Biomedical subjects

Dongil Choi

Publications and source records attributed to Dongil Choi.

At least 37 records · Page 2Linked to original sources

PubMed2005

Liver abscess after percutaneous radiofrequency ablation for hepatocellular carcinomas: frequency and risk factors.

OBJECTIVE: The purpose of this study was to clarify the frequency and risk factors of liver abscess formation after percutaneous radiofrequency ablation in patients with hepatocellular carcinoma. MATERIALS AND METHODS: Over a 4-year period, 603 patients with 831 hepatocellular carcinomas measuring 5 cm or less in maximum diameter who underwent a total of 751 percutaneous radiofrequency ablation procedures were enrolled in this study. We retrospectively reviewed the medical records and analyzed the overall frequency of liver abscess, risk factors for abscess, and clinical features of the patients. The relationships between liver abscess and potential risk factors were analyzed using either generalized estimating equations or multiple logistic regression analysis. RESULTS: Liver abscess developed in 14 tumors of 13 patients after 13 (13/751 [1.7%]) ablation procedures. Generalized estimating equations and multiple logistic regression analysis of various potential risk factors revealed that preexisting biliary abnormality prone to ascending biliary infection (p = 0.0088), tumor with retention of iodized oil from previous transcatheter arterial chemoembolization (p = 0.040), and treatment with an internally cooled electrode system (p = 0.016) were associated with a significant risk of liver abscess formation. No patient died of liver abscess, and all successfully recovered from liver abscess with parenteral antibiotics and percutaneous clearance of pus. CONCLUSION: Although liver abscess formation was infrequent in patients who underwent percutaneous radiofrequency ablation for hepatocellular carcinoma, the patients with significant risk factors-preexisting biliary abnormality prone to ascending biliary infection, tumor with retention of iodized oil, and treatment with an internally cooled electrode system-for liver abscess formation should be closely monitored after treatment.

Anesthesia, Local↗

PubMed2005

Needle tract implantation after sonographically guided percutaneous biopsy of hepatocellular carcinoma: evaluation of doubling time, frequency, and features on CT.

OBJECTIVE: The purpose of this study was to evaluate the doubling time, frequency, and features on dynamic CT of extrahepatic needle tract implantation of malignant neoplasms after sonographically guided percutaneous biopsy for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Between January 1997 and June 2003, 1,055 patients underwent sonographically guided percutaneous biopsy for HCC. The serial changes of implanted tumor volume were estimated on retrospective review of CT, and their doubling times were calculated from the two CT scans showing the first and last visible implanted tumors. The frequency of extrahepatic needle tract implantation of malignant neoplasms was evaluated overall and according to the type of needle used. The CT features of the implanted tumors were examined with regard to size, number, location, morphology, and enhancement pattern. RESULTS: The mean doubling time of extrahepatic needle tract implantation of malignant neoplasms after sonographically guided percutaneous biopsy was 112 days (range, 22-415 days). The mean time interval between biopsy and the emergence of the implanted tumor on CT was 267 days (range, 116-619 days). The overall frequency was 0.76% (8/1,055). The frequencies according to the type of needle were 1.3% (8/622) for the group treated with the end-cutting needle and 0% (0/433) for the group treated with the tru-cut needle; these frequencies differ from each other with statistical significance (p < 0.05, Fisher's exact test). Fifteen of the 17 implanted tumors were round or oval enhancing nodules along the needle tract, and 13 showed persistent enhancement on equilibrium phase images. CONCLUSION: The doubling times of extrahepatic needle tract implantation of malignant neoplasms after sonographically guided percutaneous biopsy for HCC were similar to those of typical HCCs in the liver on CT-based analysis. The frequency was relatively low, and their CT features were similar to those reported previously.

Abdominal Neoplasms↗

PubMed2005

[Radiological intervention of hepatocellular carcinoma].

In spite of the nice screening program using the state-of-the-art imaging modalities, most patients with hepatocellular carcinoma (HCC) are not eligible for curative resection due to poor hepatic functional reserve and multiplicity of the tumors. Therefore they greatly rely on percutaneous interventional procedures. Among these, transcatheter arterial chemoembolization and local ablation therapies including ethanol injection therapy or radiofrequency (RF) thermal ablation have gained wider acceptance for the local treatment of unresectable HCC with growing evidence of survival gain. Although we need more prospective randomized trials to determine the definite role of these interventional therapies, the current consensus is that they are safe and effective for the local control of small HCC and have a potential to replace definitive surgical options. In this review, the basic principles and published clinical results including long-term survival rates and complications are reviewed. The benefits and limitations of each therapy are also discussed.

Carcinoma, Hepatocellular↗

PubMed2005

Correlation between sonographic findings and infection intensity in clonorchiasis.

This prospective study was performed to evaluate the diagnostic usefulness of sonography in terms of the intensity of Clonorchis sinensis infection. Total 1,384 residents were subjected to this study at an endemic area in China, in which a clonorchiasis control program had been performed. History taking, fecal examination, and sonography were performed, and 87.8% of the subjects were found to be egg positive. Sonography showed intrahepatic bile duct dilatation (IHDD) in 68.4% of the subjects, increased periductal echogenicity (IPDE) in 24.5%, and gallbladder sludge (GBS) in 20.8%. Moreover, the grades of these sonographic findings were higher in subjects with heavier infections as determined by egg counts. IHDD was found to be the most accurate sonographic indicator of any infection degree (76.3), whereas IPDE and GBS were useful only in cases of heavy infection. Subjective symptoms were found to be only poorly correlated with sonographic findings or infection intensity.

Adolescent↗

PubMed2004

Depiction and local staging of rectal tumors: comparison of transrectal US before and after water instillation.

PURPOSE: To determine whether transrectal ultrasonography (US) with intrarectal water instillation can improve the depiction and accuracy of US in local staging of rectal tumors. MATERIALS AND METHODS: Between October 1999 and February 2002, 63 patients (mean age, 56 years; age range, 23-91 years) with 63 rectal tumors were evaluated with transrectal US before and after intrarectal water instillation. Transrectal US examinations were performed with a 7-10-MHz radial transducer. Immediately after the first transrectal US examination, the rectal lumen was filled with 50-150 mL of degassed water, and a second US examination was performed. All patients underwent surgery within 1 month after transrectal US. Depiction of the tumor was compared between the two methods. The McNemar test was used to compare the accuracy between the two techniques in local staging of the tumor by using pathologic findings in the resected specimen as the standard. RESULTS: The tumors ranged from 0.5 to 8.0 cm (mean, 2.8 cm) as measured at pathologic evaluation. All 63 tumors were clearly depicted at transrectal US after water instillation, while only 42 (67%) of the tumors were depicted at transrectal US before water instillation. In the 42 tumors clearly depicted at transrectal US examinations both before and after water instillation, the accuracy of transrectal US in local tumor staging was significantly higher after water instillation (85.7% [36 of 42]) than before water instillation (57.1% [24 of 42]; P <.001). CONCLUSION: Water instillation during transrectal US examination of rectal tumors improves the depiction and local staging of the tumors.

Adult↗

PubMed2004

Sonographic findings of active Clonorchis sinensis infection.

PURPOSE: The aim of this study was to document the characteristic sonographic findings of clonorchiasis for the diagnosis of active infection in an endemic area. METHODS: In a village in northeastern China, residents underwent fecal examinations for detection of Clonorchis sinensis eggs. Shortly thereafter, residents were examined with abdominal sonography. An experienced radiologist performed the sonographic examinations and analyzed the findings. Subjects whose fecal examinations were positive for eggs were considered to have active clonorchiasis; those whose examinations were negative for eggs were used as control subjects. The distinguishing sonographic features of active clonorchiasis were identified by stepwise logistic regression analysis. RESULTS: The study population comprised 457 subjects; fecal examinations revealed C. sinensis eggs in 316 and no eggs in 141. Four sonographic findings distinguished subjects with active clonorchiasis from control subjects: increased periductal echogenicity (p < 0.001; R = 0.11; sensitivity, 35%; specificity, 91%), floating echogenic foci in the gallbladder (p < 0.001; R = 0.09; sensitivity, 28%; specificity, 94%), diffuse dilatation of the intrahepatic bile ducts (p < 0.01; R = 0.03; sensitivity, 67%; specificity, 48%), and gallbladder distention (p < 0.05; R = 0.02; sensitivity, 3%; specificity, 100%), in decreasing order of significance. Among these 4 sonographic findings, increased periductal echogenicity and floating echogenic foci in the gallbladder were more significantly associated with active infection than were the other 2. CONCLUSIONS: Increased periductal echogenicity and floating echogenic foci in the gallbladder were identified as the 2 most significant findings for the sonographic diagnosis of active C. sinensis infection.

Adolescent↗

PubMed2004

Therapeutic efficacy and safety of percutaneous radiofrequency ablation of hepatocellular carcinoma abutting the gastrointestinal tract.

OBJECTIVE: The purpose of this study was to evaluate the therapeutic efficacy and safety of percutaneous radiofrequency ablation in the treatment of hepatocellular carcinomas abutting the gastrointestinal tract. MATERIALS AND METHODS: Forty-one patients with hepatocellular carcinomas abutting the gastrointestinal tract underwent sonographically guided percutaneous radiofrequency ablation. Forty-one tumors (1.2-4.3 cm in maximum diameter) had parts 5 mm or greater (or at least one quarter of their circumferences) abutting the stomach in 23 patients and the colon in 18 patients. Thirty tumors were ablated with internally cooled electrodes and 11 with multitined expandable electrodes. All patients were followed up for at least 1 year after ablation. Therapeutic efficacy and safety were evaluated with follow-up sonography and multiphase helical CT. RESULTS: At 1-month follow-up CT, three (7%) of the 41 tumors showed residual unablated tumor in the ablation zone. Of the remaining 38 hepatocellular carcinomas (93%) with no evidence of residual unablated tumor, four (11%) showed local tumor progression in the ablation zones on subsequent follow-up CT. We observed one major complication-a small perihepatic abscess-that needed specific treatment. CONCLUSION: Percutaneous radiofrequency ablation is an effective and safe technique for treating hepatocellular carcinomas abutting the gastrointestinal tract.

Adult↗

PubMed2004

Changes in bile ducts after radiofrequency ablation of hepatocellular carcinoma: frequency and clinical significance.

OBJECTIVE: The purpose of our study was to determine the frequency of bile duct changes after radiofrequency ablation for hepatocellular carcinoma and to evaluate their clinical significance. MATERIALS AND METHODS: Between April 1999 and August 2003, 389 patients with 521 hepatocellular carcinomas underwent a total of 571 sessions of radiofrequency ablation. The maximum dimension of the tumors measured on sonography was 2.4 +/- 0.9 cm (mean +/- SD) (range, 0.5-5.0 cm). The frequency and type of bile duct changes resulting from radiofrequency ablation, the time interval between radiofrequency ablation and the first appearance of bile duct changes, and the serial changes at follow-up CT were analyzed. Complications related to bile duct changes were also evaluated by reviewing medical records and CT scans. RESULTS: Bile duct changes occurred in 69 (12%) of 571 sessions and 66 (17%) of 389 patients. Bile duct changes seen on CT included mild dilatation of upstream bile ducts surrounding the ablation zone in 57 patients (82.6%), biloma in the ablation zone in four patients (5.8%), and both in eight patients (11.6%). The mean time interval between radiofrequency ablation and the initial appearance of bile duct change was 1.6 months (range, immediate-9 months). Most (87%) of the 69 patients with bile duct changes showed no progression on follow-up CT, and only nine (13%) had slight progression. All patients but one, in whom cholangitis developed, had no major complications requiring specific treatment during the follow-up period. CONCLUSION: Although bile duct changes were frequent after the radiofrequency ablation of hepatocellular carcinoma, most were of no clinical significance, and major complications requiring additional treatment were rare.

Adult↗

PubMed2004

Bile duct changes in rats reinfected with Clonorchis sinensis.

This study describes an evaluation of the sonographic, cholangiographic, pathological, and immunological findings, and the protective effect shown by rats reinfected with Clonorchis sinensis. Eight experimental rat groups were, namely, a normal control, a primary infection control, a reinfection I (reinfection 7 week after treatment following 3-week infection), a reinfection II (reinfection 2 week after treatment following 8-week infection), a reinfection III (exploration of the intrahepatic bile ducts 1 week after reinfection 4 week after treatment following 4-week infection), a superinfection, a secondary infection control, and an infection following immunization group. Sonographic and cholangiographic findings showed moderate or marked dilatation of the bile duct confluence in the primary infection control, reinfection II, and secondary infection control groups. Juvenile worms survived in the intrahepatic bile ducts 1 week after reinfection following treatment in the reinfection III group. It was concluded that reinfecting juvenile worms found during the first week following reinfection failed to survive or grow further. Anatomical, pathophysiological, or immunological changes may induce protection from reinfection in rats.

Animals↗

PubMed2004

Evaluation of hepatic focal nodular hyperplasia with contrast-enhanced gray scale harmonic sonography: initial experience.

OBJECTIVE: To assess the potential of contrast-enhanced gray scale harmonic sonography in the evaluation of the typical vascular and enhancement patterns of hepatic focal nodular hyperplasia. METHODS: Thirteen patients with 13 lesions of hepatic focal nodular hyperplasia underwent contrast-enhanced gray scale harmonic sonography. After the injection of a microbubble contrast agent (SH U 508A), gray scale harmonic sonographic studies using a Coded Harmonic Angio technique were performed with a combination of a period of continuous scanning to assess the vascular pattern (vascular imaging) and interval delay scanning to determine the sequential enhancement pattern (acoustic emission imaging). Each imaging pattern was categorized and analyzed by consensus of 2 experienced radiologists. RESULTS: In 12 (92%) of 13 lesions, vascular imaging during the arterial phase showed central arteries of a spoked wheel pattern, whereas the remaining lesion had stippled vascularity. On acoustic emission imaging, 11 (85%) of 13 lesions were hyperechoic during the early phase, and the remaining 2 (15%) were isoechoic compared with surrounding parenchyma. Ten (77%) of 13 lesions remained either hyperechoic (5 of 13) or isoechoic (5 of 13) during the delay phase, whereas the remaining 3 lesions (23%) were hypoechoic. CONCLUSIONS: Contrast-enhanced gray scale harmonic sonography showed the typical vascularity of a spoked wheel pattern during the vascular phase and persistent enhancement on serial acoustic emission imaging in most cases of hepatic focal nodular hyperplasia, and thereby it can be a promising technique in noninvasive diagnosis of this entity.

Adolescent↗

PubMed2003

Recurrent hepatocellular carcinoma: percutaneous radiofrequency ablation after hepatectomy.

PURPOSE: To evaluate the therapeutic efficacy and safety of percutaneous radiofrequency (RF) ablation for recurrent hepatocellular carcinoma (HCC) in the liver after hepatectomy. MATERIALS AND METHODS: Forty-five patients with 53 recurrent HCC tumors in the liver underwent percutaneous RF ablation with ultrasonographic guidance. All patients had a history of hepatic resection for HCC. The mean diameter of recurrent tumors was 2.1 cm (range, 0.8-4.0 cm). All patients were followed up for at least 10 months after ablation (range, 10-40 months; mean, 23 months). Therapeutic efficacy and complications were evaluated with multiphase helical computed tomography (CT) at regular follow-up visits. Overall and disease-free survival rates were calculated. RESULTS: At follow-up CT after initial RF ablation, 11 (21%) of 53 ablated HCC tumor sites showed residual tumor or local tumor progression. After additional RF ablation, complete ablation of 46 (87%) of 53 tumors was attained. Also at initial follow-up CT, before either additional RF ablation or other treatment was performed, 21 (47%) of 45 patients were found to have 41 new HCC tumors at other liver sites. Of these, nine tumors in eight patients were treatable with a second application of RF ablation. Overall survival rates at 1, 2, and 3 years were 82%, 72%, and 54%, respectively. No deaths or complications requiring further treatment occurred as a result of RF ablation. CONCLUSION: Percutaneous RF ablation is an effective and safe method for treating recurrent HCC in the liver after hepatectomy, with a good overall patient survival rate.

Adult↗

PubMed2003

Bowel wall thickening in patients with Crohn's disease: CT patterns and correlation with inflammatory activity.

AIM: To assess CT patterns of bowel wall thickening in patients with Crohn's disease and to correlate these patterns with inflammatory activity. MATERIALS AND METHODS: We conducted a retrospective review of 58 helical abdominal CT scans of 53 patients with pathologically proven Crohn's disease. CT patterns of thickened bowel wall were divided into four types based on patterns of mural stratification and enhancement: type A, multilayered mural stratification; type B, two layers with strong mucosal enhancement and prominent low-density submucosa; type C, two layers without strong mucosal enhancement; and type D, homogeneous enhancement. We evaluated CT findings of the bowel and adjacent structures. We also reviewed pathologic features and clinical data to determine inflammatory activity. RESULTS: Fifty-five (95%) of 58 CT examinations showed bowel wall thickening. Of these 55 CT scans, type A pattern was found in 33 (60%), type B in 10 (18%), type C in five (9%), and type D in seven (13%). CT scans with type A showed significantly more wall thickening than those with either type C or type D. Histology revealed 43 cases with active disease and 12 with quiescent appearance. Thirty of 33 CT scans with type A and all 10 with type B were classified as acute disease, and three of five with type C and six of seven with type D as quiescent. CONCLUSION: In patients with Crohn's disease, CT patterns of bowel wall thickening correlated with inflammatory activity. Thickened bowel wall with layering enhancement is predictive of acute disease, and that of homogeneous enhancement suggests quiescence.

Adolescent↗

PubMed2003

Preoperative depiction of hepatocellular carcinoma: ferumoxides-enhanced MR imaging versus triple-phase helical CT.

PURPOSE: To compare ferumoxides-enhanced magnetic resonance (MR) imaging with triple-phase helical computed tomography (CT) for the preoperative depiction of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Seventy consecutive patients with a total of 79 HCC nodules underwent ferumoxides-enhanced MR imaging and triple-phase helical CT before surgery. The diagnosis of HCC was established by means of pathologic examination after surgical resection in all patients. MR images obtained with all sequences and triple-phase helical CT images were reviewed independently by three radiologists on a segment-by-segment basis. Accuracy for diagnosis of HCC was assessed by applying receiver operating characteristic (ROC) analysis to observations of 78 hepatic segments with at least one HCC nodule and 70 segments without HCC. RESULTS: The diagnostic accuracy of findings at ferumoxides-enhanced MR imaging (with mean area-under-the-ROC-curve [A(z)] values for the three observers of 0.986, 0.979, and 0.980) was significantly higher (P <.001) than that of findings at triple-phase helical CT (with mean A(z) values for the three observers of 0.945, 0.948, and 0.964). The mean sensitivity of MR imaging (95%, 222 of 234 segments) was also significantly higher than that of triple-phase helical CT (88%, 205 of 234 segments) (P =.001, McNemar test). The mean specificity was 97% (261 of 270 segments) for MR imaging and 98% (264 of 270 segments) for CT, but this difference was not significant (P =.754, McNemar test). CONCLUSION: Ferumoxides-enhanced MR imaging is superior to triple-phase helical CT for the preoperative depiction of HCC.

Adult↗

PubMed2003

Early assessment of the therapeutic response to radio frequency ablation for hepatocellular carcinoma: utility of gray scale harmonic ultrasonography with a microbubble contrast agent.

OBJECTIVE: To evaluate the utility of gray scale harmonic ultrasonography with a microbubble contrast agent in the early assessment of the therapeutic response to radio frequency ablation for hepatocellular carcinoma. METHODS: Seventy-five patients with 81 nodular hepatocellular carcinomas (1.3-4.8 cm) treated with percutaneous radio frequency ablation were evaluated with contrast-enhanced gray scale harmonic ultrasonography after intravenous bolus injection of a galactose-based microbubble contrast agent. The vascularity within the ablation zones was evaluated with a continuous scan for 3 to 5 seconds between 15 and 30 seconds after initiation of contrast agent injection. To evaluate the perfusion of the ablation zones, intermittent stimulated acoustic emission imaging was performed with a rapid sweeping technique from the end of the continuous scan. All patients underwent follow-up 3-phase helical computed tomography at 1 month after radio frequency ablation and were followed for at least 1 year. The results of contrast-enhanced ultrasonography were compared with those of follow-up computed tomography in terms of the presence or absence of residual unablated tumors. RESULTS: In 10 (12%) of the 81 treated hepatocellular carcinomas, contrast-enhanced ultrasonography showed either nodular or crescentic enhancing foci at the margins of ablation zones, suggesting residual unablated tumors. Contrast-enhanced computed tomography obtained 1 month after radio frequency ablation confirmed the residual unablated tumors in the same 10 lesions. Diagnostic agreement between 1-month follow-up computed tomography and contrast-enhanced ultrasonography was achieved in all 81 cases (100%). CONCLUSIONS: Contrast-enhanced gray scale harmonic ultrasonography can be a reliable alternative to contrast-enhanced computed tomography in the early assessment of the therapeutic response to radio frequency ablation for hepatocellular carcinoma.

Adult↗

PubMed2002

Gastric mucosa-associated lymphoid tissue lymphoma: helical CT findings and pathologic correlation.

OBJECTIVE: The purpose of this study was to describe helical CT findings of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and to correlate them with pathologic findings. MATERIALS AND METHODS: We retrospectively reviewed CT examinations of 58 patients with confirmed gastric MALT lymphomas. Using the histopathologic grade of the MALT lymphomas, we divided the patients into two groups: those with high-grade lymphoma (n = 21) and those with low-grade lymphoma (n = 37). Common CT findings for the two groups were reviewed and compared. RESULTS: Forty (69%) of the 58 patients showed at least one abnormality of the stomach on CT. Abnormalities included diffuse or segmental gastric wall thickening (66%, 38/58), lymphadenopathy (40%, 23/58), ulcer (22%, 13/58), and gastric mass (3%, 2/58). Eighteen (31%) of 58 patients were found to have no abnormality. The high-grade group had a higher incidence of abnormalities seen on CT than the low-grade group (100% vs 51%, respectively). Gastric wall thickening in the high-grade group was more diffuse (48% vs 8%) and severe (71% vs 14%; severe or moderate) than that seen in the low-grade group. Lymphadenopathy was visualized in 67% of the high-grade group and in 24% of the low-grade group. Gastric ulcer was found in 57% of the high-grade group and in only 5% of the low-grade group. The gastric mass formation was seen in only two patients in the high-grade group. CONCLUSION: The CT findings of gastric MALT lymphoma that the two groups had in common were gastric wall thickening and lymphadenopathy. Although our results pointed to no specific CT finding for differentiating high-grade from low-grade gastric MALT lymphomas, we found that the absence of abnormality on CT is highly predictive of low-grade MALT lymphoma.

Adult↗

PubMed2002

Detection of hepatocellular carcinoma: value of adding delayed phase imaging to dual-phase helical CT.

OBJECTIVE: The purpose of our study was to determine the value of adding delayed phase imaging to dual-phase helical CT for the detection of hepatocellular carcinoma. SUBJECTS AND METHODS: One hundred thirteen patients with 131 hepatocellular carcinomas underwent triple-phase helical CT. The diagnosis was established by pathologic examination after surgical resection in all patients. For triple-phase helical CT, hepatic arterial, portal venous, and delayed phase scanning began 30, 60, and 180 sec, respectively, after the injection of 120 mL of iodinated contrast material. Dual-phase helical CT excluding delayed phase and triple-phase helical CT images were reviewed independently by three radiologists on a segment-by-segment basis. Diagnostic accuracy was assessed using receiver operating characteristic analysis in 330 resected segments. Sensitivities and specificities were calculated. The value of the delayed phase images in the characterization of hepatocellular carcinoma was also assessed. RESULTS: The diagnostic accuracy of triple-phase helical CT including delayed phase (area under the curve [A(z)], 0.973) was significantly higher than that of dual-phase helical CT (A(z), 0.954). The mean sensitivity of triple-phase CT (89%) was also significantly higher than that of dual-phase CT (86%). The mean specificities of triple-phase CT (99%) and dual-phase CT (99%) were equal. Delayed phase images were helpful in the characterization of hepatocellular carcinoma in 14% of patients. CONCLUSION: The addition of delayed phase imaging to dual-phase helical CT is valuable for the detection and characterization of hepatocellular carcinoma.

Adult↗

PubMed2002

Preoperative detection of hepatocellular carcinoma: ferumoxides-enhanced versus mangafodipir trisodium-enhanced MR imaging.

OBJECTIVE: The purpose of our study was to compare the diagnostic accuracy and lesion conspicuity of ferumoxides-enhanced MR imaging with those of mangafodipir trisodium-enhanced MR imaging for the preoperative detection of hepatocellular carcinoma. SUBJECTS AND METHODS: Twenty-one patients with 39 hepatocellular carcinomas underwent ferumoxides-enhanced and mangafodipir trisodium-enhanced MR imaging. The diagnosis was established by pathologic examination after surgical resection in all patients. Five MR sequences were obtained 30 min after ferumoxides administration, and two MR sequences were obtained before and 15 min after mangafodipir trisodium administration. Three observers independently interpreted both MR images of all sequences on a segment-by-segment basis. The diagnostic accuracy of MR imaging was assessed using receiver operating characterizing analysis. Lesion (hepatocellular carcinoma > 10 mm in diameter)-to-liver contrast-to-noise ratio was calculated on MR images. RESULTS: Ferumoxides-enhanced MR imaging (A(z) = 0.971) was significantly more accurate (p < 0.05) than mangafodipir trisodium-enhanced MR imaging (A(z) = 0.950). The mean sensitivity of ferumoxides-enhanced MR imaging (86%) was significantly greater (p < 0.05) than that of mangafodipir trisodium-enhanced MR imaging (44%) in lesions smaller than 10 mm. The mean lesion-to-liver contrast-to-noise ratio of hepatocellular carcinoma on ferumoxides-enhanced MR imaging (13.7 +/- 8.8) was significantly greater than on mangafodipir trisodium-enhanced MR imaging (5.4 +/- 5.1) (p < 0.01). CONCLUSION: Ferumoxides-enhanced MR imaging has superior diagnostic accuracy in lesions smaller than 10 mm and superior lesion conspicuity compared with mangafodipir trisodium-enhanced MR imaging for the preoperative detection of hepatocellular carcinoma.

Adult↗

PubMed2002

Assessment of therapeutic response in hepatocellular carcinoma treated with percutaneous radio frequency ablation: comparison of multiphase helical computed tomography and power Doppler ultrasonography with a microbubble contrast agent.

OBJECTIVE: To compare the results of multiphase helical computed tomography and power Doppler ultrasonography with a microbubble contrast agent in the assessment of the therapeutic response to radio frequency ablation in hepatocellular carcinoma. METHODS: In 66 patients with 73 nodular hepatocellular carcinomas ranging from 1.0 to 4.0 cm (mean, 2.6 cm) in diameter, contrast-enhanced power Doppler ultrasonography was performed after intravenous bolus injection of a galactose-based microbubble contrast agent before and after radio frequency ablation. The results of the studies were compared with the findings of follow-up 3-phase helical computed tomography. All patients were regularly followed up with computed tomography for more than 1 year (range, 13-19 months). RESULTS: In 8 (11%) of 73 hepatocellular carcinomas, immediate follow-up computed tomography obtained within 2 hours after radio frequency ablation showed focal enhancing portions within the treated lesions, suggesting residual non-necrotic tumors. All 8 of these tumors had intratumoral flow signals on contrast-enhanced power Doppler ultrasonography. The diagnostic agreement between computed tomography and contrast-enhanced power Doppler ultrasonography was achieved in 100%. Among the remaining 65 hepatocellular carcinomas with the absence of residual tumors at both immediate follow-up computed tomography and contrast-enhanced power Doppler ultrasonography, subsequent follow-up computed tomography showed local regrowth at the margins of 10 lesions (15%). CONCLUSIONS: The results of contrast-enhanced power Doppler ultrasonography closely correlated with those of immediate follow-up computed tomography for detecting residual tumors in hepatocellular carcinomas treated with radio frequency ablation. Both techniques, however, showed a limitation in detecting small or microscopic residual tumors and in predicting local regrowth in the treated lesions.

Adult↗