• Korean Journal of Radiology
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• 제23권10호
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• pp.959-975
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• 2022

Objective: To investigate the agreement and reliability of estimating the volumes and normative percentiles (N%) of segmented brain regions among NeuroQuant (NQ), DeepBrain (DB), and FreeSurfer (FS) software programs, focusing on the comparison between NQ and DB. Materials and Methods: Three-dimensional T1-weighted images of 145 participants (48 healthy participants, 50 patients with mild cognitive impairment, and 47 patients with Alzheimer's disease) from a single medical center (SMC) dataset and 130 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset were included in this retrospective study. All images were analyzed with DB, NQ, and FS software to obtain volume estimates and N% of various segmented brain regions. We used Bland-Altman analysis, repeated measures ANOVA, reproducibility coefficient, effect size, and intraclass correlation coefficient (ICC) to evaluate inter-method agreement and reliability. Results: Among the three software programs, the Bland-Altman plot showed a substantial bias, the ICC showed a broad range of reliability (0.004-0.97), and repeated-measures ANOVA revealed significant mean volume differences in all brain regions. Similarly, the volume differences of the three software programs had large effect sizes in most regions (0.73-5.51). The effect size was largest in the pallidum in both datasets and smallest in the thalamus and cerebral white matter in the SMC and ADNI datasets, respectively. N% of NQ and DB showed an unacceptably broad Bland-Altman limit of agreement in all brain regions and a very wide range of ICC values (-0.142-0.844) in most brain regions. Conclusion: NQ and DB showed significant differences in the measured volume and N%, with limited agreement and reliability for most brain regions. Therefore, users should be aware of the lack of interchangeability between these software programs when they are applied in clinical practice.

• Korean Journal of Radiology
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• 제21권9호
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• pp.1036-1044
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• 2020

Objective: To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patients with breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventional diffusion-weighted imaging (cDWI). Materials and Methods: Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm² (cDWI₈₀₀ and cDWI₁₅₀₀) and sDWI at b-values of 1000 and 1500 s/mm² (sDWI₁₀₀₀ and sDWI₁₅₀₀). Qualitative analysis (normal glandular tissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI sets and the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI set in 45 patients with the lesion identified on any of the DWI sets. Statistical comparisons were performed using Friedman test, one-way analysis of variance, and Cochran's Q test. Results: All parameters of qualitative analysis, cancer-to-parenchyma contrast ratios, and CDR increased with increasing b-values, regardless of the type of imaging (synthetic or conventional) (p < 0.001). Additionally, sDWI₁₅₀₀ provided better lesion conspicuity than cDWI₁₅₀₀ (3.52 ± 0.92 vs. 3.39 ± 0.90, p < 0.05). Although cDWI₁₅₀₀ showed better normal glandular tissue suppression and overall image quality than sDWI₁₅₀₀ (3.66 ± 0.78 and 3.73 ± 0.62 vs. 3.32 ± 0.90 and 3.35 ± 0.81, respectively; p < 0.05), there was no significant difference in their CDR (90.0%). Cancer-to-parenchyma contrast ratios were greater in sDWI₁₅₀₀ than in cDWI₁₅₀₀ (0.63 ± 0.17 vs. 0.55 ± 0.18, p < 0.001). Conclusion: sDWI₁₅₀₀ can be feasible for evaluating breast cancers in clinical practice. It provides higher tumor conspicuity, better cancer-to-parenchyma contrast ratio, and comparable CDR when compared with cDWI₁₅₀₀.

• 치과방사선
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• 제27권1호
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• pp.217-230
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• 1997

The location of the mandibular canal and the cortical thickness of the mandible is important in the practice of dentistry. This study was performed on twenty chosen dry mandibles, which were of adults and included fully erupted premolars and molars. The purpose of this study was to evaluate the location of the mandibular canal and the cortical thickness of the mandible on computed tomograms and to aid in the surgical treatment plans. The obtained results were as follows; 1. The horizontal distance between the mandibular canal and the buccal external border was 6.6±0.9mm on Somesial root of the first molar), and it was increased posteriorly. The horiwntal distance between the mandibular canal and the lingual external border was 4.1±1.lmm on S/sub 0/, and it was decreased posteriorly. 2. The vertical distance between the alveolar crest and the mandibular canal was 16.9±1.6mm on S/sub 0/, and it was decreased posteriorly. The vertical distance between the inferior border of mandible and the mandibular canal was 8.8±1.3mm on S/sub 0/, and it was increased anteriorly and posteriorly. 3. The thickness of the buccal cortical plate was 2.2±0.4mm on S/sub 0/. and it was increased posteriorly. But, that of the lingual cortical plate was 2.0±0.6mm on S/sub 0/ and it was decreased posteriorly. 4. The area of the buccal cortical plate was 66.5±1.0mm² on S/sub 0/. and it was increased posteriorly. But, that of the lingual cortical plate was 65.8±0.9mm² on S/sub 0/ and it was decreased posteriorly.

• Imaging Science in Dentistry
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• 제34권4호
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• pp.175-178
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• 2004

Purpose: Picture Archiving and Communication System (PACS) is difficult to implement in the best of situations, but evidence is growing that the benefits are significant. The aims of this study are to analyze the current status of full PACS and establish successful installation standard of dental PACS. Materials and Methods : Materials and methods were based on the investigation of current working status and installation standard of PACS, and observation of variable issues to installation of dental PACS. Results: By September 30,2004, full PACS implementations in their facilities were 88.1 % in specialized general hospitals (37 installations out of total 42 hospitals), 59.8% in general hospitals (144 installations out of total 241 hospitals), 12.3% in medical hospitals (116 installations out of total 941 hospitals) and 3.6% in dental hospitals (4 installations out of total 11 0 hospitals) Only 4 university dental hospitals currently have installed and are operating full PACS. Major obstacle to wide spread of dental PACS is initial high investments. Conclusions: Clinical environments of dental PACS differed from medical situation. Because of characteristic dental practice, the initial investments for dental PACS are generally much greater than those of medical PACS. Also new economic crisis makes users scruple. The best way to overcome these limitations is to establish an economic installation standard for dental PACS. Also the clear technical communication between the customer and the supplier before both sides are committed to the obstacles are critical to its success.

• 한국방사선학회논문지
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• 제2권1호
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• pp.11-16
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• 2008

방사선은 의학, 이공학, 농학, 기타 산업분야 등에서 사용영역이 매우 넓고 방사선이용기술의 개발로 방사선의 이용 빈도는 계속 증가되고 있다. 방사선의 인류에 대한 공헌은 지대하지만 생체에 미치는 영향으로 인하여 방사선에 의한 장해 또한 간과할 수 없는 부분이다. 방사선을 유효적절하게 이용하면서 장해를 방지하기 위해서는 방사선을 정확하게 계측하여야 하며 이에 따른 연구와 교육이 철저하게 이루어 져야만 한다. 본 연구에서는 유비쿼터스 컴퓨팅기술을 이용하여 생체에 유해한 작용을 하는 방사선을 방사선선원에 접근하지 않고 무선으로 시간과 장소에 제한 없이 방사선을 계측할 수 있는 방안을 제안하였다. 제안된 방안의 구현은 무선전송 기술은 CDMA망을 이용하였고, 임베디드시스템(embedded system)을 PDA에 내장한 후, 고정된 IP를 가지는 방사선계측시스템에 PDA를 CDMA망에 접속하여 계측값을 디스플레이 하였다. 본 연구에서 제안된 방안을 이용한다면 인간이 유해한 방사선선원에 접근하지 않고 선원에 배치된 고정된 IP를 가지고 있는 방사선계측시스템을 통하여 CDMA망으로 PDA에 표시된 계측값을 읽을 수 있게 될 것이다.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.339-346
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• 2020

Purpose: The purpose of this study was to evaluate the image quality, diagnostic efficacy, and radiation dose associated with the use of a cadmium telluride (CdTe) detector, compared to charge-coupled device (CCD) and complementary metal oxide semiconductor(CMOS) detectors. Materials and Methods: Lateral cephalographs of a phantom (type 1) composed of synthetic polymer filled with water and another phantom (type 2) composed of human skull macerated with polymer coating were obtained with CdTe, CCD, and CMOS detectors. Dosimeters placed on the type 2 phantom were used to measure radiation. Noise levels from each image were also measured. McNamara cephalometric analysis was conducted, the dentoskeletal configurations were assessed, and a subjective evaluation of image quality was conducted. Parametric data were compared via 1-way analysis of variance with the Tukey post-hoc test, with a significance level of 5%. Subjective image quality and dentoskeletal configuration were described qualitatively. Results: A statistically significant difference was found among the images obtained with the 3 detectors(P<0.05), with the lowest noise level observed among the images obtained with the CdTe detector and a higher subjective preference demonstrated for those images. For the cephalometric analyses, no significant difference (P>0.05) was observed, and perfect agreement was seen with regard to the classifications obtained from the images acquired using the 3 detectors. The radiation dose associated with the CMOS detector was higher than the doses associated with the CCD (P<0.05) and CdTe detectors(P<0.05). Conclusion: Considering the evaluated parameters, the CdTe detector is recommended for use in clinical practice.

• 대한핵의학회지
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• 제26권1호
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• pp.95-100
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• 1992

The radioisotopic measurement of glomerular filtration rate (GFR) has required analysis of serial blood or urine samples over several hours, and does not allow measurement of separate renal function unless separate catherterization of individual ureters is done. Gates described isotopic method for the measurement of global and unilateral GFR based on the determination by scintillation camera of the fraction of the injected dose of $^{99m}Tc-diethylenetriaminepentaacetic$ acid (DTPA) present in the kidneys 2-3 minutes after its administration. We calculated GFR according to Gates' method in 58 adult patients with various levels of global renal function using $^{99m}Tc$ DTPA and validated this technique by correlation with 24 hour creatinine clearance. A good correlation was observed between 24 hour creatinine clearance and GFR calculated by Gates' formula, with an r value of 0.91 (p<0.01). We concluded that determination of GFR according to the Gates' formula allows good and reproducible prediction of GFR with great rapidity and simplicity rendering this technique suitable for clinical practice.

• Journal of Animal Science and Technology
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• 제64권5호
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• pp.997-1007
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• 2022

Delayed healing associated with distal limb wounds is highly challenging in equine clinical practice. This study aimed to evaluate healing rates between chronic non-granulating wounds of horse distal limbs that were treated with maltodextrin/ascorbic acid gel alone or in combination with povidone-iodine 1% solution and those treated with povidone-iodine 1% only throughout the study period (35 days) in clinical settings. The study was conducted on 18 adult horses (3-15 years old). Based on the treatment regimen utilized, the horses were divided into three groups (n = 6), with each group having a similar mean wound area. The percentages of wound contraction, epithelialization, and overall wound healing were determined weekly for each wound. By the end of the study, the total wound healing percentage was significantly increased between the study groups (p < 0.05). The use of maltodextrin/ascorbic acid gel resulted in considerable wound contraction, rapid epithelialization, and complication-free wound healing. Based on the findings of this study, maltodextrin/ascorbic acid gel, independently or in combination with a 1% povidone-iodine solution, might be applied as a safe and effective wound healing promoting agent in horses with chronic non-granulating wounds.

• Investigative Magnetic Resonance Imaging
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• 제21권3호
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• pp.195-198
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• 2017

Idiopathic brain herniation is a rare condition. We believe that this is the first reported case of idiopathic herniation of the lingual gyrus. The case involves a 57-year-old woman presenting with frontal headache without overt visual symptoms. Magnetic resonance imaging (MRI) revealed an idiopathic herniation of the lingual gyrus of the occipital lobe extending into the quadrigeminal cistern. No other adjacent intracranial abnormalities were observed. Although some conditions may be considered in the differential diagnosis, accurate diagnosis of idiopathic brain herniation in medical practice can prevent unnecessary additional imaging procedures and invasive open biopsy in patients with typical imaging findings.

• Tuberculosis and Respiratory Diseases
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• 제78권3호
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• pp.180-189
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• 2015

Accurate lymph node staging of lung cancer is crucial in determining optimal treatment plans and predicting patient outcome. Currently used lymph node maps have been reconciled to the internationally accepted International Association for the Study of Lung Cancer (IASLC) map published in the seventh edition of TNM classification system of malignant tumours. This article provides computed tomographic illustrations of the IASLC nodal map, to facilitate its application in day-to-day clinical practice in order to increase the appropriate classification in lung cancer staging.