TY - GEN
T1 - Evaluation of cross-modality electromagnetic interactions in a shielded PET/MRI system
AU - Maramraju, S. H.
AU - Smith, S. D.
AU - Rescia, S.
AU - Stoll, S.
AU - Budassi, M.
AU - Bhadrecha, P.
AU - Ravindranath, B.
AU - Vaska, P.
AU - Woody, C.
AU - Schlyer, D.
PY - 2011
Y1 - 2011
N2 - A small-animal PET/MRI scanner was developed previously that was integrated in a Bruker 9.4 T microMRI system, with which simultaneous PET/MR images of a rat's brain and of a gated mouse-heart were obtained. To minimize electromagnetic interactions in our PET/MRI system, viz., the effect of radiofrequency (RF) pulses in the PET, our modular front-end PET electronics were surrounded with variously configured shields. These included a solid aluminum shield and thin segmented layers of copper shielding. It was noted that the gradient-echo RF pulses had no impact on PET data when the PET electronics were shielded with either the aluminum or copper shields. However, we observed spurious counts in the PET data resulting from high-intensity fast spin-echo RF pulses; compared to the unshielded condition, they were suppressed effectively by the aluminum shield (∼97%) and the double-layer copper shield (∼90%). Using the solid aluminum shield yielded a poorer signal in the MR images than compared to segmented copper shields. Our initial results on shielding demonstrate that we can obtain interference-free PET data during gradient-echo pulses and obtain good-quality MR images with thin copper layers covering the PET detector housing.
AB - A small-animal PET/MRI scanner was developed previously that was integrated in a Bruker 9.4 T microMRI system, with which simultaneous PET/MR images of a rat's brain and of a gated mouse-heart were obtained. To minimize electromagnetic interactions in our PET/MRI system, viz., the effect of radiofrequency (RF) pulses in the PET, our modular front-end PET electronics were surrounded with variously configured shields. These included a solid aluminum shield and thin segmented layers of copper shielding. It was noted that the gradient-echo RF pulses had no impact on PET data when the PET electronics were shielded with either the aluminum or copper shields. However, we observed spurious counts in the PET data resulting from high-intensity fast spin-echo RF pulses; compared to the unshielded condition, they were suppressed effectively by the aluminum shield (∼97%) and the double-layer copper shield (∼90%). Using the solid aluminum shield yielded a poorer signal in the MR images than compared to segmented copper shields. Our initial results on shielding demonstrate that we can obtain interference-free PET data during gradient-echo pulses and obtain good-quality MR images with thin copper layers covering the PET detector housing.
UR - https://www.scopus.com/pages/publications/84863368899
U2 - 10.1109/NSSMIC.2011.6152677
DO - 10.1109/NSSMIC.2011.6152677
M3 - Conference contribution
AN - SCOPUS:84863368899
SN - 9781467301183
T3 - IEEE Nuclear Science Symposium Conference Record
SP - 2500
EP - 2505
BT - 2011 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2011
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2011 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2011
Y2 - 23 October 2011 through 29 October 2011
ER -