• Korean Journal of Radiology
• /
• v.24 no.5
• /
• pp.395-405
• /
• 2023

Objective: This study aimed to develop and validate models using radiomics features on a native T1 map from cardiac magnetic resonance (CMR) to predict left ventricular reverse remodeling (LVRR) in patients with nonischemic dilated cardiomyopathy (NIDCM). Materials and Methods: Data from 274 patients with NIDCM who underwent CMR imaging with T1 mapping at Severance Hospital between April 2012 and December 2018 were retrospectively reviewed. Radiomic features were extracted from the native T1 maps. LVRR was determined using echocardiography performed ≥ 180 days after the CMR. The radiomics score was generated using the least absolute shrinkage and selection operator logistic regression models. Clinical, clinical + late gadolinium enhancement (LGE), clinical + radiomics, and clinical + LGE + radiomics models were built using a logistic regression method to predict LVRR. For internal validation of the result, bootstrap validation with 1000 resampling iterations was performed, and the optimism-corrected area under the receiver operating characteristic curve (AUC) with 95% confidence interval (CI) was computed. Model performance was compared using AUC with the DeLong test and bootstrap. Results: Among 274 patients, 123 (44.9%) were classified as LVRR-positive and 151 (55.1%) as LVRR-negative. The optimism-corrected AUC of the radiomics model in internal validation with bootstrapping was 0.753 (95% CI, 0.698-0.813). The clinical + radiomics model revealed a higher optimism-corrected AUC than that of the clinical + LGE model (0.794 vs. 0.716; difference, 0.078 [99% CI, 0.003-0.151]). The clinical + LGE + radiomics model significantly improved the prediction of LVRR compared with the clinical + LGE model (optimism-corrected AUC of 0.811 vs. 0.716; difference, 0.095 [99% CI, 0.022-0.139]). Conclusion: The radiomic characteristics extracted from a non-enhanced T1 map may improve the prediction of LVRR and offer added value over traditional LGE in patients with NIDCM. Additional external validation research is required.

• Korean Journal of Radiology
• /
• v.23 no.9
• /
• pp.866-877
• /
• 2022

Objective: The optimal imaging approach for evaluating pathological nipple discharge remains unclear. We investigated the value of adding ductography to ultrasound (US) for evaluating pathologic nipple discharge in patients with negative mammography findings. Materials and Methods: From July 2003 to December 2018, 101 women (mean age, 46.3 ± 12.2 years; range, 23-75 years) with pathologic nipple discharge were evaluated using pre-ductography (initial) US, ductography, and post-ductography US. The imaging findings were reviewed retrospectively. The standard reference was surgery (70 patients) or > 2 years of follow-up with US (31 patients). The diagnostic performances of initial US, ductography, and post-ductography US for detecting malignancy were compared using the McNemar's test or a generalized estimating equation. Results: In total, 47 papillomas, 30 other benign lesions, seven high-risk lesions, and 17 malignant lesions were identified as underlying causes of pathologic nipple discharge. Only eight of the 17 malignancies were detected on the initial US, while the remaining nine malignancies were detected by ductography. Among the nine malignancies detected by ductography, eight were detected on post-ductography US and could be localized for US-guided intervention. The sensitivities of ductography (94.1% [16/17]) and post-ductography US (94.1% [16/17]) were significantly higher than those of initial US (47.1% [8/17]; p = 0.027 and 0.013, respectively). The negative predictive value of post-ductography US (96.9% [31/32]) was significantly higher than that of the initial US (83.3% [45/54]; p = 0.006). Specificity was significantly higher for initial US than for ductography and post-ductography US (p = 0.001 for all). Conclusion: The combined use of ductography and US has a high sensitivity for detecting malignancy in patients with pathologic nipple discharge and negative mammography. Ductography findings enable lesion localization on second-look post-ductography US, thus facilitating the selection of optimal treatment plans.

• Korean Journal of Radiology
• /
• v.23 no.5
• /
• pp.548-554
• /
• 2022

Objective: To evaluate the safety and feasibility of prostatic artery embolization (PAE) via transradial access (TRA) compared with transfemoral access (TFA). Materials and Methods: This retrospective study included 53 consecutive men with lower urinary tract symptoms (LUTS) who underwent PAE between September 2018 and September 2021. Thirty-one patients (mean age ± standard deviation: 70.6 ± 8.4 years) were treated with TFA, including 14 patients treated before adopting TRA. Since December 2019, TRA has also been attempted with the procedure's selection criteria of patent carpal circulation and a height ≤ 172 cm, with 22 patients treated via TRA (69.1 ± 9.6 years). Parameters of technical success (defined as successful bilateral embolization), clinical success (defined as LUTS improvement), procedural time, radiation dose, and adverse events were compared between the two groups using the Fisher's exact test, independent sample t test, Wilcoxon signed-rank test, or Mann-Whitney test. Results: All patients received at least one-side PAE. Technical success of PAE was achieved in most patients (TRA, 21/22; TFA, 30/31; p > 0.999). No technical problem-related conversion from TRA to TFA occurred. The clinical success rate was 85% (11/13) in patients with TRA, and 89% (16/18) in patients with TFA for follow-up > 2 weeks post-PAE (median, 3 months) (p > 0.999). The median procedure time was similar in both groups (TRA, 81 minutes vs. TFA, 94 minutes; p = 0.570). No significant dose differences were found between the TRA and TFA groups in the dose-area product (median Gycm², 95 [range, 44-255] for TRA and 84 [34-255] for TFA; p = 0.678) or cumulative air kerma (median mGy, 609 [236-1584] for TRA and 634 [217-1594] for TFA; p = 0.551). No major adverse events occurred in either of the groups. Conclusion: PAE via TRA is a safe and feasible method comparable to conventional TFA. It can be safely implemented by selecting patients with patent carpal circulation and adequate height.

• Korean Journal of Radiology
• /
• v.24 no.9
• /
• pp.827-837
• /
• 2023

Objective: To investigate the predictive value of radiomics features based on cardiac magnetic resonance (CMR) cine images for left ventricular adverse remodeling (LVAR) after acute ST-segment elevation myocardial infarction (STEMI). Materials and Methods: We conducted a retrospective, single-center, cohort study involving 244 patients (random-split into 170 and 74 for training and testing, respectively) having an acute STEMI (88.5% males, 57.0 ± 10.3 years of age) who underwent CMR examination at one week and six months after percutaneous coronary intervention. LVAR was defined as a 20% increase in left ventricular end-diastolic volume 6 months after acute STEMI. Radiomics features were extracted from the oneweek CMR cine images using the least absolute shrinkage and selection operator regression (LASSO) analysis. The predictive performance of the selected features was evaluated using receiver operating characteristic curve analysis and the area under the curve (AUC). Results: Nine radiomics features with non-zero coefficients were included in the LASSO regression of the radiomics score (RAD score). Infarct size (odds ratio [OR]: 1.04 (1.00-1.07); P = 0.031) and RAD score (OR: 3.43 (2.34-5.28); P < 0.001) were independent predictors of LVAR. The RAD score predicted LVAR, with an AUC (95% confidence interval [CI]) of 0.82 (0.75-0.89) in the training set and 0.75 (0.62-0.89) in the testing set. Combining the RAD score with infarct size yielded favorable performance in predicting LVAR, with an AUC of 0.84 (0.72-0.95). Moreover, the addition of the RAD score to the left ventricular ejection fraction (LVEF) significantly increased the AUC from 0.68 (0.52-0.84) to 0.82 (0.70-0.93) (P = 0.018), which was also comparable to the prediction provided by the combined microvascular obstruction, infarct size, and LVEF with an AUC of 0.79 (0.65-0.94) (P = 0.727). Conclusion: Radiomics analysis using non-contrast cine CMR can predict LVAR after STEMI independently and incrementally to LVEF and may provide an alternative to traditional CMR parameters.

• Korean Journal of Radiology
• /
• v.23 no.11
• /
• pp.1078-1088
• /
• 2022

Objective: To develop and validate a model using radiomics features from apparent diffusion coefficient (ADC) map to diagnose local tumor recurrence in head and neck squamous cell carcinoma (HNSCC). Materials and Methods: This retrospective study included 285 patients (mean age ± standard deviation, 62 ± 12 years; 220 male, 77.2%), including 215 for training (n = 161) and internal validation (n = 54) and 70 others for external validation, with newly developed contrast-enhancing lesions at the primary cancer site on the surveillance MRI following definitive treatment of HNSCC between January 2014 and October 2019. Of the 215 and 70 patients, 127 and 34, respectively, had local tumor recurrence. Radiomics models using radiomics scores were created separately for T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and ADC maps using non-zero coefficients from the least absolute shrinkage and selection operator in the training set. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of each radiomics score and known clinical parameter (age, sex, and clinical stage) in the internal and external validation sets. Results: Five radiomics features from T2WI, six from CE-T1WI, and nine from ADC maps were selected and used to develop the respective radiomics models. The area under ROC curve (AUROC) of ADC radiomics score was 0.76 (95% confidence interval [CI], 0.62-0.89) and 0.77 (95% CI, 0.65-0.88) in the internal and external validation sets, respectively. These were significantly higher than the AUROC values of T2WI (0.53 [95% CI, 0.40-0.67], p = 0.006), CE-T1WI (0.53 [95% CI, 0.40-0.67], p = 0.012), and clinical parameters (0.53 [95% CI, 0.39-0.67], p = 0.021) in the external validation set. Conclusion: The radiomics model using ADC maps exhibited higher diagnostic performance than those of the radiomics models using T2WI or CE-T1WI and clinical parameters in the diagnosis of local tumor recurrence in HNSCC following definitive treatment.

• Korean Journal of Radiology
• /
• v.20 no.5
• /
• pp.791-800
• /
• 2019

Objective: To compare various models of diffusion-weighted imaging including monoexponential apparent diffusion coefficient (ADC), biexponential (fast diffusion coefficient [D_f], slow diffusion coefficient [D_s], and fraction of fast diffusion), stretched-exponential (distributed diffusion coefficient and anomalous exponent term [α]), and kurtosis (mean diffusivity and mean kurtosis [MK]) models in the differentiation of renal solid masses. Materials and Methods: A total of 81 patients (56 men and 25 women; mean age, 57 years; age range, 30-69 years) with 18 benign and 63 malignant lesions were imaged using 3T diffusion-weighted MRI. Diffusion model selection was investigated in each lesion using the Akaike information criteria. Mann-Whitney U test and receiver operating characteristic (ROC) analysis were used for statistical evaluations. Results: Goodness-of-fit analysis showed that the stretched-exponential model had the highest voxel percentages in benign and malignant lesions (90.7% and 51.4%, respectively). ADC, D_s, and MK showed significant differences between benign and malignant lesions (p < 0.05) and between low- and high-grade clear cell renal cell carcinoma (ccRCC) (p < 0.05). α was significantly lower in the benign group than in the malignant group (p < 0.05). All diffusion measures showed significant differences between ccRCC and non-ccRCC (p < 0.05) except D_f and α (p = 0.143 and 0.112, respectively). α showed the highest diagnostic accuracy in differentiating benign and malignant lesions with an area under the ROC curve of 0.923, but none of the parameters from these advanced models revealed significantly better performance over ADC in discriminating subtypes or grades of renal cell carcinoma (RCC) (p > 0.05). Conclusion: Compared with conventional diffusion parameters, α may provide additional information for differentiating benign and malignant renal masses, while ADC remains the most valuable parameter for differentiation of RCC subtypes and for ccRCC grading.

• The Journal of Korean Academy of Sensory Integration
• /
• v.21 no.3
• /
• pp.65-78
• /
• 2023

Objective : In this study, we aimed to investigate the effectiveness of family-centered intervention conducted with caregivers of children with autism spectrum disorder (ASD) in South Korea through a systematic literature review. Methods : Previous studies published from 2011 to 2021 were searched through RISS, KISS, and DBpia. The search terms applied included "autism spectrum" OR "general developmental disorder" OR "high-functioning autism" OR "Asperger's" AND "parent education" OR "family-centered intervention" OR "parent coaching" OR "parent training" OR "family participation." A total of 11 experimental studies were chosen based on the selection criteria. Results : According to the findings on the general characteristics of the study participants, intervention strategies, and effects of the intervention, it was observed that the majority of children with ASD who participated in the study were preschool-aged, and the majority of participating caregivers were mothers. The effects of family-centered interventions were evident in both children and parents. In children, the most significant effects were observed in interaction and communication skills. In parents, a reduction in parenting stress and an improvement in parenting efficacy were observed. The intervention strategies employed in the study varied, with sensory integration intervention, responsive communication, and interaction-centered intervention being the most commonly used, followed by developmental-centered intervention, positive behavior support (PBS), and parent-mediated intervention based on pivotal response treatment (PRT). Conclusion : The results of this study are significant in that they confirm that family-centered intervention is effective not only in improving the functioning of children with autism spectrum disorder, but also in reducing parenting stress and enhancing parenting efficacy, and provide evidence for clinical use.

• Korean Journal of Radiology
• /
• v.21 no.6
• /
• pp.764-772
• /
• 2020

Objective: Laser ablation is a therapeutic modality used to reduce the volume of large benign thyroid nodules. Unsatisfactory reduction and regrowth are observed in some treated nodules. The aim of the study was to evaluate the long-term outcomes of laser treatment for solid nodules during a 5-year follow-up period, the regrowth rate, and the predictive risk factors of nodule regrowth. Materials and Methods: We retrospectively evaluated patients with benign, solid, cold thyroid nodules who underwent laser ablation and were followed-up for 5 years. According to the selection criteria, 104 patients were included (median baseline nodule volume, 12.5 mL [25.0-75.0%, 8-18 mL]; median energy delivered, 481.5 J/mL [25.0-75.0%, 370-620 J/mL]). Nodule volume, thyroid function test results, and ultrasound were evaluated at baseline and then annually after the procedure. Results: Of 104 patients, 31 patients (29.8%) had a 12-month volume reduction ratio (VRR) < 50.0% and 39 (37.5%) experienced nodule regrowth. Of these 39 patients, 17 (43.6%) underwent surgery and 14 (35.9%) underwent a second laser treatment. The rate of nodule regrowth was inversely related to the 12-month VRR, i.e., the lower the 12-month VRR, the higher the risk of regrowth (p < 0.001). The mean time for nodule regrowth was 33.5 ± 16.6 months. The 12-month VRR was directly related to time to regrowth, i.e., the lower the 12-month VRR, the shorter the time to regrowth (p < 0.001; R² = 0.3516). Non-spongiform composition increased the risk of regrowth with an odds ratio of 4.3 (95% confidence interval [CI] 1.8-10.2; p < 0.001); 12-month VRR < 50.0% increased the risk of regrowth with an odds ratio of 11.7 (95% CI 4.2-32.2; p < 0.001). Conclusion: The VRR of thyroid nodules subjected to similar amounts of laser energy varies widely and depends on the nodule composition; non-spongiform nodules are reduced to a lesser extent and regrow more frequently than spongiform nodules. A 12-month VRR < 50.0% is a predictive risk factor for regrowth and correlates with the time to regrowth.

• Korean Journal of Radiology
• /
• v.21 no.12
• /
• 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.

• Therapeutic Science for Rehabilitation
• /
• v.13 no.2
• /
• pp.27-40
• /
• 2024

Objective : This study aimed to conduct a systematic review of the assessment tools used to assess the housing environment of older adults. Methods : Data were collected from January 2015 to August 31st, 2023, by searching databases including the Cochrane Library, PubMed, and ProQuest. From the 267 articles, nine assessment tools were selected for analysis based on their original instruments. These tools were categorized and systematically organized for analysis based on their frequency of use, assessment purposes, sub-domains, scales, and other relevant criteria. Results : Among the nine tools, HOME FAST and IPAQ-E were the most frequently used (20% each). The objectives of these tools are to assess friendliness, physical barriers, fall prevention, dementia-friendly environments, physical activity, and accessibility. The measurement scope encompassed various factors, such as outdoor spaces, buildings, transportation, housing, and community support. Conclusion : When considering the suitability of housing for the older adults population, providing foundational data for the rational selection of evaluation tools with logical validity is important. This includes factors such as the objectives and measurement scopes of housing environment assessment tools.