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MatMRI and MatHIFU: software toolboxes for real-time monitoring and control of MR-guided HIFU.

Zaporzan B, Waspe AC, Looi T, Mougenot C, Partanen A, Pichardo S - J Ther Ultrasound (2013)

Bottom Line: MatMRI substantially simplifies the real-time acquisition and processing of MR data.MatHIFU facilitates the testing and characterization of new therapy applications using the Philips Sonalleve clinical MR-HIFU system.Under coordination with Philips Healthcare, both MatMRI and MatHIFU are intended to be freely available as open-source software packages to other research groups.

View Article: PubMed Central - HTML - PubMed

Affiliation: Thunder Bay Regional Research Institute, Thunder Bay, Ontario P7B 6V4, Canada ; Electrical Engineering, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada.

ABSTRACT

Background: The availability of open and versatile software tools is a key feature to facilitate pre-clinical research for magnetic resonance imaging (MRI) and magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) and expedite clinical translation of diagnostic and therapeutic medical applications. In the present study, two customizable software tools that were developed at the Thunder Bay Regional Research Institute are presented for use with both MRI and MR-HIFU. Both tools operate in a MATLAB(®;) environment. The first tool is named MatMRI and enables real-time, dynamic acquisition of MR images with a Philips MRI scanner. The second tool is named MatHIFU and enables the execution and dynamic modification of user-defined treatment protocols with the Philips Sonalleve MR-HIFU therapy system to perform ultrasound exposures in MR-HIFU therapy applications.

Methods: MatMRI requires four basic steps: initiate communication, subscribe to MRI data, query for new images, and unsubscribe. MatMRI can also pause/resume the imaging and perform real-time updates of the location and orientation of images. MatHIFU requires four basic steps: initiate communication, prepare treatment protocol, and execute treatment protocol. MatHIFU can monitor the state of execution and, if required, modify the protocol in real time.

Results: Four applications were developed to showcase the capabilities of MatMRI and MatHIFU to perform pre-clinical research. Firstly, MatMRI was integrated with an existing small animal MR-HIFU system (FUS Instruments, Toronto, Ontario, Canada) to provide real-time temperature measurements. Secondly, MatMRI was used to perform T2-based MR thermometry in the bone marrow. Thirdly, MatHIFU was used to automate acoustic hydrophone measurements on a per-element basis of the 256-element transducer of the Sonalleve system. Finally, MatMRI and MatHIFU were combined to produce and image a heating pattern that recreates the word 'HIFU' in a tissue-mimicking heating phantom.

Conclusions: MatMRI and MatHIFU leverage existing MRI and MR-HIFU clinical platforms to facilitate pre-clinical research. MatMRI substantially simplifies the real-time acquisition and processing of MR data. MatHIFU facilitates the testing and characterization of new therapy applications using the Philips Sonalleve clinical MR-HIFU system. Under coordination with Philips Healthcare, both MatMRI and MatHIFU are intended to be freely available as open-source software packages to other research groups.

No MeSH data available.


Related in: MedlinePlus

Graphical user interface for the treatment of MRSA-related abscesses in a mouse model using MR-HIFU. MatMRI was used to capture multi-slice 2D images intended for planning as well as dynamic T1-based, single-slice images for the thermometry. In this example, a treatment with an acoustic power of 25 W was used to produce an elevation of temperature from 37°C to 55°C at the center of an abscess.
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Figure 2: Graphical user interface for the treatment of MRSA-related abscesses in a mouse model using MR-HIFU. MatMRI was used to capture multi-slice 2D images intended for planning as well as dynamic T1-based, single-slice images for the thermometry. In this example, a treatment with an acoustic power of 25 W was used to produce an elevation of temperature from 37°C to 55°C at the center of an abscess.

Mentions: MatMRI was integrated with existing software used to control a table designed for small animal MR-HIFU studies (FUS Instruments, Toronto, Ontario, Canada). Experiments were conducted to test the hypothesis that MR-HIFU can be used as a therapeutic option for the treatment of abscesses related to methicillin-resistant Staphylococcus aureus (MRSA) [8]. The animal protocol was approved by the Animal Care Committee of Lakehead University (AUP 08 2012). A 50- μL subcutaneous injection of an MRSA strain, USA-400 bacteria, at a concentration of 7 × 103/μL was performed on the left flank of BALB/c mice, and an abscess of 6 ±2 mm in length formed after 48 h. The abscess was targeted using a transducer operating at 3 MHz with a focal length of 50 mm and diameter of 32 mm. The focal point was positioned 2 mm underneath the abscess, and an ultrasound exposure was applied over 9 s with an acoustic power of 25 or 35 W. Temperature maps were calculated from the coronal MR images of the subcutaneous region of the left flank using the PRFS technique. Magnetic drift was monitored in the non-heated muscle region, and a correction was applied. MR imaging parameters for thermometry were as follows: field of view (FOV) = 80 mm, pixel size = 1 mm, slice thickness = 3 mm, echo time/repetition time (TE/TR) = 16/23 ms, flip angle = 19°, acquisition matrix = 68×63, reconstruction matrix = 80, echo train length (ETL) = 9, number of excitations (NEX) = 1, and dynamic time = 0.35 s. Figure 2 shows a screenshot of the graphical user interface used to monitor and control the experiments.


MatMRI and MatHIFU: software toolboxes for real-time monitoring and control of MR-guided HIFU.

Zaporzan B, Waspe AC, Looi T, Mougenot C, Partanen A, Pichardo S - J Ther Ultrasound (2013)

Graphical user interface for the treatment of MRSA-related abscesses in a mouse model using MR-HIFU. MatMRI was used to capture multi-slice 2D images intended for planning as well as dynamic T1-based, single-slice images for the thermometry. In this example, a treatment with an acoustic power of 25 W was used to produce an elevation of temperature from 37°C to 55°C at the center of an abscess.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265975&req=5

Figure 2: Graphical user interface for the treatment of MRSA-related abscesses in a mouse model using MR-HIFU. MatMRI was used to capture multi-slice 2D images intended for planning as well as dynamic T1-based, single-slice images for the thermometry. In this example, a treatment with an acoustic power of 25 W was used to produce an elevation of temperature from 37°C to 55°C at the center of an abscess.
Mentions: MatMRI was integrated with existing software used to control a table designed for small animal MR-HIFU studies (FUS Instruments, Toronto, Ontario, Canada). Experiments were conducted to test the hypothesis that MR-HIFU can be used as a therapeutic option for the treatment of abscesses related to methicillin-resistant Staphylococcus aureus (MRSA) [8]. The animal protocol was approved by the Animal Care Committee of Lakehead University (AUP 08 2012). A 50- μL subcutaneous injection of an MRSA strain, USA-400 bacteria, at a concentration of 7 × 103/μL was performed on the left flank of BALB/c mice, and an abscess of 6 ±2 mm in length formed after 48 h. The abscess was targeted using a transducer operating at 3 MHz with a focal length of 50 mm and diameter of 32 mm. The focal point was positioned 2 mm underneath the abscess, and an ultrasound exposure was applied over 9 s with an acoustic power of 25 or 35 W. Temperature maps were calculated from the coronal MR images of the subcutaneous region of the left flank using the PRFS technique. Magnetic drift was monitored in the non-heated muscle region, and a correction was applied. MR imaging parameters for thermometry were as follows: field of view (FOV) = 80 mm, pixel size = 1 mm, slice thickness = 3 mm, echo time/repetition time (TE/TR) = 16/23 ms, flip angle = 19°, acquisition matrix = 68×63, reconstruction matrix = 80, echo train length (ETL) = 9, number of excitations (NEX) = 1, and dynamic time = 0.35 s. Figure 2 shows a screenshot of the graphical user interface used to monitor and control the experiments.

Bottom Line: MatMRI substantially simplifies the real-time acquisition and processing of MR data.MatHIFU facilitates the testing and characterization of new therapy applications using the Philips Sonalleve clinical MR-HIFU system.Under coordination with Philips Healthcare, both MatMRI and MatHIFU are intended to be freely available as open-source software packages to other research groups.

View Article: PubMed Central - HTML - PubMed

Affiliation: Thunder Bay Regional Research Institute, Thunder Bay, Ontario P7B 6V4, Canada ; Electrical Engineering, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada.

ABSTRACT

Background: The availability of open and versatile software tools is a key feature to facilitate pre-clinical research for magnetic resonance imaging (MRI) and magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) and expedite clinical translation of diagnostic and therapeutic medical applications. In the present study, two customizable software tools that were developed at the Thunder Bay Regional Research Institute are presented for use with both MRI and MR-HIFU. Both tools operate in a MATLAB(®;) environment. The first tool is named MatMRI and enables real-time, dynamic acquisition of MR images with a Philips MRI scanner. The second tool is named MatHIFU and enables the execution and dynamic modification of user-defined treatment protocols with the Philips Sonalleve MR-HIFU therapy system to perform ultrasound exposures in MR-HIFU therapy applications.

Methods: MatMRI requires four basic steps: initiate communication, subscribe to MRI data, query for new images, and unsubscribe. MatMRI can also pause/resume the imaging and perform real-time updates of the location and orientation of images. MatHIFU requires four basic steps: initiate communication, prepare treatment protocol, and execute treatment protocol. MatHIFU can monitor the state of execution and, if required, modify the protocol in real time.

Results: Four applications were developed to showcase the capabilities of MatMRI and MatHIFU to perform pre-clinical research. Firstly, MatMRI was integrated with an existing small animal MR-HIFU system (FUS Instruments, Toronto, Ontario, Canada) to provide real-time temperature measurements. Secondly, MatMRI was used to perform T2-based MR thermometry in the bone marrow. Thirdly, MatHIFU was used to automate acoustic hydrophone measurements on a per-element basis of the 256-element transducer of the Sonalleve system. Finally, MatMRI and MatHIFU were combined to produce and image a heating pattern that recreates the word 'HIFU' in a tissue-mimicking heating phantom.

Conclusions: MatMRI and MatHIFU leverage existing MRI and MR-HIFU clinical platforms to facilitate pre-clinical research. MatMRI substantially simplifies the real-time acquisition and processing of MR data. MatHIFU facilitates the testing and characterization of new therapy applications using the Philips Sonalleve clinical MR-HIFU system. Under coordination with Philips Healthcare, both MatMRI and MatHIFU are intended to be freely available as open-source software packages to other research groups.

No MeSH data available.


Related in: MedlinePlus