http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Na, Dong Gyu,Kim, Eung Yeop,Ryoo, Jae Wook,Lee, Kwang Ho,Roh, Hong Gee,Kim, Sam Soo,Song, In Chan,Chang, Kee-Hyun Radiological Society of North America 2005 Radiology Vol.235 No.3
<P>PURPOSE: To retrospectively evaluate the apparent diffusion coefficient (ADC) on magnetic resonance (MR) images and the perfusion parameters of lesions that show brain swelling without concomitant parenchymal hypoattenuation on computed tomographic (CT) scans. MATERIALS AND METHODS: Review board approval was obtained, and informed consent was waived. A total of 14 patients (seven men and seven women; mean age, 64 years +/- 11) were retrospectively selected from the consecutive 172 patients with acute cerebral ischemia who underwent CT within 6 hours of symptom onset. All patients had brain swelling without parenchymal hypoattenuation, including loss of gray-white matter distinction on CT scans, and they underwent diffusion- and perfusion-weighted MR imaging shortly after CT. CT attenuation, ADC, and perfusion parameters of relative cerebral blood volume (CBV), time to peak (TTP), and relative cerebral blood flow (CBF) were calculated for gray and white matter of the lesion. The measured values were compared with those of the contralateral hemisphere by using the paired t test; comparison of values of perfusion parameters among three subgroups was performed with the Kruskal-Wallis test. Arterial occlusions were determined with MR angiography or conventional angiography. RESULTS: The mean interval between initial CT and MR imaging was 2.4 hours +/- 0.9 (range, 0.4-3.4 hours). The ADC of lesions was similar to that of contralateral normal tissue (mean ADC ratio for gray matter and white matter, 0.99 and 0.97, respectively) (P > .05). Lesions had an increased relative CBV (P < .001), a mild to moderate TTP delay (P < .001), and a variable but not statistically significant reduction of relative CBF. The mean relative CBF of gray matter was less in patients who had complete infarction (0.81 +/- 0.16) than that in patients with partial infarction (0.99 +/- 0.16) or those with a normal radiologic outcome (1.12 +/- 0.22), but this difference was not statistically significant (P > .05). Proximal cerebral artery occlusions were found in all patients. In five (36%) patients, the lesion did not progress to infarction at follow-up. CONCLUSION: The CT sign of brain swelling without concomitant parenchymal hypoattenuation in patients with acute cerebral ischemia does not represent severe ischemic damage and may suggest ischemic penumbral or oligemic tissue.</P>
Kim, Su Jin,Kim, Hyung-Ho,Kim, Young Hoon,Hwang, Sun Hwi,Lee, Hye Seung,Park, Do Joong,Kim, So Yeon,Lee, Kyoung Ho Radiological Society of North America 2009 Radiology Vol.253 No.2
<P>PURPOSE: To retrospectively measure the diagnostic performance of prospective computed tomographic (CT) results obtained by using 16- or 64-detector row scanners in the detection of peritoneal metastases (PMs) in patients with advanced gastric cancer. MATERIALS AND METHODS: The institutional review board approved this retrospective study and waived the need to obtain patient consent. In 498 patients with gastric cancer (stage >or= T2) who were undergoing surgery, the presence of PM was prospectively rated as grade 0 (absent), grade 1 (equivocal), or grade 2 (present) on CT scans (0.67 or 2 mm thick) that were interpreted by interactively adjusting the viewing thickness and viewing plane. The CT readings were retrospectively compared with surgical and pathologic findings. In patients in whom the presence of PM was rated as grade 1 or less, factors predictive of PM were identified by testing variables, including patient and tumor characteristics, with univariate tests and multivariate logistic regression analysis. RESULTS: Fifty-three patients (10.6%) had confirmed PM. When only grade 2 was considered to indicate a positive CT reading, sensitivity and specificity were 28.3% (15 of 53) and 98.9% (440 of 445), respectively. With the threshold of grade 1 or greater indicating a positive reading, sensitivity and specificity were 50.9% (27 of 53) and 96.2% (428 of 445), respectively. In the patients with grades of 1 or less, the significant factors predictive of PM were greater tumor size and T stage. CONCLUSION: The sensitivity of PM detection is limited, even with modern CT techniques. In patients whose CT results are not definitely positive for PM, staging laparoscopy is still recommended if the aforementioned two predictive factors (greater tumor size and T stage) are suspected.</P>
Park, Chang Min,Goo, Jin Mo,Lee, Hyun Ju,Kim, Min A,Kim, Hyo-Cheol,Kim, Kwang Gi,Lee, Chang Hyun,Im, Jung-Gi Radiological Society of North America 2009 Radiology Vol.251 No.3
<P>PURPOSE: To investigate the correlation between first-pass perfusion computed tomographic (CT) indexes and histologic vascular parameters in FN13762 breast cancer in rats by using region-by-region correlation methods. MATERIALS AND METHODS: The Animal Care and Use Committee approved this study. FN13762 murine breast cancer cells were implanted in 14 female Fischer 344 rats, and first-pass perfusion CT was performed. CT perfusion maps depicting blood flow, blood volume, mean transit time (MTT), and permeability-surface area (PSA) product were generated by using commercial perfusion software. The entire tumor area was divided into six separate regions on perfusion maps, and the regional perfusion indexes were quantified. Histologic vascular parameters, including microvessel density (MVD), luminal vessel number, luminal vessel area, and luminal vessel perimeter, were measured in the histologic region corresponding to the perfusion maps. Correlation analysis was performed between regional tumor perfusion indexes and histologic vascular parameters of the corresponding tumor region. Additionally, mean perfusion values of the entire tumor were correlated with histologic vascular parameters of the hot spot within the tumor. Among 14 rats, four were excluded from the analysis, and results were based on a final total of 10 rats. RESULTS: In tumors, blood flow, blood volume, and PSA product were significantly higher and MTT was significantly shorter (P < .05 for all) than these values in normal neck muscles. At region-by-region correlation, regional blood flow (r = 0.476), blood volume (r = 0.348), and MTT (r = -0.506) were significantly correlated with MVD in the corresponding tumor region (P < .01 for all). After adjustment for biologic variability between rats, regional blood flow (r = 0.614), blood volume (r = 0.515), MTT (r = -0.524), and PSA product (r = 0.228) remained significantly correlated with MVD in the corresponding tumor region. Correlation analysis between CT perfusion indexes of the entire tumor and histologic vascular parameters of the hot spot did not show significant correlations (P > .05). CONCLUSION: Regional blood flow, blood volume, and MTT are significantly correlated with MVD in the corresponding tumor region.</P>
Kim, Se Hyung,Lee, Jeong Min,Shin, Cheong-Il,Kim, Hyo Chul,Lee, Joon-Goo,Kim, Jong Hyo,Choi, Jin Young,Eun, Hyo Won,Han, Joon Koo,Lee, Jae Young,Choi, Byung Ihn Radiological Society of North America 2008 Radiology Vol.248 No.2
<P>PURPOSE: To prospectively evaluate the effects of z-axis spatial resolution and tube current on the sensitivity of a commercially available computed tomographic (CT) colonography computer-aided diagnosis (CAD) system for polyp detection by using pig colon phantoms. MATERIALS AND METHODS: Ninety-six polyps were created and analyzed in 14 pig colon phantoms. CT colonography was performed by using a 16-detector CT scanner at 0.75-mm collimation; 10, 50, 100, and 160 mAs; and a pitch of 1.5. At each milliampere-second setting, the CT images were reconstructed with a section thickness (ST) of 1.5 mm and a reconstruction increment (RI) of 1.3 mm. To evaluate the effect of z-axis spatial resolution, CT images were also reconstructed at 100 mAs with various SI and RI combinations (respectively: 1.0 and 0.7 mm, 3.0 and 2.0 mm, 3.0 and 3.0 mm, 5.0 and 5.0 mm). The phantom data were then analyzed by using a CAD program. CAD performance with different CT parameters was calculated and compared in terms of per-polyp sensitivity and number of false-positive (FP) findings per data set. RESULTS: At a constant tube current of 100 mAs, the polyp detection rate was significantly higher in data sets obtained with SI and RI combinations of 1.0 and 0.7 mm, respectively (81% [78/96]), and 1.5 and 1.3 mm, respectively (75% [72/96]), than in those obtained with the three thicker ST-RI settings (27% [26/96] to 64% [61/96]) (P < .01). A similar trend was observed, regardless of polyp size or morphology. However, the number of FP findings at the 1.0 mm and 0.7 mm setting (8.9 per phantom) was also significantly greater than that at the thicker ST-RI settings (4.0-6.1 per phantom) (P < .05). At a constant z-axis spatial resolution (1.5-mm ST, 1.3-mm RI), CAD polyp detection rate and number of FP findings per phantom remained nearly constant-close to 78% (75/96) and 6.1, respectively-at various tube current settings. CONCLUSION: CAD performance in polyp detection at CT colonography is highly dependent on z-axis spatial resolution. However, tube current is not an influencing factor in CAD performance at a given z-axis spatial resolution. Supplemental material: http://radiology.rsnajnls.org/cgi/content/full/2482071025/DC1.</P>
Kim, Hye Jin,Lee, Seung Soo,Byun, Jae Ho,Kim, Jin Cheon,Yu, Chang Sik,Park, Seong Ho,Kim, Ah Young,Ha, Hyun Kwon Radiological Society of North America 2015 Radiology Vol. No.
<P>To prospectively compare diagnostic performance of diffusion-weighted (DW) imaging, gadoxetic acid-enhanced magnetic resonance (MR) imaging, both techniques combined (combined MR imaging), and computed tomography (CT) for detecting colorectal hepatic metastases and evaluate incremental value of MR for patients with potentially curable colorectal hepatic metastases detected with CT.</P>
Kim, Seong Ho,Lee, Jeong Min,Lee, Eun Sun,Baek, Jee Hyun,Kim, Jung Hoon,Han, Joon Koo,Choi, Byung Ihn Radiological Society of North America 2015 Radiology Vol. No.
<P>To evaluate the diagnostic performance of magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP) in determining the malignant potential and surgical resectability of pancreas intraductal papillary mucinous neoplasms (IPMNs).</P>
Xenon ventilation CT with a dual-energy technique of dual-source CT: initial experience.
Chae, Eun Jin,Seo, Joon Beom,Goo, Hyun Woo,Kim, Namkug,Song, Koun-Sik,Lee, Sang Do,Hong, Soo-Jong,Krauss, Bernhard Radiological Society of North America 2008 Radiology Vol.248 No.2
<P>Institutional review board approval and written informed consent were obtained. Although xenon (Xe) ventilation CT has been introduced as a potential method with which to depict regional ventilation, quantification of Xe enhancement has been limited by the variability of lung attenuation caused by different lung volumes between scans. The purpose of this study was to assess the feasibility of Xe ventilation CT with a dual-energy technique. Dual-energy CT was performed in 12 subjects after Xe inhalation. With use of a dual-energy technique, the Xe component could be extracted without any influence from lung volume. Dynamic and static regional ventilation function can be displayed with an exact match to the thin-section CT image.</P>
Yoon, Jeong Hee,Lee, Jeong Min,Suh, Kyung-Suk,Lee, Kwan-Woong,Yi, Nam-Joon,Lee, Kyung Bun,Han, Joon Koo,Choi, Byung Ihn Radiological Society of North America 2015 Radiology Vol. No.
<P>To evaluate the diagnostic performance of magnetic resonance (MR) fat quantification and MR elastography for the assessment of hepatic steatosis and fibrosis in living liver donor candidates.</P>