Pathologic Assessment of Computerized Tomography Accuracy for the Evaluation of the Laryngeal Cartilaginous Frame Work in Laryngopharyngeal Carcinomas

1989 ◽  
Vol 75 (2) ◽  
pp. 156-162 ◽  
Author(s):  
Sandro Sulfaro ◽  
Francesco Querin ◽  
Luigi Barzan ◽  
Mario Lutman ◽  
Roberto Comoretto ◽  
...  
Keyword(s):  
Computerized Tomography ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Cartilage Destruction ◽  
High False Negative Rate ◽  
Positive Rate ◽  
Pathologic Assessment ◽  
Low Sensitivity

Sixty-six whole-organ sectioned laryngopharyngectomy specimens removed for cancer during a seven-year period were uniformly examined to determine the accuracy of preoperative high resolution computerized tomography (CT) for detection of cartilaginous involvement. Our results indicate that CT has a high overall specificity (88.2%) but a low sensitivity (47.1 %); we observed a high false-negative rate (26.5%) and a fairly low false-positive rate (5.9%). Massive cartilage destruction was easily assessed by CT, whereas both small macroscopic and microscopic neoplastic foci of cartilaginous invasion were missed on CT scans. Moreover, false-positive cases were mainly due to proximity of the tumor to the cartilage. Clinical implications of these results are discussed.

scholarly journals Flow microfluorometric system for screening gynecologic cytology specimens using propidium iodide-fluorescein isothiocyanate.

1976 ◽  
Vol 24 (1) ◽  
pp. 322-331 ◽  
Author(s):  
B J Fowlkes ◽  
C J Herman ◽  
M Cassidy
Keyword(s):  
Data Analysis ◽  
Propidium Iodide ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Fluorescein Isothiocyanate ◽  
Clinical Specimens ◽  
Positive Rate ◽  
Abnormal Cells

Seventy cervical cytology specimens have been screened by a xero resolution flow analyzer-sorter using propidium iodide and fluorescein isothiocyanate as fluorochromes for nucleus and cytoplasm, respectively. This system shows a 1% sensitivity for detection of abnormal cells using only crude visual data analysis. Screening of clinical specimens was performed on the instrument with a 5.8% false negative rate and a 11.8% false positive rate by comparison with routine visual cytologic evaluation of the same samples.

High Resolution CT and Bronchography in the Assessment of Bronchiectasis

1991 ◽  
Vol 32 (6) ◽  
pp. 439-441 ◽  
Author(s):  
K. Young ◽  
F. Aspestrand ◽  
A. Kolbenstvedt
Keyword(s):  
Retrospective Study ◽  
High Resolution ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
High Resolution Ct ◽  
Negative Rate ◽  
Different Types ◽  
Positive Rate

To elucidate the reliability of CT in the assessment of bronchiectasis, a retrospective study of high resolution CT and bronchography was carried out. A segment by segment comparison of 259 segmental bronchi from 70 lobes of 27 lungs in 19 patients was performed using bronchography as standard. CT was positive in 87 of 89 segmental bronchi with bronchiectasis giving a false-negative rate of 2%. CT was negative in 169 of 170 segmental bronchi without bronchiectasis at bronchography, giving a false-positive rate of 1%. There was agreement between the two modalities in identifying the different types of bronchiectasis.

Hand Gesture Recognition using Ensembles of Radial Basis Function (RBF) Networks and Decision Trees

1997 ◽  
Vol 11 (06) ◽  
pp. 845-872 ◽  
Author(s):  
Srinivas Gutta ◽  
Ibrahim F. Imam ◽  
Harry Wechsler
Keyword(s):  
Human Computer Interaction ◽  
Decision Trees ◽  
Gesture Recognition ◽  
False Positive ◽  
Cross Validation ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Hand Gesture ◽  
Positive Rate

Hand gestures are the natural form of communication among people, yet human-computer interaction is still limited to mice movements. The use of hand gestures in the field of human-computer interaction has attracted renewed interest in the past several years. Special glove-based devices have been developed to analyze finger and hand motion and use them to manipulate and explore virtual worlds. To further enrich the naturalness of the interaction, different computer vision-based techniques have been developed. At the same time the need for more efficient systems has resulted in new gesture recognition approaches. In this paper we present an hybrid intelligent system for hand gesture recognition. The hybrid approach consists of an ensemble of connectionist networks — radial basis functions (RBF) — and inductive decision trees (AQDT). Cross Validation (CV) experimental results yield a false negative rate of 1.7% and a false positive rate of 1% while the evaluation takes place on a data base including 150 images corresponding to 15 gestures of 5 subjects. In order to assess the robustness of the system, the vocabulary of the gestures has been increased from 15 to 25 and the size of the database from 150 to 750 images corresponding now to 15 subjects. Cross Validation (CV) experimental results yield a false negative rate of 3.6% and a false positive rate of 1.8% respectively. The benefits of our hybrid architecture include (i) robustness via query by consensus as provided by ensembles of networks when facing the inherent variability of the image formation and data acquisition process, (ii) classifications made using decision trees, (iii) flexible and adaptive thresholds as opposed to ad hoc and hard thresholds and (iv) interpretability of the way classification and retrieval is eventually achieved.

scholarly journals Evaluating the usefulness of breast strain elastography for intraductal lesions

2021 ◽  
Author(s):  
Yumi Kokubu ◽  
Keiko Yamada ◽  
Masahiko Tanabe ◽  
Ayumi Izumori ◽  
Chieko Kato ◽  
...  
Keyword(s):  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Intraductal Papilloma ◽  
Breast Diseases ◽  
Strain Elastography ◽  
Negative Rate ◽  
Positive Rate ◽  
Sensitivity Specificity

Abstract Purpose Strain elastography for imaging lesion stiffness is being used as a diagnostic aid in the malignant/benign discrimination of breast diseases. While acquiring elastography in addition to B-mode images has been reported to help avoid performing unnecessary biopsies, intraductal lesions are difficult to discriminate whether they are malignant or benign using elastography. An objective evaluation of strain in lesions was performed in this study by measuring the elasticity index (E-index) and elasticity ratio (E-ratio) of lesions as semi-quantitative numerical indicators of the color distribution of strain. We examined whether ductal carcinoma in situ (DCIS) and intraductal papilloma could be distinguished using these semi-quantitative numerical indicators. Methods In this study, 170 ultrasonographically detected mass lesions in 162 cases (106 malignant lesions and 64 benign lesions)—in which tissue biopsy by core needle biopsy and vacuum-assisted biopsy, or surgically performed histopathological diagnosis, was performed—were selected as subjects from among 1978 consecutive cases (from January 2014 to December 2016) in which strain elastography images were acquired, in addition to standard B-mode breast ultrasonography, by measuring the E-index and E-ratio. Results The cut-off values for E-index and E-ratio in the malignant/benign discrimination of breast lesions were determined to be optimal values at 3.5 and 4.2, respectively, based on receiver operating characteristic (ROC) curve analysis. E-index sensitivity, specificity, accuracy, and AUC value (area under the curve) were 85%, 86%, 85%, and 0.860, respectively, while those for E-ratio were 78%, 74%, 74%, and 0.780, respectively. E-index yielded superior results in all aspects of sensitivity, specificity, accuracy, and AUC values, compared to those of E-ratio. The mean E-index values for malignant tumors and benign tumors were 4.46 and 2.63, respectively, indicating a significant difference (P < 0.001). E-index values of 24 DCIS lesions and 25 intraductal papillomas were 3.88 and 3.35, respectively, which showed a considerably close value, while the false-negative rate for DCIS was 29.2%, and the false-positive rate for intraductal papilloma was as high as 32.0%. Conclusion E-index in strain elastography yielded better results than E-ratio in the malignant/benign discrimination of breast diseases. On the other hand, E-index has a high false-negative rate and false-positive rate for intraductal lesions, a factor which should be taken into account when making ultrasound diagnoses.

scholarly journals Collective Intelligence in Fingerprint Analysis

2019 ◽  
Author(s):  
Jason Marcus Tangen ◽  
Kirsty Kent ◽  
Rachel A Searston
Keyword(s):  
Small Groups ◽  
False Positive ◽  
Collective Intelligence ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Random Errors ◽  
Fingerprint Analysis ◽  
High Stakes ◽  
Positive Rate

When a fingerprint is located at a crime scene, a human examiner is counted upon to manually compare this print to those stored in a database. Several experiments have now shown that these professional analysts are highly accurate, but not infallible, much like other fields that involve high-stakes decision making. One method to offset mistakes in these safety-critical domains is to distribute these important decisions to groups of raters who independently assess the same information. This redundancy in the system allows it to continue operating effectively even in the face of rare and random errors. Here, we extend this “wisdom of crowds” approach to fingerprint analysis by comparing the performance of individuals to crowds of professional analysts. We replicate the previous findings that individual experts greatly outperform individual novices, particularly in their false positive rate, but they do make mistakes. When we pool the decisions of small groups of experts by selecting the decision of the majority, however, their false positive rate decreases by up to 8% and their false negative rate decreases by up to 12%. Pooling the decisions of novices results in a similar drop in false negatives, but increases their false positive rate by up to 11%. Aggregating people’s judgements by selecting the majority decision performs better than selecting the decision of the most confident or the most experienced rater. Our results show that combining independent judgements from small groups of fingerprint analysts can improve their performance and prevent these mistakes from entering courts.

scholarly journals A sequence-based method for predicting extant fold switchers that undergo α-helix β-strand transitions

2021 ◽  
Author(s):  
Soumya Mishra ◽  
Loren L. Looger ◽  
Lauren L. Porter
Keyword(s):  
Secondary Structure ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Data Bank ◽  
Parent Protein ◽  
High False Negative Rate ◽  
Single Fold ◽  
Positive Rate ◽  
Α Helix

AbstractExtant fold-switching proteins remodel their secondary structures and change their functions in response to cellular stimuli, regulating biological processes and affecting human health. In spite of their biological importance, these proteins remain understudied. Few representative examples of fold switchers are available in the Protein Data Bank, and they are difficult to predict. In fact, all 96 experimentally validated examples of extant fold switchers were stumbled upon by chance. Thus, predictive methods are needed to expedite the process of discovering and characterizing more of these shapeshifting proteins. Previous approaches require a solved structure or all-atom simulations, greatly constraining their use. Here, we propose a high-throughput sequence-based method for predicting extant fold switchers that transition from α-helix in one conformation to β-strand in the other. This method leverages two previous observations: (1) α-helix <-> β-strand prediction discrepancies from JPred4 are a robust predictor of fold switching, and (2) the fold-switching regions (FSRs) of some extant fold switchers have different secondary structure propensities when expressed in isolation (isolated FSRs) than when expressed within the context of their parent protein (contextualized FSRs). Combining these two observations, we ran JPred4 on the sequences of isolated and contextualized FSRs from 14 known extant fold switchers and found α-helix <->β-strand prediction discrepancies in every case. To test the overall robustness of this finding, we randomly selected regions of proteins not expected to switch folds (single-fold proteins) and found significantly fewer α-helix <-> β-strand prediction discrepancies (p < 4.2*10−20, Kolmogorov-Smirnov test). Combining these discrepancies with the overall percentage of predicted secondary structure, we developed a classifier that often robustly identifies extant fold switchers (Matthews Correlation Coefficient of 0.70). Although this classifier had a high false negative rate (6/14), its false positive rate was very low (1/211), suggesting that it can be used to predict a subset of extant fold switchers from billions of available genomic sequences.

scholarly journals Evaluation of the Sensitivity and Specificity of Two Diagnostic Tests for Antibodies to Pseudorabies Virus Glycoprotein X

1992 ◽  
Vol 4 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Ronald M. Weigel ◽  
William F. Hall ◽  
Gail Scherba ◽  
Arthur M. Siegel ◽  
Edwin C. Hahn ◽  
...  
Keyword(s):  
False Positive ◽  
Pseudorabies Virus ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
T Test ◽  
Serum Samples ◽  
Negative Rate ◽  
Positive Rate ◽  
The Cost

The diagnostic performance of 2 enzyme-linked immunosorbent assays (gX-T, gX-H) for antibodies to pseudorabies virus (PRV) glycoprotein X (gX) were evaluated using 311 serum samples from a nonvaccinated quarantined herd. When the standardized virus neutralization (VN) test, which uses the Shope strain (VN Shope), was used as the comparative diagnostic standard, the gX-T test had a 7% false-negative rate and a 52% false-positive rate, and the gX-H test had a 19% false-negative rate and a 19% false-positive rate. When the VN test with a Bartha recombinant strain (VN Bartha gIIIKa) was used as the diagnostic standard, the gX-T test had a 9% false-negative rate and a 26% false-positive rate, and the gX-H test had a 24% false-negative rate and a 11% false-positive rate. Thus, the gX-T test was more sensitive and the gX-H test was more specific. Additional diagnostic tests on 79 serum samples from a noninfected herd did not produce false positives for the gX-H test, but there was an 8% false-positive rate for the gX-T test. Previous studies from our laboratory have demonstrated that VN Bartha gIIIKa has higher sensitivity than VN Shope, without losing specificity, and thus is a better comparative diagnostic standard. When adding a suspect range to the gX-T test, using the same criteria as the suspect range for the gX-H test, the false-positive rate of the gX-T test was reduced to 5% when evaluated versus VN Bartha gIIIKa in the infected herd and to 1% for the PRV-negative herd. However, 18% of the positive samples were classified as suspect (vs. 8% for the gX-H test). In PRV eradication programs, the cost of false negatives is greater than the cost of false positives; thus, the gX-T diagnostic used in this study is of greater diagnostic value.

Stepwise strategies in analysing haematuria and leukocyturia in screening

2006 ◽  
Vol 44 (4) ◽  
Author(s):  
Josiane Steinmetz ◽  
Joseph Henny ◽  
René Gueguen
Keyword(s):  
Microscopic Examination ◽  
Predictive Value ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Microscopic Analysis ◽  
Test Strip ◽  
Negative Rate ◽  
Positive Rate

AbstractThe aim of the present work was to compare in a supposed healthy population of 680 subjects several algorithms for positive selection of urine samples requiring microscopic examination for erythrocytes and leukocytes after screening by automated test-strip measurement and particle counting on a Sysmex UF-50™ flow cytometer. Four strategies have been formulated and the sensitivity, specificity, positive predictive value, negative predictive value, false positive rate, false negative rate, and microscopic review rate were measured. The strategy combining test strip analysis and automated counting on all samples, followed by microscopic examination of only discordant samples gave the best results. When the two methods of haematuria screening were in agreement (91% of samples), the false negative rate for microscopy was 1.1%, with a false positive rate of 0.8%, sensitivity of 66% and specificity of 99%, and the results are acceptable without any other examination. When the two methods of haematuria screening were discrepant, visual microscopic analysis was necessary to obtain definitive results. For leukocyturia screening, 80% of results were in agreement by test strip and automatic sediment urinalysis, with only ten results considered as false negatives (1.8%) and four as false positives (0.7%). Agreement was good and the other criteria were good (sensitivity 79%, specificity 99%). On conflicting samples, there was no agreement between methods and microscopic analysis was essential. The benefit of such an algorithm would be optimisation of the workflow without any loss of sensitivity and specificity at the expense of a two-fold increase in cost.

scholarly journals Development of USI-Kit for Evaluation of Iodine Content in Iodized Salt

2020 ◽  
Vol 17 (10) ◽  
pp. 1149-1156
Author(s):  
Sakaewan OUNJAIJEAN ◽  
Kongsak BOONYAPRANAI ◽  
Kanokwan KULPRACHAKARN ◽  
Kittipan RERKASEM
Keyword(s):  
Spectrophotometric Method ◽  
False Positive ◽  
False Positive Rate ◽  
False Negative ◽  
False Negative Rate ◽  
Iodine Content ◽  
Kappa Coefficient ◽  
Test Kit ◽  
Positive Rate ◽  
Sensitivity Specificity

Iodine deficiency has been considered as a serious public health problem for the past decades. Universal salt iodization program is introduced and implemented to address such problem. To encourage this program in an effective and sustainable way, it is essential to regularly monitor whether salt is adequately iodized at various points along the supply chain. The traditional iodometric titration method has problems related to accessibility, cost, and time. Colorimetric test kits have been used extensively to measure coverage of iodized salt in household surveys due to its expediency and affordability. In Thailand, “I-KIT” is the most widely used. The visualization of intensive color, however, is inconvenient for untrained-user in determining the adequacy of iodine content. Thus, an improvement to make testing more precise and affordable is still required. In this respect, a new test kit namely USI-Kit was developed to assess iodine quality and semi-quantity in edible salt. The kit was tested to evaluate its performance, by comparing the result with the I-KIT and with the spectrophotometric method. Compared with I-Kit, the USI-Kit exerted the relative accuracy, sensitivity, specificity, false positive rate, false negative rate and Kappa coefficient value of 74.0, 76.3, 72.6, 27.4, 23.7 and 0.47, respectively. Compared to the spectrophotometric method, USI-Kit exerted the relative accuracy, sensitivity, specificity, false positive rate, false negative rate and Kappa coefficient value of 85.4, 80.1, 89.3, 10.7, 19.9 and 0.70, respectively. The finding suggested that a newly developed iodine test kit holds promise to be used in field inspection of iodine content in salt.

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