• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.366-370
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• 2006

Arachnoid cysts are intra-arachnoid collections of cerebrospinal fluid. They may cause neurological deficit through expansion that can compress normal neural tissue and obstruct cerebrospinal fluid flow. Intracranial arachnoid cysts were found in 4 patients aged 10 months to 20 months(mean age 15 months). The presenting symptoms included circling(dog 2,3), seizure(dog 1), progressive weakness(dog 1,2,3), increasing scoliosis(dog 3), worsening spasticity(dog 3), and salivation(dog 3). One patient showed no symptoms from the intracranial arachnoid cyst. There were no significant findings in complete blood count and serum chemistry. Computed tomography(CT) with/without magnetic resonance imaging(MRI) scans were performed in these cases. Hypodense intracranial arachnoid cyst was observed on CT images in dog 4. Sagittal T1-weighted(T1W) and T2-weighted(T2W) images and transverse T1W and T2W images revealed a intracranial arachnoid cysts with syringohydromyelia(dog 3) and hydrocephalus(dog 3,4) in the brain. Clinical signs of three cases were improved by medication.

• Nutrition Research and Practice
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• v.4 no.2
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• pp.128-135
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• 2010

Obesity was characterized in Korean elementary students using different obesity assessment tests on 103 overweight elementary students from three schools of Jeonbuk Province. The body mass index (BMI) and obesity index (OI) were compared, and the data using DEXA and CT were compared with the data using BIA and a tape measure. The results of this study are as follows: first, 27 students who were classified as obese by OI were classified as overweight by BMI, and 3 students who were classified as standard weight by BMI were classified as overweight by OI. Secondly, by DEXA and BIA measurements, there was 1.51% difference in body fat percentage (boys 1.66%, girls 1.17%) and the difference in body fat mass between boys and girls was 0.77 kg (boys 0.85 kg, girls 0.59 kg), but those differences in body fat percentage and mass were not statistically significant. Thirdly, the average total abdominal fat (TAF) measured by CT scans of obese children was more significantly related with subcutaneous fat (r = 0.983, P < 0.01) than visceral fat (r = 0.640, P < 0.01). Also, TAF were highest significant with waist circumference by a tape measure (r = 0.744, P < 0.01). In summary, as there are some differences of assessment results between two obesity test methods (BMI, OI), we need more definite standards to determine the degree of obesity. The BIA seems to be the most simple and effective way to measure body fat mass, whereas waist/hip ratio (WHR) using a tape measurer is considered to be the most effective method for assessing abdominal fat in elementary students.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.467-473
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• 2005

Calvarial bone grafting in craniomaxillofacial trauma and facial reconstructive surgery is now widely recognized and accepted as a standard procedure. One of the commonly reported problems of calvarial bone graft is the contour defect caused by partial resorption of the graft. But, there are few reports that discuss the fate of the calvarial bone graft based on the quantitative data. In this article, the changes of grafted calvarial bone were evaluated using 3-dimensional computed tomography(CT). 9 patients were observed with the CT scans at 2mm thickness immediately after operation and at the time of last follow-up. The area of the bone defect was segmented on the 3-dimensional CT image and calculated by AnalyzeDirect 5.0 software. The immediate postoperative bone defect area of the recipient site and the donor site were $612.9mm^2$ and $441.5mm^2$, respectively, which became $1028.1mm^2$ and $268.8mm^2$, respectively at the last follow-up. In conclusion, the bone defect area was less increased on the donor site of calvarial bone graft than on the recipient site. And the CT scan is a valuable imaging method to assess and follow-up the clinical outcome of calvarial bone grafting.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.262-269
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• 2010

Introduction: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. Materials and Methods: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. Results: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. Conclusion: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.

• Radiation Oncology Journal
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• v.2 no.2
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• pp.287-297
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• 1984

The normal intracranial structures are relatively resistant to therapeutic radiation, but may react adversely in a variety of ways, and the damage to nerve tissue may be slow in making its appearance, and once damage has occured the patient recovers slowly and incompletly. Therefore, it is important to consider the possibility of either recurrent tumor or late adverse effect in any patient who has had radiotherapy. The determination o( rnorphological/pathological correlation is very important to the therapeutic radiologist who uses CT scans to define a treatment volume, as well as to the clinician who wishes to explain the patient's clinical state in terms of regress, progression, persistence, or recurrence of tumor or radiation-induced edema or necrosis, The authors are obtained as following results ; 1. The field size(whole CNS, large, intermediate, small field) was variable according to the location and extension of tumor and histopathologic diagnosis, and the tatal tumor dose was 4,000 to 6,000 rads except one of recurred case of 9,100 rads. The duration of follow up CT scan was from 3 months to 5 year 10 months. 2, The histopathologic diagnosis of 9cases were glioblastoma multiforme(3 cases), pineal tumor (3), oligodendroglioma (1), cystic astrocytoma (1), pituitary adenoma (1) and their adverse effects after radiation therapy were brain atrophy (4 cases) , radiation necrosis(2), tumor recurrence with or without calcification (2), radiation·induced infarction (1). 3. The recurrent symptoms after radiation therapy of brain tumor were not always the results of regrowth of neoplasm, but may represent late change of irradiated brain. 4. It must be need that we always consider the accurate treatment planning and proper treatment method to reduce undesirable late adverse effects in treatment of brain tumors.

• Korean Journal of Clinical Pharmacy
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• v.26 no.1
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• pp.40-45
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• 2016

Objective: The increasing use of imaging examinations such as computed tomography (CT) results in increased contrast media use, which increases contrast media-induced adverse reactions (AR). This study investigated the risk factors of ARs to nonionic iodinated contrast media. Methods: This study evaluated patients who were administered iodinated contrast media during CT scanning in Yeouido St. Mary's Hospital in Seoul, Korea in 2012. Among the subjects, those with contrast media-induced ARs were classified as the AR group. The control group included individuals without ARs who were selected through simple random sampling. The effects of sex, age, contrast media type and dose, CT region, previous contrast media administration, allergy history, and comorbidity were analyzed in the AR and control groups. Results: Multivariate logistic regression analyses were performed to evaluate the identified AR risk factors in 103 subjects in the AR group and 412 subjects in the control group. The results confirmed that the risk of developing ARs was significantly higher in females [odds ratio (OR): 2.206; 95% confidence interval (CI): 1.353-3.598], in individuals administered Iohexol (OR: 9.981; 95% CI: 2.361-42.193), in individuals with an allergy history (OR: 3.982; 95% CI: 1.742-9.101), and in individuals with comorbid asthma (OR: 6.619; 95% CI: 1.377-31.826). Most of the ARs were mild and immediate. Conclusion: In patients who were administered contrast media during CT scans, female gender, Iohexol use, allergy history, and asthma were risk factors for ARs. Therefore, special care is required for patients with such risk factors to prevent ARs.

• Journal of Korean Neurosurgical Society
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• v.44 no.3
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• pp.124-130
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• 2008

Objective : Our purpose of this study is to compare insertion angles and screw lengths from Roy-Camille, Magerl, and our designed method for cervical lateral mass screw fixation in the Korean population by quantitative measurement of reformatted two dimensional (2D) computed tomography (CT) images. Methods : We selected thirty Korean patients who were evaluated with thin section CT scans and reconstruction program to obtain reformatted 2D-CT images of the transversal plane passing the cranio-caudal angle using three different techniques. We measured the minimum angle to avoid vertebral artery (VA) injury, the ideal angle and depth for bicortical screwing of cervical lateral mass. Morphometric measurements of the lateral masses from C3-C7 were also taken. Results : In all three techniques, the mean safety angles from the VA were less than 8 degrees and the necessary depth of the screw was about 14 mm for safety to the VA and for the bicortical purchase. In our designed technique, the mean $\beta$ angles of each level from C3 to C7 were 29.0. 29.8. 29.5. 26.3. and 23.9 degrees, respectively. Conclusion : Results of this study and data from the literature indicate that differences may exist between the Korean and Western people in the length and angle for ideal lateral mass screw fixation. In addition, our technique needs further cadaveric and clinical study for safety and efficacy for being performed as alternative method for cervical lateral mass fixation.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.268-272
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• 2013

The purpose of this study was to assess the effects of reconstruction kernel, and slice thickness on the accuracy of spiral CT-based volume assessment over a range of object sizes typical of synthetic simulated tumor. Spiral CT scanning was performed at various reconstruction kernels (soft tissue, standard, bone), and slice thickness (1, 2, 3 mm) using a phantom made of gelatin and 10 synthetic simulated tumors of different sizes (diameter 3.0-12.0 mm). Three-dimensional volume assessments were obtained using an automated software tool. Results were compared with the reference volume by calculating the percentage error. Statistical analysis was performed using ANOVA and setting statistical significance at P < 0.05. In general, smaller slice thickness and larger sphere diameters produced more accurate volume assessment than larger slice thickness and smaller sphere diameter. The measured volumes were larger than the actual volumes by a common factor depending on slice thickness; in 100HU simulated tumors that had statistically significant, 1 mm slice thickness produced on average 27.41%, 2 mm slice thickness produced 45.61%, 3 mm slice thickness produced 93.36% overestimates of volume. However, there was no statistically significant difference in volume error for spiral CT scans taken with techniques where only reconstruction kernel was changed. These results supported that synthetic simulated tumor size, slice thickness were significant parameters in determining volume measurement errors. For an accurate volumetric measurement of an object, it is critical to select an appropriate slice thickness and to consider the size of an object.

• Korean Journal of Radiology
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• v.23 no.7
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• pp.752-762
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• 2022

Objective: To compare a deep learning-based reconstruction (DLR) algorithm for pediatric abdominopelvic computed tomography (CT) with filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Materials and Methods: Post-contrast abdominopelvic CT scans obtained from 120 pediatric patients (mean age ± standard deviation, 8.7 ± 5.2 years; 60 males) between May 2020 and October 2020 were evaluated in this retrospective study. Images were reconstructed using FBP, a hybrid IR algorithm (ASiR-V) with blending factors of 50% and 100% (AV50 and AV100, respectively), and a DLR algorithm (TrueFidelity) with three strength levels (low, medium, and high). Noise power spectrum (NPS) and edge rise distance (ERD) were used to evaluate noise characteristics and spatial resolution, respectively. Image noise, edge definition, overall image quality, lesion detectability and conspicuity, and artifacts were qualitatively scored by two pediatric radiologists, and the scores of the two reviewers were averaged. A repeated-measures analysis of variance followed by the Bonferroni post-hoc test was used to compare NPS and ERD among the six reconstruction methods. The Friedman rank sum test followed by the Nemenyi-Wilcoxon-Wilcox all-pairs test was used to compare the results of the qualitative visual analysis among the six reconstruction methods. Results: The NPS noise magnitude of AV100 was significantly lower than that of the DLR, whereas the NPS peak of AV100 was significantly higher than that of the high- and medium-strength DLR (p < 0.001). The NPS average spatial frequencies were higher for DLR than for ASiR-V (p < 0.001). ERD was shorter with DLR than with ASiR-V and FBP (p < 0.001). Qualitative visual analysis revealed better overall image quality with high-strength DLR than with ASiR-V (p < 0.001). Conclusion: For pediatric abdominopelvic CT, the DLR algorithm may provide improved noise characteristics and better spatial resolution than the hybrid IR algorithm.

• Korean Journal of Radiology
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• v.22 no.11
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• pp.1797-1808
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• 2021

Objective: To determine whether volumetric CT texture analysis (CTTA) using fully automatic tumor segmentation can help predict recurrence-free survival (RFS) in patients with intrahepatic mass-forming cholangiocarcinomas (IMCCs) after surgical resection. Materials and Methods: This retrospective study analyzed the preoperative CT scans of 89 patients with IMCCs (64 male; 25 female; mean age, 62.1 years; range, 38-78 years) who underwent surgical resection between January 2005 and December 2016. Volumetric CTTA of IMCCs was performed in late arterial phase images using both fully automatic and semi-automatic liver tumor segmentation techniques. The time spent on segmentation and texture analysis was compared, and the first-order and second-order texture parameters and shape features were extracted. The reliability of CTTA parameters between the techniques was evaluated using intraclass correlation coefficients (ICCs). Intra- and interobserver reproducibility of volumetric CTTAs were also obtained using ICCs. Cox proportional hazard regression were used to predict RFS using CTTA parameters and clinicopathological parameters. Results: The time spent on fully automatic tumor segmentation and CTTA was significantly shorter than that for semi-automatic segmentation: mean ± standard deviation of 1 minutes 37 seconds ± 50 seconds vs. 10 minutes 48 seconds ± 13 minutes 44 seconds (p < 0.001). ICCs of the texture features between the two techniques ranged from 0.215 to 0.980. ICCs for the intraobserver and interobserver reproducibility using fully automatic segmentation were 0.601-0.997 and 0.177-0.984, respectively. Multivariable analysis identified lower first-order mean (hazard ratio [HR], 0.982; p = 0.010), larger pathologic tumor size (HR, 1.171; p < 0.001), and positive lymph node involvement (HR, 2.193; p = 0.014) as significant parameters for shorter RFS using fully automatic segmentation. Conclusion: Volumetric CTTA parameters obtained using fully automatic segmentation could be utilized as prognostic markers in patients with IMCC, with comparable reproducibility in significantly less time compared with semi-automatic segmentation.