• Journal of Magnetics
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• 제19권3호
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• pp.261-265
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• 2014

Three-dimensional computed tomography is an effective tool to estimate the liver volume of living donors for the live liver transplantation. When additional operation is required, magnetic resonance imaging is conducted to determine the safety of the donor. This study compared the accuracy of magnetic resonance imaging and computed tomography in estimating 3D liver volume of 23 male and 7 female donors who underwent both magnetic resonance imaging and computed tomography tests before the transplantation. The analysis was conducted to see whether the liver's estimated total volumes and the left lobe volumes obtained from 3D-magnetic resonance imaging and 3D-computed tomography were identical. Volumes of the right lobe estimated with 3D-magnetic resonance imaging and 3D-computed tomography were compared with the actual volume of the right lobe harvested in the operating room because the volume of the right lobe is an important determinant in the safety of the donor. The total volume of the liver estimated from 3D-magnetic resonance imaging and 3D-computed tomography differed (1238.1904 units and 1402.364 units respectively). The left lobe volume of the liver estimated with 3D-magnetic resonance imaging and 3D-computed tomography also differed (450.530 units and 554.490 units, respectively). The right lobe volume of the liver estimated with 3D-magnetic resonance imaging and 3D-computed tomography were 787.660 units and 847.545 units, respectively, while the actual average right lobe volume of the harvested liver was 678.636 units. 3D-computed tomography has been widely used to estimate the right lobe volume of the donors' liver. However, 3D-magnetic resonance imaging was also very effective in estimating the volume of the liver. Thus, 3D-magnetic resonance imaging is also expected to become an important tool in determining the safety of the donors before transplantation.

• 스마트미디어저널
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• 제9권2호
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• pp.22-32
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• 2020

The hippocampal volume atrophy is known to be linked with neuro-degenerative disorders and it is also one of the most important early biomarkers for Alzheimer's disease detection. The measurements of hippocampal pure volumes from Magnetic Resonance Imaging (MRI) is a crucial task and state-of-the-art methods require a large amount of time. In addition, the structural brain development is investigated using MRI data, where brain morphometry (e.g. cortical thickness, volume, surface area etc.) study is one of the significant parts of the analysis. In this study, we have proposed a patch-based ensemble model of 3-D convolutional neural network (CNN) to measure the hippocampal pure volume from MRI data. The 3-D patches were extracted from the volumetric MRI scans to train the proposed 3-D CNN models. The trained models are used to construct the ensemble 3-D CNN model and the aggregated model predicts the pure volume in one-step in the test phase. Our approach takes only 5 seconds to estimate the volumes from an MRI scan. The average errors for the proposed ensemble 3-D CNN model are 11.7±8.8 (error%±STD) and 12.5±12.8 (error%±STD) for the left and right hippocampi of 65 test MRI scans, respectively. The quantitative study on the predicted volumes over the ground truth volumes shows that the proposed approach can be used as a proxy.

• Archives of Plastic Surgery
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• 제43권5호
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• pp.430-437
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• 2016

Background Accurate breast volume assessment is a prerequisite to preoperative planning, as well as intraoperative decision making in breast reconstruction surgery. The use of three-dimensional surface imaging (3D scanning) to assess breast volume has many advantages. However, before employing 3D scanning in the field, the tool's validity should be demonstrated. The purpose of this study was to confirm the validity of 3D-scanning technology for evaluating breast volume. Methods We reviewed the charts of 25 patients who underwent breast reconstruction surgery immediately after total mastectomy. Breast volumes using the Axis Three 3D scanner, water-displacement technique, and magnetic resonance imaging (MRI) were obtained bilaterally in the preoperative period. During the operation, the tissue removed during total mastectomy was weighed and the specimen volume was calculated from the weight. Then, we compared the volume obtained from 3D scanning with those obtained using the water-displacement technique, MRI, and the calculated volume of the tissue removed. Results The intraclass correlation coefficient (ICC) of breast volumes obtained from 3D scanning, as compared to the volumes obtained using the water-displacement technique and specimen weight, demonstrated excellent reliability. The ICC of breast volumes obtained using 3D scanning, as compared to those obtained by MRI, demonstrated substantial reliability. Passing-Bablok regression showed agreement between 3D scanning and the water-displacement technique, and showed a linear association of 3D scanning with MRI and specimen volume, respectively. Conclusions When compared with the classical water-displacement technique and MRI-based volumetry, 3D scanning showed significant reliability and a linear association with the other two methods.

• 한국ITS학회 논문지
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• 제7권5호
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• pp.180-183
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• 2008

본 논문은 교통망에서 관측 링크 교통량, 미관측 링크의 이용자평형 정보를 이용하여 O-D행렬을 수학적으로 생성하는 모형을 제시하고 있다. 교통량이 관측되지 않은 링크로부터 이용자 평형 상태에서 추출 가능한 정보를 바탕으로 일련의 논리적 연산을 거쳐 실제교통량에 근접하는 서브알고리듬을 유추하여 O-D행렬 추정의 정확도와 연산의 일관성을 제고하였다. 이를 위해 이용자평형상태에서 새로운 정리(Theorem)와 보조정리(Lemma)를 유도하여 적용하였다. 모형의 시험은 3개의 초기 O-D 행렬과 3개의 미관측 링크 교통량 시나리오를 각각의 모형에 적용하여 그 결과를 비교하였다. 적용 결과 본 논문에서 제시된 모형은 기존의 이용자균형 접근방식의 모형emf에 비해 추정된 O-D값의 실제 값과의 차이(O-D Trip RMSE)가 현저히 감소되는 것을 확인하였다.

• The Korean Journal of Ecology
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• 제26권3호
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• pp.123-127
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• 2003

Cubic-meter volumes estimated from two proxy taper functions were compared to observed volumes of Japanese red cedar trees (Cryptomeria japonica D. Don) to evaluate accuracy and precision in the centroid method. Centroid volume estimates were also compared to volume estimates from existing whole-tree volume equations developed for another geographic region. This study found that one proxy function produced unbiased volume estimates while the other was biased. Volume estimates from the whole-tree equations were also biased. However, the volume estimates from the whole-tree equations were more precise than those from the centroid method. These results support previous studies that the centroid method can produce reliable volumes of trees when no other reliable volume equations exist.

• 한국지능시스템학회논문지
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• 제24권5호
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• pp.518-528
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• 2014

본 논문에서는 4차원 시공간 (4D-ST, [x,y,z,t]) 특징을 이용하여 행동 방향을 인식하는 방법을 제안한다. 이를 위해 4차원 시공간 특징점 (4D-STIPs, [x,y,z,t])을 제안하였고, 이는 여러 다른 뷰에서 촬영한 이미지들로부터 복원된 3차원 공간 (3D-S, [x,y,z]) 볼륨으로부터 계산된다. 3차원 공간정보를 갖고 있는 3D-S 볼륨과 4D-STIPs는 2차원 공간 (2D-S, [x,y]) 뷰로 사영을 하여 임의의 2D-S 뷰에서의 특징을 생성해 낼 수 있다. 이 때, 사영 방향을 결정 할 수 있으므로, 학습 시 방향에 대한 정보를 포함하여 행동 방향을 인식 할 수 있다. 행동 방향을 인식하는 과정은 두 단계로 나눌 수 있는데, 우선 어떤 행동인지를 인식하고 그 후, 방향 정보를 이용하여 최종적으로 행동 방향을 인식한다. 행동 인식과 방향 인식을 위해, 사영된 3D-S 볼륨과 4D-STIPs은 각각 움직이는 부분과 움직이지 않는 부분에 대한 정보를 담고 있는 motion history images (MHIs)와 non-motion history images (NMHIs)로 구성된다. 이러한 특징들은 행동 인식을 위해, 방향 정보에 상관없이 같은 행동이면 같은 클래스로 분류되어 support vector data description (SVDD) 분류기로 학습되고, support vector domain density description (SVDDD)을 이용하여 인식된다. 인식된 행동에서 최종적으로 방향을 인식하기 위해 각 행동을 방향 클래스로 분류하여 SVDD 분류기로 학습하고 SVDDD로 인식한다. 제안된 방법의 성능을 보이기 위해서 INRIA Xmas Motion Acquisition Sequences (IXMAS) 데이터셋에서 제공하는 3D-S 볼륨을 사용하여 학습을 하고, 행동 방향 인식 실험이 가능한 SNU 데이터셋을 구축하여 인식 실험을 하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4727-4732
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• 2014

Background: Breast cancers are becoming more frequently diagnosed at early stages with improved long term outcomes. Late normal tissue complications induced by radiotherapy must be avoided with new breast radiotherapy techniques being developed. The aim of the study was to compare dosimetric parameters of planning target volume (PTV) and organs at risk between conformal (CRT) and intensity-modulated radiation therapy (IMRT) after breast-conserving surgery. Materials and Methods: A total of 20 patients with early stage left breast cancer received adjuvant radiotherapy after conservative surgery, 10 by 3D-CRT and 10 by IMRT, with a dose of 50 Gy in 25 sessions. Plans were compared according to dose-volume histogram analyses in terms of PTV homogeneity and conformity indices as well as organs at risk dose and volume parameters. Results: The HI and CI of PTV showed no difference between 3D-CRT and IMRT, V95 gave 9.8% coverage for 3D-CRT versus 99% for IMRT, V107 volumes were recorded 11% and 1.3%, respectively. Tangential beam IMRT increased volume of ipsilateral lung V5 average of 90%, ipsilateral V20 lung volume was 13%, 19% with IMRT and 3D-CRT respectively. Patients treated with IMRT, heart volume encompassed by 60% isodose (30 Gy) reduced by average 42% (4% versus 7% with 3D-CRT), mean heart dose by average 35% (495cGy versus 1400 cGy with 3D-CRT). In IMRT minimal heart dose average is 356 cGy versus 90cGy in 3D-CRT. Conclusions: IMRT reduces irradiated volumes of heart and ipsilateral lung in high-dose areas but increases irradiated volumes in low-dose areas in breast cancer patients treated on the left side.

• The Korean Journal of Physiology
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• 제1권1호
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• pp.77-82
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• 1967

The normal lung volumes were determined and subdivided under sitting position in 48 middle school girls, 49 high school girls and 44 house wives. All subjects were free of pulmonary and vascular diseases. The vital capacity was measured by Mckessons spirometer and the residual volume was determined by Rahn's three breathing method. 1. The lung volumes (BTPS) of middle school girls determined were: $RV\;0.59{\pm}0.11l\;FRC\;1.45{\pm}2.22l\;VC\;2.68{\pm}0.29l$ 2. The lung volumes (BTPS) of high school girls determined were: $RV\;0.83{\pm}0.19l\;FRC\;1.9{\pm}0.25l\;VC\;3.15{\pm}0.24l$ 3. The lung volumes (BTPS) of house wives determind were: $RV\;0.95{\pm}0.61{\ell}\;FRC\;2.1{\pm}0.25{\ell}\;VC\;3.06{\pm}0.29l$ 4. The calculated residual ratio $(RV/TLC{\times}100)$ were: $17.7{\pm}2.57%$ in middle school girls and $20.6{\pm}3.65%$ in high school girls and $24.0{\pm}2.31%$ in house wives 5. The functional residual ratio $(FRC/TLC{\times}100)$ were: $43.7{\pm}5.98%$ in middle school girls and $48.8{\pm}4.41%4 in high school girls and $52.6{\pm}5.38%$ in house wives. 6. The correlation coefficients between vital capacity and total lung capacity were r=0.96 in middle school girls and r=0.986 in high school girls and r=0.856 in house wives. 7. The regression equations were obtained follows: $TLC(l) =1.105{\times}VC+0.304$ (in middle school girls) $TLC(l) =1.551{\times}VC-0.902$ (in high school girls) $TLC(l) =0.999{\times}VC+0.954$ (in house wives)

• 한국CDE학회논문집
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• 제7권4호
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• pp.211-218
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• 2002

Swept volumes have been used in a wide variety of applications, and the literature contains much discussion of methods for computing the swept volumes in many situations. However, the commercially available CAD systems do not support the operations of generating the swept volumes enough to satisfy a variety of users' needs. In this paper, we present a new, simple and efficient algorithm for computing the swept volume of moving a polyhedron in 3-D region. The screw motion is used to describe the sweep motion of a polyhedron, because of its simplicity and computational advantages. The boundary of a swept volume is the result of combining the envelope surfaces and the partial boundaries at the initial and final position of a polyhedron. Some portions of these boundaries are inside the swept volume. We develop the algorithm to remove these interior portions. Then, to implement our algorithm, it is performed to integrate our program with the commercial CAD software, CATIA.

• Asian Pacific Journal of Cancer Prevention
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• 제17권11호
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• pp.4935-4937
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• 2016

Objective: To compare dosimetric parameters of 3 dimensional conformal radiotherapy (3 DCRT) and intensity modulated radiotherapy (IMRT) in terms of target coverage and doses to organs at risk (OAR) in the management of rectal carcinoma. Methods: In this prospective study, conducted between August 2014 and March 2016, all patients underwent CT simulation along with a bladder protocol and target contouring according to the Radiation Therapy Oncology Group (RTOG) guidelines. Two plans were made for each patient (3 DCRT and IMRT) for comparison of target coverage and OAR. Result: A total of 43 patients were recruited into this study. While there were no significant differences in mean Planning Target Volume (PTV) D95% and mean PTV D98% between 3 DCRT and IMRT, mean PTV D2% and mean PTV D50% were significantly higher in 3 DCRT plans. Compared to IMRT, 3 DCRT resulted in significantly higher volumes of hot spots, lower volumes of cold spots, and higher doses to the entire OAR. Conclusion: This study demonstrated that IMRT achieves superior normal tissue avoidance (bladder and bowel) compared to 3 DCRT, with comparable target dose coverage.