Effect of Noise Adaptive Wavelet Filter on Diagnostic Performance in Stroke Perfusion

2021 ◽  
Vol 11 (3) ◽  
pp. 720-729
Author(s):  
Tolga Inal ◽  
Gokce Kaan Atac ◽  
Ziya Telatar
Keyword(s):  
Diagnostic Performance ◽  
Bilateral Filter ◽  
Diagnostic Value ◽  
Intensity Profile ◽  
Filter Method ◽  
Adaptive Wavelet ◽  
Filtering Method ◽  
Profile Similarity ◽  
Value Decomposition ◽  
Contrast Bolus

Background: Computed tomography perfusion (CTP) images include more noise than routine clinic computed tomography (CT) images. Singular value decomposition based deconvolution algorithms are widely used for obtaining several functional perfusion maps. Recently block circulant singular value decomposition algorithms become popular for its superior property of immunity to contrast bolus lag. It is well known from literature that these algorithms are very sensitive to noise. There are a lot of examples of noise reduction filters in the literature as well as commercial ones. Functional maps which help physicians in the diagnostic process can be obtained with better image quality by de-noising CTP images with adaptive noise reduction filters. Objective: In this study, the effect of a noise adaptive wavelet filtering method on diagnostic performance on CTP stroke patient images is investigated. Method: Images of acute stroke patients were de-noised by this method and their diagnostic value were evaluated by visual means, peak signal-to-noise ratio and time intensity profile metrics. An observer evaluation study was carried out in order to validate quantitative image quality metrics. The results are compared with Gaussian and a bilateral filter based filtering method called TIPS (Time Intensity Profile Similarity) on same images sets to benchmark proposed method. Results: The diagnostic value of the images obtained from noise adaptive wavelet filtering method were better than Gaussian filter method and were compatible with a wellknown time intensity profile similarity bilateral filter method. Diagnostic performance of the both observers were improved compared to both Gaussian and TIPS methods. Conclusion: The noise adaptive wavelet filter method succeeded to reduce noise while preserving details contained in the contrast bolus. Its final effect on the timeintensity profiles and generated perfusion maps are compatible with the literature and showed improvements on diagnostic performance on specificity and overall accuracy when compared to other methods.

scholarly journals Diagnostic Value of Clinical Features to Distinguish Enteric Fever From Other Febrile Illnesses in Bangladesh, Nepal, and Pakistan

2020 ◽  
Vol 71 (Supplement_3) ◽  
pp. S257-S265 ◽  
Author(s):  
Kristen Aiemjoy ◽  
Dipesh Tamrakar ◽  
Shampa Saha ◽  
Shiva R Naga ◽  
Alexander T Yu ◽  
...  
Keyword(s):  
Blood Culture ◽  
Clinical Features ◽  
Diagnostic Performance ◽  
Enteric Fever ◽  
Random Effect ◽  
Clinical Signs ◽  
Febrile Illness ◽  
Diagnostic Value ◽  
Case Definition ◽  
Mixed Effect

Abstract Background Enteric fever, a bacterial infection caused by Salmonella enterica serotypes Typhi and Paratyphi A, frequently presents as a nonlocalizing febrile illness that is difficult to distinguish from other infectious causes of fever. Blood culture is not widely available in endemic settings and, even when available, results can take up to 5 days. We evaluated the diagnostic performance of clinical features, including both reported symptoms and clinical signs, of enteric fever among patients participating in the Surveillance for Enteric Fever in Asia Project (SEAP), a 3-year surveillance study in Bangladesh, Nepal, and Pakistan. Methods Outpatients presenting with ≥3 consecutive days of reported fever and inpatients with clinically suspected enteric fever from all 6 SEAP study hospitals were eligible to participate. We evaluated the diagnostic performance of select clinical features against blood culture results among outpatients using mixed-effect regression models with a random effect for study site hospital. We also compared the clinical features of S. Typhi to S. Paratyphi A among both outpatients and inpatients. Results We enrolled 20 899 outpatients, of whom 2116 (10.1%) had positive blood cultures for S. Typhi and 297 (1.4%) had positive cultures for S. Paratyphi A. The sensitivity of absence of cough was the highest among all evaluated features, at 65.5% (95% confidence interval [CI], 55.0–74.7), followed by measured fever at presentation at 59.0% (95% CI, 51.6–65.9) and being unable to complete normal activities for 3 or more days at 51.0% (95% CI, 23.8–77.6). A combined case definition of 3 or more consecutive days of reported fever and 1 or more of the following (a) either the absence of cough, (b) fever at presentation, or (c) 3 or more consecutive days of being unable to conduct usual activity--yielded a sensitivity of 94.6% (95% CI, 93.4–95.5) and specificity of 13.6% (95% CI, 9.8–17.5). Conclusions Clinical features do not accurately distinguish blood culture–confirmed enteric fever from other febrile syndromes. Rapid, affordable, and accurate diagnostics are urgently needed, particularly in settings with limited or no blood culture capacity.

scholarly journals The Diagnostic Value of Mir-133a in ST Elevation and Non-ST Elevation Myocardial Infarction: A Meta-Analysis

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 793
Author(s):  
Yehuda Wexler ◽  
Udi Nussinovitch
Keyword(s):  
Myocardial Infarction ◽  
Cardiovascular Disease ◽  
Diagnostic Performance ◽  
Characteristic Curve ◽  
Diagnostic Value ◽  
Receiver Operator Characteristic Curve ◽  
St Elevation Myocardial Infarction ◽  
Diagnostic Potential ◽  
St Elevation ◽  
The Impact

Numerous studies have reported correlations between plasma microRNA signatures and cardiovascular disease. MicroRNA-133a (Mir-133a) has been researched extensively for its diagnostic value in acute myocardial infarction (AMI). While initial results seemed promising, more recent studies cast doubt on the diagnostic utility of Mir-133a, calling its clinical prospects into question. Here, the diagnostic potential of Mir-133a was analyzed using data from multiple papers. Medline, Embase, and Web of Science were systematically searched for publications containing “Cardiovascular Disease”, “MicroRNA”, “Mir-133a” and their synonyms. Diagnostic performance was assessed using area under the summary receiver operator characteristic curve (AUC), while examining the impact of age, sex, final diagnosis, and time. Of the 753 identified publications, 9 were included in the quantitative analysis. The pooled AUC for Mir-133a was 0.73. Analyses performed separately on studies using healthy vs. symptomatic controls yielded pooled AUCs of 0.89 and 0.68, respectively. Age and sex were not found to significantly affect diagnostic performance. Our findings indicate that control characteristics and methodological inconsistencies are likely the causes of incongruent reports, and that Mir-133a may have limited use in distinguishing symptomatic patients from those suffering AMI. Lastly, we hypothesized that Mir-133a may find a new use as a risk stratification biomarker in patients with specific subsets of non-ST elevation myocardial infarction (NSTEMI).

Assessment of celiac artery compression using color-coded duplex sonography

2020 ◽  
Vol 76 (3) ◽  
pp. 413-423 ◽  
Author(s):  
Claudia Römer ◽  
Thomas Fischer ◽  
Oliver Haase ◽  
Martin Möckel ◽  
Bernd Hamm ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Peak Systolic Velocity ◽  
Rare Condition ◽  
Diagnostic Value ◽  
Celiac Artery ◽  
Breath Hold ◽  
Median Arcuate Ligament ◽  
Diagnostic Modality ◽  
Cross Sectional ◽  
Arcuate Ligament

BACKGROUND: Median arcuate ligament syndrome (MALS) is a rare condition due to compression of the celiac artery (CA) by an anatomically abnormal median arcuate ligament. With ultrasonography (US) as first-line diagnostic modality in patients with unclear abdominal pain, there is limited data on its diagnostic performance in MALS. OBJECTIVE: To investigate the value of CA peak systolic velocity (PSV) in the workup of patients with suspected MALS. METHODS: Patients with diagnosis of MALS between 2009 and 2019 were referred by Department of Visceral Surgery after clinical and gastroenterological workup. Diagnosis was confirmed by surgery or further cross-sectional imaging. B-mode US findings and PSV in the CA during various respiratory states were compared between patients with a final MALS diagnosis and patients not meeting the diagnostic criteria. RESULTS: Patients with proven MALS (n = 10) had higher median CA PSV during normal inspiratory breath-hold (239 [IQR, 159–327] vs. 138 [IQR, 116–152] cm/s; p < #x003C;< #x200A;0.001), and expiratory breath-hold (287 [IQR, 191–412] vs. 133 [IQR, 115–194] cm/s; p < #x003C;< #x200A;0.001) compared to patients without MALS (n = 26). CA PSV in both inspiratory breath-hold (AUC 0.88, 95% CI 0.77–1.00) and expiratory breath-hold (AUC 0.89, 95% CI 0.78–1.00) was of diagnostic value for confirming MALS. The best diagnostic performance (100% sensitivity, 80% specificity) was found for the combination of CA PSVexpiration + 2.4 · PSVinspiration > 550 cm/s . CONCLUSIONS: Since results on optimal cutoff values are inconsistent, a combination of CA PSVs during breathing maneuvers may help to diagnose or rule out MALS.

Adaptive Wavelet Packet-Based De-speckling of Ultrasound Images with Bilateral Filter

2013 ◽  
Vol 39 (12) ◽  
pp. 2463-2476 ◽  
Author(s):  
Sankaralingam Esakkirajan ◽  
Chinna Thambi Vimalraj ◽  
Rashad Muhammed ◽  
Ganapathi Subramanian
Keyword(s):  
Wavelet Packet ◽  
Bilateral Filter ◽  
Ultrasound Images ◽  
Adaptive Wavelet

scholarly journals Non-invasive assessment of liver fibrosis in autoimmune hepatitis: Diagnostic value of liver magnetic resonance parametric mapping including extracellular volume fraction

2020 ◽  
Author(s):  
Narine Mesropyan ◽  
Patrick Kupczyk ◽  
Leona Dold ◽  
Tobias J. Weismüller ◽  
Alois M. Sprinkart ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Volume Fraction ◽  
Extracellular Volume ◽  
Liver Stiffness ◽  
Extracellular Volume Fraction ◽  
Diagnostic Value ◽  
Parametric Mapping ◽  
Significant Fibrosis ◽  
Non Invasive ◽  
Mapping Parameters

Abstract Purpose Autoimmune hepatitis (AIH) is an immune-mediated chronic liver disease that leads to severe fibrosis and cirrhosis. The aim of this study was to determine the diagnostic value of T1 and T2 mapping as well as extracellular volume fraction (ECV) for non-invasive assessment of liver fibrosis in AIH patients. Methods In this prospective study, 27 patients (age range: 19–77 years) with AIH underwent liver MRI. T1 and T2 relaxation times as well as ECV were quantified by mapping techniques. The presence of significant fibrosis (≥ F2) was defined as magnetic resonance elastography (MRE)-based liver stiffness ≥ 3.66 kPa. MRE was used as reference standard, against which the diagnostic performance of MRI-derived mapping parameters was tested. Diagnostic performance was compared by utilizing receiver-operating characteristic (ROC) analysis. Results MRE-based liver stiffness correlated with both, hepatic native T1 (r = 0.69; P < 0.001) as well as ECV (r = 0.80; P < 0.001). For the assessment of significant fibrosis, ECV yielded a sensitivity of 85.7% (95% confidence interval (CI): 60.1–96.0%) and a specificity of 84.6% (CI 60.1–96.0%); hepatic native T1 yielded a sensitivity of 85.7% (CI 60.1–96.0%); and a specificity of 76.9% (CI 49.7–91.8%). Diagnostic performance of hepatic ECV (area under the curve (AUC): 0.885), native hepatic T1 (AUC: 0.846) for assessment of significant fibrosis was similar compared to clinical fibrosis scores (APRI (AUC: 0.852), FIB-4 (AUC: 0.758), and AAR (0.654) (P > 0.05 for each comparison)). Conclusion Quantitative mapping parameters such as T1 and ECV can identify significant fibrosis in AIH patients. Future studies are needed to explore the value of parametric mapping for the evaluation of different disease stages.

scholarly journals Improved Image Denoising Methodology using Deep CNN Bilateral Filter Compared to Additional Methods

2021 ◽  
Vol 10 (5) ◽  
pp. 191-196
Author(s):  
Pallavi Bora ◽  
Kapil Chaudhary
Keyword(s):  
Standard Deviation ◽  
Comparative Study ◽  
Image Denoising ◽  
Gaussian Noise ◽  
Bilateral Filter ◽  
Filter Method ◽  
Novel Approach ◽  
Deep Cnn ◽  
Test Result

Image Denoising techniques are widely used to remove the noise from the images. Due to the ease of the bilateral filter, it is used very often to remove the noise from the images. In this paper, a novel approach has been proposed to enhanced bilateral filter in conjunction with CNN as a booster to eliminate Gaussian noise from Grey images. Studies reveal that standard CNN using a bilateral filter is the best technique to eliminate Gaussian noise from images along with high PSNR values. This paper also performs a comparative study of the various existing techniques for image denoising with the CNN technique and the applied Bilateral filter Method as a de facto to improve the results in terms of enhanced PSNR values. ECND Net (Enhanced CNN) applied to noisy images with standard deviation σ = 15 gives PSNR values up to 32.81 In comparison to this when both bilateral filter and deep CNN applied, in conjunction produces improved PSNR values up to 34.73 along with the equivalent standard deviation. The results in this work reveal better performance in terms of PSNR as compared to other methods. The test result proves that the bilateral filter Method along with CNN can improve the quality of restored images significantly better.

scholarly journals Penapisan Derau Gaussian, Speckle dan Salt&Pepper Pada Citra Warna

2011 ◽  
Vol 5 (3) ◽  
pp. 29
Author(s):  
Ika Purwanti Ningrum ◽  
Agfianto Eko Putra ◽  
Dian Nursantika
Keyword(s):  
Image Quality ◽  
Digital Image ◽  
Color Image ◽  
Median Filter ◽  
Bilateral Filter ◽  
Filter Method ◽  
Noise Filtering ◽  
Original Image ◽  
Average Filter

Quality of digital image can decrease becouse some noises. Noise can come from lower quality of image recorder, disturb when transmission data process and weather. Noise filtering can make image better becouse will filtering that noise from the image and can improve quality of digital image. This research have aim to improve color image quality with filtering noise. Noise (Gaussian, Speckle, Salt&Pepper) will apply to original image, noise from image will filtering use Bilateral Filter method, Median Filter method and Average Filter method so can improve color image quality. To know how well this research do, we use PSNR (Peak Signal to Noise Ratio) criteria with compared original image and filtering image (image after using noise and filtering noise).This research result with noise filtering Gaussian (variance = 0.5), highest PSNR value found in the Bilateral Filter method is 27.69. Noise filtering Speckle (variance = 0.5), highest PSNR value found in the Average Filter method is 34.12. Noise filtering Salt&Pepper (variance = 0.5), highest PSNR value found in the Median Filter method is 31.27. Keywords— Bilateral Filter, image restoration, derau Gaussian, Speckle dan Salt&Pepper

scholarly journals Imaging modality for measuring the presence and extent of the labral lesions of the shoulder: a systematic review and meta-analysis

2019 ◽  
Author(s):  
Fanxiao Liu ◽  
Xiangyun Cheng ◽  
Jinlei Dong ◽  
Dongsheng Zhou ◽  
Qian Sun ◽  
...  
Keyword(s):  
Diagnostic Performance ◽  
Imaging Modality ◽  
Meta Analysis ◽  
Mr Arthrography ◽  
Diagnostic Value ◽  
Pooled Analysis ◽  
Summary Receiver Operating Characteristic ◽  
Ct Arthrography ◽  
First Choice ◽  
Bone Damage

Abstract Background: Multiple published studies quantitatively analysing the diagnostic value of MRI, MR arthrography (MRA) and CT arthrography (CTA) for labral lesions of the shoulder have had inconsistent results. The aim of this meta-analysis was to systematically compare the diagnostic performance of MRI, MRA, CTA and CT. Methods: Two databases, PubMed and EMBASE, were used to retrieve studies targeting the accuracy of MRI, MRA, CTA and CT in detecting labral lesions of the shoulder. After carefully screening and excluding studies, the studies that met the inclusion criteria were used for a pooled analysis, including calculation of sensitivity and specificity with 95% confidence intervals (CIs) and the area under the hierarchical summary receiver operating characteristic (HSROC) curves. Results: The retrieval process identified 2633 studies, out of which two reviewers screened out all but 14 studies, involving a total of 1216 patients who were deemed eligible for inclusion in the meta-analysis. The results assessing the diagnostic performance of MRI vs. MRA for detecting labral lesions showed a pooled sensitivity of 0.77 (95% CI 0.70-0.84) vs. 0.92 (95% CI 0.84-0.96), a specificity of 0.95 (95% CI 0.85-0.98) vs. 0.98 (95% CI 0.91-0.99), and an area under the HSROC curve of 3.78 (95% CI 2.73-4.83) vs. 6.01 (95% CI 4.30-7.73), respectively. Conclusion: MRA was suggested for use in patients with chronic shoulder symptoms or a pathologic abnormality. MRI is by far the first choice recommendation for the detection of acute labral lesions. CT should be a necessary supplemental imaging technique when there is highly suspected glenoid bone damage.

scholarly journals Diagnostic performance of neutrophil CD64 index in patients with sepsis in the intensive care unit

2019 ◽  
Vol 47 (9) ◽  
pp. 4304-4311 ◽  
Author(s):  
Zhenglong Ye ◽  
Hui Zou ◽  
Shangxiang Liu ◽  
Chengqing Mei ◽  
Xiaoliang Chang ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Roc Curve ◽  
Diagnostic Performance ◽  
Coronary Bypass ◽  
Diagnostic Value ◽  
Procalcitonin Level ◽  
Reactive Protein ◽  
Neutrophil Cd64 ◽  
Sensitivity Specificity

Objective This study was performed to evaluate the diagnostic value of the neutrophil CD64 index in patients with sepsis in the intensive care unit (ICU). Methods Patients with sepsis who were treated at the ICU of the authors’ institution from December 2016 to June 2018 were retrospectively reviewed. The controls comprised age- and sex-matched patients who underwent coronary bypass and had no evidence of infection. The neutrophil CD64 index, C-reactive protein (CRP) level, and procalcitonin level were compared between the two groups. The diagnostic performance of these measures, including the sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve, was examined. Results In total, 35 patients with sepsis and 27 control patients were included in the data analysis. The sensitivity of the neutrophil CD64 index, CRP level, and procalcitonin level was 83%, 74%, and 77%, respectively. The specificity was 88%, 86%, and 81%, respectively. The area under the ROC curve was 0.923 [95% confidence interval (CI), 0.856–0.989], 0.904 (95% CI, 0.832–0.976), and 0.863 (95% CI, 0.776–0.950), respectively. Conclusion The neutrophil CD64 index is a valuable biomarker for diagnosing sepsis in patients in the ICU.

P6334Daily body weight in patients with chronic heart failure: improved diagnostic value by analysing prolonged time intervals

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Gudmundsson ◽  
P Lynga ◽  
A Langius-Eklof ◽  
E Hagglund ◽  
A Hagg-Martinell ◽  
...  
Keyword(s):  
Heart Failure ◽  
Body Weight ◽  
Chronic Heart Failure ◽  
Diagnostic Performance ◽  
Moving Average ◽  
False Positive Rate ◽  
Diagnostic Value ◽  
Time Interval ◽  
Time Intervals ◽  
Positive Rate

Abstract Background Daily body weight (BW) is a mainstay in the management of patients with chronic heart failure (HF). Guidelines recommend to take action if BW increases more than 2kg within 3 days. However, the evidence behind the 2kg/3d rule is unclear and studies have shown poor diagnostic performance of this algorithm. Purpose To assess the diagnostic value of different BW thresholds and time intervals to alert for imminent HF decompensation. Methods We studied 184 patients with HF (age 71±10 yr, EF 26±11%). 43% had been hospitalized for HF during the preceding year. They were assessed by daily BW using digital scales with direct data transfer to a central data base. The mean follow-up was 286 days. To decrease day-to-day variability, BW was analysed based on a daily moving average over 3 days. We retrospectively calculated the sensitivity and false-positive rate of BW thresholds at 1.5, 2.0, 2.5, 3.0 and 3.5 kg and time intervals between 2 and 30 days. Threshold crossings occurring within 30 days prior to a hospitalization for decompensated HF were deemed a positive alert. Results The sensitivity of 2kg/3d was poor (13%). Prolonging the time interval of weight changes markedly improved sensitivity. Increasing the weight threshold decreased the false positive rate. Greatest sensitivity (60%) was achieved using a 14 day interval at a weight threshold of 1.5 kg. However, this was associated with a high rate of false alerts (3.1 per patient/year). A weight threshold of 3.5 kg resulted in excellent specificity (0.3 false alerts per patient/year), however sensitivity was low (20%, 20 day time interval). Conclusion Monitoring daily BW using a 2kg/3d algorithm is associated with poor diagnostic performance. Generally, by analyzing stable trends over time (moving average) and using prolonged time intervals, BW monitoring with digital scales can achieve a clinically meaningful diagnostic performance. This new approach to BW monitoring may improve early detection of imminent HF decompensation.

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