[과학에게 묻다] 인간은 본디 이타적이다?

유정식 샘터사 2014 월간 샘터 Vol.536 No.-

Prostate Cancer: Added Value of Subtraction Dynamic Imaging in 3T Magnetic Resonance Imaging with a Phased-array Body Coil

유정식,정재준,홍순원,정병하,김주희,김기황 연세대학교의과대학 2008 Yonsei medical journal Vol.49 No.5

Purpose: To determine the added value of dynamic subtraction magnetic resonance (MR) imaging for the localization of prostate cancer. Materials and Methods: We examined 21 consecutive patients who underwent MR imaging in 3T unit with a phased-array body coil and then had radical prostatectomy. After T2-weighted fast spin-echo imaging, we performed a contrast-enhanced dynamic 3D gradient-echo imaging consisting of pre-contrast, 2 successive early-phased (first imaging was started just after the appearance of contrast material in the aortic bifurcation followed by second imaging 35 seconds after the initiation of first imaging) and one 5-minute delayed post-contrast series. Subtraction of pre-contrast images from corresponding post-contrast images of each phase was performed on the console. Results: On ROC analysis, the overall accuracy (Az value) of dynamic imaging combined with subtraction imaging was higher than T2-weighted imaging (p=0.001) or conventional dynamic imaging alone (p =0.074) for localization of cancer foci regardless of their zonal locations. Among pathologically verified 81 lesions, the mean volume of detected lesions with the subtraction images (n=49, 0.69cm³) was smaller than with T2-weighted images (n=14, 1.05cm³) or conventional dynamic images (n=43, 0.71cm³). Conclusion: For localization of small prostate cancer, additional subtraction for the dynamic imaging could be superior to both T2-weighted imaging and un-subtracted dynamic imaging.

[과학에게 묻다] 아이큐는 유전일까, 환경일까?

유정식,이희숙(그림) 샘터사 2014 월간 샘터 Vol.531 No.-

Nonlinear Income Inequality Effect on Software Piracy

유정식,조은주,박종현,홍훈,장종익 경제연구소 2012 한국경제학보 Vol.12 No.2

만성 중이염의 고해상력 CT 진단에 관한 고찰

유정식 대한영상의학회 1990 대한영상의학회지 Vol.26 No.4

Through the pr대perative high-resolution computed tomographic(HRCT) evaluation of the patients with chronic middle ear inflammation, the nature and potential complications of the lesion can be evaluated more accurately than previous imaging modalities. We retrospectively reviewed the HRCT findings of chronic middle ear inflammation in 50 surgically proven cases during recent 2 years. We also compared findings of HRCT and otologic surgery in order to know the diagnostic ability of HRCT about the true nature and extent of soft tissue inflammatory masses within the middle ear and various complications. The results obtained were as follows : 1. HRCT domonstrated the soft tissue inflammatory lesion in the middle ear cavity in all 50 cases. Among theses, 32 cases were confirmed to have cholesteatoma, and 12 cases of granulations tissue including 2 cases of cholestrol granuloma, 3 cases of thickened mucosa and 3 cases of inflammatory exude were verified respectively. 2. Among the 32 ases of cholesteatoma, HRCT showed the ossicular erosion in 87% and other complications in 38% of cases. The types of cholesteatoma can be predicted according to the site and extension of soft tissue mass except in 6 cases. 3. Among the 12 cases of granulation tissue, HRCT also showed the erosion of ossicles in 50% and facial nerve canal in 17%. 4. Pars flaccida type cholesteatomas(21 cases) were most frequently noted in atticoantral area(67%) and pars tensa type(4 cases) in mesotympanum(75%). 5. Incus body and malleus head were the most vulnerable portions of bony erosion in pars flaccida type(10/21). 6. We met some difficulty in differentiation of the soft tissue inflammatory mass in 7 cases. 6 cases of ossicular erosion and 3 cases of other complications were also misinterpreted mainly due to anatomic variations and technical factors of HRCT.

작은 동문맥 단락 : 혈관조영상 간세포암의 감별을 요하는 가성병변

유정식 대한영상의학회 1996 대한영상의학회지 Vol.35 No.6

Purpose : To document the findings of a small arterioportal(AP) shunt on hepatic angiography through thevarious diagnostic modalities, and to determine whether this shunt is related to hepatocelluar carcinoma.Materials and Methods : During the hepatic angiography in 223 patients, a small AP shunt and subsequent focalparenchymal staining more than 1cm in diameter were found in 28 patients. We compared this angiographicabnormality using MR imaging(n=10), CTAP(n=12), iodized-oil CT(n=23), intraoperative ultrasonography(n=5) andfollow-up hepatic angiography(n=11), as well as with conventional ultrasonograp-hy and CT scan. Results :Arterioportal shunts noted on angiographic study matched with perfusion defects noted in CTAP(10/12) and also withthe area of arterial enhancement seen on dynamic CT scan(3\4). In no case was a lesion found on MR and no Lipiodoluptake was seen on CT. There was no evidence of tumor growth around the AP shunts on follow-up angiographies, andno tumor was found during surgery. Conclusion : A small AP shunt was not related to the presence of a tumor. Ifthe hemodynamic changes resulfing from a small AP shunt are understood, confusion can be avoided in theinterpretation of vascular imaging including CTAP and dynamic CT.

자기공명영상 경동맥 문맥조영술을 통한 간세포암의 진단:수술전 검사방법으로서의 의의

유정식,김기황,김은경,정수윤,이호철,조병준,전재윤,이관식,지훈상 대한영상의학회 1996 대한영상의학회지 Vol.35 No.3

Purpose : To evaluate the usefulness of fast magnetic resonance (MR) sequences combined with MR arterialportography in the preoperative assessment of hepatocellular carcinoma. Materials and Methods : Twelve patientssuffering from nodular hepatocellular carcinoma complicated by liver cirrhosis underwent T2-weighted turbo spinecho and T1-weighted multisection FLASH with and without fat-suppression MR imaging during single breath-holdsession in each sequence. MR arterial portography was performed with Gd-DTPA injected through a catheter into thesuperior mesenteric or splenic artery during the T1-weighted FLASH sequence. The pathologic findings of surgicalspecimen or follow-up lipiodol CT findings were compared with the MR imaging. Results : MR arterial portographydepicted 17 of the 19 masses (sensitivity, 89%) and the sensitivity of non-contrast fast MR sequences was 74%(14\19). The sensitivity for combined interpretation of all the above sequences was 89% (17/19). MR arterialportography showed perfusion defects from two cysts, one hemangioma, one inflammatory mass, and innumerable tinyregenerating nodules. Static T1-and T2-weighted imaging clearly differentiated, however, benign lesions and truehepatocellular carcinoma. Conclusion : MR arterial portography combined with other fast MR imaging allows tissuecharacterization as well as high detection rate in the evaluation of hepatocellular carcinoma complicated withcirrhosis.

두 개강내 동정맥 기형의 Stereotactic Radiosurgery 치료효과의 평가를 위한 영상진단: 예비보고

유정식 대한영상의학회 1991 대한영상의학회지 Vol.27 No.6

To evaluate the therapeutic effect of sterotactic radiosurgery(RS) of intracranial arteriovenous malformations(AVMs) and to observe the detailed changes in and around the lesions after this treatment method, we reviewed and compared the angiographic and CT findings of 6 patients examined before and 6 to 19 months after treatment with this high energy photon beam radiotherapy by linear accelerator through the sterotactic method. Four out of 6 patients(67%) with small AVMs(1.0-2.7cm3) showed significant reduction in volume more definitely on the angiograms(8%-48%) than the CT scan images, but both diagnostic modalities were able demonstrate the efficacy of steretactic radiosurgery in the treatment of intracranial AVMs. Angiograms also to demonstrated delayed blood flow and decreased size of major draning veins in 3 patients and a small focal vascular defect in another patient with minimal volume change which were not detected in CT images. Angiography proved to be a more reliable imaging technique than CT for the follow-up of these lesions.

[과학에게 묻다] 보톡스가 행복을 감소시킨다?

유정식 샘터사 2015 월간 샘터 Vol.542 No.-

한국 사회에서 사회적경제는 어떤 의미를 갖는가?

유정식 (재)아이쿱협동조합연구소 2015 생협평론 Vol.- No.21