Yong Hwan Jeon

Gadoxetic Acid–Enhanced MRI Versus Triple-Phase MDCT for the Preoperative Detection of Hepatocellular Carcinoma

OBJECTIVEnWe compared the diagnostic performance of gadoxetic acid-enhanced MRI with that of triple-phase 16-, 40-, and 64-MDCT in the preoperative detection of hepatocellular carcinoma (HCC).nnnSUBJECTS AND METHODSnSixty-two consecutively registered patients (54 men, eight women; age range, 31-67 years) with 83 HCCs underwent triple-phase (arterial, portal venous, equilibrium) CT at 16-, 40-, or 64-MDCT and gadoxetic acid-enhanced 3-T MRI. The diagnosis of HCC was established after surgical resection. Three observers independently and randomly reviewed the MR and CT images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques in the detection of HCC was assessed with alternative free response receiver operating characteristic (ROC) analysis. Sensitivity, positive and negative predictive values, and sensitivity according to tumor size were evaluated.nnnRESULTSnFor each observer, the areas under the ROC curve were 0.971, 0.959, and 0.967 for MRI and 0.947, 0.950, and 0.943 for CT. The differences were not statistically significant between the two techniques for each observer (p > 0.05). The differences in sensitivity and positive and negative predictive values between the two techniques for each observer were not statistically significant (p > 0.05). Among 10 HCCs 1 cm in diameter or smaller, each of the observers detected seven tumors with MRI. With CT, one observer detected five, one observer detected four, and one observer detected three HCCs with no statistically significant difference (p > 0.05).nnnCONCLUSIONnGadoxetic acid-enhanced MRI and triple-phase MDCT have similar diagnostic performance in the preoperative detection of HCC, but MRI may be better than MDCT in the detection of HCC 1 cm in diameter or smaller.

Percutaneous radiofrequency ablation of hepatocellular carcinoma : Effect of histologic grade on therapeutic results

OBJECTIVEnThe purpose of our study was to assess the therapeutic results of radiofrequency ablation of hepatocellular carcinoma (HCC) based on the histologic grades of the tumors.nnnSUBJECTS AND METHODSnBetween April 1999 and December 2003, 95 patients with nodular HCC were treated with percutaneous radiofrequency ablation. All tumors were histologically proven by sonography-guided percutaneous biopsy and were classified as Edmondson-Steiner grade I HCC (n = 38) (mean, 2.3 cm) (group 1), grade II HCC (n = 50) (mean, 2.4 cm) (group 2), or grade III HCC (n = 7) (mean, 2.8 cm) (group 3). All patients underwent contrast-enhanced three-phase helical CT examination before and after radiofrequency ablation. After retrospective review of the medical records and follow-up CT examinations, the rates of technique effectiveness, local tumor progression, cumulative survival, and cancer-free survival using a Kaplan-Meier method were calculated and compared among the groups.nnnRESULTSnTechnique effectiveness rates in groups 1, 2, and 3 were 87% (27/31), 71% (30/42), and 43% (3/7), respectively, with statistical significance (p = 0.032). Local tumor progression rates in groups 1, 2, and 3 were 16% (5/31), 36% (15/42), and 71% (5/7), respectively, with statistical significance (p = 0.013). Five-year cumulative survival rates in groups 1, 2, and 3 were 71%, 44%, and 43%, respectively, with no statistical significance (p > 0.05). Four-year cancer-free survival rates in groups 1, 2, and 3 were 39%, 10%, and 0%, respectively (p < 0.05 for groups 1 vs 2; p > 0.05 for groups 1 vs 3 and groups 2 vs 3).nnnCONCLUSIONnThe histologic grade of HCC is an important factor influencing therapeutic results with survival after radiofrequency ablation.

Long‐term follow up results of intraductal papillary mucinous tumors of pancreas

Background and Aim:u2002 Intraductal papillary mucinous tumor (IPMT) of the pancreas can be divided into three clinically distinct subtypes: main duct type, branch duct type and mixed type. Although it has been reported that the branch duct type IPMT is less invasive than the main duct type IPMT, we experienced a number of branch duct type IPMT having a poor prognosis. In the present study we surveyed the survival and recurrence rates according to the subtypes.

Radiofrequency Ablation of Liver Adjacent to Body of Gallbladder: Histopathologic Changes of Gallbladder Wall in a Pig Model

OBJECTIVEnThe purpose of our study was to evaluate the histopathologic changes of gallbladder wall surrounding radiofrequency ablation zones in pig livers and to assess the risk factors for thermal injury of gallbladder wall in terms of distance of the electrode, electrode direction in relation to the gallbladder wall, and time of sacrifice of the animal.nnnMATERIALS AND METHODSnThe study was performed in 15 pigs using an internally cooled single electrode with a 1-cm electrically active tip under sonographic guidance. Twenty-three hepatic ablation zones abutting the gallbladder were analyzed in three phases on the basis of the distance of the electrode (group A, 0.5 cm; group B, 1.0 cm), electrode direction (perpendicular or parallel), and time of sacrifice (immediate or delayed [7 days after radiofrequency ablation]). We evaluated the gross changes, the depth of thermal injury, and the grade of abnormal microscopic changes in the gallbladder wall. Data analysis was performed on the basis of the Fishers exact test.nnnRESULTSnDiscoloration and perforation were more frequent in group A (60%, 6/10, and 20%, 2/10, respectively) than in group B (25%, 2/8, and 0%, respectively, p > 0.05). Perforation was more frequent in the parallel direction and delayed phase (33.3%, 1/3, and 40%, 2/5, respectively) compared with the perpendicular direction and immediate phase (14.3%, 1/7, and 0%, respectively, p > 0.05). Depth of thermal injury showed a significant difference between group A and group B for full-thickness involvement (53.8%, 7/13, versus 0%, respectively, p < 0.05). Abnormal microscopic changes showed that parallel direction and immediate phase were more frequent with full-thickness involvement (71.4%, 5/7, and 71.4%, 5/7, respectively) compared with perpendicular direction and delayed phase (33.3%, 2/6, and 33.3%, 2/6, respectively, p > 0.05).nnnCONCLUSIONnHepatic radiofrequency ablation abutting the gallbladder can produce substantial thermal injury of the gallbladder wall, including perforation, especially when performed without a safe distance.

Depiction of Viable Tumor in Hepatocellular Carcinoma Treated with Transarterial Chemoembolization: Multiphasic Helical CT with Review of the Previous Serial CT Images

Objective The purpose of our study was to assess whether a review of multiphasic helical CT combined with the previous serial CT images could be helpful to depict a viable tumor in hepatocellular carcinoma treated with transarterial chemoembolization. Materials and Methods Twenty-four consecutive patients with 35 hepatocellular carcinomas underwent transarterial chemoembolization followed by hepatic resection. First, three radiologists independently analyzed the last CT images taken before resection for the presence of viable tumor. A second analysis was then performed using the last CT combined with the previous serial CT images. The CT analyses were then compared with the pathologic results. The added value of the review of the previous serial CT images was evaluated by performing a receiver operating characteristic analysis. The sensitivity, specificity and diagnostic accuracy for the depiction of viable tumor were also assessed, and the characteristics of the false-negative lesions were pathologically evaluated. Results The mean diagnostic accuracies (Az values) for the depiction of viable tumor with using the last CT alone and with the review of the previous serial CT images for all observers were 0.885 and 0.901, respectively, which were not significantly difference (p > 0.05). However, the additional review of the previous serial CT images allowed the observers to render a correct diagnosis for three lesions that had been incorrectly diagnosed with the review of last CT alone. The sensitivity, specificity and diagnostic accuracy of the last CT along with the review of the previous serial CT images were 78%, 97% and 84%, respectively. All of the 16 false-negative lesions diagnosed by each observer showed 90% or greater necrosis on the pathologic examination. Conclusion For the depiction of viable tumor in hepatocellular carcinoma treated with transarterial chemoembolization, although the difference in the diagnostic accuracies was not statistically significant, a review of the multiphasic helical CT combined with the previous serial CT images could help reach a correct diagnosis for those lesions incorrectly diagnosed with the review of the last CT alone.

Changes in Sonographic Findings after Treatment of Patients with Clonorchiasis in a Heavy Endemic Area

We measured changes in sonographic findings of patients with clonorchiasis after a treatment in a highly endemic area. A total of 347 residents showed positive stool results for Clonorchis sinensis eggs in a village in northeastern China, and were treated with praziquantel. Of them, 132 patients underwent abdominal sonography both before and 1 year after treatment, and the changes in sonographic findings of 83 cured subjects were compared. Diffuse dilatation of intrahepatic bile ducts (DDIHD) was found in 82 patients (98.2%) before and 80 (96.4%) after treatment, which was improved in 3, aggravated in 1, and unchanged in 79 patients. Increased periductal echogenicity (IPDE) was observed in 42 patients (50.6%) before and 45 (54.2%) after treatment, which was improved in 5, aggravated in 8, and unchanged in 70 patients. Floating echogenic foci in the gallbladder (FEFGB) was detected in 32 patients (38.6%) before and 17 (20.5%) after treatment, which was improved in 20, aggravated in 5, and unchanged in 58 patients. Improvement of FEFGB only was statistically significantly (P = 0.004). The present results confirm that DDIHD and IPDE persist but FEFGB decreases significantly at 1 year after treatment. In a heavy endemic area, the sonographic finding of FEFGB may suggest active clonorchiasis 1 year after treatment.

Image-Guided Transvaginal Drainage of Pelvic Abscesses and Fluid Collection Using a Modified Seldinger Technique

Background: Transvaginal drainage using the trocar method is advantageous as a single-step procedure; however, the procedure may occasionally be difficult to perform, due to buckling of the catheter in the elastic vaginal tissues, despite the presence of a stiff stylet. Purpose: To evaluate the efficacy and the safety of image-guided transvaginal drainage of pelvic abscesses and fluid collection using a modified Seldinger technique. Material and Methods: Fifteen patients (mean age 43 years, range 24–82 years) who underwent transvaginal aspiration (n=1) or catheter drainage (n=14) guided by ultrasound and fluoroscopy were enrolled in this retrospective study. A small coronal incision was performed to facilitate puncture using an 18G needle, tract dilatation, and the insertion of a drainage catheter by the Seldinger technique. Outcome was analyzed with respect to clinical success, technical success, and procedure-related complications. Results: The overall clinical success rate was 87% (13/15 cases). The success rate of catheter drainage was 86% (12/14 cases), and the use of aspiration alone was successful in one patient. Technical success was achieved in all patients, without procedure-related complications. Conclusion: Image-guided transvaginal drainage with a modified Seldinger technique can be a safe and effective alternative treatment for pelvic abscesses and fluid collection.

Usefulness of Screening Ultrasound for Thyroid Gland

Purpose: The purpose of this study was to investigate the usefulness of the ultrasonography as a screening test for thyroid diseases. Materials and Methods: For 7 months, thyroid ultrasonography (7.5 MHz linear array) was performed prospectively by radiologists on 1,316 subjects who do not have a history of the thyroid disease. We analyzed the morphological abnormalities of thyroid gland and these were classified as the nodulal, cystic and diffuse types in accordance with the gender and ages of the patients. We performed ultrasound-guided fine needle aspiration in 21 patients who had sonographic features that were suggestive of malignant thyroid nodules. Physical examination was performed for all subjects by clinicians before the thyroid ultrasonography, and we compared the detectability of thyroid lesions between ultrasonography and physical examination. Results: Thyroidal abnormalities were detected in 94 (7.1%) of 1,316 subjects. Among the 94 patients, 72 (5.5%) showed as nodules, 18 (1.4%) showed as cysts and 4 (0.3%) showed as diffuse abnormalities. The result of the ultrasound-guided aspiration on 21 patient showed 4 malignant nodules, 16 benign nodules and 1 undetermined nodule. Physical examination detected abnormalities in only 12 patients (12.8%) of the 94 patients, which were showed as nodules, cysts and the diffuse type by ultrasonography. Conclusion: Thyroid disease of the general population was relatively common and the detection rate with performing physical examination for the thyroid nodule, cyst and the diffuse type was lower than that for ultrasonography. Thyroid ultrasonography is a useful screening modality for detecting thyroid diseases.