Publications by authors named "S F Lee"

107,710 Publications

Metallic Artifact Reduction of Multiacquisition With Variable Resonance Image Combination Selective-Short Tau Inversion Recovery for Postoperative Cervical Spine With Artificial Disk Replacement: A Preliminary Study.

J Comput Assist Tomogr 2022 Jan 25. Epub 2022 Jan 25.

From the Department of Radiology, College of Medicine, Inha University, Jung-gu, Incheon Department of Radiology, Hanyang University School of Medicine, Seoul Hospital, Seoul, Korea Department of Radiology, Stanford University, Stanford, CA Department of Neurosurgery, College of Medicine, Inha University, Jung-gu, Incheon Department of Pathology, National Police Hospital, Seoul, South Korea.

Objective: This study aimed to evaluate multiacquisition with variable resonance image combination selective short tau inversion recovery (MAVRIC SL STIR) for metallic artifact reduction in magnetic resonance imaging (MRI) of postoperative cervical spine with artificial disk replacement.

Methods: A porcine cervical spine with artificial disk replacement was subject to 3 T MRI with variable fat-suppressed fluid-sensitive sequences. Five volunteers underwent MRI with MAVRIC SL STIR and STIR. Quantitative and qualitative analyses were performed for metallic artifact reduction.

Results: MAVRIC SL STIR showed the least signal void areas in the tissue phantom and volunteer study. In the tissue phantom study, MAVRIC SL STIR showed the best visualization of anatomic structure, least distortion, and signal pile-up. However, it ranked last for the homogeneity of fat suppression among sequences. In the volunteer study, MAVRIC SL STIR showed better visualization of anatomic structure and lesser distortion, but showed worse image quality of the spinal cord than STIR in the sagittal plane (P < 0.05).

Conclusions: MAVRIC SL STIR might be useful for visualization of anatomy by reduction of signal void areas and distortion in the operated site but should be used as a complement to STIR for evaluation of the spinal cord signal change.
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http://dx.doi.org/10.1097/RCT.0000000000001266DOI Listing
January 2022

Three FDA-approved therapies for chronic GVHD.

Blood 2022 Jan 26. Epub 2022 Jan 26.

Fred Hutchinson Cancer Research Center, SEATTLE, Washington, United States.

Chronic graft-versus-host disease (cGVHD) is a major immunological complication of allogeneic hematopoietic cell transplantation. Chronic GVHD involves multiple organs, reduces quality of life and often requires prolonged therapy with glucocorticoids, causing severe side effects. After four decades of testing multiple therapeutic approaches, the drugs ibrutinib, belumosudil and ruxolitinib were FDA-approved for cGVHD in the last four years. Here we put a spotlight on their mechanisms of action, the studies that led to approval, and their future role in cGVHD.
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http://dx.doi.org/10.1182/blood.2021014448DOI Listing
January 2022

Bioinspired Toughening Mechanisms in a Multilayer Transparent Conductor Structure.

ACS Appl Mater Interfaces 2022 Jan 26. Epub 2022 Jan 26.

With increasing demands and interest in flexible and foldable devices, much effort has been devoted to the development of flexible transparent electrodes. An in-depth understanding of failure mechanisms in nanoscale structure is crucial in developing stable, flexible electronics with long-term durability. The present work investigated the mechanoelectric characteristics of transparent conductive electrodes in the form of dielectric/metal/dielectric (DMD) sandwich structures under bending, including one time and repeated cyclic bending test, and provides an explanation of their failure mechanism. We demonstrate how a thin metallic layer helps to enhance the mechanical robustness of the DMD as compared with that without, tune the mechanical properties of the cohesive layer, and improve the electrode fracture resistance. Abnormal crack propagation and toughening of multilayer DMD structures are analyzed, and its underlying mechanisms are explained. We consider the knowledge of the failure mechanisms of transparent conductive electrodes gained from the present study as a foundation for future design improvements.
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http://dx.doi.org/10.1021/acsami.1c21923DOI Listing
January 2022

Association of Plaque Location and Vessel Geometry Determined by Coronary Computed Tomographic Angiography With Future Acute Coronary Syndrome-Causing Culprit Lesions.

JAMA Cardiol 2022 Jan 26. Epub 2022 Jan 26.

Department of Cardiovascular Medicine, National Heart Centre, Singapore.

Importance: Distinct plaque locations and vessel geometric features predispose to altered coronary flow hemodynamics. The association between these lesion-level characteristics assessed by coronary computed tomographic angiography (CCTA) and risk of future acute coronary syndrome (ACS) is unknown.

Objective: To examine whether CCTA-derived adverse geometric characteristics (AGCs) of coronary lesions describing location and vessel geometry add to plaque morphology and burden for identifying culprit lesion precursors associated with future ACS.

Design, Setting, And Participants: This substudy of ICONIC (Incident Coronary Syndromes Identified by Computed Tomography), a multicenter nested case-control cohort study, included patients with ACS and a culprit lesion precursor identified on baseline CCTA (n = 116) and propensity score-matched non-ACS controls (n = 116). Data were collected from July 20, 2012, to April 30, 2017, and analyzed from October 1, 2020, to October 31, 2021.

Exposures: Coronary lesions were evaluated for the following 3 AGCs: (1) distance from the coronary ostium to lesion; (2) location at vessel bifurcations; and (3) vessel tortuosity, defined as the presence of 1 bend of greater than 90° or 3 curves of 45° to 90° using a 3-point angle within the lesion.

Main Outcomes And Measures: Association between lesion-level AGCs and risk of future ACS-causing culprit lesions.

Results: Of 548 lesions, 116 culprit lesion precursors were identified in 116 patients (80 [69.0%] men; mean [SD], age 62.7 [11.5] years). Compared with nonculprit lesions, culprit lesion precursors had a shorter distance from the ostium (median, 35.1 [IQR, 23.6-48.4] mm vs 44.5 [IQR, 28.2-70.8] mm), more frequently localized to bifurcations (85 [73.3%] vs 168 [38.9%]), and had more tortuous vessel segments (5 [4.3%] vs 6 [1.4%]; all P < .05). In multivariable Cox regression analysis, an increasing number of AGCs was associated with a greater risk of future culprit lesions (hazard ratio [HR] for 1 AGC, 2.90 [95% CI, 1.38-6.08]; P = .005; HR for ≥2 AGCs, 6.84 [95% CI, 3.33-14.04]; P < .001). Adverse geometric characteristics provided incremental discriminatory value for culprit lesion precursors when added to a model containing stenosis severity, adverse morphological plaque characteristics, and quantitative plaque characteristics (area under the curve, 0.766 [95% CI, 0.718-0.814] vs 0.733 [95% CI, 0.685-0.782]). In per-patient comparison, patients with ACS had a higher frequency of lesions with adverse plaque characteristics, AGCs, or both compared with control patients (≥2 adverse plaque characteristics, 70 [60.3%] vs 50 [43.1%]; ≥2 AGCs, 92 [79.3%] vs 60 [51.7%]; ≥2 of both, 37 [31.9%] vs 20 [17.2%]; all P < .05).

Conclusions And Relevance: These findings support the concept that CCTA-derived AGCs capturing lesion location and vessel geometry are associated with risk of future ACS-causing culprit lesions. Adverse geometric characteristics may provide additive prognostic information beyond plaque assessment in CCTA.
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http://dx.doi.org/10.1001/jamacardio.2021.5705DOI Listing
January 2022

Correction of an adult Class III malocclusion through regaining of orthodontic space and an implant restoration.

J Esthet Restor Dent 2022 Jan 26. Epub 2022 Jan 26.

Division of Orthodontics, Department of Dentistry, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.

This case report describes the interdisciplinary treatment of a 23-year-old female with Class III malocclusion and a missing maxillary left second premolar. Treatment alternatives were discussed, and the selected treatment plan was presented to illustrate a way to gain space for the premolar implant restoration and correct Class III relationship through maxillary molar retraction followed by maxillary total arch protraction with a palatal temporary skeletal anchorage device. Esthetic anterior alignment and functional occlusal rehabilitation was achieved, and facial balance was maintained at the end of treatment. CLINICAL SIGNIFICANCE: Implant restoration in conjunction with regaining orthodontic space by a team of multidisciplinary dental specialists presents an effective treatment solution to permanent tooth agenesis. Class III malocclusion can be treated with a combination of maxillary protraction and mandibular retraction using temporary skeletal anchorage devices. The versatility of modified palatal C-plates presents greater clinical application when related side effects are controlled with solid understanding of their biomechanics.
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http://dx.doi.org/10.1111/jerd.12870DOI Listing
January 2022
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