• Radiation Oncology Journal
• /
• v.31 no.4
• /
• pp.247-251
• /
• 2013

Purpose: This study aimed to investigate efficient approaches for determining internal target volume (ITV) from four-dimensional computed tomography (4D CT) images used in stereotactic body radiotherapy (SBRT) for patients with early-stage non-small cell lung cancer (NSCLC). Materials and Methods: 4D CT images were analyzed for 15 patients who received SBRT for stage I NSCLC. Three different ITVs were determined as follows: combining clinical target volume (CTV) from all 10 respiratory phases ($ITV_{10Phases}$); combining CTV from four respiratory phases, including two extreme phases (0% and 50%) plus two intermediate phases (20% and 70%) ($ITV_{4Phases}$); and combining CTV from two extreme phases ($ITV_{2Phases}$). The matching index (MI) of $ITV_{4Phases}$ and $ITV_{2Phases}$ was defined as the ratio of $ITV_{4Phases}$ and $ITV_{2Phases}$, respectively, to the $ITV_{10Phases}$. The tumor motion index (TMI) was defined as the ratio of $ITV_{10Phases}$ to $CTV_{mean}$, which was the mean of 10 CTVs delineated on 10 respiratory phases. Results: The ITVs were significantly different in the order of $ITV_{10Phases}$, $ITV_{4Phases}$, and $ITV_{2Phases}$ (all p < 0.05). The MI of $ITV_{4Phases}$ was significantly higher than that of $ITV_{2Phases}$ (p < 0.001). The MI of $ITV_{4Phases}$ was inversely related to TMI (r = -0.569, p = 0.034). In a subgroup with low TMI (n = 7), $ITV_{4Phases}$ was not statistically different from $ITV_{10Phases}$ (p = 0.192) and its MI was significantly higher than that of $ITV_{2Phases}$ (p = 0.016). Conclusion: The $ITV_{4Phases}$ may be an efficient approach alternative to optimal $ITV_{10Phases}$ in SBRT for early-stage NSCLC with less tumor motion.

• Progress in Medical Physics
• /
• v.25 no.1
• /
• pp.53-63
• /
• 2014

The objective of this study is to investigate the difference of ITV lengths and ITVs between 4DCT and Slow-CT images according to respiratory patterns using a respiratory motion phantom. The respiratory periods 1~4 s and target motion 1~3 cm were applied on each respiratory pattern. 4DCT and Slow-CT images were acquired for 3 times. 4DCT and Slow-CT ITVs were measured with contouring the target in the Eclipse RTP system. The measured ITV lenghts and ITVs in 4DCT and Slow-CT images were compared to the known values. For the ITV lengths and ITVs in the 4DCT, the difference of them were reduced as the respiratory period is longer and target motion is shorter. For the Slow-CT, there was same tendency with change in 4DCT ITV lengths and ITVs about target motion. However, the difference of ITV lengths and ITVs for the respiratory periods were the lowest in respiratory period 1 second and different slightly within respiratory period 2-4 seconds. According to the respiratory patterns, pattern A had the highest reproducibility. Pattern B, C and D were showed the difference similar to each other. However, for pattern E, the reproducibility was the lowest compared with other four patterns. The difference of ITV lengths and ITVs between Slow-CT and 4DCT was increased by increasing the respiratory periods and target motion for all respiratory patterns. When the difference of Slow-CT ITV lengths and ITVs were compared with that of 4DCT ITV lengths and ITVs, Slow-CT ITV lengths and ITVs were approximately 22 % smaller than 4DCT, and the representations of target were different in each pattern. In case of pattern A, B and C, length difference was 3 mm at S (superior) and I (inferior) direction, and the length difference of pattern D was 1.45 cm at only "I" direction whereas the length difference of pattern E was 5 mm longer in "S" direction than "I" direction. Therefore, the margin in SI directions should be determined by considering the respiratory patterns when the margin of Slow-CT is compensated for 4DCT ITV lengths. Afterward, we think that the result of this study will be useful to analyze the ITV lengths and ITVs from the CT images on the basis of the patient respiratory signals.

• Korean journal of communication and information
• /
• v.20
• /
• pp.7-32
• /
• 2003

This essay provides a critical introduction to some of the major issues relating to ITV Digital. The demise of ITV Digital has hit the economics of broadcasting industry in UK. ITV Digital's failure is seen as digital nightmare. This study approaches to three dimensions of the failed ITV Digital. There are the failure of policy, business strategy, technological debacle. As I have discussed, competitive environment of digital broadcasting squeezed ITV Digital into financial trouble. In order to examine current development of digital terrestrial television, three questions have been raised. First, What is the government of digital broadcasting? Second, What is the business strategy of ITV Digital? In particular, the failure of business model deserved careful watching. Third, What is the failure of digital technology?

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.04b
• /
• pp.417-419
• /
• 2000

본 논문은 실시간 운영체제 기반의 ITV 시스템에서 MPEG-4 멀티미디어 장면을 실시간으로 랜더링하는 방법을 제시한다. MPEG-4 멀티미디어 스트림의 랜더링을 위한 장면 구성은 ITV 시스템에서 네트워크를 통해 전송되는 멀티미디어 스트림을 파싱 및 해석하여 장면그래프를 구성하고, 장면 랜더러가 이 장면 그래프를 이용하여 화면에 실시간으로 랜더링한다. MPEG-4 장면 랜더링 화면에서 사용자의 객체 교체나 객체 속성 변환 랜더링 이벤트가 발생하면, MPEG-4 장면 그래프를 실시간으로 갱신시켜 사용자 인터페이스에 랜더링한다.

• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.220-229
• /
• 2013

Respiratory-induced dynamic tumors render free-breathing cone-beam computed tomography (FBCBCT) images with motion artifacts complicating the task of quantifying the internal target volume (ITV). The purpose of this paper is to study the visibility of the revealed ITV when the imaging dose parameters, such as the kVp and mAs, are varied. The $Trilogy^{TM}$ linear accelerator with an On-Board Imaging ($OBI^{TM}$) system was used to acquire low-imaging-dose-mode (LIDM: 110 kVp, 20 mA, 20 ms/frame) and high-imaging-dose-mode (HIDM: 125 kVp, 80 mA, 25 ms/frame) FBCBCT images of a 3-cm diameter sphere (density=0.855 $g/cm^3$) moving in accordance to various sinusoidal breathing patterns, each with an unique inhalation-to-exhalation (I/E) ratio, amplitude, and period. In terms of image ITV contrast, there was a small overall average change of the ITV contrast when going from HIDM to LIDM of $6.5{\pm}5.1%$ for all breathing patterns. As for the ITV visible volume measurements, there was an insignificant difference between the ITV of both the LIDM- and HIDM-FBCBCT images with an average difference of $0.5{\pm}0.5%$, for all cases, despite the large difference in the imaging dose (approximately five-fold difference of ~0.8 and 4 cGy/scan). That indicates that the ITV visibility is not very sensitive to changes in imaging dose. However, both of the FBCBCT consistently underestimated the true ITV dimensions by up to 34.8% irrespective of the imaging dose mode due to significant motion artifacts, and thus, this imaging technique is not adequate to accurately visualize the ITV for image guidance. Due to the insignificant impact of imaging dose on ITV visibility, a plausible, alternative strategy would be to acquire more X-ray projections at the LIDM setting to allow 4DCBCT imaging to better define the ITV, and at the same time, maintain a reasonable imaging dose, i.e., comparable to a single HIDM-FBCBCT scan.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.04a
• /
• pp.159-164
• /
• 2000

이 논문에서는 조립형 실시간 OS에서 운용되는 지능형 텔레비젼(Intelligent Television, ITV)을 개발한다. 인터넷에서의 웹기반 TV에 대하여 여러 연구가 있었지만, 실시간 운영체제가 아니어서 여러 문제를 가지고 있다. 이 논문은 실시간 OS에서의 ITV 개발에서 MPEG-4 프리젠터를 중심으로 설명한다. 즉, 미디어 서버에서 분배 관리기, MPEG-4 압축, 미디어 재생기까지의 일련의 미디어 전송 과정을 거쳐 프리젠테이션 과정을 기술한다. 이 논문의 ITV는 한국전자통신연구원에서 개발 중인 실시간 운영체제에서 운용되며, MPEG-1은 물론 MPEG-4 스트림을 지원함으로써 사용자 상호작용이 효율적이다. 또한, MPEG-7 스트림으로 확장될 수 있다. 이 연구의 결과는 QoS는 물론 전송과 재생 속도의 향상을 가져오므로 디지털 TV(DTV) 등에 활용될 수 있다.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2002.05a
• /
• pp.371.2-371
• /
• 2002

• The Journal of the Korea Contents Association
• /
• v.15 no.8
• /
• pp.416-423
• /
• 2015

The study was conducted targeting 25 patients who underwent the respiratory gated radiation therapy in the abdominal region at Radiation Oncology of a University Hospital from December 2013 to June 2014 and types of cancer included liver(64%), CBD(8%), gastric(8%), GB(8%), pancreas(8%), SMA(4%). The means of ITV and PTV volume are 471.44 cm3 and 425.48 cm3, showing an increase in volume. Normal tissue volume was also found to have increased due to the increase of the section selected from PTV section to ITV section. Right kidney showed a significant increase in differences between increase in normal tissue volume, increase in target volume and increase in therapy irradiation area and difference between the means of dose applied to normal tissue. There was no significant difference in the mean dose applied to normal tissue according to the respiratory average. Both kidneys showed a significant difference in the difference between mean doses of target moving and normal tissue. In this study, both therapy methods through PTV section and ITV section volume setting were appropriate for protection doses of normal tissue and distributed over 95% of the prescribed dose and therefore, it is considered to be okay to be optionally used depending on the patient's therapeutic purpose. But in order to minimize the unexpected side effect, the plan of PTV section and ITV section should be established and used by evaluating normal tissue protection dose.

• The korean journal of orthodontics
• /
• v.41 no.4
• /
• pp.280-287
• /
• 2011

Objective: This study compared the stability of cylindrical miniscrews (Cy, 7 mm in length) with that of tapered miniscrews (Ta, 5 mm in length), using torque values to determine if the healing time before loading affects the stability of the miniscrew and if the insertion torque is associated with the removal torque measured after a few weeks of healing. Methods: Ta and Cy with different thread lengths were placed in the tibias of 12 female New Zealand white rabbits (body weight: 3.0 - 3.5 kg), and the maximum insertion torque values (ITV) were measured. No orthodontic forces were applied so as to allow us to determine the pure effects of the different shapes. After 3 different healing periods (2, 4, and 6 weeks), maximum removal torque values (RTV) were measured immediately before the rabbits were sacrificed. Results: No miniscrews were loosened. There were no significant differences in ITV or RTV between the Ta and Cy nor were there any significant differences in the ITV and RTV between the 3 groups, which had different healing periods. There was a correlation between the ITV and RTV. Conclusions: Shorter Ta showed similar stability as Cy, as determined by torque values. This result strongly suggests that the tapered shape is more advantageous than the cylindrical shape. The RTV did not increase significantly over time. It is recommended that a miniscrew be loaded immediately; waiting a few weeks before loading should be avoided. The correlation between the ITV and RTV suggests that the ITV can be used to estimate a screw's future stability.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.4C
• /
• pp.276-282
• /
• 2005

These studies developed system as well as its algorithm which can measure traffic flow and vehicle speed on the highway as well as road by using industrial television(ITV) system. This algorithm used the real time processing of dynamic images. The processing algorithm of dynamic images is developed and proved its validity by frame grabber. Frame grabber can process the information of a small number of sample points only instead of the whole pixel of the images. In the techniques of this algorithm, we made approximate contour of vehicle by allocating sampling points in cross-direction of image, and recognized top of contour of vehicle. Applying these technique, we measured the number of passing vehicles of one lane as well as multilane. Speed of each vehicle is measured by computing the time difference between a pair of sample points on two sample Points lines.