1.Evaluation of Image Quality and Scan Time Efficiency in Accelerated 3D T1-Weighted Pediatric Brain MRI Using Deep Learning-Based Reconstruction
Hyunsuk YOO ; Hee Eun MOON ; Soojin KIM ; Da Hee KIM ; Young Hun CHOI ; Jeong-Eun CHEON ; Joon Sung LEE ; Seunghyun LEE
Korean Journal of Radiology 2025;26(2):180-192
Objective:
This study evaluated the effect of an accelerated three-dimensional (3D) T1-weighted pediatric brain MRI protocol using a deep learning (DL)-based reconstruction algorithm on scan time and image quality.
Materials and Methods:
This retrospective study included 46 pediatric patients who underwent conventional and accelerated, pre- and post-contrast, 3D T1-weighted brain MRI using a 3T scanner (SIGNA Premier; GE HealthCare) at a single tertiary referral center between March 1, 2023, and April 30, 2023. Conventional scans were reconstructed using intensity Filter A (Conv), whereas accelerated scans were reconstructed using intensity Filter A (Fast_A) and a DL-based algorithm (Fast_DL).Image quality was assessed quantitatively based on the coefficient of variation, relative contrast, apparent signal-to-noise ratio (aSNR), and apparent contrast-to-noise ratio (aCNR) and qualitatively according to radiologists’ ratings of overall image quality, artifacts, noisiness, gray-white matter differentiation, and lesion conspicuity.
Results:
The acquisition times for the pre- and post-contrast scans were 191 and 135 seconds, respectively, for the conventional scan. With the accelerated protocol, these were reduced to 135 and 80 seconds, achieving time reductions of 29.3% and 40.7%, respectively. DL-based reconstruction significantly reduced the coefficient of variation, improved the aSNR, aCNR, and overall image quality, and reduced the number of artifacts compared with the conventional acquisition method (all P < 0.05). However, the lesion conspicuity remained similar between the two protocols.
Conclusion
Utilizing a DL-based reconstruction algorithm in accelerated 3D T1-weighted pediatric brain MRI can significantly shorten the acquisition time, enhance image quality, and reduce artifacts, making it a viable option for pediatric imaging.
2.Prospective Evaluation of Accelerated Brain MRI Using Deep Learning-Based Reconstruction: Simultaneous Application to 2D Spin-Echo and 3D Gradient-Echo Sequences
Kyu Sung CHOI ; Chanrim PARK ; Ji Ye LEE ; Kyung Hoon LEE ; Young Hun JEON ; Inpyeong HWANG ; Roh Eul YOO ; Tae Jin YUN ; Mi Ji LEE ; Keun-Hwa JUNG ; Koung Mi KANG
Korean Journal of Radiology 2025;26(1):54-64
Objective:
To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI.
Materials and Methods:
This study included 150 participants (51 male; mean age 57.3 ± 16.2 years). Each group of 50 participants was scanned using one of three 3T scanners from three different vendors. Conventional and Accel-DL MRI images were obtained from each participant and compared using 2D T1- and T2-weighted and 3D gradient-echo sequences. Accel-DL acquisition was achieved using optimized scan parameters to reduce the scan time, with the acquired images reconstructed using U-Net-based software to transform low-quality, undersampled k-space data into high-quality images. The scan times of Accel-DL and conventional MRI methods were compared. Four neuroradiologists assessed the overall image quality, structural delineation, and artifacts using Likert scale (5- and 3-point scales). Inter-reader agreement was assessed using Fleiss’ kappa coefficient. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and volumetric quantification of regional structures and white matter hyperintensities (WMHs) was performed.
Results:
Accel-DL showed a mean scan time reduction of 39.4% (range, 24.2%–51.3%). Accel-DL improved overall image quality (3.78 ± 0.71 vs. 3.36 ± 0.61, P < 0.001), structure delineation (2.47 ± 0.61 vs. 2.35 ± 0.62, P < 0.001), and artifacts (3.73 ± 0.72 vs. 3.71 ± 0.69, P = 0.016). Inter-reader agreement was fair to substantial (κ = 0.34–0.50). SNR and CNR increased in Accel-DL (82.0 ± 23.1 vs. 31.4 ± 10.8, P = 0.02; 12.4 ± 4.1 vs. 4.4 ± 11.2, P = 0.02). Bland-Altman plots revealed no significant differences in the volumetric measurements of 98.2% of the relevant regions, except in the deep gray matter, including the thalamus. Five of the six lesion categories showed no significant differences in WMH segmentation, except for leukocortical lesions (r = 0.64 ± 0.29).
Conclusion
Accel-DL substantially reduced the scan time and improved the quality of brain MRI in both spin-echo and gradientecho sequences without compromising volumetry, including lesion quantification.
3.Prevalence and characteristics of impacted teeth in Korean orthodontic patients at ten university dental hospitals
Youn-Kyung CHOI ; Sung-Hun KIM ; Yong-Il KIM ; Seong-Sik KIM ; Soo-Byung PARK ; Dong-Soon CHOI ; Ho-Jin KIM ; Kyung-A KIM ; Mo-Hyeon LEE ; Sung-Hwan CHOI ; Sung-Kwon CHOI ; Kyungmin Clara LEE ; Young-Mi JEON ; Sewoong OH ; Seorin JEONG
The Korean Journal of Orthodontics 2025;55(3):234-241
Objective:
This study aimed to investigate the prevalence and characteristics of impacted teeth (ITs) in orthodontic patients at university dental hospitals in Korea.
Methods:
This study included 14,774 patients who visited the Department of Orthodontics at 10 university dental hospitals in Korea between 2020 and 2022 and underwent orthodontic diagnosis. The prevalence and characteristics of ITs were investigated using orthodontic diagnostic records, radiographs, and diagnostic casts.
Results:
The prevalence of ITs, excluding third molar impaction, in Korean orthodontic patients was 13.6% (n = 2,014).The prevalence of ITs in pediatric orthodontic patients was 24.5% (n = 1,614).Of these patients, 68.2% had one IT, 27.5% had two ITs, 24.3% had bilateral IT, and 75.7% had unilateral IT. The most frequent IT was the maxillary canine (50.1%), followed by the mandibular second molar (11.7%), and maxillary second premolar (9.6%). An abnormal eruption path (46.5%) was the most frequent etiology. Orthodontic traction after surgical exposure (70.6%) was the most frequent treatment option. Among the patients with ITs, 29.8% had other dental anomalies, such as tooth agenesis (8.7%), microdontia (8.0%), and supernumerary teeth (5.1%). Furthermore, 50.8% had complications such as cystic lesions (18.3%), transposition (17.7%), and root resorption (14.8%).Among the patients with maxillary canine impaction, 62.2% had labial maxillary canine impaction and 21.1% had palatal maxillary canine impaction.
Conclusions
The prevalence of ITs in Korean orthodontic patients at university dental hospitals was high, particularly in pediatric orthodontic patients.
4.Effects of clear aligner edentulous space design on distal canine movement: An iterative finite element analysis in cases involving extraction
Seung Eun BAEK ; Kiyean KIM ; Youn-Kyung CHOI ; Sung-Hun KIM ; Seong-Sik KIM ; Ki Beom KIM ; Yong-Il KIM
The Korean Journal of Orthodontics 2025;55(3):193-201
Objective:
Using finite element method (FEM) analysis of a clear aligner (CA), this study aimed to investigate the effects of varying the edentulous space on canine distal bodily movement during space closure following maxillary first premolar extraction.
Methods:
FEM analysis was used to simulate distal canine bodily movement following maxillary first premolar extraction using CAs. Four CA designs for edentulous spaces were compared: no-pontic, full-pontic, halfpontic, and beam. Three-dimensional models of the tooth components and CA were created. The target was set at a 0.25-mm distal canine movement. Long-term tooth movement was simulated using an iterative calculation method.
Results:
All the groups initially showed crown displacement, distal tipping, and distal rotation.Over time, the movement patterns differed in relation to the design. The no-pontic design exhibited the greatest displacement and tipping. The beam design exhibited the largest initial displacement but showed the lowest displacement and tipping thereafter. Full- and half-pontic designs yielded intermediate results. Significant force reduction was observed immediately after CA application, and was followed by a gradual decrease. The mean tooth-movement achievement rate was approximately 76.7%.
Conclusions
The edentulous space design of the CA substantially affected tooth-movement behavior. An iterative simulation is necessary to evaluate longterm tooth-movement patterns. The beam design demonstrated optimal suitability for bodily movement with minimal tipping. For optimal results, additional setup or overcorrection may be necessary.
5.Force and moment analysis of clear aligners: Impact of material properties and design on premolar rotation
Dong-Woo KIM ; Hyun-Jun LEE ; Ki Beom KIM ; Sung-Hun KIM ; Seong-Sik KIM ; Soo-Byung PARK ; Youn-Kyung CHOI ; Yong-Il KIM
The Korean Journal of Orthodontics 2025;55(3):212-223
Objective:
To quantitatively analyze and compare the forces and moments generated by thermoformed polyethylene terephthalate glycol (PETG) and direct-printed TC-85 clear aligners (CAs), with various margin designs, during premolar rotation.
Methods:
In total, 132 CAs were fabricated and divided into four groups (n = 33 per group). Group C consisted of thermoformed PETG aligners with a 2 mm gingival margin. Group E comprised direct-printed TC-85 aligners with equi-gingival margin, whereas Group G utilized direct-printed TC-85 aligners with 2 mm gingival margins.Finally, Group T featured direct-printed TC-85 aligners with an additional 1 mm thickness at the mesial embrasure. The forces and moments were measured using a 6-axis force/moment transducer at 2°, 3°, and 4° of rotation. All measurements were conducted at 37°C to simulate intraoral conditions. Forces were measured in the buccolingual, anteroposterior, and vertical directions, while moments were measured in the mesiodistal, buccolingual, and rotational planes.
Results:
The PETG aligners (Group C) showed significantly increased buccal and posterior force across the rotation angles (P < 0.05), whereas the intrusive force remained consistent. In contrast, the TC-85 aligners maintained consistent forces across all rotation angles.Direct-printed aligners demonstrated significantly lower intrusive forces than PETG aligners (P < 0.001). Group T exhibited reduced unwanted forces while maintaining effective rotational moments. Furthermore, all direct-printed aligners showed more predictable force delivery patterns than thermoformed aligners.
Conclusions
Direct-printed TC-85 aligners demonstrated superior force consistency and reduced unwanted side effects compared with traditional PETG aligners. Although marginal design modifications did not significantly improve rotational efficiency, they effectively reduced unwanted intrusive forces.
6.Perceptions of treatment, accompanying symptoms, and other problems in patients with chronic pain: a multicenter cross-sectional study in Korea
Jieun BAE ; Yun Hee LIM ; Sung Jun HONG ; Jae Hun JEONG ; Hey Ran CHOI ; Sun Kyung PARK ; Jung Eun KIM ; Jae Hun KIM
The Korean Journal of Pain 2025;38(1):69-78
Background:
Chronic pain significantly affects daily activities, mental health, and the interpersonal relationships of patients. Consequently, physicians use various treatments to manage pain. This study investigated the perceptions of treatment, accompanying symptoms, and other problems in patients with chronic pain.
Methods:
The authors enrolled patients with chronic pain from 19 university hospitals in South Korea. Data was collected on age, gender, diagnosis, disease duration, severity of pain, perception of pain treatment, and accompanying symptoms or problems using an anonymous survey comprising 19 questions.
Results:
In total, 833 patients with chronic pain completed the survey, and 257 (31.0%) and 537 (64.5%) patientsexpressed concerns about the potential adverse effects of medication and opioid addiction, respectively. Personalitychanges such as irritability or anger were the most frequent accompanying symptoms in 507 (63.8%) patients, followed by depression and sleep disturbance in 462 (58.1%) and 450 (54.5%) patients, respectively. Depression (P = 0.001) and anxiety (P = 0.029) were more common among women, whereas divorce (P = 0.016), family conflict (P < 0.001), unemployment (P < 0.001), suicide attempts (P < 0.001), and restrictions on economic activity (P < 0.001) were more common among men. The frequency of accompanying symptoms, except for suicidal ideation,was higher in the younger patients aged ≤ 40 years than in the older patients aged > 40 years.
Conclusions
Many patients with chronic pain had concerns about adverse effects or medication tolerance and experienced anxiety, depression, or sleep disturbances. The prevalence of accompanying problems varies according to age and gender.
7.Pericapsular Nerve Group Block with Periarticular Injection for Pain Management after Total Hip Arthroplasty: A Randomized Controlled Trial
Hun Sik CHO ; Bo Ra LEE ; Hyuck Min KWON ; Jun Young PARK ; Hyeong Won HAM ; Woo-Suk LEE ; Kwan Kyu PARK ; Tae Sung LEE ; Yong Seon CHOI
Yonsei Medical Journal 2025;66(4):233-239
Purpose:
The purpose of this study was to compare the effectiveness of pericapsular nerve group (PENG) block with periarticular multimodal drug injection (PMDI) on postoperative pain management and surgical outcomes in patients who underwent total hip arthroplasty (THA). We hypothesized that PENG block with PMDI would exhibit superior effects on postoperative pain control after THA compared to PMDI alone.
Materials and Methods:
From April 2022 to February 2023, 58 patients who underwent THA were randomly assigned into two groups: PENG block with PMDI group (n=29) and PMDI-only group (n=29). Primary outcomes were postoperative numeric rating scale (NRS) at rest and during activity at 6, 24, and 48 hours postoperatively. Secondary outcomes were postoperative complications (nausea and vomiting), Richards-Campbell Sleep Questionnaire (RCSQ) score, length of hospital stay, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, Harris Hip Score (HHS), and total morphine usage after surgery.
Results:
There was no significant difference in postoperative pain for either resting NRS or active NRS. Postoperative nausea and vomiting, RCSQ score, length of hospital stay, WOMAC index, HHS, and total morphine usage exhibited no significant differences between the two groups.
Conclusion
Both groups showed no significant differences in postoperative pain and clinical outcomes, indicating that the addition of PENG block to PMDI does not improve pain management after applying the posterolateral approach of THA. PMDI alone during THA would be an efficient, fast, and safe method for managing postoperative pain. This article was registered with ClinicalTrials.gov (Gov ID: NCT05320913).
8.Early Administration of Nelonemdaz May Improve the Stroke Outcomes in Patients With Acute Stroke
Jin Soo LEE ; Ji Sung LEE ; Seong Hwan AHN ; Hyun Goo KANG ; Tae-Jin SONG ; Dong-Ick SHIN ; Hee-Joon BAE ; Chang Hun KIM ; Sung Hyuk HEO ; Jae-Kwan CHA ; Yeong Bae LEE ; Eung Gyu KIM ; Man Seok PARK ; Hee-Kwon PARK ; Jinkwon KIM ; Sungwook YU ; Heejung MO ; Sung Il SOHN ; Jee Hyun KWON ; Jae Guk KIM ; Young Seo KIM ; Jay Chol CHOI ; Yang-Ha HWANG ; Keun Hwa JUNG ; Soo-Kyoung KIM ; Woo Keun SEO ; Jung Hwa SEO ; Joonsang YOO ; Jun Young CHANG ; Mooseok PARK ; Kyu Sun YUM ; Chun San AN ; Byoung Joo GWAG ; Dennis W. CHOI ; Ji Man HONG ; Sun U. KWON ;
Journal of Stroke 2025;27(2):279-283
9.Comparison between Suture-Button Technique with Syndesmotic Repair and Screw Fixation Technique for Complete Ankle Syndesmotic Injury: Biomechanical Cadaveric Study
Hong Seop LEE ; Sung Hwan KIM ; Ki Won YOUNG ; Woo Jong KIM ; Dong-Il CHEON ; Sung Hun WON ; Sang Heon LEE ; Seung Jin CHOI ; Young Koo LEE
Clinics in Orthopedic Surgery 2025;17(2):324-330
Background:
The tibiofibular syndesmosis is essential for preserving the stability of the ankle. Acute syndesmotic injuries with evident or latent instability usually warrant surgical interventions. This cadaveric study examines and compares biomechanical characteristics between the following treatments for syndesmosis injuries: suture-button fixation plus syndesmotic repair and screw fixation.
Methods:
The lower extremities of 10 cadavers disarticulated at the knee joints were used, yielding 20 feet. Ten feet underwent surgery using the suture-button fixation with syndesmotic repair, while the remaining 10 feet underwent surgery using screw fixation. Before surgical treatment of syndesmosis injuries, each cadaveric lower limb underwent preliminary physiological cyclic loading, which was followed by a series of postfixation cyclic loading tests after the surgical procedure.
Results:
Our principal finding is that suture-button fixation with syndesmotic repair provided torsional strength comparable to that of screw fixation. The mean failure torque did not differ between the 2 groups, but the rotational stiffness was significantly lower in the suture-button fixation/augmentation group.
Conclusions
Suture-button fixation/augmentation facilitates flexible (physiological) syndesmosis movement and may be a useful alternative treatment for ankle syndesmosis injury.
10.Hepatoprotective Effects of Resveratrol on Acetaminophen-Induced Acute Liver Injury and Its Implications for Tofacitinib Disposition in Rats
Hyeon Gyeom CHOI ; So Yeon PARK ; Sung Hun BAE ; Sun-Young CHANG ; So Hee KIM
Biomolecules & Therapeutics 2025;33(3):501-509
Tofacitinib, which is used to treat rheumatoid arthritis (RA), is primarily metabolized by the hepatic cytochrome P450 (CYP) enzymes, CYP3A1/2 and CYP2C11. Acetaminophen (APAP), which is frequently used for pain relief in patients with RA, can induce acute liver injury (ALI) when taken in excess, profoundly affecting drug metabolism. Resveratrol (RVT) is a polyphenolic compound with hepatoprotective properties. This study investigated the protective effects of RVT against APAP-induced ALI in rats, and explored its influence on the pharmacokinetics of tofacitinib. In ALI rats, both intravenous and oral administration of tofacitinib resulted in a significant (207% and 181%) increase in the area under the plasma concentration-time curve (AUC), primarily driven by a substantial reduction (66.1%) in non-renal clearance (CLNR) compared to that in control (CON) rats. Notably, RVT administration in ALI rats provided effective liver protection, partially restoring liver function, as evidenced by normalized glutamate oxaloacetate transaminase levels and the pharmacokinetic parameters, AUC and CLNR, closer to those observed in untreated CON rats (117% and 81.9%, respectively). These findings highlight the importance of considering the potential interactions between RVT or polyphenol-rich natural products and medications in patients with ALI in clinical practice.

Result Analysis
Print
Save
E-mail