Young Ho So

Clinical significance of elevated level of serum antithyroglobulin antibody in patients with differentiated thyroid cancer after thyroid ablation

objective This study was designed to investigate whether an elevated serum antithyroglobulin antibody (TgAb) reflects cancer recurrence in thyroglobulin (Tg)‐undetectable patients with differentiated thyroid carcinoma (DTC) after thyroid ablation.

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.

Multiphasic MDCT enhancement pattern of hepatocellular carcinoma smaller than 3 cm in diameter: tumor size and cellular differentiation.

OBJECTIVE The purpose of this study was to evaluate according to size and degree of cellular differentiation the multiphasic MDCT enhancement pattern of hepatocellular carcinoma (HCC) smaller than 3 cm in diameter in patients with cirrhosis. MATERIALS AND METHODS In 155 consecutively registered patients (126 men, 29 women; mean age, 58.4 years), 204 pathologically proven HCCs smaller than 3 cm were detected at multiphasic MDCT. Three radiologists in consensus classified the relative attenuation of the tumors compared with the surrounding liver parenchyma as hyperattenuation, isoattenuation, or hypoattenuation on biphasic (n = 86) and triphasic (n = 69) CT scans. RESULTS The prevalent enhancement patterns of HCC differed depending on tumor size. The prevalent pattern of HCC measuring 20-29 mm was arterial hyperattenuation with venous washout (47%, 47/101). The prevalent enhancement patterns of HCC smaller than 10 mm and HCC measuring 10-19 mm were isoattenuation during the arterial and portal venous phases (29%, 6/21) and hyperattenuation and isoattenuation during the arterial and portal venous phases (33%, 27/82). The typical HCC enhancement pattern (arterial hyperattenuation with venous washout) was identified in 48% (67/141) of the moderately and poorly differentiated HCCs and in 13% (8/63) of well-differentiated HCCs. CONCLUSION The prevalent enhancement patterns of HCC smaller than 3 cm on multiphasic MDCT scans differed depending on tumor size and cellular differentiation. HCCs smaller than 2 cm and well-differentiated HCCs frequently had atypical enhancement patterns.

Effects of Nitroglycerin on the Diagnostic Accuracy of Electrocardiogram-gated Coronary Computed Tomography Angiography

Objectives: To evaluate the effect of nitroglycerin on the diagnostic accuracy of electrocardiogram-gated coronary computed tomography (CT) angiography in patients with suspected coronary artery disease. Methods: Computed tomography angiography was performed on 76 patients using a 16-slice CT scanner. Forty-six patients received a sublingual nitroglycerin 1 minute before CT scanning (the NTG group), but the other 30 did not (the non-NTG group). No statistically significant differences were evident between these 2 groups in terms of clinical and demographic characteristics. Significant stenosis (≥50% diameter reduction) as determined by CT was evaluated according to patient-based and segment-based analyses, and results were compared with conventional coronary angiographic findings. In addition, segments of the coronary artery were reclassified by segment luminal size into proximal, mid, and distal segments, and the diagnostic accuracies of the NTG and non-NTG approaches were evaluated in these segments. Results: Differences in heart rate, and systolic and diastolic blood pressures before and after using nitroglycerin were 1.0 ± 2.4 beats per minute, −8.3 ± 14.4 mm Hg, and −4.6 ± 10.6 mm Hg, respectively. Sensitivity, specificity, and positive and negative predictive values in the NTG group were higher than in the non-NTG group by patient-based analysis (P = 0.25) and by segment-based analysis (P < 0.05). In addition, based on the luminal size of each segment, diagnostic accuracy in the NTG group was significantly higher for proximal segments than in the non-NTG group (96.7% vs 89.7%; P < 0.05). Conclusions: The use of nitroglycerin was found to be safe and to improve the diagnostic accuracy of coronary CT angiography for the evaluation of coronary artery disease.

F-18-fluorodeoxyglucose positron emission tomography as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients with local recurrence in cervical lymph nodes.

F‐18–labeled fluorodeoxyglucose–positron emission tomography (FDG‐PET) has a supplementary role in localizing recurrent sites of differentiated thyroid carcinoma. We evaluated whether FDG‐PET is feasible as a presurgical evaluation modality for I‐131 scan–negative thyroid carcinoma patients.

Follow-up CT Evaluation of the Mural Changes in Active Takayasu Arteritis

Objective We wanted to evaluate the mural changes by CT on the follow-up examination of patients with active Takayasu arteritis. Materials and Methods The study included 18 patients, (4 males and 14 females), with active Takayasu arteritis. A total of 44 CT examinations were done during the follow-up period (mean: 55.6 months). At the time of the last follow-up CT, the disease, on the basis of the erythrocyte sedimentation rate (ESR), was found to be inactive in five patients and the disease was active and persistent in 13 patients. The thickness and CT attenuation of the aortic wall on the precontrast, arterial and venous phases were measured on the initial and the follow-up CT examinations. The ratio of the mural attenuation over that of the back muscle on the initial CT was compared with the ratio found on the follow-up CT. Results The initial CT findings included high density and calcifications of the aortic wall in the precontrast images and a thickened wall with enhancements in the arterial and the venous phases. A low-attenuation ring was demonstrated in the venous phase in 15 patients (83%). On the follow-up evaluation, the mean mural thickness decreased significantly from 4.1 mm to 2.4 mm. The mean mural attenuation ratio in the venous phase decreased significantly from 1.9 to 1.3 (p = 0.001). The low attenuation ring was identified in seven patients (39%) who had only with active, persistent Takayasu arteritis. Conclusion The mural changes demonstrated by the follow-up CT evaluations for the patients with active Takayasu arteritis included a decrease of the mural thickness and enhancement, disappearance of the low-attenuation ring on the venous phase, and an increase of the mural attenuation and calcification on the precontrast phase.

Experimental Study on Acute Ischemic Small Bowel Changes Induced by Superselective Embolization of Superior Mesenteric Artery Branches with N-Butyl Cyanoacrylate

PURPOSE To evaluate the degree of ischemic changes of the small bowel after superselective embolization of superior mesenteric artery (SMA) branches at the vasa recta level with N-butyl cyanoacrylate (NBCA) in dogs. MATERIALS AND METHODS In six dogs, superselective embolization was performed with NBCA in five isolated branches of the SMA at the vasa recta level. All dogs were sacrificed 24 hours after embolization. According to the extent of the NBCA mixtures on radiographs of the specimen, embolized segments were divided into group A (embolization of three or fewer vasa recta) or group B (embolization of four or more vasa recta). Histologic evaluation of the mucosal, submucosal, and muscle layers of the embolized segments was performed by a pathologist. RESULTS In group A (n=15), histologic findings were normal in seven segments (47%). Mild ischemic changes were noted in the mucosal layer in eight segments, the submucosal layer in four segments, and the muscle layer in one segment. In group B (n=15), ischemic changes were noted in the mucosal layer in all 15 segments, the submucosal layer in 14 segments, and the muscle layer in 10 segments. The difference in ischemic damage between groups A and B was statistically significant. CONCLUSIONS Superselective embolization involving three or fewer vasa recta of the SMA was relatively tolerable, and embolization involving four or more vasa recta carried an increased risk of substantial ischemic bowel damage. Further studies are necessary to determine the clinical implications of our findings in human subjects.

Balloon Fenestration of Iatrogenic Celiac Artery Dissection

Iatrogenic dissections of the celiac artery during catheterization are rare complications. Herein a case is reported in which complete occlusion of the celiac artery occurred during transcatheter arterial chemoembolization and was immediately successfully recanalized with balloon fenestration of the intimal flap. Follow-up angiography showed patent celiac and common hepatic arteries with mild focal residual stenosis of the common hepatic artery orifice.

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.

Selective Embolization for Post-Endoscopic Sphincterotomy Bleeding: Technical Aspects and Clinical Efficacy

Objective The objective of this study was to evaluate the technical aspects and clinical efficacy of selective embolization for post-endoscopic sphincterotomy bleeding. Materials and Methods We reviewed the records of 10 patients (3%; M:F = 6:4; mean age, 63.3 years) that underwent selective embolization for post-endoscopic sphincterotomy bleeding among 344 patients who received arteriography for nonvariceal upper gastrointestinal bleeding from 2000 to 2009. We analyzed the endoscopic procedure, onset of bleeding, underlying clinical condition, angiographic findings, interventional procedure, and outcomes in these patients. Results Among the 12 bleeding branches, primary success of hemostasis was achieved in 10 bleeding branches (83%). Secondary success occurred in two additional bleeding branches (100%) after repeated embolization. In 10 patients, post-endoscopic sphincterotomy bleedings were detected during the endoscopic procedure (n = 2, 20%) or later (n = 8, 80%), and the delay was from one to eight days (mean, 2.9 days; ± 2.3). Coagulopathy was observed in three patients. Eight patients had a single bleeding branch, whereas two patients had two branches. On the selective arteriography, bleeding branches originated from the posterior pancreaticoduodenal artery (n = 8, 67%) and anterior pancreaticoduodenal artery (n = 4, 33%), respectively. Superselection was achieved in four branches and the embolization was performed with n-butyl cyanoacrylate. The eight branches were embolized by combined use of coil, n-butyl cyanoacrylate, or Gelfoam. After the last embolization, there was no rebleeding or complication related to embolization. Conclusion Selective embolization is technically feasible and an effective procedure for post-endoscopic sphincterotomy bleeding. In addition, the posterior pancreaticoduodenal artery is the main origin of the causative vessels of post-endoscopic sphincterotomy bleeding.