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.
4.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.
5.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.
6.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.
7.Diagnosis and Management of Peyronie’s Disease: A Clinical Consensus Statement and Recommendations from the Korean Society for Sexual Medicine and Andrology
Dong Soo KIM ; Hee Jo YANG ; Hyun Cheol JEONG ; Ki Hyuck MOON ; Dong Sup LEE ; Seung Hun SONG ; Won Ki LEE ;
The World Journal of Men's Health 2025;43(1):50-59
Peyronie’s disease is an acquired condition characterized by penile deformities caused by fibrosis of the penile tunica albuginea, leading to symptoms such as penile pain, erectile dysfunction, and other associated issues. Despite extensive research, the pathophysiology of this condition remains poorly understood, and standardized diagnostic and treatment protocols are lacking. While clinical guidelines from several professional societies exist, they do not consistently account for factors such as patient ethnicity, geography, and socioeconomic status. Thus, the Korean Society for Sexual Medicine and Andrology (KSSMA) aimed to develop recommendations tailored to clinical practice in Korea. These recommendations summarize the latest evidence, including clinical practice guidelines from various international professional societies, and represent the consensus opinion of an expert group within the KSSMA. They encompass all aspects of Peyronie’s disease, including the definition, diagnosis, non-surgical interventions, and surgical treatment options.
8.Comparison of Higher-order Aberrations Outcomes between Sutured Scleral Fixation and Modified Yamane Sutureless Scleral Fixation
Dong Jin HAN ; Myung Jun SEONG ; Jong Min LEE ; Jong Hyun LEE ; Do Hyung LEE ; Min Kyung SONG ; Hun JIn CHOI
Journal of the Korean Ophthalmological Society 2025;66(2):86-93
Purpose:
We investigated the changes in ocular higher-order aberrations (HOAs) between sutured scleral fixation and modified Yamane sutureless scleral fixation.
Methods:
We retrospectively reviewed 20 patients (20 eyes) who underwent sutured scleral fixation and 22 patients (22 eyes) who underwent modified Yamane sutureless scleral fixation. The best corrected visual acuity (BCVA) and HOAs were measured preoperatively, and at 3 months postoperatively, and the two groups were compared.
Results:
BCVA was significantly improved in both sutured scleral fixation and modified Yamane sutureless scleral fixation (p = 0.038, 0.015, respectively). The internal optic HOAs decreased significantly after scleral fixation both in both groups (p = 0.012, 0.033, respectively). Postoperative internal optic HOAs were significantly higher in modified Yamane sutureless scleral fixation group than in sutured scleral fixation group. (p = 0.034) Postoperative third-order aberrations, coma-like aberrations were significantly higher in modified Yamane sutureless scleral fixation group than in sutured scleral fixation group. (p = 0.032, 0.038, respectively)
Conclusions
Sutured scleral fixation showed more effectively decreased internal optics HOAs. IOL tilt and decentrations correlated with internal HOAs and thus should be avoided particularly in modified Yamane sutureless scleral fixation.
9.Erratum: Korean Gastric Cancer Association-Led Nationwide Survey on Surgically Treated Gastric Cancers in 2023
Dong Jin KIM ; Jeong Ho SONG ; Ji-Hyeon PARK ; Sojung KIM ; Sin Hye PARK ; Cheol Min SHIN ; Yoonjin KWAK ; Kyunghye BANG ; Chung-sik GONG ; Sung Eun OH ; Yoo Min KIM ; Young Suk PARK ; Jeesun KIM ; Ji Eun JUNG ; Mi Ran JUNG ; Bang Wool EOM ; Ki Bum PARK ; Jae Hun CHUNG ; Sang-Il LEE ; Young-Gil SON ; Dae Hoon KIM ; Sang Hyuk SEO ; Sejin LEE ; Won Jun SEO ; Dong Jin PARK ; Yoonhong KIM ; Jin-Jo KIM ; Ki Bum PARK ; In CHO ; Hye Seong AHN ; Sung Jin OH ; Ju-Hee LEE ; Hayemin LEE ; Seong Chan GONG ; Changin CHOI ; Ji-Ho PARK ; Eun Young KIM ; Chang Min LEE ; Jong Hyuk YUN ; Seung Jong OH ; Eunju LEE ; Seong-A JEONG ; Jung-Min BAE ; Jae-Seok MIN ; Hyun-dong CHAE ; Sung Gon KIM ; Daegeun PARK ; Dong Baek KANG ; Hogoon KIM ; Seung Soo LEE ; Sung Il CHOI ; Seong Ho HWANG ; Su-Mi KIM ; Moon Soo LEE ; Sang Hyun KIM ; Sang-Ho JEONG ; Yusung YANG ; Yonghae BAIK ; Sang Soo EOM ; Inho JEONG ; Yoon Ju JUNG ; Jong-Min PARK ; Jin Won LEE ; Jungjai PARK ; Ki Han KIM ; Kyung-Goo LEE ; Jeongyeon LEE ; Seongil OH ; Ji Hun PARK ; Jong Won KIM ;
Journal of Gastric Cancer 2025;25(2):400-402
10.Korean Gastric Cancer AssociationLed Nationwide Survey on Surgically Treated Gastric Cancers in 2023
Dong Jin KIM ; Jeong Ho SONG ; Ji-Hyeon PARK ; Sojung KIM ; Sin Hye PARK ; Cheol Min SHIN ; Yoonjin KWAK ; Kyunghye BANG ; Chung-sik GONG ; Sung Eun OH ; Yoo Min KIM ; Young Suk PARK ; Jeesun KIM ; Ji Eun JUNG ; Mi Ran JUNG ; Bang Wool EOM ; Ki Bum PARK ; Jae Hun CHUNG ; Sang-Il LEE ; Young-Gil SON ; Dae Hoon KIM ; Sang Hyuk SEO ; Sejin LEE ; Won Jun SEO ; Dong Jin PARK ; Yoonhong KIM ; Jin-Jo KIM ; Ki Bum PARK ; In CHO ; Hye Seong AHN ; Sung Jin OH ; Ju-Hee LEE ; Hayemin LEE ; Seong Chan GONG ; Changin CHOI ; Ji-Ho PARK ; Eun Young KIM ; Chang Min LEE ; Jong Hyuk YUN ; Seung Jong OH ; Eunju LEE ; Seong-A JEONG ; Jung-Min BAE ; Jae-Seok MIN ; Hyun-dong CHAE ; Sung Gon KIM ; Daegeun PARK ; Dong Baek KANG ; Hogoon KIM ; Seung Soo LEE ; Sung Il CHOI ; Seong Ho HWANG ; Su-Mi KIM ; Moon Soo LEE ; Sang Hyun KIM ; Sang-Ho JEONG ; Yusung YANG ; Yonghae BAIK ; Sang Soo EOM ; Inho JEONG ; Yoon Ju JUNG ; Jong-Min PARK ; Jin Won LEE ; Jungjai PARK ; Ki Han KIM ; Kyung-Goo LEE ; Jeongyeon LEE ; Seongil OH ; Ji Hun PARK ; Jong Won KIM ; The Information Committee of the Korean Gastric Cancer Association
Journal of Gastric Cancer 2025;25(1):115-132
Purpose:
Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023.
Materials and Methods:
The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys.
Results:
Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively.
Conclusions
The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Result Analysis
Print
Save
E-mail