Impact of inter-reader contouring variability on textural radiomics of colorectal liver metastases

Abstract Background Radiomics is expected to improve the management of metastatic colorectal cancer (CRC). We aimed at evaluating the impact of liver lesion contouring as a source of variability on radiomic features (RFs). Methods After Ethics Committee approval, 70 liver metastases in 17 CRC patients were segmented on contrast-enhanced computed tomography scans by two residents and checked by experienced radiologists. RFs from grey level co-occurrence and run length matrices were extracted from three-dimensional (3D) regions of interest (ROIs) and the largest two-dimensional (2D) ROIs. Inter-reader variability was evaluated with Dice coefficient and Hausdorff distance, whilst its impact on RFs was assessed using mean relative change (MRC) and intraclass correlation coefficient (ICC). For the main lesion of each patient, one reader also segmented a circular ROI on the same image used for the 2D ROI. Results The best inter-reader contouring agreement was observed for 2D ROIs according to both Dice coefficient (median 0.85, interquartile range 0.78–0.89) and Hausdorff distance (0.21 mm, 0.14–0.31 mm). Comparing RF values, MRC ranged 0–752% for 2D and 0–1567% for 3D. For 24/32 RFs (75%), MRC was lower for 2D than for 3D. An ICC > 0.90 was observed for more RFs for 2D (53%) than for 3D (34%). Only 2/32 RFs (6%) showed a variability between 2D and circular ROIs higher than inter-reader variability. Conclusions A 2D contouring approach may help mitigate overall inter-reader variability, albeit stable RFs can be extracted from both 3D and 2D segmentations of CRC liver metastases.

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3D Quantitative Ablation Margins for Prediction of Ablation Site Recurrence After Stereotactic Image-Guided Microwave Ablation of Colorectal Liver Metastases: A Multicenter Study

Frontiers in Oncology ◽

10.3389/fonc.2021.757167 ◽

2021 ◽

Vol 11 ◽

Author(s):

Simeon J. S. Ruiter ◽

Pascale Tinguely ◽

Iwan Paolucci ◽

Jennie Engstrand ◽

Daniel Candinas ◽

...

Keyword(s):

Liver Metastases ◽

Multicenter Study ◽

Microwave Ablation ◽

Colorectal Liver Metastases ◽

Liver Tumors ◽

Three Dimensional ◽

Multivariable Logistic Regression Analysis ◽

Tumor Diameter ◽

Ablation Margin ◽

The Impact

BackgroundThree-dimensional (3D) volumetric ablation margin assessment after thermal ablation of liver tumors using software has been described, but its predictive value on treatment efficacy when accounting for other factors known to correlate ablation site recurrence (ASR) remains unknown.PurposeTo investigate 3D quantitative ablation margins (3D-QAMs) as an algorithm to predict ASR within 1 year after stereotactic microwave ablation (SMWA) for colorectal liver metastases (CRLM).Materials and MethodsSixty-five tumors in 47 patients from a prospective multicenter study of patients undergoing SMWA for CRLM were included in this retrospective 3D-QAM analysis. Using a previously developed algorithm, 3D-QAM defined as the distribution of tumor to ablation surface distances was assessed in co-registered pre- and post-ablation CT scans. The discriminatory power and optimal cutoff values for 3D-QAM were assessed using receiver operating characteristic (ROC) curves. Multivariable logistic regression analysis using generalized estimating equations was applied to investigate the impact of various 3D-QAM outputs on 1-year ASR while accounting for other known influencing factors.ResultsTen of the 65 (15.4%) tumors included for 3D-QAM analysis developed ASR. ROC analyses identified i) 3D-QAM <1 mm for >23% of the tumor surface, ii) 3D-QAM <5 mm for >45%, and iii) the minimal ablation margin (MAM) as the 3D-QAM outputs with optimal discriminatory qualities. The multivariable regression model without 3D-QAM yielded tumor diameter and KRAS mutation as 1-year ASR predictors. When adding 3D-QAM, this factor became the main predictor of 1-year ASR [odds ratio (OR) 21.67 (CI 2.48, 165.21) if defined as >23% <1 mm; OR 0.52 (CI 0.29, 0.95) if defined as MAM].Conclusions3D-QAM allows objectifiable and standardized assessment of tumor coverage by the ablation zone after SMWA. Our data shows that 3D-QAM represents the most important factor predicting ASR within 1 year after SMWA of CRLM.

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Image Contrast, Image Pre-Processing, and T1 Mapping Affect MRI Radiomic Feature Repeatability in Patients with Colorectal Cancer Liver Metastases

Cancers ◽

10.3390/cancers13020240 ◽

2021 ◽

Vol 13 (2) ◽

pp. 240

Author(s):

Damien J. McHugh ◽

Nuria Porta ◽

Ross A. Little ◽

Susan Cheung ◽

Yvonne Watson ◽

...

Keyword(s):

Colorectal Cancer ◽

Liver Metastases ◽

Intraclass Correlation ◽

Imaging Biomarkers ◽

Sequence Comparisons ◽

Colorectal Cancer Liver Metastases ◽

T1 And T2 ◽

Non Gaussian ◽

The Impact ◽

T2 Weighted Images

Imaging biomarkers require technical, biological, and clinical validation to be translated into robust tools in research or clinical settings. This study contributes to the technical validation of radiomic features from magnetic resonance imaging (MRI) by evaluating the repeatability of features from four MR sequences: pre-contrast T1- and T2-weighted images, pre-contrast quantitative T1 maps (qT1), and contrast-enhanced T1-weighted images. Fifty-one patients with colorectal cancer liver metastases were scanned twice, up to 7 days apart. Repeatability was quantified using the intraclass correlation coefficient (ICC) and repeatability coefficient (RC), and the impact of non-Gaussian feature distributions and image normalisation was evaluated. Most radiomic features had non-Gaussian distributions, but Box–Cox transformations enabled ICCs and RCs to be calculated appropriately for an average of 97% of features across sequences. ICCs ranged from 0.30 to 0.99, with volume and other shape features tending to be most repeatable; volume ICC > 0.98 for all sequences. 19% of features from non-normalised images exhibited significantly different ICCs in pair-wise sequence comparisons. Normalisation tended to increase ICCs for pre-contrast T1- and T2-weighted images, and decrease ICCs for qT1 maps. RCs tended to vary more between sequences than ICCs, showing that evaluations of feature performance depend on the chosen metric. This work suggests that feature-specific repeatability, from specific combinations of MR sequence and pre-processing steps, should be evaluated to select robust radiomic features as biomarkers in specific studies. In addition, as different repeatability metrics can provide different insights into a specific feature, consideration of the appropriate metric should be taken in a study-specific context.

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Peripheral extent of the choroidal circulation by ultra-widefield indocyanine green angiography in healthy eyes

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2020-316412 ◽

2020 ◽

pp. bjophthalmol-2020-316412

Author(s):

Aditya Verma ◽

Jyotsna Maram ◽

Ahmed Roshdy Alagorie ◽

Jano van Hemert ◽

Darren J Bell ◽

...

Keyword(s):

Indocyanine Green ◽

Indocyanine Green Angiography ◽

Intraclass Correlation ◽

Three Dimensional ◽

Radial Distance ◽

Three Dimensional Model ◽

Choroidal Circulation ◽

The Mean ◽

The Impact ◽

Healthy Eyes

AimTo analyse the peripheral extent of choroidal circulation using ultra-widefield (UWF) indocyanine green angiography (ICGA) in healthy eyes.MethodsUWF ICGA images of 55 eyes of 36 healthy subjects were captured using the Optos California (Optos, Dunfermline, United Kingdom) in this prospective observational study. Images were analysed to locate the peripheral extent of the visible choroidal circulation, and the boundary was marked in ImageJ (v1.52). Each pixel annotated as the border of the choroidal circulation was projected individually to its anatomically correct location on the three-dimensional model eye, and spherical trigonometry was applied (using the Optos software) to calculate its respective radial distance from the centre of the optic disc in metric units (corrected by stereographic projection) for each quadrant.ResultsThe mean area of the peripheral extent was estimated to be 893.2 mm2 (95% CI: 844.2 to 942.3 mm2). The mean distance (range) of this boundary from optic nerve centre was 18.22 mm (95% CI: 14.0 to 23.14 mm). Multiple regression analysis with age, gender, axial length or ethnicity showed no relationship. There was excellent inter-grader reproducibility, with intraclass correlation coefficients of 0.95 (95% CI: 0.80 to 0.99, p<0.001) for distance and 0.99 (95% CI: 0.988 to 0.999, p<0.001) for area measurements.ConclusionsThe peripheral choroidal boundary may be defined using UWF ICGA. Knowledge of the normal extent and its variability is essential to understand the impact of disease on the choroidal vasculature.

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Analyzing the Impact of X-Ray Tomography on the Reliability of Integrated Circuits

ISTFA 2015: Conference Proceedings from the 41st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2015p0154 ◽

2015 ◽

Author(s):

Halit Dogan ◽

Md Mahbub Alam ◽

Navid Asadizanjani ◽

Sina Shahbazmohamadi ◽

Domenic Forte ◽

...

Keyword(s):

Integrated Circuits ◽

Integrated Circuit ◽

3D Imaging ◽

Three Dimensional ◽

Serial Sectioning ◽

Promising Technique ◽

Flash Memories ◽

X Ray ◽

3D Information ◽

The Impact

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

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Numerical simulation of the impact of an integrated renovation project on the Maowei Sea hydrodynamic environment

Scientific Reports ◽

10.1038/s41598-021-96441-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Cui Wang ◽

Ling Cai ◽

Yaojian Wu ◽

Yurong Ouyang

Keyword(s):

Water Exchange ◽

Land Reclamation ◽

Three Dimensional ◽

Exchange Capacity ◽

Reclamation Project ◽

Hydrodynamic Environment ◽

Sea Area ◽

Water Quality Models ◽

The Impact ◽

Main Factor

AbstractIntegrated renovation projects are important for marine ecological environment protection. Three-dimensional hydrodynamics and water quality models are developed for the Maowei Sea to assess the hydrodynamic environment base on the MIKE3 software with high resolution meshes. The results showed that the flow velocity changed minimally after the project, decreasing by approximately 0.12 m/s in the east of the Maowei Sea area and increasing by approximately 0.01 m/s in the northeast of the Shajing Port. The decrease in tidal prism (~ 2.66 × 106 m3) was attributed to land reclamation, and accounted for just 0.86% of the pre-project level. The water exchange half-life increased by approximately 1 day, implying a slightly reduced water exchange capacity. Siltation occurred mainly in the reclamation and dredging areas, amounting to back-silting of approximately 2 cm/year. Reclamation project is the main factor causing the decrease of tidal volume and weakening the hydrodynamics in Maowei Sea. Adaptive management is necessary for such a comprehensive regulation project. According to the result, we suggest that reclamation works should strictly prohibit and dredging schemes should optimize in the subsequent regulation works.

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Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽

10.3390/min11020213 ◽

2021 ◽

Vol 11 (2) ◽

pp. 213

Author(s):

Hamid Ait Said ◽

Hassan Noukrati ◽

Hicham Ben Youcef ◽

Ayoub Bayoussef ◽

Hassane Oudadesse ◽

...

Keyword(s):

Molecular Weight ◽

Compressive Strength ◽

Mechanical Strength ◽

Bone Repair ◽

Mechanical Stability ◽

Three Dimensional ◽

Processing Parameters ◽

Composite Effect ◽

Solid Liquid ◽

The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

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Fully automated preoperative segmentation of temporal bone structures from clinical CT scans

Scientific Reports ◽

10.1038/s41598-020-80619-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

C. A. Neves ◽

E. D. Tran ◽

I. M. Kessler ◽

N. H. Blevins

Keyword(s):

Facial Nerve ◽

Inner Ear ◽

Temporal Bone ◽

Hausdorff Distance ◽

Sigmoid Sinus ◽

Ct Scans ◽

Automated Segmentation ◽

Dice Coefficient ◽

Lateral Skull Base ◽

End To End

AbstractMiddle- and inner-ear surgery is a vital treatment option in hearing loss, infections, and tumors of the lateral skull base. Segmentation of otologic structures from computed tomography (CT) has many potential applications for improving surgical planning but can be an arduous and time-consuming task. We propose an end-to-end solution for the automated segmentation of temporal bone CT using convolutional neural networks (CNN). Using 150 manually segmented CT scans, a comparison of 3 CNN models (AH-Net, U-Net, ResNet) was conducted to compare Dice coefficient, Hausdorff distance, and speed of segmentation of the inner ear, ossicles, facial nerve and sigmoid sinus. Using AH-Net, the Dice coefficient was 0.91 for the inner ear; 0.85 for the ossicles; 0.75 for the facial nerve; and 0.86 for the sigmoid sinus. The average Hausdorff distance was 0.25, 0.21, 0.24 and 0.45 mm, respectively. Blinded experts assessed the accuracy of both techniques, and there was no statistical difference between the ratings for the two methods (p = 0.93). Objective and subjective assessment confirm good correlation between automated segmentation of otologic structures and manual segmentation performed by a specialist. This end-to-end automated segmentation pipeline can help to advance the systematic application of augmented reality, simulation, and automation in otologic procedures.

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A New Method to Evaluate Trueness and Precision of Digital and Conventional Impression Techniques for Complete Dental Arch

Applied Sciences ◽

10.3390/app11104612 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4612

Author(s):

KweonSoo Seo ◽

Sunjai Kim

Keyword(s):

Intraclass Correlation ◽

Three Dimensional ◽

New Method ◽

Digital Impression ◽

Dental Arch ◽

Digital Models ◽

Digital Impressions ◽

Measuring Machine ◽

Master Model ◽

Conventional Impression

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twenty-five definitive stone casts were fabricated using conventional impressions of the master model. An intraoral scanner was used to scan the master model 25 times to fabricate 25 digital models. A coordinate measuring machine was used to physically probe each cylinder in the master model and definitive casts. An inspection software was used to probe cylinders of digital models. A three-dimensional part coordinate system was defined and used to compute the centroid coordinate of each cylinder. Intraclass correlation coefficient (ICC) was evaluated to examine the reliability of the new method. Independent two sample t-test was performed to compare the trueness and precision of conventional and intraoral digital impressions (α = 0.05). Results: ICC results showed that, the new method had almost perfect reliability for the measurements of the master model, conventional and digital impression. Conventional impression showed more accurate absolute trueness and precision than intraoral digital impression for most of the tooth positions (p < 0.05). Conclusions: The new method was reliable to analyze the three-dimensional deviation of complete-arch impressions. Conventional impression was still more accurate than digital intraoral impression for complete arches.

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Examining the Impact of and Sensitivity of Fit Indices to Omitting Covariates Interaction Effect in Multilevel Multiple-Indicator Multiple-Cause Models

Educational and Psychological Measurement ◽

10.1177/0013164421992407 ◽

2021 ◽

pp. 001316442199240

Author(s):

Chunhua Cao ◽

Eun Sook Kim ◽

Yi-Hsin Chen ◽

John Ferron

Keyword(s):

Root Mean Square ◽

Interaction Effect ◽

Intraclass Correlation ◽

Information Criteria ◽

Parameter Estimates ◽

Mean Square ◽

Fit Indices ◽

Cluster Number ◽

Multiple Indicator ◽

The Impact

This study examined the impact of omitting covariates interaction effect on parameter estimates in multilevel multiple-indicator multiple-cause models as well as the sensitivity of fit indices to model misspecification when the between-level, within-level, or cross-level interaction effect was left out in the models. The parameter estimates produced in the correct and the misspecified models were compared under varying conditions of cluster number, cluster size, intraclass correlation, and the magnitude of the interaction effect in the population model. Results showed that the two main effects were overestimated by approximately half of the size of the interaction effect, and the between-level factor mean was underestimated. None of comparative fit index, Tucker–Lewis index, root mean square error of approximation, and standardized root mean square residual was sensitive to the omission of the interaction effect. The sensitivity of information criteria varied depending majorly on the magnitude of the omitted interaction, as well as the location of the interaction (i.e., at the between level, within level, or cross level). Implications and recommendations based on the findings were discussed.

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Efficacy of Surgery for the Treatment of Gastric Cancer Liver Metastases: A Systematic Review of the Literature and Meta-Analysis of Prognostic Factors

Journal of Clinical Medicine ◽

10.3390/jcm10051141 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1141

Author(s):

Gianpaolo Marte ◽

Andrea Tufo ◽

Francesca Steccanella ◽

Ester Marra ◽

Piera Federico ◽

...

Keyword(s):

Gastric Cancer ◽

Systematic Review ◽

Prognostic Factors ◽

Liver Metastases ◽

Meta Analysis ◽

Multidisciplinary Treatment ◽

Review Of The Literature ◽

Term Survival ◽

The Impact

Background: In the last 10 years, the management of patients with gastric cancer liver metastases (GCLM) has changed from chemotherapy alone, towards a multidisciplinary treatment with liver surgery playing a leading role. The aim of this systematic review and meta-analysis is to assess the efficacy of hepatectomy for GCLM and to analyze the impact of related prognostic factors on long-term outcomes. Methods: The databases PubMed (Medline), EMBASE, and Google Scholar were searched for relevant articles from January 2010 to September 2020. We included prospective and retrospective studies that reported the outcomes after hepatectomy for GCLM. A systematic review of the literature and meta-analysis of prognostic factors was performed. Results: We included 40 studies, including 1573 participants who underwent hepatic resection for GCLM. Post-operative morbidity and 30-day mortality rates were 24.7% and 1.6%, respectively. One-year, 3-years, and 5-years overall survival (OS) were 72%, 37%, and 26%, respectively. The 1-year, 3-years, and 5-years disease-free survival (DFS) were 44%, 24%, and 22%, respectively. Well-moderately differentiated tumors, pT1–2 and pN0–1 adenocarcinoma, R0 resection, the presence of solitary metastasis, unilobar metastases, metachronous metastasis, and chemotherapy were all strongly positively associated to better OS and DFS. Conclusion: In the present study, we demonstrated that hepatectomy for GCLM is feasible and provides benefits in terms of long-term survival. Identification of patient subgroups that could benefit from surgical treatment is mandatory in a multidisciplinary setting.

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