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Objectives: To evaluate the feasibility of simulated abbreviated MRI (AMRI) with second shot arterial phase (SSAP) for HCC surveillance and diagnosis., Methods: A total of 129 consecutive patients (age, 58.8 ± 11.4 years; male, 71.3%) underwent gadoxetic acid-enhanced MRI using a modified injection protocol for HCC evaluation from July 2017 to February 2018. The modified injection protocol consisted of routine dynamic imaging (6 mL) and SSAP imaging (4 mL). Two radiologists independently reviewed two AMRI sets: AMRI without SSAP (surveillance set) and AMRI with SSAP (diagnosis set). A modified version of the Liver Imaging Reporting and Data System (LI-RADS) for the diagnosis set was devised by referring to contrast-enhanced ultrasound LI-RADS., Results: Sixty-seven patients with HCC and 62 patients without HCC were included. In the surveillance set, sensitivity and specificity for the detection of patients with HCC were 95.5% and 96.8%, and 94.0% and 96.8% in reviewers 1 and 2, respectively. In the diagnosis set, the scores of most HCCs (76/78, 97.4%) were consistent between LI-RADS of full-protocol and modified LI-RADS of AMRI with SSAP protocol. When the HCC surveillance and diagnosis strategy was changed from strategy 1 (AMRI without SSAP) to strategy 2 (AMRI with SSAP), the recall rate significantly decreased from 52.7 to 3.9% (p < 0.001)., Conclusions: The modified LI-RADS score of the AMRI with SSAP protocol showed high agreement with the LI-RADS score of the full protocol. The HCC surveillance and diagnosis strategy using the AMRI with SSAP protocol reduced the recall rate. These results may enable to diagnose HCC simultaneously with surveillance., Key Points: • A modified version of LI-RADS was devised for the diagnostic algorithm using AMRI with the second shot arterial phase (SSAP) by referring to CEUS LI-RADS. • The modified LI-RADS scores using AMRI with SSAP showed a high concordance rate with the conventional LI-RADS score using full-protocol MRI. • The recall rate significantly decreased when the HCC surveillance and diagnosis strategy was changed from strategy 1 (AMRI without SSAP; surveillance then recall test) to strategy 2 (AMRI with SSAP; simultaneous surveillance and diagnosis)., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: Second shot arterial phase (SSAP) imaging is an additional arterial phase image obtained by re-injecting a small amount of contrast medium after routine dynamic imaging in gadoxetic acid-enhanced liver MRI. We aimed to evaluate the feasibility and additional value of a SSAP image in gadoxetic acid-enhanced liver MRI., Methods: One hundred seventy-two patients who underwent SSAP imaging after re-injection of 4 mL of contrast material after routine dynamic imaging (original) in gadoxetic acid-enhanced liver MRIs were included. Motion artifacts on arterial phase (AP) images were rated using a 5-point scale and were compared between the original AP images and SSAP images. We evaluated visual detection rates of arterial hypervascularity on the original AP and SSAP images and their subtraction images in patients with hypervascular hepatocellular carcinoma (HCC)., Results: The motion artifact of the SSAP images was significantly lower than that of the original AP images (mean score, 1.76 vs 2.06; p < 0.001). In particular, motion artifacts reduced significantly in the SSAP images of patients with substantial motion artifacts in their original AP images (2.28 vs 3.28; p < 0.001). Among the 30 HCC lesions showing hypervascularity on original AP images, only four (4/30, 13.3%) appeared hyperintense on SSAP images. However, subtraction images of SSAP clearly demonstrated arterial hypervascularity in all HCCs., Conclusion: SSAP images showed significantly fewer motion artifacts than the original AP images. Subtraction images of SSAP maintained the detectability of arterial hypervascularity, although SSAP images showed poor visual detection of arterial hypervascularity of HCC., Key Points: • Arterial phase images obtained after a second injection of a small amount of contrast medium (second shot arterial phase [SSAP]) improved motion artifacts compared to the original AP images. • The motion artifacts improved significantly in the SSAP images of patients with substantial motion artifacts in their original AP images. • Subtraction images of SSAP demonstrated the arterial hypervascularity characteristic of HCC at a level comparable to that of the original AP image.

Purpose: To identify the most reliable imaging features for differentiating hepatocellular carcinoma with paradoxical uptake on the hepatobiliary phase (HCC para ) from focal nodular hyperplasia (FNH)-like nodules using Gd-EOB-DTPA-enhanced MRI., Materials and Methods: This was a retrospective study. Twenty patients with HCC para and 21 patients with FNH-like nodules were included. The following MRI features were evaluated using 3.0 Tesla unit by two radiologists: signal intensity (SI) on T1-, T2-, and diffusion-weighted imaging (DWI), arterial enhancement pattern, washout appearance on the portal venous phase (PVP) and/or transitional phase (TP), uptake pattern on the hepatobiliary phase (HBP), "T2 scar," "EOB scar," and chemical shift on in- and out-of-phase images. Multivariate logistic regression analysis was performed to assess MRI features for prediction of HCC para ., Results: Compared with FNH-like nodules, HCC para had significantly more frequent heterogeneous T1 SI (P < 0.0001), T2 hyperintensity (P = 0.032), heterogeneous arterial enhancement (P < 0.0001), washout appearance on the PVP and/or TP (P < 0.0001), heterogeneous uptake on the HBP (P < 0.0001), absence of "EOB scar" (P < 0.0001), and hyperintensity on DWI (P = 0.004). Multivariate logistic regression analysis revealed washout appearance as the only independent imaging feature associated with HCC para (odds ratio, 7.019; P = 0.042). Washout appearance also showed the best diagnostic performance with a sensitivity of 90% and a specificity of 100%., Conclusion: Washout appearance on the PVP and/or TP is the most reliable imaging feature for differentiating HCC para from FNH-like nodules., Level of Evidence: 3 J. MAGN. RESON. IMAGING 2017;45:1599-1608., (© 2016 International Society for Magnetic Resonance in Medicine.)

Objectives: To compare diagnostic accuracy of gadoxetic acid-enhanced magnetic resonance imaging (MRI) (original set) and original MRI combined with the arterial phase of low-tube-voltage computed tomography (CT) (hybrid set)., Methods: In hybrid set, we substituted the CT arterial phase for MRI arterial phase. Three observers independently interpreted. The accuracy of each image set was evaluated using the alternative-free response receiver operating characteristic method., Results: The mean Az values for original set (0.96±0.01) was higher than that for hybrid set (0.94±0.01), but the difference was not significant (P=.10)., Conclusions: In cases with degradation of magnetic resonance arterial phase, reuse of CT arterial phase might be helpful instead of repeating MRI., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: The purpose of the study was to determine significant imaging features to differentiate between infiltrative hepatocellular carcinoma (HCC) and confluent fibrosis (CF) in liver cirrhosis using Gd-EOB-DTPA-enhanced 3-T magnetic resonance imaging., Material and Methods: Nineteen infiltrative HCCs and eight CFs were included. We evaluated the difference in imaging findings and apparent diffusion coefficient (ADC) between the two entities. We compared T2-weighted image (WI) and hepatobiliary phase (HBP) in terms of the clarity of the lesion outer margin., Results: Seventeen infiltrative HCCs showed lobulated margin, while focal CFs showed either straight (n=3) or irregular margins (n=5) (P=.001). All infiltrative HCCs had intact or bulging contours, and all focal CFs showed capsular retraction (P=.001). Fourteen infiltrative HCCs and two focal CFs showed arterial enhancement (P=.035). The ADC of infiltrative HCCs was significantly lower than that of CFs (P=.001). Satellite nodules were noted in 10 infiltrative HCCs. In terms of outer margin clarity, infiltrative HCCs showed a more distinct margin on HBP than on T2-WI (P=.005), while these two sequences were not significantly different in focal CFs (P=1.000)., Conclusion: HBP improved the imaging characteristics of infiltrative HCC, allowing it to be distinguished from focal CF. Infiltrative HCC showed lower ADC values than focal CF. Lobular configuration, contour bulging, enhancement pattern, associated satellite nodules and portal vein thrombosis were still found to be highly suggestive MR findings for infiltrative HCC., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: To assess factors affecting tumor visibility on planning ultrasound (US) for percutaneous radiofrequency (RF) ablation to treat small hepatocellular carcinomas (HCCs) primarily detected on computed tomography (CT) or magnetic resonance (MR) imaging., Materials and Methods: Patients referred for planning US for percutaneous RF ablation between September 2008 and June 2009 were prospectively enrolled from nine institutions in Korea. The first small (≤ 3 cm) single HCC or new single HCC after treatment was included. The study enrolled 898 patients (684 men and 214 women, age range 32-86 years). HCCs that were invisible on planning US were compared with visible HCCs with respect to tumor size, distance between the tumor and the diaphragm, subcapsular location, etiology of liver disease, liver cirrhosis, macronodular cirrhosis on US, ascites, Child-Pugh class, serum alpha fetoprotein (AFP) level, body mass index (BMI), previous treatments for HCC, previous chemoembolization treatments for HCC, institutions, and experience of radiologists., Results: Among 898 HCCs, 671 (74.7%) were visible on the planning US. In multivariate analysis, tumor size, distance between the tumor and the diaphragm, liver cirrhosis, and macronodular cirrhosis were statistically significant factors affecting US detection (each P < .05)., Conclusions: Smaller tumors, subphrenic location of the tumor, liver cirrhosis, and macronodular cirrhosis were independent predictors of invisible tumors on planning US., (Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.)

Purpose: To validate the diagnostic performance of quadruple phase low tube voltage liver CT through the comparison with Gd-EOB-DTPA enhanced liver MRI for the detection of HCC., Materials and Methods: Non-obese patients (38 men, eight women) with 68 HCCs underwent quadruple-phase CT at 16 MDCT (using low tube voltage, 80kVp; moderately high tube current, 280mAs) and Gd-EOB-DTPA-enhanced 3T MRI. Three observers independently and randomly reviewed the CT and MR images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for detecting HCC was assessed using alternative free-response receiver operating characteristic analysis. Sensitivity and positive predictive values were evaluated. The mean effective doses for the low dose CT were also evaluated., Results: The areas under the ROC curves were 0.963, 0.959, and 0.941 for low dose CT and 0.981, 0.982, and 0.976 for MRI. Differences in Az of the two techniques for each observer were not statistically significant (P>.05). Differences in sensitivity and positive predictive values between the two techniques for each observer were not also statistically significant: sensitivity (86.8%, 82.4%, 85.3% for CT and 95.6%, 94.1%, 91.2% for MRI) and positive predictive values (92.2%, 90.3%, 89.2% for CT and 92.9%, 92.8%, 92.5% for MRI). Six HCCs (8.8%) in five patients were observed only on hepatobiliary phase of MRI, and all were smaller than 1.5cm. The mean effective dose for CT was approximately 10.2mSv., Conclusions: Quadruple-phase low-dose liver CT (80kVp, 280mAs) had relatively good diagnostic performance for detecting HCC in non-obese patients. Because no significant difference was observed between low-dose CT and MRI, the use of low-dose liver CT can be justified based on its reduced radiation effects., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To describe the paradoxical high signal intensity of hepatocellular carcinoma (HCC) in the hepatobiliary phase on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI)., Materials and Methods: A database search was performed to identify cases of HCC that showed unusual prolonged enhancement in the hepatobiliary phase of Gd-EOB-DTPA MRI. All patients received 3.0-T liver MRI including precontrast T1-weighted images, T2-weighted images and a post Gd-EOB-DTPA-enhanced dynamic study. The signal intensity of HCC was measured at pre-enhanced, arterial, portal, delayed and hepatobiliary phase using regions of interest. Radiologic and pathologic correlation was performed for the paradoxically prolonged enhancing portion of HCC in the hepatobiliary phase., Results: Four patients (all male, age range 44-70; mean 57.5 years) were included in this study. All patients showed HCC lesions that were low signal intensity (SI) on T1-WI, high SI on T2-WI, enhanced in arterial phase, and washed-out in delayed phase. All cases showed paradoxically high SI in hepatobiliary phase, which was unusual for HCC. Pathologically, they were all diagnosed as well-differentiated HCC with prominent cytoplasm and a bile secreting appearance., Conclusion: HCC may demonstrate the prolonged high signal intensity at the hepatobiliary phase on Gd-EOB-DTPA enhanced MRI. These HCCs tended to be highly differentiated and to have prominent bile secretion., (Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the outcomes of small (5-10 mm), arterially enhancing nodules (SAENs) shown exclusively at the hepatic arterial phase of CT in a hepatocellular carcinoma (HCC) surveillance population and to determine risk factors for developing HCC., Methods: The study population included 112 patients (male:female = 100:12; aged 36-92 years) with 175 SAENs who were at risk of HCC. We evaluated serial changes during follow-up (1.4-41.8 months, mean 35.7 months) and analysed the initial CT findings of SAENs and the accompanying lesions to elucidate the risk factors for HCC development., Results: Of 175 SAENs, 101(57.7%) disappeared and 34(19.4%) persisted. Forty SAENs (22.9%) became HCC in 33 patients (29.5%). Presence of HCC treatment history (p = 0.005, risk ratio = 7.429), a larger size of SAEN (p = 0.003, risk ratio = 1.630), presence of coexistent HCC (p = 0.021, risk ratio = 3.777) and absence of coexistent typical arterioportal shunts (p = 0.003, risk ratio = 4.459) turned out to be independently significant risk factors for future development of HCC., Conclusion: SAENs were frequently seen in an HCC surveillance population and have a 22.9% probability of becoming HCC on a per-lesion basis. Risk increased particularly when the lesion was associated with a previous or concurrent HCC, a large size or found without a coexistent typical arterioportal shunt.

Objective: This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC)., Materials and Methods: Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated., Results: The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05)., Conclusion: The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.

We compared the diagnostic performance of ferucarbotran-enhanced magnetic resonance imaging (MRI) with that of gadoxetic acid-enhanced MRI for the preoperative detection of hepatocellular carcinoma (HCC) of 27 consecutive patients (male-female, 21:6; 33-76 years) with 38 surgically proven HCCs (mean diameter, 2.8 cm; range, 0.8-10.2 cm) on a 3.0-T unit. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC, sensitivity, positive and negative predictive values was evaluated. For each observer, the values of the area under the receiver operating characteristic curve (Az) were 1.000, 1.000, and 0.974 for ferucarbotran-enhanced MRI and 1.000, 0.987, and 1.000 for gadoxetic acid-enhanced MRI, and the differences were not statistically significant between 2 techniques for each observer (P > 0.05). For each observer, sensitivities were 100%, 100%, and 92.1% for ferucarbotran-enhanced MRI and 100%, 94.7%, and 100% for gadoxetic acid-enhanced MRI with no statistical significance (P > 0.005). The differences of the positive and negative predictive values of 2 techniques for each observer were not statistically significant (P > 0.05). Ferucarbotran-enhanced MRI and gadoxetic acid-enhanced MRI show a similar diagnostic performance for the preoperative detection of HCCs.

Objective: We 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)., Subjects and Methods: Sixty-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., Results: For 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)., Conclusion: Gadoxetic 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.

Objective: To evaluate the three-phase helical CT features of early hepatocellular carcinomas, based on the new Japanese classification., Materials and Methods: Over the course of an eight-year period, we collected 16 pathologically proven early hepatocellular carcinomas from 16 patients having undergone a three-phase helical CT prior to surgery. The three-phase CT images were acquired at 20-35 sec (arterial phase), 70 sec (portal phase), and 180 sec (equilibrium phase) from the beginning of intravenous injection of contrast material. All the CT images were retrospectively analyzed by two radiologists in consensus, based on their description of morphologic (size, margin, fibrous capsule and mosaic pattern) and enhancement patterns of tumors., Results: Only seven (44%) of the 16 early hepatocellular carcinomas having undergone a CT were described (mean diameter, 1.2 cm; range, 0.4-2.5 cm). All the tumors had an ill-defined margin with no fibrous capsule. The mosaic pattern was found in only one tumor. Only three (43%) of the seven tumors detected on CT were hyperattenuating during the arterial phase. The four remaining tumors (25%) were hypoattenuating throughout the three phases., Conclusion: Despite the higher resolution provided by the three phase scans, the contrast-enhanced CT provides only limited detection of the variable morphologic and enhancement features of early hepatocellular carcinomas.

Objective: To compare diagnostic performance of ferucarbotran-enhanced 3.0-T magnetic resonance (MR) imaging using parallel imaging technique with that of triple-phase multidetector row computed tomography (MDCT) for the preoperative detection of hepatocellular carcinoma (HCC)., Methods: Eighty-six consecutive patients with a total of 128 surgically proven HCCs were enrolled in this study. All patients underwent ferucarbotran-enhanced 3.0-T MR imaging using parallel imaging technique and triple-phase MDCT before hepatic resection. Three experienced radiologists independently analyzed each images on a segment-by-segment basis. The accuracy of these techniques for the detection of HCC was assessed by performing a receiver operating characteristic (ROC) analysis of 104 resected hepatic segments with at least 1 HCC and 113 resected hepatic segments without HCC., Results: The mean value of the area under the ROC curve (Az) of the ferucarbotran-enhanced 3.0-T MR imaging (0.990) was significantly higher than that of the triple-phase MDCT (0.964) (P = 0.00). The mean sensitivity of the ferucarbotran-enhanced 3.0-T MR imaging (98.1%) was significantly higher than that of the triple-phase MDCT (92.9%) (P = 0.00). The higher sensitivity was largely attributable to a greater ability of the 3.0-T MR imaging to detect small HCC (< or =1 cm) (92.6% in 3.0-T MR imaging and 37.0% in MDCT; P = 0.00). No significant difference was found for their mean specificities (98.2% in 3.0-T MR imaging and 97.6% in MDCT; P = 0.86)., Conclusions: Ferucarbotran-enhanced 3.0-T MR imaging using parallel imaging technique is a more accurate diagnostic tool than triple-phase MDCT for the preoperative detection of HCC. Ferucarbotran-enhanced 3.0-T MR imaging has a higher sensitivity than triple-phase MDCT, especially for small HCCs (< or =1 cm).

Purpose: To verify changes in the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of hypervascular hepatocellular carcinomas (HCCs) on ferucarbotran-enhanced dynamic T1-weighted MR imaging., Materials and Methods: Fifty-two patients with 61 hypervascular HCCs underwent ferucarbotran-enhanced dynamic MR imaging, and then hepatic resection. Hypervascular HCCs were identified when definite enhancement was noted during the arterial dominant phase of three-phase MDCT. Dynamic MR Images with T1-weighted fast multiplanar spoiled gradient-recalled echo sequence (TR200/TE4.2) were obtained before and 20 s, and 1, 3, 5, and 10 min, after bolus injection of ferucarbotran. We estimated the signal intensities of tumors and livers, and calculated the SNRs and CNRs of the tumors., Results: On ferucarbotran-enhanced dynamic MR imaging, SNR measurements showed a fluctuating pattern, namely, an increase in SNR followed by a decrease and a subsequent increase (or a decrease in SNR followed by a increase and a subsequent decrease) in 50 (82.0%) of 61 tumors, a single-peak SNR pattern (highest SNR on 20 s, 1, 3, or 5 min delayed images followed by a decrease) in seven (11.5%), and a decrease in SNR followed by an increase in four (6.6%). Maximum absolute CNRs with positive value were noted on 10 min delayed images in 41 (67.2%) tumors, and maximum absolute CNRs with negative value were observed on 20 s delayed images in 12 (19.7%) and on 1 min delayed images in eight (13.1%)., Conclusion: Despite showing various SNR and CNR changes, the majority of hypervascular HCCs demonstrated a fluctuating SNR pattern on ferucarbotran-enhanced dynamic MR imaging and a highest CNR on 10 min delayed image, which differed from the classic enhancement pattern on multiphasic CT.

Purpose: To assess the utility of contrast-enhanced agent detection imaging (ADI) in the assessment of the therapeutic response to percutaneous radiofrequency (RF) ablation in patients with hepatocellular carcinoma (HCC)., Materials and Methods: Ninety patients with a total of 97 nodular HCCs (mean, 2.1+/-1.3 cm; range, 1.0-5.0 cm) treated with percutaneous RF ablation under the ultrasound guidance were evaluated with contrast-enhanced ADI after receiving an intravenous bolus injection of a microbubble contrast agent (SH U 508A). We obtained serial contrast-enhanced ADI images during the time period from 15 to 90 s after the initiation of the bolus contrast injection. All of the patients underwent a follow-up four-phase helical CT at 1 month after RF ablation, which was then repeated at 2-4 month intervals during a period of at least 12 months. The results of the contrast-enhanced ADI were compared with those of the follow-up CT in terms of the presence or absence of residual unablated tumor and local tumor progression in the treated lesions., Results: On contrast-enhanced ADI, technical success was obtained in 94 (97%) of the 97 HCCs, while residual unablated tumors were found in three HCCs (3%). Two of the three tumors that were suspicious (was not proven) for incomplete ablation were subjected to additional RF ablation. The remaining one enhancing lesion that was suspicious of a residual tumor on contrast-enhanced ADI was revealed to be reactive hyperemia at the 1-month follow-up CT. Therefore; the diagnostic concordance between the contrast-enhanced ADI and 1-month follow-up CT was 99%. Of the 94 ablated HCCs without residual tumors on both the contrast-enhanced ADI and 1-month follow-up CT after the initial RF ablation, five (5%) had CT findings of local tumor progression at a subsequent follow-up CT., Conclusion: Despite its limitations in predicting local tumor progression in the treated tumors, contrast-enhanced ADI is potentially useful for evaluating the early therapeutic effect of percutaneous RF ablation for HCCs.

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.