scholarly journals Comparison of phase-resolved functional lung (PREFUL) MRI derived perfusion and ventilation parameters at 1.5T and 3T in healthy volunteers

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244638
Author(s):  
Julian Glandorf ◽  
Filip Klimeš ◽  
Andreas Voskrebenzev ◽  
Marcel Gutberlet ◽  
Lea Behrendt ◽  
...  
Keyword(s):  
Free Breathing ◽  
Power Calculation ◽  
Data Sets ◽  
Maximum Period ◽  
The Mean ◽  
Mean Differences ◽  
Sequence Parameters ◽  
Lung Mri ◽  
Skewness And Kurtosis ◽  
Field Strengths

Purpose The purpose of this study is to evaluate the influence of different field strengths on perfusion and ventilation parameters, SNR and CNR derived by PREFUL MRI using predefined sequence parameters. Methods Data sets of free breathing 2d FLASH lung MRI were acquired from 15 healthy subjects at 1.5T and 3T (Magnetom Avanto and Skyra, Siemens Healthcare, Erlangen, Germany) with a maximum period of 3 days in between. The processed functional parameters regional ventilation (RVent), perfusion (Q), quantified perfusion (QQuant), perfusion defect percentage (QDP), ventilation defect percentage (VDP) and ventilation-perfusion match (VQM) were compared for systematic differences. Signal- and contrast-to-noise ratio (SNR and CNR) of both acquisitions were analyzed. Results RVent, Q, VDP, SNR and CNR presented no significant differences between 1.5T and 3T. QQuant (1.5T vs. 3T, P = 0.04), and QDP (1.5T vs. 3T, P≤0.01) decreased significantly at 3T. Consequently, VQM increased significantly (1.5T vs. 3T, P≤0.01). Skewness and kurtosis of the Q-values increased significantly at 3T (P≤0.01). The mean Sørensen-Dice coefficients between both series were 0.91 for QDP and 0.94 for VDP. The Bland-Altman analysis of both series showed mean differences of 4.29% for QDP, 1.23% for VDP and -5.15% for VQM. Using the above-mentioned parameters for three-day repeatability at two different scanners and field strengths, the retrospective power calculation showed, that a sample size of 15 can detect differences of 3.7% for QDP, of 2.9% for VDP and differences of 2.6% for VQM. Conclusion Significant differences in QDP may be related to field inhomogeneities, which is expressed by increasing skewness and kurtosis at 3T. QQuant reveals only poor reproducibility between 1.5T and 3T. RVent, Q, VDP, SNR and CNR were not altered significantly at the used sequence parameters. Healthy participants with minimal defects present high spatial agreement of QDP and VDP.

scholarly journals Soft Tissue Images from Cephalograms Compared With Those from a 3D Surface Acquisition System

2010 ◽  
Vol 80 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Angela K. Incrapera ◽  
Chung How Kau ◽  
Jeryl D. English ◽  
Kathleen McGrory ◽  
David M. Sarver
Keyword(s):  
Soft Tissue ◽  
3D Imaging ◽  
Data Sets ◽  
Image Capture ◽  
3D Images ◽  
Mathematical Algorithm ◽  
Final Sample ◽  
The Mean ◽  
Mean Differences ◽  
Best Fit

Abstract Objective: To assess whether 2D cephalometrics is comparable with 3D imaging devices and whether 3D technology could replace traditional 2D image capture in posttreatment evaluation. Materials and Methods: The study is a prospective evaluation of superimposition techniques obtained from a cohort of 40 patients who underwent orthognathic surgery in a private practice environment. Surgical records were obtained from lateral cephalometric radiographs taken by a Kodak 8000C machine, and the 3D images were obtained from the 3dMD stereo photogrammetric camera capture system. Pre- and postlateral cephalometric records were superimposed on the cranial base (SN line) while pre- and post-3D surgical records were superimposed on the regional best-fit method. A mathematical algorithm, or best-fit calculation, was carried out on the selected surfaces. Each set of superimposed records was analyzed, and five soft tissue landmarks were plotted. The differences between the five surface points were analyzed for each set of records. Results: The final sample consisted of 34 subjects with full records. A total of 680 surface landmarks were plotted and analyzed. The mean differences of the soft tissue landmarks were analyzed for each pair of data sets and were found to range between 1.06 and 8.07 mm and 1.26 and 7.34 mm for lateral cephalometric and 3D readings, respectively. Paired t-tests were carried out using the SPSS 15.0 software, and they showed that the results were not statistically significant between the superimposition techniques on the image capture systems (P > .05). Conclusions: The types of superimposition techniques used in the imaging modalities studied were comparable with one another.

scholarly journals Blood Oxygenation Level Dependent Magnetic Resonance Imaging (MRI), Dynamic Contrast Enhanced MRI and Diffusion Weighted MRI for Benign and Malignant Breast Cancer Discrimination: A Preliminary Experience

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2421
Author(s):  
Roberta Fusco ◽  
Vincenza Granata ◽  
Mauro Mattace Raso ◽  
Paolo Vallone ◽  
Alessandro Pasquale De Rosa ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Univariate Analysis ◽  
Mean Value ◽  
Blood Oxygenation ◽  
Breast Lesions ◽  
Dce Mri ◽  
Malignant Lesions ◽  
The Mean ◽  
And Diffusion ◽  
Skewness And Kurtosis

Purpose. To combine blood oxygenation level dependent magnetic resonance imaging (BOLD-MRI), dynamic contrast enhanced MRI (DCE-MRI), and diffusion weighted MRI (DW-MRI) in differentiation of benign and malignant breast lesions. Methods. Thirty-seven breast lesions (11 benign and 21 malignant lesions) pathologically proven were included in this retrospective preliminary study. Pharmaco-kinetic parameters including Ktrans, kep, ve, and vp were extracted by DCE-MRI; BOLD parameters were estimated by basal signal S0 and the relaxation rate R2*; and diffusion and perfusion parameters were derived by DW-MRI (pseudo-diffusion coefficient (Dp), perfusion fraction (fp), and tissue diffusivity (Dt)). The correlation coefficient, Wilcoxon-Mann-Whitney U-test, and receiver operating characteristic (ROC) analysis were calculated and area under the ROC curve (AUC) was obtained. Moreover, pattern recognition approaches (linear discrimination analysis and decision tree) with balancing technique and leave one out cross validation approach were considered. Results. R2* and D had a significant negative correlation (−0.57). The mean value, standard deviation, Skewness and Kurtosis values of R2* did not show a statistical significance between benign and malignant lesions (p > 0.05) confirmed by the ‘poor’ diagnostic value of ROC analysis. For DW-MRI derived parameters, the univariate analysis, standard deviation of D, Skewness and Kurtosis values of D* had a significant result to discriminate benign and malignant lesions and the best result at the univariate analysis in the discrimination of benign and malignant lesions was obtained by the Skewness of D* with an AUC of 82.9% (p-value = 0.02). Significant results for the mean value of Ktrans, mean value, standard deviation value and Skewness of kep, mean value, Skewness and Kurtosis of ve were obtained and the best AUC among DCE-MRI extracted parameters was reached by the mean value of kep and was equal to 80.0%. The best diagnostic performance in the discrimination of benign and malignant lesions was obtained at the multivariate analysis considering the DCE-MRI parameters alone with an AUC = 0.91 when the balancing technique was considered. Conclusions. Our results suggest that the combined use of DCE-MRI, DW-MRI and/or BOLD-MRI does not provide a dramatic improvement compared to the use of DCE-MRI features alone, in the classification of breast lesions. However, an interesting result was the negative correlation between R2* and D.

The Age of Nonsynonymous and Synonymous Mutations in Animal mtDNA and Implications for the Mildly Deleterious Theory

Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 497-506 ◽  
Author(s):  
Rasmus Nielsen ◽  
Daniel M Weinreich
Keyword(s):  
Dna Sequences ◽  
Purifying Selection ◽  
Data Sets ◽  
Deleterious Mutations ◽  
Synonymous Mutations ◽  
Weak Evidence ◽  
Mitochondrial Data ◽  
The Mean ◽  
Excess Number ◽  
Neutral Mutations

Abstract McDonald/Kreitman tests performed on animal mtDNA consistently reveal significant deviations from strict neutrality in the direction of an excess number of polymorphic nonsynonymous sites, which is consistent with purifying selection acting on nonsynonymous sites. We show that under models of recurrent neutral and deleterious mutations, the mean age of segregating neutral mutations is greater than the mean age of segregating selected mutations, even in the absence of recombination. We develop a test of the hypothesis that the mean age of segregating synonymous mutations equals the mean age of segregating nonsynonymous mutations in a sample of DNA sequences. The power of this age-of-mutation test and the power of the McDonald/Kreitman test are explored by computer simulations. We apply the new test to 25 previously published mitochondrial data sets and find weak evidence for selection against nonsynonymous mutations.

scholarly journals Effectiveness of Home-Based Occupational Therapy on COPM Performance and Satisfaction Scores in Patients with COPD

2020 ◽  
pp. 000841742097112
Author(s):  
Eleonore H. Koolen ◽  
Martijn A. Spruit ◽  
Marianne de Man ◽  
Jeanine C. Antons ◽  
Elieke Nijhuis ◽  
...  
Keyword(s):  
Occupational Therapy ◽  
Integrated Management ◽  
Performance Measure ◽  
Occupational Performance ◽  
Post Intervention ◽  
Canadian Occupational Performance Measure ◽  
Home Based ◽  
Copd Patients ◽  
The Mean ◽  
Mean Differences

Background. Occupational therapy (OT) may be an important intervention in patients with COPD, but studies show conflicting results. Purpose. To evaluate the effectiveness of home-based monodisciplinary OT in COPD patients Method. We conducted an observational clinical study. Main outcomes were the mean differences in the Canadian Occupational Performance Measure (COPM) performance and satisfaction scores, pre and post intervention. Findings. Pre- and postintervention data were obtained from 41 patients. Statistically significant increases were observed in COPM performance (5.0 ± 1.1 versus 6.9 ± 0.9; P<0.001) and satisfaction (4.6 ± 1.3 versus 6.9 ± 1.0; P<0.001). The most frequently reported occupational performance problems were found in the domains of productivity (47%) and mobility (40%), fewer in self-care (10%) and the least in leisure (3%). Implications. Home-based monodisciplinary OT can contribute significantly to the improvement of daily functioning of patients with COPD. OT should therefore be considered more often as part of the integrated management of these patients.

scholarly journals Does Every Calculation Formula Fit for All Types of Intraocular Lenses? Optimization of Constants for Tecnis ZA9003 and ZCB00 Is Necessary

Medicina ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 319
Author(s):  
Ivajlo Popov ◽  
Veronika Popova ◽  
Juraj Sekac ◽  
Vladimir Krasnik
Keyword(s):  
Prediction Error ◽  
Poor Performance ◽  
Intraocular Lenses ◽  
Power Calculation ◽  
Universal Formula ◽  
Aspheric Iol ◽  
Different Types ◽  
The Mean ◽  
Clinically Significant ◽  
Mean Prediction Error

Background and Objectives: To evaluate the performance of intraocular lenses (IOLs) using power calculation formulas on different types of IOL. Materials and Methods: 120 eyes and four IOL types (BioLine Yellow Accurate Aspheric IOL (i-Medical), TECNIS ZCB00, TECNIS ZA9003 (Johnson & Johnson) (3-piece IOL) and Softec HD (Lenstec)) were analyzed. The performance of Haigis, Barret Universal II and SKR-II formulas were compared between IOL types. The mean prediction error (ME) and mean absolute prediction error (MAE) were analyzed. Results: The overall percentage of eyes predicted within ±0.25 diopters (D) was 40.8% for Barret; 39.2% Haigis and 31.7% for SRK-II. Barret and Haigis had a significantly lower MAE than SRK-II (p < 0.05). The results differed among IOL types. The largest portion of eyes predicted within ±0.25 D was with the Barret formula in ZCB00 (33.3%) and ZA9003 (43.3%). Haigis was the most accurate in Softec HD (50%) and SRK-II in Biolline Yellow IOL (50%). ZCB00 showed a clinically significant hypermetropic ME compared to other IOLs. Conclusions: In general, Barret formulas had the best performance as a universal formula. However, the formula should be chosen according to the type of IOL in order to obtain the best results. Constant optimizations are necessary for the Tecnis IOL ZCB00 and ZA9003, as all of the analyzed formulas achieved a clinically significant poor performance in this type of IOL. ZCB00 also showed a hypermetropic shift in ME in all the formulas.

POSTPARTUM AMENORRHOEA IN RURAL EASTERN UTTAR PRADESH, INDIA

1998 ◽  
Vol 30 (2) ◽  
pp. 227-243
Author(s):  
K. N. S. YADAVA ◽  
S. K. JAIN
Keyword(s):  
Higher Education ◽  
Uttar Pradesh ◽  
Current Status Data ◽  
North India ◽  
Current Status ◽  
Data Sets ◽  
Survival Status ◽  
The Mean ◽  
The Difference ◽  
Using Data

This paper calculates the mean duration of the postpartum amenorrhoea (PPA) and examines its demographic, and socioeconomic correlates in rural north India, using data collected through 'retrospective' (last but one child) as well as 'current status' (last child) reporting of the duration of PPA.The mean duration of PPA was higher in the current status than in the retrospective data;n the difference being statistically significant. However, for the same mothers who gave PPA information in both the data sets, the difference in mean duration of PPA was not statistically significant. The correlates were identical in both the data sets. The current status data were more complete in terms of the coverage, and perhaps less distorted by reporting errors caused by recall lapse.A positive relationship of the mean duration of PPA was found with longer breast-feeding, higher parity and age of mother at the birth of the child, and the survival status of the child. An inverse relationship was found with higher education of a woman, higher education of her husband and higher socioeconomic status of her household, these variables possibly acting as proxies for women's better nutritional status.

Consistency of long-term marketable yield of carrot and onion cultivars in muck (organic) soil in relation to seasonal weather

2010 ◽  
Vol 90 (5) ◽  
pp. 755-765 ◽  
Author(s):  
M. T. Tesfaendrias ◽  
M. R. McDonald ◽  
J. Warland
Keyword(s):  
Allium Cepa ◽  
Daucus Carota ◽  
Organic Soil ◽  
Data Sets ◽  
Fresh Market ◽  
Marketable Yield ◽  
Daucus Carota L ◽  
Weather Patterns ◽  
The Mean

To identify carrot and onion cultivars that provide consistent marketable yields, we tracked the yields of five fresh market carrot [(Daucus carota L. subsp. sativus (Hoffm.) Arcang.] and six onion (Allium cepa L.) cultivars for at least 13 yr. Relationships between long-term weather variables and marketable yields were also investigated. The effects of cultivar, year and cultivar × year interactions on yield of carrots and onions were assessed. Cultivar and year had significant effects on carrot and onion yields, while the interaction was significant in only one of four data sets of carrot yield. Carrot cv. Cellobunch (95.4 t ha–1) and onion cv. Corona (74.1 t ha–1) had the highest mean marketable yields over the years studied. There was a slight positive correlation between mean yield of the assessed carrots and maximum temperatures in September (r = 0.44). Mean carrot yield was also somewhat negatively correlated with total rainfall in July (r = –0.43) and with number of days with rain in August (r = –0.43) and September (r = –0.44). Most onion cultivars showed stronger relationships between marketable yield and various weather patterns. Marketable yield of onions increased with an increase in the number of days with rainfall in June (r = 0.57). The mean marketable yield of the six onion cultivars decreased in relation to temperatures ≥30°C in June (r = –0.55) and August (r = –0.53). The mean yield of all the onions in the trials was negatively correlated (r = –0.78) with growing degree days (base 5°C, May to August). The results indicated that the data from long-term cultivar trials can be used to identify cultivars that yield well despite seasonal variations in weather. Key words: Daucus carota, Allium cepa, temperature, rainfall

scholarly journals The reproducibility of subjective appetite scores

1995 ◽  
Vol 73 (4) ◽  
pp. 517-530 ◽  
Author(s):  
Anne Raben ◽  
ANNA TAGLIABUE ◽  
Arne Astrup
Keyword(s):  
Visual Analogue Scale ◽  
Food Consumption ◽  
Analogue Scale ◽  
Prior Experience ◽  
Random Noise ◽  
Normal Weight ◽  
Vas Scores ◽  
The Mean ◽  
The Difference ◽  
Mean Differences

Although subjective appetite scores are widely used, studies on the reproducibility of this method are scarce. In the present study nine healthy, normal weight, young men recorded their subjective appetite sensations before and during 5 h after two different test meals A and B. The subjects tested each meal twice and in randomized order. Visual analogue scale (VAS) scores, 10 cm in length, were used to assess hunger, satiety, fullness, prospective food consumption and palatability of the meals. Plasma glucose and lactate concentrations were determined concomitantly. The repeatability was investigated for fasting values, Δ-mean 5 h and mean 5 h values, Δ-peak/nadir and peak/nadir values. Although the profiles of the postprandial responses were similar, the coefficients of repeatability (CR = 2SD) on the mean differences were large, ranging from 2·86 to 5.24 cm for fasting scores, 1·36 to 1·88 cm for mean scores, 2·98 to 5·42 cm for Δ-mean scores, and 3·16 to 6·44 cm for peak and Δ-peak scores. For palatability ratings the CK values varied more, ranging from 2·38 (taste) to 8·70 cm (aftertaste). Part of the difference in satiety ratings could be explained by the differences in palatability ratings. However, the low reproducibility may also be caused by a conditioned satiation or hunger due to the subjects' prior experience of the meals and therefore not just be a reflection of random noise. It is likely, however, that the variation in appetite ratings is due both to methodological day-to-day variation and to biological day-to-day variation in subjective appetite sensations.

Comparison of myocardial T1 mapping during breath-holding and free-breathing

2021 ◽  
pp. 1-5
Author(s):  
Hideharu Oka ◽  
Kouichi Nakau ◽  
Sadahiro Nakagawa ◽  
Yuki Kobayashi ◽  
Rina Imanishi ◽  
...  
Keyword(s):  
Cross Sections ◽  
T1 Mapping ◽  
Free Breathing ◽  
Breath Holding ◽  
Basal Region ◽  
Analysis Method ◽  
Imaging Analysis ◽  
Myocardial T1 ◽  
The Mean ◽  
Almost All

Abstract Background: T1 mapping is a recently developed imaging analysis method that allows quantitative assessment of myocardial T1 values obtained using MRI. In children, MRI is performed under free-breathing. Thus, it is important to know the changes in T1 values between free-breathing and breath-holding. This study aimed to compare the myocardial T1 mapping during breath-holding and free-breathing. Methods: Thirteen patients and eight healthy volunteers underwent cardiac MRI, and T1 values obtained during breath-holding and free-breathing were examined and compared. Statistical differences were determined using the paired t-test. Results: The mean T1 values during breath-holding were 1211.1 ± 39.0 ms, 1209.7 ± 37.4 ms, and 1228.9 ± 52.5 ms in the basal, mid, and apical regions, respectively, while the mean T1 values during free-breathing were 1165.1 ± 69.0 ms, 1103.7 ± 55.8 ms, and 1112.0 ± 81.5 ms in the basal, mid, and apical regions, respectively. The T1 values were lower during free-breathing than during breath-holding in almost all segments (basal: p = 0.008, mid: p < 0.001, apical: p < 0.001). The mean T1 values in each cross section were 3.1, 7.8, and 7.7% lower during free-breathing than during breath-holding in the basal, mid, and apical regions, respectively. Conclusions: We found that myocardial T1 values during free-breathing were about 3–8% lower in all cross sections than those during breath-holding. In free-breathing, it may be difficult to assess myocardial T1 values, except in the basal region, because of underestimation; thus, the findings should be interpreted with caution, especially in children.

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