Combining Carotid Intima-media Thickness with Carotid Plaque on Screening for Coronary Heart Disease

2009 ◽  
Vol 16 (3) ◽  
pp. 155-159 ◽  
Author(s):  
David S Wald ◽  
Jonathan P Bestwick ◽  
Geraint Morton ◽  
Linda Drummond ◽  
Nick Jenkins ◽  
...  
Keyword(s):  
Coronary Heart Disease ◽  
False Positive ◽  
Carotid Plaque ◽  
Detection Rate ◽  
False Positive Rate ◽  
Intima Media Thickness ◽  
Carotid Imt ◽  
Percentage Points ◽  
Screening Performance ◽  
Positive Rate

Background Ultrasound-detected carotid artery intima-media thickness (IMT) and carotid plaque are possible screening tests for coronary heart disease (CHD) among asymptomatic individuals. Objective To assess the increase in screening performance of combining carotid IMT and plaque compared with each measurement alone in the identification of individuals with CHD. Methods Ultrasound examination of left and right carotid arteries was performed on 100 individuals (median age 57), 55 with a history of CHD (unstable angina or myocardial infarction) and 45 without. IMT measurements were taken from the common carotid artery and plaque was identified above, at and below the carotid bifurcation. Associations between IMT and plaque were determined using logistic regression, and screening performance was assessed from the distributions of IMT and plaque among cases and controls. Results At a false-positive rate of 5%, IMT (cut-off >0.75 mm) identified 30% (95% CI 14–58) of affected individuals. There was an increase in the detection rate of 8 percentage points (1–33%) using IMT and plaque combined compared with IMT alone. As the false-positive increased, the difference in the detection rate increased, up to a maximum of 20 percentage points (5–38%) at a false-positive rate of 20%. The comparison of IMT and plaque combined with plaque alone could only be estimated for the false-positive rate observed using plaque alone (18%); at this point the detection rate was 72% for plaque and 75% for plaque and IMT combined, an increase of 3 percentage points (0–4%). Conclusion In screening for CHD, combining carotid IMT measurement with plaque assessment is better than using either measurement alone, but the improvement in discrimination is not sufficient to make carotid ultrasound screening for CHD worthwhile.

The efficacy of combining several risk factors as a screening test

2005 ◽  
Vol 12 (4) ◽  
pp. 197-201 ◽  
Author(s):  
Nicholas J Wald ◽  
Joan K Morris ◽  
Simon Rish
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Individual Risk ◽  
Detection Rates ◽  
Screening Performance ◽  
Positive Rate ◽  
The Individual

Objective: To determine the quantitative effect on overall screening performance (detection rate for a given false-positive rate) of using several moderately strong, independent risk factors in combination as screening markers. Setting: Theoretical statistical analysis. Methods: For the purposes of this analysis, it was assumed that all risk factors were independent, had Gaussian distributions with the same standard deviation in affected and unaffected individuals and had the same screening performance. We determined the overall screening performance associated with using an increasing number of risk factors together, with each risk factor having a detection rate of 10%, 15% or 20% for a 5% false-positive rate. The overall screening performance was estimated as the detection rate for a 5% false-positive rate. Results: Combining the risk factors increased the screening performance, but the gain in detection at a constant false-positive rate was relatively modest and diminished with the addition of each risk factor. Combining three risk factors, each with a 15% detection rate for a 5% false-positive rate, yields a 28% detection rate. Combining five risk factors increases the detection rate to 39%. If the individual risk factors have a detection rate of 10% for a 5% false-positive rate, it would require combining about 15 such risk factors to achieve a comparable overall detection rate (41%). Conclusion: It is intuitively thought that combining moderately strong risk factors can substantially improve screening performance. For example, most cardiovascular risk factors that may be used in screening for ischaemic heart disease events, such as serum cholesterol and blood pressure, have a relatively modest screening performance (about 15% detection rate for a 5% false-positive rate). It would require the combination of about 15 or 20 such risk factors to achieve detection rates of about 80% for a 5% false-positive rate. This is impractical, given the risk factors so far discovered, because there are too few risk factors and their associations with disease are too weak.

scholarly journals Rapid and Automatic Detection of Micronuclei in Binucleated lymphocytes Image

2021 ◽  
Author(s):  
Xiang Shen ◽  
Ying Chen ◽  
Chaowen Li ◽  
Fucheng Yang ◽  
Zhanbo Wen ◽  
...  
Keyword(s):  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Research Work ◽  
Estimation Method ◽  
Automatic Detection ◽  
Dose Estimation ◽  
Binucleated Cell ◽  
Positive Rate ◽  
Binucleated Lymphocytes

Abstract In terms of radiation biological dose estimation, the cytokinesis block micronucleus (CBMN) assay is the internationally recognized dose estimation method. Due to the subjectivity and the time-consuming of manual detection, it cannot meet the needs of rapid standard assay of CBMN. Therefore, in this research work, we combined the convolutional neural network to design a software that can be used for rapid standard automatic detection of micronuclei in Giemsa stained binucleated lymphocytes image. The software analysis workflow is divided into four stages: cell acquisition, adhesive cell masses segmentation, cell type identification, micronucleus counting. After verification, our algorithm can quickly and effectively detect binucleated cells and micronucleus even when the cytoplasm is blurred, multiple micronucleus are attached to each other, or micronucleus is attached to the nucleus. In the test of a large number of random images, the software reached 99.4% of the manual detection in terms of the detection rate of binucleated cell, and the false positive rate of binucleated cell was 14.7%. In terms of micronucleus detection rate, the software reached 115.1% of manual detection, and its false positive rate was 26.2%. The analysis time of each picture is about 0.3s, an order of magnitude faster than conventional method.

scholarly journals Predicting first-trimester outcome of embryos with cardiac activity in women with recurrent spontaneous abortion

2020 ◽  
Vol 48 (6) ◽  
pp. 030006052091182
Author(s):  
Huixian Li ◽  
Shuang Qin ◽  
Fanfan Xiao ◽  
Yuhong Li ◽  
Yunhe Gao ◽  
...  
Keyword(s):  
Pregnant Women ◽  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Cardiac Activity ◽  
First Trimester ◽  
Clinical Indicators ◽  
Early Outcome ◽  
Heart Motion ◽  
Positive Rate

Objective This study was performed to evaluate the capability of routine clinical indicators to predict the early outcome of embryos with cardiac activity in women with recurrent spontaneous abortion (RSA). Methods A retrospective cohort study of pregnant women with a history of RSA in a Chinese tertiary hospital was performed using unadjusted and multivariable logistic regression. Results Of 789 pregnant women with RSA, 625 (79.21%) had ongoing pregnancy, whereas 164 (20.79%) developed abortion before 20 full weeks of gestational age even after embryonic heart motion was detected. The final model had an area under the curve of 0.81 (95% confidence interval, 0.78–0.84) with a sensitivity of 74.39%, a specificity of 76.00%, and a false-positive rate of 52.32% at a fixed detection rate of 90%. Conclusions The combination of multiple routine clinical indicators was valuable in predicting the early outcome of embryos with cardiac activity in viable pregnancies with RSA. However, this model might result in a high false-positive rate with a fixed detection rate of 90%; other markers must be investigated to identify first-trimester RSA once positive embryonic heart motion is established.

An evaluation of tail paint as an aid or alternative to oestrus detection

1983 ◽  
Vol 37 (2) ◽  
pp. 221-227 ◽  
Author(s):  
M. J. Ducker ◽  
Rosemary A. Haggett ◽  
W. J. Fisher ◽  
Glenys A. Bloomfield ◽  
S. V. Morant
Keyword(s):  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Critical Time ◽  
Successful Pregnancy ◽  
Service Period ◽  
Significant Difference ◽  
Positive Rate ◽  
The Mean ◽  
Paint Removal

ABSTRACTOne hundred Friesian heifers were tail-painted between 14 and 21 days after calving. Once a week the paint strip was renewed if any paint had been removed. Over the whole period of observation the ovulation detection rate by definite signs of oestrus was high (0·79), whilst the proportion of silent ovulations detected by tail paint removal was low (0·10). In addition, tail paint was not removed on 0·28 of the occasions when definite oestrus with ovulation occurred and on 0·26 of the occasions when all the paint was removed it was not associated with any reproductive event. In practice, the critical time for tail paint to be effective is during the service period. Again, tail paint identified fewer (P < 0·001) ovulations than definite signs of oestrus (0·66) and had a significantly higher false positive rate (P < 0·001). Month of calving did not affect these results but the accuracy of tail paint declined as the season progressed (P < 0·001). False positive indications were not associated with individual animal characteristics. In a second trial 43 cows were tail-painted and 43 were not. There was no significant difference in the mean number of days from calving to first insemination or successful pregnancy between the two groups. It is concluded that in these trials tail paint was not an effective or reliable aid or alternative to oestrus detection.

Jobst et al's “Detection in Life of Confirmed Alzheimer's Disease Using a Simple Measurement of Medial Temporal Lobe Atrophy by Computed Tomography”

1993 ◽  
Vol 163 (6) ◽  
pp. 809-812 ◽  
Author(s):  
Michael Philpot ◽  
Alistair Burns
Keyword(s):  
Computed Tomography ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Temporal Lobe ◽  
False Positive ◽  
Medial Temporal Lobe ◽  
Detection Rate ◽  
False Positive Rate ◽  
Minimum Width ◽  
Positive Rate

‘The medial temporal lobe of the brain is important for normal cognitive function, notably for memory, and is the region with the most extensive pathological change in Alzheimer's disease (AD). We wanted to find out if atrophy of the medial temporal lobe could be detected in life in patients in whom a diagnosis of AD was subsequently established histopathologically. The minimum width of the medial temporal lobe, measured by temporal-lobe-oriented computed tomography (CT) about one year before death, in 44 patients with a histopathological diagnosis of AD (cases) was nearly half (0.56 of the median) that in 75 controls of the same age with no clinical evidence of dementia (95% confidence interval 0.51–0.61). There was little overlap between the distributions of measurements in cases and controls. A cut-off (< 0.79 MoM) selected to yield a 5% false-positive rate gave an expected detection rate of 92%. A cut-off selected to yield a false-positive rate of 1 % (< 0.70 MoM) yielded a 79% detection rate. 20 of the 44 patients with histopathologically diagnosed AD had been scanned more than once before death, and the test (cut-off < 0.79 MoM) was positive in all 20 more than a year before and in 9/10 more than 2 years before death. In 10 subjects with dementia but with histopathology excluding AD, the mean minimum width of the medial temporal lobe was significantly greater than that in the cases with AD, but was not significantly different from that in controls. Medial temporal lobe CT is a non-invasive, rapid, simple and effective test for AD which could have immediate application firstly in improving the accuracy of prevalence and incidence studies and, secondly, for the identification of groups of high-risk patients in the evaluation of novel treatments for AD. In the future, it could be applied as a screening test.”

Screening for Diabetic Retinopathy in Primary Care: Retinal Photography Alone can Be Used Efficiently and Effectively to Exclude Those with Sight Threatening Lesions

1997 ◽  
Vol 4 (3) ◽  
pp. 174-176 ◽  
Author(s):  
P M S Evans ◽  
T S Purewal ◽  
A Hopper ◽  
H Slater ◽  
D R L Jones ◽  
...  
Keyword(s):  
Primary Care ◽  
Diabetic Retinopathy ◽  
Gold Standard ◽  
Detection Rate ◽  
False Positive Rate ◽  
Poor Quality ◽  
Background Retinopathy ◽  
Screening Performance ◽  
Positive Rate ◽  
Retinal Photography

Background— Good screening performance of retinal photography and ophthalmoscopy together in screening for diabetic retinopathy in primary care have been reported. This study reanalysed the data to evaluate the screening performance of photography alone. Methods— One thousand and ten patients screened by fundal photography and ophthalmoscopy were studied retrospectively. Fundal photographs were quality graded with poor quality pictures being excluded from the analysis. Each patient was reviewed initially by both retinal photographs and ophthalmoscopy by an ophthalmologist, the “gold standard”. Six months later the fundal photographs were reviewed and reported in a blinded manner by the ophthalmologist. Results— Two thousand and fourteen photographs were obtained, of which 162 (8%) had to be excluded because of poor quality. On review of the remaining 18S2 photographs in isolation, of 77 cases of severe retinopathy as determined by the “gold standard”, 67 had severe changes on photography—detection rate 87%. Of the 1775 cases without sight threatening retinopathy only five were judged to have sight threatening changes on photography—false positive rate 0.3%. Considering sight threatening and background retinopathy together, the detection rate was 69% (2S7 of 375) and the false positive rate 1.6% (23 of 1477). Conclusion— Good quality fundal photographs alone seem specific enough to screen for sight threatening diabetic retinopathy, but will underdetect background retinopathy.

scholarly journals The effect of correlations between screening markers on screening performance

2007 ◽  
Vol 14 (3) ◽  
pp. 151-157 ◽  
Author(s):  
J K Morris ◽  
N J Wald
Keyword(s):  
Computer Simulation ◽  
Detection Rate ◽  
Prenatal Screening ◽  
False Positive Rate ◽  
Strong Correlations ◽  
Computer Simulation Study ◽  
Opposite Pattern ◽  
Screening Performance ◽  
Positive Rate ◽  
Highly Correlated

Objectives: It is widely thought that correlations between screening markers will tend to degrade screening performance. We performed a computer simulation study to investigate the quantitative effect of correlations between two markers on screening performance, using prenatal screening for Down's syndrome as an example, although the results apply generally. Methods: Monte Carlo simulation was used to generate values of two hypothetical markers, A and B, in 1000 affected and 1000 unaffected pregnancies. The means, standard deviations and correlations of A and B were varied in five different examples. Results: If markers A and B are, on average, higher in affected than unaffected pregnancies and each marker, individually, has the same detection rate for a given false-positive rate (i.e. the same screening performance), then the screening performance of A and B together tends to decrease as A and B become more positively correlated with each other (within affected or unaffected categories) and tends to increase as A and B become more negatively correlated. If A is, on average, higher in affected pregnancies and B is, on average, lower in affected pregnancies (but again each marker has the same screening performance), the opposite pattern is observed; screening performance increases as A and B become more positively correlated and screening performance decreases as they become more negatively correlated. If A and B have unequal screening performances, modest correlations between A and B have little effect on the screening performance of A and B together, but when the correlations are strong whether positive or negative (with r values greater than about 0.45 or less than −0.45) screening performance progressively increases. Conclusion: Correlations between screening markers considered separately in affected and unaffected pregnancies can either decrease or increase screening performance. In practice, these effects are usually modest, because most screening markers are not highly correlated with each other and the effects become important only with strong correlations, whether positive or negative.

scholarly journals SISTEM PENDETEKSI POLA TAJWID AL-QUR’AN HUKUM IKHFA SYAFAWI DAN IDGHAM MIMI PADA CITRA MENGGUNAKAN METODE EUCLID DISTANCE DAN BRAY CURTIS DISTANCE

2018 ◽  
Vol 10 (2) ◽  
pp. 109
Author(s):  
Defry Hamdhana ◽  
Fadlisyah Fadlisyah ◽  
Safira Adani
Keyword(s):  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Positive Rate

Al-Qur’an adalah Kalamullah, sebagai mu’jizat, yang telah diturunkan kepada penutup para Nabi dan Rasul, Muhammad dengan perantara Jibril yang termaktub dalam mushaf-mushaf yang dinukil sampai kepada kita secara mutawatir, membacanya sebagai ibadah, yang dimulai dengan surah Al-Fatihah yang ditutup dengan surah An-Nas. Untuk membaca Al-Qur’an diperlukan pengetahuan tentang pedoman ilmu Tajwid. Dalam penelitian ini, metode Euclid Distance dan Bray Curtis Distance digunakan untuk menghitung jarak keakurtan pola Tajwid pada citra Al-Qur’an. Hasil pengujian menunjukan bahwa keakuratan sistem ini sebesar 70% hingga 90%. Persentase detection rate tersebut menunjukkan bahwa metode Euclid Distance dan Bray Curtis Distance dapat digunakan sebagai salah satu pendekatan untuk pendeteksian pola Tajwid pada citra Al-Qur’an, akan tetapi dari segi hasil Big Theta menyatakan bahwa algoritma Euclid Distance lebih efisien karena memiliki jumlah Big Theta yang lebih kecil dari Bray Curtis Distance. Sistem ini memiliki beberapa kelemahan yaitu memiliki false positive rate yang tinggi, dapat dilihat pada unjuk kerja dari sistem pendeteksi Tajwid ini, proses keakurasiannya dapat dilakukan dengan memberikan pelatihan lebih lanjut dengan tambahan data training yang lebih banyak dan lebih bervariasi, dan inputan sampel bisa berupa citra Al-Qur’an selain dari surat Al-Baqarah. Walaupun begitu, sistem deteksi Tajwid ini tidak menafikan pentingnya guru untuk membimbing dalam belajar cara baca sesuai dengan hukum-hukum Tajwid yang benar.

scholarly journals SISTEM PENDETEKSI POLA TAJWID AL-QUR’AN HUKUM MAD THABI’I (MAD ASLI) PADA CITRA MENGGUNAKAN METODE SOKAL & MICHENER

2018 ◽  
Vol 10 (2) ◽  
pp. 15
Author(s):  
Yasir Amani ◽  
Ilham Syahputra ◽  
Dian Siddiq
Keyword(s):  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Positive Rate

Al-Qur’an merupakan kalam Allah SWT yang diturunkan melalui Malaikat Jibril diberikan kepada Nabi Muhammad SAW yang dijaga kesucian dan keasliannya sampai akhir zaman dan juga sebagai sumber utama umat islam untuk menjalankan kehidupannya. Kita sebagai umat islam wajib mempelajari dan memahami apa saja isi-isi yang terkandung didalam Al-Qur’an. Dalam konteks sehari-hari banyak orang kesulitan dalam menemukan hukum tajwid di dalam Al Quran. Oleh karena itu, sistem pendeteksi tajwid diperlukan untuk membantu pengguna menemukan tajwid di dalam Al Quran. Dalam penelitian ini, Metode Sokal & Michenerdigunakan untuk menghitung jarak kemiripanpola tajwid pada citra Al Quran. Hasil pengujian menunjukan bahwa keakuratan sistem ini sebesar84.85%.Persentase detection rate tersebut menunjukkan Metode Sokal & Michener dapat digunakan sebagai salah satu pendekatan untuk pendeteksian tajwid pada citra Al Quran. Sistem ini memiliki beberapa kelemahan yaitu memiliki false positive rate, dapat dilihat pada unjuk kerja dari sistem pendeteksi tajwid ini, proses keakurasiannya dapat dilakukan dengan memberikan pelatihan lebih lanjut dengan tambahan data training yang lebih banyak dan lebih bervariasi. Walaupun begitu, sistem deteksi tajwid ini tidak menafikan pentingnya guru dalam belajar cara baca sesuai dengan hukum-hukum tajwid yang benar.

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