Kyoung Doo Song

Samsung Medical Center, Sŏul, Seoul, South Korea

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Publications (33)56.55 Total impact

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    ABSTRACT: To investigate the early imaging findings and growth rate of pancreatic ductal adenocarcinoma (PDAC), and to assess whether MR imaging detects early PDAC better than CT.
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    ABSTRACT: To compare the performance of the 15-gauge (G) internally cooled electrode with that of the conventional 17-G internally cooled electrode. A total of 40 (20 for each electrode) and 20 ablation zones (ten for each electrode) were made in extracted bovine livers and in in vivo porcine livers, respectively. Technical parameters, three dimensions [long- (Dl), vertical- (Dv), and short-axis diameter (Ds)], volume, and the circularity (Ds/Dl) of ablation zone were compared. Total delivered energy was higher in the 15-G group than in the 17-G group in both ex vivo and in vivo studies (8.78 ± 1.06 kcal vs 7.70 ± 0.98 kcal, p = 0.033; 11.20 ± 1.13 kcal vs 8.49 ± 0.35 kcal, p = 0.001; respectively). The three dimensions of ablation zone had a tendency to be larger in the 15-G group than in the 17-G group in both studies. The ablation volume was larger in the 15-G group than in the 17-G group in both ex vivo and in vivo studies (29.61 ± 7.10 cm(3) vs 23.86 ± 3.82 cm(3), p = 0.015; 10.26 ± 2.28 cm(3) vs 7.79 ± 1.68 cm(3), p = 0.028; respectively). The circularity of ablation zone was not significantly different in both studies. The size of ablation zone was larger in the 15-G internally cooled electrode than in the 17-G electrode in both ex vivo and in vivo studies. Advances in Knowledge: Radiofrequency ablation of hepatic tumours using 15-G electrode is useful to create larger ablation zone.
    The British journal of radiology 04/2015; DOI:10.1259/bjr.20140497 · 1.53 Impact Factor
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    ABSTRACT: To evaluate the natural course of subcentimeter hypervascular nodules at high risk for developing into hepatocellular carcinomas (SHNHR) using serial magnetic resonance imaging (MRI) in patients with a history of hepatocellular carcinoma (HCC). An SHNHR was defined as a subcentimeter hypervascular nodule having typical imaging findings of HCC on gadoxetic acid-enhanced MRI and diffusion-weighted imaging. We included 39 patients with 46 SHNHRs (mean size ± standard deviation, 6.1 ± 1.6 mm; range, 3.2 - 9.0 mm). Overt HCC was defined as pathology proven HCC or a nodule larger than 1 cm with typical imaging findings of HCC. The cumulative rate and the independent predictive factors for progression to overt HCC were evaluated. The median follow-up period was 139 days (range, 64 - 392 days). The cumulative progression rate to overt HCC at 3, 6, 9, and 12 months was 13.9 %, 61.7 %, 83.2 %, and 89.9 %. The initial size of SHNHR was a significant predictor of progression to overt HCC, with an optimal cut-off value of 5.5 mm. The progression rate of SHNHR to overt HCC within 12 months was high (89.9 %) in patients with history of HCC. The initial size of SHNHR was an important predictor for progression to overt HCC. • Most SHNHRs (89.9 %) progressed to overt HCCs within 12 months. • Initial size was an important predictor for progression to overt HCCs. • The optimal cut-off value for initial nodule size was 5.5 mm.
    European Radiology 03/2015; DOI:10.1007/s00330-015-3680-9 · 4.34 Impact Factor
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    ABSTRACT: Purpose To compare radiofrequency (RF) ablation with nonanatomic resection (NAR) as first-line treatment in patients with a single Barcelona Clinic Liver Cancer (BCLC) stage 0 or A hepatocellular carcinoma (HCC) and to evaluate the long-term outcomes of both therapies. Materials and Methods This retrospective study was approved by the institutional review board. The requirement for informed consent was waived. Data were reviewed from 580 patients with HCCs measuring 3 cm or smaller (BCLC stage 0 or A) who underwent ultrasonographically (US) guided percutaneous RF ablation (n = 438) or NAR (n = 142) as a first-line treatment. Local tumor progression, intrahepatic distant recurrence, disease-free survival, and overall survival rates were analyzed by using propensity score matching to compare therapeutic efficacy. In addition, major complications and length of postoperative hospital stay were compared. Results Before propensity score matching (n = 580), the 5-year cumulative rates of local tumor progression for RF ablation and NAR (20.9% vs 12.7%, respectively; P = .093) and overall survival rates (85.5% vs 90.9%, respectively; P = .194) were comparable, while the 5-year cumulative intrahepatic distant recurrence rates (62.7% vs 36.6%, respectively; P < .001) and disease-free survival rates (31.7% vs 61.1%, respectively; P < .001) in the NAR group were significantly better than those in the RF ablation group. After matching (n = 198), there were no significant differences in therapeutic outcomes between the RF ablation and NAR groups, including 5-year cumulative intrahepatic distant recurrence (47.0% vs 40.2%, respectively; P = .240) and disease-free survival rates (48.9% vs 54.4%, respectively; P = .201). RF ablation was superior to NAR for major complication rates and length of postoperative hospital stay (P < .001). Conclusion In patients with one BCLC stage 0 or A (≤ 3 cm) HCC who received RF ablation or NAR as first-line treatment, there were no significant differences in long-term therapeutic outcomes; however, RF ablation was associated with fewer major complications and a shorter hospital stay after treatment. (©) RSNA, 2015.
    Radiology 02/2015; DOI:10.1148/radiol.15141483 · 6.21 Impact Factor
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    ABSTRACT: The purpose of this study was to investigate the value of enhancement kinetics and ancillary imaging findings on gadoxetic acid–enhanced and diffusion-weighted (DW) MR imaging for diagnosing hepatocellular carcinomas (HCCs) without the typical enhancement pattern on contrast-enhanced multiphasic MDCT in patients with chronic liver disease.
    European Journal of Radiology 01/2015; 84(4). DOI:10.1016/j.ejrad.2014.12.023 · 2.16 Impact Factor
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    ABSTRACT: Purpose To compare the long-term outcomes of repeated hepatic resection and radiofrequency (RF) ablation for recurrent hepatocellular carcinoma (HCC) by using propensity score matching. Materials and Methods This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. Thirty-nine patients who underwent repeated hepatic resection and 178 who underwent RF radiofrequency ablation for recurrent HCC hepatocellular carcinoma (mean tumor size ± standard deviation, 1.8 cm ± 0.7) between November 1994 and December 2012 were included in the study. Patients ranged in age from 24 to 85 years (mean, 54.9 years). Men ranged in age from 25 to 85 years (mean, 54.8 years), and women ranged in age from 24 to 76 years (mean, 55.4 years). A 1:2 repeated hepatic resection group- RF radiofrequency ablation group matching was done by using propensity score matching. The overall survival ( OS overall survival ) and disease-free survival ( DFS disease-free survival ) were compared before and after propensity score matching. Complications were assessed. Results Before matching, OS overall survival rates at 1, 3, 5, and 8 years were 88.8%, 88.8%, 83.9%, and 56.3%, respectively, with repeated hepatic resection and 98.9%, 82.5%, 71.0%, and 58.3% for RF radiofrequency ablation. DFS disease-free survival rates at 1, 3, and 5 years were 66.1%, 48.5%, and 43.1% for repeated hepatic resection and 70.1%, 40.8%, and 30.0% for RF radiofrequency ablation. After matching, the OS overall survival rates at 1, 3, 5, and 8 years were 98.7%, 85.7%, 72.1%, and 68.6%, respectively, and the DFS disease-free survival rates at 1, 3, and 5 years were 71.8%, 45.1%, and 39.4% in the RF radiofrequency ablation group (n = 78). Neither the OS overall survival nor DFS disease-free survival rate was significantly different between the two groups before matching (P = .686 and P = .461) and after matching (P = .834 and P = .960). The postoperative mortality rate was 2.6% in the repeated hepatic resection group and 0% in the RF radiofrequency ablation group. Conclusion The long-term OS overall survival and DFS disease-free survival were not significantly different between repeated hepatic resection and RF radiofrequency ablation for patients with recurrent HCC hepatocellular carcinoma after hepatic resection. © RSNA, 2015.
    Radiology 01/2015; 275(2):141568. DOI:10.1148/radiol.14141568 · 6.21 Impact Factor
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    ABSTRACT: To evaluate the feasibility of half-dose gadoxetic acid (0.0125mmol/kg) for liver MRI at 3-T compared to standard-dose (0.025mmol/kg) in patients at risk for nephrogenic systemic fibrosis (NSF). Forty patients who underwent both half-dose and standard-dose gadoxetic acid-enhanced MRIs were included. Contrast enhancement index (CEI) was calculated for liver, aorta, pancreas and kidney. Two observers independently rated and performed a one-to-one direct comparison of enhancement quality for both groups. Liver CEIs were not significantly different on arterial phase between the two groups but CEIs of standard-dose MRIs were greater than half-dose MRIs on other phases (P<0.001). CEIs were not significantly different on arterial phase for the aorta or on any phases for the pancreas. Kidney CEIs of standard-dose MRIs were greater than half-dose MRIs on all phases (P<0.05). Enhancement quality of both groups was diagnostic and did not significantly differ for any organs. In one-to-one direct comparisons of enhancement quality, equal ratings were given in 87.5% (35/40) of cases by observer 1 and 85.0% (34/40) by observer 2. Liver MRI using half-dose gadoxetic acid at 3-T can be a feasible alternative for standard-dose MRI in patients at risk for NSF. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
    European Journal of Radiology 12/2014; 84(3). DOI:10.1016/j.ejrad.2014.12.010 · 2.16 Impact Factor
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    ABSTRACT: The objective of this study was to compare the targeting and ablation performance between a newly developed radiofrequency (RF) electrode embedded with an electromagnetic position sensor (EMPS) at the electrode tip and a conventional RF electrode.
    Investigative Radiology 10/2014; 50(2). DOI:10.1097/RLI.0000000000000103 · 4.45 Impact Factor
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    ABSTRACT: OBJECTIVE. The purpose of this article is to evaluate the antiangiogenic effects of brivanib using dynamic contrast-enhanced MRI (DCE-MRI) in an orthotopic mouse model of human hepatocellular carcinoma (HCC). MATERIALS AND METHODS. With human HCC (HepG2 cell line) orthotopic nude mouse xenografts, brivanib was administered orally to the treatment group, and the vehicle was administered to the control group for 14 days. DCE-MRI was performed before the start of the therapy and 7 and 14 days after the start of therapy. Treatment-induced changes in tumor volume and microvessel density (MVD) assessed by CD31 immunohistochemistry were analyzed. Perfusion parameters, including volume transfer constant between blood plasma and extravascular extracellular space (K(trans)), fractional extravascular extracellular space per unit volume of tissue (ve), and rate constant between extravascular extracellular space and blood plasma (Kep), were calculated using the two-compartment model. RESULTS. Brivanib shows potent antitumor activity in tumor volume. The mean (± SD) MVD of the tumors was statistically significantly lower in the brivanib-treated group (40.8 ± 17.3 vessels/field) than in the control group (55.2 ± 9.05 vessels/field) (p < 0.05). In the control group, the K(trans) value increased statistically significantly between the baseline and 14 days after treatment (p = 0.048). In the brivanib-treated group, the K(trans) and ve values decreased statistically significantly between baseline and 7 days after treatment (p = 0.024 and p = 0.031, respectively) and between baseline and 14 days after treatment (p = 0.043 and p = 0.018, respectively). The difference between the K(trans) and ve values between baseline and 14 days after treatment showed a statistically significant difference between the two groups (p = 0.004 and p = 0.034, respectively). CONCLUSION. DCE-MRI is feasible in the orthotopic mouse model of human HCC, and it can noninvasively monitor brivanib-induced changes in tumor microvasculature.
    American Journal of Roentgenology 06/2014; 202(6):W559-66. DOI:10.2214/AJR.13.11042 · 2.74 Impact Factor
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    ABSTRACT: To determine the value of fusion imaging with contrast-enhanced ultrasonography (CEUS) and computed tomography (CT)/magnetic resonance (MR) images for percutaneous radiofrequency ablation (RFA) of very-early-stage hepatocellular carcinomas (HCCs) that are inconspicuous on fusion imaging with B-mode ultrasound (US) and CT/MR images. This retrospective study was approved by our institutional review board and the requirement for informed consent was waived. Fusion imaging with CEUS using Sonazoid contrast agent and CT/MR imaging was performed on HCCs (<2 cm) that were inconspicuous on fusion imaging with B-mode US. We evaluated the number of cases that became conspicuous on fusion imaging with CEUS. Percutaneous RFA was performed under the guidance of fusion imaging with CEUS. Technical success and major complication rates were assessed. In total, 30 patients with 30 HCCs (mean, 1.2 cm; range, 0.6-1.7 cm) were included, among which 25 (83.3%) became conspicuous on fusion imaging with CEUS at the time of the planning US and/or RFA procedure. Of those 25 HCCs, RFA was considered feasible for 23 (92.0%), which were thus treated. The technical success and major complication rates were 91.3% (21/23) and 4.3% (1/23), respectively. Fusion imaging with CEUS and CT/MR imaging is highly effective for percutaneous RFA of very-early-stage HCCs inconspicuous on fusion imaging with B-mode US and CT/MR imaging.
    03/2014; 20(1):61-70. DOI:10.3350/cmh.2014.20.1.61
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    ABSTRACT: To evaluate the feasibility of using coronary magnetic resonance angiography (CMRA) with stress-perfusion and delayed-enhancement MRI as a screening tool for the detection of coronary artery disease (CAD) in asymptomatic subjects. Three hundred and forty-one self-referred asymptomatic subjects were enrolled in this study. Cardiac MR imaging was performed using a 1.5-T scanner with a 32-channel cardiac coil. Coronary artery stenosis, regional wall motion abnormalities, myocardial perfusion abnormalities, and delayed myocardial enhancement were analyzed. The occurrence of new chest pain and cardiac events was assessed in 332 subjects (97.3 %) over an average 29 ± 6 months (range, 18-39 months) follow-up period. A total of 3296 (82.4 %) of 4000 coronary artery segments examined exhibited diagnostic image quality on combined whole-heart and volume-targeted CMRA. Combined MRI detected significant CADs in 13 (3.8 %) of 341 subjects. Among these, 11 subjects (84.6 %) had both coronary artery stenosis (≥50 % by diameter) on CMRA and stress-perfusion defects in corresponding areas. Five of the 13 subjects showed evidence of old myocardial infarctions on delayed-enhancement MRI. Three subjects (0.9 %) underwent percutaneous coronary intervention after CAD was detected on cardiac MRI. There were no cardiac events during the follow-up period in subjects who complied with follow-up. Normal stress-perfusion and delayed-enhancement MRI lead to excellent outcomes when used to predict future cardiac events in asymptomatic subjects. Coronary MRA correlates well with stress-perfusion MRI for detecting significant CAD and helps exclude CAD in asymptomatic individuals.
    Journal of Cardiovascular Magnetic Resonance 01/2014; 16(Suppl 1):P231. DOI:10.1186/1532-429X-16-S1-P231 · 5.11 Impact Factor
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    ABSTRACT: To evaluate the incidence and causes of mistargeting after fusion imaging-guided percutaneous radiofrequency (RF) ablation of hepatocellular carcinomas (HCCs). Between September 2011 and March 2013, 955 HCCs in 732 patients were treated with percutaneous RF ablation. Among them, ablation of 551 HCCs was accomplished under fusion imaging guidance, and seven mistargetings were noted in seven patients (male-to-female ratio = 6:1; mean age, 60.1 y; range, 47-73 y). The incidence of mistargeting and the cause of liver disease in the patients with mistargeting were evaluated. The causes of mistargeting were assessed according to the following classification: small size of HCC, subcapsular location, subphrenic location, confusion with pseudolesions, poor conspicuity of HCC, poor sonographic window, and poor electrode path. The incidence of mistargeting after fusion imaging-guided RF ablation was 1.3% (7 of 551). All patients with mistargeting were hepatitis B virus carriers. The most common cause of mistargeting was the small size of HCC (100%; 7 of 7), followed by confusion with surrounding pseudolesions (85.7%; 6 of 7), subcapsular (71.4%; 5 of 7) and subphrenic locations (71.4%; 5 of 7), poor conspicuity of the HCC (71.4%; 6 of 7), poor sonographic window (28.6%; 2 of 7), and poor electrode path (28.6%; 2 of 7). The incidence of mistargeting after fusion imaging-guided RF ablation was 1.3%. The most common cause of mistargeting was the small size of HCC, followed by confusion with surrounding pseudolesions, subcapsular and subphrenic locations, and poor conspicuity of the HCC.
    Journal of vascular and interventional radiology: JVIR 12/2013; 25(2). DOI:10.1016/j.jvir.2013.10.025 · 2.15 Impact Factor
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    ABSTRACT: Hepatocyte specific contrast agents including gadoxetic acid and gadobenate dimeglumine are very useful to diagnose various benign and malignant focal hepatic lesions and even helpful to estimate hepatic functional reservoir. The far delayed phase image referred to as the hepatobiliary phase makes the sensitivity of detection for malignant focal hepatic lesions increased, but specificity of malignant diseases, including hepatocellular carcinoma, metastasis and cholangiocarcinoma, characterization remained to be undetermined.
    12/2013; 19(4):360-366. DOI:10.3350/cmh.2013.19.4.360
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    ABSTRACT: OBJECTIVE. The objective of our study was to assess whether fusion imaging of conventional ultrasound and liver CT or MR images can improve the conspicuity of lesions and feasibility of percutaneous radiofrequency ablation (RFA) for the treatment of hepatocellular carcinomas (HCCs) not visible on ultrasound. Whether peritumoral anatomic landmarks can be used for the placement of an electrode in HCCs not visible on ultrasound even after image fusion was also evaluated. MATERIALS AND METHODS. Planning ultrasound for percutaneous RFA was performed using conventional ultrasound first and then using fusion imaging later during the same session. The visibility of HCCs and feasibility of RFA on conventional ultrasound and on fusion imaging were assessed. We evaluated how many HCCs initially not visible on conventional ultrasound could be visualized and ablated after applying the fusion imaging technique. One hundred twenty HCCs not visible on conventional ultrasound in 96 patients were included. RESULTS. When fusion imaging was applied, 38 of the 120 (31.7%) HCCs that were initially not visible could be seen and RFA was feasible. Among the remaining 82 HCCs still not visible after image fusion, 26 (31.7%) were ablated under the guidance of fusion imaging the technique based on peritumoral anatomic landmarks. Overall, 64 of 120 (53.3%) HCCs (59.4%, 57 of 96 patients) not visible on conventional ultrasound could be ablated under the guidance of the fusion imaging technique. CONCLUSION. Fusion imaging can improve the conspicuity of HCCs and the feasibility of percutaneous RFA of HCCs not visible on conventional ultrasound. Peritumoral anatomic landmarks can be used for electrode placement in HCCs that are still not visible even after image fusion.
    American Journal of Roentgenology 11/2013; 201(5):1141-7. DOI:10.2214/AJR.13.10532 · 2.74 Impact Factor
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    ABSTRACT: Angiogenesis inhibition is an attractive therapeutic strategy in the management of solid tumors. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) are key factors in growth and neovascularization of hepatocellular carcinoma (HCC). Brivanib is a novel, orally available dual tyrosine kinase inhibitor that selectively targets the key angiogenesis receptors VEGF‑R2, FGF‑R1 and FGF‑R2. Recently, high‑resolution magic angle spinning magnetic resonance spectroscopy (HR‑MAS MRS) has provided the opportunity to investigate more detailed metabolic profiles from intact tissue specimens that are correlated with histopathology and is thus, a promising tool for monitoring changes induced by treatment. In the present study, 1H HR‑MAS MRS and immunohistochemistry were used to investigate the antitumor efficacy of brivanib in HCC xenograft models. Tumor growth was significantly suppressed in brivanib‑treated mice compared with the controls and treatment was associated with the inhibition of angiogenesis, increased apoptosis and inhibition of cell proliferation. Furthermore, HR‑MAS techniques showed altered metabolic profiles between the two groups. HR‑MAS spectra demonstrated a significant decrease in choline metabolite levels in the treated groups, concurrent with decreased cell proliferation and increased apoptosis. The results showed that 1H HR‑MAS MRS provides quantitative metabolite information that may be used to analyze the efficacy of brivanib treatment in Hep3B tumor xenografts. Thus, the HR‑MAS MRS technique may be a complementary method to support histopathological results and increase its potential for use in the clinic.
    Molecular Medicine Reports 09/2013; 8(5). DOI:10.3892/mmr.2013.1690 · 1.48 Impact Factor
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    ABSTRACT: PURPOSE: To describe peritoneal manifestations of fascioliasis on CT. MATERIALS AND METHODS: We reviewed CT images in 31 patients with fascioliasis confirmed by enzyme-linked immunosorbent assay (ELISA) (n = 24) or surgery (n = 7). Image analyses were performed to identify hepatic, biliary, and peritoneal abnormalities. RESULTS: Hepatic abnormalities were seen in 28 (90.3 %) of the 31 patients. The most common finding was caves sign, which was present in 25 (80.1 %) patients. Three patients (9.7 %) presented with biliary abnormalities exhibiting dilatation and enhancing wall thickening of the bile duct, wall thickening of the gallbladder, and elongated structures in the bile duct or gallbladder. Peritoneal abnormalities were seen in 14 (45.2 %) of the 31 patients. The most common peritoneal abnormality was mesenteric or omental infiltration, which was seen in 9 (29.0 %) patients. Other peritoneal findings included lymph node enlargement (n = 7), ascites (n = 7), thickening of ligamentum teres (n = 2), and peritoneal mass (n = 2). CONCLUSION: Peritoneal manifestations of fascioliasis are relatively common, and CT findings include mesenteric or omental infiltration, lymph node enlargement, ascites, thickening of the ligamentum teres, and peritoneal masses.
    Abdominal Imaging 02/2013; 38(4). DOI:10.1007/s00261-013-9983-x · 1.73 Impact Factor
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    ABSTRACT: Key Words: Stomach neoplasm; Computed tomography; Peritoneum; Neoplasm metastasis; Ascites. Abbreviations: Advanced Gastric Cancer (AGC); Dry Peritoneal Seeding (DPS); Receiver Operating Characteristic (ROC); Computed Tomography (CT); Multi-Detector CT (MDCT); Area Under the ROC Curve (Az); Area Under the Receiver Operating Characteristic Curve (AUC); American Joint Committee on Cancer (AJCC). Background/Aims: To determine the significant CT findings of dry peritoneal seeding (DPS) in patients with advanced gastric cancer (AGC) and to assess whether radiologists' performance in the detection of DPS can be improved using these significant CT findings. Methodology: Two radiologists reviewed CT images of AGC patients with DPS and without seeding for the presence or absence of various CT findings suggesting peritoneal seeding, in consensus. Significant CT findings for DPS were determined using Fisher's exact test. Two other observers, blinded to the results of the consensus review during the first session but not during the second session, evaluated the presence or absence of DPS independently on a five-point scale. Each observer's performance was evaluated using a pair-wise comparison of the receiver operating characteristic (ROC) curves. Results: Soft tissue nodule or plaque on the peritoneal surface was the only significant CT finding of DPS (p=0.014). The areas under the ROC curves of the two observers were not significantly different between the two review sessions. Conclusions: Soft tissue nodule or plaque on the peritoneal surface was a significant CT finding for the detection of DPS. However, radiologists' performance for the detection of DPS did not improve despite knowledge of this finding.
    Hepato-gastroenterology 10/2012; 59(119):2202-6. DOI:10.5754/hge11001 · 0.91 Impact Factor
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    ABSTRACT: PURPOSE: To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma. MATERIALS AND METHODS: Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis. RESULTS: Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1mm (SD: 2.2mm) and 14.9mm (SD: 3.6mm) in patients with and without optic nerve involvement, respectively (P=0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499-0.879) and 0.653 (95% confidence interval: 0.445-0.861) for observer 1 and observer 2, respectively. CONCLUSION: Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.
    European journal of radiology 09/2012; 81(12). DOI:10.1016/j.ejrad.2012.03.034 · 2.16 Impact Factor
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    ABSTRACT: As diffusion-weighted imaging (DWI) is routinely incorporated into the standard clinical protocol, it is clinically relevant to determine whether DWI after gadoxetic acid is comparable to pre-contrast DWI, with regard to the detection and characterization of focal liver lesions. To compare DWI before and after administration of gadoxetic acid in the detection and characterization of small (≤2.5 cm) focal hepatic lesions. One hundred and fifty-eight patients with 237 focal hepatic lesions (≤2.5 cm) (124 HCCs, 50 metastases, 2 cholangiocarcinomas, 43 hemangiomas, and 18 cysts) were included. DWIs were obtained before and after administration of gadoxetic acid. Non-breath-hold DWI was performed with b values of 0, 100, and 800 s/mm(2). Signal-to-noise ratio (SNR), lesion-liver contrast-to-noise ratio (CNR), and apparent diffusion coefficients (ADCs) of the liver and lesion were calculated. Lesion detection with each DWI was evaluated with alternative free-response receiver-operating characteristic analysis by two observers. The sensitivity of the characterization of focal hepatic lesions as solid (malignancy) or non-solid (benignity) with each DWI was calculated using a five-point confidence scale. Inter-observer agreement regarding lesion detection and characterization was evaluated using kappa statistics. SNRs of the liver on post-contrast DWI were significantly lower than on unenhanced DWI at b = 800 s/mm(2) (P < 0.05). SNRs, CNRs, and ADCs of focal hepatic lesions were not significantly different between two DWIs (P > 0.05). The diagnostic accuracy (Az) for lesion detection and the sensitivity for lesion characterization did not show significant difference between two DWIs (P > 0.05). With regard to the detection and characterization of focal hepatic lesions, the kappa values for two DWIs indicated good and excellent inter-observer agreement, respectively. Gadoxetic acid-enhanced DWI showed comparable diagnostic capability to unenhanced DWI for the detection and characterization of small focal hepatic lesions.
    Acta Radiologica 04/2012; 53(5):485-93. DOI:10.1258/ar.2012.110437 · 1.35 Impact Factor
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    ABSTRACT: The objective of our study was to compare the indirect MR arthrographic findings of patients with adhesive capsulitis and patients without adhesive capsulitis. Indirect MR arthrograms of 35 patients (21 women, 14 men; mean age, 50.1 years) diagnosed with adhesive capsulitis clinically were compared with indirect MR arthrograms of 45 patients (23 women, 22 men; mean age, 48.9 years) without adhesive capsulitis. Joint capsule thickness in the axillary recess and the thicknesses of the enhancing portion of the axillary recess and the rotator interval were, respectively, evaluated on coronal T2-weighted images and coronal and sagittal fat-suppressed enhanced T1-weighted images by two radiologists independently. Reliability was studied using the intraclass correlation coefficient (ICC). Receiver operating characteristic (ROC) curves were compared. Patients with adhesive capsulitis had significantly thickened joint capsules in the axillary recess and a thickened enhancing portion in the axillary recess and in the rotator interval. The difference in the thicknesses of the enhancing portion in the axillary recess and in the rotator interval were significantly greater than the difference in joint capsule thicknesses in the axillary recess between the adhesive capsulitis group and the control group (p < 0.001). Interobserver reliability was good for all three indexes (ICC ≥ 0.80). The area under the ROC curve for the thickness of the joint capsule in the axillary recess and the thicknesses of the enhancing portion of the axillary recess and the rotator interval were 0.797, 0.861, and 0.847, respectively. An abundance of enhancing tissue in the rotator interval and thickening and enhancement of the axillary recess are signs suggestive of adhesive capsulitis on indirect MR arthrography.
    American Journal of Roentgenology 12/2011; 197(6):W1105-9. DOI:10.2214/AJR.10.6099 · 2.74 Impact Factor