• Imaging Science in Dentistry
• /
• 제36권4호
• /
• pp.189-198
• /
• 2006

Purpose: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT). Materials and Methods: The MC3T3-E1 cells were cultured in an ${\alpha}-MEM$ supplemented with 5 mM 2-DG or $10{\mu}M$ QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization. Results: Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5-diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level. Conclusion: The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radiosensitizing agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.

• 대한한방부인과학회지
• /
• 제19권3호
• /
• pp.203-213
• /
• 2006

Purpose : This study was carried out to evaluate correlation between Bone Mineral Density(BMD) and degenerative lumbar disease in postmenopausal low back pain patients. Methods : 69 postmenopausal patients with low back pain were examined. Magnetic resonance imaging was performed to evaluate degenerative lumbar disease and bone mineral density of lumbar spine was measured by Dual energy X-ray absorptiometry. Data were analyzed by Pearson's Linear Correlation Coefficient. Results : In postmenopausal patients with low back pain, BMD(T-score, Z-score) had negative correlation with the grade of intervertebral disc herniation and positive correlation with weight. Other lumbar diseases including Spinal stenosis, Spondylolisthesis and Facet joint arthrosis didn't have significant correlation with BMD. Conclusion : In postmenopausal patients with low back pain, BMD(T-score, Z-score) had inverse relationship with the grade of intervertebral disc herniation.

• Nuclear Engineering and Technology
• /
• 제55권2호
• /
• pp.655-668
• /
• 2023

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moiré components while minimizing the loss of image information and apply the prior information of Moiré component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flat-panel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 × 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm × 24 cm, line density: 103 LP/inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.

• 대한방사선기술학회지:방사선기술과학
• /
• 제37권2호
• /
• pp.93-100
• /
• 2014

최근 무선 LAN통신 기능을 이용하여 보다 간편하고 빠르게 디지털 방사선 영상을 획득할 수 있는 디지털 무선 이동촬영장치가 개발되어 많은 편의성을 제공하고 있다. 응급 또는 중환자를 대상으로 시행하는 이동촬영(Portable)검사 특성상 발생할 수 있는 초점-격자 간 중심변위와 피사체의 검출기내 위치변위가 영상화질에 미치는 영향을 평가하여 디지털 무선 검출기의 가이드라인을 제시하고자 한다. 본 연구에서 사용된 장비는 Elmo-T6 Digital Mobile X선시스템(SIMAZU사), el' Tor($14{\times}17$"Wireless detector), 격자(10:1), Chest & head phantom을 사용하였다. 선량증가에 따른 후처리 영상과 초점-격자 간 중심변위와 두부팬텀의 위치변위 영상을 획득한 후 디지털 영상분석 프로그램 Image J를 사용하여 영상을 비교분석 평가하였다. 선량증가에 따른 영상의 변화에서 0.5 mAs의 선량에서는 영상이 거칠고, 적정선량인 1~2 mAs에서 시각적으로 영상의 차이를 알 수 없었고, 특히 2.5 mAs 부터 픽셀 평균값이 급격히 감소하여 대조도에 영향을 미치는 것으로 나타났다. 3 mAs 이상에서는 폐부분의 포화현상으로 대조도가 떨어졌다. Image J 프로그램을 이용한 분석결과 초점-격자 간과 두부팬텀의 중심의 위치변위가 커질수록 낮은 픽셀값의 빈도수가 증가하여 표면도의 윤곽형태가 사라져 대조도에 영향을 미치는 것으로 나타났다. 중환자의 특성상 환자 자세의 어려움, 움직임, 호흡 및 X선관의 변위, 촬영거리의 적용여부에 따라 영상화질을 변화시킬 수 있다는 사실을 방사선사는 정확히 인지하여 검사에 임해야 할 것으로 사료된다.

• Journal of Korean Neurosurgical Society
• /
• 제37권4호
• /
• pp.313-315
• /
• 2005

A 66 year-old woman was admitted to our hospital for progressive weakness of both lower extremities since a month ago. Imaging study, based on plain X-ray, computed tomography and magnetic resonance image revealed spinal stenosis owing to anterior slipping of T10/11 segment. Degenerative spondylolisthesis is common in the lumbar spine and rarely occurs in the cervical spine. But there was no report of degenerative spondylolisthesis in thoracic spine. The authors experienced a case of degenerative spondylolisthesis in the thoracic spine. And we achieved a satisfactory result with posterior decompressive laminectomy alone.

• 센서학회지
• /
• 제30권5호
• /
• pp.342-348
• /
• 2021

For the characterization or failure analysis of electronic devices such as PCB (printed circuit boards), the most common method is the measurement of voltage waveforms with an oscilloscope. However, because there are many types of problems that cannot be detected by voltage waveform analysis, several other methods such as X-ray transmission, infrared imaging, or eddy current measurement have been applied for these analyses. However, these methods have also been limited to general analyses because they are partially useful in detecting physical defects, such as disconnections or short circuits. Fundamentally current waveform measurements during the operation of electronic devices need to be performed, however, commercially available current sensors have not yet been developed, particularly for applications in highly integrated PCB products with sub-millimeter fine pitch. In this study, we developed a highly sensitive PHR (planar hall resistance) magnetic sensor for application in highly integrated PCBs. The developed magnetic sensor exhibited sufficient features of an ultra-small size of less than 340 ㎛, magnetic field resolution of 10 nT, and current resolution of 1 mA, which can be applicable for PCB analyses. In this work, we introduce the development process of the magnetic sensing probe and its characteristic results in detail, and aim to extend this pin-type current probe to applications such as current distribution imaging of PCBs.

• Progress in Superconductivity
• /
• 제14권2호
• /
• pp.82-86
• /
• 2012

A sensitive eight-channel high-Tc Superconducting Interference Device (SQUID) detection system for magnetic contaminant in a lithium ion battery anode was developed. Finding ultra-small metallic foreign matter is an important issue for a manufacturer because metallic contaminants carry the risk of an internal short. When contamination occurs, the manufacturer of the product suffers a great loss from recalling the tainted product. Metallic particles with outer dimensions smaller than 100 microns cannot be detected using a conventional X-ray imaging system. Therefore, a highly sensitive detection system for small foreign matter is required. We have already developed a detection system based on a single-channel SQUID gradiometer and horizontal magnetization. For practical use, the detection width of the system should be increased to at least 65 mm by employing multiple sensors. In this paper, we present an 8-ch high-Tc SQUID roll-to-roll system for inspecting a lithium-ion battery anode with a width of 65 mm. A special microscopic type of a cryostat was developed upon which eight SQUID gradiometers were mounted. As a result, small iron particles of 35 microns on a real lithium-ion battery anode with a width of 70 mm were successfully detected. This system is practical for the detection of contaminants in a lithium ion battery anode sheet.

• Investigative Magnetic Resonance Imaging
• /
• 제19권2호
• /
• pp.76-87
• /
• 2015

Purpose: There is an ongoing search for a stent material that produces a reduced susceptibility artifact. This study evaluated the effect of manganese (Mn) content on the MRI susceptibility artifact of ferrous-manganese (Fe-Mn) alloys, and investigated the correlation between MRI findings and measurements of Fe-Mn microstructure on X-ray diffraction (XRD). Materials and Methods: Fe-Mn binary alloys were prepared with Mn contents varying from 10% to 35% by weight (i.e., 10%, 15%, 20%, 25%, 30%, and 35%; designated as Fe-10Mn, Fe-15Mn, Fe-20Mn, Fe-25Mn, Fe-30Mn, and Fe-35Mn, respectively), and their microstructure was evaluated using XRD. Three-dimensional spoiled gradient echo sequences of cylindrical specimens were obtained in parallel and perpendicular to the static magnetic field (B0). In addition, T1-weighted spin echo, T2-weighted fast spin echo, and $T2^*$weighted gradient echo images were obtained. The size of the low-intensity area on MRI was measured for each of the Fe-Mn binary alloys prepared. Results: Three phases of ${\alpha}^{\prime}$-martensite, ${\gamma}$-austenite, and ${\varepsilon}$-martensite were seen on XRD, and their composition changed from ${\alpha}^{\prime}$-martensite to ${\gamma}$-austenite and/or ${\varepsilon}$-martensite, with increasing Mn content. The Fe-10Mn and Fe-15Mn specimens comprised ${\alpha}^{\prime}$-martensite, the Fe-20Mn and Fe-25Mn specimens comprised ${\gamma}+{\varepsilon}$ phases, and the Fe-30Mn and Fe-35Mn specimens exhibited a single ${\gamma}$ phase. The size of the low-intensity areas of Fe-Mn on MRI decreased relative to its microstructure on XRD with increasing Mn content. Conclusion: Based on these findings, proper conditioning of the Mn content in Fe-Mn alloys will improve its visibility on MR angiography, and a Mn content of more than 25% is recommended to reduce the magnetic susceptibility artifacts on MRI. A reduced artifact of Fe-Mn alloys on MRI is closely related to the paramagnetic constitution of ${\gamma}$-austenite and/or ${\varepsilon}$-martensite.

• 대한영상의학회지
• /
• 제83권2호
• /
• pp.439-443
• /
• 2022

갈색지방종은 갈색지방조직의 드문 양성 종양이다. 저자들은 53세 여자 환자에서 액와부 갈색지방종의 다양한 영상 소견을 보고하고자 한다. 초음파에서 오른쪽 액와부에 4.5 cm의 경계가 분명한 타원형의 비균질한 고에코의 종괴였으며, 액와부 혈관들을 앞쪽으로 전위시키고 있었다. 조영 전 흉부 단층촬영에서 5 cm의 경계가 분명한 타원형의 저감쇠의 종괴로 보였다. 자기공명영상에서는 T1과 T2 강조영상에서 비균질한 중간 및 고신호강도의 5.5 cm 종괴였으며, 변연부에서 불규칙한 조영증강을 보였다. 환자는 초음파유도중심부바늘생검을 받아 최종적으로 갈색지방종으로 진단되었다.

• 대한영상의학회지
• /
• 제82권5호
• /
• pp.1334-1340
• /
• 2021

아밀로이드증과 비호지킨림프종과의 연관관계는 이전의 연구들에서 보고된 바 있다. 림프종과 아밀로이드증과의 연관관계는 두 개의 구분되는 범주로 나뉘는데 림프종 연관 전신성 아밀로이드증과 종괴 주위 아밀로이드증이다. 저자들은 두경부 MALT 림프종 환자에서 발생한 국소적 종괴 주위 아밀로이드증의 드문 증례를 보고하고자 한다. 전산화단층촬영에서 병변은 연조직음영을 보이는 무정형석회화를 동반한 불규칙한 모양의 종괴였으며, 조영증강 시 불균일한 조영증강을 보였다. 자기공명영상에서는 종괴가 T1 강조영상과 T2 강조영상에서 모두 불균일한 낮은 신호 강도를 보였다. 종괴는 강한 조영증강을 보였으며, 내부에는 여러 개의 조영증강되지 않는 부분들을 포함하고 있었다. 림프종 환자에서 치료 전 영상검사에서 발견된 석회화들은 종괴 주위 아밀로이드증과 같은 동반된 다른 이차성 병변을 시사하는 소견이 될 수 있을 것이다.