• 말소리와 음성과학
• /
• 제15권4호
• /
• pp.53-60
• /
• 2023

본 연구에서는 음성장애 환자에서 음성 범위 프로파일(voice range profile, VRP)과 말 범위 프로파일(speech range profile, SRP)을 이용한 추정 발화 기본주파수 절대 오차(absolute error of estimated speaking fundamental frequency, AEF0)를 음성장애의 병인 집단 간에 비교하여 차이를 확인하고,각 병인 집단 별로 AEF0와 관련된 변수들 간의 상관관계를 살펴보고자 하였다. 연구대상은 음성장애로 진단된 기능적(functional, FUNC), 기질적(organic, ORGAN), 신경학적(neurogenic, NEUR) 음성장애 환자군과 정상군(normal control, NC) 각 30명(남 15명, 여 15명)으로 총 120명이었다. 각 대상자로 하여금 음성, 말 범위 프로파일 과제를 수행하도록 하고 전기성문파형검사(electroglottography, EGG)를 통해 발화 기본주파수를 측정하였다. 병인 집단 간 AEF0의 비교 결과, Grade와 Severity는 병인 집단 간 차이가 없었던 반면, AEF0_VRP와 AEF0_SUM에서 병인 집단 간 차이가 있어 AEF0_VRP는 ORGAN이 FUNC와 NC보다 높았으며, AEF0_SUM은 ORGAN이 NC보다 높았다. 또한 FUNC와 NEUR에서는 AEF0가 Grade와 양의 상관관계를 보인 반면, ORGAN은 CQ(closed quotient)와 양의 상관관계가 있었다. 따라서 병인 집단에 따라 AEF0의 적용과 관련 음성 변수를 살펴보는 데 주의를 기울여야 할 것으로 보이며, 본 연구는 이러한 임상적 판단에 대한 기초 자료를 마련하는 데 일조한 것으로 여겨진다.

• 대한심미치과학회지
• /
• 제32권2호
• /
• pp.54-68
• /
• 2023

디지털 방법을 사용한 무치악의 임플란트 치료계획은 surgical guide design으로 구체화된다. Surgical guide를 제작할 때, 우리는 먼저 최종 보철의 형태를 가상공간에 구현한 후 이를 바탕으로 식립 계획을 구체화하게 된다. 그러나 완전무치악 환자는 치아배열의 기준이 없고 악간관계가 정립되어 있지 않아 최종 보철의 형태를 짐작하기 어려워 surgical guide를 만드는 데 어려움이 있다. 이때 기존의 만족스러운 총의치나 부분의치, 잔존치 등이 존재한다면 그 치아배열이 가상적인 최종 보철의 reference가 될 수 있다. 만약 이러한 reference가 부재하거나 만족스럽지 못하다면, 진단용 목적으로 총의치를 제작하되 이를 구내에서 검증하는 과정이 필요하다. 이러한 과정을 통해 surgical guide를 제작할지라도 구내 상황에 따라 implant의 위치가 계획한 것과 다르게 식립될 수 있으며, 만약 guide의 positioning이 잘못된다면 그 오차는 모든 implant의 위치를 변위시킬 수 있으므로 guide 수술이 오히려 재앙으로 다가올 수 있다. 본 기고에서는 치아 배열의 reference가 될 수 있는 자료들을 적절한 시기에 채득하여 이를 디지털 공간에 이전 및 통일된 좌표계로 정렬하는 방법에 대해 논의하고, 또한 이렇게 수립된 식립계획을 현실의 구강에 적은 오차로 이전 및 정렬하는 방법에 대해 소개하여 일관적이고 체계적인 무치악 가이드 디자인의 프로토콜 정립에 대해 의견 개진하려 한다.

• 대한기관윤리심의기구협의회지
• /
• 제6권1호
• /
• pp.17-31
• /
• 2024

Purpose: This study aims to develop preliminary items for measuring the perceived service quality of clinical trials among participants and to verify content validity. Methods: This study was designed as a methodological study. A conceptual framework was established based on Brady and Cronin's hierarchical model, and preliminary items were prepared through translation-back-translation, a review of existing instruments, and in-depth interviews with clinical trial participants and clinical research coordinators. The final items were completed through content validity testing by experts and a review of items by clinical trial participants for the prepared preliminary items. Results: Through this study, a set of 58 items across four domains (quality of interaction with researchers, the physical environment, performance procedures, and performance results) and 9 components (information·education·communication, trust, respect for participant preferences, securing facilities and space, accessibility, comfortability, informed consent, coordination of care, subjective understanding of clinical trials) on the service quality of clinical trials were completed. The scale content validity index of all preliminary items was 0.96, meeting the recommended standards. The individual-item content validity index also meets the recommended criteria for most items, excluding four items. Conclusion: This study holds significance in developing items to measure the quality of clinical trial execution from the perspective of participants. By verifying the reliability and validity of these items through subsequent research, it is expected that they can be utilized as a valuable instrument to devise strategies for improving the quality of clinical trials.

• Journal of Gastric Cancer
• /
• 제24권2호
• /
• pp.172-184
• /
• 2024

Purpose: The original eCura system was designed to stratify the risk of lymph node metastasis (LNM) after endoscopic resection (ER) in patients with early gastric cancer (EGC). We assessed the effectiveness of a modified eCura system for reflecting the characteristics of undifferentiated-type (UD)-EGC. Materials and Methods: Six hundred thirty-four patients who underwent non-curative ER for UD-EGC and received either additional surgery (radical surgery group; n=270) or no further treatment (no additional treatment group; n=364) from 18 institutions between 2005 and 2015 were retrospectively included in this study. The eCuraU system assigned 1 point each for tumors >20 mm in size, ulceration, positive vertical margin, and submucosal invasion <500 ㎛; 2 points for submucosal invasion ≥500 ㎛; and 3 points for lymphovascular invasion. Results: LNM rates in the radical surgery group were 1.1%, 5.4%, and 13.3% for the low-(0-1 point), intermediate- (2-3 points), and high-risk (4-8 points), respectively (P-fortrend<0.001). The eCuraU system showed a significantly higher probability of identifying patients with LNM as high-risk than the eCura system (66.7% vs. 22.2%; McNemar P<0.001). In the no additional treatment group, overall survival (93.4%, 87.2%, and 67.6% at 5 years) and cancer-specific survival (99.6%, 98.9%, and 92.9% at 5 years) differed significantly among the low-, intermediate-, and high-risk categories, respectively (both P<0.001). In the high-risk category, surgery outperformed no treatment in terms of overall mortality (hazard ratio, 3.26; P=0.015). Conclusions: The eCuraU system stratified the risk of LNM in patients with UD-EGC after ER. It is strongly recommended that high-risk patients undergo additional surgery.

• Korean Journal of Radiology
• /
• 제21권9호
• /
• pp.1065-1076
• /
• 2020

Objective: To determine the prognostic value of MRI-based tumor regression grading (mrTRG) in rectal cancer compared with pathological tumor regression grading (pTRG), and to assess the effect of diffusion-weighted imaging (DWI) on interobserver agreement for evaluating mrTRG. Materials and Methods: Between 2007 and 2016, we retrospectively enrolled 321 patients (male:female = 208:113; mean age, 60.2 years) with rectal cancer who underwent both pre-chemoradiotherapy (CRT) and post-CRT MRI. Two radiologists independently determined mrTRG using a 5-point grading system with and without DWI in a one-month interval. Two pathologists graded pTRG using a 5-point grading system in consensus. Kaplan-Meier estimation and Cox-proportional hazard models were used for survival analysis. Cohen's kappa analysis was used to determine interobserver agreement. Results: According to mrTRG on MRI with DWI, there were 6 mrTRG 1, 48 mrTRG 2, 109 mrTRG 3, 152 mrTRG 4, and 6 mrTRG 5. By pTRG, there were 7 pTRG 1, 59 pTRG 2, 180 pTRG 3, 73 pTRG 4, and 2 pTRG 5. A 5-year overall survival (OS) was significantly different according to the 5-point grading mrTRG (p = 0.024) and pTRG (p = 0.038). The 5-year disease-free survival (DFS) was significantly different among the five mrTRG groups (p = 0.039), but not among the five pTRG groups (p = 0.072). OS and DFS were significantly different according to post-CRT MR variables: extramural venous invasion after CRT (hazard ratio = 2.259 for OS, hazard ratio = 5.011 for DFS) and extramesorectal lymph node (hazard ratio = 2.610 for DFS). For mrTRG, k value between the two radiologists was 0.309 (fair agreement) without DWI and slightly improved to 0.376 with DWI. Conclusion: mrTRG may predict OS and DFS comparably or even better compared to pTRG. The addition of DWI on T2-weighted MRI may improve interobserver agreement on mrTRG.

• Korean Journal of Radiology
• /
• 제21권12호
• /
• pp.1345-1354
• /
• 2020

Objective: To evaluate radiomics analysis in studies on mild cognitive impairment (MCI) and Alzheimer's disease (AD) using a radiomics quality score (RQS) system to establish a roadmap for further improvement in clinical use. Materials and Methods: PubMed MEDLINE and EMBASE were searched using the terms 'cognitive impairment' or 'Alzheimer' or 'dementia' and 'radiomic' or 'texture' or 'radiogenomic' for articles published until March 2020. From 258 articles, 26 relevant original research articles were selected. Two neuroradiologists assessed the quality of the methodology according to the RQS. Adherence rates for the following six key domains were evaluated: image protocol and reproducibility, feature reduction and validation, biologic/clinical utility, performance index, high level of evidence, and open science. Results: The hippocampus was the most frequently analyzed (46.2%) anatomical structure. Of the 26 studies, 16 (61.5%) used an open source database (14 from Alzheimer's Disease Neuroimaging Initiative and 2 from Open Access Series of Imaging Studies). The mean RQS was 3.6 out of 36 (9.9%), and the basic adherence rate was 27.6%. Only one study (3.8%) performed external validation. The adherence rate was relatively high for reporting the imaging protocol (96.2%), multiple segmentation (76.9%), discrimination statistics (69.2%), and open science and data (65.4%) but low for conducting test-retest analysis (7.7%) and biologic correlation (3.8%). None of the studies stated potential clinical utility, conducted a phantom study, performed cut-off analysis or calibration statistics, was a prospective study, or conducted cost-effectiveness analysis, resulting in a low level of evidence. Conclusion: The quality of radiomics reporting in MCI and AD studies is suboptimal. Validation is necessary using external dataset, and improvements need to be made to feature reproducibility, feature selection, clinical utility, model performance index, and pursuits of a higher level of evidence.

• 대한영상의학회지
• /
• 제81권3호
• /
• pp.654-664
• /
• 2020

목적 경추 전산화단층촬영(cervical spine CT; 이하 C-spine CT)과 일반촬영을 이용하여 환추횡인대골화증(ossification of the transverse ligament of the atlas; 이하 OTLA)과 연관된 영상 소견에 대하여 알아보았다. 대상과 방법 11년간 3975명의 환자에게서 촬영한 5201개의 C-spine CT를 분석하여 OTLA의 유무를 확인하였고, 이를 대조군과 비교하여 그 빈도와 연관된 영상 소견의 통계학적 유의성을 확인하였다. 결과 3975명 중 45명에서 OTLA가 확인되었다(1.1%). 그 빈도는 나이에 따라 증가하는 소견을 보였으며(p < 0.005), 80세 이상인 환자의 12%에서 관찰되었다. 척수 공간(space available for spinal cord; 이하 SAC)은 OTLA 환자군에서 유의하게 작은 것으로 확인되었으며(p < 0.005), 전방환추후두막(anterior atlantooccipital membrane)-Barkow 인대 복합체의 광물질침착(mineralization), 황색인대골화증(ossification of ligamentum flavum), 경추후만증 또한 유의미한 양의 상관관계를 보였다(p < 0.005). 결론 OTLA는 환자의 나이, SAC 협소, 경추후만증, 다른 경추인대의 골화증과 연관되어 퇴행성 척추병증, 전신적인 골 과잉 상태, 혹은 기계적 스트레스나 불안정성에 관련이 있을 것으로 생각된다.

• Korean Journal of Radiology
• /
• 제24권2호
• /
• pp.133-144
• /
• 2023

Objective: Cyclin-dependent kinase inhibitor (CDKN)2A/B homozygous deletion is a key molecular marker of isocitrate dehydrogenase (IDH)-mutant astrocytomas in the 2021 World Health Organization. We aimed to investigate whether qualitative and quantitative MRI parameters can predict CDKN2A/B homozygous deletion status in IDH-mutant astrocytomas. Materials and Methods: Preoperative MRI data of 88 patients (mean age ± standard deviation, 42.0 ± 11.9 years; 40 females and 48 males) with IDH-mutant astrocytomas (76 without and 12 with CDKN2A/B homozygous deletion) from two institutions were included. A qualitative imaging assessment was performed. Mean apparent diffusion coefficient (ADC), 5th percentile of ADC, mean normalized cerebral blood volume (nCBV), and 95th percentile of nCBV were assessed via automatic tumor segmentation. Logistic regression was performed to determine the factors associated with CDKN2A/B homozygous deletion in all 88 patients and a subgroup of 47 patients with histological grades 3 and 4. The discrimination performance of the logistic regression models was evaluated using the area under the receiver operating characteristic curve (AUC). Results: In multivariable analysis of all patients, infiltrative pattern (odds ratio [OR] = 4.25, p = 0.034), maximal diameter (OR = 1.07, p = 0.013), and 95th percentile of nCBV (OR = 1.34, p = 0.049) were independent predictors of CDKN2A/B homozygous deletion. The AUC, accuracy, sensitivity, and specificity of the corresponding model were 0.83 (95% confidence interval [CI], 0.72-0.91), 90.4%, 83.3%, and 75.0%, respectively. On multivariable analysis of the subgroup with histological grades 3 and 4, infiltrative pattern (OR = 10.39, p = 0.012) and 95th percentile of nCBV (OR = 1.24, p = 0.047) were independent predictors of CDKN2A/B homozygous deletion, with an AUC accuracy, sensitivity, and specificity of the corresponding model of 0.76 (95% CI, 0.60-0.88), 87.8%, 80.0%, and 58.1%, respectively. Conclusion: The presence of an infiltrative pattern, larger maximal diameter, and higher 95th percentile of the nCBV may be useful MRI biomarkers for CDKN2A/B homozygous deletion in IDH-mutant astrocytomas.

• Korean Journal of Radiology
• /
• 제23권12호
• /
• pp.1241-1250
• /
• 2022

Objective: To conduct a simulation study to determine whether artificial intelligence (AI)-aided mammography reading can reduce unnecessary recalls while maintaining cancer detection ability in women recalled after mammography screening. Materials and Methods: A retrospective reader study was performed by screening mammographies of 793 women (mean age ± standard deviation, 50 ± 9 years) recalled to obtain supplemental mammographic views regarding screening mammography-detected abnormalities between January 2016 and December 2019 at two screening centers. Initial screening mammography examinations were interpreted by three dedicated breast radiologists sequentially, case by case, with and without AI aid, in a single session. The area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and recall rate for breast cancer diagnosis were obtained and compared between the two reading modes. Results: Fifty-four mammograms with cancer (35 invasive cancers and 19 ductal carcinomas in situ) and 739 mammograms with benign or negative findings were included. The reader-averaged AUC improved after AI aid, from 0.79 (95% confidence interval [CI], 0.74-0.85) to 0.89 (95% CI, 0.85-0.94) (p < 0.001). The reader-averaged specificities before and after AI aid were 41.9% (95% CI, 39.3%-44.5%) and 53.9% (95% CI, 50.9%-56.9%), respectively (p < 0.001). The reader-averaged sensitivity was not statistically different between AI-unaided and AI-aided readings: 89.5% (95% CI, 83.1%-95.9%) vs. 92.6% (95% CI, 86.2%-99.0%) (p = 0.053), although the sensitivities of the least experienced radiologists before and after AI aid were 79.6% (43 of 54 [95% CI, 66.5%-89.4%]) and 90.7% (49 of 54 [95% CI, 79.7%-96.9%]), respectively (p = 0.031). With AI aid, the reader-averaged recall rate decreased by from 60.4% (95% CI, 57.8%-62.9%) to 49.5% (95% CI, 46.5%-52.4%) (p < 0.001). Conclusion: AI-aided reading reduced the number of recalls and improved the diagnostic performance in our simulation using women initially recalled for supplemental mammographic views after mammography screening.

• 문화기술의 융합
• /
• 제10권3호
• /
• pp.421-426
• /
• 2024

계층화분석과정(analytic hierarchy process, AHP)는 쌍대비교를 이용하여, 사람들의 판단기준을 객관적인 수치로 변환해준다. 그런데 너무 많은 쌍대비교를 필요로 한다는 점이 문제이다. 본 연구의 목적은 표준 AHP보다 간편하면서도, 결과물은 유사하게 나오는 새로운 방식의 의사결정지원시스템을 만드는 것이다. 기존 연구들은 복잡한 쌍대비교 과정을 감소시키기 위하여 과정 분리(process separation) 방식을 가장 많이 사용하였다. 본 연구가 채택한 과정 분리 방법은 "분리와 혼합 방식"이다. 즉, 1)판단기준을 평가할 때는 정규 AHP 과정을 사용하고, 2)대안을 비교평가 할 때는 다속성효용모형(multi-attributive utility technique, MAUT)을 적용한다. 이 Hybrid 모형의 과정 감축효과를 이론적으로 도출하기 위하여 정보입력 횟수를 계산하는 산식을 만들었다. 그런 다음, 이 AHP-MAUT Hybrid 모형을 실제 분석 사례인 경기도 주민들이 분당-강남역 간 통근할 때 어떤 교통수단들을 선택하는지 분석하는 사례에 적용하였다. 그 결과 Hybrid 모형을 적용할 때 계산과정이 AHP 모형을 사용했을 때와 비교하여 42.03% 감소하였다. 그리고 Hybrid model을 적용한 주민들의 선택 결과와 표준 AHP를 이용한 주민들의 선택 결과를 서로 비교하였다. 혼동모형에서 도출한 두 모형 간의 선택 일치도(CA)는 82.1%로서, 상당한 정도로 일관성이 있다 할 수 있을 정도였다. 결론적으로 본 연구가 목적하는 바는 AHP보다 간단하고, 편리하면서도 동등하게 효과적인 의사결정지원시스템을 개발하는 것인데, AHP-MAUT Hybrid 모형이 그 목적에 부합하였다. 이런 결과에 힘입어 Hybrid 모형의 적용사례가 증가한다면, 그것이 표준 AHP의 대안 중 하나로 고려될 수 있다는 점이 본 연구의 기여이다.