PeerJ Preprints: Radiology and Medical Imaginghttps://peerj.com/preprints/index.atom?journal=peerj&subject=6600Radiology and Medical Imaging articles published in PeerJ PreprintsStandardized representation of the LIDC annotations using DICOMhttps://peerj.com/preprints/273782019-05-202019-05-20Andrey FedorovMatthew HancockDavid ClunieMathias BrochhausenJonathan BonaJustin KirbyJohn FreymannSteve PieperHugo AertsRon KikinisFred Prior
The Lung Imaging Data Consortium and Image Database Resource Initiative (LIDC) conducted a multi-site reader study that produced a comprehensive database of Computed Tomography (CT) scans for over 1000 subjects annotated by multiple expert readers. The result is hosted in the LIDC-IDRI collection of The Cancer Imaging Archive (TCIA). Annotations that accompany the images of the collection are stored using project-specific XML representation. This complicates their reuse, since no general-purpose tools are available to visualize or query those objects, and makes harmonization with other similar type of data non-trivial. To make the LIDC dataset more FAIR (Findable, Accessible, Interoperable, Reusable) to the research community, we prepared their standardized representation using the Digital Imaging and Communications in Medicine (DICOM) standard. This manuscript is intended to serve as a companion to the dataset to facilitate its reuse.
The Lung Imaging Data Consortium and Image Database Resource Initiative (LIDC) conducted a multi-site reader study that produced a comprehensive database of Computed Tomography (CT) scans for over 1000 subjects annotated by multiple expert readers. The result is hosted in the LIDC-IDRI collection of The Cancer Imaging Archive (TCIA). Annotations that accompany the images of the collection are stored using project-specific XML representation. This complicates their reuse, since no general-purpose tools are available to visualize or query those objects, and makes harmonization with other similar type of data non-trivial. To make the LIDC dataset more FAIR (Findable, Accessible, Interoperable, Reusable) to the research community, we prepared their standardized representation using the Digital Imaging and Communications in Medicine (DICOM) standard. This manuscript is intended to serve as a companion to the dataset to facilitate its reuse.Brasilia Parkinson Cohort: assessing clinical, neuropsychological and imaging predictors of cognitive decline in Parkinson's diseasehttps://peerj.com/preprints/276392019-04-052019-04-05Pedro Renato de Paula BrandãoFernando Bisinoto MalufTalyta GrippeIngrid FaberDanilo Assis PereiraNasser AllamFrancisco E.C. CardosoCarlos TomazMaria Clotilde H Tavares
The following study protocol describes the rationale and methods of a cohort with a nested case-control study, which aims to identify risk factors and predictors of cognitive dysfunction in Parkinson's disease (PD). It is a study that will follow PD every 18 months with a comprehensive neuropsychological, clinical (motor and non-motor symptoms) and imaging (Magnetic Resonance Imaging) data collection. The criteria for diagnosing mild cognitive impairment (MCI) and dementia will respect the parameters previously published by the International Working Group on Mild Cognitive Impairment, and compared with those recommended by the Fifth edition of the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-5) and the International Parkinson's and Movement Disorders Society (MDS) criteria. We will also evaluate the neural substrate and underpinnings of PD non-motor symptoms, using advanced neuroimaging techniques, such as diffusion tensor imaging (DTI) and gray matter and white matter volumetric measurements.
The following study protocol describes the rationale and methods of a cohort with a nested case-control study, which aims to identify risk factors and predictors of cognitive dysfunction in Parkinson's disease (PD). It is a study that will follow PD every 18 months with a comprehensive neuropsychological, clinical (motor and non-motor symptoms) and imaging (Magnetic Resonance Imaging) data collection. The criteria for diagnosing mild cognitive impairment (MCI) and dementia will respect the parameters previously published by the International Working Group on Mild Cognitive Impairment, and compared with those recommended by the Fifth edition of the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-5) and the International Parkinson's and Movement Disorders Society (MDS) criteria. We will also evaluate the neural substrate and underpinnings of PD non-motor symptoms, using advanced neuroimaging techniques, such as diffusion tensor imaging (DTI) and gray matter and white matter volumetric measurements.An automatic fascicle tracking algorithm quantifying gastrocnemius architecture during maximal effort contractionshttps://peerj.com/preprints/274752019-01-102019-01-10John F DrazanTodd J HullfishJosh R Baxter
Background. Ultrasound has become the gold-standard for making dynamic measurements of muscle structure during functional movements in biomechanical studies. Manual measurements of fascicle length and pennation angle are time intensive which limits the clinical utility of this approach while also limiting sample sizes. The purpose of this study was to develop a novel tracking paradigm to quantify individual fascicle length and pennation measurements during maximal voluntary contractions and demonstrate is repeatability between days and reproducibility between different examiners.
Methods. Five healthy young adults performed maximal isokinetic contractions at 0, 30, 120, 210, and 500 degrees about their ankle on an isokinetic dynamometer while their gastrocnemius muscle was observed using ultrasound. Individual muscle fascicles were identified in the first frame, and tracked using the automatic fascicle tracking algorithm and a manual approach by three observers on three separate days. Repeatability within examiners across days and reproducibility across examiners and days was evaluated using intraclass correlation coefficients. Agreement between manual and automatic tracking was evaluated using the coefficient of multiple correlations. Supervised automatic tracking was performed on all videos by one examiner to evaluate the fidelity of automatic tracking in practice.
Results. We found both manual and automatic measurements of fascicle length and pennation angle to be strongly repeatable within examiners and strongly reproducible across examiners and days (ICCs>0.76). There was greater agreement between manual and automatic measurements of fascicle length than pennation angle, however the mean CMC value for both was still found to be strong in both cases (CMC>0.8). Supervision of automatic tracking greatly showed very strong agreement between manual and automatic measurements of fascicle length and pennation angle (CMC>0.94).
Conclusions. We have developed a novel automatic fascicle tracking algorithm that quantifies fascicle length and pennation angle of individual muscle fascicles during dynamic contractions across a range of velocities. We demonstrated that this fascicle tracking algorithm is repeatable and reproducible across different examiners and different days and showed strong agreement with manual measurements, especially when tracking is supervised by the user so that tracking can be reinitialized if poor tracking fidelity is observed.
Background. Ultrasound has become the gold-standard for making dynamic measurements of muscle structure during functional movements in biomechanical studies. Manual measurements of fascicle length and pennation angle are time intensive which limits the clinical utility of this approach while also limiting sample sizes. The purpose of this study was to develop a novel tracking paradigm to quantify individual fascicle length and pennation measurements during maximal voluntary contractions and demonstrate is repeatability between days and reproducibility between different examiners.Methods. Five healthy young adults performed maximal isokinetic contractions at 0, 30, 120, 210, and 500 degrees about their ankle on an isokinetic dynamometer while their gastrocnemius muscle was observed using ultrasound. Individual muscle fascicles were identified in the first frame, and tracked using the automatic fascicle tracking algorithm and a manual approach by three observers on three separate days. Repeatability within examiners across days and reproducibility across examiners and days was evaluated using intraclass correlation coefficients. Agreement between manual and automatic tracking was evaluated using the coefficient of multiple correlations. Supervised automatic tracking was performed on all videos by one examiner to evaluate the fidelity of automatic tracking in practice.Results. We found both manual and automatic measurements of fascicle length and pennation angle to be strongly repeatable within examiners and strongly reproducible across examinersand days (ICCs>0.76). There was greater agreement between manual and automatic measurements of fascicle length than pennation angle, however the mean CMC value for both was still found to be strong in both cases (CMC>0.8). Supervision of automatic tracking greatly showed very strong agreement between manual and automatic measurements of fascicle length and pennation angle (CMC>0.94).Conclusions. We have developed a novel automatic fascicle tracking algorithm that quantifies fascicle length and pennation angle of individual muscle fascicles during dynamic contractions across a range of velocities. We demonstrated that this fascicle tracking algorithm is repeatable and reproducible across different examiners and different days and showed strong agreement with manual measurements, especially when tracking is supervised by the user so that tracking can be reinitialized if poor tracking fidelity is observed.Is it possible to reduce file numbers of conventional rotary systems?https://peerj.com/preprints/266412018-03-082018-03-08Gül CelikMurat MadenAhmet SavgatHikmet Orhan
Backround: frequent introduction of new dental instruments or devices into the market has been a concern for dentists worldwide, as the prices of such instruments are generally high, especially in developing countries. In addition, the use of these tools requires new skills and experience. For this reason, while innovations in dentistry are being pursued, it may be advantageous to update the dental instruments that we have been using for years. This study evaluated whether both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals.
Methods: A total of 45 simulated canals with 40o curvature in clear resin blocks were prepared with conventional rotary systems: ProFile orifice shaping (OS) #3 and final flaring #25/.06, Reciproc R25, and ProTaper shaping file SX and finishing file F2. Pre- and post-instrumentation views were analysed using digital images captured by a camera. Prepared inner and outer walls at 1–10 levels were measured using AutoCAD software. The time required for canal shaping and the frequency of broken instruments were recorded. Standardised pre- and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analysed using the one-way multivariate analysis of variance (ANOVA) and least significant difference test. The level of significance was set at 0.05. The transportation, instrumentation time, change of WL, and instrumentation fractures were evaluated. Data were analysed by ANOVA, Kruskal–Wallis and independent t-test (p<0.05).
Results: Reciproc removed more mass in total and caused less transportation in the middle and coronal third (p<0.001). The transportations performed in the apical third were opposite to the curve. There was no significant difference among the groups in terms of maintaining the original WL. Reciproc was significantly faster (p<0.001). Only one instrument fracture (25/0.06 ProFile) was noted. All groups showed one ledge each.
Discussion: According to this study, both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals. However, Reciproc, which was produced using a single-file concept, was determined to be more advantageous in terms of time. This study suggests that the conventional rotary technique system might have comparable efficacy to the single-file system for root canal shaping.
Backround: frequent introduction of new dental instruments or devices into the market has been a concern for dentists worldwide, as the prices of such instruments are generally high, especially in developing countries. In addition, the use of these tools requires new skills and experience. For this reason, while innovations in dentistry are being pursued, it may be advantageous to update the dental instruments that we have been using for years. This study evaluated whether both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals.Methods: A total of 45 simulated canals with 40o curvature in clear resin blocks were prepared with conventional rotary systems: ProFile orifice shaping (OS) #3 and final flaring #25/.06, Reciproc R25, and ProTaper shaping file SX and finishing file F2. Pre- and post-instrumentation views were analysed using digital images captured by a camera. Prepared inner and outer walls at 1–10 levels were measured using AutoCAD software. The time required for canal shaping and the frequency of broken instruments were recorded. Standardised pre- and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analysed using the one-way multivariate analysis of variance (ANOVA) and least significant difference test. The level of significance was set at 0.05. The transportation, instrumentation time, change of WL, and instrumentation fractures were evaluated. Data were analysed by ANOVA, Kruskal–Wallis and independent t-test (p<0.05).Results: Reciproc removed more mass in total and caused less transportation in the middle and coronal third (p<0.001). The transportations performed in the apical third were opposite to the curve. There was no significant difference among the groups in terms of maintaining the original WL. Reciproc was significantly faster (p<0.001). Only one instrument fracture (25/0.06 ProFile) was noted. All groups showed one ledge each.Discussion: According to this study, both ProFile and ProTaper files have the potential to reduce the number of files required for shaping curved root canals. However, Reciproc, which was produced using a single-file concept, was determined to be more advantageous in terms of time. This study suggests that the conventional rotary technique system might have comparable efficacy to the single-file system for root canal shaping.Detection of linear features including bone and skin areas in ultrasound images of jointshttps://peerj.com/preprints/35192018-01-102018-01-10Artur BąkJakub SegenKamil WereszczyńskiPawel MielnikMarcin FojcikMarek Kulbacki
Identifying the separate parts in ultrasound images such as bone and skin plays the crucial role in synovitis detection task. This paper presents a detector of bone and skin regions in the form of a classifier which is trained on a set of annotated images. Selected regions have labels: skin or bone or none. Feature vectors used by the classifier are assigned to image pixels as a result of passing the image through the bank of linear and nonlinear filters. The filters include Gaussian blurring filter, its first and second order derivatives, Laplacian as well as positive and negative threshold operations applied to the filtered images. We compared multiple supervised learning classifiers including Naive Bayes, k-Nearest Neighbour, Decision Trees, Random Forest, AdaBoost and Support Vector Machines (SVM) with various kernels, using four classification performance scores and computation time. The Random Forest classifier was selected for the final use, as it gives the best overall evaluation results.
Identifying the separate parts in ultrasound images such as bone and skin plays the crucial role in synovitis detection task. This paper presents a detector of bone and skin regions in the form of a classifier which is trained on a set of annotated images. Selected regions have labels: skin or bone or none. Feature vectors used by the classifier are assigned to image pixels as a result of passing the image through the bank of linear and nonlinear filters. The filters include Gaussian blurring filter, its first and second order derivatives, Laplacian as well as positive and negative threshold operations applied to the filtered images. We compared multiple supervised learning classifiers including Naive Bayes, k-Nearest Neighbour, Decision Trees, Random Forest, AdaBoost and Support Vector Machines (SVM) with various kernels, using four classification performance scores and computation time. The Random Forest classifier was selected for the final use, as it gives the best overall evaluation results.Single phase computed tomography is equivalent to dual phase method for localizing hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism: A retrospective reviewhttps://peerj.com/preprints/30582017-06-292017-06-29Fanny MoronAlfred DelumpaJustin ChettaDanielle GuffeyDavid Dunaway
Objective: This study aims to compare the sensitivity of dual phase (non-contrast and arterial) versus single phase (arterial) CT for detection of hyper-functioning parathyroid glands in patients with primary hyperparathyroidism. Methods: The CT scans of thirty-two patients who have biochemical evidence of primary hyperparathyroidism, pathologically proven parathyroid adenomas, and pre-operative multiphase parathyroid imaging were evaluated retrospectively in order to compare the adequacy of single phase vs. dual phase CT scans for the detection of parathyroid adenomas. Results: The parathyroid adenomas were localized in 83% of cases on single arterial phase CT and 80% of cases on dual phase CT. The specificity for localization of parathyroid tumor was 96% for single phase CT and 97% for dual phase CT. The results were not significantly different (p=0.695). These results are similar to those found in the literature for multiphase CT of 55-94%. Conclusions: Our study supports the use of a single arterial phase CT for the detection of hyperfunctioning parathyroid adenomas. Advances in knowledge: A single arterial phase CT has similar sensitivity for localizing parathyroid adenomas as dual phase CT and significantly reduces radiation dose to the patient.
Objective: This study aims to compare the sensitivity of dual phase (non-contrast and arterial) versus single phase (arterial) CT for detection of hyper-functioning parathyroid glands in patients with primary hyperparathyroidism. Methods: The CT scans of thirty-two patients who have biochemical evidence of primary hyperparathyroidism, pathologically proven parathyroid adenomas, and pre-operative multiphase parathyroid imaging were evaluated retrospectively in order to compare the adequacy of single phase vs. dual phase CT scans for the detection of parathyroid adenomas. Results: The parathyroid adenomas were localized in 83% of cases on single arterial phase CT and 80% of cases on dual phase CT. The specificity for localization of parathyroid tumor was 96% for single phase CT and 97% for dual phase CT. The results were not significantly different (p=0.695). These results are similar to those found in the literature for multiphase CT of 55-94%. Conclusions: Our study supports the use of a single arterial phase CT for the detection of hyperfunctioning parathyroid adenomas. Advances in knowledge: A single arterial phase CT has similar sensitivity for localizing parathyroid adenomas as dual phase CT and significantly reduces radiation dose to the patient.Methodological considerations in assessment of language lateralisation with fMRI: a systematic reviewhttps://peerj.com/preprints/29622017-05-042017-05-04Abigail R. BradshawDorothy V. M. BishopZoe V. J. Woodhead
The involvement of the right and left hemispheres in mediating language functions has been measured in a variety of ways over the centuries since the relative dominance of the left hemisphere was first known. Functional magnetic resonance imaging (fMRI) presents a useful non-invasive method of assessing lateralisation that is being increasingly used in clinical practice and research. However, the methods used in the fMRI laterality literature currently are highly variable, making systematic comparisons across studies difficult. Here we consider the different methods of quantifying and classifying laterality that have been used in fMRI studies since 2000, with the aim of determining which give the most robust and reliable measurement. Recommendations are made with a view to informing future research to increase standardisation in fMRI laterality protocols. In particular, the findings reinforce the importance of threshold-independent methods for calculating laterality indices, and the benefits of assessing heterogeneity of language laterality across multiple regions of interest and tasks.
The involvement of the right and left hemispheres in mediating language functions has been measured in a variety of ways over the centuries since the relative dominance of the left hemisphere was first known. Functional magnetic resonance imaging (fMRI) presents a useful non-invasive method of assessing lateralisation that is being increasingly used in clinical practice and research. However, the methods used in the fMRI laterality literature currently are highly variable, making systematic comparisons across studies difficult. Here we consider the different methods of quantifying and classifying laterality that have been used in fMRI studies since 2000, with the aim of determining which give the most robust and reliable measurement. Recommendations are made with a view to informing future research to increase standardisation in fMRI laterality protocols. In particular, the findings reinforce the importance of threshold-independent methods for calculating laterality indices, and the benefits of assessing heterogeneity of language laterality across multiple regions of interest and tasks.A clinical assessment of external beam focal therapy for localized prostate cancer measured by Gafchromic filmhttps://peerj.com/preprints/29382017-04-212017-04-21Kurt W Van Delinder
Background: Traditionally, EBRT prostate treatments have been administered using three different techniques: three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). These radiation therapy treatment techniques are often combined with additional options focusing on treating systemic disease and the entire volume of the prostate. A novel approach to EBRT is currently in development, a localized treatment administered to only the primary disease within the prostate volume termed ‘Focal Therapy’.
Methods/Design: The proposed research study is aimed to simulate 10 random EBRT prostate focal therapy treatments replicated within two treatment planning software; Monaco treatment planning system and Eclipse treatment planning system. All ten plans will be contoured simulations of focal therapy imaging sets replicated from authentic mpMRI anatomical images of focal therapy eligible prostate cancer patients. Following the completion of the 10 clinical plans, QA plans will be generated and administered via each products current commercial linacs; the TrueBeam and the Versa. All QA plans will have their radiation doses measured with Gafchromic EBT3 radiochromic film and analyzed using the gamma analysis index (γ).
Discussion: To examine the uncertainties and limitations of an EBRT focal therapy prostate cancer treatment, it’s imperative that a large study replicating many clinical cases under varying conditions should be conducted. This allows the ability for the clinician to investigate errors and uncertainties at each stage of the treatment process prior to committing to a clinical study. The experimental results can also be used as a reference for the creation of a standard guideline for the administration of focal therapy as a curative treatment for prostate cancer.
Background: Traditionally, EBRT prostate treatments have been administered using three different techniques: three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT). These radiation therapy treatment techniques are often combined with additional options focusing on treating systemic disease and the entire volume of the prostate. A novel approach to EBRT is currently in development, a localized treatment administered to only the primary disease within the prostate volume termed ‘Focal Therapy’.Methods/Design: The proposed research study is aimed to simulate 10 random EBRT prostate focal therapy treatments replicated within two treatment planning software; Monaco treatment planning system and Eclipse treatment planning system. All ten plans will be contoured simulations of focal therapy imaging sets replicated from authentic mpMRI anatomical images of focal therapy eligible prostate cancer patients. Following the completion of the 10 clinical plans, QA plans will be generated and administered via each products current commercial linacs; the TrueBeam and the Versa. All QA plans will have their radiation doses measured with Gafchromic EBT3 radiochromic film and analyzed using the gamma analysis index (γ).Discussion: To examine the uncertainties and limitations of an EBRT focal therapy prostate cancer treatment, it’s imperative that a large study replicating many clinical cases under varying conditions should be conducted. This allows the ability for the clinician to investigate errors and uncertainties at each stage of the treatment process prior to committing to a clinical study. The experimental results can also be used as a reference for the creation of a standard guideline for the administration of focal therapy as a curative treatment for prostate cancer.A comparison of planned radiotherapy dose distributions calculated by Monte Carlo with variation of technique, statistical uncertainty and voxel size on resulting gamma pass rateshttps://peerj.com/preprints/29042017-04-012017-04-01Kurt W Van Delinder
Background: The gamma analysis index (γ) is the most commonly used method to compare a calculated and measured dose distribution. A caveat to the clinical use of γ is that the formalism does have a sensitivity to noise present in either distribution. Monte Carlo (MC) based dose calculation methods are widely accepted as the most accurate method to calculate a resulting patient dose distribution from a radiation therapy treatment plan [6]. However, noise is inherently present as random errors or statistical uncertainty within all MC based dose calculation methods and is inversely proportional to the dose calculation time [7]. A research experiment performed by Van Delinder et al. investigated the effect of decreasing voxel size and increasing statistical uncertainty for a Monte Carlo based dose calculation method using 10 clinical head and neck (H&N) IMRT treatment plans. The experimental result was a definitive increase in γ passing rates with combined decrease in voxel size [10]. In order to further clinical information regarding this phenomenon, a large comprehensive study is required using multiple treatment techniques, a different treatment site, and using a different type of radiation measurement device.
Methods/Design: A study consisting of (ntotal = 30) thirty total prostate cancer radiation therapy plans comprised of (n1 = 10) ten VMAT plans, (n2 = 10) ten IMRT plans and (n3 = 10) ten 3DCRT plans. All treatment plans consisting of three different treatment techniques are to be delivered with a total dose of 79.2 Gy prescribed to the PTV at a rate of 1.8 Gy in 44 fractions. 3DCRT will be delivered using 6 fields, IMRT delivered as 7 fields and VMAT consists of 2 arcs (CCW from 1o to 359o with a collimator angle of 170o and CW from 359o to 1o with a collimator angle of 190o). All three treatment techniques will be calculated using 6 and 10 MV energy to allow an intra-study comparison between energies. All QA plans will then be calculated with varied statistical uncertainty from 0.5%, 1%, 2%, 3%, 4% and 5%. The voxel sizes will also be varied from 3mm, 2mm and 1mm for each of the statistical uncertainty percentages. All treatment plans will be measured using ArcCHECK radiation dose measurement device and the γ will be applied within SNC Machine. Both 3%/3mm and 2%/2mm will be implemented for γ criteria for all of the treatment plans.
Discussion: The necessity for a comprehensive research experiment investigating the effects of statistical uncertainty and voxel size amongst multiple treatment techniques with additional variations is required to guarantee safe quality assurance with routine use of Monte Carlo dose calculation methods. This experimental design acts as a contrasting research experiment when combined with prior literature allowing the clinician the ability to use the direct results and develop clinical recommendations for IMRT QA involving the use of Monte Carlo based dose calculations.
Background: The gamma analysis index (γ) is the most commonly used method to compare a calculated and measured dose distribution. A caveat to the clinical use of γ is that the formalism does have a sensitivity to noise present in either distribution. Monte Carlo (MC) based dose calculation methods are widely accepted as the most accurate method to calculate a resulting patient dose distribution from a radiation therapy treatment plan [6]. However, noise is inherently present as random errors or statistical uncertainty within all MC based dose calculation methods and is inversely proportional to the dose calculation time [7]. A research experiment performed by Van Delinder et al. investigated the effect of decreasing voxel size and increasing statistical uncertainty for a Monte Carlo based dose calculation method using 10 clinical head and neck (H&N) IMRT treatment plans. The experimental result was a definitive increase in γ passing rates with combined decrease in voxel size [10]. In order to further clinical information regarding this phenomenon, a large comprehensive study is required using multiple treatment techniques, a different treatment site, and using a different type of radiation measurement device.Methods/Design: A study consisting of (ntotal = 30) thirty total prostate cancer radiation therapy plans comprised of (n1 = 10) ten VMAT plans, (n2 = 10) ten IMRT plans and (n3 = 10) ten 3DCRT plans. All treatment plans consisting of three different treatment techniques are to be delivered with a total dose of 79.2 Gy prescribed to the PTV at a rate of 1.8 Gy in 44 fractions. 3DCRT will be delivered using 6 fields, IMRT delivered as 7 fields and VMAT consists of 2 arcs (CCW from 1o to 359o with a collimator angle of 170o and CW from 359o to1o with a collimator angle of 190o). All three treatment techniques will be calculated using 6 and 10 MV energy to allow an intra-study comparison between energies. All QA plans will then be calculated with varied statistical uncertainty from 0.5%, 1%, 2%, 3%, 4% and 5%. The voxel sizes will also be varied from 3mm, 2mm and 1mm for each of the statistical uncertainty percentages. All treatment plans will be measured using ArcCHECK radiation dose measurement device and the γ will be applied within SNC Machine. Both 3%/3mm and 2%/2mm will be implemented for γ criteria for all of the treatment plans.Discussion: The necessity for a comprehensive research experiment investigating the effects of statistical uncertainty and voxel size amongst multiple treatment techniques with additional variations is required to guarantee safe quality assurance with routine use of Monte Carlo dose calculation methods. This experimental design acts as a contrasting research experiment when combined with prior literature allowing the clinician the ability to use the direct results and develop clinical recommendations for IMRT QA involving the use of Monte Carlo based dose calculations.Sequential language learning versus language immersion in bilingualism: Diffusion MRI connectometry reveals microstructural evidencehttps://peerj.com/preprints/28532017-03-072017-03-07Razieh KhazaeiSoheila SobhaniFarzaneh RahmaniMohammad Hadi Aarabi
Background: Bilingualism is a universal phenomenon. Study of bilingual brain has provided evidence to probable advantageous outcomes of early second language learning and brain structural correlates to these outcomes. Preservation of cognitive function with aging and executive dexterity are amongst proposed benefits. Method: Using the data deposited by Pliatsikas we analyzed through diffusion MRI connectometry structural difference in white matter tracts in 20 healthy sequential bilingual adults, who used English as a second language on a daily basis, and 25 controls in fiber differentiation analyses. Significant tracts were extracted with and without regression against language immersion period. Results: Connectometry results revealed increased connectivity in corpus callosum (CC), bilateral cingulum, arcuate fasciculus (AF), and left Inferior fronto occipital fasciculus (IFOF), of sequential bilingual adults. Also bilateral IFOF, AF as well as body and genu of corpus callosum were positively correlated with language immersion time. Conclusion: Mentioned white matter tracts with diffusion structural significance in young adults with long immersion into the second language, confirm results of previous results. These are also in consort with known pathways involved in neurophysiological processes in speech stream and in cognitive performance. Insertion of immersion time as a variable in the model, yielded the same results with higher FDR values, except for arcuate fasciculus. Future studies are warranted to address structural differences with larger samples, investigating the effects of early language immersion on white matter tracts versus individual and social variables that interfere with white matter maturation and integrity.
Background: Bilingualism is a universal phenomenon. Study of bilingual brain has provided evidence to probable advantageous outcomes of early second language learning and brain structural correlates to these outcomes. Preservation of cognitive function with aging and executive dexterity are amongst proposed benefits. Method: Using the data deposited by Pliatsikas we analyzed through diffusion MRI connectometry structural difference in white matter tracts in 20 healthy sequential bilingual adults, who used English as a second language on a daily basis, and 25 controls in fiber differentiation analyses. Significant tracts were extracted with and without regression against language immersion period. Results: Connectometry results revealed increased connectivity in corpus callosum (CC), bilateral cingulum, arcuate fasciculus (AF), and left Inferior fronto occipital fasciculus (IFOF), of sequential bilingual adults. Also bilateral IFOF, AF as well as body and genu of corpus callosum were positively correlated with language immersion time. Conclusion: Mentioned white matter tracts with diffusion structural significance in young adults with long immersion into the second language, confirm results of previous results. These are also in consort with known pathways involved in neurophysiological processes in speech stream and in cognitive performance. Insertion of immersion time as a variable in the model, yielded the same results with higher FDR values, except for arcuate fasciculus. Future studies are warranted to address structural differences with larger samples, investigating the effects of early language immersion on white matter tracts versus individual and social variables that interfere with white matter maturation and integrity.