Deep learning based on carotid transverse B-mode scan videos for the diagnosis of carotid plaque: a prospective multicenter study.

OBJECTIVES: Accurate detection of carotid plaque using ultrasound (US) is essential for preventing stroke. However, the diagnostic performance of junior radiologists (with approximately 1 year of experience in carotid US evaluation) is relatively poor. We thus aim to develop a deep learning (DL) model based on US videos to improve junior radiologists' performance in plaque detection. METHODS: This multicenter prospective study was conducted at five hospitals. CaroNet-Dynamic automatically detected carotid plaque from carotid transverse US videos allowing clinical detection. Model performance was evaluated using expert annotations (with more than 10 years of experience in carotid US evaluation) as the ground truth. Model robustness was investigated on different plaque characteristics and US scanning systems. Furthermore, its clinical applicability was evaluated by comparing the junior radiologists' diagnoses with and without DL-model assistance. RESULTS: A total of 1647 videos from 825 patients were evaluated. The DL model yielded high performance with sensitivities of 87.03% and 94.17%, specificities of 82.07% and 74.04%, and areas under the receiver operating characteristic curve of 0.845 and 0.841 on the internal and multicenter external test sets, respectively. Moreover, no significant difference in performance was noted among different plaque characteristics and scanning systems. Using the DL model, the performance of the junior radiologists improved significantly, especially in terms of sensitivity (largest increase from 46.3 to 94.44%). CONCLUSIONS: The DL model based on US videos corresponding to real examinations showed robust performance for plaque detection and significantly improved the diagnostic performance of junior radiologists. KEY POINTS: • The deep learning model based on US videos conforming to real examinations showed robust performance for plaque detection. • Computer-aided diagnosis can significantly improve the diagnostic performance of junior radiologists in clinical practice.

Comparison of anatomical thermal ablation and routine thermal ablation for hepatocellular carcinoma≤50 mm: A propensity score matching.

AIM: The present study was to evaluated the clinical value of anatomical thermal ablation to treat hepatocellular carcinoma compared with routine thermal ablation. METHODS: Hepatocellular carcinoma patients with tumor diameter ≤50 mm treated by thermal ablation at our center were retrospectively enrolled from October 2015 to December 2018. Enrolled patients were grouped into the anatomical ablation group and routine ablation group, respectively. To minimize the effects of potential confounders from selection bias, a propensity score matching was carried out. Technical efficacy, recurrence and survivals rates were compared. RESULTS: Altogether 101 patients (119 lesions) were grouped into the anatomical ablation group and 101 patients (131 lesions) into the routine ablation group. The ablation zone volume of the anatomical ablation group was 36.8 (2.5-176.9) ml, significantly larger than that of the routine ablation group (28.5 [28.5 (2.8-184.3) ml] (p = 0.005)). Adjusted with propensity score matching, The 1-, 2-, and 3-year local recurrence rates were 0.0%, 0.0%, and 0.0% for the anatomical ablation group and 6.9%, 10.1%, and 10.1% for the routine ablation group, respectively (p = 0.013). The cumulative 1-, 2-, and 3-year progression-free survival rates were 93.4%, 82.7%, and 79.0% for the anatomical ablation group, 74.2%, 56.9%, and 51.6% for the routine ablation group (p = 0.001). CONCLUSIONS: Anatomical ablation could be a favorable ablation strategy to improve therapeutic effect of thermal ablation for HCC with visible feeding vessels and reserved liver function.

Utility of Fusion Imaging for Percutaneous Thermal Ablation of Hepatocellular Carcinoma in the Caudate Lobe.

The treatment outcomes of ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma in the caudate lobe with and without fusion imaging (FI) assistance were evaluated and compared. Twenty-six patients with 28 tumors in the FI group and 8 patients with 8 tumors in the non-FI group were included. Although a higher number of tumors measured >20 mm in the FI group, the technique efficacy and local tumor progression were similar between the 2 groups (P > .99 and P = .45, respectively). FI aided in the detection, guidance, and treatment monitoring of thermal ablation for caudate lobe hepatocellular carcinomas, especially for tumors measuring >20 mm.

Intra-Procedural CT/MR-Ultrasound Fusion Imaging Helps to Improve Outcomes of Thermal Ablation for Hepatocellular Carcinoma: Results in 502 Nodules.

PURPOSE: The aim was to assess the value of intra-procedural CT/MR-ultrasound (CT/MR-US) fusion imaging in the management of thermal ablation for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: This retrospective study was approved by the institutional review board. From May 2010 to October 2016, 543 HCC nodules in 440 patients (387 men and 53 women; age range: 25-84 years) that met the Milan Criteria were treated by percutaneous thermal ablation using intra-procedural CT/MR-US fusion imaging. The HCC nodules were divided into subgroups and compared (≤ 3 cm and > 3 cm, or high-risk and low-risk location, or inconspicuous and conspicuous, respectively). Technique efficacy and major complication were calculated. Cumulative local tumor progression (LTP), tumor-free and overall survival rates were estimated with the Kaplan-Meier method. RESULTS: CT/MR-US fusion imaging was successfully registered in 419 patients with 502 nodules. The technique efficacy rate of thermal ablation was 99.4 %. The major complication rate was 1.9 %. The cumulative LTP rates were 3.2 %, 5.6 % and 7.2 % at 1, 3, and 5 years, respectively. There were no significant differences for the comparisons of cumulative LTP rates between different subgroups (P = 0.541, 0.314, 0.329). The cumulative tumor-free survival rates were 74.8 %, 54.0 % and 37.5 % at 1, 3, and 5 years, respectively. The cumulative overall survival rates were 97.8 %, 87.1 % and 81.7 % at 1, 3, and 5 years, respectively. CONCLUSION: Intra-procedural CT/MR-ultrasound fusion imaging is a useful technique for percutaneous liver thermal ablation. It could help to achieve satisfying survival outcomes for HCC patients who meet the Milan Criteria.

One-lung ventilation for percutaneous thermal ablation of liver tumors in the hepatic dome.

Purpose: To investigate the feasibility, efficacy and safety of one-lung ventilation for percutaneous thermal ablation of liver tumors in the hepatic dome.Materials and methods: From 5 January 2017 to 16 April 2019, 64 patients who underwent ultrasound-guided thermal ablation with a total of 75 liver malignant tumors located in the hepatic dome were enrolled in the present study. One-lung ventilation was employed to improve the acoustic window and protect the lung and diaphragm. If the one-lung ventilation was unsuccessful, artificial pleural effusion was added. The technical efficacy was confirmed by contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) 1 month later. After that, CT/MRI was performed every 3-6 months.Results: Among the enrolled patients, the technical success rate of one lung ventilation was 92.2% (59/64). The visibility scores of tumors were improved significantly after one-lung ventilation compared to those before one-lung ventilation (p < .001). Finally, 78.6% (55/70) of the tumors achieved clinical success of one-lung ventilation to become clearly visible and underwent thermal ablation. Fourteen of the remaining 15 tumors achieved a satisfactory acoustic window after combination of artificial pleural effusion. One lesion remained inconspicuous and partly affected by pulmonary gas. The follow-up period was 8 months (3-30 months). The technical efficacy rate was confirmed to be 100% (75/75). During the follow-up period, local tumor progression occurred in 2 patients (2/75, 2.7%). Major complications occurred in two patients (2/64, 3.1%) receiving one-lung ventilation.Conclusions: One-lung ventilation is a promising noninvasive method for the thermal ablation of hepatic dome tumors due to its efficacy and safety.

CT-based radiomics for preoperative prediction of early recurrent hepatocellular carcinoma: technical reproducibility of acquisition and scanners.

PURPOSE: To test the technical reproducibility of acquisition and scanners of CT image-based radiomics model for early recurrent hepatocellular carcinoma (HCC). METHODS: We included primary HCC patient undergone curative therapies, using early recurrence as endpoint. Four datasets were constructed: 109 images from hospital #1 for training (set 1: 1-mm image slice thickness), 47 images from hospital #1 for internal validation (sets 2 and 3: 1-mm and 10-mm image slice thicknesses, respectively), and 47 images from hospital #2 for external validation (set 4: vastly different from training dataset). A radiomics model was constructed. Radiomics technical reproducibility was measured by overfitting and calibration deviation in external validation dataset. The influence of slice thickness on reproducibility was evaluated in two internal validation datasets. RESULTS: Compared with set 1, the model in set 2 indicated favorable prediction efficiency (the area under the curve 0.79 vs. 0.80, P = 0.47) and good calibration (unreliability statistic U: P = 0.33). However, in set 4, significant overfitting (0.63 vs. 0.80, P < 0.01) and calibration deviation (U: P < 0.01) were observed. Similar poor performance was also observed in set 3 (0.56 vs. 0.80, P = 0.02; U: P < 0.01). CONCLUSIONS: CT-based radiomics has poor reproducibility between centers. Image heterogeneity, such as slice thickness, can be a significant influencing factor.

Intraprocedural computed tomography/magnetic resonance-contrast-enhanced ultrasound fusion imaging improved thermal ablation effect of hepatocellular carcinoma: Comparison with conventional ultrasound.

AIM: To retrospectively compare the treatment effect of intraprocedural computed tomography/magnetic resonance-contrast-enhanced ultrasound (CT/MR-CEUS) fusion imaging (FI) with that of conventional ultrasound (US) in the guidance and assessment of thermal ablation of hepatocellular carcinoma (HCC). METHODS: The FI group (112 patients with 129 HCC) was treated between April 2010 and December 2012, whereas the US group (83 patients with 90 HCC) was treated between January 2008 and March 2010. Either CT/MR-CEUS FI or US was used to guide puncture, provide immediate assessment, and guide supplementary ablation. Technical efficacy, cumulative local tumor progression rate (LTP), recurrence-free survival (RFS), and overall survival (OS) were evaluated and compared during follow-up. Technical success rate of CT/MR-CEUS FI was also recorded. RESULTS: Technical efficacy was significantly higher in the FI group than in the US group (100% vs. 86.7%, P < 0.001). The 1-, 2-, 3-, 4-, 5-, and 6-year cumulative LTP rates in the FI group were significantly lower than in the US group (3.8%, 4.9%, 6.0%, 6.0%, 7.2%, and 7.2% vs. 16.9%, 20.1%, 25%, 25%, 25%, and 25%, respectively; P < 0.001); RFS and OS were significantly higher in the FI group than in the US group (P = 0.027 and P = 0.049, respectively). The technical success rate of FI was 85.3%. CONCLUSIONS: Intraprocedural CT/MR-CEUS FI improved the treatment effect of thermal ablation of HCC by immediately assessing treatment response and guiding supplementary ablation relative to those resulting from the use of conventional US.

Fusion imaging techniques and contrast-enhanced ultrasound for thermal ablation of hepatocellular carcinoma - A prospective randomized controlled trial.

Objectives: This randomized controlled trial (RCT) aims to compare the clinical application values of contrast-enhanced ultrasound (CEUS), computed tomography/magnetic resonance-CEUS (CT/MR-CEUS), and three-dimensional ultrasound-CEUS (3DUS-CEUS) Fusion imaging (FI) techniques in the assistance of thermal ablation for hepatocellular carcinoma (HCC).Methods: A RCT was conducted on 374 patients with 456 HCCs between January 2016 and September 2017. CEUS, CT/MR-CEUS, and 3DUS-CEUS FI techniques were randomly used to assist HCC ablation. All lesions were ablated according to a previously determined plan, and FI groups required a 5-mm ablative margin. The primary endpoints were technical efficacy of thermal ablation and local tumor progression (LTP).Results: According to randomization, 153 (18.8 ± 8.0 cm), 153 (18.3 ± 6.6 cm) and 150 (19.1 ± 6.9 cm) HCCs were assigned to CT/MR-CEUS, 3DUS-CEUS and CEUS groups respectively. Technical efficacy rates (99.3% vs. 100% vs. 100%) were achieved in the three groups, showing no statistical differences (p = 1.000). The median follow-up time was 24 (1-37) months. LTP rates at 1 and 2 years were 3.4%, 12.2% for CT/MR-CEUS FI, 4.8%, 9.0% for 3DUS-CEUS FI, and 8.6%, 19.9% for CEUS, respectively (p = .105). The results of subgroup analysis for LTP were statistically significant when patients with albumin-bilirubin (ALBI) grade 2 and 3 (p = .000), and tumor located at risky positions (p = .042). In addition, the p value in group of multiple tumors was close to .05 (p = .052).Conclusions: All the three techniques are feasible for intraoperative HCC thermal ablation. Compared with CEUS, FI techniques are more suitable in patients with ALBI grade 2 and 3, multiple tumors, and in tumors at risky locations.

Risk factors of intrahepatic biloma and secondary infection after thermal ablation for malignant hepatic tumors.

Objective: This study aimed to evaluate the risk factors of biloma formation and secondary infection after thermal ablation for malignant hepatic tumors. Patients and methods: A total of 58 patients with 68 bilomas after thermal ablation were recruited as the complication group, and 61 patients with 72 lesions without major complications were selected randomly as the control group. The potential risk factors for biloma formation were analyzed with the chi-square test and multivariate logistic regression analysis. To determine the optimum management method for biloma, patients with secondary infection were included for the subgroup analysis of risk factors. Results: A history of transcatheter arterial chemoembolization (TACE) treatment (odds ratio [OR]: 3.606, 95% confidence interval [CI]: 1.165-11.156, p = .026) and tumor location (OR: 37.734, 95% CI: 13.058-109.034, p = .000) were independent predictors of biloma formation. Among the 58 patients with biloma, 49 (84.5%) showed no symptoms (i.e., the asymptomatic group), while the remaining 9 (15.5%) developed symptoms related to secondary infections (i.e., the symptomatic group). There were significant differences in the history of biliary manipulation (p = .031) between the symptomatic and asymptomatic groups. Conclusion: A history of TACE treatment and the distance from the biliary tract were independent predictors of biloma formation after thermal ablation. Therefore, protecting the bile duct (i.e., cooling of the bile duct and combing thermal ablation with chemical ablation) should be considered for high-risk patients. Moreover, active monitoring and management should be performed for patients with bilomas who underwent biliary surgery before.

Comparison of CT/MRI-CEUS and US-CEUS fusion imaging techniques in the assessment of the thermal ablation of liver tumors.

PURPOSE: To compare the applicability of fusion imaging between contrast-enhanced ultrasound (CEUS) and computed tomography (CT) or magnetic resonance imaging (MRI) (CT/MRI-CEUS fusion imaging) and fusion imaging between CEUS and ultrasound (US-CEUS fusion imaging) in the assessment of treatment response during liver cancer ablation. METHODS: From August to December 2015, patients who underwent US-guided thermal ablation of liver tumors at our hospital with available CT/MRI images were enrolled consecutively. Both CT/MRI-CEUS and US-CEUS fusion imaging were performed in all patients to evaluate treatment responses. The applicable rate, success rate of registration and duration time were recorded. Complications were monitored in the follow-up period, and CECT/MRI within three months were taken as the standard reference of technical efficacy. RESULTS: A total of 157 liver tumors (19 ± 8 mm, range 8-55 mm) in 115 patients (54 ± 11 years old, range 2 7∼ 84 years old) were enrolled. The applicable rate of US-CEUS fusion imaging was 61.1% (96/157) because of inconspicuous lesions in US, lower than that of CT/MRI-CEUS fusion imaging (99.7% (155/157)) (p < .05). However, the success rate of registration in US-CEUS fusion imaging (93.8% (90/96)) was superior to that of CT/MRI-US fusion imaging (81.3% (126/155)) (p < .05), especially for cases combined with alternative preablation surgeries or procedures (p < .05). The technical efficacy rate was 99.3% (150/151) according to the CECT/CEMRI. CONCLUSIONS: Both CT/MRI-CEUS and US-CEUS fusion imaging are feasible means for intraprocedural immediate evaluation of treatment response for liver thermal ablation. US-CEUS fusion imaging is preferred because of its convenience and higher success rate of registration.

Radiofrequency ablation of liver cancers adjacent to the gallbladder without gallbladder isolation under contrast-enhanced ultrasound monitoring: a preliminary study.

PURPOSE: The purpose of this study was to investigate the feasibility, safety and efficacy of intra-procedural contrast-enhanced ultrasound (CEUS) monitoring of the radiofrequency ablation (RFA) of liver cancers adjacent to gallbladder (GB) without GB isolation. MATERIALS AND METHODS: From May 2016 to July 2017, patients with liver cancers adjacent to GB (≤10 mm) who intended to undergo ultrasound-guided RFA without GB isolation in our hospital were prospectively enrolled. During the RFA procedures, CEUS was employed to evaluate the therapeutic response and the perfusion of the intact GB wall. The outcomes of GB and liver cancers were followed up and recorded. RESULTS: 23 patients (18 male, 5 female) with 23 liver cancers (mean 18 mm, range 8-34 mm) adjacent to GB were enrolled. There were 12 tumors that abutted the GB while 11 tumors located within 10 mm of the GB. After the RFA procedures, intra-procedural CEUS evaluation demonstrated the perfusion of the GB wall was intact in all 23 patients and technical success rate of RFA was 100% (23/23). According to the contrast-enhanced CT/MR one month after RFA, the technical efficacy rate was 100% (23/23). During the follow-up period (range: 12-23 months, median: 17 months), no local tumor progression occurred and no major complications arised. Overall survival at 1-year was 100%. Thickening of GB wall was detected in 11 patients. The thickness of GB wall returned to the pre-ablation level in five patients. CONCLUSION: CEUS-monitored RFA of liver cancers adjacent to GB without GB isolation was feasible, safe and effective.

Intraprocedural contrast-enhanced ultrasound-CT/MR fusion imaging assessment in HCC thermal ablation to reduce local tumor progression: compared with routine contrast-enhanced ultrasound.

Purpose: To evaluate whether local tumor progression (LTP) would be further reduced when contrast-enhanced ultrasound (CEUS)-CT/MR fusion imaging was used as intraprocedural assessment method in hepatocellular carcinoma (HCC) thermal ablation compared with routine CEUS. Materials and methods: This prospective non-randomized study was conducted from December 2010 to July 2012. CEUS-CT/MR fusion imaging and routine CEUS were used for treatment response assessment in the ablation procedure of 146 HCCs and 122 HCCs, respectively. Supplementary ablations were performed immediately if necessary. The primary technique efficacy rate, LTP rate and overall survival (OS) rate were calculated. Results: For CEUS-CT/MR fusion imaging and routine CEUS, the technical success rate, technique efficacy rate and supplementary ablation rate were 86.3% (126/146) and 98.4% (120/122) (p = .000), 99.2% (125/126) and 94.2% (113/120) (p = .032), and 14.3% (18/126) and 4.2% (5/120) (p = .006), respectively. The cumulative LTP rate and OS rate were not significantly different between fusion imaging group and routine CEUS group. However, for lesions that were larger than 3 cm or close to major vessels (41 lesions in fusion imaging group and 44 lesions in routine CEUS group, who received transcatheter arterial chemoembolization before ablation), the cumulative LTP rate was significantly lower in fusion imaging group than in routine CEUS group (p = .032). Conclusion: Although intraprocedural CEUS-CT/MR fusion imaging has certain limitations in application, it might provide a potential more efficient method compared with routine CEUS in reducing LTP in HCC thermal ablation, especially for difficult ablation lesions.

Thermal ablation of hepatocellular carcinoma in patients with abnormal coagulation function.

OBJECTIVE: To evaluate the safety of thermal ablation for hepatocellular carcinoma (HCC) in patients with abnormal coagulation function. METHODS: Fifty-seven HCC tumours in 50 patients were treated with thermal ablation. All patients had a meted platelet count <50 × 109/L or international normalised ratio (INR) ≥ 1.7. Gastroscopy before ablation, platelet concentrate or fresh frozen plasma transfusion during ablation and contrast enhanced ultrasoundgraphy (CEUS)-guided ablation to cease needle tract bleeding were performed to reduce haemorrhage. The incidences of haemorrhage and other major complications were recorded and patients were followed up to observe the local tumour progression (LTP), intrahepatic distant recurrence (IDR), overall survival (OS) and recurrence-free survival (RFS) rates. RESULTS: Two incidences of needle tract bleeding and one needle tract bleeding together with bleeding at the suture of the spleen fossa were found. Three needle tract bleeding events were detected by CEUS and ceased after CEUS-guided complementary ablation. CEUS failed to detect bleeding at the suture of the spleen fossa. Therefore, a laparotomy was conducted for haemostasis. No other major complications were found after ablation. The median follow-up periods were 18.7 ± 12.0 months (range 1 ∼ 42 months) and 1 LTP and 15 IDRs occurred. The 1-, 2- and 3-year OS rates were 84.8%, 82.7% and 82.7%, and RFS rates were 67.9%, 64.0% and 64.0%, respectively. CONCLUSION: With gastroscopy before ablation, platelet concentrate or fresh frozen plasma transfusion during ablation and CEUS-guided ablation to cease needle tract bleeding, thermal ablation is a safe treatment for HCC in patients with abnormal coagulation function.

Immediate evaluation and guidance of liver cancer thermal ablation by three-dimensional ultrasound/contrast-enhanced ultrasound fusion imaging.

PURPOSE: To investigate the feasibility and value of three-dimensional ultrasound/contrast-enhanced ultrasound (3D US-CEUS) fusion imaging for the immediate evaluation of technical success and the guidance of supplementary ablation during the liver cancer thermal ablation procedure. MATERIALS AND METHODS: Patients diagnosed with malignant liver cancer intending to receive thermal ablation including radiofrequency ablation (RFA) or microwave ablation (MWA) were enrolled. 3D US-CEUS fusion imaging was used to immediately assess the technical success and guide supplementary ablation. Contrast-enhanced computed tomography/magnetic resonance imaging (CECT/CEMRI) was performed one month after ablation to assess the technique effectiveness of the ablation. The registration success rate, duration time of 3D US-CEUS fusion imaging, technique effectiveness rate and major complications were recorded. RESULTS: In total, 76 patients with 95 tumours who underwent RFA or MWA and assessed by 3D US-CEUS fusion imaging were enrolled. The registration success rate of 3D US-CEUS fusion imaging was 93.7% (89/95), and the duration time was 4.0 ± 1.1 min. Thirty lesions received supplementary ablation immediately during the procedure. The technique effectiveness rate of the ablation was 98.8% (81/82). There were no major complications related to ablation. CONCLUSIONS: 3D US-CEUS fusion imaging is a feasible and valuable technique for the immediate evaluation and guidance of supplementary ablation during the liver cancer thermal ablation procedure.

Potential application of ultrasound-guided thermal ablation in rare liver tumors.

BACKGROUND: With the advances of imaging techniques, the detection rate of rare liver tumor is increased. However, the therapeutic strategies of the rare liver tumors remain limited. METHODS: We analyzed twelve pathologically confirmed rare liver tumors in 8 patients. All of the patients underwent ultrasound (US) guided biopsy and subsequent thermal ablation. The tumors were ablated according to the preoperative plans and monitored by real-time US. CT/MRI fused with contrast enhanced US (CEUS) or three-dimensional (3D) US-CEUS images were used to guide and assess the ablation zone more accurately during thermal ablation. The rate of technical efficacy was assessed based on the contrast-enhance CT/MRI (CECT/MRI) results one month after ablation. Local tumor progression (LTP), recurrence and complications were followed up and recorded. RESULTS: Among these twelve nodules, nine were subject to US-guided thermal ablation, whereas the other three inconspicuous nodules were subject to CEUS-guided thermal ablation. Intra-procedure CT/MRI-CEUS or 3D US-CEUS fusion imaging assessments demonstrated that the ablation zone sufficiently covered the original tumor, and no immediate supplementary ablation was required. Additionally, no major complications were observed during the follow-up period. The postoperative CECT/MRI confirmed that the technique success rate was 100%. Within the surveillance period of 13 months, no LTP or recurrence was noted. CONCLUSIONS: US-guided thermal ablation was feasible and safe for rare liver tumors. The use of fusion imaging technique might make US-guided thermal ablation as effective as surgical resection, and this technique might serve as a potential therapeutic modality for rare liver tumors in the future.

Evaluation of the ablation margin of hepatocellular carcinoma using CEUS-CT/MR image fusion in a phantom model and in patients.

BACKGROUND: To assess the accuracy of contrast-enhanced ultrasound (CEUS)-CT/MR image fusion in evaluating the radiofrequency ablative margin (AM) of hepatocellular carcinoma (HCC) based on a custom-made phantom model and in HCC patients. METHODS: Twenty-four phantoms were randomly divided into a complete ablation group (n = 6) and an incomplete ablation group (n = 18). After radiofrequency ablation (RFA), the AM was evaluated using ultrasound (US)-CT image fusion, and the results were compared with the AM results that were directly measured in a gross specimen. CEUS-CT/MR image fusion and CT-CT / MR-MR image fusion were used to evaluate the AM in 37 tumors from 33 HCC patients who underwent RFA. RESULTS: The sensitivity, specificity, and accuracy of US-CT image fusion for evaluating AM in the phantom model were 93.8, 85.7 and 91.3%, respectively. The maximal thicknesses of the residual AM were 3.5 ± 2.0 mm and 3.2 ± 2.0 mm in the US-CT image fusion and gross specimen, respectively. No significant difference was observed between the US-CT image fusion and direct measurements of the AM of HCC. In the clinical study, the success rate of the AM evaluation was 100% for both CEUS-CT/MR and CT-CT/MR-MR, and the duration was 8.5 ± 2.8 min (range: 4-12 min) and 13.5 ± 4.5 min (range: 8-16 min) for CEUS-CT/MR and CT-CT/MR-MR, respectively. The sensitivity, specificity, and accuracy of CEUS-CT/MR imaging for evaluating the AM were 100.0, 80.0, and 90.0%, respectively. CONCLUSIONS: A phantom model composed of carrageenan gel and additives was suitable for the evaluation of HCC AM. CEUS-CT/MR image fusion can be used to evaluate HCC AM with high accuracy.

Improvement of ablative margins by the intraoperative use of CEUS-CT/MR image fusion in hepatocellular carcinoma.

BACKGROUND: To assess whether intraoperative use of contrast-enhanced ultrasound (CEUS)-CT/MR image fusion can accurately evaluate ablative margin (AM) and guide supplementary ablation to improve AM after hepatocellular carcinoma (HCC) ablation. METHODS: Ninety-eight patients with 126 HCCs designated to undergo thermal ablation treatment were enrolled in this prospective study. CEUS-CT/MR image fusion was performed intraoperatively to evaluate whether 5-mm AM was covered by the ablative area. If possible, supplementary ablation was applied at the site of inadequate AM. The CEUS image quality, the time used for CEUS-CT/MR image fusion and the success rate of image fusion were recorded. Local tumor progression (LTP) was observed during follow-up. Clinical factors including AM were examined to identify risk factors for LTP. RESULTS: The success rate of image fusion was 96.2% (126/131), and the duration required for image fusion was 4.9 ± 2.0 (3-13) min. The CEUS image quality was good in 36.1% (53/147) and medium in 63.9% (94/147) of the cases. By supplementary ablation, 21.8% (12/55) of lesions with inadequate AMs became adequate AMs. During follow-up, there were 5 LTPs in lesions with inadequate AMs and 1 LTP in lesions with adequate AMs. Multivariate analysis showed that AM was the only independent risk factor for LTP (hazard ratio, 9.167; 95% confidence interval, 1.070-78.571; p = 0.043). CONCLUSION: CEUS-CT/MR image fusion is feasible for intraoperative use and can serve as an accurate method to evaluate AMs and guide supplementary ablation to lower inadequate AMs.

Two-dimensional shear-wave elastography and conventional US: the optimal evaluation of liver fibrosis and cirrhosis.

PURPOSE: To evaluate the individual and combined performances of two-dimensional (2D) shear-wave elastography (SWE) and conventional ultrasonography (US) in assessing liver fibrosis and cirrhosis to determine when 2D SWE should be added to routine US. MATERIALS AND METHODS: This prospective study was approved by the institutional ethics committee, and the patients provided written informed consent. Between April 2012 and March 2013, conventional US and 2D SWE examinations were performed in 198 patients (mean age, 37.7 years; age range, 18-67 years) with chronic liver disease. Liver biopsy was used as a reference standard for 167 patients; the other 31 patients had decompensated liver cirrhosis. Receiver operating characteristic (ROC) curves were obtained to assess the diagnostic performance. Differences between the areas under the ROC curves (AUCs) were compared by using a Delong test. RESULTS: Two-dimensional SWE was significantly superior to US in diagnosis of significant fibrosis (score of F2 or greater) (AUC, 0.862 vs 0.725; P = .001) and early cirrhosis (score of F4) (AUC, 0.926 vs 0.789; P = .007). Combining 2D SWE with US did not increase the performance of depicting either significant fibrosis or liver cirrhosis (P = .713 and 0.410, respectively) relative to 2D SWE alone. There was no significant difference between 2D SWE and US in diagnosis of decompensated cirrhosis (AUC, 0.878 vs 0.925; P = .323). In addition, combining 2D SWE with US did not increase the performance relative to that of US alone (P = .372). CONCLUSION: Conventional US is sufficient to detect decompensated cirrhosis. Two-dimensional SWE is significantly superior to US in detecting liver fibrosis. Combining 2D SWE and US did not improve the diagnostic performance for either fibrosis or cirrhosis.

A clinical validation study for the feasibility and reliability of three-dimensional ultrasound-ultrasound automatic image registration.

PURPOSE: The purpose of our study was to assess the feasibility and reliability of 3D ultrasound-ultrasound (US-US) automatic registration-based analysis of the hepatic vessel tree (VT) (3D VT-based automatic registration) in clinical applications. MATERIALS AND METHODS: A total of 70 pairs of 3D ultrasound data were acquired from the livers of 10 healthy volunteers enrolled in the study. An automatic registration method was applied to the acquired volumetric data pairs, and anatomic landmarks were picked by an experienced sonographer as 'ground truth'. The influences of respiration phase, subject posture, and liver lobe on data acquisition and scan volumetric angle on the registration accuracy and robustness were investigated. The registration time, success rate, median registration error distance, and sonographer's subjective feedback were assessed. RESULTS: The time required for the 3D VT-based automatic registration was approximately 15∼20 s. Overall, the success rate for the hepatic vessel-based registration was 71% (50/70), and the median registration error distance was 1.72 mm (0.57∼4.71 mm). When the influential factors were well controlled, the optimal registration accuracy (median registration error distance = 1.22 mm) could be obtained with an excellent success rate of 100% (10/10). According to the subjective assessment of the sonographer, over 90% (45/50) of the automatic registration results were not inferior to the ground truth. Among them, 42% (21/50) were superior to the fusion results from the ground truth. CONCLUSIONS: The results suggest that the 3D VT-based automatic registration is feasible and reliable and has potential for guidance and evaluation of intraoperative ablation of hepatocellular carcinoma.

Reliability and stability of ultrasound-guided attenuation parameter in evaluating hepatic steatosis.

PURPOSE: This study aimed to explore the reliability and stability of ultrasound-guided attenuation parameter (UGAP) values obtained by two measuring methods and different measuring times. METHODS: Patients who underwent liver UGAP examinations in our hospital from September 2022 to December 2022 were retrospectively analyzed. The clinical data and UGAP measurements results were collected. Two different measuring methods: static single-frame multi-point measuring and dynamic multi-frame single-point measuring, were performed for each patient, and 10 UGAP values of each measuring method were recorded. The medians of the UGAP values of the 1st-3rd, 1st-5th, 1st-7th and 1st-10th by each measuring method were taken as the final UGAP values of measuring 3, 5, 7 and 10 times. The UGAP values obtained by the two different measuring methods and different measuring times (3, 5, 7 or 10 times) were compared. RESULTS: 206 patients were included in this study. There was no statistical difference between UGAP values measured by static single-frame multi-point measuring and dynamic multi-frame single-point measuring (P = 0.689, P = 0.270, P = 0.298, P = 0.091), regardless of measuring times (3, 5, 7, 10 times). No significant difference between the UGAP values obtained by 3, 5, 7 and 10 measurements was found (P = 0.554, P = 0.916). CONCLUSION: The UGAP values obtained by the two different measuring methods and different measuring times (3, 5, 7 and 10 times) are stable and reliable. Additionally, 3 times of UGAP measurements might be enough for each patient in clinical practice.