• The Korean Journal of Nuclear Medicine Technology
• /
• v.23 no.1
• /
• pp.54-58
• /
• 2019

Purpose At now, there are many kind of dedicated heart SPECT machine in clinical nuclear medicine. Among those, the fixed focusing type SPECT can make a good quality, quantity image because a detectors of this SPECT arranged forward a special ROI and didn't rotate around of body. So, in this paper, we will evaluate a spatial uniformity about resolution and sensitivity at a same plane of a fixed focusing type SPECT. Materials and Methods We used D-SPECT as a fixed focusing type SPECT and Cario MD as a rotated parallel type SPECT to comparing each other. We injected $^{99m}Tc(14.8MBq/1cc)$ to 10 capillary tube (diameter=1mm), and we set those line sources a tfield of view of each SPECT. And then we acquired SPECT date, we applied are construction by recommended methods. By using two tomography images, we calculated a full width of half maximum as a resolution and total counts as a sensitivity, and we compared a CV (coefficientofvariation) values between two images as a spatial uniformity. Results In case of D-SPECT, a CV of resolution and sensitivity are 7.45%, 12.34%. In case of Cario MD, an CV of resolution and sensitivity are 12.49%, 21.84% Conclusion As a results, CV of resolution and sensitivity of a fixed focusing type SPECT is 67.75%, 77.00% higher than ones of a rotated parallel type SPECT. It means that a fixed focusing type SPECT is more uniformed, because this new SPECT can reduce a motion blur artifact by rotating detector around body, also all of detector that made by semiconductor arrange forward a special FOV like heart.

• Journal of Biomedical Engineering Research
• /
• v.24 no.5
• /
• pp.401-410
• /
• 2003

This study investigates the biomechanical efficacies of various cement augmentation techniques with or without pressurization for varying degrees of osteoporotic femur. For this study, a biomechanical analysis using a finite element method (FEM) was undertaken to evaluate surgical procedures, Simulated models include the non-cemented(i.e., hip screw only, Type I), the cement-augmented(Type II), and the cemented augmented with pressurization(Type III) models. To simulate the fracture plane and other interfacial regions, 3-D contact elements were used with appropriate friction coefficients. Material properties of the cancellous bone were varied to accommodate varying degrees of osteoporosis(Singh indices, II∼V). For each model. the following items were analyzed to investigate the effect surgical procedures in relation to osteoporosis of varying degrees : (a) von Mises stress distribution within the femoral head in terms of volumetric percentages. (b) Peak von Mises stress(PVMS) within the femoral head and the surgical constructs. (c) Maximum von Mises strain(MVMS) within the femoral head, (d) micromotions at the fracture plane and at the interfacial region between surgical construct and surrounding bone. Type III showed the lowest PVMS and MVMS at the cancellous bone near the bone-construct interface regardless of bone densities. an indication of its least likelihood of construct loosening due to failure of the host bone. Particularly, its efficacy was more prominent when the bone density level was low. Micromotions at the interfacial surgical construct was lowest in Type III. followed by Type I and Type II. They were about 15-20% of other types. which suggested that pressurization was most effective in limiting the interfacial motion. Our results demonstrated the cement augmentation with hip screw could be more effective when used with pressurization technique for the treatment of intertrochanteric fractures. For patients with low bone density. its effectiveness can be more pronounced in limiting construct loosening and promoting bone union.

• Journal of the Korean Orthopaedic Association
• /
• v.56 no.3
• /
• pp.253-260
• /
• 2021

Purpose: The least constrained prosthesis is generally recommended in primary total knee arthroplasty (TKA). Nevertheless, a varus/valgus constrained (VVC) prosthesis should be implanted when a semi-constrained prosthesis is not good for adequate stability, especially in the coronal plane. In domestic situations, however, the VVC prosthesis could not always be prepared for every primary TKA case. Therefore, it is sometimes impractical to use a VVC prosthesis for unsual unstable situations. This study provides information for preparing VVC prostheses in the preoperative planning of primary TKA through an analysis of primary VVC TKA cases. Materials and Methods: This study reviewed 1,797 primary TKAs, performed between May 2003 and February 2016. The reasons for requiring VVC prosthesis and the preoperative conditions in 29 TKAs that underwent primary TKA with a VVC prosthesis were analyzed retrospectively. Results: In primary TKA, 29 cases (1.6%) in 27 patients (6 male and 21 female) used VVC prosthesis. Two patients underwent a VVC prosthesis on both knees. The mean age of the patients was 63.4 years old (34-79 years). The mean flexion contracture was 16.2° (-20°-90°), and the mean angle of great flexion was 111.7° (35°-145°). The situations requiring a VVC prosthesis were severe valgus deformity in 10 knees, knee stiffness requiring extensive soft tissue release in 10 knees, previously injured collateral ligaments in five knees, and distal femoral bone defect due to avascular necrosis in four knees. The mean tibiofemoral angle was 25.7° (21°-43°) in 10 cases with a valgus deformity. The mean flexion contracture was 37.5° (20°-90°), and the mean range of motion was 48.5° (10°-70°) in 10 cases with knee stiffness. Conclusion: The preparation of VVC prosthesis is recommended, even for primary TKA in cases of severe valgus deformity (tibiofemoral angle>20°), stiff knee (the range of motion: less than 70° with more than 20° flexion contracture), and the cases with a previous collateral ligament injury. This information will help in the preparation of adequate TKA prostheses for unusual unstable situations.

• The Journal of Korean Academy of Prosthodontics
• /
• v.54 no.3
• /
• pp.226-233
• /
• 2016

Purpose: The purpose of this study was to evaluate the adaptation of lithium disilicate crowns fabricated by CAD-CAM (computer aided design-computer aided manufacturing) and heat-press technique to compare two different measurement methods in assessing fit of the ceramic crowns: micro CT and cross-section technique. Materials and methods: A prepared typodont mandibular molar for ceramic crown was duplicated and ten dies were produced by milling the PMMA (polymethylmethacrylate) resin. Ten vinyl polysiloxane impressions were made and stone casts were produced. Five dies were used for IPS e.max Press crowns with heat-press technique. The other five dies were used for IPS e.max CAD crowns with CAD-CAM technique. Ten lithium disilicate crowns were cemented on the resin dies using zinc phosphate cement with finger pressure. The marginal and internal fits in central buccolingual plane were evaluated using a micro CT. Then the specimens were embedded and cross-sectioned and the marginal and internal fits were measured using scanning electronic microscope. The two measurement methods and two manufacturing methods were compared using Mann-Whitney U test (SPSS 22.0). Results: The marginal and internal fit values using micro CT and cross-section technique were similar, showing no significant differences. There were no significant differences in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique. Conclusion: Both micro CT and cross-section technique were acceptable methods in the evaluation of marginal and internal fit of lithium disilicate crown. There was no difference in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique except occlusal fit.

• Progress in Medical Physics
• /
• v.18 no.3
• /
• pp.118-125
• /
• 2007

In this study we estimated a geometric correlation among digitally reconstructed radiographic image (DRRI), kV x-ray image (kVXI) from the On-Board Imager (OBI) and electric portal image (EPI). To verify geometric correspondence of DRRI, kVXI and EPI, specially designed phantom with indexed 6 ball bearings (BBs) were employed. After accurate setup of the phantom on a treatment couch using orthogonal EPIs, we acquired set of orthogonal kVXIs and EPIs then compared the absolute positions of the center of the BBs calculated at each phantom plane for kVXI and EPI respectively. We also checked matching result for obliquely incident beam (gantry angle of $315^{\circ}$) after 2D-2D matching provided by OBI application. A reference EPI obtained after initial setup of the phantom was compared with 10 series of EPIs acquired after each 2D-2D matching. Imaginary setup errors were generated from -5 mm to 5 mm at each couch motion direction. Calculated positions of all center positions of the BBs at three different images were agreed with the actual points within a millimeter and each other. Calculated center positions of the BBs from the reference and obtained EPIs after 2D-2D matching agreed within a millimeter. We could tentatively conclude that the OBI system was mechanically quite reliable for image guided radiation therapy (IGRT) purpose.

• The Journal of Korean Society for Radiation Therapy
• /
• v.27 no.1
• /
• pp.73-78
• /
• 2015

Purpose : Under the assumption of change to the amplitude based sorting, the study will use four dimensional computed tomography imaging (4DCT) arrayed using the phase based sorting to analyze the respiratory phase difference. Materials and Methods : The study analyzed the 4DCT (4-dimensional computed tomography) images of 10 liver cancer patients that were treated with respiratory gated radiotherapy from 2015 February to March. Using RPM respiratory gating (RPM 1.7.5, Varian, USA) equipment, imaging according to respiratory cycle of phase based sorting was acquired and using a treatment planning system (Pinnacle 9.2, Philips, USA) the acquired imaging according to respiratory cycle was used to measure the abdominal movement value by respiratory cycle. The measuring point was the point where the center point of the Marker Block and the body surface met in the 50% phase image and here the coordinate values Lateral, Vertical, Longitudinal (X, Y, Z) were set as reference points, and on the X, Z plane identical to the reference point, using the identical method the Y axis coordinate value of each 0%, 30%, 40%, 50%, 60%, 80% phase images were acquired to quantitatively measure the variation of distance to the Y axis. The abdominal movement value according to respiration was applied to the theoretical model that the value decreases linearly from maximum inhalation to maximum exhalation to divide the variation of my value to predict as amplitude value by respiratory cycle and conversely the variation in amplitude was recalculated with the phase variation deviation value to analyze. Results : The deviation value between expected value and actual location was the largest in the 30% phase with 0.24 cm, and standard deviation was also the largest in 30% phase with 0.13 cm. The effective value of the deviation value derived from the average of the deviation squared value of each patient appeared as minimum 0.7 cm, maximum 0.18 cm, average 0.12 cm, and standard deviation 0.4 cm. Also by dividing the actual movement distance value with the peak expiration value then converting it into %Phase, the deviation value with actual phase 16.5% in 30% phase, 10.0% and 40% phase, 10.0% and 60% phase, 15.4% and 80% phase, and overall average about 13%, and arraying based on amplitude, phase shift occurred and further it was from peak expiration the chance of deviation occurrence was increasingly measured. Conclusion : Based on the results of the study there were differences between value acquired based on theoretical model and actual value. Therefore in respiratory gated radiotherapy using external surrogates, there needs to be establishment of respiration gated radiation system that avoids the combination of two Sorting methods considering that there will be occurrence of treatment and corresponding clinical differences due to the phase difference that occur due to the Amplitude based Phase Sorting.

• Korean Journal of Digital Imaging in Medicine
• /
• v.16 no.1
• /
• pp.13-19
• /
• 2014

Purpose: FLAIR image is beneficial for the diagnosis of various bran diseases including ischemic CVS, brain tumors and infections. However the border between the legion of brain metastasis and surrounding edema may not be clear. Therefore, this study aims to investigate the practical benefits of delayed imaging by comparing the image from a patient with brain metastasis before a contrast enhancement and the image 10 minutes after a contrast enhancement. Materials and methods: Of the 92 people who underwent MRI brain metastases in suspected patients 13 people in three patients there is no video to target the 37 people confirmed cases, and motion artifacts brain metastases in our hospital June-December 2013, 18 people measurement position except for the three incorrect patient (male: 11 people, female: 7 people, average age: 60 years) in the target, test equipment, 3.0T MR System (ACHIEVA Release, Philips, I was 8ChannelSENSE Head Coil use Best, and the Netherlands). TR 11000 ms, TE 125 ms, TI2800 ms, Slice Thickness 5 mm, gap 5 mm, is a Slice number 21, the parameters of the 3D FFE, T2 FLAIR variable that was used to test, TR 8.1 ms, TE 3.7 ms, Slice number 240 I set to. The experiment was conducted by acquiring the FLAIR prior to contrast enhancement (heretofore referred to as Pre FLAIR), and acquiring the 3D FFE CE five minutes after the contrast enhancement, and recomposing the images in an axial plane of S/T 3mm, G 0mm (heretofore referred to as MPR TRA CE). Using the FLAIR 10 minutes after the contrast enhancement (heretofore referred to as Post FLAIR) and Pi-View, a retrospective study was conducted. Using MRIcro on the image of a patient confirmed for his diagnosis, the images before and after the contrast media, as well as the CNR and SNR of the MPR TRA CE images of the lesion and the site absent of lesion were compared and analyzed using a one-way analysis of variance. Results: CNR for Pre FLAIR and Post FLAIR were 34.35 and 60.13, respectively, with MPR TRA CE at 23.77 showing no significant difference (p<0.050). Post-experiment analysis shows a difference between Pre FLAIR and Post FLAIR in terms of CNR (p<0.050), but no difference in CNR between Post FLAIR and MPR TRA CE (p>0.050), indicating that the contrast media had an effect only on Pre FLAIR and Post FLAIR. The SNR for the normal site Pre FLAIR was 106.43, and for the lesion site 140.79. Post FLAIR for the normal site was 107.79, and for the lesion site 167.91. MPR TRA CE for the normal site was 140.23 and for the lesion site 183.19, showing significant difference (p<0.050), and post-experiment analysis shows that there was a difference in SNR only on the lesion sites for Pre FLAIR and Post FLAIR (p<0.050). There was no difference in SNR between the normal site and lesion site for Post FLAIR and MPR TRA CE, indicating no effect from the contrast media (p>0.050). Conclusions: This experiment shows that Post FLAIR has a higher contrast than Pre FLAIR, and a higher SNR for lesions, It was not not statistically significant and MPR TRA CE but CNR came out high. Inspection of post-contrast which is used in a high magnetic field is frequently used images of 3D T1 but, since the signal of the contrast medium and the blood flow is included, this method can be diagnostic accuracy is reduced, it is believed that when used in combination with Post FLAIR, and that can provide video information added to the diagnosis of brain metastases.

• Journal of Naturopathy
• /
• v.9 no.1
• /
• pp.22-26
• /
• 2020

Purposes: The purposes of this study were to investigate the relationship between the standing position of the subject and the normal standing position(NSP) and the straight standing position(SSP) and to investigate the possibility of different body shape test results depending on the status of the image inspection apparatus. Methods: The images of the NSP and SSP were compared with each other by body line BLS system. Results: At the time of examination, the position of the camera was captured at a position 2.3 m vertically from the posterior position 45 cm behind the subject. This is a privacy protection method for covering the breast of the subject. Results: The physiological characteristics of the anatomical position of the body align image test are the living body. NSP and SSP tests showed different shapes of the pelvis AS(antero-supero) and pelvis rotation in the transverse plane. Shoulder and arm displacement was observed in the trunk extension image capture. Conclusions: In the body alignment test, the pelvis position test images of NSP and SSP are evaluated differently for pelvis rotation, AS, and PS. At the extension position of the trunk, a test of the maximal extension range showed that the left and right shortening of the shoulder anterior muscles could be observed. Inducing and testing the trunk extension is also useful.

• Journal of the Korean Orthopaedic Association
• /
• v.56 no.1
• /
• pp.51-60
• /
• 2021

Purpose: Radiocarpal dislocation (RCD), which is caused by high-energy trauma, often involves radial styloid fractures and short radiolunate ligament (SRLL) injuries. Although SRLL injuries may occur as a simple rupture at the attachment site of radius, it may occur with a relatively large avulsed-fragment in the volar rim of the lunate facet of the radius. This study aimed to differentiate the injury type of SRLL and assess the differences in the treatment results depending on the treatment methods that have been applied in RCD with radial styloid fractures. Materials and Methods: Eighteen patients managed surgically with RCD were enrolled in this study. The patients were classified as Group 1 and Group 2 by using the Dumontier method. In this study, Group 2 was subdivided into 2A (purely ligamentous or small avulsion fracture of the volar rim of lunate facet) and 2B (large avulsed-fragment enough to internal fixation) according to the injury type of SRLL. Groups 2A and 2B were treated with direct repair and screw fixation, respectively. Pain, range of motion of the wrist joint, grip strength, and complications on final radiographs were examined. The outcomes were evaluated using patient-rated wrist evaluation (PRWE), and modified Mayo wrist score (MMWS). Results: All patients were Group 2 (six and twelve patients in 2A and 2B, respectively). The mean flexion to extension arch recovered 79%,and the mean grip strength was 72.9% of the uninjured side. Group 2A showed better recovery in extension, flexion and pronation than Group 2B, but there was no difference in radial deviation, ulnar deviation, supination, grip strength and pain. No differences in the PRWE and MMWS were observed between two groups. Complications included traumatic arthritis in seven patients and residual instability in five patients. Conclusion: When the SRLL was injured, the involvement of a large avulsion fracture on the anterior plane of the radiolunate did not affect the test results. On the other hand, it should be observed cautiously because avulsion fractures tend to disturb the joint's reduction through rotation or displacement. In addition, anatomical reduction and sturdy internal fixation are important for restoring the function of the SRLL.