Objective ：To investigate the influences of motion artifacts on three-dimensional （3D） reconstruction volume and conformal radiotherapy planning. Methods： A phantom which can mimic the clip motion of lung tumor al...Objective ：To investigate the influences of motion artifacts on three-dimensional （3D） reconstruction volume and conformal radiotherapy planning. Methods： A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeedl6 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy （3D- CRT） plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system （TPS）. Results：For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from - 18.4% to 20.5% for a larger one. Conclusion ：The motion artifacts have great effects on 3 D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.展开更多
Three-dimensional (3D) printing has recently emerged as a new technique in various liver-related surgical fields. There are currently only a few systematic reviews that summarize the evidence of its impact. In order t...Three-dimensional (3D) printing has recently emerged as a new technique in various liver-related surgical fields. There are currently only a few systematic reviews that summarize the evidence of its impact. In order to construct a systematic literature review of the applications and effects of 3D printing in liver surgery, we searched the PubMed, Embase and ScienceDirect databases for relevant titles, according to the PRISMA statement guidelines. We retrieved 162 titles, of which 32 met the inclusion criteria and are reported. The leading application of 3D printing in liver surgery is for preoperative planning. 3D printing techniques seem to be beneficial for preoperative planning and educational tools, despite their cost and time requirements, but this conclusion must be confirmed by additional randomized controlled trials.展开更多
In capsule endoscopy(CE), there is research to develop hardware that enables ‘‘real'' three-dimensional(3-D) video. However, it should not be forgotten that ‘‘true'' 3-D requires dual video images....In capsule endoscopy(CE), there is research to develop hardware that enables ‘‘real'' three-dimensional(3-D) video. However, it should not be forgotten that ‘‘true'' 3-D requires dual video images. Inclusion of two cameras within the shell of a capsule endoscope though might be unwieldy at present. Therefore, in an attempt to approximate a 3-D reconstruction of the digestive tract surface, a software that recovers information-using gradual variation of shading-from monocular two-dimensional CE images has been proposed. Light reflections on the surface of the digestive tract are still a significant problem. Therefore, a phantom model and simulator has been constructed in an attempt to check the validity of a highlight suppression algorithm. Our results confirm that 3-D representation software performs better with simultaneous application of a highlight reduction algorithm. Furthermore, 3-D representation follows a good approximation of the real distance to the lumen surface.展开更多
基金Grant sponsor:Guangzhou Municipal Medicin &Health ProgramGrant number:2006-YB-177
文摘Objective ：To investigate the influences of motion artifacts on three-dimensional （3D） reconstruction volume and conformal radiotherapy planning. Methods： A phantom which can mimic the clip motion of lung tumor along the cranial-caudal direction is constructed by step motor, small ball of polyethylene and potato. Ten different scan protocols were set and CT data of the phantom were acquired by using a commercial GE LightSpeedl6 CT scanner. The 3D reconstruction of the CT data was implemented by adopting volume-rendering technology of GE AdvantageSim 6.0 system. The reconstructed volumes of each target in different scan protocols were measured through 3D measuring tools. Thus, relative deviations of the reconstruction volumes between moving targets and static ones were determined. The three-dimensional conformal radiation therapy （3D- CRT） plans and conformal fields were created and compared for a static/moving target with the WiMRT treatment planning system （TPS）. Results：For a static target, there was no obvious difference among the 3D reconstruction volumes when the CT data were acquired with different pitches and slices. The appearance of 3D reconstruction volume and 3D conformal field of a moving target was quite different from that of static one. The maximum relative deviation is nearly 90% for a moving target scanned with different scan protocols. The relative deviations are variable among the different targets, about from -39.8% to 89.5% for a smaller target and from - 18.4% to 20.5% for a larger one. Conclusion ：The motion artifacts have great effects on 3 D-CRT planning and reconstruction volume, which will greatly induce distorted conformal radiation fields and false DVHs for a moving target.
文摘Three-dimensional (3D) printing has recently emerged as a new technique in various liver-related surgical fields. There are currently only a few systematic reviews that summarize the evidence of its impact. In order to construct a systematic literature review of the applications and effects of 3D printing in liver surgery, we searched the PubMed, Embase and ScienceDirect databases for relevant titles, according to the PRISMA statement guidelines. We retrieved 162 titles, of which 32 met the inclusion criteria and are reported. The leading application of 3D printing in liver surgery is for preoperative planning. 3D printing techniques seem to be beneficial for preoperative planning and educational tools, despite their cost and time requirements, but this conclusion must be confirmed by additional randomized controlled trials.
文摘In capsule endoscopy(CE), there is research to develop hardware that enables ‘‘real'' three-dimensional(3-D) video. However, it should not be forgotten that ‘‘true'' 3-D requires dual video images. Inclusion of two cameras within the shell of a capsule endoscope though might be unwieldy at present. Therefore, in an attempt to approximate a 3-D reconstruction of the digestive tract surface, a software that recovers information-using gradual variation of shading-from monocular two-dimensional CE images has been proposed. Light reflections on the surface of the digestive tract are still a significant problem. Therefore, a phantom model and simulator has been constructed in an attempt to check the validity of a highlight suppression algorithm. Our results confirm that 3-D representation software performs better with simultaneous application of a highlight reduction algorithm. Furthermore, 3-D representation follows a good approximation of the real distance to the lumen surface.
