scholarly journals The Minimum Detectable Difference (MDD) Concept for Establishing Trust in Nonsignificant Results: A Critical Review

2020 ◽  
Vol 39 (11) ◽  
pp. 2109-2123 ◽  
Author(s):  
Magdalena M. Mair ◽  
Mira Kattwinkel ◽  
Oliver Jakoby ◽  
Florian Hartig
Keyword(s):  
Critical Review ◽  
Detectable Difference ◽  
Minimum Detectable Difference

OPTIMIZING THE MINIMUM DETECTABLE DIFFERENCE OF COMPUTED TOMOGRAPHY SCANNED IMAGES VIA THE TAGUCHI ANALYSIS: A FEASIBILITY STUDY WITH AN INDIGENOUS HEPATIC PHANTOM AND A LINE GROUP GAUGE

2019 ◽  
Vol 19 (08) ◽  
pp. 1940048
Author(s):  
BING-RU PENG ◽  
SAMRIT KITTIPAYAK ◽  
LUNG-FA PAN ◽  
LUNG-KWANG PAN
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Optimization Analysis ◽  
Taguchi Analysis ◽  
Rotation Time ◽  
Detectable Difference ◽  
Minimum Detectable Difference ◽  
Optimal Setting ◽  
Scanned Images ◽  
Practical Factors

Objective: The minimum detectable difference (MDD) of computed tomography (CT) scanned images was quantified and optimized according to an indigenous hepatic phantom, line group gauge and Taguchi [Formula: see text] optimization analysis in this work. Methods: Optimal combinations of CT scan factors in every group with the level organization were judged using the Taguchi analysis, in which every factor was organized into only 18 groups, creating evaluated outcomes with the same confidence as if every factor was analyzed independently. The five practical factors of the CT scan were (1) kVp, (2) mAs, (3) pitch increment, (4) field of view (FOV) and (5) rotation time for one loop of CT scan. Insofar as each factor had two or three levels, the total number of 162 (i.e., [Formula: see text]) combinations was considered. Results: The optimal setting was 120[Formula: see text]kVp, 300[Formula: see text]mAs, 0.641 pitch, 320[Formula: see text]mm FOV and 1.0[Formula: see text]s of rotation time of CT scan. The minimal MDD was 2.65[Formula: see text]mm under 0.39[Formula: see text]mm of the slit depth from the revised Student’s [Formula: see text]-test with a 95% confidence level. In contrast, the MDD of conventional and the best one (no. 7) among all original 18 groups were 3.27[Formula: see text]mm and 2.93[Formula: see text]mm for 0.43[Formula: see text]mm and 0.41[Formula: see text]mm slit depths, respectively. Conclusion: The Taguchi analysis was found very lucrative for the design of imaging analysis in practical diagnosis. The indigenous line group gauge and hepatic phantom also proved to be suitable in simulating the human body in real hepatic carcinoma examination.

scholarly journals Quality Enhancement of Gamma Camera SPECT Images Via the Taguchi-Based Optimization of Their Minimum Detectable Difference And a V-Shaped Slit Gauge

2021 ◽  
Author(s):  
Ching-Hsiu Ke ◽  
Wan-Ju Liu ◽  
Bing-Ru Peng ◽  
Lung-Fa Pan ◽  
Lung-Kwang Pan
Keyword(s):  
Gamma Camera ◽  
Signal To Noise Ratio ◽  
Fish Bone ◽  
Line Pair ◽  
Matrix Size ◽  
Taguchi Analysis ◽  
Detectable Difference ◽  
Minimum Detectable Difference ◽  
Student’S T ◽  
Spect Images

Abstract Background: This study optimized the minimum detectable difference (MDD) of gamma camera SPECT images via the Taguchi analysis and an indigenous V-shaped slit gauge. The latter was customized to satisfy the Taguchi analysis’ quantitative requirements. Methods: The slit gauge MDD quantification of derived SPECT images was based on a pair of overlapped-peak profiles obtained from a tangent slice of the V-shaped slit with two adjacent peaks. Using the revised Student’s t-test with a multiplied constant, 1.96, the MDD was defined as the minimum distance between two peak centers, which deviation was large enough to ensure a 95% confidence level of their separation. In total, eighteen combinations of six gamma camera scanned factors (A-F), namely (A) collimator, (B) detector to target distance, (C) total counts, (D) acquired energy width, (E) Matrix size, and (F) zoom of collected ROI with each of two or three levels were organized into 18 groups to collect the slit gauge images according to Taguchi L18 orthogonal array. Next, three well-trained radiologists ranked the scanned gauge images to derive the fish-bone-plot of signal-to-noise ratio (S/N, dB) and correlated ANOVA. Results: The quantified MDD was proposed to verify the optimal suggestion of gamma camera scanned protocol, and obtained the MDD as 8.44, 7.88, and 7.40 mm for the 2nd group of the original L18, conventional, and optimal presets, respectively. Conclusions: The optimal preset of gamma camera was achieved according to Taguchi analysis. The MDD-based approach was found more beneficial in evaluating the spatial resolution than the line pair/cm approach in routine quality control in this study.

scholarly journals Reliability of a Test for Assessment of Isometric Trunk Muscle Strength in Elderly Women

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Marceli M. A. Mesquita ◽  
Marta S. Santos ◽  
Alan B. S. Vasconcelos ◽  
Clodoaldo A. de Sá ◽  
Luana C. D. Pereira ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Elderly Women ◽  
High Reliability ◽  
Isometric Strength ◽  
Lower Limbs ◽  
Cross Sectional ◽  
Interclass Correlation Coefficient ◽  
Interclass Correlation ◽  
Detectable Difference ◽  
Minimum Detectable Difference

Objective. The aim of this study was to analyze the reproducibility of a protocol using the maximal isometric strength test of the trunk in elderly women aged above 60 years, without low back pain. Methods. Twenty-one physically inactive elderly women, who had not engaged in any activity or exercise program in the past three months, participated in the cross-sectional study that consisted of two days of evaluations for the maximal isometric strength of the extensor and flexor muscles of the trunk, with a 48 h interval between the sessions. A platform with fixed seating was used, which allowed the fixation of the hip and lower limbs, with a load cell connected to a linear encoder. To verify the reliability of the test, the interclass correlation coefficient, variation coefficient, minimum detectable difference (MDD), standard error of measurement, and Bland–Altman graphs were calculated. Results. No statistical difference was observed between the first and second evaluation, which indicates that there was no learning effect. Interclass correlation coefficient values were classified as very high and high for extensor (0.98) and flexor (0.86) muscles, respectively, besides low variation (9% for both muscle groups) and acceptable values for minimum detectable difference (extensors = 51.1 N, flexors = 48.9 N). In addition, the Bland–Altman analysis revealed low bias and values within the limits of agreement. Conclusion. It is concluded that the test of maximum isometric strength of the trunk in healthy and trained elderly people presents high reliability. These values proved to be reliable if performed in at least two evaluation sessions, which confirms the hypothesis of the authors by the consistency of the measurement test.

TAGUCHI METHOD-BASED OPTIMIZATION OF THE MINIMUM DETECTABLE DIFFERENCE OF A CARDIAC X-RAY IMAGING SYSTEM USING A PRECISE LINE PAIR GAUGE

2019 ◽  
Vol 19 (07) ◽  
pp. 1940030 ◽  
Author(s):  
LUNG-FA PAN ◽  
KENG-YI WU ◽  
KE-LIN CHEN ◽  
SAMRIT KITTIPAYAK ◽  
LUNG-KWANG PAN
Keyword(s):  
Spatial Resolution ◽  
Imaging System ◽  
Low Noise ◽  
Optimal Combination ◽  
Line Pair ◽  
Test Analysis ◽  
X Ray ◽  
X Ray Imaging ◽  
Detectable Difference ◽  
Minimum Detectable Difference

Objective: To optimize the minimum detectable difference (MDD) of a cardiac X-ray imaging system using the Taguchi L8(27) analysis and a precise line pair (LP) gauge. Methods: The optimal combination of the four critical factors of the cardiac X-ray imaging system, namely X-ray focus, kilovoltage (kVp), milliamper-seconds (mAs) and source image distance (SID), providing the MDD was calculated via the Taguchi analysis and experimentally verified. Two (low and high) levels were assigned for each factor, and eight combinations of four factors were used to acquire instant X-ray images using an NDT commercial LP gauge (with a gauge length of 64[Formula: see text]mm and a width of [Formula: see text][Formula: see text]mm). The latter had five lines and was split gradually from top to bottom for the inspection of X-ray images, whose quality was ranked by three well-trained radiologists according to the double-blind criterion. The ranking grade was given by sharp contrast, low noise and precision to distinguish the LP. Accordingly, the MDD was derived to represent the spatial resolution of instant X-ray images by the revised Student’s [Formula: see text]-test analysis. The optimal combination of factors was experimentally identified and clinically verified in the follow-up inspections. Results: For the conventional setting, Group No. 7 (which obtained the highest grade among eight groups) and the optimal setting, the obtained MDD values were [Formula: see text], [Formula: see text] and [Formula: see text][Formula: see text]mm, respectively, while the LP (line pair/mm) interpolated from the gauge scale amounted to [Formula: see text], [Formula: see text] and [Formula: see text][Formula: see text]LP/mm, respectively. Conclusion: The Taguchi L8 analysis was proved to be instrumental in optimizing the cardiac X-ray imaging system MDD and is recommended to be used jointly with the revised Student’s [Formula: see text]-test analysis for improving the spatial resolution of instant X-ray images.

scholarly journals The minimum detectable difference (MDD) and the interpretation of treatment-related effects of pesticides in experimental ecosystems

2014 ◽  
Vol 22 (2) ◽  
pp. 1160-1174 ◽  
Author(s):  
T. C. M. Brock ◽  
M. Hammers-Wirtz ◽  
U. Hommen ◽  
T. G. Preuss ◽  
H-T. Ratte ◽  
...  
Keyword(s):  
Detectable Difference ◽  
Experimental Ecosystems ◽  
Minimum Detectable Difference

scholarly journals MINIMUM DETECTABLE DIFFERENCE OF CT ANGIOGRAPHY SCANS AT VARIOUS CARDIAC BEATS: EVALUATION VIA A CUSTOMIZED OBLIQUE V-SHAPED LINE GAUGE AND PMMA PHANTOM

2021 ◽  
Author(s):  
CHAO-YU CHIANG ◽  
YI-HUA CHEN ◽  
LUNG-FA PAN ◽  
CHIEN-CHOU CHO ◽  
BING-RU PENG ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Figure Of Merit ◽  
Signal To Noise Ratio ◽  
Quality Characteristic ◽  
Step Motor ◽  
Line Pair ◽  
Detectable Difference ◽  
Minimum Detectable Difference ◽  
Factor Combination ◽  
Scanned Images

The minimum detectable difference (MDD) at various beats/min (BPM) of CT angiography (CTA) was evaluated using an oblique V-shape line gauge and poly methyl methacrylate (PMMA) phantom in this study. The customized phantom with the size of [Formula: see text][Formula: see text]cm3 was made from a 1[Formula: see text]cm-thick PMMA. The reciprocating mechanism in the phantom was run by a step motor with an eccentric gear connected to a crank rod to provide a stable harmonic motion, simulating the cardiac beats. The MDD has a unique feature in defining the quality characteristic of CT-scanned images and provides more information than simple line pair/cm in the previous studies. The derived MDD was quantified according to various BPM, and the CTA factor combination was preset following either the conventional recommendation or the optimal one. In doing so, the performance was substantiated by the Taguchi-based signal-to-noise ratio and integrated by another index, namely, figure of merit (FOM). The MDD and corresponding [Formula: see text] (dB) changed from [Formula: see text][Formula: see text]mm to [Formula: see text][Formula: see text]mm and from 16.7[Formula: see text]dB to 14.2[Formula: see text]dB, respectively, for conventional settings; while those obtained for the optimal preset changed from [Formula: see text][Formula: see text]mm to [Formula: see text][Formula: see text]mm and from 12.2 dB to 16.4 dB, respectively of CTA at 0–90 BPM. The integrated FOM values for conventional or optimal cases were 1240 and 1337, respectively. The MDD proved to be a useful technique in justifying the CTA-scanned images. For compliance with previous studies, MDD results can be converted to the line pair/cm results, but it is more informative than the quantized number of line pairs.

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