1
|
Jiang M, Cao F, Zhang Q, Qi Z, Gao Y, Zhang Y, Song B, Wu C, Li M, Xu Y, Zhang X, Wang Y, Wei M, Ji X. Model-predicted brain temperature computational imaging by multimodal noninvasive functional neuromonitoring of cerebral oxygen metabolism and hemodynamics: MRI-derived and clinical validation. J Cereb Blood Flow Metab 2024:271678X241270485. [PMID: 39129194 DOI: 10.1177/0271678x241270485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Brain temperature, a crucial yet under-researched neurophysiological parameter, is governed by the equilibrium between cerebral oxygen metabolism and hemodynamics. Therapeutic hypothermia has been demonstrated as an effective intervention for acute brain injuries, enhancing survival rates and prognosis. The success of this treatment hinges on the precise regulation of brain temperature. However, the absence of comprehensive brain temperature monitoring methods during therapy, combined with a limited understanding of human brain heat transmission mechanisms, significantly hampers the advancement of hypothermia-based neuroprotective therapies. Leveraging the principles of bioheat transfer and MRI technology, this study conducted quantitative analyses of brain heat transfer during mild hypothermia therapy. Utilizing MRI, we reconstructed brain structures, estimated cerebral blood flow and oxygen consumption parameters, and developed a brain temperature calculation model founded on bioheat transfer theory. Employing computational cerebral hemodynamic simulation analysis, we established an intracranial arterial fluid dynamics model to predict brain temperature variations across different therapeutic hypothermia modalities. We introduce a noninvasive, spatially resolved, and optimized mathematical bio-heat model that synergizes model-predicted and MRI-derived data for brain temperature prediction and imaging. Our findings reveal that the brain temperature images generated by our model reflect distinct spatial variations across individual participants, aligning with experimentally observed temperatures.
Collapse
Affiliation(s)
- Miaowen Jiang
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Fuzhi Cao
- School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Qihan Zhang
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Zhengfei Qi
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Yuan Gao
- School of Engineering Medicine, Beihang University, Beijing 100083, China
| | - Yang Zhang
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Baoyin Song
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Chuanjie Wu
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Ming Li
- China-America Institute of Neuroscience and Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yongbo Xu
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin 300203, China
| | - Xin Zhang
- Brainnetome Center, Laboratory of Brain Atlas and Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuan Wang
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Ming Wei
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin 300203, China
- Tianjin University, Tianjin Huanhu Hospital, Tianjin 300203, China
| | - Xunming Ji
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, 100069, China
- Department of Neurology and Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
- China-America Institute of Neuroscience and Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| |
Collapse
|
2
|
Filippou A, Evripidou N, Georgiou A, Nikolaou A, Damianou C. Estimation of the Proton Resonance Frequency Coefficient in Agar-based Phantoms. J Med Phys 2024; 49:167-180. [PMID: 39131424 PMCID: PMC11309147 DOI: 10.4103/jmp.jmp_146_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/26/2024] [Accepted: 03/27/2024] [Indexed: 08/13/2024] Open
Abstract
Aim Agar-based phantoms are popular in high intensity focused ultrasound (HIFU) studies, with magnetic resonance imaging (MRI) preferred for guidance since it provides temperature monitoring by proton resonance frequency (PRF) shift magnetic resonance (MR) thermometry. MR thermometry monitoring depends on several factors, thus, herein, the PRF coefficient of agar phantoms was estimated. Materials and Methods Seven phantoms were developed with varied agar (2, 4, or 6% w/v) or constant agar (6% w/v) and varied silica concentrations (2, 4, 6, or 8% w/v) to assess the effect of the concentration on the PRF coefficient. Each phantom was sonicated using varied acoustical power for a 30 s duration in both a laboratory setting and inside a 3T MRI scanner. PRF coefficients were estimated through linear trends between phase shift acquired using gradient sequences and thermocouple-based temperatures changes. Results Linear regression (R 2 = 0.9707-0.9991) demonstrated a proportional dependency of phase shift with temperature change, resulting in PRF coefficients between -0.00336 ± 0.00029 and -0.00934 ± 0.00050 ppm/°C for the various phantom recipes. Weak negative linear correlations of the PRF coefficient were observed with increased agar. With silica concentrations, the negative linear correlation was strong. For all phantoms, calibrated PRF coefficients resulted in 1.01-3.01-fold higher temperature changes compared to the values calculated using a literature PRF coefficient. Conclusions Phantoms developed with a 6% w/v agar concentration and doped with 0%-8% w/v silica best resemble tissue PRF coefficients and should be preferred in HIFU studies. The estimated PRF coefficients can result in enhanced MR thermometry monitoring and evaluation of HIFU protocols.
Collapse
Affiliation(s)
- Antria Filippou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, Limassol, Cyprus
| | - Nikolas Evripidou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, Limassol, Cyprus
| | - Andreas Georgiou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, Limassol, Cyprus
| | - Anastasia Nikolaou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, Limassol, Cyprus
| | - Christakis Damianou
- Department of Electrical Engineering, Computer Engineering and Informatics, Cyprus University of Technology, Limassol, Cyprus
| |
Collapse
|
3
|
Bruns C, Ringleb R, Prediger I, Euchner F, Bernarding J, Plaumann M. Organic Fluorine Compounds and Their Uses as Molecular MR-Based Temperature Sensors. Chemphyschem 2023; 24:e202300512. [PMID: 37632422 DOI: 10.1002/cphc.202300512] [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: 07/21/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 08/28/2023]
Abstract
The interest in fluorinated substances has increased significantly in recent decades due to their diverse properties and possible uses. An important analytical method in this context is NMR spectroscopy, which provides information on the structure as well as on intermolecular interactions or generally on changes in the environment of the nucleus under consideration. A physical quantity that is of great importance in most studies is temperature. However, this is not always easy, e. g. in shielded systems or within an organism. However, the application potential in chemical reactors or in medical diagnosis and therapy is very high and for this reason 13 fluorinated organic compound were chosen for a first 19 F NMR signal temperature sensitivity examination for determination of local temperatures in solution. Polyfluorinated molecules with separate 19 F MR signals are particularly suitable for temperature determination. Those can be serve as internal error-correcting thermometers without the need of a reference substance. Under these conditions, a 19 F MR signal shift of up to 0.03 ppm/K was detectable. Fluorine position and chemical environment were very important for the temperature sensitivity.
Collapse
Affiliation(s)
- Christian Bruns
- Otto-von-Guericke University Magdeburg, Medical Faculty, Institute of Biometry and Medical Informatics, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Rainer Ringleb
- Otto-von-Guericke University Magdeburg, Medical Faculty, Institute of Biometry and Medical Informatics, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Isabell Prediger
- Otto-von-Guericke University Magdeburg, Medical Faculty, Institute of Biometry and Medical Informatics, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Frederike Euchner
- Otto-von-Guericke University Magdeburg, Medical Faculty, Institute of Biometry and Medical Informatics, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Johannes Bernarding
- Otto-von-Guericke University Magdeburg, Medical Faculty, Institute of Biometry and Medical Informatics, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Markus Plaumann
- Otto-von-Guericke University Magdeburg, Medical Faculty, Institute of Biometry and Medical Informatics, Leipziger Str. 44, 39120, Magdeburg, Germany
| |
Collapse
|
4
|
Dong Z, Kantrowitz JT, Mann JJ. Improving the reproducibility of proton magnetic resonance spectroscopy brain thermometry: Theoretical and empirical approaches. NMR IN BIOMEDICINE 2022; 35:e4749. [PMID: 35475306 DOI: 10.1002/nbm.4749] [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: 11/21/2021] [Revised: 02/25/2022] [Accepted: 04/19/2022] [Indexed: 06/14/2023]
Abstract
In proton magnetic resonance spectroscopy (1 H MRS)-based thermometry of brain, averaging temperatures measured from more than one reference peak offers several advantages, including improving the reproducibility (i.e., precision) of the measurement. This paper proposes theoretically and empirically optimal weighting factors to improve the weighted average of temperatures measured from three references. We first proposed concepts of equivalent noise and equivalent signal-to-noise ratio in terms of frequency measurement and a concept of relative frequency that allows the combination of different peaks in a spectrum for improving the precision of frequency measurement. Based on these, we then derived a theoretically optimal weighting factor and proposed an empirical weighting factor, both involving equivalent noise levels, for a weighted average of temperatures measured from three references (i.e., the singlets of NAA, Cr, and Ch in the 1 H MR spectrum). We assessed these two weighting factors by comparing their errors in measurement of temperatures with the errors of temperatures measured from individual references; we also compared these two new weighting factors with two previously proposed weighting factors. These errors were defined as the standard deviations in repeated measurements or in Monte Carlo studies. Both the proposed theoretical and empirical weighting factors outperformed the two previously proposed weighting factors as well as the three individual references in all phantom and in vivo experiments. In phantom experiments with 4- or 10-Hz line broadening, the theoretical weighting factor outperformed the empirical one, but the latter was superior in all other repeated and Monte Carlo tests performed on phantom and in vivo data. The proposed weighting factors are superior to the two previously proposed weighting factors and can improve the reproducibility of temperature measurement using 1 H MRS-based thermometry.
Collapse
Affiliation(s)
- Zhengchao Dong
- Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, New York, USA
- New York State Psychiatric Institute, New York, New York, USA
| | - Joshua T Kantrowitz
- Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, New York, USA
- New York State Psychiatric Institute, New York, New York, USA
- Nathan Kline Institute, Orangeburg, New York, USA
| | - J John Mann
- Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, New York, USA
- New York State Psychiatric Institute, New York, New York, USA
- Department of Radiology, Columbia University, College of Physicians and Surgeons, New York, New York, USA
| |
Collapse
|
5
|
Stereotactic laser interstitial thermal therapy for the treatment of pediatric drug-resistant epilepsy: indications, techniques, and safety. Childs Nerv Syst 2022; 38:961-970. [PMID: 35274185 DOI: 10.1007/s00381-022-05491-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 03/03/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND MRI-guided laser interstitial thermal therapy (MRgLITT) is a promising alternative to open surgery for treatment of drug-resistant epilepsy, offering significant advantages over traditional approaches for candidate patients, including minimally invasive approach, shorter hospitalization, and decreased patient post-operative discomfort. LITT uses a stereotactically placed fiber optic laser probe to ablate tissue under real-time MR thermometry. METHODS Retrospective chart review of intraoperative and perioperative characteristics was performed for 28 cases of MRgLITT in 25 pediatric patients, ages 4-21 years old, at our institution between 2019 and 2021. MRgLITT ablation of the mesial temporal lobe was performed in 8 cases, extratemporal epileptogenic foci in 9 cases, and for corpus callosotomy in 11 cases. RESULTS At 1 year of follow-up, 53% of all patients experienced improvement in seizure frequency (Engel I or II) (class I: 38%, class II: 15%, class III: 17%, class IV: 31%), including 37% of MTL ablations and 80% extratemporal SOZ ablations. After MRgLITT corpus callosotomy, 71% of patients were free from atonic seizures at most recent follow-up. Median length of hospitalization was 2 days (1-3), including a median ICU stay of 1 day (1-2). CONCLUSION This series demonstrates the safety of MRgLITT as an approach for seizure control in drug-resistant epilepsy. We provide additional evidence that MRgLITT is an effective procedure that is well-tolerated by pediatric patients and is accompanied by an acceptable rate of complications and relatively short hospital stay.
Collapse
|
6
|
Xu G, Zhao Z, Xu K, Zhu J, Roe AW, Xu B, Zhang X, Li J, Xu D. Magnetic resonance temperature imaging of laser-induced thermotherapy using proton resonance frequency shift: evaluation of different sequences in phantom and porcine brain at 7 T. Jpn J Radiol 2022; 40:768-780. [DOI: 10.1007/s11604-022-01263-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
|
7
|
Lee AL, Pandey AK, Chiniforoush S, Mandal M, Li J, Cramer CJ, Haynes CL, Pomerantz WCK. Development of a Highly Responsive Organofluorine Temperature Sensor for 19F Magnetic Resonance Applications. Anal Chem 2022; 94:3782-3790. [PMID: 35191677 PMCID: PMC9683353 DOI: 10.1021/acs.analchem.1c04248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Temperature can affect many biological and chemical processes within a body. During in vivo measurements, varied temperature can impact the accurate quantification of additional abiotic factors such as oxygen. During magnetic resonance imaging (MRI) measurements, the temperature of the sample can increase with the absorption of radiofrequency energy, which needs to be well-regulated for thermal therapies and long exposure. To address this potentially confounding effect, temperature can be probed intentionally using reporter molecules to determine the temperature in vivo. This work describes a combined experimental and computational approach for the design of fluorinated molecular temperature sensors with the potential to improve the accuracy and sensitivity of 19F MRI-based temperature monitoring. These fluorinated sensors are being developed to overcome the temperature sensitivity and tissue limitations of the proton resonance frequency (10 × 10-3 ppm °C-1), a standard parameter used for temperature mapping in MRI. Here, we develop (perfluoro-[1,1'-biphenyl]-4,4'-diyl)bis((heptadecafluorodecyl)sulfane), which has a nearly 2-fold increase in temperature responsiveness, compared to the proton resonance frequency and the 19F MRI temperature sensor perfluorotributylamine, when tested under identical NMR conditions. While 19F MRI is in the early stages of translation into clinical practice, development of alternative sensors with improved diagnostic abilities will help advance the development and incorporation of fluorine magnetic resonance techniques for clinical use.
Collapse
Affiliation(s)
- Amani L Lee
- University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Anil K Pandey
- University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Sina Chiniforoush
- University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Mukunda Mandal
- University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jiaqian Li
- University of Minnesota, Minneapolis, Minnesota 55414, United States
| | | | - Christy L Haynes
- University of Minnesota, Minneapolis, Minnesota 55414, United States
| | | |
Collapse
|
8
|
VilasBoas-Ribeiro I, Curto S, van Rhoon GC, Franckena M, Paulides MM. MR Thermometry Accuracy and Prospective Imaging-Based Patient Selection in MR-Guided Hyperthermia Treatment for Locally Advanced Cervical Cancer. Cancers (Basel) 2021; 13:3503. [PMID: 34298716 PMCID: PMC8303939 DOI: 10.3390/cancers13143503] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 11/17/2022] Open
Abstract
The efficacy of a hyperthermia treatment depends on the delivery of well-controlled heating; hence, accurate temperature monitoring is essential for ensuring effective treatment. For deep pelvic hyperthermia, there are no comprehensive and systematic reports on MR thermometry. Moreover, data inclusion generally lacks objective selection criteria leading to a high probability of bias when comparing results. Herein, we studied whether imaging-based data inclusion predicts accuracy and could serve as a tool for prospective patient selection. The accuracy of the MR thermometry in patients with locally advanced cervical cancer was benchmarked against intraluminal temperature. We found that gastrointestinal air motion at the start of the treatment, quantified by the Jaccard similarity coefficient, was a good predictor for MR thermometry accuracy. The results for the group that was selected for low gastrointestinal air motion improved compared to the results for all patients by 50% (accuracy), 26% (precision), and 80% (bias). We found an average MR thermometry accuracy of 2.0 °C when all patients were considered and 1.0 °C for the selected group. These results serve as the basis for comprehensive benchmarking of novel technologies. The Jaccard similarity coefficient also has good potential to prospectively determine in which patients the MR thermometry will be valuable.
Collapse
Affiliation(s)
- Iva VilasBoas-Ribeiro
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (S.C.); (G.C.v.R.); (M.F.); (M.M.P.)
| | - Sergio Curto
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (S.C.); (G.C.v.R.); (M.F.); (M.M.P.)
| | - Gerard C. van Rhoon
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (S.C.); (G.C.v.R.); (M.F.); (M.M.P.)
- Department of Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, 2629 JB Delft, The Netherlands
| | - Martine Franckena
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (S.C.); (G.C.v.R.); (M.F.); (M.M.P.)
| | - Margarethus M. Paulides
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, 3015 GD Rotterdam, The Netherlands; (S.C.); (G.C.v.R.); (M.F.); (M.M.P.)
- Center for Care and Cure Technologies Eindhoven (C3Te), Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| |
Collapse
|
9
|
Jeong H, Restivo MC, Jezzard P, Hess AT. Assessment of radio-frequency heating of a parallel transmit coil in a phantom using multi-echo proton resonance frequency shift thermometry. Magn Reson Imaging 2020; 77:57-68. [PMID: 33359425 PMCID: PMC7889491 DOI: 10.1016/j.mri.2020.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/27/2020] [Accepted: 12/20/2020] [Indexed: 10/25/2022]
Abstract
We propose a workflow for validating parallel transmission (pTx) radio-frequency (RF) magnetic field heating patterns using Proton-Resonance Frequency shift (PRF)-based MR thermometry. Electromagnetic (EM) and thermal simulations of a 7 T 8-channel dipole coil were done using commercially available software (Sim4Life) to assess RF heating. The fabrication method for a phantom with electrical properties matched to human tissue is also described, along with methods for its electrical and thermal characterisation. Energy was deposited to specific transmit channels, whilst acquiring 3D PRF data using a pair of interleaved RF shim transmit modes. A multi-echo readout and pre-scan stabilisation protocol were used for increased sensitivity and to correct for measurement-to-measurement instabilities. The electrical properties of the phantom were found to be within 10% of the intended values. Adoption of a 14-min stabilisation scan gave sufficient suppression of any evolving background spatial variation in the B0 field to achieve <0.001 °C/mm thermometry drift over 10 min of subsequent scanning. Using two RF shim transmit modes enabled full phantom coverage and combining multiple echo times enabled a 13-54% improvement in the RMSE sensitivity to temperature changes. Combining multiple echoes reduced the peak RMSE by 45% and visually reduced measurement-to-measurement instabilities. A reference fibre optic probe showed temperature deviations from the PRF-estimated temperature to be smaller than 0.5 °C. Given the importance of RF safety in pTx applications, this workflow enables accurate validation of RF heating simulations with minimal additional hardware requirements.
Collapse
Affiliation(s)
- Hongbae Jeong
- Wellcome Centre for Integrative Neuroimaging, FMRIB Division, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Matthew C Restivo
- Laboratory of Imaging Technology, Biochemistry and Biophysics Centre, NHLBI, NIH, Bethesda, MD, United States
| | - Peter Jezzard
- Wellcome Centre for Integrative Neuroimaging, FMRIB Division, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Aaron T Hess
- Centre for Clinical Magnetic Resonance Research, Department of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom; British Heart Foundation Centre for Research Excellence, Oxford, United Kingdom.
| |
Collapse
|
10
|
Blackwell J, Kraśny MJ, O'Brien A, Ashkan K, Galligan J, Destrade M, Colgan N. Proton Resonance Frequency Shift Thermometry: A Review of Modern Clinical Practices. J Magn Reson Imaging 2020; 55:389-403. [PMID: 33217099 DOI: 10.1002/jmri.27446] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/02/2020] [Accepted: 11/02/2020] [Indexed: 12/22/2022] Open
Abstract
Magnetic resonance imaging (MRI) has become a popular modality in guiding minimally invasive thermal therapies, due to its advanced, nonionizing, imaging capabilities and its ability to record changes in temperature. A variety of MR thermometry techniques have been developed over the years, and proton resonance frequency (PRF) shift thermometry is the current clinical gold standard to treat a variety of cancers. It is used extensively to guide hyperthermic thermal ablation techniques such as high-intensity focused ultrasound (HIFU) and laser-induced thermal therapy (LITT). Essential attributes of PRF shift thermometry include excellent linearity with temperature, good sensitivity, and independence from tissue type. This noninvasive temperature mapping method gives accurate quantitative measures of the temperature evolution inside biological tissues. In this review, the current status and new developments in the fields of MR-guided HIFU and LITT are presented with an emphasis on breast, prostate, bone, uterine, and brain treatments. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.
Collapse
Affiliation(s)
- James Blackwell
- Advanced Biological Imaging Laboratory, School of Physics, National University of Ireland Galway, Galway, Ireland.,School of Mathematics, Statistics and Applied Mathematics, National University of Ireland Galway, Galway, Ireland
| | - Marcin J Kraśny
- Advanced Biological Imaging Laboratory, School of Physics, National University of Ireland Galway, Galway, Ireland
| | - Aoife O'Brien
- School of Psychology, National University of Ireland Galway, Galway, Ireland
| | - Keyoumars Ashkan
- Neurosurgical Department, King's College Hospital Foundation Trust, London, UK.,Harley Street Clinic, London Neurosurgery Partnership, London, UK
| | - Josette Galligan
- Department of Medical Physics and Bioengineering, St. James' Hospital, Dublin, Ireland
| | - Michel Destrade
- School of Mathematics, Statistics and Applied Mathematics, National University of Ireland Galway, Galway, Ireland
| | - Niall Colgan
- Advanced Biological Imaging Laboratory, School of Physics, National University of Ireland Galway, Galway, Ireland
| |
Collapse
|
11
|
Updating the Risk Stratification for Sudden Cardiac Death in Cardiomyopathies: The Evolving Role of Cardiac Magnetic Resonance Imaging. An Approach for the Electrophysiologist. Diagnostics (Basel) 2020; 10:diagnostics10080541. [PMID: 32751773 PMCID: PMC7460122 DOI: 10.3390/diagnostics10080541] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022] Open
Abstract
The prevention of sudden cardiac death (SCD) in cardiomyopathies (CM) remains a challenge. The current guidelines still favor the implantation of devices for the primary prevention of SCD only in patients with severely reduced left ventricular ejection fraction (LVEF) and heart failure (HF) symptoms. The implantation of an implantable cardioverter-defibrillator (ICD) is a protective barrier against arrhythmic events in CMs, but the benefit does not outweigh the cost in low risk patients. The identification of high risk patients is the key to an individualized prevention strategy. Cardiac magnetic resonance (CMR) provides reliable and reproducible information about biventricular function and tissue characterization. Furthermore, late gadolinium enhancement (LGE) quantification and pattern of distribution, as well as abnormal T1 mapping and extracellular volume (ECV), representing indices of diffuse fibrosis, can enhance our ability to detect high risk patients. CMR can also complement electro-anatomical mapping (EAM), a technique already applied in the risk evaluation and in the ventricular arrhythmias ablation therapy of CM patients, providing a more accurate assessment of fibrosis and arrhythmic corridors. As a result, CMR provides a new insight into the pathological substrate of CM. CMR may help identify high risk CM patients and, combined with EAM, can provide an integrated evaluation of scar and arrhythmic corridors in the ablative therapy of ventricular arrhythmias.
Collapse
|
12
|
Blackwell J, Oluniran G, Tuohy B, Destrade M, Kraśny MJ, Colgan N. Experimental assessment of clinical MRI-induced global SAR distributions in head phantoms. Phys Med 2019; 66:113-118. [PMID: 31593874 DOI: 10.1016/j.ejmp.2019.09.242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/05/2019] [Accepted: 09/28/2019] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVE Accurate estimation of SAR is critical to safeguarding vulnerable patients who require an MRI procedure. The increased static field strength and RF duty cycle capabilities in modern MRI scanners mean that systems can easily exceed safe SAR levels for patients. Advisory protocols routinely used to establish quality assurance protocols are not required to advise on the testing of MRI SAR levels and is not routinely measured in annual medical physics quality assurance checks. This study aims to develop a head phantom and protocol that can independently verify global SAR for MRI clinical scanners. METHODS A four-channel birdcage head coil was used for RF transmission and signal reception. Proton resonance shift thermometry was used to estimate SAR. The SAR estimates were verified by comparing results against two other independent measures, then applied to a further four scanners at field strengths of 1.5 T and 3 T. RESULTS Scanner output SAR values ranged from 0.42 to 1.52 W/kg. Percentage SAR differences between independently estimated values and those calculated by the scanners differed by 0-2.3%. CONCLUSION We have developed a quality assurance protocol to independently verify the SAR output of MRI scanners.
Collapse
Affiliation(s)
- J Blackwell
- School of Physics, National University of Ireland Galway, Galway, Ireland; School of Mathematics, Statistics and Applied Mathematics, National University of Ireland Galway, Galway, Ireland.
| | - G Oluniran
- School of Physics, National University of Ireland Galway, Galway, Ireland
| | - B Tuohy
- Medical Physics and Bioengineering, Galway University Hospital, Galway, Ireland
| | - M Destrade
- School of Mathematics, Statistics and Applied Mathematics, National University of Ireland Galway, Galway, Ireland
| | - M J Kraśny
- School of Physics, National University of Ireland Galway, Galway, Ireland
| | - N Colgan
- School of Physics, National University of Ireland Galway, Galway, Ireland
| |
Collapse
|
13
|
Alattar AA, Bartek J, Chiang VL, Mohammadi AM, Barnett GH, Sloan A, Chen CC. Stereotactic Laser Ablation as Treatment of Brain Metastases Recurring after Stereotactic Radiosurgery: A Systematic Literature Review. World Neurosurg 2019; 128:134-142. [DOI: 10.1016/j.wneu.2019.04.200] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/20/2019] [Accepted: 04/22/2019] [Indexed: 12/21/2022]
|
14
|
Johnson SL, Christensen DA, Dillon CR, Payne A. Validation of hybrid angular spectrum acoustic and thermal modelling in phantoms. Int J Hyperthermia 2018; 35:578-590. [PMID: 30320518 PMCID: PMC6365205 DOI: 10.1080/02656736.2018.1513168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 08/03/2018] [Accepted: 08/13/2018] [Indexed: 12/15/2022] Open
Abstract
In focused ultrasound (FUS) thermal ablation of diseased tissue, acoustic beam and thermal simulations enable treatment planning and optimization. In this study, a treatment-planning methodology that uses the hybrid angular spectrum (HAS) method and the Pennes' bioheat equation (PBHE) is experimentally validated in homogeneous tissue-mimicking phantoms. Simulated three-dimensional temperature profiles are compared to volumetric MR thermometry imaging (MRTI) of FUS sonications in the phantoms, whose acoustic and thermal properties are independently measured. Additionally, Monte Carlo (MC) uncertainty analysis is performed to quantify the effect of tissue property uncertainties on simulation results. The mean error between simulated and experimental spatiotemporal peak temperature rise was +0.33°C (+6.9%). Despite this error, the experimental temperature rise fell within the expected uncertainty of the simulation, as determined by the MC analysis. The average errors of the simulated transverse and longitudinal full width half maximum (FWHM) of the profiles were -1.9% and 7.5%, respectively. A linear regression and local sensitivity analysis revealed that simulated temperature amplitude is more sensitive to uncertainties in simulation inputs than in the profile width and shape. Acoustic power, acoustic attenuation and thermal conductivity had the greatest impact on peak temperature rise uncertainty; thermal conductivity and volumetric heat capacity had the greatest impact on FWHM uncertainty. This study validates that using the HAS and PBHE method can adequately predict temperature profiles from single sonications in homogeneous media. Further, it informs the need to accurately measure or predict patient-specific properties for improved treatment planning of ablative FUS surgeries.
Collapse
Affiliation(s)
- Sara L. Johnson
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
| | - Douglas A. Christensen
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
- Department of Computer and Electrical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Christopher R. Dillon
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| | - Allison Payne
- Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
15
|
Alghamdi NA, Hankiewicz JH, Anderson NR, Stupic KF, Camley RE, Przybylski M, Zukrowski J, Celinski Z. Development of Ferrite-Based Temperature Sensors for Magnetic Resonance Imaging: A Study of Cu 1-xZn xFe 2O 4. PHYSICAL REVIEW APPLIED 2018; 9:10.1103/PhysRevApplied.9.054030. [PMID: 31093520 PMCID: PMC6512831 DOI: 10.1103/physrevapplied.9.054030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We investigate the use of Cu1-x Zn x Fe2O4 ferrites (0.60 < x < 0.76) as potential sensors for magnetic- resonance-imaging thermometry. Samples are prepared by a standard ceramic technique. Their structural and magnetic properties are determined using x-ray diffraction, scanning electron microscopy, super-conducting quantum-interference device magnetometry, and Mossbauer and 3-T nuclear-magnetic-resonance spectroscopies. We use the mass magnetization of powdered ferrites and transverse relaxivity r*2 of water protons in Ringer's-solution-based agar gels with embedded micron-sized particles to determine the best composition for magnetic-resonance-imaging (MRI) temperature sensors in the (280-323)-K range. A preclinical 3-T MRI scanner is employed to acquire T*2 weighted temperature-dependent images. The brightness of the MRI images is cross-correlated with the temperature of the phantoms, which allows for a temperature determination with approximately 1°C accuracy. We determine that the composition of 0.65 < x < 0.70 is the most suitable for MRI thermometry near human body temperature.
Collapse
Affiliation(s)
- N. A. Alghamdi
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs 1420 Austin Bluffs Parkway, Colorado 80918, USA
- Corresponding author.
| | - J. H. Hankiewicz
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs 1420 Austin Bluffs Parkway, Colorado 80918, USA
| | - N. R. Anderson
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs 1420 Austin Bluffs Parkway, Colorado 80918, USA
| | - K. F. Stupic
- National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - R. E. Camley
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs 1420 Austin Bluffs Parkway, Colorado 80918, USA
| | - M. Przybylski
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, 30-059 Krakow, Poland
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland
| | - J. Zukrowski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland
| | - Z. Celinski
- UCCS BioFrontiers Center, University of Colorado, Colorado Springs 1420 Austin Bluffs Parkway, Colorado 80918, USA
| |
Collapse
|