scholarly journals Whole Three-Dimensional Dosimetry of Carbon Ion Beams with an MRI-Based Nanocomposite Fricke Gel Dosimeter Using Rapid T1 Mapping Method

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 233
Author(s):  
Shinya Mizukami ◽  
Yusuke Watanabe ◽  
Takahiro Mizoguchi ◽  
Tsutomu Gomi ◽  
Hidetake Hara ◽  
...  
Keyword(s):  
Dose Distribution ◽  
Three Dimensional ◽  
Heavy Ion ◽  
Mapping Method ◽  
Ion Beams ◽  
Volume Data ◽  
Gel Dosimeter ◽  
Scanning Time ◽  
Contrast Reduction

MRI-based gel dosimeters are attractive systems for the evaluation of complex dose distributions in radiotherapy. In particular, the nanocomposite Fricke gel dosimeter is one among a few dosimeters capable of accurately evaluating the dose distribution of heavy ion beams. In contrast, reduction of the scanning time is a challenging issue for the acquisition of three-dimensional volume data. In this study, we investigated a three-dimensional dose distribution measurement method for heavy ion beams using variable flip angle (VFA), which is expected to significantly reduce the MRI scanning time. Our findings clarified that the whole three-dimensional dose distribution could be evaluated within the conventional imaging time (20 min) and quality of one cross-section.

Calculation of depth-dose distribution of intermediate energy heavy-ion beams

2002 ◽  
Vol 47 (20) ◽  
pp. 1708-1710 ◽  
Author(s):  
Qiang Li ◽  
Zengquan Wei ◽  
Wenjian Li
Keyword(s):  
Dose Distribution ◽  
Heavy Ion ◽  
Intermediate Energy ◽  
Ion Beams ◽  
Depth Dose ◽  
Depth Dose Distribution

scholarly journals A COMPARISON OF LASER AND STRUCTURED LIGHT SCANNING TECHNOLOGIES FOR ARCHAEOLOGICAL APPLICATIONS

2021 ◽  
Vol 13 (3) ◽  
pp. 111-116
Author(s):  
Nikolaos Papas ◽  
◽  
Konstantinos Tsongas ◽  
Dimitrios Karolidis ◽  
Dimitrios Tzetzis ◽  
...  
Keyword(s):  
Structured Light ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Acquisition Time ◽  
Digital Reference ◽  
Scanning Time ◽  
Actual Equipment ◽  
Scan Data

Reverse engineering and in particular three-dimensional digitization have become an essential part of the documentation of archaeological findings. 3D scanning produces a high-precision digital reference document. The factors that influence the quality of the 3D scanned data are the scanned object’s surface colour, its glossiness and geometry, and the ambient light during the scanning process. However, the actual equipment and scanning technologies are of primary importance. The current paper presents a qualitative and quantitative comparison between two 3D scanning devices of different technologies; structured light 3D scanning and laser 3D scanning. The benchmark for this comparison is an ancient Roman vase from the city of Thessaloniki, Greece. The object was scanned with every possible setting on each scanner, but only one configuration of settings on each device was selected for the final comparison. The main criterion for the final selection of the two 3D models acquired with the use of the two technologies was the proximity in the number of points and polygons produced for digitally restoring the ancient vase in the best possible way. The results indicate important differences regarding the accuracy of the final digital model. The laser technology produced better accuracy but with a significant cost in scanning time and model data size. On the other hand, the structured light technology achieved the optimal combination of scanning quality and accuracy, along with reduced acquisition time of scan data.

An Efficient Compressed Volume Rendering Algorithm Based on GPU

2012 ◽  
Vol 433-440 ◽  
pp. 5448-5452 ◽  
Author(s):  
Li Ping Zhao ◽  
Mei Fang ◽  
Yuan Wang Wei
Keyword(s):  
Vector Quantization ◽  
Volume Rendering ◽  
Graphic Processing Unit ◽  
Three Dimensional ◽  
Mapping Method ◽  
Processing Unit ◽  
Volume Data ◽  
Levels Of Detail ◽  
Graphic Hardware ◽  
Multiple Levels

An efficient compressed volume rendering algorithm is presented. Firstly, the original volume data is compressed by a content-based classified hierarchical vector quantization algorithm. Secondly, the compressed volume data is then transferred to Graphic Processing Unit and decompressed in real time, subsequently, the decompressed data is rendered by a three-dimensional textures mapping method to accelerate the speed of rendering. Experimental results show that, in addition to reasonable fidelity and faster rendering speed, the presented algorithm can obtain multiple levels of detail on the off-the-shelf graphic hardware.

Improvement in beam quality of the JAEA AVF cyclotron for focusing heavy-ion beams with energies of hundreds of MeV

2007 ◽  
Vol 260 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Satoshi Kurashima ◽  
Nobumasa Miyawaki ◽  
Susumu Okumura ◽  
Masakazu Oikawa ◽  
Ken-ichi Yoshida ◽  
...  
Keyword(s):  
Beam Quality ◽  
Heavy Ion ◽  
Ion Beams

scholarly journals Equivalency of the quality of sublethal lesions after photons and high-linear energy transfer ion beams

2017 ◽  
Vol 58 (6) ◽  
pp. 803-808 ◽  
Author(s):  
Yoshiya Furusawa ◽  
Mizuho Nakano-Aoki ◽  
Yoshitaka Matsumoto ◽  
Ryoichi Hirayama ◽  
Alisa Kobayashi ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Linear Energy Transfer ◽  
Ion Beam ◽  
Chinese Hamster ◽  
Heavy Ion ◽  
Ion Beams ◽  
X Rays ◽  
High Let ◽  
High Linear Energy Transfer

Abstract The quality of the sublethal damage (SLD) after irradiation with high–linear energy transfer (LET) ion beams was investigated with low-LET photons. Chinese hamster V79 cells and human squamous carcinoma SAS cells were first exposed to a priming dose of different ion beams at different LETs at the Heavy Ion Medical Accelerator in the Chiba facility. The cells were kept at room temperature and then exposed to a secondary test dose of X-rays. Based on the repair kinetics study, the surviving fraction of cells quickly increased with the repair time, and reached a plateau in 2–3 h, even when cells had received priming monoenergetic high-LET beams or spread-out Bragg peak beams as well as X-ray irradiation. The shapes of the cell survival curves from the secondary test X-rays, after repair of the damage caused by the high-LET irradiation, were similar to those obtained from cells exposed to primary X-rays only. Complete SLD repairs were observed, even when the LET of the primary ion beams was very high. These results suggest that the SLD caused by high-LET irradiation was repaired well, and likewise, the damage caused by the X-rays. In cells where the ion beam had made a direct hit in the core region in an ion track, lethal damage to the domain was produced, resulting in cell death. On the other hand, in domains that had received a glancing hit in the low-LET penumbra region, the SLD produced was completely repaired.

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