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.

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.

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 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 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.

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.

scholarly journals Diagnostic value of lung ultrasound in patients with interstitial lung disease: a retrospective study

2019 ◽  
Author(s):  
Jun-Hong Yan ◽  
Lei Pan ◽  
Yan-Bing Gao ◽  
Guang-he Cui ◽  
Yue-Heng Wang
Keyword(s):  
Retrospective Study ◽  
Interstitial Lung Disease ◽  
Lung Disease ◽  
Clinical Diagnosis ◽  
Lung Ultrasound ◽  
False Negative ◽  
Laboratory Data ◽  
Negative Results ◽  
False Negative Results ◽  
Significant Difference

Abstract Background Interstitial lung disease (ILD) is a serious threat to human health due to its difficult diagnosis and lack of effective treatment. Lung ultrasound (LUS) has recently been applied to the detection of ILD, and butthe data on its role in the diagnosis of ILD remain limited. The aim of this study was to explore the value of LUS in the diagnosis of ILD.Methods This retrospective study was carried out by reviewing the medical records of patients admitted to a respiratory ward from June 2018 to July 2019. Only patients discharged with a clinical diagnosis of ILD and underwent high-resolution computerised tomography (HRCT) and LUS within a week were selected. Basic information about the patients, laboratory data, characteristic mages of LUS scans and diagnosis results of HRCT and LUS were collected. The sensitivity of LUS and HRCT in the diagnosis of ILD was calculated, and clinical diagnosis was applied as the gold standard.Results A total of 32 patients with a clinical diagnosis of ILD were enrolled. Out of the 32 patients, 5 patients (15.63%) had false negative results in LUS, and 3 (9.38%) had false negative results in HRCT. False positive cases were not observed. All patients were diagnosed with ILD, and thus, the specificity of the examination could not be counted. With the clinical diagnosis of ILD as the gold standard, the sensitivity values of LUS and HRCT for the diagnosis of ILD were 0.84 (0.67–0.95) and 0.91 (0.75–0.98), respectively. No significant difference in sensitivity was observed between the two groups ( P =0.4795).Conclusions LUS is not inferior to HRCT in the diagnosis of ILD. Considering its safety, low cost, portability and practicability, LUS should be considered as the first-line imaging tool for patients with suspected ILD.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

Sign in / Sign up

Export Citation Format

Share Document