Publications by authors named "Heon Ju Kwon"

51 Publications

Hepatic volume profiles in potential living liver donors with anomalous right-sided ligamentum teres.

Abdom Radiol (NY) 2020 Oct 16. Epub 2020 Oct 16.

Division of Liver Transplantation and Hepatobiliary Surgery, and Departments of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Purpose: In living liver donors with rare anatomical anomaly of right-sided ligamentum teres (RSLT), right or left hemiliver procurement is commonly contraindicated. The purpose of this study was to evaluate the hepatic volume profiles in potential donors with RSLT using semi-automated CT volumetry (CTV).

Methods: Among 5535 potential donor candidates in our institution between April 2003 and May 2019, 23 cases of RSLT (0.4%) were included. Proportional liver volumes were measured using semi-automated CTV and compared with those of manual volumetry and intraoperative graft weights (seven surgical cases).

Results: The mean percentage volume of the right posterior section was significantly larger than that of the left hemiliver (38.5 ± 8.4% vs. 23.3 ± 5.7%, P < 0.001). Particularly in independent right lateral type, the mean percentage volume of the right posterior section was about two times larger to that of the left hemiliver (41.5% ± 6.5% vs. 21.9% ± 4.4%, P < 0.001), whereas the volume proportions of these two parts were similar between the two parts in bifurcation and trifurcation types (P = 0.810 and 0.979, respectively). Semi-automated CTV of corresponding whole liver, right posterior section, right anterior section, and left hemiliver showed strong correlations with manual CTV (r = 0.989-0.998; P < 0.001). For the seven surgical cases, the graft weights estimated by semi-automated CTV showed a significant correlation with intraoperative graft weights (r = 0.972; P < 0.001).

Conclusion: In independent right lateral type of RSLT, the right posterior section tends to be significantly larger than left hemiliver, and may be an alternative option for graft in potential living liver donors with this rare anatomical anomaly.
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http://dx.doi.org/10.1007/s00261-020-02803-0DOI Listing
October 2020

Impacts on outcomes and management of preoperative magnetic resonance cholangiopancreatography in patients scheduled for laparoscopic cholecystectomy: for whom it should be considered?

Ann Surg Treat Res 2020 Oct 24;99(4):221-229. Epub 2020 Sep 24.

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.

Purpose: We evaluated the impact of preoperative magnetic resonance cholangiopancreatography (MRCP) on patient outcomes, and found which patients should be considered for MRCP before cholecystectomy.

Methods: We performed retrospective analysis of 2,072 patients that underwent cholecystectomy for benign gallbladder disease from January 2014 to June 2017. Patients were grouped as CT only group (n = 737) and MRCP group (n = 1,335), including both CT and MRCP (n = 1,292) or MRCP only (n = 43). The main outcome measure was associated with complications after cholecystectomy, and the secondary outcomes were hospital stay, readmission, and events that could impact patient management due to addition of MRCP.

Results: There were no statistical differences in occurrence of intraoperative or postoperative complications or readmission rate between the 2 groups. Hospital stay was about 0.6 days longer in the MRCP group. However, MRCP group was more susceptible to complications due to underlying patient demographics (older age, higher frequency of diabetes, and higher level of the inflammatory markers). MRCP diagnosed common bile duct (CBD) stones in 6.5% of patients (84/1,292) without CBD stones in CT, and bile duct anomalies were identified in 41 patients (3.2%). Elevated γ-GT was the only independent factor for additional detection of CBD stones (adjusted odds ratio [OR], 2.89; P = 0.029) and subsequent biliary procedures (adjusted OR, 3.34; P = 0.018) when additional MRCP was performed.

Conclusion: MRCP is valuable for identification of bile duct variation and CBD stones. Preoperative MRCP can be considered, particularly in patients with elevated γ-GT, for proper preoperative management and avoidance of complications.
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http://dx.doi.org/10.4174/astr.2020.99.4.221DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7520229PMC
October 2020

Importance of Imaging Plane of Gadoxetic Acid--Enhanced Magnetic Resonance Cholangiography for Bile Duct Anatomy in Healthy Liver Donors.

Transplant Proc 2021 Jan-Feb;53(1):49-53. Epub 2020 Sep 12.

(a)Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea; (b)Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea; (c)Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Purpose: The purpose of this study was to compare the image quality and accuracy of axial vs coronal contrast-enhanced magnetic resonance cholangiography (CE-MRC) for assessing bile duct anatomy.

Methods: Data from 313 healthy donors who underwent axial and coronal CE-MRC before liver donation were retrospectively analyzed. Motion artifacts and bile duct visibility were assessed using 4-point scales, with scores ≥3 considered interpretable. The sensitivity and specificity of axial and coronal CE-MRC for diagnosing anatomic variations were compared, as were the proportions of correctly categorized biliary anatomic types.

Results: Axial CE-MRC provided better image quality than coronal CE-MRC in terms of both motion artifacts (3.83 vs 3.17; P < .001) and duct visibility (3.50 vs 3.17, P < .001), resulting in more interpretable images with axial than coronal CE-MRC (92.7% vs 82.1%; P < .001). Among 249 donors with interpretable images, coronal CE-MRC performed significantly better for identifying duct anatomic variation than axial CE-MRC (sensitivity, 96.9% vs 80.4%, P < .001; specificity, 100% vs 96.7%, P = .025). Coronal CE-MRC was significantly better than axial CE-MRC at correctly categorizing anatomic types of right posterior hepatic duct into left hepatic duct and accessory duct with incomplete right hepatic duct.

Conclusions: With interpretable image quality, coronal CE-MRC performed better than axial CE-MRC for evaluating bile duct anatomy.
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http://dx.doi.org/10.1016/j.transproceed.2020.08.008DOI Listing
September 2020

Reproducibility and reliability of computed tomography volumetry in estimation of the right-lobe graft weight in adult-to-adult living donor liver transplantation: Cantlie's line vs portal vein territorialization.

J Hepatobiliary Pancreat Sci 2020 Aug 19;27(8):541-547. Epub 2020 May 19.

Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background/purpose: In living-donor liver transplantation (LDLT), liver volume assessment is a mandatory step in determining donor appropriateness. This study aimed to compare reliability and reproducibility between two major methods to define virtual hepatectomy plane, based on Cantlie's line (CTV-Cantlie) and portal vein territorialization (CTV-PVT) for right-lobe graft weight estimation in LDLT.

Methods: A total of 188 donors who underwent preoperative CT scans were included. The liver was divided into right and left lobes using CTV-Cantlie and CTV-PTV measurements by two readers. Intraclass correlation coefficient (ICC) was used to determine interreader variability of hepatic weight measured using each CTV method. Intraoperative graft weight (IOW) was used as reference standard of right-lobe graft weight. Pearson correlation test was performed to determine correlation coefficients between presumed graft weight by each CTV method and IOW.

Results: Intraclass correlation coefficients for total liver weight were roughly equivalent between the two CTV methods (CTV-Cantlie: 0.965 [95% CI, 0.954-0.974], CTV-PVT: 0.977 [0.970-0.983]). However, ICCs of right-and left-lobe weights between two readers were higher with CTV-PVT (0.997 and 0.850) than with CTV-Cantlie (0.829 and 0.668). The IOW was 716.0 ± 162.0 g. Correlation coefficients between presumed graft weight by CTV-Cantlie or CTV-PVT and IOW were 0.722 and 0.807, respectively (both P < .001).

Conclusions: For estimation of the right-lobe graft weight in LDLT, CTV-PVT may provide higher reliability and reproducibility than CTV-Cantlie.
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http://dx.doi.org/10.1002/jhbp.749DOI Listing
August 2020

Lifestyle Modification Leads to Spatially Variable Reduction in Hepatic Steatosis in Potential Living Liver Donors.

Liver Transpl 2020 04;26(4):487-497

Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

The spatial variability of hepatic fat reduction in potential living liver donors with hepatic steatosis (HS) who undergo lifestyle modification has not been investigated. Here, we aimed to examine the intrasegmental and intersegmental variability of changes in liver attenuation on computed tomography (CT) in potential living liver donors with HS after diet modification and exercise. A total of 87 living liver donor candidates (30.5 ± 7.0 years; 74 males) with biopsy-proven macrovesicular fat (MaF) ≥10% were included. All underwent diet modification and exercise to improve HS, baseline and follow-up unenhanced CT scans, and liver biopsies. Attenuation and its variability (mean and standard deviation, respectively, in Hounsfield units) in segmental, lobar, superficial, deep, and whole areas of the liver were measured across 32 different regions of interest on both baseline and follow-up CT. At baseline, the right lobe and superficial areas of liver showed significantly lower and more variable attenuation than left lobe and deep areas. Greater variability was noted in patients with more severe HS. Mean interval changes in liver attenuation and variability before and after diet modification and exercise were 13.7 (range, -10.6 to 46.2) and 4.7 (1.6-10.6), respectively. The mean interval change in liver attenuation was significantly higher in the right lobe than in the left (14.7 versus 12.7; P < 0.001), and in superficial areas than in deep areas (14.0 versus 13.4; P = 0.02). Greater variability and larger interval changes in liver attenuation were noted in those who responded (≥20% decrease in MaF) to diet modification and exercise than in those who did not. In conclusion, potential living liver donors with HS show significant intrasegmental and intersegmental variability in hepatic fat reduction on CT before and after diet modification and exercise.
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http://dx.doi.org/10.1002/lt.25733DOI Listing
April 2020

Prevalence of significant hepatic fibrosis using magnetic resonance elastography in a health check-up clinic population.

Aliment Pharmacol Ther 2020 02;51(3):388-396

Division of Gastroenterology and Hepatology, Stanford University Medical Center, Palo Alto, CA, USA.

Background: Significant hepatic fibrosis is associated with higher mortality. However, data on the estimated prevalence of liver fibrosis in the general population are scarce.

Aim: To use magnetic resonance elastography (MRE) to investigate the prevalence of hepatic fibrosis in a Korean health check-up clinic cohort.

Methods: We enrolled 2170 participants at our health check-up clinic between January 2015 and May 2018, all of whom had MR with chemical shift technique and MRE. The primary objective was to estimate the prevalence of liver fibrosis. For generalisation, sex- and age-standardised prevalence was calculated based on the Korean Statistical Information Service (KOSIS) during the period 2015-2018.

Results: The prevalence of F2 (≥3.0 kPa) and F3 (≥3.6 kPa) in the overall cohort was 5.1% and 1.3% respectively (sex- and age-adjusted prevalence of 3.8% and 1.3%). Non-alcoholic fatty liver disease (NAFLD) prevalence (>5% fat fraction) was 27.7% in the average risk population (after excluding alcohol use and viral hepatitis), and the prevalence of significant and advanced fibrosis in NAFLD participants was 8.0% and 1.5% respectively. In participants with diabetes, 12.5% had ≥F2 and 4.3% ≥F3. In participants with NAFLD plus diabetes, 24.1% had ≥F2 and 6.0% ≥F3. On multivariate analysis, only age, insulin, diabetes and fatty liver on MR were independently associated with significant fibrosis.

Conclusions: In a Korean health check-up clinic setting, the prevalence of significant and advanced liver fibrosis was 5.1% and 1.3% (sex- and age-adjusted prevalence of 3.8% and 1.3%). The prevalence of advanced liver fibrosis was five times higher for diabetic participants with NAFLD.
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http://dx.doi.org/10.1111/apt.15626DOI Listing
February 2020

The role of multiphase CT in patients with acute postoperative bleeding after liver transplantation.

Abdom Radiol (NY) 2020 01;45(1):141-152

Division of Liver Transplantation and Hepatobiliary Surgery, Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.

Purpose: The aim of this study was to investigate the role of multiphase computed tomography (CT) in patients with acute postoperative bleeding after liver transplantation(LT).

Methods: We retrospectively analyzed multiphase CT images in 270 post-LT bleeding patients between November 2013 and December 2017, with special attention to contrast extravasation (type I, focal or stipple; type II, jet). Patients were classified into conservative management trial and primary therapeutic intervention groups by initial treatment strategy, and then conservative management trial group was subdivided into successful conservative management and conservative management failure groups. On multiphase CT, we evaluated contrast extravasation volume, rate, and patterns (focal or stipple vs. jet). The concordances of the bleeding source determined by multiphase CT to the actual bleeding source were analyzed.

Results: Of 270 patients, 134 contrast extravasation sites were identified in 116 (43.0%) patients. Most (94.8%, 146/154) of patients without contrast extravasation was successfully managed by conservative management. The mean volume and rate of contrast extravasation significantly increased in order of successful conservative management, conservative management failure, and primary therapeutic intervention groups (all p < 0.01). In subgroup analysis, jet pattern contrast extravasation was more commonly observed with conservative management failure group (p = 0.01). In addition, the change in pattern of contrast extravasation from type I to II was significantly related to the conservative management failure (OR 10.3; 95% CI 1.8-60.4; p = 0.01). There was substantial agreement in localization of bleeding source between multiphase CT and surgery or angiography (Cohen Kappa = 0.78).

Conclusion: Multiphase CT is helpful in the assessment for need of therapeutic intervention and to determine the treatment of choice in recipient with post-LT bleeding.
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http://dx.doi.org/10.1007/s00261-019-02347-yDOI Listing
January 2020

Visibility of B1 and Right/Left Dissociation Using Gd-EOB-DTPA-enhanced T1-weighted Magnetic Resonance Cholangiography in Live Liver Transplant Donors.

Transplant Proc 2019 Oct 19;51(8):2735-2739. Epub 2019 Jul 19.

Division of Liver Transplantation and Hepatobiliary Surgery, Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.

Purpose: We aimed to determine the visibility of bile ducts of the caudate lobe (B1s) and right/left (R/L) dissociation on contrast-enhanced T1-magentic resonance cholangiography after gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid administration (CE-T1-MRC) in live liver donors.

Materials And Methods: In 300 live liver donors who underwent CE-T1-MRC, the visibility and R/L dissociation of B1 were evaluated. Confidence level of B1 visibility and depiction of the presence of R/L dissociation on axial and coronal reconstruction images were compared. Strength of agreement between R/L dissociation on MRC and that on intraoperative cholangiography was evaluated.

Results: At least 1 B1 was visible on CE-T1-MRC in 142 of 300 subjects (47.3%; a total of 195 B1s; 0.64 [SD, 0.80], 0-4 branches per person). Of 195 subjects with visible B1, 55 ducts showed R/L dissociation (28.2%; right-to-left crossover, n = 28; left-to-right crossover, n = 27). The confidence level of B1 visibility on axial images of MRC was significantly higher than that on coronal images of MRC (P < .001). Of 55 B1s with R/L dissociation, axial images were superior to coronal images in depicting B1 crossover in 31 and vice versa in 2 (equal between axial and coronal images in 22). The agreement for R/L dissociation between CE-T1-MRC and intraoperative cholangiography was excellent (κ = 0.819; 95% CI, 0.722-0.917).

Conclusion: Bile ducts of the caudate lobe with R/L dissociation can be occasionally identified on CE-T1-MRC. Axial reconstruction is superior to coronal counterpart.
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http://dx.doi.org/10.1016/j.transproceed.2019.04.085DOI Listing
October 2019

Clinical usefulness of gadoxetic acid-enhanced MRI for evaluating biliary anatomy in living donor liver transplantation.

Eur Radiol 2019 Dec 21;29(12):6508-6518. Epub 2019 Jun 21.

Division of Liver Transplantation and Hepatobiliary Surgery, and Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.

Objectives: To determine the incremental value of hepatobiliary-phase-MRC (HBP-MRC) added to T2-magnetic resonance cholangiography (T2-MRC) for evaluating biliary anatomy in living donor liver transplantation (LDLT) and to correlate T2+HBP-MRC findings with surgical results.

Methods: A total of 276 donors who underwent T2 and gadoxetic acid-enhanced MRI before right hemihepatectomy for LDLT between January and December 2016 were retrospectively enrolled. Two reviewers evaluated biliary anatomy classification using T2-MRC in the first session and T2+HBP-MRC in the second session. The sensitivity, specificity, and confidence level (5-point scale) of T2-MRC and T2+HBP-MRC for variant biliary anatomy were evaluated. The agreement rates between MRC and operative cholangiography for each biliary anatomy classification and the underestimation rates for multiple bile duct openings (BDOs) for both MRC techniques were evaluated.

Results: Of the 276 donors, variant biliary anatomy was observed in 36.2% (100/276). T2+HBP-MRC showed a significantly higher sensitivity for diagnosing variant biliary anatomy than T2-MRC alone (99.0% [99/100] vs. 89.0% [89/100], p = 0.006), with better observer confidence level (4.9 ± 0.3 vs. 4.6 ± 0.7, p < 0.001) and inter-observer agreement (kappa, 0.902 vs. 0.730). Compared with T2-MRC alone, T2+HBP-MRC provided significantly higher agreement with operative cholangiography in biliary anatomy classification (98.6% [272/276] vs. 89.9% [248/276], p < 0.001), and significantly lower underestimation rate for multiple BDOs (5.8% [16/276] vs. 9.4% [26/276], p = 0.002).

Conclusion: T2+HBP-MRC might be considered than T2-MRC alone, as a better depiction of biliary anatomic variations, correlated with surgical findings.

Key Points: •T2+HBP-MRC predicted variant biliary anatomy more accurately than T2-MRC alone. •T2+HBP-MRC might have clinical usefulness by reducing the underestimation rate of multiple bile duct openings, which requires more complicated biliary anastomoses.
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http://dx.doi.org/10.1007/s00330-019-06292-8DOI Listing
December 2019

Diagnostic Performance for Hepatic Artery Occlusion After Liver Transplantation: Computed Tomography Angiography Versus Contrast-Enhanced Ultrasound.

Liver Transpl 2019 11 19;25(11):1651-1660. Epub 2019 Jul 19.

Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

The purpose of this study was to compare the diagnostic performance of computed tomography angiography (CTA) and contrast-enhanced ultrasound (CEUS) when used to diagnose significant hepatic artery occlusion (HAO) in patients that was suspected on Doppler ultrasound (US). Among 3465 adult liver transplantations (LTs) performed between January 2010 and February 2018, 329 recipients were suspected of having HAO by Doppler US. In these patients, 139 recipients who had undergone both CTA and CEUS as second-line studies were included. CTA and CEUS were retrospectively reviewed using the criteria for HAO used in previous studies (CTA, ≥50% stenosis at the anastomosis; CEUS, no HA enhancement or delayed and discontinuous enhancement). The diagnostic values of CTA and CEUS were compared using the McNemar test. CEUS showed statistically significant better accuracy and specificity than CTA in patients with Doppler US abnormality seen after LT (accuracy, 99.3% versus 89.2%, P < 0.001; specificity, 100% versus 83.1%, P < 0.001). CTA had 15 false-positive diagnoses, and CEUS had 1 false-negative diagnosis. In conclusion, CEUS showed higher specificity and positive predictive value than CTA for the diagnosis of HAO in selected patients with a Doppler US abnormality. However, even if there is no HAO diagnosed on CEUS, continuous monitoring and follow-up imaging are required when HAO is strongly suspected in the clinical setting and on CTA.
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http://dx.doi.org/10.1002/lt.25588DOI Listing
November 2019

Dilatation of left portal vein after right portal vein embolization: a simple estimation for growth of future liver remnant.

J Hepatobiliary Pancreat Sci 2019 Jul 10;26(7):300-309. Epub 2019 Jun 10.

Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background: To evaluate correlation between growth rate of left portal vein (LPV) and future liver remnant (FLR) after right portal vein embolization (PVE), and to design models predicting FLR growth rate and volume using LPV area measurements on computed tomography (CT).

Methods: A total of 134 patients (59.6 ± 10.2 years; 103 men) who underwent right PVE with contrast-enhanced CT before and 3-5 weeks after PVE were retrospectively identified. Kinetic hypertrophy ratio (KHR) and kinetic degree of hypertrophy (KDH) served as growth rate parameters. Correlations between LPV growth rate and FLR growth rate and volume change were evaluated by linear regression analysis. The agreements between actual volumetrically determined growth rates and volume of FLR and those estimated from regression equation using LPV measurements were assessed by Bland-Altman plots.

Results: Growth rates of LPV and FLR correlated significantly (P < 0.001). The mean difference between actual and estimated value was 0.1% for KHR-FLR (actual, 9.5 ± 6.0%; estimated, 9.4 ± 3.8%), 0.0% for KDH-FLR (actual, 3.3 ± 1.4%; estimated, 3.3 ± 0.7%), -3.8 cm for FLR volume (actual, 642.5 ± 167.8 cm ; estimated, 646.4 ± 156.5 cm ), and -0.1% for proportion of FLR volume (actual, 48.7 ± 7.8%; estimated, 48.9 ± 7.8%).

Conclusions: After right PVE, FLR growth rate and volume can be simply estimated from the change in LPV area.
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http://dx.doi.org/10.1002/jhbp.633DOI Listing
July 2019

Estimation of the Right Posterior Section Volume in Live Liver Donors: Semiautomated CT Volumetry Using Portal Vein Segmentation.

Acad Radiol 2020 02 3;27(2):210-218. Epub 2019 May 3.

Division of Liver Transplantation and Hepatobiliary Surgery, Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.

Rationale And Objectives: To determine the accuracy of semiautomated CT volumetry using portal vein (PV) segmentation to estimate volume of the right posterior section (RPS) graft compared to intraoperative measured weight (W) in live liver donors.

Materials And Methods: Among 23 donors who donated RPS grafts for liver transplantation in our institution from April 2003 to August 2016, 17 donors with CT scans within 3 months of liver procurement and PV anatomy of type I-III were included. RPS volumes were retrospectively evaluated by semiautomated CT volumetry (RPSV) and by measurement of standard liver volume (SLV) and PV area ratio (RPSV). RPS volumes were compared to W for correlation coefficients, (absolute) difference, and (absolute) percentage deviation. Linear fitting was performed to identify the method that yielded the greatest correlation with W.

Results: Mean values of RPSV, RPSV, and W were 503.4 ± 97.8 mL (346.6-686.0), 516.54 ± 146.20 (274.06-776.32), and 518.8 ± 122.4 (370.0-789.0), respectively. RPSV was strongly correlated with W (r = 0.9414; p < 0.0001), whereas RPSV was only moderately did (r = 0.5899; p = 0.0127). RPSV showed a significantly smaller absolute difference (35.20 ± 30.82 vs. 104.79 ± 60.27, p = 0.004) and absolute percentage deviation (6.61 ± 4.90 vs. 19.92 ± 10.37, p < 0.0001) from W. Equation correlating RPSV and W was W = -74.7191 + 1.1791 RPSV (R = 0.8862; p < 0.001).

Conclusion: RPSV yields smaller absolute difference than RPSV for estimating intraoperative measured weight of RPS in live liver donors. Semiautomated CT volumetry using PV segmentation is feasible for the estimation of the volume of the RPS of the liver, and RPSV was strongly correlated with W (r = 0.9414; p < 0.0001).
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http://dx.doi.org/10.1016/j.acra.2019.03.018DOI Listing
February 2020

Types of posterolateral corner injury associated with both bundle and selective-bundle ACL tears.

Acta Radiol 2019 May 1:284185119842833. Epub 2019 May 1.

2 Department of Orthopaedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.

Background: It is unknown whether a selective-bundle tear of the anterior cruciate ligament (ACL) shows a different prevalence of posterolateral corner (PLC) injury than a both-bundle tear.

Purpose: The prevalence of injury of PLC stabilizer in relation to the type of combined ACL tear (both-bundle and selective-bundle tears) has been investigated.

Material And Methods: This retrospective study included 94 patients who were diagnosed with an ACL tear after knee joint magnetic resonance imaging and underwent arthroscopic surgery. We compared the prevalence of each lesion in relation to the type of ACL injury and the type of selective-bundle tear. We used Fischer exact tests to compare the prevalence of each lesion in relation to the type of ACL injury and the type of selective-bundle tear.

Results: Both-bundle tears occurred in 55 cases (56%) and selective-bundle tears in 39 cases (44%). The most common PLC injury with an ACL tear was inferior popliteomeniscal fascicle (PMF) injury, followed by superior PMF injury. The prevalence of each PLC injury was higher for both-bundle tears than selective-bundle tears, with the exception of popliteus tendon injury diagnosed by reader 1 (P.H.J). However, these differences were statistically significant for superior PMF injury only ( p < 0.05). The prevalence of PLC injury was unrelated to the type of selective-bundle tear (anteromedial vs posterolateral).

Conclusion: Superior PMF injury is more common in both-bundle tears than selective-bundle tears. There is no statistically significant difference in the prevalence of PLC injury between both-bundle tears and selective-bundle tears.
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http://dx.doi.org/10.1177/0284185119842833DOI Listing
May 2019

Breast-specific gamma imaging of invasive breast cancer: Clinicopathologic factors affecting detectability and correlation with mammographic findings.

Clin Imaging 2018 Sep - Oct;51:168-173. Epub 2018 Mar 26.

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, 108 Pyeong-dong, Jongno-gu, Seoul 03181, South Korea.

Purpose: To investigate the factors affecting detectability of invasive breast cancers on BSGI.

Material And Methods: We evaluated BSGI, mammography and pathologic reports of 89 patients with invasive breast cancers.

Results: 87.6% were visible on BSGI. Cancer in old or postmenopausal women were more visible on BSGI (p = 0.003, 0.046). Cancers ≥ 1.0 cm in size were significantly more visible on BSGI than those <1 cm in size (p = 0.002). Cancers in fatty breasts were more visible than those in dense breasts (p = 0.042).

Conclusion: Invasive cancers in older, postmenopausal patients, cancers with size ≥1.0 cm, and those with fatty breast are better visualized by BSGI, than those in younger, premenopausal patients, with size <1.0 cm and dense breast.
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http://dx.doi.org/10.1016/j.clinimag.2018.03.013DOI Listing
December 2018

Diagnostic performance and useful findings of ultrasound re-evaluation for patients with equivocal CT features of acute appendicitis.

Br J Radiol 2018 Feb 9;91(1082):20170529. Epub 2017 Nov 9.

3 Department of Nuclear Medicine , Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine , Seoul, Republic of Korea.

Objective: To evaluate the diagnostic performance of ultrasound and to determine which ultrasound findings are useful to differentiate appendicitis from non-appendicitis in patients who underwent ultrasound re-evaluation owing to equivocal CT features of acute appendicitis.

Methods: 62 patients who underwent CT examinations for suspected appendicitis followed by ultrasound re-evaluation owing to equivocal CT findings were included. Equivocal CT findings were considered based on the presence of only one or two findings among the CT criteria, and ultrasound re-evaluation was done based on a predefined structured report form. The diagnostic performance of ultrasound and independent variables to discriminate appendicitis from non-appendicitis were assessed.

Results: There were 27 patients in the appendicitis group. The overall diagnostic performance of ultrasound re-evaluation was sensitivity of 96.3%, specificity of 91.2% and accuracy of 91.9%. In terms of the performance of individual ultrasound findings, probe-induced tenderness showed the highest accuracy (86.7%) with sensitivity of 74% and specificity of 97%, followed by non-compressibility (accuracy 71.7%, sensitivity 85.2% and specificity 60.6%). The independent ultrasound findings for discriminating appendicitis were non-compressibility (p = 0.002) and increased flow on the appendiceal wall (p = 0.001).

Conclusion: Ultrasound re-evaluation can be used to improve diagnostic accuracy in cases with equivocal CT features for diagnosing appendicitis. The presence of non-compressibility and increased vascular flow on the appendix wall are useful ultrasound findings to discriminate appendicitis from non-appendicitis. Advances in knowledge: Ultrasound re-evaluation is useful to discriminate appendicitis from non-appendicitis when CT features are inconclusive.
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http://dx.doi.org/10.1259/bjr.20170529DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5965797PMC
February 2018

Feasibility of UltraFast Doppler in Post-operative Evaluation of Hepatic Artery in Recipients following Liver Transplantation.

Ultrasound Med Biol 2017 11 23;43(11):2611-2618. Epub 2017 Aug 23.

Division of Liver Transplantation and Hepatobiliary Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

To determine the feasibility of using UltraFast Doppler in post-operative evaluation of the hepatic artery (HA) after liver transplantation (LT), we evaluated 283 simultaneous conventional and UltraFast Doppler sessions in 126 recipients over a 2-mo period after LT, using an Aixplorer scanner The Doppler indexes of the HA (peak systolic velocity [PSV], end-diastolic velocity [EDV], resistive index [RI] and systolic acceleration time [SAT]) by retrospective analysis of retrieved waves from UltraFast Doppler clips were compared with those obtained by conventional spectral Doppler. Correlation, performance in diagnosing the pathologic wave, examination time and reproducibility were evaluated. The PSV, EDV, RI and SAT of spectral and UltraFast Doppler measurements exhibited excellent correlation with favorable diagnostic performance. During the bedside examination, the mean time spent for UltraFast clip storing was significantly shorter than that for conventional Doppler US measurements. Both conventional and UltraFast Doppler exhibited good to excellent inter-analysis consistency. In conclusion, compared with conventional spectral Doppler, UltraFast Doppler values correlated excellently and yielded acceptable pathologic wave diagnostic performance with reduced examination time at the bedside and excellent reproducibility.
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http://dx.doi.org/10.1016/j.ultrasmedbio.2017.07.018DOI Listing
November 2017

Resection plane-dependent error in computed tomography volumetry of the right hepatic lobe in living liver donors.

Clin Mol Hepatol 2018 03 1;24(1):54-60. Epub 2017 Aug 1.

Division of Hepatobiliary and Liver Transplantation Surgery, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Background/aims: Computed tomography (CT) hepatic volumetry is currently accepted as the most reliable method for preoperative estimation of graft weight in living donor liver transplantation (LDLT). However, several factors can cause inaccuracies in CT volumetry compared to real graft weight. The purpose of this study was to determine the frequency and degree of resection plane-dependent error in CT volumetry of the right hepatic lobe in LDLT.

Methods: Forty-six living liver donors underwent CT before donor surgery and on postoperative day 7. Prospective CT volumetry (V) was measured via the assumptive hepatectomy plane. Retrospective liver volume (V) was measured using the actual plane by comparing preoperative and postoperative CT. Compared with intraoperatively measured weight (W), errors in percentage (%) V and V were evaluated. Plane-dependent error in V was defined as the absolute difference between V and V. % plane-dependent error was defined as follows: |V-V|/W∙100.

Results: Mean V, V, and W were 761.9 mL, 755.0 mL, and 696.9 g. Mean and % errors in V were 73.3 mL and 10.7%. Mean error and % error in V were 64.4 mL and 9.3%. Mean plane-dependent error in V was 32.4 mL. Mean % plane-dependent error was 4.7%. Plane-dependent error in V exceeded 10% of W in approximately 10% of the subjects in our study.

Conclusions: There was approximately 5% plane-dependent error in liver V on CT volumetry. Plane-dependent error in V exceeded 10% of W in approximately 10% of LDLT donors in our study. This error should be considered, especially when CT volumetry is performed by a less experienced operator who is not well acquainted with the donor hepatectomy plane.
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http://dx.doi.org/10.3350/cmh.2017.0023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5875195PMC
March 2018

Measurement of liver volumes by portal vein flow by Doppler ultrasound in living donor liver transplantation.

Clin Transplant 2017 Sep 27;31(9). Epub 2017 Jul 27.

Division of Liver Transplantation and Hepatobiliary Surgery, Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Background: The accurate estimation of liver volume and right/left ratio in donor candidates is critical, but there is no method using portal vein (PV) flow.

Methods: Of 125 donor candidates, right/left liver volume ratio was estimated using ultrasound (US)-PV area ratio and Doppler US-PV flow ratio, and the results were compared with CT volumetry. We analyzed these results in 76 donors who underwent hemihepatectomy. We evaluated diagnostic values of Doppler US-PV flow for <30% remnant liver volume high-risk donors, and compared liver volume by Doppler US-PV flow with actual graft weight.

Results: In 125 donor candidates, 96.8% showed <10% difference between liver volume ratio by Doppler US-PV flow ratio and CT volumetry. Compared with CT volumetry, the mean percentage difference of liver volume ratio by Doppler US-PV flow ratio was significantly smaller than that by US-PV area ratio (±0.7% vs ±6.3%, P<.001). In 76 donors who underwent hemihepatctomy, results were similar, showing smaller mean percentage difference of liver volume ratio by Doppler US-PV flow ratio than that by US-PV area ratio (±1.0% vs ±6.0%, P<.001). Sensitivity and specificity for <30% remnant liver volume donors were 76.9% and 76.8%. Blood-free liver volume by Doppler US-PV flow was linearly correlated with graft weight (R =0.770, P<.001), although significantly different, with 8.5% error ratio (669.3±173.2 vs 633.7±187.1, P=.001).

Conclusion: Doppler US-PV flow can effectively estimate right/left liver volume ratio in initial donor investigation. However, Doppler US-PV flow is not accurate in assessing donors with <30% remnant liver volume and in estimating actual graft weight.
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http://dx.doi.org/10.1111/ctr.13050DOI Listing
September 2017

Impact of high-grade obstruction on outcomes in patients with appendiceal inflammatory masses managed by nonoperative treatment.

Ann Surg Treat Res 2017 Jun 29;92(6):429-435. Epub 2017 May 29.

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.

Purpose: To retrospectively assess the impact of high-grade obstructions identified on initial CT on outcomes of patients with appendiceal inflammatory masses managed by nonoperative treatment.

Methods: Institutional Review Boards approved this retrospective study and informed consent was waived. Included were 52 consecutive patients diagnosed with appendiceal inflammatory masses by CT scan and managed by nonoperative treatment. The main outcome measure was treatment failure and secondary outcomes were complications and initial and total hospital stay. Patient demographics, inflammatory markers, and CT findings for presence of an appendiceal inflammatory mass and high-grade obstruction were assessed. Patients with and without high-grade obstruction were compared for patient characteristics and outcomes using Fisher exact test and Student t-test.

Results: Among 52 patients, 14 (27%) had high-grade obstruction on CT examination at presentation. No significant differences were observed in patient characteristics (P > 0.05), treatment failure (P = 0.33), complications (P = 0.29), or initial (P = 0.73) or total (P = 0.72) hospitalization between patients with and without high-grade obstruction.

Conclusion: For patients who were managed by nonoperative treatment for appendiceal inflammatory masses, the presence of high-grade obstruction identified on initial CT scan did not significantly affect outcomes of treatment failure, complications, and initial and total hospitalization.
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http://dx.doi.org/10.4174/astr.2017.92.6.429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5453876PMC
June 2017

Comparative Analysis of Three Imaging Modalities for Evaluation of Cervical Sagittal Alignment Parameters: A Validity and Reliability Study.

Spine (Phila Pa 1976) 2017 Dec;42(24):1901-1907

Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon, Republic of Korea.

Study Design: This was a radiologic validity and reliability study.

Objective: We aimed to assess the validity and reliability of measurements from standing lateral cervical radiography (XR), reconstructed midsagittal images of supine cervical computerized tomography (CT) scans, and supine magnetic resonance imaging (MRI) for evaluating C2-C7 distance (C27 SVA), C2-C7 Cobb angle (CL), T1 slope (T1S), thoracic inlet angle (TIA), and neck tilt (NT).

Summary Of Background Data: XR is the criterion standard imaging modality for measuring cervical sagittal alignment parameters. However, overlapping bony structures and soft tissue often make the upper end of the manubrium and cervicothoracic junction indiscernible. CT and MRI can overcome this limitation, but their reliability and validity have not been fully elucidated.

Methods: Fifty sets of three examinations from our database have been randomly selected. Three experienced spinal surgeons independently measured C27 SVA, CL, T1S, TIA, and NT. Paired t test and Pearson correlation were used to analyze the validity of CT and MRI in comparison with that of XR. Interobserver and intraobserver reliability were assessed by using the intraclass correlation coefficient (ICC).

Results: The paired t test confirmed the similarities of all CT (except C27 SVA) and MR parameters (except C27 SVA and CL) to the XR parameters (all P > 0.05). All parameters except C27 SVA were correlated (Pearson correlation coefficient, 0.523-0.913). Correlation was highest between CT and MRI and lowest between CT and XR. All three imaging modalities had excellent intraobserver and interobserver reliability (ICC range: 0.770-0.999). Intraobserver and interobserver reliability were highest with MRI and lowest with XR.

Conclusion: CT and especially MRI were more reliable than XR for evaluating cervical sagittal alignment parameters. Considering the reliability and radiation exposure, MRI is a good alternative to XR for measuring cervical sagittal alignment parameters, especially thoracic inlet alignment.

Level Of Evidence: 4.
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http://dx.doi.org/10.1097/BRS.0000000000002256DOI Listing
December 2017

MR cholangiography in potential liver donors: quantitative and qualitative improvement with administration of an oral effervescent agent.

J Magn Reson Imaging 2017 12 23;46(6):1656-1663. Epub 2017 Mar 23.

Division of Liver Transplantation and Hepatobiliary Surgery, and Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Purpose: To determine whether an oral effervescent agent improves magnetic resonance cholangiography (MRC) images, both qualitatively and quantitatively, in potential live liver donors.

Materials And Methods: This retrospective study was approved by the Institutional Review Board, and informed consent was waived. Seventy potential liver donors underwent 2D MRC before and after administration of an oral effervescent agent. One radiologist measured relative contrast ratio (rC) and relative signal intensity (rS) for right and left intrahepatic ducts (RHD and LHD), and common hepatic duct (CHD). After assessment of overall image quality, two other radiologists independently scored visualization of five ductal segments (RHD, LHD, CHD, cystic, and common bile duct) and assessed the preferred image set. In consensus, they assessed the biliary anatomy. The data were analyzed using a paired t-test, Wilcoxon's signed-rank test, and chi-square test.

Results: Both rC and rS of RHD and CHD were significantly higher on MRC images after administration of an oral effervescent agent than before (P < 0.03). The overall image quality grades and biliary visualization scores for all five duct segments were significantly higher on MRC images after administration of an oral effervescent agent than before (P < 0.0001). Between these images, both readers more often preferred MRC images with an effervescent agent rather than those without this agent (reader 1: 56/70, 80.0%; reader 2: 55/70, 78.6%; P = 0.0003). The readers correctly assessed second-order biliary tract anatomy in two more subjects on MRC after administration of an effervescent agent than before.

Conclusion: Oral administration of an effervescent agent improves MRC images, both qualitatively and quantitatively, in live liver donors.

Level Of Evidence: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1656-1663.
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http://dx.doi.org/10.1002/jmri.25715DOI Listing
December 2017

N-butyl-2 cyanoacrylate (NBCA) embolus in the graft portal vein after portosystemic collateral embolization in liver transplantation recipient: what is the clinical significance?

Acta Radiol 2017 Nov 22;58(11):1326-1333. Epub 2017 Feb 22.

3 Division of Liver Transplantation and Hepatobiliary Surgery, Departments of Surgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.

Background An N-butyl-2 cyanoacrylate (NBCA) embolus in the graft portal vein was frequently observed after an intraoperative embolization of portosystemic collaterals performed to prevent portal steal in liver transplant (LT) recipients. The radiological and clinical features of NBCA emboli have not yet been described. Purpose To describe radiological and clinical features of NBCA embolus in graft portal vein after portosystemic collateral embolization in LT recipients. Material and Methods A total of 165 consecutive LT recipients who had undergone intraoperative NBCA embolization of varix were found in single institution's computerized databases of a clinical cohort of LT. Patients were evaluated for NBCA emboli (categorized into major and minor emboli according to location) on first postoperative computed tomography (CT). All electronic medical records and radiologic studies including follow-up was evaluated to determine any radiological and clinical abnormality associated with NBCA embolus. Results NBCA emboli were found in 24% (39/165) of recipients. Although most patients had minor emboli (77%, 30/39) without remarkable ultrasonography (US) abnormalities, seven (78%) of nine recipients with major emboli showed intraluminal echogenic lesions in graft portal vein on grayscale US, and five of them (71%) showed partial portal flow obstruction, although none exhibited any abnormality on contrast-enhanced US. Recipients with NBCA portal emboli showed no significant clinical abnormalities and were discharged safely. NBCA embolus eventually disappeared mostly within six months (82%, 32/39). Conclusion NBCA emboli are frequently observed after portosystemic collateral embolization in LT recipients and are not associated with poor clinical outcome. They may mimic ordinary thromboemboli on US.
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http://dx.doi.org/10.1177/0284185117693460DOI Listing
November 2017

Noninvasive quantitative estimation of hepatic steatosis by ultrasound: a comparison of the hepato-renal index and ultrasound attenuation index.

Med Ultrason 2016 Dec;18(4):431-437

Department of Liver Transplantation Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Aims: To compare the accuracy of the ultrasound attenuation index (USAI) and hepato-renal index (HRI) for the diagnosis of hepatic steatosis (HS).

Material And Methods: Two hundred and twenty-four potential living hepatic donors underwent US and subsequent US-guided liver biopsy. The USAI was calculated from US images with an 8 MHz transducer and HRI was measured on sagittal images with a clear visualization of both the liver and kidney. Using histological degrees of HS as the reference standard, we compared the performance of USAI and HRI for diagnosing HS ≥ 5% and ≥ 30% by receiver operating characteristic curve analysis. The interobserver agreement was evaluated by using intraclass correlation coefficients (ICCs) or Bland-Altman statistics.

Results: Histologic degree of HS was 0-70% (median, 5%). HRI showed a tendency towards higher accuracy than USAI for diagnosing HS ≥ 5% (the area under the ROC curve, 0.856 vs. 0.820; p= 0.279) and ≥ 30% (0.937 vs. 0.909; p = 0.378) without statistical significance. There was an excellent interobserver agreement for both USAI and HRI (ICC = 0.931 and 0.973, respectively). According to the Bland-Altman method, the 95% limits of difference between two readers for HS were -8.5% to 6.6% by USAI and -4.8% to 6.2% by HRI. Most patients would have the difference of calculated HS by USAI (74.0%) and HRI (96.0%) from different operators within a range of ±5%.

Conclusions: Although statistically insignificant, HRI was superior to USAI for the diagnosis and quantitative estimation of HS in terms of diagnostic performance, including accuracy and reproducibility.
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http://dx.doi.org/10.11152/mu-868DOI Listing
December 2016

Progranulin as a predictive factor of response to chemotherapy in advanced biliary tract carcinoma.

Cancer Chemother Pharmacol 2016 Nov 15;78(5):1085-1092. Epub 2016 Oct 15.

Division of Hematology/Oncology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, 29 Saemunan-ro, Jongno-gu, Seoul, 03181, Korea.

Purpose: Progranulin (PGRN), characterized as an autocrine growth and survival factor, is known to stimulate the proliferation and survival of several cancer cell types. However, little is known about the prognostic role of PGRN in advanced biliary tract cancers (BTCs).

Methods: A retrospective analysis was performed on patients with advanced BTC who received palliative chemotherapy between July 2004 and November 2014. PGRN expression was immunohistochemically evaluated according to staining intensity of tumor and peritumoral cells.

Results: A total of 80 patients (39 intrahepatic, 26 extrahepatic, and 18 gallbladder tumors) were analyzed. The median age was 64 years (range 31-79), and 48 patients (60 %) were male. Thirty-five patients (44 %) had high tumor PGRN expression (PGRN positive), and there was a trend of poorer response to chemotherapy in patients with PGRN-positive tumor in terms of overall response rate (7 vs. 18 %). With a median follow-up duration of 17.7 months (range 4.9-35.1), PGRN-positive patients had worse progression-free survival (PFS) with a median of 2.7 months compared to 5.0 months for PGRN-negative patients (P = 0.023). After adjusting for possible confounding factors including sex, age, performance status, disease status, and chemotherapy agent, multivariate analysis showed that PGRN-positive tumor was a prognostic factor independently associated with poor PFS (hazard ratio 1.69, 95 % CI 1.02-2.81; P = 0.044).

Conclusion: PGRN overexpression was significantly associated with poor PFS in advanced BTCs. PGRN expression by IHC analysis might help predict treatment outcomes and provide a new target for molecular therapy.
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http://dx.doi.org/10.1007/s00280-016-3170-zDOI Listing
November 2016

Single-Shot Echo-Planar Diffusion-Weighted MR Imaging at 3T and 1.5T for Differentiation of Benign Vertebral Fracture Edema and Tumor Infiltration.

Korean J Radiol 2016 Sep-Oct;17(5):590-7. Epub 2016 Aug 23.

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul 03181, Korea.

Objective: To compare the apparent diffusion coefficient (ADC) value using single-shot echo-planar imaging sequences at 3T and 1.5T for differentiation of benign fracture edema and tumor infiltration of the vertebral body.

Materials And Methods: A total of 46 spinal examinations were included in the 1.5T MRI group, and a total of 40 spinal examinations were included in the 3T MRI group. The ADC values of the lesion were measured and calculated. The diagnostic performance of the conventional MR image containing sagittal T2-weighted fat saturated image and each diffusion weighted image (DWI) with an ADC value with different b values were evaluated.

Results: The mean ADC value of the benign lesions was higher than that of the malignant lesions on 1.5T and 3T (p < 0.05). The sensitivity of the diagnostic performance was higher with an additional DWI in both 1.5T and 3T, but the sensitivities were similar with the addition of b values of 400 and 1000. The specificities of the diagnostic performances did not show significant differences (p value > 0.05). The diagnostic accuracies were higher when either of the DWIs (b values of 400 and 1000) was added to routine MR image for 1.5T and 3T. Statistical differences between 1.5T and 3T or between b values of 400 and 1000 were not seen.

Conclusion: The ADC values of the benign lesions were significantly higher than those of the malignant lesions on 1.5T and 3T. There was no statistically significant difference in the diagnostic performances when either of the DWIs (b values of 400 and 1000) was added to the routine MR image for 1.5T and 3T.
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http://dx.doi.org/10.3348/kjr.2016.17.5.590DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5007386PMC
August 2017

Usefulness of the quantitative evaluation of diffusion-weighted mri in the diagnosis of anterior cruciate ligament tears.

J Magn Reson Imaging 2016 11 15;44(5):1116-1122. Epub 2016 Apr 15.

Department of Radiology, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital.

Purpose: To evaluate the usefulness of the diffusion-weighted imaging (DWI) in the diagnosis of anterior cruciate ligament (ACL) tear using the contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) values according to the different b values.

Materials And Methods: Institutional review board approval was acquired. We evaluated 74 patients (M:F = 43:31, mean age of 44 years) who underwent 3.0 Tesla knee MR with DWI because of the possibility of ACL tear due to trauma. Region of interest measurements were performed. We (two radiologists) measured the signals of the DWI and derived ADC values on the oblique sagittal DWI with b values of 0, 600, and 1000. The diagnostic accuracies of the conventional MR image and each DWI with an ADC value with a different b value were evaluated. The CNR and ADC values were compared using the Mann-Whitney U-test. The diagnostic performances of the various imaging methods were evaluated using the sensitivity, specificity, and accuracy for differentiating between normal and ACL injury as determined by the use of conventional MRI with additional DWIs with McNemar test. The arthroscopic or clinical findings were used as the reference standard.

Results: The mean CNRs of ligament tears with b values of 600 and 1000 were significantly higher than those of normal ligament (22 versus 7 and 9 versus 4, P value < 0.05). The sensitivities and the accuracies of the DWI were significantly lower than the conventional MRIs (P value < 0.001).

Conclusions: The CNRs of the torn ACL with each b value (600 and 1000) were significantly higher those of than normal ligament, although the ADC values of the torn ligament were not different from normal ligament. Addition of the DWI to the conventional MRI did not improve diagnostic performance. J. Magn. Reson. Imaging 2016;44:1116-1122.
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http://dx.doi.org/10.1002/jmri.25256DOI Listing
November 2016

Discordance between conventional ultrasonography and ElastPQ for assessing hepatic fibrosis in chronic hepatitis B: frequency and independent factors.

J Med Ultrason (2001) 2016 Apr 5;43(2):201-10. Epub 2015 Nov 5.

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.

Purpose: To investigate the frequency of discordance and to identify factors associated with discordance between ultrasonographic and elastographic grades for assessing hepatic fibrosis in Asian patients with chronic hepatitis B.

Methods: Three hundred thirty-four patients with chronic hepatitis B for which both conventional ultrasonography and liver stiffness measurements using elastography were available were included. Patients were graded as 'normal', 'chronic liver disease', or 'liver cirrhosis' by ultrasonography, and as 'no significant fibrosis', 'significant fibrosis', or 'liver cirrhosis' by elastography, and the results of these two modalities were compared. Logistic regression analyses were performed to identify independent factors associated with discordant results.

Results: Of the 334 patients, 153 (45.8 %), 115 (34.4 %), and 66 (19.8 %) patients were 'normal', 'chronic liver disease', and 'liver cirrhosis', respectively, based on the ultrasonographic grades, and 290 (86.8 %), 29 (8.7 %), and 15 (4.5 %) patients were 'no significant fibrosis,' 'significant fibrosis', and 'liver cirrhosis', respectively, based on the elastographic values. Among them, 173 (51.8 %) showed discordance with respect to severity of hepatic fibrosis. In multivariable analysis, discordance was more frequent in patients with ultrasonographic grades of 'chronic liver disease' [adjusted odds ratio (AOR), 1924; P < 0.001] and 'liver cirrhosis' (AOR, 4498; P < 0.001), whereas patients with an elastographic grade of 'liver cirrhosis' showed a negative association with discordance (AOR, 0.002; P = 0.007).

Conclusion: There was a high rate of discordance between hepatic fibrosis grades determined by ultrasonography and elastography. Considering the accuracy of liver stiffness evaluation by elastography, conventional ultrasonography might overestimate hepatic fibrosis in chronic hepatitis B.
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http://dx.doi.org/10.1007/s10396-015-0684-7DOI Listing
April 2016

Focal hepatic solid lesions incidentally detected on initial ultrasonography in 542 asymptomatic patients.

Abdom Radiol (NY) 2016 Feb;41(2):265-72

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, 108 Pyung dong, Jongno-gu, Seoul, 110-746, Korea.

Purpose: The purpose of this study is to evaluate the clinical significance of focal hepatic solid lesions incidentally detected on initial ultrasonography in asymptomatic patients.

Methods: From January 2009 to December 2009, 2670 initial ultrasonographies were performed in asymptomatic population. Of these 2670 initial examinations, 681 focal hepatic solid lesions in 542 patients (mean 39.4 years, range 23-73 years) were detected. Clinical information, ultrasonography features, and the outcome of these lesions were analyzed.

Results: Six hundred and seventy four lesions (99.0%) in 539 patients (99.4%) were benign, while seven lesions (1.0%) in three patients (0.6%) proved to be malignant. Risk factors significantly associated with malignant focal hepatic solid lesions were known history of malignancy, history of hepatitis, a positive result for the hepatitis B surface antigen, and abnormally elevated tumor markers. No malignancy was identified in patients without any one of these four risk factors. Ultrasonographic features of internal heterogeneous echotexture with peripheral hypoechoic rim showed significant associations with malignancy.

Conclusions: Focal hepatic solid lesions incidentally detected on initial ultrasonography were rarely malignant, especially in patients without these risk factors. Therefore, the knowledge of these risk factors and US features is important in order to make a differential diagnosis between benign and malignant focal hepatic lesions.
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http://dx.doi.org/10.1007/s00261-015-0567-9DOI Listing
February 2016

Impact of hypothyroidism on the development of non-alcoholic fatty liver disease: A 4-year retrospective cohort study.

Clin Mol Hepatol 2015 Dec 24;21(4):372-8. Epub 2015 Dec 24.

Department of Gastroenterology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.

Background/aims: Hypothyroidism is reported to contribute to the development of nonalcoholic fatty liver disease (NAFLD). We compared the risk of the development of NAFLD among three groups with different thyroid hormonal statuses (control, subclinical hypothyroidism, and overt hypothyroidism) in a 4-year retrospective cohort of Korean subjects.

Methods: Apparently healthy Korean subjects without NAFLD and aged 20-65 years were recruited (n=18,544) at health checkups performed in 2008. Annual health checkups were applied to the cohort for 4 consecutive years until December 2012. Based on their initial serum-free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels, they were classified into control, subclinical hypothyroidism (TSH >4.2 mIU/L, normal fT4), and overt hypothyroidism (TSH >4.2 mIU/L, fT4 <0.97 ng/dL) groups. NAFLD was diagnosed on the basis of ultrasonography findings.

Results: NAFLD developed in 2,348 of the 18,544 subjects, representing an overall incidence of 12.7%: 12.8%, 11.0%, 12.7% in the control, subclinical hypothyroidism, and overt hypothyroidism groups, respectively. The incidence of NAFLD did not differ significantly with the baseline thyroid hormonal status, even after multivariate adjustment (subclinical hypothyroidism group: hazard ratio [HR]=0.965, 95% confidence interval [CI]=0.814-1.143, P=0.67; overt hypothyroidism group: HR=1.255, 95% CI=0.830-1.899, P=0.28).

Conclusions: Our results suggest that the subclinical and overt types of hypothyroidism are not related to an increased incidence of NAFLD.
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http://dx.doi.org/10.3350/cmh.2015.21.4.372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4712165PMC
December 2015

Multiple cystic lymphangiomas of the spleen: radiologic and histopathologic findings.

J Med Ultrason (2001) 2015 Jul 6;42(3):409-12. Epub 2015 Feb 6.

Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, 108 Pyung dong, Jongno-Gu, Seoul, 110-746, South Korea.

Splenic cyst(s) may be noted as an incidental finding on conventional imaging techniques, or as a result of evaluation of a patient with left upper quadrant pain, left shoulder pain, abdominal enlargement, or splenomegaly. Lymphangioma of the spleen is an extremely rare and benign neoplasm in adults, which is characterized by cystic dilatation of the lymphatic vessels in splenic parenchyma. This report describes a case of multiple splenic lymphangiomas in a 41-year-old female. She underwent abdominal ultrasonography for a health check-up. She had no symptoms, and physical examination did not reveal any abnormalities apart from splenomegaly. Ultrasonography and computed tomography showed multiple variable-sized cysts replacing the normal parenchyma of the spleen. There were wall calcifications in several cysts. The patient underwent laparoscopic splenectomy, and the final diagnosis was multiple lymphangiomas of the spleen.
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http://dx.doi.org/10.1007/s10396-015-0612-xDOI Listing
July 2015