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 mm3) 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. Magn Reson Med 73:1803-1811, 2015.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1803-1811 |
| Number of pages | 9 |
| Journal | Magnetic Resonance in Medicine |
| Volume | 73 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 1 2015 |
| Externally published | Yes |
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Keywords
- active MR-tracking
- metallic device
- phase-field dithering
- radiation therapy
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
Cite this
Real-time active MR-tracking of metallic stylets in MR-guided radiation therapy. / Wang, Wei; Dumoulin, Charles L.; Viswanathan, Akila; Tse, Zion T H; Mehrtash, Alireza; Loew, Wolfgang; Norton, Isaiah; Tokuda, Junichi; Seethamraju, Ravi T.; Kapur, Tina; Damato, Antonio L.; Cormack, Robert A.; Schmidt, Ehud.
In: Magnetic Resonance in Medicine, Vol. 73, No. 5, 01.05.2015, p. 1803-1811.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Real-time active MR-tracking of metallic stylets in MR-guided radiation therapy
AU - Wang, Wei
AU - Dumoulin, Charles L.
AU - Viswanathan, Akila
AU - Tse, Zion T H
AU - Mehrtash, Alireza
AU - Loew, Wolfgang
AU - Norton, Isaiah
AU - Tokuda, Junichi
AU - Seethamraju, Ravi T.
AU - Kapur, Tina
AU - Damato, Antonio L.
AU - Cormack, Robert A.
AU - Schmidt, Ehud
PY - 2015/5/1
Y1 - 2015/5/1
N2 - 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 mm3) 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. Magn Reson Med 73:1803-1811, 2015.
AB - 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 mm3) 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. Magn Reson Med 73:1803-1811, 2015.
KW - active MR-tracking
KW - metallic device
KW - phase-field dithering
KW - radiation therapy
UR - http://www.scopus.com/inward/record.url?scp=84928048043&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84928048043&partnerID=8YFLogxK
U2 - 10.1002/mrm.25300
DO - 10.1002/mrm.25300
M3 - Article
C2 - 24903165
AN - SCOPUS:84928048043
VL - 73
SP - 1803
EP - 1811
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
SN - 0740-3194
IS - 5
ER -