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Su H, Kwok KW, Cleary K, Iordachita I, Cavusoglu MC, Desai JP, Fischer GS. State of the Art and Future Opportunities in MRI-Guided Robot-Assisted Surgery and Interventions. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2022; 110:968-992. [PMID: 35756185 PMCID: PMC9231642 DOI: 10.1109/jproc.2022.3169146] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Magnetic resonance imaging (MRI) can provide high-quality 3-D visualization of target anatomy, surrounding tissue, and instrumentation, but there are significant challenges in harnessing it for effectively guiding interventional procedures. Challenges include the strong static magnetic field, rapidly switching magnetic field gradients, high-power radio frequency pulses, sensitivity to electrical noise, and constrained space to operate within the bore of the scanner. MRI has a number of advantages over other medical imaging modalities, including no ionizing radiation, excellent soft-tissue contrast that allows for visualization of tumors and other features that are not readily visible by other modalities, true 3-D imaging capabilities, including the ability to image arbitrary scan plane geometry or perform volumetric imaging, and capability for multimodality sensing, including diffusion, dynamic contrast, blood flow, blood oxygenation, temperature, and tracking of biomarkers. The use of robotic assistants within the MRI bore, alongside the patient during imaging, enables intraoperative MR imaging (iMRI) to guide a surgical intervention in a closed-loop fashion that can include tracking of tissue deformation and target motion, localization of instrumentation, and monitoring of therapy delivery. With the ever-expanding clinical use of MRI, MRI-compatible robotic systems have been heralded as a new approach to assist interventional procedures to allow physicians to treat patients more accurately and effectively. Deploying robotic systems inside the bore synergizes the visual capability of MRI and the manipulation capability of robotic assistance, resulting in a closed-loop surgery architecture. This article details the challenges and history of robotic systems intended to operate in an MRI environment and outlines promising clinical applications and associated state-of-the-art MRI-compatible robotic systems and technology for making this possible.
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Affiliation(s)
- Hao Su
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 USA
| | - Ka-Wai Kwok
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong
| | - Kevin Cleary
- Children's National Health System, Washington, DC 20010 USA
| | - Iulian Iordachita
- Laboratory for Computational Sensing and Robotics (LCSR), Johns Hopkins University, Baltimore, MD 21218 USA
| | - M Cenk Cavusoglu
- Department of Electrical, Computer, and Systems Engineering, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Jaydev P Desai
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 USA
| | - Gregory S Fischer
- Department of Robotics Engineering, Worcester Polytechnic Institute, Worcester, MA 01609 USA
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Bydder M, Carl M, Bydder GM, Du J. MRI chemical shift artifact produced by center-out radial sampling of k-space: a potential pitfall in clinical diagnosis. Quant Imaging Med Surg 2021; 11:3677-3683. [PMID: 34341741 DOI: 10.21037/qims-21-115] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/22/2021] [Indexed: 11/06/2022]
Abstract
Background Center-out radial sampling of k-space in magnetic resonance imaging employs a different direction for each readout. Off-resonance artifacts (including those produced by chemical shift between water and fat) found with this type of sampling are usually described as blurring, however more specific characterization of these artifacts can be ascertained from the fact that their point spread function is ring-shaped. This produces effects that differ from those seen with Cartesian sampling of k-space. Experiments were designed to demonstrate the origin of these artifacts and a volunteer was imaged to show them. Methods Two phantoms containing oil in a syringe and an annulus of oil surrounded by water were scanned with a range of bandwidths from 62.5 down to 4 kHz. In a human volunteer, head, pelvis and spine images were obtained with bandwidths of 62.5 and 4 kHz. Results The two phantoms showed displacement of the oil signal away from the center into the region of the surrounding water. The effect increased as the bandwidth was decreased. In the head of the volunteer, signal from fat in red bone marrow in the skull was displaced centrally and peripherally relative to water within the marrow, and appeared in the region between the skull and the brain, as well as in the surrounding scalp. Displacements of the former type simulated subdural hematomas. Displacement of perivesical fat signal centrally over the wall of the bladder simulated bladder tumor, and displacement of fat signal from red bone marrow in the lumbar spine to the intervertebral discs simulated their cartilaginous endplates. Conclusions Center-out radial artifacts are important to recognize on clinical images since they may mimic anatomy and simulate pathology. The article shows how these artifacts originate, includes examples, and describes how the artifacts differ from Cartesian chemical shift artifacts.
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Affiliation(s)
- Mark Bydder
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, CA, USA
| | - Michael Carl
- Global MR Application and Workflow, GE Healthcare, San Diego, CA, USA
| | - Graeme M Bydder
- Department of Radiology, University of California San Diego, San Diego, CA, USA.,Department of Radiology, The Christie NHS Foundation Trust, Manchester, UK
| | - Jiang Du
- Department of Radiology, University of California San Diego, San Diego, CA, USA
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Shcherbakova Y, Bartels LW, Mandija S, Beld E, Seevinck PR, van der Voort van Zyp JRN, Kerkmeijer LGW, Moonen CTW, Lagendijk JJW, van den Berg CAT. Visualization of gold fiducial markers in the prostate using phase-cycled bSSFP imaging for MRI-only radiotherapy. ACTA ACUST UNITED AC 2019; 64:185001. [DOI: 10.1088/1361-6560/ab35c3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Beld E, Moerland MA, van der Voort van Zyp JRN, Viergever MA, Lagendijk JJW, Seevinck PR. MRI artifact simulation for clinically relevant MRI sequences for guidance of prostate HDR brachytherapy. Phys Med Biol 2019; 64:095006. [PMID: 30947159 DOI: 10.1088/1361-6560/ab15ed] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For the purpose of magnetic resonance imaging (MRI) guidance of prostate high-dose-rate (HDR) brachytherapy, this paper presents a study on the potential of clinically relevant MRI sequences to facilitate tracking or localization of brachytherapy devices (HDR source/titanium needle), and which could simultaneously be used to visualize the anatomy. The tracking or localization involves simulation of the MRI artifact in combination with a template matching algorithm. Simulations of the MRI artifacts induced by an HDR brachytherapy source and a titanium needle were implemented for four types of sequences: spoiled gradient echo, spin echo, balanced steady-state free precession (bSSFP) and bSSFP with spectral attenuated inversion recovery (SPAIR) fat suppression. A phantom study was conducted in which mentioned sequences (in 2D) as well as the volumetric MRI sequences of the current clinical scan protocol were applied to obtain the induced MRI artifacts for an HDR source and a titanium needle. Localization of the objects was performed by a phase correlation based template matching algorithm. The simulated images demonstrated high correspondences with the acquired MR images, and allowed localization of the objects. A comparison between the object positions obtained for all applied MRI sequences showed deviations (from the average position) of 0.2-0.3 mm, proving that all MRI sequences were suitable for localization of the objects, irrespective of their 2D or volumetric nature. This study demonstrated that the MRI artifact induced by an HDR source or a titanium needle could be simulated for the four investigated types of MRI sequences (spoiled gradient echo, spin echo, bSSFP and bSSFP-SPAIR), valuable for real-time object localization in clinical practice. This leads to more flexibility in the choice of MRI sequences for guidance of HDR brachytherapy, as they are suitable for both object localization and anatomy visualization.
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Affiliation(s)
- Ellis Beld
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands. Author to whom correspondence may be addressed
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Vafay Eslahi S, Ji J. Accelerated positive contrast MRI of interventional devices using parallel compressed sensing imaging. Magn Reson Imaging 2019; 60:130-136. [PMID: 31028791 DOI: 10.1016/j.mri.2019.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/04/2019] [Accepted: 04/06/2019] [Indexed: 11/24/2022]
Abstract
Susceptibility-based magnetic resonance imaging (MRI) method can image small MR-compatible devices with positive contrast. However, the relatively long data acquisition time required by the method hinders its practical applications. This study presents a parallel compressive sensing technique with a modified fast spin echo to accelerate data acquisition for the susceptibility-based positive contrast MRI. The method integrates the generalized autocalibrating partially parallel acquisitions and the compressive sensing techniques in the reconstruction algorithm. MR imaging data acquired from several phantoms containing interventional devices such as biopsy needles, stent, and brachytherapy seeds, used for validating the proposed technique. The results show that it can speed up data acquisition by a factor of about five while preserving the quality of the positive contrast images.
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Affiliation(s)
- Samira Vafay Eslahi
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
| | - Jim Ji
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA.
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McNabb E, Wong R, Noseworthy MD. Differentiating platinum coated brachytherapy seeds and gold fiducial markers with varying off-resonant frequency offsets. Magn Reson Imaging 2019; 60:68-75. [PMID: 30959177 DOI: 10.1016/j.mri.2019.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 03/14/2019] [Accepted: 04/04/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE To develop an off-resonant frequency filtered method to selectively differentiate between implanted gold fiducial markers and platinum coated brachytherapy seeds. MATERIALS AND METHODS The magnetic susceptibilities for gold fiducial markers and brachytherapy seeds differ in magnitude and also in their signs, resulting in B0-field inhomogeneity patterns with opposite main lobes. A pulse sequence used to localize brachytherapy seeds with positive contrast, centre-out radial sampling with off-resonance reception (co-RASOR), was used to reconstruct images with a range of off-resonant frequency offsets. The proposed method utilizes two frequency filters to selectively reconstruct maximum intensity projections through band-pass regions where each seed has its maximal localized hyperintensity. Seeds were simulated and then placed in gel and tissue phantoms to validate the technique using orthogonal 2D slices with seeds both parallel and perpendicular to the B0-field. RESULTS Dual-plane 2D co-RASOR sequences were reconstructed off-resonance with applied frequency filters to create two projections displaying each seed, which were then colour-coded to negative and positive frequencies. Phantom validation showed that each seed contains its maximal CNR in opposing frequency regions as predicted. Local maxima can also appear in both negative and positive frequency regions. The relative difference between the signal of each seed and these local maxima ranged from 1.19 to 3.73, and an image threshold was determined in all cases. Tissue validation showed the technique differentiates seeds correctly and is limited by the hyperintensity patterns observed in the co-RASOR method. CONCLUSIONS Dual-plane co-RASOR offers sub-millimetre positive contrast from implanted seeds that contain unique off-resonant frequency maxima, which frequency filters can selectively differentiate.
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Affiliation(s)
- Evan McNabb
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Raimond Wong
- Juravinski Cancer Centre, Hamilton, Ontario, Canada; Department of Oncology, McMaster University, Hamilton, Ontario, Canada; Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Noseworthy
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Radiology, McMaster University, Hamilton, Ontario, Canada; Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada.
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Naeyaert M, Roose D, Mai Z, Keliris A, Sijbers J, Van der Linden A, Verhoye M. Normalized averaged range (nAR), a robust quantification method for MPIO-content. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 300:18-27. [PMID: 30684825 DOI: 10.1016/j.jmr.2018.12.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 12/06/2018] [Accepted: 12/20/2018] [Indexed: 06/09/2023]
Abstract
Micron-sized paramagnetic iron oxide particles (MPIO) are commonly used as contrast agents in magnetic resonance imaging (MRI) that produce negative contrast enhancement, i.e. darkening, on T2*-weighted images. However, estimation and quantification of MPIO in vivo is still challenging. This limitation mainly arises from smearing and displacement of the negative contrast of the MPIO, so-called blooming, potentially leading to false-positive detection. Further, the bias field induced by the MR coils also hinders visualization and quantification of the MPIO. To mitigate these drawbacks, a positive contrast image can be generated, for example by using a frequency offset technique, which can significantly improve the accuracy of quantification methods. In this research, we introduce the normalized average range (nAR) as a new way to quantify the relative MPIO content within a study. The method compares the average value of test ROIs to that of a control ROI in range filtered images. The nAR can be used on both positive and negative contrast images. The nAR was tested on agar phantoms containing various MPIO concentrations, and on a rostral migration model for MPIO labeled stem cells in mice. The amount of MPIO was quantified for biased and unbiased data, and both for positive and negative contrast images. In addition, the presence of MPIOs in the olfactory bulb was verified by histology. The results show the nAR can indicate the presence and relative content of MPIO for both negative and positive images. However, the nAR showed slightly higher sensitivity in optimized positive contrast images compared to negative contrast images. In all cases, the bias field played a minor role in the quantification, making debiasing less of a concern. The dependency of the nAR values on the MPIO content in the ROI was further validated histologically. Thus, the nAR provides a robust and reliable tool for quantification of MPIO in mice.
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Affiliation(s)
- Maarten Naeyaert
- Bio-Imaging Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium.
| | - Dimitri Roose
- Bio-Imaging Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
| | - Zhenhua Mai
- Bio-Imaging Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
| | - Aneta Keliris
- Bio-Imaging Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
| | - Jan Sijbers
- imec-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
| | - Annemie Van der Linden
- Bio-Imaging Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
| | - Marleen Verhoye
- Bio-Imaging Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp, Belgium
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McNabb E, Wong R, Noseworthy MD. Resolution and registration in dual-plane co-RASOR MR. Phys Med Biol 2018; 63:215005. [PMID: 30260799 DOI: 10.1088/1361-6560/aae4d5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Magnetic resonance imaging (MRI) has superior soft tissue contrast and lower interobserver variability compared to computed tomography and advances in equipment and pseudo-CT estimation have allowed for MR-only radiation therapy planning. Dedicated MR sequences have been used to localize paramagnetic structures with positive contrast, and most implanted seeds are gold fiducial markers (GFMs). We used a fast, dual-plane co-RASOR sequence to localize implanted GFMs with positive contrast in phantom and tissue to assess their resolution and registration accuracy of registration to CT. Off-resonant reconstructions of co-RASOR images were able to resolve GFMs down to 5 mm apart at 12 cm FOV. No systematic biases were observed by comparing registration of co-RASOR and bSSFP to CT images in an MR-compatible Lego phantom with a set of highly visible known points. The standard deviations of the MR to CT distance errors were <0.5 mm in all directions. We separated the component due to registration by comparing the two MR sequences, which had a maximum standard deviation of 0.36 mm in the SI-direction. Registration using the positive contrast points in a porcine sample phantom showed increased errors, but co-RASOR still performs acceptably with a target registration error of <0.75 mm. The dual-plane co-RASOR sequence could then be used for both registration and image tracking when performing MR-only radiation therapy planning.
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Affiliation(s)
- Evan McNabb
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
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Bouwman JG, Custers BA, Bakker CJG, Viergever MA, Seevinck PR. isoPhasor: a generic and precise marker visualization, localization, and quantification method based on phase saddles in 3D MR imaging. Magn Reson Med 2018; 81:2038-2051. [PMID: 30346055 DOI: 10.1002/mrm.27493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 11/11/2022]
Abstract
PURPOSE To derive a generic approach for accurate localization and characterization of susceptibility markers in MRI, compatible with many common types of pulse sequences, sampling trajectories, and acceleration methods. THEORY AND METHODS A susceptibility marker's dipolar phase evolution creates 3 saddles in the phase gradient of the spatial encoding, for each sampled data point in k-space. The signal originating from these saddles can be focused at the location of the marker to create positive contrast. The required phase shift can be calculated from the scan parameters and the marker properties, providing a marker detection algorithm generic for different scan types. The method was validated numerically and experimentally for a broad range of spherical susceptibility markers (0.3 < radius < 1.6 mm, 10 < |∆χ| < 3300 ppm), under various conditions. RESULTS For all numerical and experimental phantoms, the average localization error was below one third of the voxel size, whereas the average error in magnetic strength quantification was 7%. The experiments included different pulse sequences (gradient echo, spin echo [SE], and free induction decay scans), sampling strategies (Cartesian, radial), and acceleration methods (echo planar imaging EPI, turbo SE). CONCLUSION Spherical markers can be identified from their phase saddles, enabling clear visualization, precise localization, and accurate quantification of their magnetic strength, in a wide range of clinically relevant pulse sequences and sampling strategies.
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Affiliation(s)
- Job G Bouwman
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bram A Custers
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Chris J G Bakker
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Max A Viergever
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter R Seevinck
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
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Beld E, Moerland MA, Zijlstra F, Viergever MA, Lagendijk JJW, Seevinck PR. MR-based source localization for MR-guided HDR brachytherapy. Phys Med Biol 2018. [PMID: 29516866 DOI: 10.1088/1361-6560/aab50b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
For the purpose of MR-guided high-dose-rate (HDR) brachytherapy, a method for real-time localization of an HDR brachytherapy source was developed, which requires high spatial and temporal resolutions. MR-based localization of an HDR source serves two main aims. First, it enables real-time treatment verification by determination of the HDR source positions during treatment. Second, when using a dummy source, MR-based source localization provides an automatic detection of the source dwell positions after catheter insertion, allowing elimination of the catheter reconstruction procedure. Localization of the HDR source was conducted by simulation of the MR artifacts, followed by a phase correlation localization algorithm applied to the MR images and the simulated images, to determine the position of the HDR source in the MR images. To increase the temporal resolution of the MR acquisition, the spatial resolution was decreased, and a subpixel localization operation was introduced. Furthermore, parallel imaging (sensitivity encoding) was applied to further decrease the MR scan time. The localization method was validated by a comparison with CT, and the accuracy and precision were investigated. The results demonstrated that the described method could be used to determine the HDR source position with a high accuracy (0.4-0.6 mm) and a high precision (⩽0.1 mm), at high temporal resolutions (0.15-1.2 s per slice). This would enable real-time treatment verification as well as an automatic detection of the source dwell positions.
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Affiliation(s)
- E Beld
- Department of Radiotherapy, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, Netherlands
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McNabb E, Wong R, Noseworthy MD. Localizing implanted fiducial markers using undersampled co-RASOR MR imaging. Magn Reson Imaging 2017; 48:1-9. [PMID: 29229307 DOI: 10.1016/j.mri.2017.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 12/04/2017] [Indexed: 01/04/2023]
Abstract
The goal of this work was to use an undersampled, dual-plane centre-out radial sampling acquisition pulse sequence, with off-resonance reception, to localize fiducial markers with reduced acquisition time. Two iterative reconstruction techniques, conjugate gradient CG-SENSE and the variational penalty Total Generalized Variation (TGV), were investigated to minimize the undersampling artifacts in off-resonant radial imaging. Simulations of a field perturber were performed at sub-millimeter resolution and reconstructed to display signal pileups that can be radially compressed towards the geometric centre of the perturber for high contrast visualization, but contrast is non-recoverable as the echo time increases. A cylindrical platinum fiducial marker, placed in a phantom parallel and perpendicular to the B0-field was imaged with a short-TE half-echo readout. Contrast-to-Noise (CNR) between the signal of the fiducial its adjacent surrounding shell and half-maximum area were used to compare reconstruction methods and undersampling factors. For single slice acquisitions centred about the fiducial, each slice can be performed in as little as 2.8s. The total acquisition time to localize the fiducial marker in a phantom was reduced to 73s by undersampling (R=8) 37 axial and 15 coronal slices, effectively encoding 1.4s/slice. The noise present in undersampled images, for both scan planes and fiducial orientations, decreased significantly using TGV and CG-SENSE reconstructions, with TGV displaying better spatial resolution from reduced half-maximum area.
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Affiliation(s)
- Evan McNabb
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Canada
| | - Raimond Wong
- Juravinksi Cancer Centre, Hamilton, Ontario, Canada; Department of Oncology, McMaster University, Hamilton, Ontario, Canada; Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Noseworthy
- McMaster School of Biomedical Engineering, McMaster University, Hamilton, Canada; Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada; Department of Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Radiology, McMaster University, Hamilton, Ontario, Canada.
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Maspero M, van den Berg CAT, Zijlstra F, Sikkes GG, de Boer HCJ, Meijer GJ, Kerkmeijer LGW, Viergever MA, Lagendijk JJW, Seevinck PR. Evaluation of an automatic MR-based gold fiducial marker localisation method for MR-only prostate radiotherapy. ACTA ACUST UNITED AC 2017; 62:7981-8002. [DOI: 10.1088/1361-6560/aa875f] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Zijlstra F, Moerland MA, van der Voort van Zyp JRN, Noteboom JL, Viergever MA, Seevinck PR. Challenges in MR-only seed localization for postimplant dosimetry in permanent prostate brachytherapy. Med Phys 2017; 44:5051-5060. [PMID: 28777451 DOI: 10.1002/mp.12505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/17/2017] [Accepted: 07/22/2017] [Indexed: 12/19/2022] Open
Abstract
PURPOSE An MR-only postimplant dosimetry workflow for low dose rate (LDR) brachytherapy could reduce patient burden, improve accuracy, and improve cost efficiency. However, localization of brachytherapy seeds on MRI scans remains a major challenge for this type of workflow. In this study, we propose and validate an MR-only seed localization method and identify remaining challenges. METHODS AND MATERIALS The localization method was based on template matching of simulations of complex-valued imaging artifacts around metal brachytherapy seeds. The method was applied to MRI scans of 25 prostate cancer patients who underwent LDR brachytherapy and for whom postimplant dosimetry was performed after 4 weeks. The seed locations found with the MR-only method were validated against the seed locations found on CT. The circumstances in which detection errors were made were classified to gain an insight in the nature of the errors. RESULTS A total of 1490 of 1557 (96%) seeds were correctly detected, while 67 false-positive errors were made. The correctly detected seed locations had a high spatial accuracy with an average error of 0.8 mm compared with CT. A majority of the false positives occurred near other seeds. Most false negatives were found in either stranded configurations without spacers or near other seeds. CONCLUSIONS The low detection error rate and high localization accuracy obtained by the complex-valued template matching approach are promising for future clinical application of MR-only dosimetry. The most important remaining challenge is robustness with regard to configurations of multiple seeds in close vicinity, such as in strands of seeds without spacers. This issue could potentially be resolved by simulating specific configurations of multiple seeds or by constraining the treatment planning to avoid these configurations, which could make the proposed method competitive with CT-based seed localization.
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Affiliation(s)
- Frank Zijlstra
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marinus A Moerland
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Juus L Noteboom
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Max A Viergever
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Peter R Seevinck
- Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
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Gustafsson C, Korhonen J, Persson E, Gunnlaugsson A, Nyholm T, Olsson LE. Registration free automatic identification of gold fiducial markers in MRI target delineation images for prostate radiotherapy. Med Phys 2017; 44:5563-5574. [DOI: 10.1002/mp.12516] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/14/2017] [Accepted: 08/06/2017] [Indexed: 11/08/2022] Open
Affiliation(s)
- Christian Gustafsson
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund 221 85 Sweden
- Department of Medical Radiation Physics; Lund University; Malmö 205 02 Sweden
| | - Juha Korhonen
- Department of Nuclear Medicine; Helsinki University Central Hospital; Helsinki 00290 Finland
- Department of Radiology; Helsinki University Central Hospital; Helsinki 00290 Finland
- Department of Radiation Therapy; Comprehensive Cancer Center; Helsinki University Central Hospital; Helsinki 00290 Finland
| | - Emilia Persson
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund 221 85 Sweden
- Department of Medical Radiation Physics; Lund University; Malmö 205 02 Sweden
| | - Adalsteinn Gunnlaugsson
- Department of Hematology, Oncology and Radiation Physics; Skåne University Hospital; Lund 221 85 Sweden
| | - Tufve Nyholm
- Department of Radiation Sciences; Umeå University; Umeå 90187 Sweden
- Department of Immunology, Genetics and Pathology; Uppsala University; Uppsala 95105 Sweden
| | - Lars E. Olsson
- Department of Medical Radiation Physics; Lund University; Malmö 205 02 Sweden
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Multispectral 3D phase-encoded turbo spin-echo for imaging near metal: Limitations and possibilities demonstrated by simulations and phantom experiments. Magn Reson Imaging 2017; 39:31-43. [DOI: 10.1016/j.mri.2017.01.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 12/17/2022]
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16
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Lim TY, Kudchadker RJ, Wang J, Stafford RJ, MacLellan C, Rao A, Ibbott GS, Frank SJ. Effect of pulse sequence parameter selection on signal strength in positive-contrast MRI markers for MRI-based prostate postimplant assessment. Med Phys 2017; 43:4312. [PMID: 27370146 DOI: 10.1118/1.4953635] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE For postimplant dosimetric assessment, computed tomography (CT) is commonly used to identify prostate brachytherapy seeds, at the expense of accurate anatomical contouring. Magnetic resonance imaging (MRI) is superior to CT for anatomical delineation, but identification of the negative-contrast seeds is challenging. Positive-contrast MRI markers were proposed to replace spacers to assist seed localization on MRI images. Visualization of these markers under varying scan parameters was investigated. METHODS To simulate a clinical scenario, a prostate phantom was implanted with 66 markers and 86 seeds, and imaged on a 3.0T MRI scanner using a 3D fast radiofrequency-spoiled gradient recalled echo acquisition with various combinations of scan parameters. Scan parameters, including flip angle, number of excitations, bandwidth, field-of-view, slice thickness, and encoding steps were systematically varied to study their effects on signal, noise, scan time, image resolution, and artifacts. RESULTS The effects of pulse sequence parameter selection on the marker signal strength and image noise were characterized. The authors also examined the tradeoff between signal-to-noise ratio, scan time, and image artifacts, such as the wraparound artifact, susceptibility artifact, chemical shift artifact, and partial volume averaging artifact. Given reasonable scan time and managable artifacts, the authors recommended scan parameter combinations that can provide robust visualization of the MRI markers. CONCLUSIONS The recommended MRI pulse sequence protocol allows for consistent visualization of the markers to assist seed localization, potentially enabling MRI-only prostate postimplant dosimetry.
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Affiliation(s)
- Tze Yee Lim
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and The University of Texas at Houston Graduate School of Biomedical Sciences, 6767 Bertner Avenue, Houston, Texas 77030
| | - Rajat J Kudchadker
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Jihong Wang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - R Jason Stafford
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Christopher MacLellan
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and The University of Texas at Houston Graduate School of Biomedical Sciences, 6767 Bertner Avenue, Houston, Texas 77030
| | - Arvind Rao
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Geoffrey S Ibbott
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
| | - Steven J Frank
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030
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17
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Shi C, Xie G, Zhang Y, Zhang X, Chen M, Su S, Dong Y, Liu X, Ji J. Accelerated susceptibility-based positive contrast imaging of MR compatible metallic devices based on modified fast spin echo sequences. Phys Med Biol 2017; 62:2505-2520. [DOI: 10.1088/1361-6560/aa5fa3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Dinis Fernandes C, Dinh CV, Steggerda MJ, ter Beek LC, Smolic M, van Buuren LD, Pos FJ, van der Heide UA. Prostate fiducial marker detection with the use of multi-parametric magnetic resonance imaging. PHYSICS & IMAGING IN RADIATION ONCOLOGY 2017. [DOI: 10.1016/j.phro.2017.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Wang W, Viswanathan AN, Damato AL, Chen Y, Tse Z, Pan L, Tokuda J, Seethamraju RT, Dumoulin CL, Schmidt EJ, Cormack RA. Evaluation of an active magnetic resonance tracking system for interstitial brachytherapy. Med Phys 2016; 42:7114-21. [PMID: 26632065 DOI: 10.1118/1.4935535] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE In gynecologic cancers, magnetic resonance (MR) imaging is the modality of choice for visualizing tumors and their surroundings because of superior soft-tissue contrast. Real-time MR guidance of catheter placement in interstitial brachytherapy facilitates target coverage, and would be further improved by providing intraprocedural estimates of dosimetric coverage. A major obstacle to intraprocedural dosimetry is the time needed for catheter trajectory reconstruction. Herein the authors evaluate an active MR tracking (MRTR) system which provides rapid catheter tip localization and trajectory reconstruction. The authors assess the reliability and spatial accuracy of the MRTR system in comparison to standard catheter digitization using magnetic resonance imaging (MRI) and CT. METHODS The MRTR system includes a stylet with microcoils mounted on its shaft, which can be inserted into brachytherapy catheters and tracked by a dedicated MRTR sequence. Catheter tip localization errors of the MRTR system and their dependence on catheter locations and orientation inside the MR scanner were quantified with a water phantom. The distances between the tracked tip positions of the MRTR stylet and the predefined ground-truth tip positions were calculated for measurements performed at seven locations and with nine orientations. To evaluate catheter trajectory reconstruction, fifteen brachytherapy catheters were placed into a gel phantom with an embedded catheter fixation framework, with parallel or crossed paths. The MRTR stylet was then inserted sequentially into each catheter. During the removal of the MRTR stylet from within each catheter, a MRTR measurement was performed at 40 Hz to acquire the instantaneous stylet tip position, resulting in a series of three-dimensional (3D) positions along the catheter's trajectory. A 3D polynomial curve was fit to the tracked positions for each catheter, and equally spaced dwell points were then generated along the curve. High-resolution 3D MRI of the phantom was performed followed by catheter digitization based on the catheter's imaging artifacts. The catheter trajectory error was characterized in terms of the mean distance between corresponding dwell points in MRTR-generated catheter trajectory and MRI-based catheter digitization. The MRTR-based catheter trajectory reconstruction process was also performed on three gynecologic cancer patients, and then compared with catheter digitization based on MRI and CT. RESULTS The catheter tip localization error increased as the MRTR stylet moved further off-center and as the stylet's orientation deviated from the main magnetic field direction. Fifteen catheters' trajectories were reconstructed by MRTR. Compared with MRI-based digitization, the mean 3D error of MRTR-generated trajectories was 1.5 ± 0.5 mm with an in-plane error of 0.7 ± 0.2 mm and a tip error of 1.7 ± 0.5 mm. MRTR resolved ambiguity in catheter assignment due to crossed catheter paths, which is a common problem in image-based catheter digitization. In the patient studies, the MRTR-generated catheter trajectory was consistent with digitization based on both MRI and CT. CONCLUSIONS The MRTR system provides accurate catheter tip localization and trajectory reconstruction in the MR environment. Relative to the image-based methods, it improves the speed, safety, and reliability of the catheter trajectory reconstruction in interstitial brachytherapy. MRTR may enable in-procedural dosimetric evaluation of implant target coverage.
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Affiliation(s)
- Wei Wang
- Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115 and Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Akila N Viswanathan
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Antonio L Damato
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Yue Chen
- Department of Engineering, The University of Georgia, Athens, Georgia 30602
| | - Zion Tse
- Department of Engineering, The University of Georgia, Athens, Georgia 30602
| | - Li Pan
- Siemens Healthcare USA, Baltimore, Maryland 21287
| | - Junichi Tokuda
- Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | | | - Charles L Dumoulin
- Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
| | - Ehud J Schmidt
- Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | - Robert A Cormack
- Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Boston, Massachusetts 02115
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20
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Soliman AS, Owrangi A, Ravi A, Song WY. Metal artefacts in MRI-guided brachytherapy of cervical cancer. J Contemp Brachytherapy 2016; 8:363-9. [PMID: 27648092 PMCID: PMC5018526 DOI: 10.5114/jcb.2016.61817] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/28/2016] [Indexed: 11/29/2022] Open
Abstract
The importance of assessing the metal-induced artefacts in magnetic resonance imaging (MRI)-guided brachytherapy is growing along with the increasing interest of integrating MRI into the treatment procedure of cervical cancer. Examples of metal objects in use include intracavitary cervical applicators and interstitial needles. The induced artefacts increase the uncertainties in the clinical workflow and can be a potential obstacle for the accurate delivery of the treatment. Overcoming this problem necessitates a good understanding of its originating sources. Several efforts are recorded in the literature to quantify the extent of such artefacts, in phantoms and in clinical practice. Here, we elaborate on the origin of metal-induced artefacts in the light of brachytherapy applications, while summarizing recent efforts that have been made to assess and overcome the induced distortions.
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Affiliation(s)
- Abraam S Soliman
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Physical Sciences Platform, Sunnybrook Research Institute, Toronto
| | - Amir Owrangi
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Ananth Ravi
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Physical Sciences Platform, Sunnybrook Research Institute, Toronto; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - William Y Song
- Department of Medical Physics, Sunnybrook Health Sciences Centre, Toronto; Physical Sciences Platform, Sunnybrook Research Institute, Toronto; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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21
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Henken KR, Seevinck PR, Dankelman J, van den Dobbelsteen JJ. Manually controlled steerable needle for MRI-guided percutaneous interventions. Med Biol Eng Comput 2016; 55:235-244. [PMID: 27108292 PMCID: PMC5272900 DOI: 10.1007/s11517-016-1490-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 03/18/2016] [Indexed: 12/03/2022]
Abstract
This study aims to develop and evaluate a manually controlled steerable needle that is compatible with and visible on MRI to facilitate full intra-procedural control and accurate navigation in percutaneous interventions. The steerable needle has a working channel that provides a lumen to a cutting stylet or a therapeutic instrument. A steering mechanism based on cable-operated compliant elements is integrated in the working channel. The needle can be steered by adjusting the orientation of the needle tip through manipulation of the handle. The steering mechanism is evaluated by recording needle deflection at constant steering angles. A steering angle of 20.3° results in a deflection of 9.1–13.3 mm in gelatin and 4.6–18.9 mm in porcine liver tissue at an insertion depth of 60 mm. Additionally, the possibility to control the needle path under MRI guidance is evaluated in a gelatin phantom. The needle can be steered to targets at different locations while starting from the same initial position and orientation under MRI guidance with generally available sequences. The steerable needle offers flexibility to the physician in control and choice of the needle path when navigating the needle toward the target position, which allows for optimization of individual treatment and may increase target accuracy.
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Affiliation(s)
- Kirsten R Henken
- TUDelft, Biomechanical Engineering, Mekelweg 2, 2628 CD, Delft, The Netherlands.
| | - Peter R Seevinck
- Imaging Division, Image Sciences Institute, University Medical Center, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Jenny Dankelman
- TUDelft, Biomechanical Engineering, Mekelweg 2, 2628 CD, Delft, The Netherlands
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22
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Delangre S, Vuong QL, Po C, Gallez B, Gossuin Y. Improvement of the Off-Resonance Saturation, an MRI sequence for positive contrast with SPM particles: Theoretical and experimental study. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 265:99-107. [PMID: 26894477 DOI: 10.1016/j.jmr.2016.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 02/02/2016] [Accepted: 02/04/2016] [Indexed: 06/05/2023]
Abstract
The SuperParaMagnetic particles (SPM particles) are used as contrast agents in MRI and produce negative contrast with conventional T2 or T2(∗)-weighted sequences. Unfortunately, the SPM particle detection on images acquired with such sequences is sometimes difficult because negative contrast can be created by artifacts such as air bubbles or calcification. To overcome this problem, new sequences as Off-Resonance Saturation (ORS) were developed to produce positive contrast with SPM particles. This work explores a new way to optimize the contrast generated by the ORS sequence by increasing the number of saturation pulses applied before the imaging sequence. This modified sequence is studied with numerical simulations and experiments on agarose gel phantoms. A theoretical model able to predict the contrast for different values of the sequence parameters is also developed. The results show that the contrast increases with the saturation pulses number with an optimal value of three saturation pulses in order to avoid artifacts and limit the Specific Absorption Rate (SAR) effect. The dependence of the contrast on the SPM particle concentration and sequence parameters is comparable to what was observed for the ORS sequence.
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Affiliation(s)
- S Delangre
- Biomedical Physics Unit, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Q L Vuong
- Biomedical Physics Unit, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - C Po
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - B Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Y Gossuin
- Biomedical Physics Unit, Université de Mons, Place du Parc 20, 7000 Mons, Belgium.
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23
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Quantification of susceptibility change at high-concentrated SPIO-labeled target by characteristic phase gradient recognition. Magn Reson Imaging 2015; 34:552-61. [PMID: 26592796 DOI: 10.1016/j.mri.2015.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 11/04/2015] [Accepted: 11/17/2015] [Indexed: 11/21/2022]
Abstract
Phase map cross-correlation detection and quantification may produce highlighted signal at superparamagnetic iron oxide nanoparticles, and distinguish them from other hypointensities. The method may quantify susceptibility change by performing least squares analysis between a theoretically generated magnetic field template and an experimentally scanned phase image. Because characteristic phase recognition requires the removal of phase wrap and phase background, additional steps of phase unwrapping and filtering may increase the chance of computing error and enlarge the inconsistence among algorithms. To solve problem, phase gradient cross-correlation and quantification method is developed by recognizing characteristic phase gradient pattern instead of phase image because phase gradient operation inherently includes unwrapping and filtering functions. However, few studies have mentioned the detectable limit of currently used phase gradient calculation algorithms. The limit may lead to an underestimation of large magnetic susceptibility change caused by high-concentrated iron accumulation. In this study, mathematical derivation points out the value of maximum detectable phase gradient calculated by differential chain algorithm in both spatial and Fourier domain. To break through the limit, a modified quantification method is proposed by using unwrapped forward differentiation for phase gradient generation. The method enlarges the detectable range of phase gradient measurement and avoids the underestimation of magnetic susceptibility. Simulation and phantom experiments were used to quantitatively compare different methods. In vivo application performs MRI scanning on nude mice implanted by iron-labeled human cancer cells. Results validate the limit of detectable phase gradient and the consequent susceptibility underestimation. Results also demonstrate the advantage of unwrapped forward differentiation compared with differential chain algorithms for susceptibility quantification at high-concentrated iron accumulation.
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24
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Abstract
The use of magnetic resonance imaging (MRI) in radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimized, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT.
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Affiliation(s)
- Maria A Schmidt
- Cancer Research UK Cancer Imaging Centre, Royal Marsden Hospital and the Institute of Cancer Research, Downs Road, Sutton, Surrey, SM2 5PT, UK
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25
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Abstract
Several advantages of MR imaging compared with other imaging modalities have provided the rationale for increased attention to MR-guided interventions, including its excellent soft tissue contrast, its capability to show both anatomic and functional information, and no use of ionizing radiation. An important aspect of MR-guided intervention is to provide visualization and navigation of interventional devices relative to the surrounding tissues. This article focuses on the methods for MR-guided active tracking in catheter-based interventions. Practical issues about implementation of active catheter tracking in a clinical setting are discussed and several current application examples are highlighted.
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Affiliation(s)
- Wei Wang
- Radiology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA 02115, USA.
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26
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Gurney-Champion OJ, Lens E, van der Horst A, Houweling AC, Klaassen R, van Hooft JE, Stoker J, van Tienhoven G, Nederveen AJ, Bel A. Visibility and artifacts of gold fiducial markers used for image guided radiation therapy of pancreatic cancer on MRI. Med Phys 2015; 42:2638-47. [DOI: 10.1118/1.4918753] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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27
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Delangre S, Vuong QL, Henrard D, Po C, Gallez B, Gossuin Y. Bottom-up study of the MRI positive contrast created by the Off-Resonance Saturation sequence. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 254:98-109. [PMID: 25863894 DOI: 10.1016/j.jmr.2015.02.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 02/12/2015] [Accepted: 02/24/2015] [Indexed: 06/04/2023]
Abstract
Superparamagnetic iron oxide nanoparticles (SPM particles) are used in MRI to highlight regions such as tumors through negative contrast. Unfortunately, sources as air bubbles or tissues interfaces also lead to negative contrast, which complicates the image interpretation. New MRI sequences creating positive contrast in the particle surrounding, such as the Off-Resonance Saturation sequence (ORS), have thus been developed. However, a theoretical study of the ORS sequence is still lacking, which hampers the optimization of this sequence. For this reason, this work provides a self-consistent analytical expression able to predict the dependence of the contrast on the sequence parameters and the SPM particles properties. This expression was validated by numerical simulations and experiments on agarose gel phantoms on a 11.7 T scanner system. It provides a fundamental understanding of the mechanisms leading to positive contrast, which could allow the improvement of the sequence for future in vivo applications. The influence of the SPM particle relaxivities, the SPM particle concentration, the echo time and the saturation pulse parameters on the contrast were investigated. The best contrast was achieved with SPM particles possessing the smallest transverse relaxivity, an optimal particle concentration and for low echo times.
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Affiliation(s)
- S Delangre
- Biomedical Physics Department, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Q L Vuong
- Biomedical Physics Department, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - D Henrard
- Biomedical Physics Department, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - C Po
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - B Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Y Gossuin
- Biomedical Physics Department, Université de Mons, Place du Parc 20, 7000 Mons, Belgium.
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28
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Diwoky C, Liebmann D, Neumayer B, Reinisch A, Knoll F, Strunk D, Stollberger R. Positive contrast of SPIO-labeled cells by off-resonant reconstruction of 3D radial half-echo bSSFP. NMR IN BIOMEDICINE 2015; 28:79-88. [PMID: 25379657 DOI: 10.1002/nbm.3229] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 06/04/2023]
Abstract
This article describes a new acquisition and reconstruction concept for positive contrast imaging of cells labeled with superparamagnetic iron oxides (SPIOs). Overcoming the limitations of a negative contrast representation as gained with gradient echo and fully balanced steady state (bSSFP), the proposed method delivers a spatially localized contrast with high cellular sensitivity not accomplished by other positive contrast methods. Employing a 3D radial bSSFP pulse sequence with half-echo sampling, positive cellular contrast is gained by adding artificial global frequency offsets to each half-echo before image reconstruction. The new contrast regime is highlighted with numerical intravoxel simulations including the point-spread function for 3D half-echo acquisitions. Furthermore, the new method is validated on the basis of in vitro cell phantom measurements on a clinical MRI platform, where the measured contrast-to-noise ratio (CNR) of the new approach exceeds even the negative contrast of bSSFP. Finally, an in vivo proof of principle study based on a mouse model with a clear depiction of labeled cells within a subcutaneous cell islet containing a cell density as low as 7 cells/mm(3) is presented. The resultant isotropic images show robustness to motion and a high CNR, in addition to an enhanced specificity due to the positive contrast of SPIO-labeled cells.
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Affiliation(s)
- Clemens Diwoky
- Institute of Medical Engineering, Graz University of Technology, Graz, Austria; BioTechMed-Graz, Graz, Austria
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29
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van Gorp JS, Bakker CJG, Bouwman JG, Smink J, Zijlstra F, Seevinck PR. Geometrically undistorted MRI in the presence of field inhomogeneities using compressed sensing accelerated broadband 3D phase encoded turbo spin-echo imaging. Phys Med Biol 2014; 60:615-31. [DOI: 10.1088/0031-9155/60/2/615] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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30
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Dong Y, Chang Z, Xie G, Whitehead G, Ji JX. Susceptibility-based positive contrast MRI of brachytherapy seeds. Magn Reson Med 2014; 74:716-26. [DOI: 10.1002/mrm.25453] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 07/29/2014] [Accepted: 08/23/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Ying Dong
- Department of Electrical and Computer Engineering; Texas A&M University; College Station Texas USA
| | - Zheng Chang
- Department of Radiation Oncology; Duke University; Durham North Carolina USA
| | - Guoxi Xie
- Paul C. Lauterbur Research Center for Biomedical Imaging; Chinese Academy of Sciences; Shenzhen China
- Beijing Center for Mathematics and Information Interdisciplinary Sciences; Beijing China
| | - Gregory Whitehead
- Department of Electrical and Computer Engineering; Texas A&M University; College Station Texas USA
| | - Jim X. Ji
- Department of Electrical and Computer Engineering; Texas A&M University; College Station Texas USA
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31
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Wang W, Dumoulin CL, Viswanathan AN, Tse ZTH, Mehrtash A, Loew W, Norton I, Tokuda J, Seethamraju RT, Kapur T, Damato AL, Cormack RA, Schmidt EJ. Real-time active MR-tracking of metallic stylets in MR-guided radiation therapy. Magn Reson Med 2014; 73:1803-11. [PMID: 24903165 DOI: 10.1002/mrm.25300] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/01/2014] [Accepted: 05/02/2014] [Indexed: 11/10/2022]
Abstract
PURPOSE To develop an active MR-tracking system to guide placement of metallic devices for radiation therapy. METHODS An actively tracked metallic stylet for brachytherapy was constructed by adding printed-circuit micro-coils to a commercial stylet. The coil design was optimized by electromagnetic simulation, and has a radio-frequency lobe pattern extending ∼5 mm beyond the strong B0 inhomogeneity region near the metal surface. An MR-tracking sequence with phase-field dithering was used to overcome residual effects of B0 and B1 inhomogeneities caused by the metal, as well as from inductive coupling to surrounding metallic stylets. The tracking system was integrated with a graphical workstation for real-time visualization. The 3 Tesla MRI catheter-insertion procedures were tested in phantoms and ex vivo animal tissue, and then performed in three patients during interstitial brachytherapy. RESULTS The tracking system provided high-resolution (0.6 × 0.6 × 0.6 mm(3) ) and rapid (16 to 40 frames per second, with three to one phase-field dithering directions) catheter localization in phantoms, animals, and three gynecologic cancer patients. CONCLUSION This is the first demonstration of active tracking of the shaft of metallic stylet in MR-guided brachytherapy. It holds the promise of assisting physicians to achieve better targeting and improving outcomes in interstitial brachytherapy.
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Affiliation(s)
- Wei Wang
- Radiology, Brigham and Women's Hospital, Boston, Massachusetts, USA; Radiation Oncology, Brigham and Women's Hospital, Boston, Massachusetts, USA
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32
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Krafft AJ, Zamecnik P, Maier F, de Oliveira A, Hallscheidt P, Schlemmer HP, Bock M. Passive marker tracking via phase-only cross correlation (POCC) for MR-guided needle interventions: Initial in vivo experience. Phys Med 2013; 29:607-14. [DOI: 10.1016/j.ejmp.2012.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 09/07/2012] [Accepted: 09/20/2012] [Indexed: 10/27/2022] Open
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de Leeuw H, Moerland MA, van Vulpen M, Seevinck PR, Bakker CJG. A dual-plane co-RASOR technique for accurate and rapid tracking and position verification of an Ir-192 source for single fraction HDR brachytherapy. Phys Med Biol 2013; 58:7829-39. [DOI: 10.1088/0031-9155/58/21/7829] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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34
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Vonken EJPA, Schär M, Yu J, Bakker CJG, Stuber M. Direct in vitro comparison of six three-dimensional positive contrast methods for susceptibility marker imaging. J Magn Reson Imaging 2012; 38:344-57. [PMID: 23281151 DOI: 10.1002/jmri.23976] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 10/31/2012] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To compare different techniques for positive contrast imaging of susceptibility markers with MRI for three-dimensional visualization. As several different techniques have been reported, the choice of the suitable method depends on its properties with regard to the amount of positive contrast and the desired background suppression, as well as other imaging constraints needed for a specific application. MATERIALS AND METHODS Six different positive contrast techniques are investigated for their ability to image at 3 Tesla a single susceptibility marker in vitro. The white marker method (WM), susceptibility gradient mapping (SGM), inversion recovery with on-resonant water suppression (IRON), frequency selective excitation (FSX), fast low flip-angle positive contrast SSFP (FLAPS), and iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) were implemented and investigated. RESULTS The different methods were compared with respect to the volume of positive contrast, the product of volume and signal intensity, imaging time, and the level of background suppression. Quantitative results are provided, and strengths and weaknesses of the different approaches are discussed. CONCLUSION The appropriate choice of positive contrast imaging technique depends on the desired level of background suppression, acquisition speed, and robustness against artifacts, for which in vitro comparative data are now available.
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Affiliation(s)
- Evert-jan P A Vonken
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. evertjan–isi.uu.nl
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Kapanen M, Collan J, Beule A, Seppälä T, Saarilahti K, Tenhunen M. Commissioning of MRI-only based treatment planning procedure for external beam radiotherapy of prostate. Magn Reson Med 2012; 70:127-35. [DOI: 10.1002/mrm.24459] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 11/08/2022]
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de Leeuw H, Seevinck PR, Bakker CJG. Center-out radial sampling with off-resonant reconstruction for efficient and accurate localization of punctate and elongated paramagnetic structures. Magn Reson Med 2012; 69:1611-22. [DOI: 10.1002/mrm.24416] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 05/17/2012] [Accepted: 06/24/2012] [Indexed: 11/06/2022]
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37
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Lehto LJ, Sierra A, Corum CA, Zhang J, Idiyatullin D, Pitkänen A, Garwood M, Gröhn O. Detection of calcifications in vivo and ex vivo after brain injury in rat using SWIFT. Neuroimage 2012; 61:761-72. [PMID: 22425671 DOI: 10.1016/j.neuroimage.2012.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 01/31/2012] [Accepted: 03/01/2012] [Indexed: 01/14/2023] Open
Abstract
Calcifications represent one component of pathology in many brain diseases. With MRI, they are most often detected by exploiting negative contrast in magnitude images. Calcifications are more diamagnetic than tissue, leading to a magnetic field disturbance that can be seen in phase MR images. Most phase imaging studies use gradient recalled echo based pulse sequences. Here, the phase component of SWIFT, a virtually zero acquisition delay sequence, was used to detect calcifications ex vivo and in vivo in rat models of status epilepticus and traumatic brain injury. Calcifications were detected in phase and imaginary SWIFT images based on their dipole like magnetic field disturbances. In magnitude SWIFT images, calcifications were distinguished as hypointense and hyperintense. Hypointense calcifications showed large crystallized granules with few surrounding inflammatory cells, while hyperintense calcifications contained small granules with the presence of more inflammatory cells. The size of the calcifications in SWIFT magnitude images correlated with that in Alizarin stained histological sections. Our data indicate that SWIFT is likely to better preserve signal in the proximity of a calcification or other field perturber in comparison to gradient echo due to its short acquisition delay and broad excitation bandwidth. Furthermore, a quantitative description for the phase contrast near dipole magnetic field inhomogeneities for the SWIFT pulse sequence is given. In vivo detection of calcifications provides a tool to probe the progression of pathology in neurodegenerative diseases. In particular, it appears to provide a surrogate marker for inflammatory cells around the calcifications after brain injury.
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Affiliation(s)
- Lauri Juhani Lehto
- Department of Neurobiology, Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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de Leeuw H, Bakker C. Correction of gradient echo images for first and second order macroscopic signal dephasing using phase derivative mapping. Neuroimage 2012; 60:818-29. [DOI: 10.1016/j.neuroimage.2011.11.083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/21/2011] [Accepted: 11/25/2011] [Indexed: 12/26/2022] Open
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Carl M, Koch K, Du J. MR imaging near metal with undersampled 3D radial UTE-MAVRIC sequences. Magn Reson Med 2012; 69:27-36. [PMID: 22374824 DOI: 10.1002/mrm.24219] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 01/13/2012] [Accepted: 01/29/2012] [Indexed: 01/02/2023]
Abstract
Recently developed techniques such as the multiple acquisition with variable resonance image combination and slice encoding for metal artifact correction techniques have improved the ability of clinical magnetic resonance scanners to image near metal implants. These sequences are based on fast spin echo sequences which preclude detection of short T(2) tissues such as tendons, ligaments, and cortical bone. Ultrashort echo time sequences have the potential to detect signals from these tissues. In this study, we investigate the potential of combining ultrashort echo time with multiple acquisition with variable resonance image combination to image short T(2) musculoskeletal tissues adjacent to metallic implants. Different radio frequency excitation pulse types and spectral binning strategies were studied. We found that ultrashort echo time-multiple acquisition with variable resonance image combination sequences were able to significantly reduce typical artifacts near metal, as well as detect very short T(2) signals that are usually not visualized using clinical pulse sequences.
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Affiliation(s)
- Michael Carl
- GE Healthcare, University of California, San Diego, California 92103-8226, USA.
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Abstract
This article aims to provide an educational document of magnetic resonance imaging principles for applied biomedical users of the technology. Basic principles are illustrated using simple experimental models on a preclinical imaging system.
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Affiliation(s)
- W D Foltz
- STTARR Innovation Centre, Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada.
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Bydder GM. Review. The Agfa Mayneord lecture: MRI of short and ultrashort T₂ and T₂* components of tissues, fluids and materials using clinical systems. Br J Radiol 2011; 84:1067-82. [PMID: 22101579 PMCID: PMC3473831 DOI: 10.1259/bjr/74368403] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 04/29/2011] [Accepted: 06/30/2011] [Indexed: 11/05/2022] Open
Abstract
A variety of techniques are now available to directly or indirectly detect signal from tissues, fluids and materials that have short, ultrashort or supershort T₂ or T₂* components. There are also methods of developing image contrast between tissues and fluids in the short T₂ or T₂* range that can provide visualisation of anatomy, which has not been previously seen with MRI. Magnetisation transfer methods can now be applied to previously invisible tissues, providing indirect access to supershort T₂ components. Particular methods have been developed to target susceptibility effects and quantify them after correcting for anatomical distortion. Specific methods have also been developed to image the effects of magnetic iron oxide particles with positive contrast. Major advances have been made in techniques designed to correct for loss of signal and gross image distortion near metal. These methods are likely to substantially increase the range of application for MRI.
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Affiliation(s)
- G M Bydder
- Department of Radiology, University of California San Diego, San Diego, CA 92103-8226, USA.
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