• Title/Summary/Keyword: Axial scan

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Measurement of Patient Dose from Computed Tomography Using Physical Anthropomorphic Phantom (물리적 팬텀을 이용한 CT 촬영 환자의 피폭 선량 측정 및 평가)

  • Jang, Ki-Won;Lee, Choon-Sik;Kwon, Jung-Wan;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.30 no.3
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    • pp.113-119
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    • 2005
  • The computed tomogrpahy(CT) provides a high quality in images of human body but contributes to the relatively high patient dose. The frequency of CT examination is increasing and, therefore, the concerns about the patient dose are also increasing. In this study the experimental determination of patient dose was performed by using a physical anthropomorphic phantom and thermoluminescent dosimeter(TLD). The measurements were done for the both axial and spiral scan mode. As a result the effective doses for each scan mode were 17.78mSv and 10.01 mSv respectively and the fact that the degree of the reduction in the patient dose depends on the pitch scan parameter was confirmed. The measurement methods suggested in this study can be applied for the reassessment of the patient dose when the technique in CT equipment is developed or the protocol for CT scanning is changed.

Analysis of Image Distortion on Magnetic Resonance Diffusion Weighted Imaging

  • Cho, Ah Rang;Lee, Hae Kag;Yoo, Heung Joon;Park, Cheol-Soo
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.381-386
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    • 2015
  • The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

Bone Marrow Scintigraphy with Antigranulocyte Antibody in Multiple Myeloma: Comparison with Simple Radiography and Bone Scintigraphy (항과립구 항체 골수스캔을 이용한 다발성 골수종 병변의 평가: 단순골X-선점사 및 골스캔과의 비교)

  • Kim, Dong-Hwan;Lee, Jae-Tae;Baek, Jin-Ho;Jung, Jin-Tae;Hyun, Dong-Woo;Chun, Kyung-Ah;Lee, Young-Hak;Sohn, Sang-Kyun;Song, Hong-Seok;Lee, Kyu-Bo
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.4
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    • pp.354-364
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    • 1998
  • Purpose: Simple X-ray study and bone scan have limitations for early diagnosis of bone or bone marrow lesions in multiple myeloma. The purpose of this study was to evaluate the diagnostic usefulness of bone marrow immunoscintigraphy using anti-granulocyte monoclonal antibody for the evaluation of bone involvement in multiple myeloma. Materials and Methods: In 22 patients (Male: 15, Female: 7) with multiple myeloma, we performed whole-body immunoscintigraphy using $^{99m}Tc$-labelled antigranulocyte antibody (BW 250/183, Scintimum $Granulozyt^{(R)}$ CIS, France) and compared the findings with those of simple bone radiography and $^{99m}Tc$-MDP bone scan. Abnormal findings in bone marrow scintigraphy were, considered to be present in case of expansion of peripheral bone marrow or focal photon defect in axial bones. Results: Marrow expansion was noted in 15 of 22 patients (68%). Focal photon defects were found in 18 patients (82%). While one (33%) of 3 patients with Stage II disease showed focal defects in bone marrow scan, abnormal focal defects were observed in 17 of 19 (90%) patients with Stage III. Among 124 focal abnormal sites which were observed in bone marrow scan, bone scan or simple bone radiography, bone marrow scan detected 92 sites (74%), whereas 82 sites (66%) were observed in simple bone radiography(58 sites, 47%) or bone scan(40 sites, 32%). Fifty-one (41%) out of 124 bone lesions were detected by bone marrow scan only, and located mostly in thoracolumbar spine. Conclusion: Bone marrow scan using $^{99m}Tc$-labelled antigranulocyte antibody seems to be a more sensitive procedure for the detection of pathologic bone lesions than simple bone X-ray or bone scan in patients with multiple myeloma.

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Evaluation of Dimensions of Kambin's Triangle to Calculate Maximum Permissible Cannula Diameter for Percutaneous Endoscopic Lumbar Discectomy : A 3-Dimensional Magnetic Resonance Imaging Based Study

  • Pairaiturkar, Pradyumna Purushottam;Sudame, Onkar Shekhar;Pophale, Chetan Shashikant
    • Journal of Korean Neurosurgical Society
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    • v.62 no.4
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    • pp.414-421
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    • 2019
  • Objective : To evaluate 3-dimensional magnetic resonance imaging (MRI) of Kambin's safe zone to calculate maximum cannula diameter permissible for safe percutaneous endoscopic lumbar discectomy. Methods : Fifty 3D MRIs of 19 males and 31 females (mean, 47 years) were analysed. Oblique, axial and sagittal views were used for image analysis. Three authors calculated the inscribed circle (cannula diameter) individually, within the neural (original) and bony Kambin's triangle in oblique views, disc heights on sagittal views and root to facet distances at upper and lower end plate levels on axial views and their averages were taken. Results : The mean root to facet distances at upper end plate level measured on axial sections increased from $3.42{\pm}3.01mm$ at L12 level to $4.57{\pm}2.49mm$ at L5S1 level. The mean root to facet distances at lower end plate level measured on axial sections also increased from $6.07{\pm}1.13mm$ at L12 level to $12.9{\pm}2.83mm$ at L5S1 level. Mean maximum cannula diameter permissible through the neural Kambin's triangle increased from $5.67{\pm}1.38mm$ at L12 level to $9.7{\pm}3.82mm$ at L5S1 level. The mean maximum cannula diameter permissible through the bony Kambin's triangle also increased from $4.03{\pm}1.08mm$ at L12 level to $6.11{\pm}1mm$ at L5S1 level. Only 2% of the 427 bony Kambin's triangles could accommodate a cannula diameter of 8mm. The base of the bony Kambin's triangle taken in oblique view (3D MRI) was significantly higher than the root to facet distance at lower end plate level taken in axial view. Conclusion : The largest mean diameter of endoscopic cannula passable through "bony" Kambin's triangle was distinctively smaller than the largest mean diameter of endoscopic cannula passable through "neural" Kambin's triangle at all levels. Although proximity of exiting root to the facet joint is always taken into consideration before PELD procedure, our 3D MRI based anatomical study is the first to provide actual maximum cannula dimensions permissible in this region.

Composite Neuroendocrine Carcinoma with Adenocarcinoma of the Stomach Misdiagnosed as a Giant Submucosal Tumor

  • Kim, Tae-Yoon;Chae, Hyun-Dong
    • Journal of Gastric Cancer
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    • v.11 no.2
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    • pp.126-130
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    • 2011
  • A composite glandular/exocrine-endocrine carcinoma of the gastrointestinal tract is characterized by the co-existence of two adjacent, but histologically-distinct tumors in an organ. Composite glandular/exocrine-endocrine carcinomas are a special type of tumor comprised of common adenocarcinomas and neuroendocrine components that account for at least one-third of the entire tumor area. Composite tumors have been reported in a range of organs, but are relatively rare in the stomach. We report a case of a composite neuroendocrine carcinoma with an adenocarcinoma of the stomach (mixed exocrine-endocrine carcinoma), which was misdiagnosed as a giant submucosal tumor preoperatively based on esophagogastroduodenoscopy and a contrast-enhanced axial computed tomographic scan.

Complex Conjugate Resolved Retinal Imaging by One-micrometer Spectral Domain Optical Coherence Tomography Using an Electro-optical Phase Modulator

  • Fabritius, Tapio E.J.;Makita, Shuichi;Yamanari, Masahiro;Myllyla, Risto A.;Yasuno, Yoshiaki
    • Journal of the Optical Society of Korea
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    • v.15 no.2
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    • pp.111-117
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    • 2011
  • Full-range spectral domain optical coherence tomography (SD-OCT) with a 1-${\mu}m$ band light source is shown here. The phase of the reference beam is continuously stepped while the probing beam scans the sample laterally (B-scan). The two dimensional spectral interferogram obtained is processed by a Fourier transform method to obtain a complex spectrum leading to a full-range OCT image. A detailed mathematical explanation of the complex conjugate resolving method utilized is provided. The system's measurement speed was 7.96 kHz, the measured axial resolution was $9.6{\mu}m$ in air and the maximum sensitivity 99.4 dB. To demonstrate the effect of mirror image elimination, In vivo human eye pathology was measured.

Accuracy in target localization in stereotactic radiosurgery using diagnostic machines (정위적 방사선수술시 진단장비를 이용한 종양위치결정의 정확도 평가)

  • 최동락
    • Progress in Medical Physics
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    • v.7 no.1
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    • pp.3-7
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    • 1996
  • The accuracy in target localization of CT, MR, and digital angiography were investigated for stereotactic radiosurgery. The images using CT and MR were obtained out of geometrical phantom which was designed to produce exact coordinates of several points within a 0.lmm error range. The slice interval was 3mm and FOV was 35cm for CT and 28cm for MR. These images were transferred to treatment planning computer using TCP/IP in forms of GE format. Measured 3-D coordinates of these images from planning computer were compared to known values by geometrical phantom. Anterior-posterior and lateral films were taken by digital angiography for measurement of spatial accuracy. Target localization errors were 1.2${\pm}$0.5mm with CT images, 1.7${\pm}$0.4mm with MR-coronal images, and 2.1${\pm}$0.7mm with MR-sagittal images. But, in case of MR-axial images, the target localization error was 4.7${\pm}$0.9mm. Finally, the target localization error of digital angiography was 0.9${\pm}$0.4mm. The accuracy of diagnostic machines such as CT, MR, and angiography depended on their resolutions and distortions. The target localization error mainly depended on the resolution due to slice interval with CT and the image distortion as well as the resolution with MR However, in case of digital angiography, the target localization error was closely related to the distortion of fiducial markers. The results of our study should be considered when PTV (Planning Target Volume) was determined.

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Image Evaluation Analysis of CT Examination for Pedicle Screw Insertion (척추경 나사못 삽입술 CT검사의 영상평가 분석)

  • Hwang, Hyung-Suk;Im, In-Chul
    • Journal of the Korean Society of Radiology
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    • v.16 no.2
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    • pp.131-139
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    • 2022
  • The purpose of this study was to insert a pedicle screw into a pig thoracic vertebrae, a general CT scan(Non MAR), and a thoracic axial image obtained with the Metallic Artifact Reduction for Orthopedic Implants (O-MAR) to reduce artifacts. The image obtained by reconstructing the algorithm (Standard, Soft, Bone, Detail) was used using the image J program. Signal to noise ratio(SNR) and contrast to noise ratio(CNR) were compared and analyzed by obtaining measured values based on the given equation. And this study was to investigate tube voltage and algorithm suitable for CT scan for thoracic pedicle screw insertion. As a result, when non-MAR was used, the soft algorithm showed the highest SNR and CNR at 80, 100, 120, and 140 kVp, On the other hand, when MAR was used, the standard algorithm showed the highest at 80 kVp, and the standard and soft algorithms showed similar values at 100 kVp. At 120 kVp, the Soft and Standard algorithms showed similar values, and at 140 kVp, the Soft algorithm showed the highest SNR and CNR. Therefore, when comparing Non-MAR and MAR, even if MAR was used, SNR and CNR did not increase in all algorithms according to the change in tube voltage. In conclusion, it is judged that it is advantageous to use the Soft algorithm at 80, 100, 120, and 140 kVp in Non MAR, the Standard algorithm at 80 and 100 kVp in MAR, and the Soft algorithm at 120 and 140 kVp. This study is expected to serve as an opportunity to further improve the quality of images by using selective tube voltage and algorithms as basic data to help evaluate images of pedicle screw CT scans in the future.

Altered Biodistribution of Gallium-67 in a Patient with Multiple Factors Influencing Iron-transport Protein Saturation (철운반단백질 포화정도에 따른 Gallium-67 체내분포의 변화: 증례보고)

  • Choi, Joon Young;Kim, Sang Eun;Lee, Kyung Han;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.1
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    • pp.114-119
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    • 1998
  • We present a case of a young female patient with fulminant hepatitis who showed an altered biodistribution of Ga-67, after being scanned twice at 10 month intervals. On initial scan, uplake of Ga-67 was increased in the liver, kidneys, and skeletons. Increased hepatic Ga-67 uptake may be explained by increased transferrin unbound Ga-67 that was taken up by the inflamed liver. The saturation of iron-binding proteins due to multiple transfusions may lead to increased renal and skeletal Ga-67 uptake. On follow-up scan hepatic Ga-67 uptake was markedly increased. Also increased Ga-67 uptake in the axial skeleton and normalized renal uptake were shown. The findings were consistent with iron deficiency anemia. This case demonstrates altered Ga-67 biodistribution associated with multiple transfusions, fulminant hepatitis, and iron deficiency anemia.

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Changes on Magnetic resonance imaging in lumbar disc herniations treated with oriental medicine (한의학적 치료법으로 호전된 요추 추간판 탈출증 환자의 영상의학적 변화)

  • Kim, Wu-Young;Han, Sang-Yup;Kim, Ki-Yuk;Kong, Duck-Hyun;Lee, Hyun-Jong;Kim, Chang-Youn;Nam, Hang-Woo
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.4 no.1
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    • pp.31-41
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    • 2009
  • Objectives: The aim of this study was to evaluate the evolution of lumbar disc herniation in patients treated with oriental medicine. Methods: 14patients(15 cases) with lumbar disc herniation proved at MRI(Magnetic resonance imaging) underwent a follow-up MRI study. Follow-up MRI was performed $4{\sim}14$months(mean 7 months) after initial MRI. Results & Conclusions: 1. 13 cases(87%) had reduction of disc herniation. 1 showed no change in amount of disc herniation. 1 had an increase in disc herniation. 2. Comparison initial MRI with follow-up MRI showed that 2 of the herniations decreased between 0% and 25%, 3 decreased between 25% and 50%, 5 decreased between 50% and 75%, 3 decreased between 75% and 100%. The size of the herniation decreased on average by 49% in 14patients(15 cases). 3. On axial images, the proportion of the cross-sectional area of the spinal canal occupied by the herniated disc was 54.41% on the average on the initial scan, 29.65% on the follow-up scan.

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