Ung Bae Jeon

Celiac Axis and Common Hepatic Artery Variations in 5002 Patients: Systematic Analysis with Spiral CT and DSA

PURPOSE To identify and evaluate the spectrum and prevalence of celiac axis (CA) and common hepatic artery (CHA) variations by using spiral computed tomography (CT) and digital subtraction angiography (DSA). MATERIALS AND METHODS Institutional review board approval was obtained, and the requirement for informed patient consent was waived. The findings in 5002 patients who underwent spiral CT and DSA were retrospectively evaluated. CHA was defined as an arterial trunk containing at least one segmental hepatic artery and the gastroduodenal artery. The pattern of the aortic origin of the branches of the CA and superior mesenteric arteries was analyzed. The CHA anatomy was then investigated. RESULTS Of 15 possible types of CA variation, 13 types were identified. A normal CA was noted in 4457 (89.1%) of the 5002 patients. Twelve types of CA variation were identified in 482 (9.64%) patients. In the remaining 63 (1.26%) patients, the CA anatomy was classified as ambiguous because the CHA was absent owing to separate origins of the hepatic arteries and the gastroduodenal artery (n = 55) or because the origin of the CHA could not be determined owing to persistent anastomotic channels (n = 8). Seven CHAs originating from the normal CA had a retroportal (n = 6) or transpancreatic (n = 1) course. All eight CHAs originating from the left gastric artery passed the fissure of the ligamentum venosum. The 148 CHAs originating from the superior mesenteric artery showed diverse relationships with the pancreas--being supra-, trans-, or infrapancreatic--and the superior mesenteric-portal venous axis--being pre- or retroportal. The 20 CHAs originating from the aorta had a normal suprapancreatic preportal course. CONCLUSION Known or newly found CA and CHA variations could be systematically described in detail. The authors propose a hypothetical anatomic model for summarizing the observed CHA variations.

May-Thurner Syndrome Complicated by Acute Iliofemoral Vein Thrombosis: Helical CT Venography for Evaluation of Long-Term Stent Patency and Changes in the Iliac Vein

OBJECTIVE The purpose of this study was to use CT venography to evaluate long-term patency and changes in the iliac veins after stent placement for acute iliofemoral vein thrombosis due to May-Thurner syndrome. MATERIALS AND METHODS From December 1999 to July 2007, 30 patients (22 women, eight men; age range, 30-78 years; mean, 56.7 years) with acute iliofemoral vein thrombosis due to May-Thurner syndrome diagnosed with CT venography were treated with catheter-directed thrombolysis and stent placement. The patients underwent follow-up CT venography at variable intervals according to clinician discretion. The primary objective was to determine the primary patency of the stented segment. The secondary objective was to investigate the potential role of CT venography by analyzing the morphologic features and interval changes in stented iliac veins. Cumulative primary and secondary stent patency rates were calculated by Kaplan-Meier estimation. RESULTS Four stent occlusions and one stent collapse were found at the first follow-up CT venographic examination within 1 year (mean duration, 129.3 days) after treatment. One stent occlusion and one stent collapse were managed successfully. The primary and secondary patency rates were 83.3% and 90% 1 and 5 years after treatment. The morphologic features of the common iliac vein did not affect stent patency or expanded stent diameter. During sequential CT venographic follow-up, no new in-stent stenosis or occlusion was found. CONCLUSION Iliac stents placed for May-Thurner syndrome with acute thrombosis had excellent long-term patency. Restenosis or occlusion occurred early, and initial luminal patency was well maintained during long-term follow-up.

Computed tomographic features of pulmonary septic emboli: comparison of causative microorganisms.

Objective: To describe and compare the computed tomographic (CT) findings of pulmonary septic emboli in causative microorganisms. Methods: The CT findings of 16 patients (8 men and 8 women; age range, 17 to 80 years; mean, 53.1 years) with documented pulmonary septic emboli were retrospectively reviewed by 2 radiologists; their decisions on the findings were reached by consensus. Statistical analysis was performed using the t test and the &khgr;2 test. Results: A total of 197 peripheral nodules were seen in 6 gram-positive (n = 88) and 10 gram-negative (n = 109) septic pulmonary emboli patients, respectively. The sizes of the nodules (15.94 mm; range, 3-46 mm) in gram-positive septic emboli were larger than those (12.29 mm; range, 4-44 mm) in gram-negative septic emboli (P = 0.006). Cavitation (n = 30 [34%] vs n = 23 [21%]; P = 0.041) and air bronchogram (n = 12 [14%] vs n = 4 [4%]; P = 0.008) within the nodules were more commonly seen in gram-positive septic emboli. A ground-glass attenuation halo around a nodule (n = 69 [63%] vs n = 32 [36%]; P = 0.000) and feeding vessel signs (n = 56 [51%] vs n = 25 [28%]; P = 0.001) were more commonly seen in gram-negative septic emboli. Wedge-shaped peripheral lesions abutting the pleura were seen in 4 gram-positive (67%) and in 1 gram-negative (10%) septic emboli patients, respectively (P = 0.047). Conclusions: The detailed CT characteristics of peripheral nodules in pulmonary septic emboli may be able to differentiate the causative microorganisms and to provide additional information regarding treatment plans in patients with sepsis.

Extrahepatic Collateral Artery Supply to the Tumor Thrombi of Hepatocellular Carcinoma Invading Inferior Vena Cava: The Prevalence and Determinant Factors

PURPOSE To retrospectively evaluate the prevalence of extrahepatic collateral artery supply to tumor thrombi of hepatocellular carcinomas (HCCs) invading the inferior vena cava (IVC) and to assess the determining factors. MATERIALS AND METHODS From February 1998 to June 2007, 82 patients with IVC tumor thrombi on computed tomography (CT) underwent angiographic evaluation of their extrahepatic collateral artery supply. Potential determining factors for extrahepatic collateral artery supply to the IVC tumor thrombi included sex, age, Child-Pugh class, history of chemoembolization, tumor factors (ie, size, number, and growth pattern), distance from primary tumor to IVC thrombi, portal vein invasion, and extent of IVC thrombi (ie, occupying more than half the IVC lumen on transverse CT image, completely filling and distending IVC lumen, or extending into the right atrium). Univariate analysis and multiple logistic regression analysis were performed. RESULTS Fifty-four of the 82 patients (65.9%) had extrahepatic collateral artery supply: 47 from the right inferior phrenic artery, four from the right adrenal artery, two from the right internal mammary artery, and one from the right renal artery. The presence of extrahepatic collateral artery supply to IVC tumor thrombi showed a significant relationship with a history of chemoembolization (P = .001, odds ratio [OR] = 22.4) and distension of IVC by tumor thrombi (P = .005, OR = 9.1). CONCLUSIONS IVC tumor thrombi of HCCs are frequently supplied by extrahepatic collateral arteries, the most common of which is the right inferior phrenic artery. The significant determining factors are a history of chemoembolization and the extent of IVC tumor thrombi.

Identification of Bleeding Sites in Patients With Postpartum Hemorrhage: MDCT Compared With Angiography

OBJECTIVE This study was designed to evaluate retrospectively the accuracy of MDCT in the identification of bleeding sites in patients with postpartum hemorrhage. MATERIALS AND METHODS Twenty-seven consecutively registered patients (mean age, 31.4 years; age range, 24-39 years) with postpartum hemorrhage underwent contrast-enhanced MDCT before embolization. CT images were reviewed independently by two radiologists who were blinded to the angiographic findings. Disagreements were resolved by consensus. The MDCT diagnosis of active bleeding was made when extravasation of contrast material was identified on contrast-enhanced CT scans. The location of bleeding was classified according to four anatomic regions: uterine body, cervix, vagina, and paragenital area. Each bleeding location was recorded on the right and left sides. Conventional angiography was used as the reference standard. The sensitivity, specificity, and accuracy of MDCT in the detection of hemorrhage were assessed. We also assessed the presence of additional CT abnormalities that might influence further treatment. RESULTS Extravasation of contrast material was depicted on MDCT scans in 24 of 27 patients. The overall location-based sensitivity, specificity, and accuracy of MDCT in the detection of bleeding were 100% (38/38), 96% (171/178), and 97% (209/216). Additional abnormalities detected on CT images included rectus sheath hematoma with contrast extravasation (n = 5), extraperitoneal hematoma (n = 6), gestational pancreatitis (n = 2), diffuse liver disease (n = 2), and abdominal compartment syndrome (n = 1). CONCLUSION MDCT may have a role in the detection and localization of postpartum hemorrhage and yield supplementary information on extrauterine abnormalities.

Early Infectious Complications of Percutaneous Metallic Stent Insertion for Malignant Biliary Obstruction

OBJECTIVE This study was designed to evaluate predisposing factors for early infectious complications after percutaneous metallic biliary stent insertion in patients with malignant biliary obstruction. MATERIALS AND METHODS From August 1999 to June 2008, 215 consecutively registered patients with inoperable malignant biliary obstruction were treated with percutaneous placement of a metallic stent. The incidence of early infectious complications was evaluated. Sex, age, level of obstruction, type and number of stents, and stent position (across or above the main duodenal papilla) were retrospectively reviewed. The findings in patients with early infectious complications were compared with those in patients without early infectious complications. RESULTS Infectious complications occurred within 30 days after stent placement in 14 of 215 (6.5%) patients. Univariate analysis showed a significant difference between the two groups with respect to nontranspapillary stent placement (p=0.003). In the multiple logistic regression analysis, age, sex, level of obstruction, and type and number of stents were negatively associated with the development of early infectious complications (p>0.05). CONCLUSION Our study data showed that stent placement across the main duodenal papilla seemed to prevent early infectious complications after percutaneous metallic biliary stent insertion in patients with malignant biliary obstruction.

Extraforaminal With or Without Foraminal Disk Herniation: Reliable MRI Findings

OBJECTIVE The purpose of our study was to evaluate spinal MR images for extraforaminal disk herniation with or without foraminal disk herniation to determine the reliable MRI findings. MATERIALS AND METHODS Thirty-five patients with extraforaminal with or without foraminal disk herniation confirmed at radiculography or surgery between March 2005 and July 2007 underwent spinal MRI. We assessed the morphologic features of the disk, changes in nerve root thickness, epidural fat obliteration surrounding the nerve root, and displacement of the nerve root in the foraminal and extraforaminal zones. RESULTS Mixed disk herniation was found in 23 patients, and purely extraforaminal herniation was found in 12 patients. Focal eccentricity of the disk contour was identified in 32 patients (91%). Change in the nerve root thickness was found in 30 patients (86%). The nerve roots were displaced in 22 patients (63%), and the original location was maintained in nine patients (26%). Differentiation between the disk and the nerve root was poor in four of the 35 patients (11%). Obliteration of the epidural fat surrounding the nerve root was present in all patients. CONCLUSION The presence of extraforaminal with or without foraminal disk herniation should be ascertained on the basis of the following MRI findings: focal eccentricity of the disk contour, obliteration of epidural fat surrounding the nerve root, change in the thickness of the nerve root, and displacement of the nerve root.

Eu, Gd-Codoped Yttria Nanoprobes for Optical and T1-Weighted Magnetic Resonance Imaging

Nanoprobes with multimodal functionality have attracted significant interest recently because of their potential applications in nanomedicine. This paper reports the successful development of lanthanide-doped Y2O3 nanoprobes for potential applications in optical and magnetic resonance (MR) imaging. The morphology, structural, and optical properties of these nanoprobes were characterized by transmission electron microscope (TEM), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and photoluminescence (PL). The cytotoxicity test showed that the prepared lanthanide-doped Y2O3 nanoprobes have good biocompatibility. The obvious contrast enhancement in the T1-weighted MR images suggested that these nanoprobes can be used as a positive contrast agent in MRI. In addition, the clear fluorescence images of the L-929 cells incubated with the nanoprobes highlight their potential for optical imaging. Overall, these results suggest that prepared lanthanide-doped Y2O3 nanoprobes can be used for simultaneous optical and MR imaging.

Usefulness of Percutaneous Transhepatic Cholangioscopic Lithotomy for Removal of Difficult Common Bile Duct Stones

Background/Aims Approximately 5% to 10% of common bile duct (CBD) stones are difficult to remove by conventional endoscopic methods. Percutaneous transhepatic cholangioscopic lithotomy (PTCSL) can be an alternative method for this condition, but is not well established yet. The aim of this study was to evaluate the clinical efficacy and safety of PTCSL for removal of difficult CBD stones. Methods This study is a retrospective review of 34 consecutive patients who underwent unsuccessful removal of CBD stones using conventional endoscopic methods between December 2008 and July 2010 and were subsequently treated using PTCSL. Results Among 443 patients with CBD stones, 34 patients (7.8%) failed to achieve stone removal using conventional endoscopic methods. Of these 34 patients, 33 were treated using PTCSL. In all 33 cases (100%), complete stone removal was achieved using PTCSL. Most complications (15/17, 88.2%) were mild and transient. Major complications occurred in two patients (6.1%) who experienced hemobilia, and percutaneous transhepatic biliary drainage tract disruption, respectively; which were fully recovered without mortality. Conclusions Despite prolonged hospital stay and temporary decline of quality of life, PTCSL is an effective and safe method in the management of difficult CBD stones, especially in patients with difficulty in approaching the affected bile duct.

Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose.

Background Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and-shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3 ± 6.8) and retrospective CCTA with TCM (77, mean HR: 59.1 ± 9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results There was good agreement for quality scores of coronary artery segment images between the independent reviewers (κ = 0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P > .05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94 ± 0.70 mSv) than for retrospective CCTA with TCM (4.51 ± 1.18 mSv) (P < 0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI] ≥ 25) and non-obese patients (BMI < 25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion Both step-and-shoot and retrospective CCTA with TCM using 128-slice MDCT had similar subjective image quality scores, but step-and-shoot required a lower radiation dose than retrospective CCTA with TCM.