bluuebunny/crossref_metadata_2025_split huggingface dataset:
TH‐EF‐BRA‐10: High Spatiotemporal Resolution Self‐Sorted 4D MRI
Authors: Subashi E , Liu Y , Robertson S , Segars P , Driehuys B , Yin F , Cai J 
Published: July 2016

Purpose:To describe a novel method for self‐sorted 4D‐MRI and to characterize the output image quality as measured by signal‐to‐noise ratio (SNR), spatiotemporal resolution, and level of artifact.Methods:A three‐dimensional radial sampling function with a quasi‐random distribution of polar/azimuthal k‐space angles was implemented in a standard pulse sequence. Acquisition time was approximately 2 minutes. The DC component of the k‐space signal was used to estimate and sort the breathing cycle into ten respiratory phases. For a given respiratory phase, the k‐space data were combined with the periphery of the k‐space data from all phases and reconstructed with the re‐gridding algorithm onto a 1283 matrix. The extent of data sharing was controlled by the average breathing curve. The sampling and reconstruction technique were tested and validated in simulation, dynamic phantom, animal, and human studies with varying breathing periods/amplitudes.Results:The signal at the k‐space center accurately measures respiratory motion over a large range of breathing periods (0.5–7.0 seconds) and amplitudes (5–30% of FOV). Sharing of high frequency k‐space data driven by the average breathing curve improves spatial resolution and artifact level at a cost of an increase in noise floor. Although equal sharing of k‐space data improves resolution and SNR, phases with large temporal changes accumulate considerable distortion artifacts. In the absence of view‐sharing, no distortion artifacts are observed while spatial resolution is degraded.Conclusion:The use of a quasi‐random sampling function and view‐sharing driven by the average breathing curve provide a feasible method for self‐sorted 4D MRI at reduced acquisition times. This approach allows for the extent of data sharing to be inversely‐proportional to the average breathing motion hence improving resolution and decreasing artifact levels.NIH‐1R21CA165384
TH‐EF‐BRA‐11: Feasibility of Super‐Resolution Time‐Resolved 4DMRI for Multi‐Breath Volumetric Motion Simulation in Radiotherapy Planning
Authors: Li G , Wei J , Zakian K , Hunt M , Deasy J 
Published: July 2016

Purpose:To develop a novel super‐resolution time‐resolved 4DMRI technique to evaluate multi‐breath, irregular and complex organ motion without respiratory surrogate for radiotherapy planning.Methods:The super‐resolution time‐resolved (TR) 4DMRI approach combines a series of low‐resolution 3D cine MRI images acquired during free breathing (FB) with a high‐resolution breath‐hold (BH) 3DMRI via deformable image registration (DIR). Five volunteers participated in the study under an IRB‐approved protocol. The 3D cine images with voxel size of 5×5×5 mm3 at two volumes per second (2Hz) were acquired coronally using a T1 fast field echo sequence, half‐scan (0.8) acceleration, and SENSE (3) parallel imaging. Phase‐encoding was set in the lateral direction to minimize motion artifacts. The BH image with voxel size of 2×2×2 mm3 was acquired using the same sequence within 10 seconds. A demons‐based DIR program was employed to produce super‐resolution 2Hz 4DMRI. Registration quality was visually assessed using difference images between TR 4DMRI and 3D cine and quantitatively assessed using average voxel correlation. The fidelity of the 3D cine images was assessed using a gel phantom and a 1D motion platform by comparing mobile and static images.Results:Owing to voxel intensity similarity using the same MRI scanning sequence, accurate DIR between FB and BH images is achieved. The voxel correlations between 3D cine and TR 4DMRI are greater than 0.92 in all cases and the difference images illustrate minimal residual error with little systematic patterns. The 3D cine images of the mobile gel phantom preserve object geometry with minimal scanning artifacts.Conclusion:The super‐resolution time‐resolved 4DMRI technique has been achieved via DIR, providing a potential solution for multi‐breath motion assessment. Accurate DIR mapping has been achieved to map high‐resolution BH images to low‐resolution FB images, producing 2Hz volumetric high‐resolution 4DMRI. Further validation and improvement are still required prior to clinical applications.This study is in part supported by the NIH (U54CA137788/U54CA132378).
TH‐E‐202‐00: PET for Radiation Therapy
Authors: Lu Wei 
Published: July 2016

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss:

Pitfalls and remedies in PET/CT imaging for RT planning
The use of hypoxia PET imaging for radiotherapy
PET for tumor response evaluationThe first presentation will address the issue of mis‐registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image‐guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de‐escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi‐quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non‐FDG PET tracers for response assessment.

Learning Objectives:
Identify the causes of mis‐registration of CT and PET images in PET/CT, and review the strategies to remedy the issue.
Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo‐radiation therapy).
Understand the basics of dynamic PET imaging, compartmental modeling and parametric images.
Understand the basics of using FDG PET/CT for tumor response evaluation.
Learn about recent advancement in PET/CT radiomics and non‐FDG PET tracers for response assessment.This work was supported in part by the National Cancer Institute Grants R01CA172638.; W. Lu, This work was supported in part by the National Cancer Institute Grants R01CA172638.
TH‐E‐202‐03: PET for Tumor Response Evaluation
Authors: Lu W. 
Published: July 2016

PET/CT is a very important imaging tool in the management of oncology patients. PET/CT has been applied for treatment planning and response evaluation in radiation therapy. This educational session will discuss:

Pitfalls and remedies in PET/CT imaging for RT planning
The use of hypoxia PET imaging for radiotherapy
PET for tumor response evaluationThe first presentation will address the issue of mis‐registration between the CT and PET images in the thorax and the abdomen. We will discuss the challenges of respiratory gating and introduce an average CT technique to improve the registration for dose calculation and image‐guidance in radiation therapy. The second presentation will discuss the use of hypoxia PET Imaging for radiation therapy. We will discuss various hypoxia radiotracers, the choice of clinical acquisition protocol (in particular a single late static acquisition versus a dynamic acquisition), and the compartmental modeling with different transfer rate constants explained. We will demonstrate applications of hypoxia imaging for dose escalation/de‐escalation in clinical trials. The last presentation will discuss the use of PET/CT for tumor response evaluation. We will discuss anatomic response assessment vs. metabolic response assessment, visual evaluation and semi‐quantitative evaluation, and limitations of current PET/CT assessment. We will summarize clinical trials using PET response in guiding adaptive radiotherapy. Finally, we will summarize recent advancements in PET/CT radiomics and non‐FDG PET tracers for response assessment.

Learning Objectives:
Identify the causes of mis‐registration of CT and PET images in PET/CT, and review the strategies to remedy the issue.
Understand the basics of PET imaging of tumor hypoxia (radiotracers, how PET measures the hypoxia selective uptake, imaging protocols, applications in chemo‐radiation therapy).
Understand the basics of dynamic PET imaging, compartmental modeling and parametric images.
Understand the basics of using FDG PET/CT for tumor response evaluation.
Learn about recent advancement in PET/CT radiomics and non‐FDG PET tracers for response assessment.This work was supported in part by the National Cancer Institute Grants R01CA172638.; W. Lu, This work was supported in part by the National Cancer Institute Grants R01CA172638.
TH‐EF‐207A‐01: Respiratory Motion Correction in 4D‐Multi Pinhole Small Animal SPECT
Authors: Naseri M , Rajabi H , Wang J , Kalantari F 
Published: July 2016

Purpose:Respiration causes lesion smearing, image blurring and quality degradation, affecting lesion contrast and the ability to define correct lesion size. The spatial resolution of current multi pinhole SPECT (MPHS) scanners is sub‐millimeter. Therefore, the effect of motion is more noticeable in comparison to conventional SPECT scanner. Gated imaging aims to reduce motion artifacts. A major issue in gating is the lack of statistics and individual reconstructed frames are noisy. The increased noise in each frame, deteriorates the quantitative accuracy of the MPHS Images. The objective of this work, is to enhance the image quality in 4D‐MPHS imaging, by 4D image reconstruction.Methods:The new algorithm requires deformation vector fields (DVFs) that are calculated by non‐rigid Demons registration. The algorithm is based on the motion‐incorporated version of ordered subset expectation maximization (OSEM) algorithm. This iterative algorithm is capable to make full use of all projections to reconstruct each individual frame. To evaluate the performance of the proposed algorithm a simulation study was conducted. A fast ray tracing method was used to generate MPHS projections of a 4D digital mouse phantom with a small tumor in liver in eight different respiratory phases. To evaluate the 4D‐OSEM algorithm potential, tumor to liver activity ratio was compared with other image reconstruction methods including 3D‐MPHS and post reconstruction registered with Demons‐derived DVFs.Results:Image quality of 4D‐MPHS is greatly improved by the 4D‐OSEM algorithm. When all projections are used to reconstruct a 3D‐MPHS, motion blurring artifacts are present, leading to overestimation of the tumor size and 24% tumor contrast underestimation. This error reduced to 16% and 10% for post reconstruction registration methods and 4D‐OSEM respectively.Conclusion:4D‐OSEM method can be used for motion correction in 4D‐MPHS. The statistics and quantification are improved since all projection data are combined together to update the image.
TH‐EF‐207A‐07: An Integrated X‐Ray/bioluminescence Tomography System for Radiation Guidance and Tumor Evaluation
Authors: Shi J , Udayakumar T , Wang Z , Dogan N , Pollack A , Yang Y 
Published: July 2016

Purpose:CT is not able to differentiate tumors from surrounding soft tissue. This study is to develop a bioluminescence tomography (BLT) system that is integrated onto our previously developed CT guided small animal arc radiation treatment system (iSMAART) to guide radiation, monitor tumor growth and evaluate therapeutic response.Methods:The BLT system employs a CCD camera coupled with a high speed lens, and is aligned orthogonally to the x‐ray beam central axis. The two imaging modalities, CT and BLT, are physically registered through geometrical calibration. The CT anatomy provides an accurate contour of animal surface which is used to construct 3D mesh for BLT reconstruction. Bioluminescence projections are captured from multiple angles, once every 45 degree rotation. The diffusion equation based on analytical Kirchhoff approximation is adopted to model the photon propagation in tissues. A discrete cosine transform based reweighted L1‐norm regularization (DCT‐re‐L1) algorithm is used for BLT reconstruction. Experiments are conducted on a mouse orthotopic prostate tumor model (n=12) to evaluate the BLT performance, in terms of its robustness and accuracy in locating and quantifying the bioluminescent tumor cells. Iodinated contrast agent was injected intravenously to delineate the tumor in CT. The tumor location and volume obtained from CT also serve as a benchmark against BLT.Results:With our cutting edge reconstruction algorithm, BLT is able to accurately reconstruct the orthotopic prostate tumors. The tumor center of mass in BLT is within 0.5 mm radial distance of that in CT. The tumor volume in BLT is significantly correlated with that in CT (R2 = 0.81).Conclusion:The BLT can differentiate, localize and quantify tumors. Together with CT, BLT will provide precision radiation guidance and reliable treatment assessment in preclinical cancer research.
TH‐F‐201‐01: The Problem: Is This a Trick Question?
Authors: Bloch C. 
Published: July 2016

Multiple choice questions are a tool medical physicists encounter throughout their careers. They are a commonly used method of assessment during our early didactic training (graduate school, residency and board certification). They are used throughout our MOC process both in SAMs and online CE. And they are used for the MOC exam every 10 years. While we have significant training in answering these multiple choice questions, we rarely receive training in how to construct effective multiple choice questions. This is important too, as it is medical physicists who are creating the exams at academic institutions, for the AAPM SAMs and online CE as well as for the ABR exams (both initial and MOC). While there are rigorous scientific methods for evaluating the quality of questions in an exam that has been taken, creating good questions (stem) and multiple choice answers (distractors) requires skill and practice. This talk will cover some of the do's and don'ts for creating good multiple choice questions.Item analysis of answers to multiple choice questions can reveal a great deal about the quality of the questions. Questions can be measured in terms of their difficulty and ability to discriminate between examinees. The distractors themselves can be evaluated for their ability to discriminate as well. And finally the overall test can be evaluated for reliability. We will discuss some of the specifics of item analysis as well as provide guidelines for constructing good tests items.

Learning Objectives:
Understand rules for writing a good stem
Understand rules for writing good distractors
TH‐F‐201‐02: The Solution: The Science Behind Writing Good Questions
Authors: Richardson S. 
Published: July 2016

Multiple choice questions are a tool medical physicists encounter throughout their careers. They are a commonly used method of assessment during our early didactic training (graduate school, residency and board certification). They are used throughout our MOC process both in SAMs and online CE. And they are used for the MOC exam every 10 years. While we have significant training in answering these multiple choice questions, we rarely receive training in how to construct effective multiple choice questions. This is important too, as it is medical physicists who are creating the exams at academic institutions, for the AAPM SAMs and online CE as well as for the ABR exams (both initial and MOC). While there are rigorous scientific methods for evaluating the quality of questions in an exam that has been taken, creating good questions (stem) and multiple choice answers (distractors) requires skill and practice. This talk will cover some of the do's and don'ts for creating good multiple choice questions.Item analysis of answers to multiple choice questions can reveal a great deal about the quality of the questions. Questions can be measured in terms of their difficulty and ability to discriminate between examinees. The distractors themselves can be evaluated for their ability to discriminate as well. And finally the overall test can be evaluated for reliability. We will discuss some of the specifics of item analysis as well as provide guidelines for constructing good tests items.

Learning Objectives:
Understand rules for writing a good stem
Understand rules for writing good distractors
TH‐F‐202‐00: MRI for Radiation Therapy
Authors: Cai Jing 
Published: July 2016

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image‐guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy.

Learning Objectives:
To learn basics of MR physics and understand the differences between various pulse sequences
To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapyPartly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai
TH‐F‐202‐01: MRI Basics
Authors: Miller W. 
Published: July 2016

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image‐guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy.

Learning Objectives:
To learn basics of MR physics and understand the differences between various pulse sequences
To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapyPartly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai
Early prediction of typical outcome and mild developmental delay for prioritisation of service delivery for very preterm and very low birthweight infants: a study protocol
Authors: Caesar Rebecca , Boyd Roslyn N , Colditz Paul , Cioni Giovani , Ware Robert S , Salthouse Kaye , Doherty Julie , Jackson Maxine , Matthews Leanne , Hurley Tom , Morosini Anthony , Thomas Clare , Camadoo Laxmi , Baer Erica 
Published: July 2016

IntroductionOver 80% of very preterm (<32 weeks) and very low birthweight (<1500 g) infants will have either typical development (TD) or mild developmental delay (MDD) in multiple domains. As differentiation between TD and MDD can be difficult, infants with MDD often miss opportunities for intervention. For many clinicians, the ongoing challenge is early detection of MDD without over servicing the population. This study aims to: (1) identify early clinical biomarkers for use in this population to predict and differentiate between TD and MDD at 24 months corrected age. (2) Determine the extent to which family and caregiver factors will contribute to neurodevelopmental and behavioural outcomes.Methods and analysisParticipants will be a prospective cohort of 90 infants (<32 weeks and/or <1500 g). Between 34 weeks gestational age and 16 weeks post-term, infants will have a series of 5 neurological, neuromotor, neurobehavioural and perceptual assessments including General Movement Assessment at preterm, writhing and fidgety age. Primary caregivers will complete questionnaires to identify social risk, maternal depression and family strain. Extensive perinatal data will be collected from the medical record. At 24 months, corrected age (c.a) infants will be assessed using standardised tools including the Bayley Scales of Infant and Toddler Development—Third Edition (Bayley III). Longitudinal trajectories of early assessment findings will be examined to determine any predictive relationship with motor and cognitive outcomes at 24 months c.a. Published data of a cohort of Australian children assessed with the Bayley III at 24 months c.a will provide a reference group of term-born controls.EthicsEthical approval has been obtained from the Queensland Children's Health Services Human Research Ethics Committee (HREC/13/QRCH/66), the University of Queensland (2013001019) and the Sunshine Coast Hospital and Health Service, SC-Research Governance (SSA/13/QNB/66). Publication of all study outcomes will be in peer-reviewed journals.Trial registration numberACTRN12614000480684; Pre-results.
Diagnosis and mortality in prehospital emergency patients transported to hospital: a population-based and registry-based cohort study
Authors: Christensen Erika Frischknecht , Larsen Thomas Mulvad , Jensen Flemming Bøgh , Bendtsen Mette Dahl , Hansen Poul Anders , Johnsen Søren Paaske , Christiansen Christian Fynbo 
Published: July 2016

ObjectiveKnowledge about patients after calling for an ambulance is limited to subgroups, such as patients with cardiac arrest, myocardial infarction, trauma and stroke, while population-based studies including all diagnoses are few. We examined the diagnostic pattern and mortality among all patients brought to hospital by ambulance after emergency calls.DesignRegistry-based cohort study.Setting and participantsWe included patients brought to hospital in an ambulance dispatched after emergency calls during 2007–2014 in the North Denmark Region (580 000 inhabitants). We reported hospital diagnosis according to the chapters of the International Classification of Diseases, 10th Edition (ICD-10), and studied death on days 1 and 30 after the call. Cohort characteristics and diagnoses were described, and the Kaplan-Meier method was used to estimate mortality and 95% CIs.ResultsIn total, 148 757 patients were included, mean age 52.9 (SD 24.3) years. The most frequent ICD-10 diagnosis chapters were: ‘injury and poisoning’ (30.0%), and the 2 non-specific diagnosis chapters: ‘symptoms and abnormal findings, not elsewhere classified’ (17.5%) and ‘factors influencing health status and contact with health services’ (14.1%), followed by ‘diseases of the circulatory system’ (10.6%) and ‘diseases of the respiratory system’ (6.7%). The overall 1-day mortality was 1.8% (CI 1.7% to 1.8%) and 30-day mortality 4.7% (CI 4.6% to 4.8%). ‘Diseases of the circulatory system’ had the highest 1-day mortality of 7.7% (CI 7.3% to 8.1%) accounting for 1209 deaths. After 30 days, the highest number of deaths were among circulatory diseases (2313), respiratory diseases (1148), ‘symptoms and abnormal findings, not elsewhere classified’ (1119) and ‘injury and poisoning’ (741), and 30 days mortality in percentage was 14.7%, 11.6%, 4.3% and 1.7%, respectively.ConclusionsPatients' diagnoses from hospital stay after calling 1-1-2 in this population-based study were distributed across all ICD-10 chapters. Mortality varied widely between diagnostic groups. Non-specific diagnoses accounted for one-third of the patients and contributed to mortality in terms of total number of deaths.