Towards MRI temperature mapping in real time—the proton resonance frequency method with undersampled radial MRI and nonlinear inverse reconstruction

Zhang, Zhongshuai; Michaelis, Thomas; Frahm, Jens

doi:10.21037/qims.2017.03.03

Cited by 6 publications

(7 citation statements)

References 29 publications

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“…However, the system has a limitation of invasive single-point measurement of temperature. Previous studies have shown that temperature monitoring during HIFU treatment is possible with non-invasive spatial temperature monitoring tools, such as ultrasound and magnetic resonance imaging (MRI) [6, 39, 40]. Ultrasound imaging can track temperature changes by analyzing various temperature-dependent properties such as speed of sound, attenuation, and echo strain of tissue [19, 41].…”

Section: Discussionmentioning

confidence: 99%

“…Ultrasound imaging can track temperature changes by analyzing various temperature-dependent properties such as speed of sound, attenuation, and echo strain of tissue [19, 41]. MRI thermometry can measure the interstitial tissue temperature by utilizing temperature-sensitive MR parameters [6, 40]. Recent non-invasive temperature monitoring techniques, including 3D IR thermal imaging and ultrasound thermometries using passive mapping and shear wave elastography [42–46], can also be incorporated with the proposed HIFU system.…”

Section: Discussionmentioning

confidence: 99%

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Development of temperature controller-integrated portable HIFU driver for thermal coagulation

et al. 2019

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Background Temperature monitoring during high-intensity focused ultrasound (HIFU) therapy on tissue is essential to regulate the degree of thermal coagulation and to achieve the desired treatment outcomes eventually. The aim of the current study was to design and investigate the feasibility of a proportional–integral–derivative (PID) temperature controller-integrated portable HIFU driver for thermal coagulation. Methods A portable HIFU driver was designed and operated at a maximum output voltage of 50 V with pulse-width modulation signals at 2 MHz. The temperature of ex vivo bovine liver tissue was monitored using a K-type thermocouple during the 2-MHz HIFU exposure. Results The tissue temperature was maintained at 60 °C using a PID controller-integrated HIFU driver that modulated the output voltage during the 300-s HIFU exposure. The ex vivo testing demonstrated that the tissue temperature at the focal point approached the chosen temperature, i.e., 60 °C, within 70 s. The temperature was maintained with a deviation of less than 4 °C until the HIFU driver voltage was turned off at 300 s. Conclusions The designed PID controller-integrated HIFU driver can be used as a small portable tool to regulate the tissue temperature in real time and achieve thermal coagulation via HIFU sonication.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Development of temperature controller-integrated portable HIFU driver for thermal coagulation

et al. 2019

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“…In addition to temperature imaging, other advantages of MRI relate to the measurement of further heat‐induced changes, including thermal convection, moisture‐loss and moisture‐redistribution, starch gelatinization, protein denaturation, and phase transition either before, during, or after the heating process (Nott & Hall, 2005). Therefore, this method could be a unique tool to obtain three‐dimensional images and to gain insights into local and dynamic process phenomena of food temperature, where the response time is sufficient (Ebrahimnejad et al., 2018; B. P. Hills et al., 1999; Mariette et al., 2012; Z. Zhang et al., 2017). Furthermore, MRI remains limited in its applicability even in research work by its complexity and costs.…”

Section: Methods Using Physical Effects To Determine the Samples’ Tem...mentioning

confidence: 99%

“…Therefore, this method could be a unique tool to obtain three-dimensional images and to gain insights into local and dynamic process phenomena of food temperature, where the response time is sufficient (Ebrahimnejad et al, 2018;B. P. Hills et al, 1999;Mariette et al, 2012;Z. Zhang et al, 2017).…”

Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Critical assessment of methods for measurement of temperature profiles and heat load history in microwave heating processes—A review

Kalinke

Kubbutat

Dinani

et al. 2022

Comp Rev Food Sci Food Safe

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Limitations of microwave processing due to inhomogeneities of power input and energy absorption have been widely described. Over‐ and underheated product areas influence reproducibility, product quality, and possibly safety. Although a broad range of methods is available for temperature measurement and evaluation of time/temperature effects, none of them is sufficiently able to detect temperature differences and thermally induced effects within the product caused by inhomogeneous heating. The purpose of this review is to critically assess different methods of temperature measurement for their suitability for different microwave applications, namely metallic temperature sensors, thermal imaging, pyrometer measurement, fiber optic sensors, microwave radiometry, magnetic resonance imaging, liquid crystal thermography, thermal paper, and biological and chemical time‐temperature indicators. These methods are evaluated according to their advantages and limitations, method characteristics, and potential interference with the electric field. Special attention is given to spatial resolution, accuracy, handling, and purpose of measurement, that is, development work or online production control. Differences of methods and examples of practical application and failure in microwave‐assisted food processing are discussed with a special focus on microwave pasteurization and microwave‐assisted drying. Based on this assessment, it is suggested that infrared cameras for measuring temperature distribution at the product surface and partially inside the product in combination with a chemical time/temperature indicator (e.g., Maillard reaction, generating heat‐induced color variations, depending on local energy absorption) appear to be the most appropriate system for future practical application in microwave food process control, microwave system development, and product design. Reliable detection of inhomogeneous heating is a prerequisite to counteracte inhomogeneity by a targeted adjustment of process and product parameters in microwave applications.

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“…A green laser with a wavelength of 520 nm was also combined into the ablation laser beam to offer visual indication of the ablation laser location using an MR-compatible fiberscope. A GRE sequence with parameters repetition time (TR)/echo time (TE) = 45/13.8 ms, flip angle = 12°, slice thickness = 8 mm, number of slices = 1, pixel size = 0.625 mm by 0.625 mm, and field of view = 160 mm by 160 mm was implemented to acquire both a magnitude and phase image at a time resolution of 10 s. This could be further accelerated by introducing advanced pulse sequences ( 51 ). The magnitude image directly gives the update of tissue morphology during the laser ablation.…”

Section: Ex Vivo Trialmentioning

confidence: 99%

Soft robotic manipulator for intraoperative MRI-guided transoral laser microsurgery

Fang

Chow

et al. 2021

Sci. Robot.

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Magnetic resonance (MR) imaging (MRI) provides compelling features for the guidance of interventional procedures, including high-contrast soft tissue imaging, detailed visualization of physiological changes, and thermometry. Laser-based tumor ablation stands to benefit greatly from MRI guidance because 3D resection margins alongside thermal distributions can be evaluated in real time to protect critical structures while ensuring adequate resection margins. However, few studies have investigated the use of projection-based lasers like those for transoral laser microsurgery, potentially because dexterous laser steering is required at the ablation site, raising substantial challenges in the confined MRI bore and its strong magnetic field. Here, we propose an MR-safe soft robotic system for MRI-guided transoral laser microsurgery. Owing to its miniature size (Ø12 × 100 mm), inherent compliance, and five degrees of freedom, the soft robot ensures zero electromagnetic interference with MRI and enables safe and dexterous operation within the confined oral and pharyngeal cavities. The laser manipulator is rapidly fabricated with hybrid soft and hard structures and is powered by microvolume (<0.004 milliter) fluid flow to enable laser steering with enhanced stiffness and lowered hysteresis. A learning-based controller accommodates the inherent nonlinear robot actuation, which was validated with laser path–following tests. Submillimeter laser steering accuracy was demonstrated with a mean error < 0.20 mm. MRI compatibility testing demonstrated zero observable image artifacts during robot operation. Ex vivo tissue ablation and a cadaveric head-and-neck trial were carried out under MRI, where we employed MR thermometry to monitor the tissue ablation margin and thermal diffusion intraoperatively.

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Towards MRI temperature mapping in real time—the proton resonance frequency method with undersampled radial MRI and nonlinear inverse reconstruction

Cited by 6 publications

References 29 publications

Development of temperature controller-integrated portable HIFU driver for thermal coagulation

Development of temperature controller-integrated portable HIFU driver for thermal coagulation

Critical assessment of methods for measurement of temperature profiles and heat load history in microwave heating processes—A review

Soft robotic manipulator for intraoperative MRI-guided transoral laser microsurgery

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