Se Jin Ahn

Seoul National University Hospital, Seoul, Seoul, South Korea

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Publications (4)6.11 Total impact

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    Se Jin Ahn, In-One Kim
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    ABSTRACT: Radiation-induced spinal cord gliomas are extremely rare. Since the first case was reported in 1980, only six additional cases have been reported.; The radiation-induced gliomas were related to the treatment of Hodgkin's lymphoma, thyroid cancer, and medullomyoblastoma, and to multiple chest fluoroscopic examinations in pulmonary tuberculosis patient. We report a case of radiation-induced spinal cord glioblastoma developed in a 17-year-old girl after a 13-year latency period following radiotherapy for nasopharyngeal rhabdomyosarcoma. MRI findings of our case are described.
    Korean journal of radiology: official journal of the Korean Radiological Society 09/2012; 13(5):652-7. · 1.32 Impact Factor
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    ABSTRACT: To evaluate the diagnostic performance of computed tomography (CT) colonography (CTC) reconstructed with different levels of adaptive statistical iterative reconstruction (ASiR, GE Healthcare) and Veo (model-based iterative reconstruction, GE Healthcare) at various tube currents in detection of polyps in porcine colon phantoms. Five porcine colon phantoms with 46 simulated polyps were scanned at different radiation doses (10, 30, and 50 mA s) and were reconstructed using filtered back projection (FBP), ASiR (20%, 40%, and 60%) and Veo. Eleven data sets for each phantom (10-mA s FBP, 10-mA s 20% ASiR, 10-mA s 40% ASiR, 10-mA s 60% ASiR, 10-mA s Veo, 30-mA s FBP, 30-mA s 20% ASiR, 30-mA s 40% ASiR, 30-mA s 60% ASiR, 30-mA s Veo, and 50-mA s FBP) yielded a total of 55 data sets. Polyp detection sensitivity and confidence level of 2 independent observers were evaluated with the McNemar test, the Fisher exact test, and receiver operating characteristic curve analysis. Comparative analyses of overall image quality score, measured image noise, and interpretation time were also performed. Per-polyp detection sensitivities and specificities were highest in 10-mA s Veo, 30-mA s FBP, 30-mA s 60% ASiR, and 50-mA s FBP (sensitivity, 100%; specificity, 100%). The area-under-the-curve values for the overall performance of each data set was also highest (1.000) at 50-mA s FBP, 30-mA s FBP, 30-mA s 60% ASiR, and 10-mA s Veo. Images reconstructed with ASiR showed statistically significant improvement in per-polyp detection sensitivity as the percent level of per-polyp sensitivity increased (10-mA s FBP vs 10-mA s 20% ASiR, P = 0.011; 10-mA s FBP vs 10-mA s 40% ASiR, P = 0.000; 10-mA s FBP vs 10-mA s 60% ASiR, P = 0.000; 10-mA s 20% ASiR vs 40% ASiR, P = 0.034). Overall image quality score was highest at 30-mA s Veo and 50-mA s FBP. The quantitative measurement of the image noise was lowest at 30-mA s Veo and second lowest at 10-mA s Veo. There was a trend of decrease in time required for image interpretation as the percent level of ASiR increased, and ASiR or Veo was used instead of FBP. However, differences from comparative analyses of overall image quality score, measured image noise, and interpretation time did not reach statistical significance. ASiR and Veo showed improved diagnostic performance with excellent sensitivity and specificity with less image noise and good image quality compared with FBP reconstruction of same radiation dose. Our study confirmed feasibility of low-dose CTC with iterative reconstruction as a promising screening tool with excellent diagnostic performance similar to that of the standard-dose CTC with FBP.
    Journal of computer assisted tomography 09/2012; 36(5):596-601. · 1.38 Impact Factor
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    ABSTRACT: A histologic grade in head and neck squamous cell carcinoma (HNSCC) is clinically important because of its association with prognosis. The purpose of this study was to investigate the efficacy of histographic analysis of apparent diffusion coefficient (ADC) maps on the basis of the entire tumor volume in differentiating histologic grades in HNSCC at standard (b = 1000 s/mm(2)) and high (b = 2000 s/mm(2)) b values. Fifty-four patients with HNSCC, including well-differentiated (WD; n = 35), moderately differentiated (MD; n = 13) and poorly differentiated (PD; n = 6) carcinomas, were retrospectively evaluated. ADC maps were obtained at two different b values (1000 and 2000 s/mm(2)) in each patient. Tumors were delineated on each slice of ADC maps, and data were collected to obtain a histogram for the entire tumor volume. Histographic parameters were calculated, including mean, standard deviation, kurtosis, skewness, and the ratio of the kurtosis measured at b values of 1000 and 2000 s/mm(2). These parameters were correlated with histologic grades. There was no significant correlation between tumor grades and histographic parameters obtained from ADC maps at b = 1000 s/mm(2). However, mean ADC at b = 2000 s/mm(2) was significantly higher in WD HNSCC (881 ± 131 × 10(-6) mm(2)/s) than in MD and PD HNSCC (770 ± 163 and 780 ± 158 × 10(-6) mm(2)/s, respectively) (P < .05). Kurtosis ratio was significantly higher in PD HNSCC (115 ± 10%) compared to WD and MD HNSCC (91 ± 21% and 86 ± 26%, respectively) (P < .05). Diagnostic accuracy was 100%, 76.9%, and 65.8% for PD, MD, and WD HNSCC, respectively. Histographic analysis of ADC maps on the basis of the entire tumor volume can be useful in differentiating histologic grades of HNSCC using mean ADC at b = 2000 s/mm(2) and kurtosis ratio.
    Academic radiology 07/2012; 19(10):1233-40. · 2.09 Impact Factor
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    ABSTRACT: To assess the technical success and complication rates of the radiologic placement of central venous ports via the internal jugular vein. We retrospectively reviewed 1254 central venous ports implanted at our institution between August 2002 and October 2009. All procedures were guided by using ultrasound and fluoroscopy. Catheter maintenance days, technical success rates, peri-procedural, as well as early and late complication rates were evaluated based on the interventional radiologic reports and patient medical records. A total of 433386 catheter maintenance days (mean, 350 days; range 0-1165 days) were recorded. The technical success rate was 99.9% and a total of 61 complications occurred (5%), resulting in a post-procedural complication rate of 0.129 of 1000 catheter days. Among them, peri-procedural complications within 24 hours occurred in five patients (0.4%). There were 56 post-procedural complications including 24 (1.9%, 0.055 of 1000 catheter days) early and 32 (2.6%, 0.074 of 1000 catheter days) late complications including, infection (0.6%, 0.018 of 10000 catheter days), thrombotic malfunction (1.4%, 0.040 of 1000 catheter days), nonthrombotic malfunction (0.9%, 0.025 of 1000 catheter days), venous thrombosis (0.5%, 0.014 of 1000 catheter days), as well as wound problems (1.1%, 0.032 of 1000 catheter days). Thirty six CVPs (3%) were removed due to complications. Bloodstream infections and venous thrombosis were the two main adverse events prolonging hospitalization (mean 13 days and 5 days, respectively). Radiologic placement of a central venous port via the internal jugular vein is safe and efficient as evidenced by its high technical success rate and a very low complication rate.
    Korean journal of radiology: official journal of the Korean Radiological Society 05/2012; 13(3):314-23. · 1.32 Impact Factor

Publication Stats

19 Citations
6.11 Total Impact Points


  • 2012
    • Seoul National University Hospital
      • Department of Radiology
      Seoul, Seoul, South Korea
    • Seoul National University
      • College of Medicine
      Seoul, Seoul, South Korea