Usefulness of a Small-Field Digital Mammographic Imaging System Using Parabolic Polycapillary Optics as a Diagnostic Imaging Tool: a Preliminary Study

천권수,박정곤,박성훈,강성훈,김혜원,손현화,김혜원,김헌수,윤권하 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.6

Objective: To evaluate the efficacy for spatial resolution and radiation dose of a small-field digital mammographic imaging system using parabolic polycapillary optics. Materials and Methods: We developed a small-field digital mammographic imaging system composed of a CCD (charge coupled device) detector and an Xray source coupled with parabolic polycapillary optics. The spatial resolution and radiation dose according to various filters were evaluated for a small-field digital mammographic imaging system. The images of a test standard phantom and breast cancer tissue sample were obtained. Results: The small-field digital mammographic imaging system had spatial resolutions of 12 lp/mm with molybdenum and rhodium filters with a 25-μm thickness. With a thicker molybdenum filter (100 μm thick), the system had a higher spatial resolution of 11 lp/mm and contrast of 0.48. The radiation dose for a rhodium filter with a 25-μm thickness was 0.13 mGy within a 10-mm-diameter local field. A larger field image greater than 10 mm in diameter could be obtained by scanning an object. On the small-field mammographic imaging system, microcalcifications of breast cancer tissue were clearly observed. Conclusion: A small-field digital mammographic imaging system with parabolic polycapillary optics may be a useful diagnostic tool for providing high-resolution imaging with a low radiation dose for examination of local volumes of breast tissue. Objective: To evaluate the efficacy for spatial resolution and radiation dose of a small-field digital mammographic imaging system using parabolic polycapillary optics. Materials and Methods: We developed a small-field digital mammographic imaging system composed of a CCD (charge coupled device) detector and an Xray source coupled with parabolic polycapillary optics. The spatial resolution and radiation dose according to various filters were evaluated for a small-field digital mammographic imaging system. The images of a test standard phantom and breast cancer tissue sample were obtained. Results: The small-field digital mammographic imaging system had spatial resolutions of 12 lp/mm with molybdenum and rhodium filters with a 25-μm thickness. With a thicker molybdenum filter (100 μm thick), the system had a higher spatial resolution of 11 lp/mm and contrast of 0.48. The radiation dose for a rhodium filter with a 25-μm thickness was 0.13 mGy within a 10-mm-diameter local field. A larger field image greater than 10 mm in diameter could be obtained by scanning an object. On the small-field mammographic imaging system, microcalcifications of breast cancer tissue were clearly observed. Conclusion: A small-field digital mammographic imaging system with parabolic polycapillary optics may be a useful diagnostic tool for providing high-resolution imaging with a low radiation dose for examination of local volumes of breast tissue.

Measurement of Roundness for an X-Ray Mono-Capillary Optic by Using Computed Tomography

천권수 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.9

X-ray computed tomography is a very useful tool for nondestructively imaging a cross section of a sample. By using a computed tomography beamline system of synchrotron radiation, we directly measured the radius of the inner reflection surface of a mono-capillary optic with an accuracy of 1.30~$\mu$m. The inner-surface deformation of a mono-capillary optic approximately 100 $\mu$m in diameter was first shown by combining radial profiles. The precise determination of the radius will contribute to an increase in fabrication precision for the mono-capillary optic.

Visualization and measurement of capillary-driven blood flow using spectral domain optical coherence tomography.

Cito, Salvatore,Ahn, Yeh-Chan,Pallares, Jordi,Duarte, Rodrigo Martinez,Chen, Zhongping,Madou, Marc,Katakis, Ioanis Springer-Verlag 2012 Microfluidics and Nanofluidics Vol.13 No.2

<P>Capillary-driven flow (CD-flow) in microchannels plays an important role in many microfluidic devices. These devices, the most popular being those based in lateral flow, are becoming increasingly used in health care and diagnostic applications. CD-flow can passively pump biological fluids as blood, serum or plasma, in microchannels and it can enhance the wall mass transfer by exploiting the convective effects of the flow behind the meniscus. The flow behind the meniscus has not been experimentally identified up to now because of the lack of high-resolution, non-invasive, cross-sectional imaging means. In this study, spectral-domain Doppler optical coherence tomography is used to visualize and measure the flow behind the meniscus in CD-flows of water and blood. Microchannels of polydimethylsiloxane and glass with different cross-sections are considered. The predictions of the flow behind the meniscus of numerical simulations using the power-law model for non-Newtonian fluids are in reasonable agreement with the measurements using blood as working fluid. The extension of the Lucas-Washburn equation to non-Newtonian power-law fluids predicts well the velocity of the meniscus of the experiments using blood.</P>

Usefulness of a Small-Field Digital Mammographic Imaging System Using Parabolic Polycapillary Optics as a Diagnostic Imaging Tool: a Preliminary Study

Chon, Kwon Su,Park, Jeong Gon,Son, Hyun Hwa,Kang, Sung Hoon,Park, Seong Hoon,Kim, Hye-won,Kim, Hun Soo,Yoon, Kwon-Ha The Korean Society of Radiology 2009 KOREAN JOURNAL OF RADIOLOGY Vol.10 No.6

<P><B>Objective</B></P><P>To evaluate the efficacy for spatial resolution and radiation dose of a small-field digital mammographic imaging system using parabolic polycapillary optics.</P><P><B>Materials and Methods</B></P><P>We developed a small-field digital mammographic imaging system composed of a CCD (charge coupled device) detector and an X-ray source coupled with parabolic polycapillary optics. The spatial resolution and radiation dose according to various filters were evaluated for a small-field digital mammographic imaging system. The images of a test standard phantom and breast cancer tissue sample were obtained.</P><P><B>Results</B></P><P>The small-field digital mammographic imaging system had spatial resolutions of 12 lp/mm with molybdenum and rhodium filters with a 25-µm thickness. With a thicker molybdenum filter (100 µm thick), the system had a higher spatial resolution of 11 lp/mm and contrast of 0.48. The radiation dose for a rhodium filter with a 25-µm thickness was 0.13 mGy within a 10-mm-diameter local field. A larger field image greater than 10 mm in diameter could be obtained by scanning an object. On the small-field mammographic imaging system, microcalcifications of breast cancer tissue were clearly observed.</P><P><B>Conclusion</B></P><P>A small-field digital mammographic imaging system with parabolic polycapillary optics may be a useful diagnostic tool for providing high-resolution imaging with a low radiation dose for examination of local volumes of breast tissue.</P>

망막정맥폐쇄환자에서 빛간섭단층혈관조영촬영 소견과 시력과의 연관성

Daruchi Moon,Ju Young Kim,Dong Kyu Lee,Jin Hae Lee,Oh Woong Kwon,Yong Sung You,Soon Hyun Kim,Hyun-Sub Oh 한국망막학회 2016 Journal of Retina Vol.1 No.2

Purpose: To describe optical coherence tomography angiography (OCTA) findings in retinal vein occlusion and to analyze their correlation with visual functions. Methods: Fluorescein angiography, optical coherence tomography and OCTA (RTVue XR Avanti with AngioVue, Optovue, Fremont, CA, USA) were performed. Qualitative analysis of the imaging data was performed. Results: Twenty-one eyes from 20 patients were included. On OCTA, characteristic findings of the involved areas were noted in the superficial plexus and the deep plexus. In the superficial plexus, telangiectasias were found in 2 out of 21 eyes (9.5%) and capillary dropout in 9 (42.8%). In the deep plexus, telangiectasias were found in 13 (61.9%) eyes, and capillary dropout in 13 (61.9%). All composites were found to be more common in the deep plexus than in the superficial plexus. Eyes with capillary dropout in the superficial plexus, which indicates ischemia, showed lower visual acuity compared with those without capillary dropout (p = 0.049). Conclusions: We were able to demonstrate that OCTA could visualize telangiectasias and capillary dropout in each retinal capillary layer. In particular, capillary dropout in the superficial capillary plexus was associated with visual impairment.

Investigation of heterogeneous of ellipsoid particle interaction field using optical laser tweezers

최규환,강동우,박범준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Heterogeneity among particles is their inherent feature, which makes the prediction of the properties of assembled structures and materials composed of many particles non-deterministic. Here, we report a promising strategy to quantify and visualize the field of heterogeneous and anisotropic interactions between non-spherical particles using the rotational measurement of optical laser tweezers. The mutual configuration and separation of two particles at an oil-water interface were optically controlled, and the corresponding capillary interaction behaviors were directly measured. As a result, the optimal particle configuration at an energetically favorable state was determined, depending on the interparticle distance. Visualization of the capillary field around individual particles demonstrated that the interface deformation by the presence of non-spherical particles and thus the capillary force were highly influenced by undulation of the meniscus as well as geodesic curvature.

Optical Microangiography: High-Definition Magnification Colonoscopy with Narrow Band Imaging (NBI) for Visualizing Mucosal Capillaries and Red Blood Cells in the Large Intestine

( Kenshi Yao ),( George K. Anagnostopoulos ),( Aida U. Jawhari ),( Philip V. Kaye ),( Chris J. Hawkey ),( Krish Ragunath ) 대한소화기기능성질환·운동학회 2008 Gut and Liver Vol.2 No.1

Background/Aims: Recent advances in zoom endoscopy have enabled the subepithelial capillary network (SECN) in different organs of the gastrointestinal tract to be visualized. Ex vivo studies have suggested that the SECN demonstrates a honeycomb-like structure in the large intestine, but this has not yet been visualized in vivo. The high clarity and resolution of narrow-band imaging (NBI) may allow visualization at the single red-blood-cell (RBC) level and more accurate visualization of the SECN. We investigated whether high-definition magnification colonoscopy with NBI is useful for visualizing capillaries and RBCs in the large intestine. Methods: Sixteen patients with bowel symptoms undergoing routine colonoscopy with normal findings in a tertiary referral academic gastroenterology and endoscopy unit were included in the study. Total colonoscopies were performed using a high-definition magnification colonoscope (CF-H260AZI, Olympus, Tokyo) and a prototype high-definition electronic endoscopy system capable of NBI. Each part of the large intestine (cecum, ascending, transverse, descending, and sigmoid colon, and rectum) was observed at the maximum magnification with white-light imaging (WLI) and NBI. The normal honeycomb-like SECN and RBC movement by high-definition magnification colonoscopy with either WLI or NBI was prospectively successfully visualized for each part of the large intestine. Results: In all subjects, high-definition magnification colonoscopy with NBI allowed the visualization of a honeycomb-like SECN together with RBC movement in each segment of the large intestine except for the rectum. In contrast, with WLI alone, neither this SECN structure nor RBC movement could be detected. Conclusions: High-definition magnification colonoscopy with NBI could be a new optical method for facilitating noninvasive investigations of both the microvascular architecture and microcirculation without the need for contrast materials. (Gut and Liver 2008; 2:14-18)

Improvement of Light Extraction Efficiency in Flip-Chip Light Emitting Diodes on SiC Substrate via Transparent Haze Films with Morphology-Controlled Collapsed Alumina Nanorods

Baek, Seunghwa,Kang, Gumin,Shin, Dongheok,Bae, Kyuyoung,Kim, Yong Hyun,Kim, Kyoungsik American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.1

<P>We demonstrate GaN-based flip-chip light emitting diodes (FC-LEDs) on SiC substrate achieving high extraction efficiency by simply attaching the optically transparent haze films consisting of collapsed alumina nanorods. Through controlled etching time of alumina nanorods, we obtain four types of films that have different morphologies with different optical transmittance and haze properties. We show that the light output power of the FC-LEDs with film, which has 95.6% transmittance and 62.7% haze, increases by 20.4% in comparison to the bare LEDs. The angular radiation pattern of the LEDs also follows the Lambertian emission pattern without deteriorating the electrical properties of the device. The improvement of light extraction is mainly attributed to the reduced total internal reflection (TIR) via efficient out-coupling of guided light from SiC substrate to air by collapsed alumina nanorod structures in the film. The high transparency of film and reduced Fresnel reflection via graded refractive index transition between the film and SiC substrate also contribute to the extraction enhancement of the device. We systematically investigate the influence of haze films geometrical or optical properties on the extraction efficiency of FC-LEDs, and this study will provide a novel approach to enhance the performance of various optoelectronic devices.</P>

Evaluation of Foveal Avascular Zone and Capillary Plexuses in Diabetic Patients by Optical Coherence Tomography Angiography

emine çiloğlu 대한안과학회 2019 Korean Journal of Ophthalmology Vol.33 No.4

Purpose: To investigate the foveal avascular zone (AVZ), superficial and deep foveal and parafoveal vesseldensity (VD) changes related to diabetic retinopathy. Methods: Forty-nine type 2 diabetes mellitus (DM) and 45 healthy control subjects were included in this study. The demographic data (age and sex), disease duration, and level of glycated hemoglobin were collected. SuperficialVD (%), superficial AVZ area (mm2), deep VD (%) and deep AVZ area (mm2) were evaluated via opticcoherence tomography angiography. Results: Superficial AVZ was 0.438 ± 0.05 mm2 in the DM group, 0.246 ± 0.022 mm2 in the control group (p< 0.001). Deep AVZ was 0.732 ± 0.06 mm2 in the DM group, and 0.342 ± 0.022 mm2 in the control group (p< 0.001). Superficial foveal VD was 29.45 ± 0.76 mm2 in the DM group, and 34.86 ± 0.75 mm2 in the controlgroup (p < 0.001). Deep foveal VD was 24.85 ± 1.08 mm2 in the DM group, and 33.47 ± 0.56 mm2 in the controlgroup (p < 0.001). Conclusions: In this study, we demonstrated an enlargement in the foveal AVZ along with a reduction in thevascular density of the superficial and deep capillary network in the foveal and parafoveal area using optic coherencetomography angiography in patients with nonproliferative diabetic retinopathy. This technique can beused to monitor the progression of the disease and to evaluate the response to treatment.

만성 비활성 망막분지정맥폐쇄의 빛간섭단층혈관조영 소견 특징

강민승(Min Seung Kang),이승민(Seung Min Lee),권한조(Han Jo Kwon) 대한안과학회 2021 대한안과학회지 Vol.62 No.6

목적: 만성 비활성 망막분지정맥폐쇄의 빛간섭단층혈관조영 결과를 정량 분석하고 그 특징을 알아보고자 하였다. 대상과 방법: 단안 허혈성 급성 망막분지정맥폐쇄로 진단되어 급성기 치료 이후 6개월 동안 재발하지 않은 48안의 의무기록을 후향적으로 분석하였다. 황반부 빛간섭단층혈관조영 영상으로부터 표층 및 심부모세혈관총 이상혈관영역과 심부모세혈관총 울혈영역을 분할한 후 각 영역의 면적, 혈관밀도, 망막평균두께를 측정하였다. 분할 영역의 빛간섭단층혈관조영 인자들과 기본 인자와의 연관성을 분석하였다. 결과: 평균 나이는 63.8세로 고혈압은 56.3%에서 동반되었다. 심부모세혈관총 이상혈관영역은 표층보다 모든 환자에서 넓게 측정되어(p<0.001) 그 사이 이행영역이 형성되었다. 심부모세혈관총 울혈영역은 2/3에서 이행영역에 분포하였고, 혈관밀도는 각 모세혈관총정상영역의 혈관밀도보다 높았으며(모두, p<0.001), 망막평균두께는 각 모세혈관총 이상혈관 영역보다 두꺼웠지만(모두, p<0.001) 정상혈관 영역과 차이가 없었다. 표층모세혈관총 이상영역에 심부모세혈관총 울혈영역이 더 많이 분포할수록 안정화 시점에 도달하는 주사 회수가 작았다(r=-0.314, p=0.030). 결론: 만성 비활성 망막분지정맥폐쇄의 심부모세혈관총 울혈은 혈관밀도가 높고 이행영역에 주로 분포하였다. 심부모세혈관총 울혈은 상승한 정맥내 압력에 대항하여 최소 저항으로 혈류를 배출하는 경로로 추정되며 이는 망막분지정맥폐쇄의 해부학적 안정성을 유지하는 데 중요한 역할을 하는 것으로 사료된다. Purpose: To investigate characteristics of optical coherence tomography angiography (OCTA) findings in chronic inactive branch retinal vein occlusion (BRVO) with quantitative analysis. Methods: The medical records of 48 eyes diagnosed with unilateral ischemic acute BRVO, and without recurrence for 6 months after the acute treatment, were reviewed retrospectively. We manually segmented the abnormal vessels of the superficial and deep capillary plexus (SCP-AV and DCP-AV, respectively) and vascular congestion of DCP (DCP-VC) from 6 × 6 mm2 macular OCTA images and automatically calculated the area, vessel density, and average retinal thickness of each corresponding region. Correlations were analyzed between the OCTA parameters of the segmentation area and the baseline characteristics. Results: The DCP-AV area was always wider than that of the SCP-AV (p < 0.001), with a transitional zone (TZ) between the two areas. About two-thirds of the DCP-VC area was distributed in the TZ. The vessel density of the DCP-VC was higher than that of the normal capillary plexus (all, p < 0.001). The average retinal thickness of the DCP-VC was greater than those of SCP-AV and DCP-AV areas (all, p < 0.001), but not different from the normal capillary plexus. The greater the extent of the DCP-VC distribution under the SCP-AV, the fewer the number of injections required to reach stabilization (r = -0.314, p = 0.030). Conclusions: DCP-VC in chronic inactive BRVO was mainly distributed in the TZ with high vessel density. DCP-VC seems to provide a drainage pathway with minimal resistance against elevated intravenous pressure, which may sustain the anatomical stability of chronic BRVO.