1.Association of T2-Weighted Imaging Features in Invasive Breast Cancer With Clinicopathologic Features and Neoadjuvant Treatment Outcomes
Inyoung YOUN ; Yun Ho ROH ; Min Jung KIM ; Jung Hyun YOON ; Mi-ri KWON ; Vivian Youngjean PARK
Korean Journal of Radiology 2026;27(4):305-317
Objective:
To investigate the associations between T2-weighted imaging (T2WI) features and clinicopathologic characteristics in invasive breast cancer, as well as their relationship with treatment response to neoadjuvant chemotherapy (NAC).
Materials and Methods:
This retrospective study included 179 women with invasive breast cancer who underwent preoperative 3T breast MRI between November 2020 and February 2021. Intratumoral T2 signal intensity (SI) and peritumoral edema were graded on T2WI, and T2 relaxation times were calculated both including and excluding necrotic or cystic areas. T2 relaxation times were compared across T2 SI grades using the Kruskal–Wallis test. Associations between T2 features and clinicopathologic factors were assessed using chi-square tests and logistic regression analyses. In patients who received NAC (n = 68), associations between T2 features and NAC outcomes were also evaluated.
Results:
Higher intratumoral T2 SI and peritumoral edema grades were significantly associated with longer T2 relaxation times (P < 0.001). Intratumoral T2 SI grades were associated with higher clinical T category, axillary lymph node metastasis, and tumor multiplicity (all P < 0.05). Longer intratumoral T2 relaxation times were associated with higher clinical T category, hormone receptor (HR) negativity, and the triple-negative subtype (all P < 0.05), even after excluding necrotic or cystic areas.Higher peritumoral edema grades were associated with advanced clinical T category, HR negativity, and the triple-negative subtype (all P < 0.05). T2 relaxation times of peritumoral edema showed no significant associations, except with higher clinical T category (P = 0.005) and estrogen receptor status (P = 0.030). In the NAC subgroup, higher intratumoral T2 SI grades and longer T2 relaxation times were significantly associated with disease progression during NAC (P < 0.05), but not with non-pathologic complete response. Peritumoral edema showed no significant association with NAC outcomes (P > 0.05).
Conclusion
T2-weighted MRI features were associated with clinicopathologic factors, including clinical T category, HR status, triple-negative subtype, and disease progression during NAC.
2.Comparison of Digital Mammography Plus Full ABUS Review and Digital Mammography Plus Selective ABUS Review Guided by ABUS Artificial Intelligence–Computer-Aided Diagnosis for Breast Cancer Screening
Inyoung YOUN ; Su Min HA ; Myoung-jin JANG ; Mi-ri KWON ; Jung Min CHANG
Korean Journal of Radiology 2026;27(2):111-121
Objective:
To compare two breast cancer screening strategies, digital mammography (DM) plus radiologist-interpreted automated breast ultrasound (ABUS) and DM plus selective ABUS review, in which only examinations positive for DM or flagged by ABUS artificial intelligence–computer-aided diagnosis (AI-CAD) were reviewed by radiologists.
Materials and Methods:
This retrospective study included asymptomatic women who underwent DM and ABUS screening for breast cancer between March 2022 and March 2023. The radiologists’ interpretations of DM and ABUS without AI assistance (DM + ABUS_radiologist) were collected from the clinical radiology reports. A selective DM plus ABUS reading strategy was simulated, in which only cases interpreted as positive in the radiologist’s DM report or flagged by retrospectively applied ABUS AI-CAD were triaged for further evaluation through a full review by radiologists (DM + ABUS_AI-CAD). The cancer detection rate (CDR), sensitivity, specificity, and abnormal interpretation rate (AIR) were calculated and compared between DM + ABUS_ radiologist and DM + ABUS_AI-CAD groups using the McNemar’s test.
Results:
Among 2,275 women (mean age, 56.1 ± 8.6 years), 12 cancers were diagnosed. The sensitivity, CDR and AIR for DM + ABUS_radiologist was 83.3% (10/12; 95% confidence interval [CI]: 51.6–97.9), 4.4 (10/2,275; 95% CI: 2.1–8.1) per 1,000 screening examinations and 16.7% (379/2,275; 95% CI: 15.1–18.3), respectively. DM + ABUS_AI-CAD triaged 84.0% (1,910/2,275) of the examinations as negative in both DM reports and retrospectively applied ABUS AI-CAD, requiring radiologist reassessment in only 16.0% (365/2,275). This approach reduced the AIR to 7.3% (167/2,275) and improved the specificity from 83.7% (1,894/2,263) to 93.1% (2,107/2,263) (all P < 0.001), while maintaining a CDR of 4.8 per 1,000 and a sensitivity of 91.7% (11/12) (all P > 0.999), compared to the DM + ABUS-radiologist.
Conclusion
An AI-CAD-assisted selective ABUS reading strategy reduces unnecessary recalls and improves specificity, which may help optimize reading priorities and reduce the reading workload while maintaining cancer detection performance.
3.Screening Outcomes of Supplemental Automated Breast Ultrasound in Women With Nondense Breasts Undergoing Mammography
Mi-ri KWON ; Mi Yeon LEE ; Suhyeon MOON ; Eun Sook KO ; Eun Young KO ; Boo Kyung HAN ; Inyoung YOUN ; Yoon Jung CHOI ; Shin Ho KOOK ; Jai Min RYU ; Ji Soo CHOI
Korean Journal of Radiology 2026;27(1):14-26
Objective:
To evaluate the performance of supplemental automated breast ultrasound (ABUS) added to mammography-based breast cancer screening for women with nondense breasts.
Materials and Methods:
A retrospective search of radiology databases at two tertiary institutions identified asymptomatic women with nondense breasts who underwent breast cancer screening using both digital mammography (DM) and supplemental ABUS between January 2020 and December 2023. We excluded women without sufficient follow-up data or those without an established final diagnosis, including histopathologic results. The performance measures of DM alone and ABUS combined with DM (ABUS plus DM) were compared. The primary outcome was the cancer detection rate (CDR), and the secondary outcomes were sensitivity and specificity. Subgroup analyses were performed for women with scattered fibroglandular density and almost entirely fatty breasts.
Results:
A total of 2,904 pairs of screening examinations were performed in 1,683 women (59 ± 10 years), detecting 26 cancers. In comparison with DM alone, ABUS plus DM showed higher CDR (9.0 vs. 7.9 per 1,000 examinations, P < 0.001), higher sensitivity (100% [26/26] vs. 88.5% [23/26], P < 0.001), and lower specificity (95.0% [2,735/2,878] vs. 97.9% [2,817/2,878], P < 0.001). In women with scattered fibroglandular density, ABUS increased the CDR from 7.4 to 8.5 per 1,000 examinations and improved the sensitivity from 87.0% [20/23] to 100% [23/23] (P < 0.001). In women with almost entirely fatty breasts, ABUS plus DM showed the same CDR (16.4 per 1,000 examinations) and sensitivity (100% [3/3]) as DM alone. Three cancers (11.5% [3/26]), all of which were stage T1N0, were detected only by supplemental ABUS.
Conclusion
Supplemental ABUS improved cancer detection and sensitivity in women with nondense breasts, with the benefits primarily observed in those with scattered fibroglandular density.
6.Comparative analysis of surgical outcomes of laparoscopic appendectomy performed by six surgeons with different subspecialties: a retrospective cohort study using risk-adjusted cumulative summation
Ji Hyeong SONG ; Inyoung NA ; Song-Yi KIM ; Youn Ju LEE ; Sun Jong HAN ; Sang Il YOUN ; Sa-Hong MIN ; Jin Soo KIM
Annals of Surgical Treatment and Research 2025;109(3):207-214
Purpose:
Laparoscopic appendectomy, a routine surgical procedure for acute appendicitis, is commonly performed in general hospitals. However, postoperative outcomes based on surgical subspecialty have not been well established. This study aimed to compare surgical outcomes of laparoscopic appendectomy across different surgical subspecialties using risk-adjusted cumulative summation (RA-CUSUM) analysis.
Methods:
A retrospective analysis was conducted on 631 patients undergoing laparoscopic appendectomy between July 2020 and December 2022. Surgeons were categorized into gastrointestinal (GI) or non-GI groups and senior or young groups. Surgical failure was defined as operation time exceeding the mean plus 2 standard deviations, presence of postoperative complications, or readmission within 30 days after surgery. RA-CUSUM analysis was employed to evaluate surgical failure within each group.
Results:
The GI group performed more partial cecectomies (P = 0.017) and had longer operation times (P = 0.019) than the non-GI group. The senior group exhibited shorter operation time (P < 0.001), reduced length of stay (P = 0.011), and a higher complication rate (P < 0.001) than the young group. RA-CUSUM analysis indicated a decrease in surgical failure as accumulation progressed in both senior and young groups, as well as in the GI and non-GI groups.
Conclusion
Outcomes of laparoscopic appendectomy varied by subspecialty and length of experience. However, each surgeon showed trends of decreasing surgical failure over time. These results suggest that the surgeon’s subspecialty minimally affects the outcomes of laparoscopic appendectomy, reflecting its fundamental nature within general surgery.
7.Unenhanced Breast MRI With Diffusion-Weighted Imaging for Breast Cancer Detection: Effects of Training on Performance and Agreement of Subspecialty Radiologists
Yeon Soo KIM ; Su Hyun LEE ; Soo-Yeon KIM ; Eun Sil KIM ; Ah Reum PARK ; Jung Min CHANG ; Vivian Youngjean PARK ; Jung Hyun YOON ; Bong Joo KANG ; Bo La YUN ; Tae Hee KIM ; Eun Sook KO ; A Jung CHU ; Jin You KIM ; Inyoung YOUN ; Eun Young CHAE ; Woo Jung CHOI ; Hee Jeong KIM ; Soo Hee KANG ; Su Min HA ; Woo Kyung MOON
Korean Journal of Radiology 2024;25(1):11-23
Objective:
To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI).
Materials and Methods:
A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm 2 was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive.The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC).
Results:
Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4–79.9), 90.8% (95% CI: 85.6–94.2), and 83.5% (95% CI: 78.6–87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8–97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9–89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1–79.4; P = 0.58) was observed. Regarding inter-reader agreement, the κ values were 0.57 (95% CI: 0.52–0.63) before training and 0.68 (95% CI: 0.62–0.74) after training, with a difference of 0.11 (95% CI: 0.02–0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69–0.74) before training and 0.79 (95% CI: 0.76–0.80) after training (P = 0.002).
Conclusion
Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.
8.Pharmacokinetics and pharmacodynamics of a fixed-dose combination of gemigliptin/metformin sustained release 25/500 mg compared to the loose combination in healthy male subjects
Xuanyou JIN ; Eunwoo KIM ; Ki Young HUH ; Inyoung HWANG ; Joo-Youn CHO ; Kyung-Sang YU ; SeungHwan LEE
Translational and Clinical Pharmacology 2020;28(1):43-54
A fixed-dose combination (FDC) of gemigliptin/metformin can improve the medication adherence in patients with type 2 diabetes mellitus (T2DM). In this study, the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of gemigliptin and metformin were compared between FDC and the corresponding loose combination under fasted and fed states. A two-part, randomized, open label, single-dose, two-way crossover study was conducted in healthy male subjects. Under fasted (part 1) or fed (part 2) state, 2 FDC tablets of gemigliptin/metformin sustained release (SR) 25/500 mg or loose combination with one tablet of gemigliptin 50 mg and two tablets of metformin extended release (XR) 500 mg were orally administered in each period with a 7-day washout. Serial blood samples were collected up to 48 hours to determine the drug concentration and the dipeptidyl peptidase 4 (DPP-4) activity. The concentration-time profiles of gemigliptin and metformin were similar between FDC and loose combination in both the fasted and fed states. Geometric mean ratios and 90% confidence intervals of FDC to loose combination for area under the concentration-time curve and maximum plasma concentration of gemigliptin and metformin were within the bioequivalence range (0.8–1.25) in both states. DPP-4 activity-time profiles of FDC were comparable to that of the loose combination, showing similar area under the DPP-4 inhibition-time curve and maximum DPP-4 inhibition between FDC and loose combination, regardless of the fasted or fed state. In conclusion, the PK/PD characteristics of gemigliptin and metformin were similar in FDC tablets and loose combination both in fasted and fed states.
9.Metastasis of Poorly Differentiated Thyroid Carcinoma to the Sternum: A Case Report
Journal of the Korean Radiological Society 2020;81(4):99-944
Sternal metastasis of poorly differentiated thyroid carcinoma (PDTC) is rare, and only a few cases have been reported in the literature. Here, we report a case of sternal metastasis of PDTC in an 83-year-old woman, 2 years after right hemithyroidectomy, treated with sternal resection and reconstruction.
10.Novel alternative for submental intubation - A case report -
Inyoung JUNG ; Byung Hoon YOO ; Ji Youn JU ; Sijin CHOI ; Jun Heum YON ; Kye-Min KIM ; Yun-Hee LIM ; Woo Yong LEE
Anesthesia and Pain Medicine 2020;15(2):247-250
Background:
Submental intubation is commonly used during general anesthesia for maxillofacial surgeries as it provides a safe unrestricted surgical access compared to tracheostomy. During submental intubation, soft tissues and blood clots can become lodged in the endotracheal tube. To overcome this problem, we used a laparoscopic trocar.Case: A 52-year-old man with maxillofacial injury was scheduled to undergo an open reduction and internal fixation. We performed submental intubation using laparoscopic trocar, which created sufficient space for the insertion of the endotracheal tube. Unlike conventional methods, our method did not require any blunt dissection and caused significantly less soft tissue damage and required significantly less time.
Conclusions
Submental intubation with laparoscopic trocar is a one-step method and is quick and easy-to-perform technique with less complications.

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