• Korean Journal of Radiology
• /
• 제25권2호
• /
• pp.157-165
• /
• 2024

Objective: We aimed to evaluate the clinical and imaging factors associated with hemorrhagic complications and patient discomfort following ultrasound (US)-guided breast biopsy. Materials and Methods: We prospectively enrolled 94 patients who were referred to our hospital between June 2022 and December 2022 for US-guided breast biopsy. After obtaining informed consent, two breast radiologists independently performed US-guided breast biopsy and evaluated the imaging findings. A hemorrhagic complication was defined as the presence of bleeding or hematoma on US. The patients rated symptoms of pain, febrile sensation, swelling at the biopsy site, and dyspnea immediately, 20 minutes, and 2 weeks after the procedure on a visual analog scale, with 0 for none and 10 for the most severe symptoms. Additional details recorded included those of nausea, vomiting, bleeding, bruising, and overall satisfaction score. We compared the clinical symptoms, imaging characteristics, and procedural features between patients with and those without hemorrhagic complications. Results: Of 94 patients, 7 (7%) developed hemorrhagic complications, while 87 (93%) did not. The complication resolved with 20 minutes of manual compression, and no further intervention was required. Vascularity on Doppler examination (P = 0.008), needle type (P = 0.043), and lesion location (P < 0.001) were significantly different between the groups. Patients with hemorrhagic complications reported more frequent nausea or vomiting than those without hemorrhagic complications (29% [2/7] vs. 2% [2/87], respectively; P = 0.027). The overall satisfaction scores did not differ between the two groups (P = 0.396). After 2 weeks, all symptoms subsided, except bruising (50% 2/4 in the complication group and 25% [16/65] in the no-complication group). Conclusion: US-guided breast biopsy is a safe procedure with a low complication rate. Radiologists should be aware of hemorrhagic complications, patient discomfort, and overall satisfaction related to this procedure.

• 천문학회보
• /
• 제37권1호
• /
• pp.86.2-86.2
• /
• 2012

We present the study of association between sub-photospheric flow and photospheric magnetic fields of active regions respectively derived from the local helioseismology and observed magnetic fields. It is believed that the energetic transients, e.g., flares and CMES, are caused by changes in magnetic and velocity field topologies in solar atmosphere. These changes are essentially brought about by the magnetic fields that are rooted beneath the photosphere where they interact and get affected by sub-photospheric flows. Therefore, we expect the topology of sub-surface flows to be correlated with the observable topology of magnetic fields at the photosphere and higher layers. In order to examine the correlation, if any, we computed the near photospheric flows and photospheric magnetic fields using the Doppler velocity and magnetic fields observations, respectively, provided by the SDO/HMI. The high resolution Doppler observations from the HMI enabled us to compute the very high p-modes parameters which sample the sub-photosphere shallow near the photosphere. Furthermore, we compute the sub-photospheric flow topology parameters, e.g., vorticity, kinetic helicity, and photospheric magnetic field topology parameters, e.g., magnetic helicity, from the magnetic fields observations to compare their associations. We present the result of the analysis in the paper.

• 한국정밀공학회지
• /
• 제19권9호
• /
• pp.172-178
• /
• 2002

One of the ever-increasing demands on the performances of heterodyne interferometers is to improve the measurement resolution, of which current state -of-the-art reaches the region of sub-nanometers. So far, the demand has been met by increasing the clock speed that drives the electronics involved fur the phase measurement of the Doppler shift, but its further advance is being hampered by the technological limit of modem electronics. To cope with the problem, in this investigation, we propose a new scheme of phase -measuring electronics that reduces the measurement resolution without further increase in clock speed. Our scheme adopts a super-heterodyne technique that lowers the original beat frequency to a level of 1 MHz by mixing it with a stable reference signal generated from a special phase- locked-loop. The technique enables us to measure the phase of Doppler shift with a resolution of 1.58 nanometer at a sampling rate of 1 MHz. To avoid the undesirable decrease in the maximum measurable speed caused by the lowered beat frequency, a special form of frequency up-down counting technique is combined with the super-heterodyning. This allows performing required phase unwrapping simply by using programmable digital gates without 2n ambiguities up to the maximum velocity guaranteed by the original beat frequency.

• 대한영상의학회지
• /
• 제81권2호
• /
• pp.395-408
• /
• 2020

목적 유방암 일차치료 후 조기 재발 예측에 도움이 되는 임상병리학적 인자 및 원발암의 영상의학적 특징을 알아보고자 하였다. 대상과 방법 본원에서 2010년 1월부터 2014년 12월까지 유방 보존 수술 및 보조요법 치료 후 추적관찰을 받은 480명을 대상으로 하였다. 일차치료 완결 후 3년 이내 재발한 경우를 조기재발으로 정의하고, 이와 관련된 임상병리학적 및 영상의학적 예측인자를 알아보기 위해 단변량 및 다변량 로지스틱 회귀분석을 시행하였다. 결과 단변량 분석에서 임상병리학적 인자 중 높은 종양 병기(p = 0.021), 고등급 조직학적 분화도(p < 0.001), estrogen receptor 수용체 음성(p = 0.002), Ki-67 과발현(p = 0.017), 삼중음성유방 아형(p = 0.019)과, 영상 소견 중 유방암의 다초점성(p < 0.001), 도플러 검사에서 테두리 혈류(p = 0.012), 자기공명영상에서 테두리 조영증강(p < 0.001)이 조기 재발과 유의한 연관성을 보였다. 다변량 분석에서 원발암의 높은 종양 병기[odds ratio (이하 OR) = 3.47, 95% confidence interval (이하 CI) 1.12~10.73, p = 0.031]와 도플러 검사에서 테두리 혈류 (OR = 3.32, 95% CI 1.38~8.02,p = 0.008)가 조기 재발과 관련된 독립적인 예측인자였다. 결론 유방암 치료 전 도플러 검사에서 원발암의 테두리 혈류 소견은 유방암의 일차치료 후 조기 재발의 독립적인 영상의학적 예측인자이다.

• Korean Journal of Radiology
• /
• 제20권5호
• /
• pp.759-772
• /
• 2019

Objective: To investigate the value of ultrasound (US) microflow assessment in distinguishing malignant from benign solid breast masses as well as the association between US parameters and histologic microvessel density (MVD). Materials and Methods: Ninety-eight breast masses (57 benign and 41 malignant) were examined using Superb Microvascular Imaging (SMI) and contrast-enhanced US (CEUS) before biopsy. Two radiologists evaluated the quantitative and qualitative vascular parameters on SMI (vascular index, morphology, distribution, and penetration) and CEUS (time-intensity curve analysis and enhancement characteristics). US parameters were compared between benign and malignant masses and the diagnostic performance was compared between SMI and CEUS. Subgroup analysis was performed according to lesion size. The effect of vascular parameters on downgrading Breast Imaging Reporting and Data System (BI-RADS) category 4A masses was evaluated. The association between histologic MVD and US parameters was analyzed. Results: Malignant masses were associated with a higher vascular index (15.1 ± 7.3 vs. 5.9 ± 5.6), complex vessel morphology (82.9% vs. 42.1%), central vascularity (95.1% vs. 59.6%), penetrating vessels (80.5% vs. 31.6%) on SMI (all, p < 0.001), as well as higher peak intensity (37.1 ± 25.7 vs. 17.0 ± 15.8, p < 0.001), slope (10.6 ± 11.2 vs. 3.9 ± 4.2, p = 0.001), area (1035.7 ± 726.9 vs. 458.2 ± 410.2, p < 0.001), hyperenhancement (95.1% vs. 70.2%, p = 0.005), centripetal enhancement (70.7% vs. 45.6%, p = 0.023), penetrating vessels (65.9% vs. 22.8%, p < 0.001), and perfusion defects (31.7% vs. 3.5%, p < 0.001) on CEUS (p ≤ 0.023). The areas under the receiver operating characteristic curve (AUCs) of SMI and CEUS were 0.853 and 0.841, respectively (p = 0.803). In 19 masses measuring < 10 mm, central vascularity on SMI was associated with malignancy (100% vs. 38.5%, p = 0.018). Considering all benign SMI parameters on the BI-RADS assessment, unnecessary biopsies could be avoided in 12 category 4A masses with improved AUCs (0.500 vs. 0.605, p < 0.001). US vascular parameters associated with malignancy showed higher MVD (p ≤ 0.016). MVD was higher in malignant masses than in benign masses, and malignant masses negative for estrogen receptor or positive for Ki67 had higher MVD (p < 0.05). Conclusion: US microflow assessment using SMI and CEUS is valuable in distinguishing malignant from benign solid breast masses, and US vascular parameters are associated with histologic MVD.

• Annals of Clinical Neurophysiology
• /
• 제1권1호
• /
• pp.26-30
• /
• 1999

본 연구에서는 ERP검사 중에는 중뇌동맥의 MFV가 검사전후와 비교하여 유의하게 증가힌 소견을 보였다. 비록 중뇌동맥의 혈류속도의 변화가 뇌활동정도를 직접 반영할 수는 없다고 생각이 되지만 이 연구의 결과로 P300의 생성에 중뇌동맥에 의해서 영양받는 전두엽, 측두엽 및 두정엽이나 다른 대뇌부위가 관여할 것으로 사료된다. 경두개도플러검사는 다른 뇌기능활동을 반영할 수 있는 양전자방출단층촬영이나 단일광자방출단층촬영과 같이 혈류역학을 볼 수 있는 검사와 병행하여 연구하면 P300의 발생부위를 규명하는데 도움을 줄 것으로 사료되며 뇌활동을 역동적으로 평가하는데 도움을 줄 것으로 생각된다.

• 대한한의학회지
• /
• 제17권1호
• /
• pp.345-360
• /
• 1996

Background and Purpose: To evaluate the blood flow velocity using doppler ultrasound of the carotid artery, vertebral artery, and basilar artery in stroke patients Material and Methods: To evaluate the blood flow, I measured the peak systolic velocity and mean velocity of the common carotid artery(CCA), internal carotid artery(ICA), external carotid artery (ECA). vertebral artery(VA), and basilar artery(BA) in 44 stroke patients and 15 healthy adults. To investigate the difference between ischemic stroke patients and normal healthy adults, I selected 44 ischemic stroke patients diagnosed by brain CT and brain MRI, and 15 healthy adults who did not have any symptoms of stroke, hypertension, heart disease, and diabetes melitus. Results: Peak velocity in normal adults was 50.6${\pm}$1.6cm/sec in the CCA, 67.2${\pm}$1.7cm/sec in the ICA, 62.5${\pm}$2.4cm/see in the ECA, 45.5${\pm}$1.9cm/sec VA. and 50.5${\pm}$3.5cm/sec in the BA. Mean velocity in normal adults was 26.9${\pm}$1.1cm/sec in the CCA, 43.7${\pm}$1.4cm/sec in the ICA, 26.7${\pm}$1.3cm/sec in the ECA. 31.6${\pm}$1.9cm/sec in the VA and 33.0${\pm}$2.6cm/sec in the BA. In this study, there was a significant increase in the velocity of ICA, ECA, and VA of ischemic stroke patients in comparison with normal healthy adults. And the blood flow velocity of this study in the CCA and ECA was different from other reported foreign values and the other known values in my country. Conclusion: There was a significant difference in the blood flow velocity between ischemic stroke patients and normal healthy adults. And the blood flow velocity of this study was different from other reported foreign values and the other known values in my country. Therefore, it needs more detailed studies about old aged Korean and ischemic stroke patients than previous studies.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 춘계학술대회 논문집
• /
• pp.203-206
• /
• 2002

One of the ever-increasing demands on the performances of heterodyne interferometers is to improve the measurement resolution, of which current state-of-the-art reaches the region of sub-nanometers. We propose a new scheme of phase-measuring electronics that reduces the measurement resolution without further increase in clock speed. Our scheme adopts a super-heterodyne technique that lowers the original beat frequency to a level of 1 MHz by mixing it with electrically generated reference signal. The technique enables us to measure the phase of Doppler shift with a resolution of 1.58 nanometer at a sampling rate of 1 MHz. To avoid the undesirable decrease in the maximum measurable speed caused by the lowered beat frequency, a special from of frequency up-down counting technique is combined with the super-heterodyning. This alloys performing required phase unwrapping simply by using programmable digital gates without 2$\pi$ ambiguities up to the maximum velocity of 2.35 m/s.

• 대한영상의학회지
• /
• 제84권3호
• /
• pp.676-685
• /
• 2023

목적 본 연구는 무증상 여성의 유방 초음파에서 발견된 군집 미세낭종의 발생률, 임상적 결과 및 영상 소견을 알아보고, 적절한 조치 가이드라인을 제시하고자 한다. 대상과 방법 2014년 8월부터 2019년 12월까지 무증상 여성에서 시행한 유방 초음파에서 발견된 군집 미세낭종 병변에 대해 분석하였다. 최종 진단은 병리학적 결과 및 12개월 이상의 추적관찰로 하였다. 결과 100명의 환자에서 117개 병변이 후향적으로 연구되었으며, 군집 미세낭종의 발생률은 1.5%였다. 총 117개의 병변 중, 3개(2.6%)는 악성, 2개(1.7%)는 고위험 병변, 112개(95.7%)는 양성이었다. 악성 병변 중 2개는 관상피내암이었고, 1개는 침윤성 유관암이었다. 이중, 유방 촬영술에서 의심스러운 미세석회화 또는 초음파에서 내부 혈류를 보인 2개의 병변은 category 4로 분류되었다. 나머지는 12개월 뒤 시행한 초음파에서 echo pattern의 변화를 보인 위 음성의 증례였다. 결론 무증상 여성에서 시행한 유방 초음파에서 군집 미세낭종의 유병률은 1.5%였으며, 악성률은 2.6%였다. 군집 미세낭종의 악성률과 양성 및 악성 영상 소견을 아는 것은 영상의학과 의사들이 병변을 분류하고 적절한 조치를 권유하는 데 도움이 될 것이다.

• 대한조선학회논문집
• /
• 제54권6호
• /
• pp.515-521
• /
• 2017

Large Cavitation Tunnel (LCT) of KRISO enables us to conduct cavitation tests of the propeller attached to a ship model. As the ship model tests are done at rather high Reynolds number of 107~108, flow measurement system such as pitot tube cannot be employed because of structural safety problems in its system and difficulties in installing it within the test section. Thus, KRISO has developed new 3-D LDV system used in large test section of LCT. There are several difficulties in using 3-D LDV, which did not allow efficient operation of it. The first trouble was the calibration using the conventional pin hole. To make the focus with same laser-beam waists at the wanted position, the high spatial resolution CCD is utilized in the calibration procedure for 3-D LDV. The off-axis configuration provides two velocity components in the horizontal plane and on-axis configuration gives third velocity component in the vertical plane. The horizontal velocity components are also obtained in the coincidence mode, which prevents any misleading results in the off-axis configuration. The nominal wake of Aframax tanker model is measured by the developed 3-D LDV system. The measured hull wake showed good agreement with that obtained by CFD calculation.