• Journal of radiological science and technology
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• v.36 no.2
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• pp.131-139
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• 2013

The aim of this study was to evaluate the variation which based on Celiac axis and SMA using by CT volume rendering images. 613 patients underwent abdominal CTA, there were 552 patients (99.05%, TypeI, II) with normal anatomical form and 61 (9.95%, Type III~XII) with variation. TypeI was 339(55.31%), Type II was 213 (34.74%), Type III was 18 (2.93%), Type IV was 12 patients (1.95%), Type V was 11 patient (1.79%), Type VI was 9 patients (1.46%), Type VII was 6 patients (0.97%), Type VIII was 1 patient (0.16%), Type IX was 1 patient (0.16%), Type X was 1 patient (0.16%), Type XI was 1 patient (0.16%), and Type XII was 1 patient (0.16%) into totally new types of variation. In conclusion, we could found 9 new types of variation by classifying based on celiac axis and superior mesenteric artery. These results were considered to be an important opportunity for a new vessel map.

• Journal of Korean Neurosurgical Society
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• v.30 no.7
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• pp.907-915
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• 2001

Objective : Percutaneous vertebroplasty is often complicated by the presence of multiple fractures or non-localizing pain in the patients with osteoporotic vertebral fractures. The purpose of this study is to estimate the value of preoperative radiologic studies in the localization of symptomatic vertebrae and to determine the factors which can influence on the clinical results. Materials and Methods : We retrospectively reviewed the clinical and radiologic data of 57 vertebrae in 30 patients underwent percutaneous vertebroplasty for osteoporotic vertebral compression fractures. Inclusion criteria was severe pain(McGill-Melzack score 3, 4 or 5) associated with the acute vertebral fractures and absence of spinal nerve root or cord compression sign. Acute symptomatic vertebral fracture was determined by the presence of signal change on MR images or increased uptake on whole body bone scan. Results : Pain improvement was obtained immediately in all patients and favorable result was sustained in 26 patients(86.7%) during the mean follow-up duration of 4.7 months(5 complete pain relief, 21 marked pain relief). Those who underwent vertebroplasty for all acute symptomatic vertebrae had significantly better clinical result than those who did not. Further vertebral collapse and eventual bursting fracture occurred in 1 vertebra which showed intradiskal leakage of bone cement and disruption of cortical endplate on postoperative CT scan. Conclusion : Preoperative MR imaging and whole body bone scan are very useful in determining the symptomatic vertebrae, especially in the patients with multiple osteoporotic vertebral fractures. To obtain favorable clinical result, the careful radiologic evaluation as well as clinical assessment is required. Control of PMMA volume seems to be the most critical point for avoiding complications.

• KIPS Transactions on Software and Data Engineering
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• v.1 no.2
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• pp.109-114
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• 2012

Honeycombs are dense structures that small cysts, which generally have about 2~10 mm in diameter, are surrounded by the wall of fibrosis. When honeycomb is found in the patients, the incidence of acute exacerbation is generally very high. Thus, the observation and quantitative measurement of honeycomb are considered as a significant marker for clinical diagnosis. In this point of view, we propose an automatic segmentation method using morphological image processing and assessment of the degree of clustering techniques. Firstly, image noises were removed by the Gaussian filtering and then a morphological dilation method was applied to segment lung regions. Secondly, honeycomb cyst candidates were detected through the 8-neighborhood pixel exploration, and then non-cyst regions were removed using the region growing method and wall pattern testing. Lastly, final honeycomb regions were segmented through the extraction of dense regions which are consisted of two or more cysts using cluster analysis. The proposed method applied to 80 High resolution computed tomography (HRCT) images and achieved a sensitivity of 89.4% and PPV (Positive Predictive Value) of 72.2%.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.55-62
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• 2021

Purpose: This study aims to contribute to the reduction of complications of breast cancer radiation therapy by analyzing skin dose differences due to Set-up error. Materials and Method: Pseudo breast was produced using a 3D printer, applied to the phantom, and images were acquired through CT. Treatment plan was carried out that the PTV, which contains 95% of the prescription dose, could be more than 95% of the volume, so that Dmax did not exceed 107% of the prescription dose. The Set-up error was evaluated by applying ±1mm/±3mm/±5mm to the X-axis, Y-axis, and Z-axis. Results: The dose-variation in skin due to Set-up error was approximately 106% to 123% compared to prescription dose, and the highest dose in skin was 49.24 Gy at 5mm Set-up error in the lateral direction of the X-axis. More than 107% of the prescription dose was the widest at 6.87 cc in skin lateral. Conclusions: If a Set-up error occurs during left breast cancer VMAT, a great difference in skin dose was shown in the lateral direction of the X-axis. If more effort is made to align the X-axis of the breast treated during CBCT registration, the dose-variation of skin will be reduced.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.7
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• pp.233-240
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• 2022

Most of the recent AI researches has focused on developing AI models. However, recently, artificial intelligence research has gradually changed from model-centric to data-centric, and the importance of learning data is getting a lot of attention based on this trend. However, it takes a lot of time and effort because the preparation of learning data takes up a significant part of the entire process, and the generation of labeling data also differs depending on the purpose of development. Therefore, it is need to develop a tool with various labeling functions to solve the existing unmetneeds. In this paper, we describe a labeling system for creating precise and fast labeling data of medical images. To implement this, a semi-automatic method using Back Projection, Grabcut techniques and an automatic method predicted through a machine learning model were implemented. We not only showed the advantage of running time for the generation of labeling data of the proposed system, but also showed superiority through comparative evaluation of accuracy. In addition, by analyzing the image data set of about 1,000 patients, meaningful diagnostic indexes were presented for men and women in the diagnosis of sarcopenia.

• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1286-1297
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• 2022

Purpose To assess the usefulness of various metal artifact reduction (MAR) methods in patients with hip prostheses. Materials and Methods This retrospective study included 47 consecutive patients who underwent hip arthroplasty and dual-energy CT. Conventional polyenergetic image (CI), orthopedic-MAR (OMAR), and virtual monoenergetic image (VMI, 50-200 keV) were tested for MAR. Quantitative analysis was performed in seven regions around the prostheses. Qualitative assessments included evaluation of the degree of artifacts and the presence of secondary artifacts. Results The lowest amount of image noise was observed in the O-MAR, followed by the VMI. O-MAR also showed the lowest artifact index, followed by high-keV VMI in the range of 120-200 keV (soft tissue) or 200 keV (bone). O-MAR had the highest contrast-to-noise ratio (CNR) in regions with severe hypodense artifacts, while VMI had the highest CNR in other regions, including the periprosthetic bone. On assessment of the CI of pelvic soft tissues, VMI showed a higher structural similarity than O-MAR. Upon qualitative analysis, metal artifacts were significantly reduced in O-MAR, followed by that in VMI, while secondary artifacts were the most frequently found in the O-MAR (p < 0.001). Conclusion O-MAR is the best technique for severe MAR, but it can generate secondary artifacts. VMI at high keV can be advantageous for evaluating periprosthetic bone.

• Korean Journal of Radiology
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• v.25 no.2
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• pp.179-188
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• 2024

Objective: ¹⁷⁷Lutetium [Lu] Ludotadipep is a novel prostate-specific membrane antigen targeting therapeutic agent with an albumin motif added to increase uptake in the tumors. We assessed the biodistribution and dosimetry of [¹⁷⁷Lu]Ludotadipep in patients with metastatic castration-resistant prostate cancer (mCRPC). Materials and Methods: Data from 25 patients (median age, 73 years; range, 60-90) with mCRPC from a phase I study with activity escalation design of single administration of [¹⁷⁷Lu]Ludotadipep (1.85, 2.78, 3.70, 4.63, and 5.55 GBq) were assessed. Activity in the salivary glands, lungs, liver, kidneys, and spleen was estimated from whole-body scan and abdominal SPECT/CT images acquired at 2, 24, 48, 72, and 168 h after administration of [¹⁷⁷Lu]Ludotadipep. Red marrow activity was calculated from blood samples obtained at 3, 10, 30, 60, and 180 min, and at 24, 48, and 72 h after administration. Organand tumor-based absorbed dose calculations were performed using IDAC-Dose 2.1. Results: Absorbed dose coefficient (mean ± standard deviation) of normal organs was 1.17 ± 0.81 Gy/GBq for salivary glands, 0.05 ± 0.02 Gy/GBq for lungs, 0.14 ± 0.06 Gy/GBq for liver, 0.77 ± 0.28 Gy/GBq for kidneys, 0.12 ± 0.06 Gy/GBq for spleen, and 0.07 ± 0.02 Gy/GBq for red marrow. The absorbed dose coefficient of the tumors was 10.43 ± 7.77 Gy/GBq. Conclusion: [¹⁷⁷Lu]Ludotadipep is expected to be safe at the dose of 3.7 GBq times 6 cycles planned for a phase II clinical trial with kidneys and bone marrow being the critical organs, and shows a high tumor absorbed dose.

• Korean Journal of Radiology
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• v.23 no.11
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• pp.1055-1066
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• 2022

Objective: The clinical relevance of myosteatosis has not been well evaluated in patients with pancreatic ductal adenocarcinoma (PDAC), although sarcopenia has been extensively researched. Therefore, we evaluated the prognostic value of muscle quality, including myosteatosis, in patients with resectable PDAC treated surgically. Materials and Methods: We retrospectively evaluated 347 patients with resectable PDAC who underwent curative surgery (mean age ± standard deviation, 63.6 ± 9.6 years; 202 male). Automatic muscle segmentation was performed on preoperative computed tomography (CT) images using an artificial intelligence program. A single axial image of the portal phase at the inferior endplate level of the L3 vertebra was used for analysis in each patient. Sarcopenia was evaluated using the skeletal muscle index, calculated as the skeletal muscle area (SMA) divided by the height squared. The mean SMA attenuation was used to evaluate myosteatosis. Diagnostic cutoff values for sarcopenia and myosteatosis were devised using the Contal and O'Quigley methods, and patients were classified according to normal (nMT), sarcopenic (sMT), myosteatotic (mMT), or combined (cMT) muscle quality types. Multivariable Cox regression analyses were conducted to assess the effects of muscle type on the overall survival (OS) and recurrence-free survival (RFS) after surgery. Results: Eighty-four (24.2%), 73 (21.0%), 75 (21.6%), and 115 (33.1%) patients were classified as having nMT, sMT, mMT, and cMT, respectively. Compared to nMT, mMT and cMT were significantly associated with poorer OS, with hazard ratios (HRs) of 1.49 (95% confidence interval, 1.00-2.22) and 1.68 (1.16-2.43), respectively, while sMT was not (HR of 1.40 [0.94-2.10]). Only mMT was significantly associated with poorer RFS, with an HR of 1.59 (1.07-2.35), while sMT and cMT were not. Conclusion: Myosteatosis was associated with poor OS and RFS in patients with resectable PDAC who underwent curative surgery.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.16-22
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• 2006

Purpose: Malignant Mixed Mullerian Tumor (MMMT) of the uterine corpus is one of the very uncommon and the most lethal tumors in the uterus. The aim of this study was to evaluate the role of FDG PET in detecting distant metastasis and residual and/or recurrent disease. Methods: Ten patients who underwent FDG PET for detecting distant metastasis and recurrence were included. focal FDG accumulation was regarded as abnormal. We also reviewed serum CA 125 levels, anatomical images, and histopathoiogical examination. Results: Three patients of 10 FDG PET showed abnormal FDG uptake. One had high serum CA 125 levels and high fractions of carcinomatous element on histopathologic examination. FDG PET showed metastatic lesions in unexpected locations, which could not be detected by anatomical images. Another had normal serum CA 125 levels with high sarcomatous element and CT could only detect a few lesions. The other had high serum CA 125 levels and also had high carcinomatous element. Seven patients who had no abnormal uptake on FDG PET had no clinical evidence of recurrence during the follow up period ($51.7{\pm}12.2$ months). The mean disease free intervals of these 7 patients were $36.4{\pm}6.0$ months. Two patients with abnormal findings had never become disease-free condition during the follow up period ($6.0{\pm}4.2$ months. Conclusion: FDG PET could be a useful modality for unexpected distant metastasis and follow up tool in patients with MMMT.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.253-259
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• 2017

The study examines changes in calcium volume on born by comparing two figures; one is measured by dual energy computed tomography(DECT) followed by applying variation in monochromatic energy selection(keV), material decomposition(MD), and material suppressed iodine(MSI) analysis, and the other is measured by conventional single source computed tomography(CSCT). For this study, based on CSCT images taken by using human mimicked phantom, 70, 100, 140 keV and MSI, MD material calcium weighting(MCW) and MD material iodine weighting(MIW) of DECT were applied respectively. Then calculated calcium volume was converted to Agatston score for comparison. Volume of human mimicked phantom was in inverse proportion to keV. The volume decreased while keV increased(p<0.05). The most similar DECT volumes were reconstructed at 70 keV, the difference was showed $35.8{\pm}12.2$ for rib, femur ($16.1{\pm}24.1$), pelvis($13.7{\pm}18.8$), and spine($179.0{\pm}61.8$). However, the volume of MSI was down for each organ; the volume of rib was 5.55%, femur(76.34%), pelvis(55.16%) and spine(87.58%). The volume of MSI decreased 55.9% for rib, femur(80.7%), pelvis(69.6%) and spine(54.2%) while MD MIW reduced for rib(83.51%), femur(87.68%), pelvis(86.64%), and spine(82.62%). With the results, the study found that outcomes were affected by the method which examiners employed. When using DECT, calcium volume of born dropped with keV increased. It also found that the most similar DECT images were reconstructed at 70 keV. The results of experiments implied that the users of MSI and MD should be cautious of errors as there are big differences in scores between those two methods.