A Modified Targetoid Feature Emphasizing Thin-Rim APHE to Improve the Diagnostic Performance of LI-RADS for Malignant Hepatic Tumors.

Objective: To identify imaging features that help distinguish between HCCs and non-HCC malignancies assigned to LI-RADS M (LR-M) and evaluate the diagnostic performance of a LI-RADS with targetoid criteria using thin-rim arterial phase hyperenhancement (APHE). Materials and Methods: This retrospective study included 381 patients (387 observations) at high-risk for HCC who underwent enhanced-MRI before surgery. Three radiologists reviewed images for LI-RADS categorization of hepatic observations. Univariate and multivariate analysis was conducted to determine reliable features to differentiate between HCC and non-HCC malignancies among the LR-M lesions. The thin-rim (<30%) APHE was defined based on the thickest thickness of rim APHE compared with the tumor radius, and a modified LI-RADS emphasizing thin-rim APHE as a specific feature of LR-M was established. We compared the diagnostic performance of modified LR-M and LI-RADS 5 (LR-5) with the conventional one. Results: Thin-rim APHE and targetoid diffusion-weighted imaging (DWI) were found as independent predictive factors of non-HCC malignancies, while enhancing capsule, thick-rim APHE and peripheral washout were noted as independent variables significantly associated with HCC of LR-M (P<0.05). The noticeable diagnostic performance of thin-rim APHE in distinguishing non-HCC malignancies from HCCs using the ROC curve. Emphasizing thin-rim APHE on targetoid features, the modified LR-M revealed significantly superior specificity and accuracy (89.4% vs 81.1%, P=0.004; and 87.9% vs 82.2%, P=0.027, respectively) while maintaining high sensitivity (82.2% vs 86.0%; P=0.529) compared with the LR-M. Meanwhile, the modified LR-5 achieved greater sensitivity and accuracy (88.6% vs 79.7%, P=0.004; and 85.8% vs 80.1%, P=0.036, respectively) for diagnosing HCC, without compromising specificity (78.3% vs.81.1%; P=0.608) compared with the LR-5. Conclusion: Thin-rim APHE may be the specific imaging feature for differentiating non-HCC malignancies from HCCs within LR-M. The modified targetoid criteria emphasizing thin-rim APHE can improve the diagnostic performance of LI-RADS for hepatic malignancies.

Intraindividual Comparison of Contrast-Enhanced Ultrasound Using Perfluorobutane With Modified Criteria Versus CT/MRI LI-RADS Version 2018 for Diagnosing HCC in High-Risk Patients.

BACKGROUND. Previously proposed modifications to LI-RADS criteria for contrast-enhanced ultrasound (CEUS) performed using perfluorobutane contrast agent yielded increased sensitivity for hepatocellular carcinoma (HCC) without a significant decrease in specificity. OBJECTIVE. The purpose of our study was to compare the diagnostic performance of CEUS with perfluorobutane using modified LI-RADS criteria versus contrast-enhanced CT or MRI using LI-RADS version 2018 (v2018) for characterizing lesions as HCC in high-risk patients. METHODS. This retrospective study included 171 patients (140 men, 31 women; mean age, 54 ± 12 [SD] years) at high-risk for HCC with a pathologically confirmed liver observation evaluated by both CEUS using perfluorobutane and contrast-enhanced CT or MRI between March 2020 and May 2021. A matching algorithm was used to select two patients with HCC for each patient with a non-HCC lesion. Two readers evaluated observations using previously proposed modifications to CEUS LI-RADS version 2017 that classify certain observations as LR-5 rather than as LR-4 or LR-M on the basis of the presence of Kupffer phase defect after perfluorobutane administration; two different readers evaluated observations using CT/MRI LI-RADS v2018. Each reader pair reached consensus. Diagnostic performance was evaluated. RESULTS. A total of 114 patients had HCC, 43 had a non-HCC malignancy, and 14 had a benign lesion. Modified CEUS criteria using perfluorobutane and CT/MRI LI-RADS v2018 showed no significant difference (p > .05) in sensitivity (92.1% vs 89.5%), specificity (87.7% vs 84.2%), or accuracy (90.6% vs 87.7%) of LR-5 for diagnosis of HCC. Of six observations assessed as LR-4 only by CT/MRI LI-RADS v2018, modified CEUS criteria using perfluorobutane assessed one as LR-3 (benign lesion) and five as LR-5 (all HCC). Of seven observations assessed as LR-M only by CT/MRI LI-RADS v2018, modified CEUS criteria using perfluorobutane assessed one as LR-3 (non-HCC malignancy) and six as LR-5 (all HCC). Eight of 12 observations assessed as LR-5 only by CT/MRI LI-RADS v2018 and 11 of 13 observations assessed as LR-5 only by modified CEUS criteria using perfluorobutane were HCC. CONCLUSION. The diagnostic performance of LR-5 for HCC diagnosis was not significantly different between modified CEUS criteria using perfluorobutane and CT/MRI LI-RADS v2018. CLINICAL IMPACT. The findings support the application of modified CEUS criteria using perfluorobutane for diagnosing HCC in high-risk patients.

Diagnosis of Non-Hepatocellular Carcinoma Malignancies in Patients With Risks for Hepatocellular Carcinoma: CEUS LI-RADS Versus CT/MRI LI-RADS.

OBJECTIVE: Data regarding direct comparison of contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) and Computed Tomography/Magnetic Resonance Imaging (CT/MR) LI-RADS in diagnosis of non-hepatocelluar carcinoma (non-HCC) malignancies remain limited. Our study aimed to compare the diagnostic performance of the CEUS LI-RADS version 2017 and CT/MRI LI-RADS v2018 for diagnosing non-HCC malignancies in patients with risks for HCC. MATERIALS AND METHODS: In this retrospective study, 94 liver nodules pathologically-confirmed as non-HCC malignancies in 92 patients at risks for HCC from January 2009 to December 2018 were enrolled. The imaging features and the LI-RADS categories on corresponding CEUS and CT/MRI within 1 month were retrospectively analyzed according to the ACR CEUS LI-RADS v2017 and ACR CT/MRI LI-RADS v2018 by two radiologists in consensus for each algorithm. The sensitivity of LR-M category, inter-reader agreement and inter-modality agreement was compared between these two standardized algorithms. RESULTS: Ninety-four nodules in 92 patients (mean age, 54 years ± 10 [standard deviation] with 65 men [54 years ± 11] and 27 women [54 years ± 8]), including 56 intrahepatic cholangiocarcinomas, 34 combined hepatocellular cholangiocarcinomas, two adenosquamous carcinomas of the liver, one primary hepatic neuroendocrine carcinoma and one hepatic undifferentiated sarcoma were included. On CEUS, numbers of lesions classified as LR-3, LR-4, LR-5 and LR-M were 0, 1, 10 and 83, and on CT/MRI, the corresponding numbers were 3, 0, 14 and 77. There was no significant difference in the sensitivity of LR-M between these two standardized algorithms (88.3% of CEUS vs 81.9% of CT/MRI, p = 0.210). Seventy-seven lesions (81.9%) were classified as the same LI-RADS categories by both standardized algorithms (five for LR-5 and 72 for LR-M, kappa value = 0.307). In the subgroup analysis for ICC and CHC, no significant differences were found in the sensitivity of LR-M category between these two standardized algorithms (for ICC, 94.6% of CEUS vs 89.3% of CT/MRI, p = 0.375; for CHC, 76.5% of CEUS vs 70.6% of CT/MRI, p = 0. 649). CONCLUSION: CEUS LI-RADS v2017 and CT/MRI LI-RADS v2018 showed similar value for diagnosing non-HCC primary hepatic malignancies in patients with risks.

Follicular Dendritic Cell Sarcomas: CT and MRI Findings in 20 Patients.

OBJECTIVE. The objective of this study was to assess the imaging features of follicular dendritic cell sarcoma (FDCS) on CT and MRI. MATERIALS AND METHODS. The clinical data and pretreatment findings of 20 patients with pathologically proven FDCS on CT (n = 15), MRI (n = 7), or both (n = 2) were analyzed retrospectively. Tumor location, number, size, morphology, attenuation or signal intensity, margin, presence of metastases, and contrast enhancement were evaluated. RESULTS. FDCS originated from lymph nodes (n = 6) or a variety of extranodal sites (n = 14). The tumors were typically solitary and well-circumscribed. Extranodal lesions (mostly in the abdomen or mediastinum with mean diameter, 11.8 cm) were larger than nodal lesions (mean diameter, 6.5 cm). Nodal-type cases presented with homogeneous masses on CT and MRI. However, on CT, all extranodal tumors (n = 12) showed heterogeneous attenuation, of which 91.7% (11/12) contained areas of lower attenuation because of internal necrosis and 50.0% (6/12) showed calcifications. On MRI, primary hepatic or splenic tumors (n = 3) also appeared as large heterogeneous masses. Seven patients (35.0%) had advanced-stage disease, and intraabdominal extranodal cases were more likely to have regional lymphadenopathy (n = 4) and distant metastases (n = 5). Hypervascularity was seen in 90.0% (18/20) of patients and progressive enhancement was seen in 11 (78.6%) of 14 tumors with multiphase imaging. CONCLUSION. FDCS is a rare, mostly solitary, well-delineated malignancy. A nodal-type FDCS typically presents as a small homogeneous mass, whereas an extranodal FDCS in the mediastinum or abdomen manifests as a large heterogeneous mass with internal necrosis and calcifications accompanied by regional lymphadenopathy. Hypervascularity and progressive enhancement can be seen in the majority of tumors.

Prognostic significance of number of nodes removed in patients with node-negative early cervical cancer.

AIM: The aim of this study was to investigate whether the number of removed lymph nodes was associated with survival of patients with node-negative early cervical cancer and to analyze the prognostic significance of clinical and pathologic features in these patients. METHODS: Patients with FIGO stage IA-IIB cervical cancer who underwent radical hysterectomy with lymphadenectomy without receiving preoperative therapy were reviewed retrospectively. Patients were all proved to have lymph-node-negative disease and classified into five groups based on the number of nodes removed. The Kaplan-Meier method and Cox's proportional hazards regression model were used in prognostic analysis. RESULTS: The final dataset included 359 patients: 45 (12.5%) patients had ≤10 nodes removed, 93 (25.9%) had 11-15, 98 (27.3%) had 16-20, 64 (17.8%) had 21-25, and 59 (16.4%) had >25 nodes removed. There was no association between the number of nodes removed and survival of patients with node-negative early cervical cancer (χ2  = 6.19, P = 0.185). Similarly, subgroup analyses for FIGO stage IB1-IIB also showed that the number of lymph nodes was not significantly related to survival in each stage. Multivariate analyses showed that histology and depth of invasion were independent prognostic factors for survival in these patients. CONCLUSION: If a standardized lymphadenectomy is performed, the number of lymph nodes removed is not an independent prognostic factor for patients with node-negative early cervical cancer. Our study suggests that there is inconclusive evidence to support survival benefit of complete lymphadenectomy among these patients.

Low-Grade and High-Grade Mucoepidermoid Carcinoma of the Lung: CT Findings and Clinical Features of 17 Cases.

OBJECTIVE: The objective of our study was to characterize the CT features and clinical findings of low-grade and high-grade mucoepidermoid carcinoma (MEC) of the lung. MATERIALS AND METHODS: The CT findings and clinical information of 17 consecutive patients with primary low-grade (n = 11) or high-grade (n = 6) MEC were analyzed retrospectively. We assessed tumor location, size, contour, margin, density, calcification, obstructive changes, presence of metastasis, and enhancement. RESULTS: In patients with low-grade MEC, tumor location was central in 10 and peripheral in one. In contrast, one and five tumors in patients with high-grade MEC were central and peripheral, respectively. There was a significant difference between central and peripheral locations among tumor grades (p = 0.005). In low-grade MECs, tumor contour was smoothly oval (n = 3) or spheric (n = 4); four were lobular. In five patients with low-grade MEC, tumors had well-defined margins; margins in the other six were poorly defined. Tumor density was homogeneous and heterogeneous in eight and three low-grade tumors, respectively. All six high-grade tumors had heterogeneous density, lobular contours, and poorly defined margins. Enhancement in both low-grade and high-grade tumors was greater than that of chest wall muscles, and low-grade tumors showed greater enhancement (46.90 ± 20.44 HU) than did high-grade tumors (22.50 ± 8.38 HU) (p = 0.015). CONCLUSION: A markedly enhanced homogeneous central bronchial nodule or mass may suggest low-grade MEC. High-grade MEC tends to be peripheral, to have poorly defined margins, and to be lobular, heterogeneous nodules or masses with less enhancement.

CT-Guided Percutaneous Step-by-Step Radiofrequency Ablation for the Treatment of Carcinoma in the Caudate Lobe.

The location of the caudate lobe and its complex anatomy make caudate lobectomy and radiofrequency ablation (RFA) under ultrasound guidance technically challenging. The objective of the exploratory study was to introduce a novel modality of treatment of lesions in caudate lobe and discuss all details with our experiences to make this novel treatment modality repeatable and educational. The study enrolled 39 patients with liver caudate lobe tumor first diagnosed by computerized tomography (CT) or magnetic resonance imaging (MRI). After consultation of multi-disciplinary team, 7 patients with hepatic caudate lobe lesions were enrolled and accepted CT-guided percutaneous step-by-step RFA treatment. A total of 8 caudate lobe lesions of the 7 patients were treated by RFA in 6 cases and RFA combined with percutaneous ethanol injection (PEI) in 1 case. Median tumor diameter was 29 mm (range, 18-69 mm). A right approach was selected for 6 patients and a dorsal approach for 1 patient. Median operative time was 64 min (range, 59-102 min). Median blood loss was 10 mL (range, 8-16 mL) and mainly due to puncture injury. Median hospitalization time was 4 days (range, 2-5 days). All lesions were completely ablated (8/8; 100%) and no recurrence at the site of previous RFA was observed during median 8 months follow-up (range 3-11 months). No major or life-threatening complications or deaths occurred. In conclusion, percutaneous step-by-step RFA under CT guidance is a novel and effective minimally invasive therapy for hepatic caudate lobe lesions with well repeatability.

1.0 T open-configuration magnetic resonance-guided microwave ablation of pig livers in real time.

The current fastest frame rate of each single image slice in MR-guided ablation is 1.3 seconds, which means delayed imaging for human at an average reaction time: 0.33 seconds. The delayed imaging greatly limits the accuracy of puncture and ablation, and results in puncture injury or incomplete ablation. To overcome delayed imaging and obtain real-time imaging, the study was performed using a 1.0-T whole-body open configuration MR scanner in the livers of 10 Wuzhishan pigs. A respiratory-triggered liver matrix array was explored to guide and monitor microwave ablation in real-time. We successfully performed the entire ablation procedure under MR real-time guidance at 0.202 s, the fastest frame rate for each single image slice. The puncture time ranged from 23 min to 3 min. For the pigs, the mean puncture time was shorted to 4.75 minutes and the mean ablation time was 11.25 minutes at power 70 W. The mean length and widths were 4.62 ± 0.24 cm and 2.64 ± 0.13 cm, respectively. No complications or ablation related deaths during or after ablation were observed. In the current study, MR is able to guide microwave ablation like ultrasound in real-time guidance showing great potential for the treatment of liver tumors.

[Liver regeneration after radiofrequency ablation versus irreversible electroporation].

OBJECTIVE: To compare liver regeneration after radiofrequency ablation versus irreversible electroporation (IRE). METHODS: A total of 10 pigs were divided into IRE and radiofrequency ablation groups. And two ablation foci were established in the liver of each pig. Computed tomography (CT)-guided IRE and radiofrequency ablation were performed. Cell death, liver regeneration and recovery speed were compared. Before ablation, immediately, 1 and 3 weeks after ablation, contrast enhanced ultrasound, CT and magnetic resonance imaging (MRI) were regularly performed. Immediately after ablation, 24 hours, 3 days, 3 weeks and 6 weeks, biopsy and pathologic examination were performed. RESULTS: At 1-3 days after IRE ablation, apoptotic cells were detected in the ablation zone and numerous red blood cells were present in hepatic cords. Three days after IRE, fibroblasts were found. Three weeks after, most ablation lesions disappeared or significantly reduced. There was no formation of fibrous capsule. And indistinct boundary existed between the surrounding liver tissue and lesion. Immediately after ablation, coagulative necrosis of ablation zone in liver was confirmed. After 3 weeks, all lesions persisted in the radiofrequency ablation group. There was formation of fibrous capsule. Immediately after ablation, the ablation volume was similar between two groups on CT scan. Three weeks later, 6 ablation foci in IRE group disappeared while another 4 lesions shrank more than 50%. There was no significant volume reduction in the radiofrequency ablation group. CONCLUSION: Compared with radiofrequency ablation, IRE resulted in faster liver regeneration and intact extracellular structure.

Gene therapy for unresectable hepatocellular carcinoma using recombinant human adenovirus type 5.

The objective of this study was to assess the clinical efficacy of genetically engineered recombinant human adenovirus type 5 (rhAd5) plus transcatheter arterial chemoembolization in patients with unresectable hepatocellular carcinoma (HCC). Data from two groups of patients with unresectable HCC were retrospectively reviewed. One group included 149 patients treated with rhAd5 injection, and the other included 150 control patients without gene therapy. Differences in short-term treatment effectiveness and adverse events were recorded and compared between the two groups. Our results indicated that for patients with higher tumor staging in the treatment group, the overall response rate and the disease control rate were higher than those in the control group, but not statistically significant (P > 0.05). The total progression free survival (PFS) and overall survival (OS) were significantly longer in the treatment group than the control group (240 vs. 196 days, P < 0.05; and 1,526 vs. 1,236 days, P = 0.000; respectively). The overall incidence rate of treatment-related adverse effects was similar (P > 0.05). No serious complications were observed. In conclusion, this study suggests that rhAd5 is a safe, effective gene therapy that prolongs the PFS and OS time of patients with unresectable HCC.