Earticle

Nowadays, X-ray computed tomography (CT) wood nondestructive testing technology has been applied to detection of internal defects in log for the purpose of obtaining the optimal wood cutting plan. Multifractal spectrum and wavelet transform are usually used for analyzing, modeling, and extracting different complex features of signals and images. A novel CT image edge detection method which using multifractal spectrum theory combined with wavelet transform is applied in this paper. The new method can be divided into the following main steps: (1) Calculating the wavelet module values of wood defect image. (2) Combining wavelet transform module values with multifractal theory. (3) Calculating the multifractal spectrum from the wavelet transform. (4) Selecting the appropriate threshold to wood defects detection. A large number of experimental results show that the new method to recognize the wood defects is effective.

This paper proposes an automatic lung lobe segmentation method in a supervised way. The lung image is given as input and the lung image is segmented using iterative threshold method. Then fissure information is enhanced using log supportive filter. Then Fissure locations are extracted using Vector training and matching process. Finally the lung lobes are segmented and marked as individual lobes. The main modules of this proposed method are Iterative threshold based lung segmentation, Fissure enhancement, fissure detection and Lung lobe segmentation. This proposed method can be used to find the missing fissures and unclear fissures also. This proposed method is working based on training of fissure information and detection is done according to the trained vectors. The proposed method segments the lung lobes with high performance and high speed.

Objectives : This study was conducted to compare between hallucination group and delusion group in patient with schizophrenia, using Brain $^{99m}Tc$-ECD PECT. Methods : Among 16 patients with less than 3 schizophrenic episodes, 8 patients whose initial symptom was hallucination were assigned to the hallucination group, and other 8 patients with initial sumptom of delusion were assinged to the hallucination group. All of the patients clinically evaluated using the PANSS and BPRS. Both groups of patients and 8 healthy subjects underwent $^{99m}Tc$-ECD PECT. Results : Score of thinking disturbance subscale of BPRS were significantly lower in the hallucination group than the delusion group. In SPECT analysis, the hallucination group showed significantly increased perfusion in some areas of the right temporal lobe, bilateral limbic lobes and left parietal lobe compared to delusion group. Both group had a reduced rCBF in some areas of the frontal lobe. Conclusion : The hallucniation group, compared with the delusion group, showed significantly increased regional cerebral blood flow in some regions. Therefore, this data suggests that different neural substrates may affect the process of auditory hallucination and delusion.

과도한 마모는 치료받지 않을 시 여러 문제점들을 야기시킬 수 있기 때문에, 정확한 분석 및 진단을 바탕으로 예지성 있는 치료계획을 수립하도록 노력해야 하고, 수직고경에 대한 평가 및 그에 따른 단계적인 치료를 통해 안정된 악간 관계를 회복시켜 주어야 한다. 또한 임플란트 치료의 장기적인 성공을 위해서는 이상적인 위치와 각도로 임플란트를 식립하는 것이 중요하며, 다수의 임플란트 치료에서는 그 중요성이 더욱 증가한다. 따라서 철저한 계획 및 진단에 따른 정확한 수술과 보철 과정이 중요하다. 본 증례에서는 다수의 치아 상실 및 전반적인 치아 마모로 인해 수직고경이 상실되어 있는 68세의 남자 환자에게 치료 전 단계에서부터 다양하고 체계적인 분석을 통해 수직고경을 회복하는 치료 계획을 세웠다. 콘빔컴퓨터단층촬영 데이터를 활용하여 새로 설정한 수직고경에 맞춰 가이드 수술을 시행하였고, 임플란트를 포함한 전악 고정성 보철 수복을 통해 기능 및 심미적으로 환자와 술자 모두 만족할 만한 결과를 얻었기에 이를 보고하고자 한다.

Excessive wear causes many complications when untreated, so that accurate diagnosis, analysis and predictive treatment plan should be made, and through evaluation of vertical dimension and stepwise treatment, a stable inter-arch relationship can be set. For the long-term success of implant treatment, ideal position and angle of implant is important, and its importance increases especially in multiple implant cases. Therefore, thorough diagnosis and planning, accurate surgery and prosthodontic procedures are significant. In this case, a 68-year-old male patient with a loss of vertical dimension due to multiple tooth loss and overall tooth wear was planned with systematic analyses from the pre-treatment stage to rehabilitate vertical dimension. Full-mouth fixed rehabilitation with computer tomography guided implant surgery was performed to the newly set vertical dimension and attained satisfactory outcomes both functionally and esthetically.

Aim: This study aims to investigate the manifestation of CT, MRI and dynamic enhanced scans for primary hepatic neuroendocrine cell carcinoma. Methods: CT or MRI arterial and venous phase scan images of 19 cases of pathologically confirmed PHNEC were retrospectively analyzed. Results: 14 cases (73.68%) with single lesion, 5 cases (26.3%) with multiple lesions, with an average diameter of 13.2 cm. Some 12 cases (63.16%) showed inhomogeneous enhancement, seven cases (36.8%) showed homogeneous enhancement, 13 cases (68.4%) demonstrated significant enhancement in the arterial phase, 13 cases (68.4%) had significantly enhanced portal venous phase including 7 cases (36.8 %) with portal venous phase density or signal above the arterial phase and 5 cases (26.3%) with the portal vein density or signal below the arterial phase. Seven cases (36.8%) had continued strengthened separate shadows in the center of the lesion. Thrombosis were not seen in portal veins. Conclusion: CT and MRI images of liver cell neuroendocrine carcinoma have certain characteristics that can provide valuable information for diagnosis and differential diagnosis.

Human influence on soil formation has dramatically increased as the development of human civilization and industry. Increase of anthropogenic soils induced research of those soils; classification, chemical and physical characteristics and plant growth of anthropogenic soils. However there have been no reports on soil pore properties from the anthropogenic soils so far. Therefore the objectives of this study were to test computer tomography (CT) to characterize physical properties of an anthropogenic paddy field soil and to find differences between natural and anthropogenic paddy field soils. Soil samples of a natural paddy field were taken from Ansung, Gyeonggi-do (Ansung site), and samples of an anthropogenic paddy field were from Gumi in Gyeongsangnam-do (Gasan) where paddy fields were remodeled in 2011-2012. Samples were taken at three different depths and analyzed for routine physical properties and CT scans. CT scan provided 3 dimensional images to calculate pore size, length and tortuosity of soil pores. Fractal analysis was applied to quantify pore structure within soil images. The results of measured physical properties (bulk density, porosity) did not show differences across depths and sites, but hardness and water content had differences. These differences repeated within the results of pore morphology. Top soil samples from both sites had greater pore numbers and sizes than others. Fractal analyses showed that top soils had more heterogeneous pore structures than others. The bottom layer of the Gasan site showed more degradation of pore properties than ploughpan and bottom layers from the Ansung site. These results concluded that anthropogenic soils may have more degraded pore properties as depth increases. The remodeled paddy fields may need more fundamental remediation to improve physical conditions. This study suggests that pore analyses using CT can provide important information of physical conditions from anthropogenic soils.

Background: Hepatocellular carcinomas (HCCs) less than 2 cm in diameter generally demonstrate a good outcome after curative therapy. However, the diagnosis of small HCC can be problematic and requires one or more dynamic imaging modalities. This study aimed to compare the sensitivity and agreement between CT and MRI for the diagnosis of small HCCs. Methods: CT and/or MRI scans of HCCs (1-2 cm) diagnosed by histopathology or typical vascular pattern according to the 2005 AASLD criteria were blindly reviewed by an abdominal radiologist. The reports were defined as conclusive/typical when arterial enhancement and washout during the portal/delayed phases were observed and as inconclusive when typical vascular patterns were not observed. The sensitivity and Cohen's kappa (k) for agreement were calculated. Results: In 27 patients, 27 HCC nodules (1-2 cm) were included. Diagnosis with a single-imaging modality (CT or MRI) was 81 % versus 48 % (p = 0.01). The CT sensitivity was significantly higher than MRI (78 % versus 52 %, p = 0.04). Among 27 nodules that underwent both CT and MRI, a discordance in typical enhancement patterns was found (k = 0.319, p = 0.05). In cases with inconclusive CT results, MRI gave only an additional 3.7 % sensitivity to reach a diagnosis. In contrast, further CT imaging following inconclusive MRI results gave an additional 29.6 % sensitivity.Conclusions: A single typical imaging modality is sufficient to diagnose small HCCs. Compared with MRI, multiphasic CT has a higher sensitivity. The limitations of MRI could be explained by the greater need for patient cooperation and the types of MRI contrast agent.

Objective: The purpose of this study was to evaluate computed tomography (CT) virtual non-contrast (VNC) spectral imaging for gastric carcinoma. Materials and Methods: Fifty-two patients with histologically proven gastric carcinomas underwent gemstone spectral imaging (GSI) including non-contrast and contrast-enhanced hepatic arterial, portal venous, and equilibrium phase acquisitions prior to surgery. VNC arterial phase (VNCa), VNC venous phase (VNCv), and VNC equilibrium phase (VNCe) images were obtained by subtracting iodine from iodine/water images. Images were analyzed with respect to image quality, gastric carcinoma-intragastric water contrast-to-noise ratio (CNR), gastric carcinoma-perigastric fat CNR, serosal invasion, and enlarged lymph nodes around the lesions. Results: Carcinoma-water CNR values were significantly higher in VNCa, VNCv, and VNCe images than in normal CT images (2.72, 2.60, 2.61, respectively, vs 2.35, $p{\leq}0.008$). Carcinoma-perigastric fat CNR values were significantly lower in VNCa, VNCv, and VNCe images than in normal CT images (7.63, 7.49, 7.32, respectively, vs 8.48, p< 0.001). There were no significant differences of carcinoma-water CNR and carcinoma-perigastric fat CNR among VNCa, VNCv, and VNCe images. There was no difference in the determination of invasion or enlarged lymph nodes between normal CT and VNCa images. Conclusions: VNC arterial phase images may be a surrogate for conventional non-contrast CT images in gastric carcinoma evaluation.

The aim of this series of experiments was to examine the opportunity for application of X-ray computer tomography (CT) in cattle production. Firstly, tissue composition of M. longissimus dorsi (LD) cuts between the $11-13^{th}$ ribs (in Exp 1. between the $9-11^{th}$ ribs), was determined by CT and correlated with tissue composition of intact half carcasses prior to dissection and tissue separation. Altogether, 207 animals of different breeds and genders were used in the study. In Exp. 2 and 3, samples were taken from LD cuts, dissected and chemical composition of muscle homogenates was analysed by conventional procedures. Correlation coefficients were calculated among slaughter records, tissues in whole carcasses and tissue composition of rib samples. Results indicated that tissue composition of rib samples determined by CT closely correlated with tissue composition results by dissection of whole carcasses. The findings revealed that figures obtained by CT correlate well with the dissection results of entire carcasses (meat, bone, fat). Close three-way coefficients of correlation (r = 0.80-0.97) were calculated among rib eye area, volume of cut, pixel-sum of adipose tissue determined by CT and intramuscular fat or adipose tissue in entire carcasses. Estimation of tissue composition of carcasses using equations including only CT-data as independent variables proved to be less reliable in prediction of lean meat and bone in carcass ($R^2 = 0.51-0.86$) than for fat (($R^2 = 0.83-0.89$). However, when cold half carcass weight was also included in the equation, the coefficient of determination exceeded $R^2 = 0.90$. In Exp. 3 tissue composition of rib samples by CT were compared to the results of EUROP carcass classification. Findings revealed that CT analysis has higher predictive value in estimation of actual tissue composition of cattle carcasses than EUROP carcass classification.

Statement of problem. Relatively low success rate of root analogue implant system was supposed to be due to the time duration between extraction and implant installation. The use of three-dimensional computer tomography and the reconstruction of objects using rapid prototyping methods would be helpful to shorten this time. Purpose. This aim of this study was to evaluate the application possibility of the 3-dimensional computer tomography and the rapid prototyping to root analogue implants. Material and methods. Ten single rooted teeth were prepared. Width and height of the teeth were measured by the marking points. This was followed by CT scanning, data conversion and rapid prototyping model fabrication. 2 methods were used; fused deposition modelling and stereolithography. Same width and height of this models were measured and compared to the original tooth. Results. Fused deposition modelling showed an enlarged width and reduced height. The stereolithography showed more exact data compared with the fused deposition modelling. Smaller standard deviation were recorded in the stereolithographic method. Overall width error from tooth to rapid prototyping was 7.15% in fused deposition modelling and 0.2% in stereolithography. Overall height showed the tendency of reducing dimensions. Conclusion. From the results of this study, stereolithography seems to be very predictable method of fabricating root analogue implant.

Objective: The aim of this study was to compare the accuracy of Bolton analysis obtained from digital models scanned with the Ortho Insight three-dimensional (3D) laser scanner system to those obtained from cone-beam computed tomography (CBCT) images and traditional plaster models. Methods: CBCT scans and plaster models were obtained from 50 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner; Bolton ratios were calculated with its software. CBCT scans were imported and analyzed using AVIZO software. Plaster models were measured with a digital caliper. Data were analyzed with descriptive statistics and the intraclass correlation coefficient (ICC). Results: Anterior and overall Bolton ratios obtained by the three different modalities exhibited excellent agreement (> 0.970). The mean differences between the scanned digital models and physical models and between the CBCT images and scanned digital models for overall Bolton ratios were $0.41{\pm}0.305%$ and $0.45{\pm}0.456%$, respectively; for anterior Bolton ratios, $0.59{\pm}0.520%$ and $1.01{\pm}0.780%$, respectively. ICC results showed that intraexaminer error reliability was generally excellent (> 0.858 for all three diagnostic modalities), with < 1.45% discrepancy in the Bolton analysis. Conclusions: Laser scanned digital models are highly accurate compared to physical models and CBCT scans for assessing the spatial relationships of dental arches for orthodontic diagnosis.

The purpose of this study is to clarify the mechanical behavior of human lumbar vertebrae (L3/L4) with and without fusion bone under physiological axial compression. The author has developed the program code to build the patient specific three-dimensional geometric model from the computed tomography (CT) images. The developed three-dimensional model provides the necessary information to the physicians and surgeons to visually interact with the model and if needed, plan the way of surgery in advance. The processed data of the model is versatile and compatible with the commercial computer aided design (CAD), finite element analysis (FEA) software and rapid prototyping technology. The actual physical model is manufactured using rapid prototyping technique to confirm the executable competence of the processed data from the developed program code. The patient specific model of L3/L4 vertebrae is analyzed under compressive loading condition by the FEA approach. By varying the spacer position and fusion bone with and without pedicle instrumentation, simulations were carried out to find the increasing axial stiffness so as to ensure the success of fusion technique. The finding was helpful in positioning the fusion bone graft and to predict the mechanical stress and deformation of body organ indicating the critical section.

Purpose: To calculate the effective doses of cone-beam computed tomography (CBCT) using personal computer-based Monte Carlo (PCXMC) software (Radiation and Nuclear Safety Authority, Helsinki, Finland) and to compare the calculated effective doses with those measured using thermoluminescent dosimeters (TLDs) and an anthropomorphic phantom. Materials and Methods: An Alphard VEGA CBCT scanner (Asahi Roentgen Ind. Co., Kyoto, Japan) with multiple fields of view (FOVs) was used for this study. The effective doses of the scout and main projections of CBCT using 1 large and 2 medium FOVs with a height >10 cm were calculated using PCXMC and PCXMCRotation software and then were compared with the doses obtained using TLD-100 LiF and an anthropomorphic adult human male phantom. Furthermore, it was described how to determine the reference points on the Y- and Z-axes in PCXMC, the important dose-determining factors in this software. Results: The effective doses at CBCT for 1 large ($20.0cm{\times}17.9cm$) and 2 medium FOVs ($15.4cm{\times}15.4cm$ and $10.2cm{\times}10.2cm$) calculated by the PCXMC software were 181, 300, and $158{\mu}Sv$, respectively. These values were comparable (16%-18% smaller) to those obtained through TLD measurements in each mode. Conclusion: The use of PCXMC software could be an alternative to the TLD measurement method for effective dose estimation in CBCT with large and medium FOVs.

The brain is the body's most organized and controlled organ, and it governs various psychological and mental functions. A brain abnormality could greatly affect one's physical and mental abilities, and consequently one's social life. Brain disorders can be broadly categorized into three main afflictions: stroke, brain tumor, and dementia. Among these, stroke is a common disease that occurs owing to a disorder in blood flow, and it is accompanied by a sudden loss of consciousness and motor paralysis. The main types of strokes are infarction and hemorrhage. The exact diagnosis and early treatment of an infarction are very important for the patient's prognosis and for the determination of the treatment direction. In this study, texture features were analyzed in order to develop a prototype auto-diagnostic system for infarction using computer auto-diagnostic software. The analysis results indicate that of the six parameters measured, the average brightness, average contrast, flatness, and uniformity show a high cognition rate whereas the degree of skewness and entropy show a low cognition rate. On the basis of these results, it was suggested that a digital CT image obtained using the computer auto-diagnostic software can be used to provide valuable information for general CT image auto-detection and diagnosis for pre-reading. This system is highly advantageous because it can achieve early diagnosis of the disease and it can be used as supplementary data in image reading. Further, it is expected to enable accurate medical image detection and reduced diagnostic time in final-reading.