A robust and automatic CT-3D ultrasound registration method based on segmentation, context, and edge hybrid metric.

BACKGROUND: The fusion of computed tomography (CT) and ultrasound (US) image can enhance lesion detection ability and improve the success rate of liver interventional radiology. The image-based fusion methods encounter the challenge of registration initialization due to the random scanning pose and limited field of view of US. Existing automatic methods those used vessel geometric information and intensity-based metric are sensitive to parameters and have low success rate. The learning-based methods require a large number of registered datasets for training. PURPOSE: The aim of this study is to provide a fully automatic and robust US-3D CT registration method without registered training data and user-specified parameters assisted by the revolutionary deep learning-based segmentation, which can further be used for preparing training samples for the study of learning-based methods. METHODS: We propose a fully automatic CT-3D US registration method by two improved registration metrics. We propose to use 3D U-Net-based multi-organ segmentation of US and CT to assist the conventional registration. The rigid transform is searched in the space of any paired vessel bifurcation planes where the best transform is decided by a segmentation overlap metric, which is more related to the segmentation precision than Dice coefficient. In nonrigid registration phase, we propose a hybrid context and edge based image similarity metric with a simple mask that can remove most noisy US voxels to guide the B-spline transform registration. We evaluate our method on 42 paired CT-3D US datasets scanned with two different US devices from two hospitals. We compared our methods with other exsiting methods with both quantitative measures of target registration error (TRE) and the Jacobian determinent with paired t-test and qualitative registration imaging results. RESULTS: The results show that our method achieves fully automatic rigid registration TRE of 4.895 mm, deformable registration TRE of 2.995 mm in average, which outperforms state-of-the-art automatic linear methods and nonlinear registration metrics with paired t-test's p value less than 0.05. The proposed overlap metric achieves better results than self similarity description (SSD), edge matching (EM), and block matching (BM) with p values of 1.624E-10, 4.235E-9, and 0.002, respectively. The proposed hybrid edge and context-based metric outperforms context-only, edge-only, and intensity statistics-only-based metrics with p values of 0.023, 3.81E-5, and 1.38E-15, respectively. The 3D US segmentation has achieved mean Dice similarity coefficient (DSC) of 0.799, 0.724, 0.788, and precision of 0.871, 0.769, 0.862 for gallbladder, vessel, and branch vessel, respectively. CONCLUSIONS: The deep learning-based US segmentation can achieve satisfied result to assist robust conventional rigid registration. The Dice similarity coefficient-based metrics, hybrid context, and edge image similarity metric contribute to robust and accurate registration.

Intraoperative laparoscopic liver surface registration with preoperative CT using mixing features and overlapping region masks.

PURPOSE: Laparoscopic liver resection is a minimal invasive surgery. Augmented reality can map preoperative anatomy information extracted from computed tomography to the intraoperative liver surface reconstructed from stereo 3D laparoscopy. However, liver surface registration is particularly challenging as the intraoperative surface is only partially visible and suffers from large liver deformations due to pneumoperitoneum. This study proposes a deep learning-based robust point cloud registration network. METHODS: This study proposed a low overlap liver surface registration algorithm combining local mixed features and global features of point clouds. A learned overlap mask is used to filter the non-overlapping region of the point cloud, and a network is used to predict the overlapping region threshold to regulate the training process. RESULTS: We validated the algorithm on the DePoLL (the Deformable Porcine Laparoscopic Liver) dataset. Compared with the baseline method and other state-of-the-art registration methods, our method achieves minimum target registration error (TRE) of 19.9 ± 2.7 mm. CONCLUSION: The proposed point cloud registration method uses the learned overlapping mask to filter the non-overlapping areas in the point cloud, then the extracted overlapping area point cloud is registered according to the mixed features and global features, and this method is robust and efficient in low-overlap liver surface registration.

Computed Tomography-guided Techniques for Localizing Pulmonary Nodules by Localization Needle versus Methylene Blue.

OBJECTIVE: The aim of this study was to evaluate the clinical value of computed tomographyguided localization needle (LN) and methylene blue (MB) for pulmonary nodule localization. MATERIALS AND METHODS: Between November 2019 and January 2022, 547 patients underwent computed tomography-guided LN (n=171) or MB (n=376) localization and video-assisted thoracoscopic surgery (VATS) resection. RESULTS: In total, 171 and 376 nodules were localized via LN and MB, respectively, with respective technical localization success rates of 92.98 % and 88.56 % (p = 0.111). The pulmonary nodule localization time was significantly shorter for the MB group than for the LN group (p < 0.05). However, the rates of total complication, chest pain, and cough were significantly lower in the LN group (χ2 = 8.251/25.092/5.127, all p < 0.05). Furthermore, the LN group had a shorter VATS time than the MB group (p < 0.05). The VATS achieved a 100% operation success rate in both groups, and there was no significance between groups with respect to the types of surgery (p > 0.05) or the blood loss (p > 0.05). Moreover, logistic regression analysis showed that the localization technique was an independent risk factor for total complications and chest pain. CONCLUSION: Both techniques can effectively localize pulmonary nodules before VATS. MB had a shorter localization time, but the LN had a shorter VATS time and a lower incidence of complications, especially chest pain.

Intravascular treatment for abnormal catheter positioning of port-a-cath system in the subclavian vein: A single-center study.

Objective: This study aimed to explore the incidence of abnormal catheter positioning and the effectiveness and safety of intravascular adjustment or removal of abnormally positioned catheters through percutaneous punctures. Materials and methods: A retrospective analysis was conducted on 58 patients with abnormal catheter positioning, treated between January 2009 and June 2019. Intravascular adjustment of the migrated catheters and removal of the fractured catheters were performed through percutaneous puncture using a pigtail catheter, cobra catheter, and gooseneck snare. Results: Of the 58 cases, there were 23 cases of catheter migration and 35 cases of catheter fracture. The incidence of abnormal catheter positioning was 3.0%, corresponding to 1.2% migrations and 1.8% fractures. Among the 23 cases of migration, 1 case did not require adjustment and another underwent unsuccessful adjustment. The rate of successful adjustment of migrated catheters was 91.3%, whereas the rate of successful removal of fractured catheters was 100%. No surgery-related complications were observed either immediately or during the 1-month follow-up period. Conclusions: This study showed that the incidence of abnormal catheter positioning is low. Intravascular techniques used for the adjustment or removal of abnormally placed catheters are safe, efficient, and minimally invasive.

Complications from port-a-cath system implantation in adults with malignant tumors: A 10-year single-center retrospective study.

Background: Port-A-Cath systems (PCS) are safe and convenient devices for long-term infusion in patients with malignant tumors. This study retrospectively analyzed the complications from PCS and their management. Methods: Data of 1695 adults (641 males and 1054 females) with malignant tumors who underwent PCS implantation in our center from January 1, 2009 to December 31, 2019 who had complete follow-up records were collected in this study. The early and late complications and corresponding treatments were studied. Results: A total of 1716 PCSs were implanted; 21 patients underwent 2 implantations each. The success rate was 100% and no severe complications occurred during implantation. The overall occurrence rate of post-implantation complications was 18.5% (318/1716); 5.5% (94/1716) were early complications and 13.0% (224/1716) were late complications. A total of 451 PCSs were removed, of which 398 were removed due to the end of chemotherapy, while 53 were removed because of complications. A total of 4 deaths occurred from these complications. Conclusions: The incidence of intra- and post-operative complications is low. In most cases, complications can be effectively controlled without the removal of the PCS and regular follow-up and maintenance are critical.

Prediction of bile duct injury after transarterial chemoembolization for hepatocellular carcinoma: Model establishment and verification.

Objective: This study aimed to establish and validate a predictive model for bile duct injury in patients with hepatocellular carcinoma (HCC) after drug-eluting bead transarterial chemoembolization (DEB-TACE). Methods: We retrospectively analyzed 284 patients with HCC treated with DEB-TACE at our hospital between January 2017 and December 2021, of whom 63 patients experienced postoperative bile duct injuries. Univariate and logistic multivariate regression analyses were performed to identify the risk factors for bile duct injury, as well as establish and internally validate the nomogram model. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve, calibration curve, Hosmer-Lemeshow goodness of fit test, decision curve analysis (DCA), and clinical impact curve (CIC) were used to assess the predictive power, clinical value, and practicability of the nomogram model. Results: The incidence of bile duct injuries after DEB-TACE was 22.18% (63/284), with one injury occurring in every 2.86 sessions of DEB-TACE treatment. Univariate and logistic multivariate regression analyses indicated that a history of hepatectomy (odds ratio [OR]=2.285; 95% confidence interval [CI]=1.066-4.898; P<0.05), subjective angiographic chemoembolization endpoint level (OR=1.832; 95% CI=1.258-2.667; P<0.05), alkaline phosphatase (OR=1.005; 95% CI=1.001-1.010; P<0.05), and platelet count (OR=1.005; 95% CI=1.001-1.009; P<0.05) were independent risk factors for bile duct injury after DEB-TACE among patients with HCC. The risk nomogram model based on the above four variables was validated using the bootstrap method, showing consistency between the predicted and experimental values. Furthermore, the model performed well in the Hosmer-Lemeshow goodness-of-fit test (2=3.648; P=0.887). The AUC of this model was 0.749 (95% CI=0.682-0.817), with an overall accuracy of 69.01%, a positive predictive value of 73.02%, a negative predictive value of 67.87%, a sensitivity of 73.0%, and a specificity of 67.90%, suggesting that the nomogram model had good accuracy and discrimination. In addition, DCA and CIC revealed a high clinical value and practicability of the model. Conclusion: Bile duct injury in patients with HCC treated with DEB-TACE is caused by multiple factors rather than a single factor. The nomogram prediction model used in this study had a good fitting degree and prediction efficacy, with high clinical value and practicability.

Comparison of initial tumor responses to transarterial bland embolization and drug-eluting beads-transarterial chemoembolization in the management of hepatocellular carcinoma: a propensity-score matching analysis.

BACKGROUND: Transarterial bland embolization (TABE) is widely used to treat the spontaneous rupture of hepatocellular carcinoma (HCC), and can lead to ischemic necrosis of the tumor. In this study, we used the propensity-score matching (PSM) method to compare the initial responses of treatment-naïve HCC patients to TABE and drug-eluting beads-transarterial chemoembolization (DEB-TACE), and the safety of these treatments. METHODS: Patients with treatment-naïve HCC, who had been admitted to 2 medical centers from January 2016 to December 2020, were enrolled as the research subjects. The data of 26 patients treated with TABE for ruptured HCC and 52 patients treated with DEB-TACE for primary HCC were collected according to our inclusion and exclusion criteria, and a PSM analysis was conducted to assess the safety and effectiveness of these two interventional techniques 1 month postoperatively. RESULTS: In relation to ruptured HCC, TABE had a hemostatic success rate of 97.0%. Before PSM, the TABE group had a larger maximum tumor diameter (P<0.05), a higher proportion of multiple tumors (P<0.05), a higher proportion of Child-Pugh class B (P<0.05), and a higher proportion of Barcelona Clinic Liver Cancer (BCLC) stage B (P<0.05) than the DEB-TACE group. After PSM, the baseline characteristics of these two groups were well balanced, and there was no significant difference in patients' initial therapeutic responses and tumor recurrence rates (both P>0.05). The multivariate regression analysis showed that tumor size was an independent predictor of the objective response rate (ORR) [odds ratio (OR): 3.312; 95% CI: 0.152-5.944; P<0.05]. Tumor number and BCLC stage also affected ORR; however, ORR was not significantly correlated with the interventional technique (TABE vs. DEB-TACE; P>0.05). The incidences of post-embolization syndrome (PES) and 48-h hepatotoxicity were significantly lower in the TABE group than the DEB-TACE group (both P<0.05), but there was no significant difference in hepatotoxicity after 1 month (P>0.05). CONCLUSIONS: TABE is highly effective at managing hemorrhage from ruptured HCC. The initial therapeutic response of HCC to TABE is similar to that to DEB-TACE; however, TABE is associated with lower hepatotoxicity and fewer adverse effects, which paves the way for subsequent treatments and systemic therapies.

Towards quantitative and intuitive percutaneous tumor puncture via augmented virtual reality.

In recent years, the radiofrequency ablation (RFA) therapy has become a widely accepted minimal invasive treatment for liver tumor patients. However, it is challenging for doctors to precisely and efficiently perform the percutaneous tumor punctures under free-breathing conditions. This is because the traditional RFA is based on the 2D CT Image information, the missing spatial and dynamic information is dependent on surgeons' experience. This paper presents a novel quantitative and intuitive surgical navigation modality for percutaneous respiratory tumor puncture via augmented virtual reality, which is to achieve the augmented visualization of the pre-operative virtual planning information precisely being overlaid on intra-operative surgical scenario. In the pre-operation stage, we first combine the signed distance field of feasible structures (like liver and tumor) where the puncture path can go through and unfeasible structures (like large vessels and ribs) where the needle is not allowed to go through to quantitatively generate the 3D feasible region for percutaneous puncture. Then we design three constraints according to the RFA specialists consensus to automatically determine the optimal puncture trajectory. In the intra-operative stage, we first propose a virtual-real alignment method to precisely superimpose the virtual information on surgical scenario. Then, a user-friendly collaborative holographic interface is designed for real-time 3D respiratory tumor puncture navigation, which can effectively assist surgeons fast and accurately locating the target step-by step. The validation of our system is performed on static abdominal phantom and in vivo beagle dogs with artificial lesion. Experimental results demonstrate that the accuracy of the proposed planning strategy is better than the manual planning sketched by experienced doctors. Besides, the proposed holographic navigation modality can effectively reduce the needle adjustment for precise puncture as well. Our system shows its clinical feasibility to provide the quantitative planning of optimal needle path and intuitive in situ holographic navigation for percutaneous tumor ablation without surgeons' experience-dependence and reduce the times of needle adjustment. The proposed augmented virtual reality navigation system can effectively improve the precision and reliability in percutaneous tumor ablation and has the potential to be used for other surgical navigation tasks.

CT-guided localization techniques of small pulmonary nodules: a prospective non-randomized controlled study on pulmonary nodule localization needle and methylene blue staining with surgical glue.

BACKGROUND: Thoracoscopic resection of small pulmonary nodules (SPNs) is challenging. Accurate preoperative computed tomography-guided localization of SPNs is key to successful rection. The aim of the present study was to evaluate the clinical value of a novel localization needle and methylene blue staining combined with surgical glue (MBSG) and to explore the risk factors for post-localization complications. METHODS: This prospective, non-randomized controlled study was conducted on 110 patients who received either MBSG or novel needle localization prior to video-assisted thoracoscopic surgery (VATS) from January 2019 to December 2019 at Shenzhen People's Hospital. The primary endpoints were the safety and the success rates of the 2 localization techniques. The secondary endpoints were operative time and feasibility. RESULTS: The 110 patients were categorized into 2 groups: the MBSG group (n=84) and the pulmonary nodule localization needle group (n=26). The success rate of pre-VATS localization was 100% in both groups. No deaths or serious complications occurred during localization. The rates of pneumothorax, pulmonary hemorrhage, and localization-induced cough were 38.1%, 25%, and 7.14%, respectively, in the MBSG group, and 26.92%, 19.23%, and 0%, respectively, in the pulmonary nodule localization needle group. Differences between the 2 groups were not statistically significant (P>0.05). Total complication rate and the incidence of pain were significantly lower in the pulmonary nodule localization needle group (χ2=4.441 and 4.295, respectively; P<0.05). The difference in operative time between the 2 groups was not statistically significant (P>0.05). Dye diffusion occurred in 2 patients in the MBSG group; however, it had no impact on VATS or on the pathological analysis. Neither displacement nor dislocation was observed in the pulmonary nodule localization needle group. Logistic regression analysis showed that the localization technique was an independent risk factor for total complications (odds ratio: 2.634, 95% confidence interval: 1.022-6.789, P<0.05). CONCLUSIONS: Both techniques can localize SPNs effectively prior to VATS. The pulmonary nodule localization needle technique has a lower incidence of complications.

Clinical management of vascular lake during transarterial chemoembolization with CalliSpheres drug-eluting beads (DEBs) for the treatment of hepatocellular carcinoma.

BACKGROUND: To summarize the incidence and management strategy of vascular lake (VL) during the treatment of hepatocellular carcinoma (HCC) using transarterial chemoembolization (TACE) with CalliSpheres drug-eluting beads (DEBs), and to analyze its relationship with tumor response rate (RR). The etiology and clinical significance of VL were also analyzed based on the available literature. METHODS: The clinical data of 92 HCC patients who were treated with chemoembolization using CalliSpheres DEBs (DEB-TACE) in two centers were retrospectively analyzed. All 92 patients were treatment-naïve and treated by DEB-TACE. The incidence of VL and its clinical treatment during the first embolization session were summarized. The lesions were divided into a VL group and a non-VL group to analyze the relationship between VL and tumor RR. RESULTS: The embolization was successful in 98.9% of patients (91/92). A total of 33 VLs (18.4%; including 15 stable and 18 unstable VLs) were found among the 179 nodules treated. The unstable VLs were further embolized with embolic agent. One patient with unstable VL developed bleeding due to hepatic rupture and died. During the follow-up, residual tumors were found around 2 stable VLs, 2 lesions in 2 patients were treated with CT-guided radiofrequency ablation. The tumor RR was 84.4% in VL group, which was significantly higher than that (58.9%) in the non-VL group (P=0.007). CONCLUSIONS: VL is a unique phenomenon during DEB-TACE. It may be accompanied by residual tumors and bleeding due to rupture. Therefore, VL should be cautiously managed in clinical practice.

Chemoembolization with CalliSpheres drug-eluting beads loaded with irinotecan in the treatment of unresectable colorectal cancer liver metastases: preliminary results in 16 cases.

BACKGROUND: To analyze the perioperative safety and effectiveness of chemoembolization with CalliSpheres drug-eluting beads (DEBs) loaded with irinotecan (DEBIRI) in the treatment of unresectable colorectal cancer liver metastases (CRCLM). METHODS: The clinical data of 16 colorectal cancer patients with postoperative liver metastases who were treated with chemoembolization using DEBIRI in our center from March 2017 to December 2018 were retrospectively analyzed. The treatment responses 3 and 6 months after the chemoembolization was evaluated with the modified Response Evaluation Criteria in Solid Tumors (mRECIST). The clinical complications were recorded and graded. Changes in blood cells, liver function, and tumor marker were analyzed before treatment and during follow-up. RESULTS: A total of 46 DEBIRI sessions were performed in 16 patients. The success rate was 100.0%. The main postoperative complications included right upper quadrant pain (76.1%), hypertension (87.0%), nausea (89.1%), and vomiting (84.8%), which were grade 1 to 2 events; one patient suffered from acute cholecystitis (2.2%), a grade 3 event. According to mRECIST, the complete response rate, partial response rate, objective response rate, and disease control rate were 0.0%, 68.7%, 68.7%, and 100.0% 3 months after chemoembolization and 0.0%, 81.2%, 81.2%, and 93.7% 6 months after the intervention. As shown by blood biochemistry, the carcinoembryonic antigen (CEA) significantly differed before treatment and during follow-up (P<0.01), while blood cells and liver function showed no significant differences (all P>0.05). CONCLUSIONS: In this preliminary clinical study, chemoembolization with DEBIRI is safe and effective in treating unresectable CRCLM. However, more prospective multicenter clinical trials with larger sample sizes are required to confirm our findings further.