TY  - JOUR
AU  - Weidner, Artur
AU  - Stengl, Christina
AU  - Dinkel, Fabian
AU  - Dorsch, Stefan
AU  - Murillo, Carlos
AU  - Seeber, Steffen
AU  - Gnirs, Regula
AU  - Runz, Armin
AU  - Echner, Gernot
AU  - Karger, Christian P
AU  - Jaekel, Oliver
TI  - An abdominal phantom with anthropomorphic organ motion and multimodal imaging contrast for MR-guided radiotherapy.
JO  - Physics in medicine and biology
VL  - 67
IS  - 4
SN  - 0031-9155
CY  - Bristol
PB  - IOP Publ.
M1  - DKFZ-2022-00175
SP  - 045009
PY  - 2022
N1  - #EA:E040#LA:E040# / 2022 Feb 11;67(4) 045009
AB  - Improvements in image-guided-radiotherapy (IGRT) enable accurate and precise radiotherapy treatments of moving tumors in the abdomen while simultaneously sparing healthy tissue. However, the lack of validation tools for newly developed IGRT hybrid devices such as MR-Linac is an open issue. This study presents an abdominal phantom with respiratory organ motion and multimodal imaging contrast to perform end-to-end tests in IGRT. The abdominal phantom contains anatomically shaped liver and kidney models made of Ni-DTPA and KCl-doped agarose mixtures that can be reproducibly positioned within the phantom. Organ models are wrapped in foil to avoid ion exchange with the surrounding agarose-based fatty tissue and to allow stable imaging contrast. Breathing motion is realized by a diaphragm connected to an actuator that is hydraulically controlled via a programmable logic controller (PLC). With this system, artificial and patient-specific breathing patterns can be carried out. In 1.5 and 3 T magnetic resonance imaging (MRI) and computed tomography (CT) series, diaphragm, liver and kidney motion was measured and compared to the breathing motion of a healthy male volunteer for different breathing amplitudes including shallow, normal and deep breathing. The constructed abdominal phantom demonstrated tissue-equivalent contrast in CT as well as in MRI. T1-weighted (T1w) and T2-weighted (T2w) relaxation times and CT-numbers were 552.9 ms, 48.2 ms and 48.8 HU (liver) and 950.42 ms, 79 ms and 28.2 HU (kidney), respectively. These values were stable for more than one month. Extracted breathing motion from a healthy volunteer revealed a liver to diaphragm motion ratio (LDMR) of 64.4 
KW  - Abdominal breathing phantom (Other)
KW  - Image-guided radiotherapy (Other)
KW  - anthropomorphic image contrast (Other)
KW  - intrafractional breathing motion (Other)
KW  - magnetic resonance-guided radiotherapy (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:35081516
DO  - DOI:10.1088/1361-6560/ac4ef8
UR  - https://inrepo02.dkfz.de/record/178646
ER  -