scholarly journals Diagnostic Value of CT Angiography Combined with High-Resolution Magnetic Resonance Angiography in Vascular Lesions in Acute Stroke

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Mingyang Zou ◽  
Junjie Liao ◽  
Yurong Zeng ◽  
Qianwen Guan ◽  
Bowen Lan
Keyword(s):  
Magnetic Resonance ◽  
High Resolution ◽  
Magnetic Resonance Angiography ◽  
Ct Angiography ◽  
False Positive ◽  
False Positive Rate ◽  
Detection Sensitivity ◽  
Diagnosis And Treatment ◽  
High Morbidity ◽  
Positive Rate

Cerebrovascular disease is increasing rapidly because of its high morbidity and high mortality, which is a serious threat to human health. For the early diagnosis and treatment of diseases, the CT vascular noise combined with high-resolution magnetic resonance angiography in acute cerebral apoplexy vascular disease is adopted. 150 patients with ischemic stroke were selected, which were admitted to the Department of Radiology, Huizhou Central People’s Hospital, from January 2020 to December 2020. All patients accepted digital subtraction angiography (DSA), magnetic resonance angiography (MRA), and CT angiography (CTA) examination. Results. There were 76 cases of aneurysm in DSA examination, accounting for 46%; 69 cases with pulsating stenosis, accounting for 50.67%; and 5 cases of moyamoya disease, accounting for 3.33%. The number and proportion of cases of the above diseases in MRA examination were (75, 69, 71; 53.33%, 45.67%, 4%), and those in CTA examination were (71, 76, 3, 47.33%, 50.67%, 2%). Relative to the DSA gold standard, the sensitivity, specificity, and false positive rate of MRA were 81.51%, 95.19%, and 2.1, respectively, and those of CTA were 95.78%, 79.17%, and 11.0, respectively. The number of cases and accuracy of detection of cerebral aneurysms by MRA were (75, 96.57%), and those by CTA were (71, 91.2%), which was not statistically considerable, P > 0.05 . For the number of cases and the detection accuracy of cerebrovascular malformations, MRA was (38, 92.68%) and CTA was (37, 90.24%), which was not statistically considerable, P > 0.05 . Conclusion. The detection sensitivity and accuracy of MRA were better than those of CTA, while specific CTA was superior to MRA. The differences between the two detections were substantial ( P < 0.05 ), while the sensitivity and false positive rate were not remarkably different ( P > 0.05 ). Therefore, the combination of the two detections was of great significance to the diagnosis and treatment of stroke and other vascular diseases.

The Utility of MRI With Multiacquisition Variable-Resonance Image Combination (MAVRIC) in Diagnosing Deep Total Hip Arthroplasty Infection

2021 ◽  
pp. 155633162110092
Author(s):  
Ashley E. Levack ◽  
Chelsea Koch ◽  
Harold G. Moore ◽  
Michael B. Cross
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
False Positive ◽  
False Positive Rate ◽  
Positive Finding ◽  
Resonance Imaging ◽  
Total Hip ◽  
Positive Rate

Background: The 2010 American Academy of Orthopaedic Surgeons Clinical Practice Guidelines report insufficient evidence to address the diagnostic efficacy of magnetic resonance imaging (MRI) for periprosthetic joint infection (PJI). Questions/Purposes: The purpose of this study was to determine the utility of MRI with multiacquisition variable-resonance image combination (MAVRIC) metal artifact suppression techniques in diagnosing PJI in the setting of total hip arthroplasty (THA). Methods: Multiacquisition variable-resonance image combination MRIs obtained of THAs between November 2012 and November 2016 were queried. Radiology reports were classified as positive (suspicious for infection), negative (no features of infection), or inconclusive (infection cannot be excluded or correlation with aspiration suggested if clinically concerned). Chart review identified cases of deep PJI according to the modified Musculoskeletal Infection Society criteria. Results: Of 2156 MRIs of THAs included, MRI was concerning for infection in 1.8% (n = 39), inconclusive in 1.2% (n = 26), and negative in 97.0% (n = 2091). Deep PJI was identified in 53 (2.5%) patients, 30 of whom (56.6%) had conclusively positive finding on MRI (false-negative rate: 43.4%, sensitivity: 56.6%). Of 2103 aseptic THAs, only 9 (0.4%) MRIs were read as suspicious for infection (false-positive rate: 0.4%; specificity: 99.6%). Conclusion: Magnetic resonance imaging with MAVRIC is a highly specific test for PJI with a low false-positive rate. This indicates that when clinicians are provided with an MRI that unexpectedly suggests infection, a formal evaluation for infection is indicated. In patients with otherwise equivocal diagnostic findings, MRI may help confirm, but not refute, a diagnosis of PJI. Prospective study with more experienced image reviewers may further support the use of MRI in PJI.

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.

scholarly journals Simultaneous multi-cancer detection and tissue of origin (TOO) localization using targeted bisulfite sequencing of plasma cell-free DNA (cfDNA).

2019 ◽  
Vol 5 (suppl) ◽  
pp. 44-44 ◽  
Author(s):  
Geoffrey R. Oxnard ◽  
Eric A. Klein ◽  
Michael Seiden ◽  
Earl Hubbell ◽  
Oliver Venn ◽  
...  
Keyword(s):  
Cancer Detection ◽  
False Positive ◽  
Bisulfite Sequencing ◽  
High Efficiency ◽  
False Positive Rate ◽  
Detection Sensitivity ◽  
Whole Genome ◽  
Positive Rate ◽  
Cancer Types ◽  
Tissue Of Origin

44 Background: A noninvasive cfDNA blood test detecting multiple cancers at earlier stages could decrease cancer mortality. In earlier discovery work, whole-genome bisulfite sequencing outperformed whole-genome and targeted sequencing approaches for multi-cancer detection across stages at high specificity. Here, multi-cancer detection and TOO localization using bisulfite sequencing of plasma cfDNA to identify methylomic signatures was evaluated in preparation for clinical validation, utility, and implementation studies. Methods: 2301 analyzable participants (1422 cancer [ > 20 tumor types, all stages], 879 non-cancer) were included in this prespecified substudy from the Circulating Cell-free Genome Atlas (CCGA) (NCT02889978) study - a prospective, multi-center, observational, case-control study with longitudinal follow-up. Plasma cfDNA was subjected to a targeted methylation sequencing assay using high-efficiency methylation chemistry to enrich for methylation targets, and a machine learning classifier determined cancer status and tissue of origin (TOO). Observed methylation fragments characteristic of cancer and TOO were combined across targeted regions and assigned a relative probability of cancer and of a specific TOO. Results: Performance is reported at 99% specificity (ie, a combined false positive rate across all cancer types of 1%), a level required for population-level screening. Across cancer types, sensitivity ranged from 59 to 86%. Combined cancer detection (sensitivity [95% CI]) was 34% (27-43%) in stage I (n = 151), 77% (70-83%) in stage II (n = 171), 84% (79-89%) in stage III (n = 204), and 92% (88-95%) in stage IV (n = 281). TOO was provided for 94% of all cancers detected; of these, TOO was correct in > 90% of cases. Conclusions: Detection of multiple deadly cancers across stages using methylation signatures in plasma cfDNA was achieved with a single, fixed, low false positive rate, and simultaneously provided accurate TOO localization. This targeted methylation assay is undergoing validation in preparation for prospective clinical investigation as a cancer detection diagnostic. Clinical trial information: NCT02889978.

Improving diagnosis of acute appendicitis with atypical findings by Tc-99m HMPAO leukocyte scan

2002 ◽  
Vol 41 (01) ◽  
pp. 37-41 ◽  
Author(s):  
S. Shung-Shung ◽  
S. Yu-Chien ◽  
Y. Mei-Due ◽  
W. Hwei-Chung ◽  
A. Kao
Keyword(s):  
Acute Appendicitis ◽  
False Positive ◽  
False Positive Rate ◽  
Accurate Method ◽  
Clinical Findings ◽  
Pathological Findings ◽  
Lower Quadrant ◽  
Predictive Values ◽  
Positive Rate

Summary Aim: Even with careful observation, the overall false-positive rate of laparotomy remains 10-15% when acute appendicitis was suspected. Therefore, the clinical efficacy of Tc-99m HMPAO labeled leukocyte (TC-WBC) scan for the diagnosis of acute appendicitis in patients presenting with atypical clinical findings is assessed. Patients and Methods: Eighty patients presenting with acute abdominal pain and possible acute appendicitis but atypical findings were included in this study. After intravenous injection of TC-WBC, serial anterior abdominal/pelvic images at 30, 60, 120 and 240 min with 800k counts were obtained with a gamma camera. Any abnormal localization of radioactivity in the right lower quadrant of the abdomen, equal to or greater than bone marrow activity, was considered as a positive scan. Results: 36 out of 49 patients showing positive TC-WBC scans received appendectomy. They all proved to have positive pathological findings. Five positive TC-WBC were not related to acute appendicitis, because of other pathological lesions. Eight patients were not operated and clinical follow-up after one month revealed no acute abdominal condition. Three of 31 patients with negative TC-WBC scans received appendectomy. They also presented positive pathological findings. The remaining 28 patients did not receive operations and revealed no evidence of appendicitis after at least one month of follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values for TC-WBC scan to diagnose acute appendicitis were 92, 78, 86, 82, and 90%, respectively. Conclusion: TC-WBC scan provides a rapid and highly accurate method for the diagnosis of acute appendicitis in patients with equivocal clinical examination. It proved useful in reducing the false-positive rate of laparotomy and shortens the time necessary for clinical observation.

Predicting Fetal Chromosome Anomalies in the First Trimester Using Pregnancy Associated Plasma Protein-A: A Comparison of Statistical Methods

1993 ◽  
Vol 32 (02) ◽  
pp. 175-179 ◽  
Author(s):  
B. Brambati ◽  
T. Chard ◽  
J. G. Grudzinskas ◽  
M. C. M. Macintosh
Keyword(s):  
Logistic Regression ◽  
General Population ◽  
Likelihood Ratio ◽  
False Positive ◽  
False Positive Rate ◽  
Ratio Method ◽  
Detection Rates ◽  
Gaussian Distributions ◽  
Positive Rate ◽  
Likelihood Ratio Method

Abstract:The analysis of the clinical efficiency of a biochemical parameter in the prediction of chromosome anomalies is described, using a database of 475 cases including 30 abnormalities. A comparison was made of two different approaches to the statistical analysis: the use of Gaussian frequency distributions and likelihood ratios, and logistic regression. Both methods computed that for a 5% false-positive rate approximately 60% of anomalies are detected on the basis of maternal age and serum PAPP-A. The logistic regression analysis is appropriate where the outcome variable (chromosome anomaly) is binary and the detection rates refer to the original data only. The likelihood ratio method is used to predict the outcome in the general population. The latter method depends on the data or some transformation of the data fitting a known frequency distribution (Gaussian in this case). The precision of the predicted detection rates is limited by the small sample of abnormals (30 cases). Varying the means and standard deviations (to the limits of their 95% confidence intervals) of the fitted log Gaussian distributions resulted in a detection rate varying between 42% and 79% for a 5% false-positive rate. Thus, although the likelihood ratio method is potentially the better method in determining the usefulness of a test in the general population, larger numbers of abnormal cases are required to stabilise the means and standard deviations of the fitted log Gaussian distributions.

Identification of and Correction for Publication Bias: Comment

2019 ◽  
Author(s):  
Amanda Kvarven ◽  
Eirik Strømland ◽  
Magnus Johannesson
Keyword(s):  
Publication Bias ◽  
False Positive ◽  
Large Scale ◽  
Meta Analysis ◽  
False Positive Rate ◽  
Effect Sizes ◽  
Replication Studies ◽  
Moderate Reduction ◽  
Positive Rate ◽  
Meta Analyses

Andrews &amp; Kasy (2019) propose an approach for adjusting effect sizes in meta-analysis for publication bias. We use the Andrews-Kasy estimator to adjust the result of 15 meta-analyses and compare the adjusted results to 15 large-scale multiple labs replication studies estimating the same effects. The pre-registered replications provide precisely estimated effect sizes, which do not suffer from publication bias. The Andrews-Kasy approach leads to a moderate reduction of the inflated effect sizes in the meta-analyses. However, the approach still overestimates effect sizes by a factor of about two or more and has an estimated false positive rate of between 57% and 100%.

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