Fast MRI Research Articles

A fast chemical exchange saturation transfer imaging scheme based on single-shot spatiotemporal encoding.

To design a new approach that can not only keep the spatial and temporal resolution but also have better built-in immunity to magnetic field inhomogeneity and chemical shift effects than the single-shot echo planar imaging (EPI) for chemical exchange saturation transfer (CEST) MRI. The single-shot spatiotemporally encoded (SPEN) MRI sequence was combined with a continuous wave saturation pulse for fast CEST MRI (CEST-SPEN MRI). The resulting images were super-resolved reconstructed by a hybrid method that solves the l1 norm minimization together with total variation (TV) regularization. Partial Lorentzian fitting was used to analyze the subsequent Z-spectra. Experimental results of a creatine phantom and in vivo tumor rat brains show that CEST-SPEN MRI has good capability in providing CEST-based and NOE-based contrast images. Compared with CEST-EPI, CEST-SPEN MRI has better immunity to magnetic field inhomogeneity and provides better contrast images within identical acquisition time, especially under an identical inhomogeneous field. Magn Reson Med 77:1786-1796, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

High resolution imaging of the intracranial vessel wall at 3 and 7T using 3D fast spin echo MRI.

High resolution MRI of the intracranial vessel wall provides important insights in the assessment of intracranial vascular disease. This study aims to refine high resolution 3D MRI techniques for intracranial vessel wall imaging at both 3 and 7T using customized flip angle train design, and to explore their comparative abilities. 11 patients with intracranial artery disease (four atherosclerotic plaques, six aneurysms and one reversible cerebral vasoconstriction syndrome) were imaged at 3 and 7T with a 3D T 1-weighted fast-spin-echo sequence (SPACE) both pre and post Gd contrast injection. Wall to lumen contrast ratio (CRwall-lumen), contrast enhancement ratio (ER) and the sharpness of the vessel wall were quantified. Two experienced radiologists evaluated the image quality on a 0-5 scale. Both 3 and 7T achieved good image quality with high resolution (nominal 0.5mm isotropic) and whole brain coverage. The CRwall-lumen and the ER measurements were comparable (p>0.05). The 7T images were significantly sharper (sharpness: 2.69±0.50 vs. 1.88±0.53mm(-1), p<0.001) with higher image quality (reader 1 score: 3.5±1.1 vs. 2.4±1.1, p=0.002) compared to 3T. 3D T 1-weighted SPACE can be used for intracranial vessel wall evaluation at both 3 and 7T. 7T provides significantly better image quality and improves the confidence of diagnosis.

A fast and flexible MRI system for the study of dynamic vocal tract shaping.

The aim of this work was to develop and evaluate an MRI-based system for study of dynamic vocal tract shaping during speech production, which provides high spatial and temporal resolution. The proposed system utilizes (a) custom eight-channel upper airway coils that have high sensitivity to upper airway regions of interest, (b) two-dimensional golden angle spiral gradient echo acquisition, (c) on-the-fly view-sharing reconstruction, and (d) off-line temporal finite difference constrained reconstruction. The system also provides simultaneous noise-cancelled and temporally aligned audio. The system is evaluated in 3 healthy volunteers, and 1 tongue cancer patient, with a broad range of speech tasks. We report spatiotemporal resolutions of 2.4 × 2.4 mm2 every 12 ms for single-slice imaging, and 2.4 × 2.4 mm2 every 36 ms for three-slice imaging, which reflects roughly 7-fold acceleration over Nyquist sampling. This system demonstrates improved temporal fidelity in capturing rapid vocal tract shaping for tasks, such as producing consonant clusters in speech, and beat-boxing sounds. Novel acoustic-articulatory analysis was also demonstrated. A synergistic combination of custom coils, spiral acquisitions, and constrained reconstruction enables visualization of rapid speech with high spatiotemporal resolution in multiple planes. Magn Reson Med 77:112-125, 2017. © 2016 Wiley Periodicals, Inc.

High Frequency of Normal Response during GH Stimulation Tests in Patients with Ectopic Posterior Pituitary Gland: A Source of False-Negative Diagnosis of Pituitary Insufficiency

Aims: To report false-negative normal growth hormone (GH) peak response in patients with ectopic posterior pituitary gland (EPP) identified with a simplified magnetic resonance imaging (FAST1-MRI). Methods: We analyzed 75 EPP patients with short stature and reduced growth velocity. Sagittal-T1 imaging (thickness: 2 mm and gap: 0.2 mm) without gadolinium administration was used. A GH peak of ≥5 ng/ml after clonidine or insulin stimulation was considered normal. Results: Normal GH response was observed in 15 of 75 (20%) patients [mean (SDS) peak = 8.2 (4.1) ng/ml]. Age at diagnosis [6.5 (3.0) years vs. 7.8 (4.1) years], gender (10 males/5 females vs. 44 males/16 females), pubertal stage (14 prepubertal/1 pubertal vs. 51 prepubertal/7 pubertal), and target height [-0.4 (0.6) vs. -0.4 (0.9)] were recorded. The perinatal history did not differ between responsive and nonresponsive patients. There was a trend to more frequent multiple hormone deficiency in nonresponsive when compared with responsive patients [3/15 (20%) and 31/60 (51.7%), respectively (p = 0.055)]. Height at diagnosis was lower in nonresponsive patients (p = 0.042). No significant difference in the IGF1 levels (p = 0.598) was observed between the groups. Conclusion: Normal GH values after stimulation tests do not exclude EPP-associated GH deficiency. A simplified fast acquisition sagittal-T1 MRI protocol investigation included at the initial diagnostic approach is able to prevent misdiagnosis of GH deficiency in patients with short stature.

Inter-observer agreement of MRI-based tumor delineation for preoperative radiotherapy boost in locally advanced rectal cancer

BackgroundWhile surgery remains the cornerstone of rectal cancer treatment, organ-preservation is upcoming. Therefore, neo-adjuvant treatment should be optimized. By escalating doses, response can be increased. To limit toxicity of boost, accurate gross tumor volume (GTV) definition is required. MRI, especially undeformed fast spin echo diffusion-weighted MRI (DWI), looks promising for delineation. However, inconsistencies between observers should be quantified before clinical implementation. We aim to find which MRI sequence (T2w, DWI or combination) is optimal and clinically useful for GTV definition by evaluating inter-observer agreement. MethodsLocally advanced rectal cancer patients (tumors <10cm from anal verge) were scanned on 3T MRI transverse T2w and DWI (b=800s/mm2). Three independent observers delineated T2w, DWI and combination (Combi) after training-set. Volumes, conformity index (CI), and maximum Hausdorff distance (HD) were calculated between any observer-pair per patient per modality. ResultsTwenty-four consecutive patients were included. One patient had cT2 (4.2%), 19 cT3 (79.1%) and 4 cT4 (16.7%), with 2 clinical node negative (8.3%), 4 cN1 (16.7%), and 18 cN2 (75.0%) on MRI. From 24 patients, 70 sequences were available (24x T2, 23x DWI, and 23x Combi). Between observers, no significant volume differences were observed per modality. T2 showed significantly largest volumes compared to DWI (mean difference 19.85ml, SD 17.42, p<0.0001) and Combi (mean difference 7.16ml, SD 11.58, p<0.0001). Mean CI was 0.70, 0.71 and 0.69 for T2, DWI and Combi respectively (p>0.61). Average HD was largest on T2 (18.60mm, max 31.40mm, min 9.20mm). DiscussionDelineation on DWI resulted in delineation of the smallest volumes with similar consistency and mean distances, but with slightly lower Hausdorff distances compared to T2 and Combi. However, with lack of a gold standard it remains difficult to establish if delineations also represent true tumor. Study strengths were DWI adaptation to exclude geometrical distortions and training-set. DWI shows great potential for delineation purposes as long as sufficient experience exists and geometrical distortions are eliminated.

Incidence of Retrocochlear Pathology Found on MRI in Patients With Non-Pulsatile Tinnitus

To identify the incidence of retrocochlear pathology on MRI in patients with non-pulsatile tinnitus. Retrospective review. Tertiary referral center. Adults with MRIs performed between March 1, 2008 and February 1, 2014 for non-pulsatile tinnitus with or without hearing loss. MRI. Incidence of retrocochlear pathology. Of the 218 patients who met inclusion criteria, 198 (91.3%) had unremarkable MRIs. Six patients (2.7%) had MRI findings that accounted for their tinnitus. Of these patients, five had unilateral tinnitus with asymmetric hearing loss because of acoustic neuroma found on MRI. One patient presented with bilateral tinnitus with asymmetric hearing loss and was found to have a right acoustic neuroma. Twenty (9.2%) patients had bilateral or unilateral tinnitus without hearing loss, all with unremarkable MRIs. Fourteen patients (6.4%) had incidental findings including two acoustic neuromas that were identified contralateral to the side of presenting tinnitus. Imaging should be used judiciously in the evaluation of tinnitus. Patients with unilateral tinnitus and asymmetric hearing loss were most likely to have abnormal findings. The majority of MRIs performed for tinnitus were normal in our study. Given the low incidence of MRI findings in the workup of tinnitus, every effort should be made to optimize screening protocols. Noncontrasted fast spin-echo T2-weighted MRI should be used to assess patients with tinnitus when there is low suspicion for retrocochlear pathology. Patients with unilateral non-pulsatile tinnitus with symmetric hearing may be observed, but clinical judgement should determine the need for further imaging.

Visualization of perivascular spaces in the human brain at 7 T: sequence optimization and morphology characterization

Noninvasive imaging of perivascular spaces (PVSs) may provide useful insights into their role in normal brain physiology and diseases. Fast MRI sequences with sub-millimeter spatial resolutions and high contrast-to-noise ratio (CNR) are required for accurate delineation of PVS in human. To achieve the optimal condition for PVS imaging at 7T, we carried out detailed simulation and experimental studies to characterize the dependence of CNR on imaging sequences (T1 versus T2-weighted) and sequence parameters. In addition, PVSs were segmented semi-automatically, which revealed much larger numbers of PVSs in young healthy subjects (age 21–37years) than previously reported. To the best of our knowledge, our study provides, for the first time, detailed length, volume, and diameter distributions of PVS in the white matter and subcortical nuclei, which can serve as a reference for future studies of PVS abnormalities under diseased conditions.

Quantification of lung tumor rotation with automated landmark extraction using orthogonal cine MRI images

The quantification of tumor motion in sites affected by respiratory motion is of primary importance to improve treatment accuracy. To account for motion, different studies analyzed the translational component only, without focusing on the rotational component, which was quantified in a few studies on the prostate with implanted markers. The aim of our study was to propose a tool able to quantify lung tumor rotation without the use of internal markers, thus providing accurate motion detection close to critical structures such as the heart or liver. Specifically, we propose the use of an automatic feature extraction method in combination with the acquisition of fast orthogonal cine MRI images of nine lung patients. As a preliminary test, we evaluated the performance of the feature extraction method by applying it on regions of interest around (i) the diaphragm and (ii) the tumor and comparing the estimated motion with that obtained by (i) the extraction of the diaphragm profile and (ii) the segmentation of the tumor, respectively. The results confirmed the capability of the proposed method in quantifying tumor motion. Then, a point-based rigid registration was applied to the extracted tumor features between all frames to account for rotation. The median lung rotation values were −0.6 ± 2.3° and −1.5 ± 2.7° in the sagittal and coronal planes respectively, confirming the need to account for tumor rotation along with translation to improve radiotherapy treatment.

Dynamics of respiratory and cardiac CSF motion revealed with real-time simultaneous multi-slice EPI velocity phase contrast imaging

Cerebrospinal fluid (CSF) dynamics have been mostly studied with cardiac-gated phase contrast MRI combining signal from many cardiac cycles to create cine-phase sampling of one time-averaged cardiac cycle. The relative effects of cardiac and respiratory changes on CSF movement are not well understood. There is possible respiration-driven movement of CSF in ventricles, cisterns, and subarachnoid spaces which has not been characterized with velocity measurements. To date, commonly used cine-phase contrast techniques of velocity imaging inherently cannot detect respiratory velocity changes since cardiac-gated data acquired over several minutes randomizes respiratory phase contributions. We have developed an extremely fast, real-time, and quantitative MRI technique to image CSF velocity in simultaneous multi-slice (SMS) echo planar imaging (EPI) acquisitions of 3 or 6 slice levels simultaneously over 30s and observe 3D spatial distributions of CSF velocity. Measurements were made in 10 subjects utilizing a respiratory belt to record respiratory phases and visual cues to instruct subjects on breathing rates. A protocol is able to measure velocity within regions of brain and basal cisterns covered with 24 axial slices in 4minutes, repeated for 3 velocity directions. These measurements were performed throughout the whole brain, rather than in selected line regions so that a global view of CSF dynamics could be visualized. Observations of cardiac and breathing-driven CSF dynamics show bidirectional respiratory motion occurs primarily along the central axis through the basal cisterns and intraventricular passageways and to a lesser extent in the peripheral Sylvian fissure with little CSF motion present in subarachnoid spaces. During inspiration phase, there is upward (inferior to superior) CSF movement into the cranial cavity and lateral ventricles and a reversal of direction in expiration phase.

Minimum mutual information based level set clustering algorithm for fast MRI tissue segmentation.

Accurate and accelerated MRI tissue recognition is a crucial preprocessing for real-time 3d tissue modeling and medical diagnosis. This paper proposed an information de-correlated clustering algorithm implemented by variational level set method for fast tissue segmentation. The key idea is to design a local correlation term between original image and piecewise constant into the variational framework. The minimized correlation will then lead to de-correlated piecewise regions. Firstly, by introducing a continuous bounded variational domain describing the image, a probabilistic image restoration model is assumed to modify the distortion. Secondly, regional mutual information is introduced to measure the correlation between piecewise regions and original images. As a de-correlated description of the image, piecewise constants are finally solved by numerical approximation and level set evolution. The converged piecewise constants automatically clusters image domain into discriminative regions. The segmentation results show that our algorithm performs well in terms of time consuming, accuracy, convergence and clustering capability.

Fast reference based MRI.

In many clinical MRI scenarios, existing imaging information can be used to significantly shorten acquisition time or improve Signal to Noise Ratio (SNR). In those cases, a previously acquired image can serve as a reference image, that may exhibit similarity in some sense to the image being acquired. Examples include similarity between adjacent slices in high resolution MRI, similarity between various contrasts in the same scans and similarity between different scans of the same patients. In this paper we present a general framework for utilizing reference images for fast MRI. We take into account that the reference image may exhibit low similarity with the acquired image and develop a hybrid adaptive-weighted approach for sampling and reconstruction. Experiments demonstrate the performance of the method in three different clinical MRI scenarios: SNR improvement in high resolution brain MRI, utilizing similarity between T2-weighted and fluid-attenuated inversion recovery (FLAIR) for fast FLAIR scanning and utilizing similarity between baseline and follow-up scans for fast follow-up scanning.

Exponential Wavelet Iterative Shrinkage Thresholding Algorithm for compressed sensing magnetic resonance imaging

It is beneficial for both hospitals and patients to accelerate MRI scanning. Recently, a new fast MRI technique based on CS was proposed. However, the reconstruction quality and computation time of CS-MRI did not meet the standard of clinical use. Therefore, we proposed a novel algorithm based on three successful components: the sparsity of EWT, the rapidness of FISTA, and the excellent tuning in SISTA. The proposed method was dubbed Exponential Wavelet Iterative Shrinkage/Threshold Algorithm (EWISTA). Experiments over four kinds of MR images (brain, ankle, knee, and ADHD) indicated that the proposed EWISTA showed better reconstruction performance than the state-of-the-art algorithms such as FCSA, ISTA, FISTA, SISTA, and EWT–ISTA. Moreover, EWISTA was faster than ISTA and EWT–ISTA, but slightly slower than FCSA, FISTA and SISTA.

WE-EF-BRD-01: Past, Present and Future: MRI-Guided Radiotherapy From 2005 to 2025

MRI-guided treatment is a growing area of medicine, particularly in radiotherapy and surgery. The exquisite soft tissue anatomic contrast offered by MRI, along with functional imaging, makes the use of MRI during therapeutic procedures very attractive. Challenging the utility of MRI in the therapy room are many issues including the physics of MRI and the impact on the environment and therapeutic instruments, the impact of the room and instruments on the MRI; safety, space, design and cost. In this session, the applications and challenges of MRI-guided treatment will be described. The session format is: 1. Past, present and future: MRI-guided radiotherapy from 2005 to 2025: Jan Lagendijk 2. Battling Maxwell’s equations: Physics challenges and solutions for hybrid MRI systems: Paul Keall 3. I want it now!: Advances in MRI acquisition, reconstruction and the use of priors to enable fast anatomic and physiologic imaging to inform guidance and adaptation decisions: Yanle Hu 4. MR in the OR: The growth and applications of MRI for interventional radiology and surgery: Rebecca Fahrig Learning Objectives: 1. To understand the history and trajectory of MRI-guided radiotherapy 2. To understand the challenges of integrating MR imaging systems with linear accelerators 3. To understand the latest in fast MRI methods to enable the visualisation of anatomy and physiology on radiotherapy treatment timescales 4. To understand the growing role and challenges of MRI for image-guided surgical procedures My disclosures are publicly available and updated at: http://sydney.edu.au/medicine/radiation-physics/about-us/disclosures.php

WE-B-BRD-01: MR-LINAC

The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptive QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: 1. Understand the difference between a standard and a radiotherapy-specific MRI QA program. 2. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. 3. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. 4. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). 5. Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.

WE-B-BRD-02: MR Simulation for Radiation Therapy

The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptive QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: 1. Understand the difference between a standard and a radiotherapy-specific MRI QA program. 2. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. 3. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. 4. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). 5. Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.

WE-B-BRD-03: MR QA/QC for MRgRT

The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptive QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: 1. Understand the difference between a standard and a radiotherapy-specific MRI QA program. 2. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. 3. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. 4. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). 5. Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.

WE-B-BRD-00: MRI for Radiation Oncology

The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptive QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: 1. Understand the difference between a standard and a radiotherapy-specific MRI QA program. 2. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. 3. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. 4. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). 5. Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.

WE-EF-BRD-00: New Developments in Hybrid MR-Treatment: Applications

MRI-guided treatment is a growing area of medicine, particularly in radiotherapy and surgery. The exquisite soft tissue anatomic contrast offered by MRI, along with functional imaging, makes the use of MRI during therapeutic procedures very attractive. Challenging the utility of MRI in the therapy room are many issues including the physics of MRI and the impact on the environment and therapeutic instruments, the impact of the room and instruments on the MRI; safety, space, design and cost. In this session, the applications and challenges of MRI-guided treatment will be described. The session format is: 1. Past, present and future: MRI-guided radiotherapy from 2005 to 2025: Jan Lagendijk 2. Battling Maxwell’s equations: Physics challenges and solutions for hybrid MRI systems: Paul Keall 3. I want it now!: Advances in MRI acquisition, reconstruction and the use of priors to enable fast anatomic and physiologic imaging to inform guidance and adaptation decisions: Yanle Hu 4. MR in the OR: The growth and applications of MRI for interventional radiology and surgery: Rebecca Fahrig Learning Objectives: 1. To understand the history and trajectory of MRI-guided radiotherapy 2. To understand the challenges of integrating MR imaging systems with linear accelerators 3. To understand the latest in fast MRI methods to enable the visualisation of anatomy and physiology on radiotherapy treatment timescales 4. To understand the growing role and challenges of MRI for image-guided surgical procedures My disclosures are publicly available and updated at: http://sydney.edu.au/medicine/radiation-physics/about-us/disclosures.php

WE-EF-BRD-04: MR in the OR: The Growth and Applications of MRI for Interventional Radiology and Surgery

MRI-guided treatment is a growing area of medicine, particularly in radiotherapy and surgery. The exquisite soft tissue anatomic contrast offered by MRI, along with functional imaging, makes the use of MRI during therapeutic procedures very attractive. Challenging the utility of MRI in the therapy room are many issues including the physics of MRI and the impact on the environment and therapeutic instruments, the impact of the room and instruments on the MRI; safety, space, design and cost. In this session, the applications and challenges of MRI-guided treatment will be described. The session format is: 1. Past, present and future: MRI-guided radiotherapy from 2005 to 2025: Jan Lagendijk 2. Battling Maxwell’s equations: Physics challenges and solutions for hybrid MRI systems: Paul Keall 3. I want it now!: Advances in MRI acquisition, reconstruction and the use of priors to enable fast anatomic and physiologic imaging to inform guidance and adaptation decisions: Yanle Hu 4. MR in the OR: The growth and applications of MRI for interventional radiology and surgery: Rebecca Fahrig Learning Objectives: 1. To understand the history and trajectory of MRI-guided radiotherapy 2. To understand the challenges of integrating MR imaging systems with linear accelerators 3. To understand the latest in fast MRI methods to enable the visualisation of anatomy and physiology on radiotherapy treatment timescales 4. To understand the growing role and challenges of MRI for image-guided surgical procedures My disclosures are publicly available and updated at: http://sydney.edu.au/medicine/radiation-physics/about-us/disclosures.php

WE-EF-BRD-03: I Want It Now!: Advances in MRI Acquisition, Reconstruction and the Use of Priors to Enable Fast Anatomic and Physiologic Imaging to Inform Guidance and Adaptation Decisions

MRI-guided treatment is a growing area of medicine, particularly in radiotherapy and surgery. The exquisite soft tissue anatomic contrast offered by MRI, along with functional imaging, makes the use of MRI during therapeutic procedures very attractive. Challenging the utility of MRI in the therapy room are many issues including the physics of MRI and the impact on the environment and therapeutic instruments, the impact of the room and instruments on the MRI; safety, space, design and cost. In this session, the applications and challenges of MRI-guided treatment will be described. The session format is: 1. Past, present and future: MRI-guided radiotherapy from 2005 to 2025: Jan Lagendijk 2. Battling Maxwell’s equations: Physics challenges and solutions for hybrid MRI systems: Paul Keall 3. I want it now!: Advances in MRI acquisition, reconstruction and the use of priors to enable fast anatomic and physiologic imaging to inform guidance and adaptation decisions: Yanle Hu 4. MR in the OR: The growth and applications of MRI for interventional radiology and surgery: Rebecca Fahrig Learning Objectives: 1. To understand the history and trajectory of MRI-guided radiotherapy 2. To understand the challenges of integrating MR imaging systems with linear accelerators 3. To understand the latest in fast MRI methods to enable the visualisation of anatomy and physiology on radiotherapy treatment timescales 4. To understand the growing role and challenges of MRI for image-guided surgical procedures My disclosures are publicly available and updated at: http://sydney.edu.au/medicine/radiation-physics/about-us/disclosures.php