scholarly journals Interexaminer agreement in caries radiographic diagnosis by conventional and digital radiographs

2005 ◽  
Vol 13 (4) ◽  
pp. 329-333 ◽  
Author(s):  
Anna Sílvia Penteado Setti da Rocha ◽  
Solange Maria de Almeida ◽  
Frab Norberto Bóscolo ◽  
Francisco Haiter Neto
Keyword(s):  
Light Microscopy ◽  
False Negative ◽  
Radiographic Diagnosis ◽  
Negative Results ◽  
Digital Radiographs ◽  
False Negative Results ◽  
Conventional Film ◽  
Significant Difference ◽  
Tooth Surfaces ◽  
Sensitivity Specificity

The purpose of this research was to compare two digital storage phosphor systems and conventional film, as well as verify the interexaminer agreement in radiographic diagnosis on occlusal and proximal cavities. Two digital systems and conventional radiographic film were used to evaluate 144 tooth surfaces with and without cavities; the radiographs were analyzed and scored in a scale of 4 points. Thirteen undergraduates and an oral radiologist participated as examiners. A light microscopy analysis was accomplished in order to validate the research. The results showed that there was no significant difference between the radiographic systems, however all of them had significant differences when compared to light microscopy, except for the Digora system on the proximal surface when the radiologist was the examiner. In the interexaminer evaluation, a moderate agreement level was obtained, and a fair to moderate level was obtained between the students and the oral radiologist. Regarding the validation (sensitivity, specificity, positive predict and negative predict) the values were similar between students and the oral radiologist, except for the sensitivity value on the occlusal surface. The students had the highest number of false-positive results and the oral radiologist the highest number of false-negative results.

Effect of Muscle Activation on the Gravity Stress View in Unstable Weber B Ankle Fractures

2020 ◽  
Vol 41 (11) ◽  
pp. 1342-1346
Author(s):  
Kimberly K. Broughton ◽  
Caroline Williams ◽  
Christopher P. Miller ◽  
Kristen Stupay ◽  
John Y. Kwon
Keyword(s):  
Muscle Activation ◽  
False Negative ◽  
Ankle Fractures ◽  
Published Data ◽  
Neutral Position ◽  
Distal Fibula ◽  
Level Of Evidence ◽  
Negative Results ◽  
False Negative Results ◽  
Significant Difference

Background: In the setting of apparently isolated distal fibula fractures, the gravity stress view (GSV) is a validated method to determine mortise stability. There is currently no published data evaluating whether dynamic muscle activation can reduce an unstable mortise. If patients with instability can overcome gravity, resultant images could yield false-negative results. The goal of this investigation was to determine if patient effort can influence medial clear space (MCS) measurements in proven unstable bimalleolar-equivalent ankle fractures. Methods: Patients presenting with Weber B fibula fractures were assessed for mortise stability using the GSV. If the GSV demonstrated instability based on MCS widening >4 mm, 3 additional views were performed: GSV with an assistant maintaining the ankle in a neutral position; GSV with the patient actively dorsiflexing to neutral; and GSV with the patient actively dorsiflexing and supinating the foot. Twenty-four consecutive patients met inclusion criteria, with a mean age of 48.7 (range, 22-85) years. Fifteen patients (62.5%) were female and 9 (37.5%) were male. The laterality was evenly divided. Results: The mean MCS was 5.8 ± 2.0 6.0 ± 2.6, and 6.2 ± 2.7 mm for the manual assist, active dorsiflexion, and active supination radiograph measurement groups, respectively ( P = .434). Only 5 of 24 subjects had any measurable decrease in their MCS with active supination, with a maximum change of 1.2 mm. The remainder of the patients had an increase in MCS ranging from 0.1 to 4.0 mm. Conclusion: There was no significant difference between measurement states indicating that muscle activation is unlikely to yield a false-negative result on GSV. Mortise instability, secondary to deep deltoid injury in the presence of gravity stress, is unlikely to be actively overcome by dynamic stabilizers, supporting the validity and specificity of the GSV. Level of Evidence: Level III, prospective study.

scholarly journals Can Patient Effort Influence Sensitivity & Specificity of the Gravity Stress View? Assessing the Potential for False Negative Results

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0014
Author(s):  
Kimberly K. Broughton ◽  
Christopher P. Miller ◽  
Caroline Williams ◽  
Kristen L. Stupay ◽  
John Y. Kwon
Keyword(s):  
Muscle Activation ◽  
Stress Test ◽  
False Negative ◽  
Ankle Fractures ◽  
Measurement Tool ◽  
Neutral Position ◽  
Distal Fibula ◽  
Negative Results ◽  
False Negative Results ◽  
Significant Difference

Category: Ankle; Trauma Introduction/Purpose: In the setting of apparently isolated distal fibula fractures, the radiographic gravity stress view (GSV) has been validated as a reliable method to determine mortise stability. Based on previous studies demonstrating that plantarflexion can increase the measured medial clear space (MCS), patients are often asked to actively hold their ankle in a neutral position. However, it has not been studied whether dynamic muscle activation in the form of attempted dorsiflexion and/or supination can reduce and realign an unstable mortise. If these efforts can overcome gravity, resultant images could lead to a false negative result and missed diagnosis of instability. The goal of the present investigation is to determine if active effort by the patient can influence MCS measurements in proven unstable bimalleolar-equivalent ankle fractures. Methods: Eighteen consecutive patients with apparently isolated distal fibula fractures (Weber-B type) identified on initial nonweightbearing radiographs were assessed for mortise stability with a standard, unassisted GSV. If the radiograph demonstrated MCS widening > 4 mm, 3 additional views were performed: GSV with an assistant manually maintaining the ankle in a neutral position; GSV with the patient actively dorsiflexing the ankle to the same neutral position; and GSV with the patient actively dorsiflexing and supinating the foot to the same neutral position. All radiographs were digitally obtained and measured using a DICOM measurement tool. The MCS was measured by the senior author (JYK) who was blinded to the nature of the ankle position. Statistical analysis of the data was then conducted. Results: Of the eighteen patients who met inclusion criteria, the mean age was 48.9 years (range: 22-85, SD=18.9). Twelve patients (66%) were female and six (33%) were male. The laterality was evenly split with nine patients presenting with a right ankle injury and nine left ankles. The data was non-parametric; therefore, a Friedman’s test was utilized for analysis between the different MCS measurements per patient. There was no statistically significant difference in the measured MCS in any of the three tested scenarios, χ2(2)=4.261, p=0.119. Only 5 of 18 subjects had any measurable decrease in their MCS when asked to supinate their foot. Of these 5, the maximum reduction was 1.21mm. The remainder of patients had an increase in MCS ranging from 0.1 to 4.0mm. Conclusion: This investigation supports the notion that the gravity stress test is unlikely to yield false negative results when patients attempt to actively maintain a neutral ankle position during imaging. There was a non-significant inverse trend indicating that dynamic effort may in fact further displace the mortise as indicated by an increased MCS in several study participants, rather than reduce it. Thus, one can conclude that despite voluntary effort, patients with bimalleolar-equivalent ankle fractures are unlikely able to overcome the effect of gravity on the unstable mortise.

Three highly sensitive "bedside" serum and urine tests for pregnancy compared

1990 ◽  
Vol 36 (9) ◽  
pp. 1686-1688 ◽  
Author(s):  
H Christensen ◽  
H H Thyssen ◽  
O Schebye ◽  
A Berget
Keyword(s):  
Paired Comparison ◽  
False Negative ◽  
Diagnostic Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Negative Results ◽  
False Negative Results ◽  
Significant Difference ◽  
Comparison Of The Results ◽  
Urine And Serum

Abstract We examined three enzyme-linked immunosorbent assay (ELISA) kits for human choriogonadotropin (hCG) (pregnancy tests) for use with urine and serum samples: the Tandem Icon II hCG Urine and Tandem Icon II hCG Serum, the NovoClone Target hCG Test, and the Abbott TestPacks hCG-urine and hCG-serum. Paired comparison of the results from each kit indicated that the NovoClone Target assay showed significantly lower diagnostic sensitivity (P less than 0.05) than did the Tandem Icon II or Abbott TestPack, both for urine and for serum samples. None of the products demonstrated any significant difference (P greater than 0.05) in diagnostic specificity, but the NovoClone Target kit showed several serious false-negative results with both urine and serum. Paired testing of urine kits vs serum kits also showed no significant differences (P greater than 0.05) in diagnostic sensitivity or specificity. We found the Abbott kits to be the most convenient to use and to read.

scholarly journals Clinical Performance of Two SARS-CoV-2 Serologic Assays

2020 ◽  
Vol 66 (8) ◽  
pp. 1055-1062 ◽  
Author(s):  
Mei San Tang ◽  
Karl G Hock ◽  
Nicole M Logsdon ◽  
Jennifer E Hayes ◽  
Ann M Gronowski ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Clinical Performance ◽  
False Negative ◽  
Diagnostic Sensitivity ◽  
Diagnostic Specificity ◽  
Negative Results ◽  
False Negative Results ◽  
Recent Emergence ◽  
Sensitivity Specificity ◽  
Record Review

Abstract Background The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a rapid proliferation of serologic assays. However, little is known about their clinical performance. Here, we compared two commercial SARS-CoV-2 IgG assays. Methods 103 specimens from 48 patients with PCR-confirmed SARS-CoV-2 infections and 153 control specimens were analyzed using SARS-CoV-2 serologic assays by Abbott and EUROIMMUN (EI). Duration from symptom onset was determined by medical record review. Diagnostic sensitivity, specificity, and concordance were calculated. Results The Abbott SARS-CoV-2 assay had a diagnostic specificity of 99.4% (95% CI; 96.41–99.98%), and sensitivity of 0.0% (95% CI; 0.00–26.47%) at <3 days post symptom onset, 30.0% (95% CI; 11.89–54.28) at 3–7d, 47.8% (95% CI; 26.82–69.41) at 8–13d and 93.8% (95% CI; 82.80–98.69) at ≥14d. Diagnostic specificity on the EI assay was 94.8% (95% CI; 89.96–97.72) if borderline results were considered positive and 96.7% (95% CI; 92.54–98.93) if borderline results were considered negative. The diagnostic sensitivity was 0.0% (95% CI; 0.00–26.47%) at <3d, 25.0% (95% CI; 8.66–49.10) at 3–7d, 56.5% (95% CI; 34.49–76.81) at 3–7d and 85.4% (95% CI; 72.24–93.93) at ≥14d if borderline results were considered positive. The qualitative concordance between the assays was 0.83 (95% CI; 0.75–0.91). Conclusion The Abbott SARS-CoV-2 assay had fewer false positive and false negative results than the EI assay. However, diagnostic sensitivity was poor in both assays during the first 14 days of symptoms.

scholarly journals Imaging-Cytology Correlation of Thyroid Nodules with Initially Benign Cytology

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shin Hye Hwang ◽  
Ji Min Sung ◽  
Eun-Kyung Kim ◽  
Hee Jung Moon ◽  
Jin Young Kwak
Keyword(s):  
Thyroid Nodules ◽  
False Negative ◽  
Needle Aspiration ◽  
Malignancy Rate ◽  
Negative Results ◽  
False Negative Results ◽  
Significant Difference ◽  
Risk Of Malignancy ◽  
Us Findings

Objective. To determine the role of imaging-cytology correlation in reducing false negative results of fine-needle aspiration (FNA) at thyroid nodules.Methods. This retrospective study included 667 nodules 1 cm or larger in 649 patients diagnosed as benign at initial cytologic evaluation and that underwent follow-up ultrasound (US) or FNA following a radiologist’s opinion on concordance between imaging and cytologic results. We compared the risk of malignancy of nodules classified into subgroups according to the initial US features and imaging-cytology correlation.Results. Among included nodules, 11 nodules were proven to be malignant (1.6%) in follow-up FNA or surgery. The malignancy rate was higher in nodules with suspicious US features (11.4%) than in nodules without suspicious US features (0.5%,P<0.001). When a thyroid nodule had discordant US findings on image review after having benign FNA results, malignancy rate increased to 23.3%, significantly higher than that of nodules with suspicious US features (P<0.001). However, no significant difference was found in the risk of malignancy between the nodules without suspicious US features (0.5%) and imaging-cytology concordant nodules (0.6%,P=0.438).Conclusions. Repeat FNA can be effectively limited to patients with cytologically benign thyroid nodules showing discordance in imaging-cytology correlation after initial biopsy, which reduces unnecessary repeat aspirations.

scholarly journals Validity of protein-creatinine and protein-osmolality ratios in the estimation of massive proteinuria in children with nephrotic syndrome

2007 ◽  
Vol 47 (4) ◽  
pp. 139
Author(s):  
M. Sukmawati ◽  
K. Suarta
Keyword(s):  
Nephrotic Syndrome ◽  
Predictive Value ◽  
Diagnostic Tests ◽  
Quantitative Methods ◽  
False Negative ◽  
Creatinine Ratio ◽  
Negative Results ◽  
False Negative Results ◽  
Sensitivity Specificity ◽  
Posttest Probability

Background Children with nephrotic syndrome have massiveproteinuria, a rate of excretion equal to or greater than 40 mg/hour/m 2 body surface. The ability to quantitate massive urinaryprotein excretion is very important for both diagnostic andprognostic purposes. Quantification of proteinuria using 24-hoururine collection (Esbach) is difficult to do especially in children;moreover, many false-positive and false-negative results arereported for any semi-quantitative methods such as dipstick andsulfosalicylic acid measurement.Objective To determine the accuracy of protein-creatinine ratio(PCR) and protein-osmolality ratio (POR) in quantification ofmassive proteinuria in children with nephrotic syndrome.Methods Diagnostic tests were conducted on children withnephrotic syndrome aged 2-12 years with Esbach as a referencestandard. Sensitivity, specificity, positive predictive value (PPV),negative predictive value, (NPV), pre and posttest probabilitywere compared between PCR and POR.Results Study patients consisted of 47 children, 38 (81%) withmassive proteinuria. PCR has sensitivity of 92%, specificity of78%, PPV of 95%, NPV of 70% and posttest probability of 95%.POR has sensitivity of 76%, specificity of 78%, PPV of 94%, NPVof 44% and posttest probability of 94%.Conclusion Both PCR and POR are accurate to determine massiveproteinuria in children with nephrotic syndrome.

scholarly journals Characterization of Focal Liver Lesions using CEUS and MRI with Liver-Specific Contrast Media: Experience of a Single Radiologic Center

2017 ◽  
Vol 38 (06) ◽  
pp. 619-625 ◽  
Author(s):  
Lukas Beyer ◽  
Florian Wassermann ◽  
Benedikt Pregler ◽  
Katharina Michalik ◽  
Janine Rennert ◽  
...  
Keyword(s):  
Contrast Media ◽  
Predictive Value ◽  
False Negative ◽  
Focal Liver Lesions ◽  
Liver Lesions ◽  
Predictive Values ◽  
Negative Results ◽  
False Negative Results ◽  
Sensitivity Specificity

Abstract Aim The purpose of this study was to compare contrast-enhanced ultrasound (CEUS), magnetic resonance imaging (MRI) using liver-specific contrast agent and a combination of both for the characterization of focal liver lesions (FLL). Methods 83 patients with both benign and malignant liver lesions were examined using CEUS and MRI after the intravenous administration of liver-specific contrast media. All patients had inconclusive results from prior imaging examinations. Histopathological specimens could be obtained in 53 patients. Ultrasound was performed using a multi-frequency curved probe (1 – 6 MHz) after the injection of 1 – 2.4 ml ultrasound contrast media. The sensitivity, specificity, positive predictive value and negative predictive value of CEUS, MRI and a combination of both (CEUS + MRI) were compared. Results The sensitivity, specificity, positive and negative predictive values regarding lesion classification were 90.9 %, 70.6 %, 92.3 % and 66.6 %, respectively, for CEUS; 90.9 %, 82.4 %, 95.2 % and 70.0 %, respectively, for MRI; and 96.9 %, 70.6 %, 92.7 % and 85.7 % respectively, for CEUS + MRI. There were no statistically significant differences. 6 malignant lesions were missed using CEUS or MRI alone (false negatives). The use of both modalities combined reduced the false-negative results to 2. Conclusion CEUS and MRI with liver-specific contrast media are very reliable and of equal informative value in the characterization of focal liver lesions. The number of false-negative results can be decreased using a combination of the two methods.

scholarly journals Evaluation of the quality of functioning of artificial neural network with logic outputs in the diagnosis of diseases of hepatopancreatoduodenal zone

2017 ◽  
Vol 98 (6) ◽  
pp. 928-932 ◽  
Author(s):  
V A Lazarenko ◽  
A E Antonov
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
False Negative ◽  
Activation Function ◽  
Negative Results ◽  
False Negative Results ◽  
Artificial Neural ◽  
Sensitivity Specificity ◽  
Diagnosis Of Diseases

Aim. To develop a set of information methods to improve the quality of neural network diagnosis of diseases of hepatopancreatoduodenal zone. Methods. The study involved 385 patients with peptic ulcer, cholecystitis and pancreatitis undergoing in-patient treatment in medical organizations of the city of Kursk. For data mining internally developed software «System of Intellectual Analysis and Diagnosis of Diseases» was used which is an environment for the creation, adjustment, training and practical clinical application of an artificial neural network, such as a multilayer perceptron with an activation function - hyperbolic tangent. Results. Hyperbolic tangent (activation function) of the output layer’s neuron takes the value OUT ∈ ℝ ∧ OUT ∈ (-1; 1) which requires an interpretation. For logic network gates, for example, presence/absence of a disease, it can be performed by comparison with an arbitrarily assigned threshold yB ∈ (0; 1). In this approach, the values are interpreted as false (if y ≤-yB), undefined if y ∈ (-yB; yB), or true (if y ≥yB). Network operation control includes calculation of sensitivity, specificity, false positive and false negative results, for which the comparison of arrays of pairs of calculated and empirical values is carried out. In case of artificial neural network use for diagnosing diseases of hepatopancreatoduodenal zone, the optimal mode was achieved assigning yB≈0.3 as a threshold of the output neuron activation function. Conclusion. Assessing the quality of the ability of artificial neural network with logic outputs to diagnose hepatopancreatoduodenal zone diseases, as well as its controlled setting, is most effective by evaluation of sensitivity, specificity, frequency of false positive and false negative results at the threshold value yB≈0.3; the demonstrated sensitivity (83-94.7%) and specificity (83-97.8%) levels are comparable to the traditionally used diagnostic methods.

A Rapid Fluorescence Assay for Danofloxacin in Beef Muscle: Effect of Muscle Type on Limit of Quantitation†

2008 ◽  
Vol 71 (8) ◽  
pp. 1720-1723 ◽  
Author(s):  
MARILYN J. SCHNEIDER
Keyword(s):  
False Negative ◽  
Threshold Level ◽  
Screening Assay ◽  
Muscle Sample ◽  
Negative Results ◽  
Sample Extract ◽  
False Negative Results ◽  
Limit Of Quantitation ◽  
Significant Difference ◽  
Beef Muscle

A simple, rapid fluorescence screening assay was applied to the analysis of beef muscle for danofloxacin at the U.S. tolerance level of 200 ng/g. Muscle samples were homogenized in acetic acid–acetonitrile, the resultant mixture centrifuged, and fluorescence of the supernatants was then measured. The significant difference between the fluorescence of control muscle sample extracts and extracts of samples fortified at 200 ng/g allowed for successful discrimination between the samples. Setting a threshold level at the average 200 ng/g fortified sample extract fluorescence −3σ allowed for identification of potentially violative samples. Successful analysis of a group of blind fortified samples over a range of concentrations was accomplished in this manner, without any false-negative results. The limits of quantitation for danofloxacin, as well as enrofloxacin, using this assay were determined in three types of beef muscle (hanging tenderloin, neck, and eye round steak), as well as in serum. Significant differences in limits of quantitation were found among the three different muscle types examined, with hanging tenderloin muscle providing the lowest value. This work not only shows the potential for use of the fluorescence screening assay as an alternative to currently used microbial or antibody-based assays for the analysis of danofloxacin in beef muscle, but also suggests that assays using beef muscle may vary in performance depending on the specific muscle selected for analysis.

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