Measurement of sub‐zero temperatures in MRI using T1 temperature sensitive soft silicone materials: Applications for MRI‐guided cryosurgery.
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| Title: | Measurement of sub‐zero temperatures in MRI using T |
|---|---|
| Authors: | Hankiewicz, Janusz H.1,2 (AUTHOR) jhankiew@uccs.edu, Celinski, Zbigniew1,2 (AUTHOR), Camley, Robert E.1,2 (AUTHOR) |
| Source: | Medical Physics. Nov2021, Vol. 48 Issue 11, p6844-6858. 15p. |
| Subjects: | Magnetic resonance imaging, Nuclear magnetic resonance spectroscopy, Proton magnetic resonance, Cryosurgery, Temperature measurements, Supercooled liquids |
| Abstract: | Purpose: One standard method, proton resonance frequency shift, for measuring temperature using magnetic resonance imaging (MRI), in MRI‐guided surgeries, fails completely below the freezing point of water. Because of this, we have developed a new methodology for monitoring temperature with MRI below freezing. The purpose of this paper is to show that a strong temperature dependence of the nuclear relaxation time T1 in soft silicone polymers can lead to temperature‐dependent changes of MRI intensity acquired with T1 weighting. We propose the use of silicone filaments inserted in tissue for measuring temperature during MRI‐guided cryoablations. Methods: The temperature dependence of T1 in bio‐compatible soft silicone polymers was measured using nuclear magnetic resonance spectroscopy and MRI. Phantoms, made of bulk silicone materials and put in an MRI‐compatible thermal container with dry ice, allowed temperature measurements ranging from –60°C to + 20°C. T1‐weighted gradient echo images of the phantoms were acquired at spatially uniform temperatures and with a gradient in temperature to determine the efficacy of using these materials as temperature indicators in MRI. Ex vivo experiments on silicone rods, 4 mm in diameter, inserted in animal tissue were conducted to assess the practical feasibility of the method. Results: Measurements of nuclear relaxation times of protons in soft silicone polymers show a monotonic, nearly linear, change with temperature (R2 > 0.98) and have a significant correlation with temperature (Pearson's r > 0.99, p < 0.01). Similarly, the intensity of the MR images in these materials, taken with a gradient echo sequence, are also temperature dependent. There is again a monotonic change in MRI intensity that correlates well with the measured temperature (Pearson's r < ‐0.98 and p < 0.01). The MRI experiments show that a temperature change of 3°C can be resolved in a distance of about 2.5 mm. Based on MRI images and external sensor calibrations for a sample with a gradient in temperature, temperature maps with 3°C isotherms are created for a bulk phantom. Experiments demonstrate that these changes in MRI intensity with temperature can also be seen in 4 mm silicone rods embedded in ex vivo animal tissue. Conclusions: We have developed a new method for measuring temperature in MRI that potentially could be used during MRI‐guided cryoablation operations, reducing both procedure time and cost, and making these surgeries safer. [ABSTRACT FROM AUTHOR] |
| Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
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| Header | DbId: egs DbLabel: Engineering Source An: 153579376 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Measurement of sub‐zero temperatures in MRI using T<subscript>1</subscript> temperature sensitive soft silicone materials: Applications for MRI‐guided cryosurgery. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Hankiewicz%2C+Janusz+H%2E%22">Hankiewicz, Janusz H.</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> jhankiew@uccs.edu</i><br /><searchLink fieldCode="AR" term="%22Celinski%2C+Zbigniew%22">Celinski, Zbigniew</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Camley%2C+Robert+E%2E%22">Camley, Robert E.</searchLink><relatesTo>1,2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Medical+Physics%22">Medical Physics</searchLink>. Nov2021, Vol. 48 Issue 11, p6844-6858. 15p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Magnetic+resonance+imaging%22">Magnetic resonance imaging</searchLink><br /><searchLink fieldCode="DE" term="%22Nuclear+magnetic+resonance+spectroscopy%22">Nuclear magnetic resonance spectroscopy</searchLink><br /><searchLink fieldCode="DE" term="%22Proton+magnetic+resonance%22">Proton magnetic resonance</searchLink><br /><searchLink fieldCode="DE" term="%22Cryosurgery%22">Cryosurgery</searchLink><br /><searchLink fieldCode="DE" term="%22Temperature+measurements%22">Temperature measurements</searchLink><br /><searchLink fieldCode="DE" term="%22Supercooled+liquids%22">Supercooled liquids</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Purpose: One standard method, proton resonance frequency shift, for measuring temperature using magnetic resonance imaging (MRI), in MRI‐guided surgeries, fails completely below the freezing point of water. Because of this, we have developed a new methodology for monitoring temperature with MRI below freezing. The purpose of this paper is to show that a strong temperature dependence of the nuclear relaxation time T1 in soft silicone polymers can lead to temperature‐dependent changes of MRI intensity acquired with T1 weighting. We propose the use of silicone filaments inserted in tissue for measuring temperature during MRI‐guided cryoablations. Methods: The temperature dependence of T1 in bio‐compatible soft silicone polymers was measured using nuclear magnetic resonance spectroscopy and MRI. Phantoms, made of bulk silicone materials and put in an MRI‐compatible thermal container with dry ice, allowed temperature measurements ranging from –60°C to + 20°C. T1‐weighted gradient echo images of the phantoms were acquired at spatially uniform temperatures and with a gradient in temperature to determine the efficacy of using these materials as temperature indicators in MRI. Ex vivo experiments on silicone rods, 4 mm in diameter, inserted in animal tissue were conducted to assess the practical feasibility of the method. Results: Measurements of nuclear relaxation times of protons in soft silicone polymers show a monotonic, nearly linear, change with temperature (R2 > 0.98) and have a significant correlation with temperature (Pearson's r > 0.99, p < 0.01). Similarly, the intensity of the MR images in these materials, taken with a gradient echo sequence, are also temperature dependent. There is again a monotonic change in MRI intensity that correlates well with the measured temperature (Pearson's r < ‐0.98 and p < 0.01). The MRI experiments show that a temperature change of 3°C can be resolved in a distance of about 2.5 mm. Based on MRI images and external sensor calibrations for a sample with a gradient in temperature, temperature maps with 3°C isotherms are created for a bulk phantom. Experiments demonstrate that these changes in MRI intensity with temperature can also be seen in 4 mm silicone rods embedded in ex vivo animal tissue. Conclusions: We have developed a new method for measuring temperature in MRI that potentially could be used during MRI‐guided cryoablation operations, reducing both procedure time and cost, and making these surgeries safer. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Medical Physics is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/mp.15252 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 15 StartPage: 6844 Subjects: – SubjectFull: Magnetic resonance imaging Type: general – SubjectFull: Nuclear magnetic resonance spectroscopy Type: general – SubjectFull: Proton magnetic resonance Type: general – SubjectFull: Cryosurgery Type: general – SubjectFull: Temperature measurements Type: general – SubjectFull: Supercooled liquids Type: general Titles: – TitleFull: Measurement of sub‐zero temperatures in MRI using T1 temperature sensitive soft silicone materials: Applications for MRI‐guided cryosurgery. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Hankiewicz, Janusz H. – PersonEntity: Name: NameFull: Celinski, Zbigniew – PersonEntity: Name: NameFull: Camley, Robert E. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 11 Text: Nov2021 Type: published Y: 2021 Identifiers: – Type: issn-print Value: 00942405 Numbering: – Type: volume Value: 48 – Type: issue Value: 11 Titles: – TitleFull: Medical Physics Type: main |
| ResultId | 1 |
