnostic technique for various gastric lesions and assessed its diagnostic utility. PATIENTS AND METHODS: Autofluorescence diagnosis of 109 gastric lesions in 79 patients was done, without knowledge of the diagnosis by conventional white light endoscopy, retrospectively and independently by three endoscopists with 6 years', two years' and no experience of the technique. After examination of the interobserver bias in the assessment of autofluorescent pseudocolor in light-induced fluorescence endoscopy (LIFE), the relationship between pseudocolor and characteristics of gastric lesions (including histology, macroscopic type, and depth of invasion) were investigated. RESULTS: The kappa statistic for agreement in pseudocolor diagnosis between the three endoscopists was 0.71. The assessment of pseudocolor by all of the observers was in agreement in 67 of the total of 109 lesions (61.5 %). Experience with the LIFE technique did not improve the accuracy of pseudocolor determination. All of the cancers, 87.5 % of the adenomas, and 50.9 % of the benign lesions were recognized as having an abnormal autofluorescent image. None of the gastric cancers and 49.1 % of the benign lesions were evaluated as having a normal autofluorescence image. The histopathological and macroscopic types of tumors and their depths of invasion were not reflected in the autofluorescence diagnosis. CONCLUSIONS: LIFE provided a sensitivity of 96.4 % and specificity of 49.1 %, suggesting that this technique has limited clinical utility, regardless of the merits of acceptable interobserver bias and lack of necessity for experience with this technique.

Adenocarcinoma↗
PubMed2003

The need for built-in validation of surveillance data so that changes in diagnostic performance of post-mortem meat inspection can be detected.

Time trends in animal-disease surveillance often are evaluated on the basis of crude estimates of apparent prevalence. In addition to possible changes in the true prevalence of the condition, changes in apparent prevalence over time might reflect changes in sensitivity and/or specificity of the diagnostic classification used. To illustrate this, comparative post-mortem meat inspection data from four Danish slaughter plants sampled in 1993-1994 and 1997-1998 were used to obtain latent-class model estimates of the sensitivity and specificity of traditional and extended post-mortem meat inspection of visceral and parietal chronic pleuritis (CP), respectively.True prevalence of CP was estimated for each study period and slaughter plant by latent-class models. Estimated sensitivities of traditional post-mortem meat (TPM) inspection ranged from 28.8 to 61.4% (1993-1994) and 39.2 to 87.3% (1997-1998). An increase in sensitivity with time was seen for all slaughter plants. Estimated sensitivities of extended post-mortem meat (EPM) inspection ranged from 85.7 to 94.8% (1993-1994) and 73.8 to 93.0% (1997-1998). All estimated specificities were >93.3%. The possible association of the estimated true prevalence of CP with time (1993-1994 versus 1997-1998) was investigated with a logistic-regression model with random effects. A slight, but non-significant decrease in the odds of CP from 1994 to 1998 was found (odds ratio=0.9). In this and similar situations, one should consider conducting ongoing double-classification of samples of units followed by statistical estimation of true prevalences, sensitivities and specificities, so that decisions can be based on such estimates rather than on crude apparent prevalences.

Animals↗
PubMed2004

Is JPEG compression of videomicroscopic images compatible with telediagnosis? Comparison between diagnostic performance and pattern recognition on uncompressed TIFF images and JPEG compressed ones.

Early melanoma diagnosis is an important goal for dermatologists. Polarized light systems are increasingly employed for dermatoscopic diagnosis of melanocytic lesions. For the purpose of teledermoscopy, whose importance is increasingly growing for consultation and teaching purposes, it is of utmost importance to establish whether, after compression, polarized light images maintain their informativeness. The aim of our study was to check the effects of compression on melanocytic lesion images acquired by means of a digital videomicroscope on the identification of morphological details of the image and on diagnostic accuracy. A total of 170 50-fold-magnified pigmented skin lesion images, acquired in Tagged Image File Format (TIFF) by a digital videomicroscope, were compressed using Joint Photographic Experts Group (JPEG) algorithms (compression factor 30). Two experts in videomicroscopy evaluated both original and compressed images twice by describing single lesion features and expressing a diagnosis. Reproducibility in the assessment of dermoscopic parameters and observer performance were studied by kappa statistics and Receiver Operating Characteristic (ROC) analysis. Both intra- and interobserver reproducibility in the assessment of morphological details were higher when TIFF images were considered, indicating a better image quality. Nonetheless, there was no significant difference in the diagnostic accuracy between uncompressed images and compressed ones, although the intraobserver reproducibility in the diagnostic judgement was higher for uncompressed images. Despite loss in image details, factor 30 compressed videomicroscopic images enable a good diagnostic accuracy.

Algorithms↗
PubMed2006

Diagnostic performance of MDCT for detecting aortic valve regurgitation.

OBJECTIVE: This study evaluates whether ECG-gated 16-MDCT coronary angiography provides a reliable imaging technique for detecting aortic regurgitation (AR). SUBJECTS AND METHODS: We examined 71 patients prospectively with 16-MDCT angiography using retrospective ECG gating during the mid-to-end diastolic phase. A visible central valvular leakage area was considered as a diagnostic criterion for AR. The central valvular leakage area was quantified in patients with positive transthoracic echocardiography (TTE). We compared 16-MDCT to Doppler TTE, the accepted diagnostic standard based on semiquantitative regurgitation jet analysis (grade 0-3+ for mild, moderate, and severe). RESULTS: The overall sensitivity of 16-MDCT for the identification of patients with AR was 81%. The specificity was 91%, the negative predictive value was 70%, and the positive predictive value was 95%. Of the 71 patients, 48 had AR determined by TTE, and 16-MDCT correctly detected AR in 39 of those 48 patients. The sensitivity of 16-MDCT for the detection of patients with moderate and severe AR (grade > or = 1.5+) was 95%, and the specificity was 96% (20 of 21 patients). The sensitivity of 16-MDCT for identification of patients with mild AR (grade < or = 1+) was 70%, and the specificity was 92% (19 of 27 patients). Quantification of the central valvular leakage area was not possible in 50% of cases with AR by TTE because of valve calcifications. CONCLUSION: Sixteen-MDCT coronary angiography provides an accurate, noninvasive imaging technique to detect moderate and severe aortic regurgitation (grade > or = 1.5+). However, severe valve calcifications and mild AR limit its results.

Adult↗
PubMed2006

Influence of history of heart failure on diagnostic performance and utility of B-type natriuretic peptide testing for acute dyspnea in the emergency department.

BACKGROUND: The aim of this study was to assess the impact of a history of heart failure (HF) on emergency department (ED) B-type natriuretic peptide (BNP) testing and impact of feedback of BNP level to ED physicians. METHODS: Admission BNP was measured in 143 patients (mean age 79 +/- 10 years) presenting to the ED with dyspnea. Emergency department physicians scored probability of HF as cause of dyspnea and categorized cause of dyspnea. An independent cardiologist determined cause of dyspnea after chart review. In 83 patients, ED physicians rescored and reclassified patients after BNP measurement and evaluated test utility. RESULTS: The area under the receiver operating characteristic curve for BNP diagnosis of HF cause of dyspnea was significantly worse in patients with history of HF than those without (0.74 vs 0.94, P < .01) and in those with left ventricular ejection fraction <50% (0.64 vs 0.87, P < .05). A BNP cut point of 100 pg/mL had 100% sensitivity but only 41% specificity for diagnosing acute HF, whereas a cut point of 400 pg/mL had 87% sensitivity and 76% specificity. Emergency department physicians rated BNP useful in 64% of patients, and diagnostic uncertainty was reduced from 53% to 25% (P < .001). CONCLUSION: B-type natriuretic peptide test performance for diagnosis of dyspnea cause is significantly reduced in patients with a history of HF and must be taken into consideration in the evaluation of such patients in the ED.

Acute Disease↗
PubMed2003

Dental panoramic radiograph as a tool to detect postmenopausal women with low bone mineral density: untrained general dental practitioners' diagnostic performance.

The detection of postmenopausal women with low bone mineral density (BMD) is an important strategy to reduce the incidence of osteoporotic fracture. Recent studies suggested that incidental findings on dental panoramic radiographs may be used as a tool to detect women with low BMD. However, little is known whether this finding is sufficiently assessed by untrained general dental practitioners (GDPs). The purpose of this study was to investigate: (1) the observer agreement and (2) the diagnostic efficacy in detecting women with low BMD, when untrained GDPs assess the appearance (normal or eroded) of the mandibular inferior cortex on dental panoramic radiographs of postmenopausal women. Twenty-seven GDPs were asked to classify the appearance of the mandibular inferior cortex on dental panoramic radiographs of 100 postmenopausal women who had completed BMD assessments of the lumbar spine and of the femoral neck. Intra-and inter-observer agreements were analyzed with kappa statistics. The diagnostic efficacy (sensitivity, specificity and predictive values) was analyzed by comparing two groups classified by the mandibular inferior cortex (women with normal and women with eroded mandibular inferior cortex) with those classified by BMD (women with normal BMD and women with osteopenia or osteoporosis). The mean sensitivity and specificity were 77% and 40%, respectively, when BMD of the lumbar spine was used as standard and 75% and 39%, respectively, when BMD of the femoral neck comprised the standard. Nineteen untrained GDPs (70%) presented a moderate to almost perfect intra-observer agreement. We conclude that dental panoramic radiograph may be used in clinical dental practice to identify postmenopausal women who have undetected low BMD and should undergo further testing with bone densitometry.

Aged↗
PubMed2001

Diagnostic angiography performed by nurses.

The aim of this study was to assess the feasibility of a nurse performing diagnostic angiography. After a theoretical and practical training course on the techniques of arterial catheterization, the nurse performed diagnostic angiography under supervision on 68 patients. Patients with impalpable femoral pulses or scarred groins as well as obese patients were excluded. Successful arterial catheterization was achieved in 58 (85%) patients. Complications were limited to a severe haematoma requiring surgery in one patient and seven minor self-limiting haematomas. On this evidence, it is feasible and safe for appropriately trained nurses to perform angiography in radiology departments that have limited radiology staffing levels and no non-invasive alternations to catheter-based angiography.

Angiography↗