Youngwoo Kim

Prof. Youngwoo Kim

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2015 in Radiology
Verified
Journal Article
Closed access
SYShota Yamamoto
Shota Yamamoto
WHWonshik Han
Wonshik Han
YKYoungwoo Kim
Youngwoo Kim
LDLiutao Du
Liutao Du
NJNeema Jamshidi
Neema Jamshidi
MKMichael D. Kuo
Michael D. Kuo
The authors of this study performed a radiogenomic analysis of women with breast cancer to study the multiscale relationships among quantitative computer vision–extracted dynamic contrast material–enhanced MR imaging phenotypes, early metastasis, and long noncoding RNA expression determined by means of high-resolution next-generation RNA sequencing. PurposeTo perform a radiogenomic analysis of women with breast cancer to study the multiscale relationships among quantitative computer vision–extracted dynamic contrast material–enhanced (DCE) magnetic resonance (MR) imaging phenotypes, early metastasis, and long noncoding RNA (lncRNA) expression determined by means of high-resolution next-generation RNA sequencing.Materials and MethodsIn this institutional review board–approved study, an automated image analysis platform extracted 47 computational quantitative features from DCE MR imaging data in a training set (n = 19) to screen for MR imaging biomarkers indicative of poor metastasis-free survival (MFS). The lncRNA molecular landscape of the candidate feature was defined by using an RNA sequencing–specific negative binomial distribution differential expression analysis. Then, this radiogenomic biomarker was applied prospectively to a validation set (n = 42) to allow prediction of MFS and lncRNA expression by using quantitative polymerase chain reaction...

1 April 2016 in Clinical Journal of the American Society of Nephrology
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Journal Article
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YKYoungwoo Kim
Youngwoo Kim
YGYinghui Ge
Yinghui Ge
CTCheng Tao
Cheng Tao
JZJianbing Zhu
Jianbing Zhu
ACArlene B. Chapman
Arlene B. Chapman
KBKyongtae T. Bae
Kyongtae T. Bae
Background and objectives Our study developed a fully automated method for segmentation and volumetric measurements of kidneys from magnetic resonance images in patients with autosomal dominant polycystic kidney disease and assessed the performance of the automated method with the reference manual segmentation method. Design, setting, participants, & measurements Study patients were selected from the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease. At the enrollment of the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease Study in 2000, patients with autosomal dominant polycystic kidney disease were between 15 and 46 years of age with relatively preserved GFRs. Our fully automated segmentation method was on the basis of a spatial prior probability map of the location of kidneys in abdominal magnetic resonance images and regional mapping with total variation regularization and propagated shape constraints that were formulated into a level set framework. T2–weighted magnetic resonance image sets of 120 kidneys were selected from 60 patients with autosomal dominant polycystic kidney disease and divided into the training and test datasets. The performance of the automated method in reference to the manual method was assessed by means of two metrics: Dice similarity coefficient and intraclass correlation coefficient of segmented kidney volume. The training and test sets were swapped for crossvalidation and reanalyzed. Results Successful segmentation of kidneys was performed with the automated method in all test patients. The segmented kidney volumes ranged from 177.2 to 2634 ml (mean, 885.4±569.7 ml). The mean Dice similarity coefficient ±SD between the automated and manual methods was 0.88±0.08. The mean correlation coefficient between the two segmentation methods for the segmented volume measurements was 0.97 (P<0.001 for each crossvalidation set). The results from the crossvalidation sets were highly comparable. Conclusions We have developed a fully automated method for segmentation of kidneys from abdominal magnetic resonance images in patients with autosomal dominant polycystic kidney disease with varying kidney volumes. The performance of the automated method was in good agreement with that of manual method.

1 August 2022 in Journal of the American Society of Nephrology
Verified
Journal Article
Closed access
YKYoungwoo Kim
Youngwoo Kim
CTCheng Tao
Cheng Tao
HKHyungchan Kim
Hyungchan Kim
GOGeum-Yoon Oh
Geum-Yoon Oh
JKJeongbeom Ko
Jeongbeom Ko
KBKyongtae T. Bae
Kyongtae T. Bae
Background: Total kidney volume (TKV) is an important imaging biomarker in autosomal dominant polycystic kidney disease (ADPKD). Manual computation of TKV, particularly with the exclusion of exophytic cysts, is laborious and time consuming. Methods: We developed a fully automated segmentation method for TKV using a deep learning network to selectively segment kidney regions while excluding exophytic cysts. We used abdominal T2 -weighted magnetic resonance images from 210 individuals with ADPKD who were divided into two groups: one group of 157 to train the network and a second group of 53 to test it. With a 3D U-Net architecture using dataset fingerprints, the network was trained by K-fold cross-validation, in that 80% of 157 cases were for training and the remaining 20% were for validation. We used Dice similarity coefficient, intraclass correlation coefficient, and Bland–Altman analysis to assess the performance of the automated segmentation method compared with the manual method. Results: The automated and manual reference methods exhibited excellent geometric concordance (Dice similarity coefficient: mean±SD, 0.962±0.018) on the test datasets, with kidney volumes ranging from 178.9 to 2776.0 ml (mean±SD, 1058.5±706.8 ml) and exophytic cysts ranging from 113.4 to 2497.6 ml (mean±SD, 549.0±559.1 ml). The intraclass correlation coefficient was 0.9994 (95% confidence interval, 0.9991 to 0.9996; P<0.001) with a minimum bias of −2.424 ml (95% limits of agreement, −49.80 to 44.95). Conclusions: We developed a fully automated segmentation method to measure TKV that excludes exophytic cysts and has an accuracy similar to that of a human expert. This technique may be useful in clinical studies that require automated computation of TKV to evaluate progression of ADPKD and response to treatment.

26 May 2017 in Journal of Magnetic Resonance Imaging
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YKYoungwoo Kim
Youngwoo Kim
AFAlessandro Furlan
Alessandro Furlan
ABAmir A. Borhani
Amir A. Borhani
KBKyongtae T. Bae
Kyongtae T. Bae

16 June 2003 in Journal of Polymer Science Part B: Polymer Physics
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HLHyuneui Lim
Hyuneui Lim
YLYeonhee Lee
Yeonhee Lee
SHSeunghee Han
Seunghee Han
YKYoungwoo Kim
Youngwoo Kim
JSJu-Myung Song
Ju-Myung Song
JKJoon-Seop Kim
Joon-Seop Kim

25 October 2016 in Physics in Medicine & Biology
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YKYoungwoo Kim
Youngwoo Kim
SBSonu K Bae
Sonu K Bae
TCTianming Cheng
Tianming Cheng
CTCheng Tao
Cheng Tao
YGYinghui Ge
Yinghui Ge
KBKyongtae T Bae
Kyongtae T Bae
Liver and liver cyst volume measurements are important quantitative imaging biomarkers for assessment of disease progression in autosomal dominant polycystic kidney disease (ADPKD) and polycystic liver disease (PLD). To date, no study has presented automated segmentation and volumetric computation of liver and liver cysts in these populations. In this paper, we proposed an automated segmentation framework for liver and liver cysts from bounded abdominal MR images in patients with ADPKD. To model the shape and variations in ADPKD livers, the spatial prior probability map (SPPM) of liver location and the tissue prior probability maps (TPPMs) of liver parenchymal tissue intensity and cyst morphology were generated. Formulated within a three-dimensional level set framework, the TPPMs successfully captured liver parenchymal tissues and cysts, while the SPPM globally constrained the initial surfaces of the liver into the desired boundary. Liver cysts were extracted by combined operations of the TPPMs, thresholding, and false positive reduction based on spatial prior knowledge of kidney cysts and distance map. With cross-validation for the liver segmentation, the agreement between the radiology expert and the proposed method was 84% for shape congruence and 91% for volume measurement assessed by the intra-class correlation coefficient (ICC). For the liver cyst segmentation, the agreement between the reference method and the proposed method was ICC = 0.91 for cyst volumes and ICC = 0.94 for % cyst-to-liver volume.