Multimodal Imaging Guidance Research Articles

Abstract 13679: Personalized Guidance of Edge-to-Edge Transcatheter Tricuspid Valve Repair

Introduction: Transcatheter edge-to-edge tricuspid valve repair (T-TEER) for tricuspid regurgitation (TR) is always guided by TEE. Hypothesis: Safety and efficacy of T-TEER can be increased by multimodality imaging (MMI) guidance. Methods: From December 2020 to January 2022, we performed T-TEER in 40 inoperable patients. All patients received TTE, TEE and cardiac CT screening, and were assigned to a MMI (n=17) guidance group, provided good TTE acoustic window, or otherwise classical TEE (n=23). Multimodality imaging employed the 4 right-sided chamber views. Accordingly, the 1-chamber view was obtained in the transgastric short-axis view on TEE, but also from a modified subcostal TTE short axis. The 2-chamber view was visualized from a low-esophageal position, or from a parasternal long axis view of the right ventricle. The 3-chamber view was seen on mid-esophageal TEE 50-100°, but also in the parasternal short axis view. Finally, the 4-chamber view was obtained on mid-esophageal 0-30°, or the classical four-chamber TTE view. CT derived fluoroscopic angulations of these views allowed interventionalists and imaging specialists to speak a common language. Results: Device success was achieved in all patients, with 1.5±0.6 implanted clips / patient in the MMI vs 1.5±0.5 in the TEE group (p=0.851). Device times were 66.1±35.1 vs 58.7±27.5 minutes (p=0.459). TR reduction was successful in 94% vs 95% of patients, p=1.000. Two- or more grade TR improvement occurred in 65% vs 52% of cases. There were no device associated complications but 3 TEE-related gastro-esophageal bleedings occurred in the 2 nd group. By 12 months, 4 vs 8 patients (p=0.504) were readmitted for acute heart failure, and 2 vs 4 (p=0.686) died. NYHA class decreased by one grade in all survivals. However, Kansas City Cardiomyopathy Questionnaire score and 6-minute walk distance significantly increased in each respective group, more with MMI ( Δ 29±21.4 vs 22±13.6 points, p=0.227; Δ 101±100.4 vs 85±64 meters, p=0.121). Conclusions: A patient-tailored MMI approach to T-TEER guidance, by using TTE in patients with good acoustic window and cardiac CT for fluoroscopic determination of the 4 right-sided chamber views, is feasible and improves safety, procedural success and, in turn, clinical outcomes.

Enhancing epidural needle guidance using a polarization-sensitive optical coherence tomography probe with convolutional neural networks.

Epidural anesthesia helpsmanage pain during different surgeries. Nonetheless, the precise placement of the epidural needle remains a challenge. In this study, we developed a probe based on polarization-sensitive optical coherence tomography (PS-OCT) to enhance the epidural anesthesia needle placement. The probe was tested on six porcine spinal samples. The multimodal imaging guidance used the OCT intensity mode and three distinct PS-OCT modes: (1) phase retardation, (2) optic axis, and (3) degree of polarization uniformity (DOPU). Each mode enabled the classification of different epidural tissues through distinct imaging characteristics. To further streamline the tissue recognition procedure, convolutional neural network (CNN) were used to autonomously identify the tissue types within the probe's field of view. ResNet50 models were developed for all four imaging modes. DOPU imaging was found to provide the highest cross-testing accuracy of 91.53%. These results showed the improved precision by PS-OCT in guiding epidural anesthesia needle placement.

Measurement and analysis on distribution of radiation field dose inside the treatment room of TaiChi Pro multimodal integrated digital radiotherapy system

ObjectiveTo examine the leakage radiation dose from the accelerator module's primary beam self-shielding, as well as stray radiation levels and distribution in the treatment room across various planes for the innovative X/γ multimodal radiotherapy system, TaiChi Pro, which is the world's first digitally integrated system that combines a linear accelerator, multi-source rotational focused gamma knife, and multi-modal image guidance, in order to formulate treatment room safety strategies and estimate additional radiation doses to patients. MethodsThe TaiChi Pro multi-mode integrated radiotherapy system was utilized with a 6 ​MV X-ray accelerator in the flatten-filter free (FFF) treatment mode. The system has a primary radiation beam self-shielding, and an isocenter dose rate of 800 ​cGy/min. For detection points in various planes, an x, y, z coordinate system was established with the isocenter as the origin. To simulate the situation of patient, water-equivalent phantom was employed. The ambient dose equivalent and ambient dose equivalent rate at detection points in the radiation field were measured using thermoluminescence dosimeters. ResultsThe self-shielding area achieved a maximum dose of 114.0 ​mGy at 1 m distance from the target point after 3 ​min of cumulative irradiation. The leakage radiation ratios at all points remained below 0.5%, fulfilling the self-shielding design requirements. Regarding the couch, the highest radiation was observed in the opposite direction of the beam at the target point. The stray radiation on the treatment bed plane resulted in an ambient dose equivalent that did not exceed 0.5% of the ambient dose equivalent at the central point. ConclusionThe levels and distribution patterns of stray and leakage radiation inside the TaiChi Pro treatment room meet the requirements of the relevant national standard. The measured values of indoor radiation levels and distribution are very useful for room shielding design and personnel protection.

Stereotactic Boost and Short-Course Radiotherapy for p16-Associated Oropharynx Cancer (SHORT-OPC): First Planned Interim Safety Analysis from a Randomized Phase II Trial

There is a need for safe treatment de-intensification in p16+ oropharynx cancer (OPC). The standard of care (SOC) radiotherapy (RT) regimen is cumbersome and associated with high toxicity. Stereotactic radiotherapy (SBRT) and multimodality image guidance is an opportunity to precisely target the gross tumor while safely reducing elective irradiation dose. We aim to assess the safety and efficacy of a short course RT for p16+ OPC, consisting of an SBRT boost to the gross tumor volume (GTV) followed by de-escalated elective irradiation. In this randomized phase II trial, patients with p16-positive, stage I-II OPSCC with primary tumor <30 cc (8th Ed AJCC) are planned with combined CT, MRI and FDG-PET, and randomized to 1) SBRT boost (14 Gy in 2 fractions) to the GTV followed with de-escalated RT (+/- Cisplatin) to a dose of 40 Gy in 20 fractions, or 2) SOC RT (+/- Cisplatin) to a dose of 70 Gy in 33 fractions to the GTV and 59.4-54Gy (or equivalent) to the intermediate-to-low dose elective region. Patients are stratified by stage (I vs. II) and use of chemotherapy. The primary endpoint of the trial is locoregional control at 2 years, powered for a sample size of 100 patients. A Bayesian adaptive design includes 2 planned safety interim analysis using grade ≥ 3 subacute toxicities >40% as a stopping criterion, and 1 planned futility analysis. Acute adverse events (AE) are defined as those occurring ≤ 60 days from RT, subacute AE between 60-180 days after RT, and late AE >180 days from RT. This is the first planned toxicity analysis. Twenty-one patients were randomly assigned and eligible (11 in SOC and 10 in experimental arm). Median age was 69 years (range 49-84); 29% and 71% had stage T1 and T2, while 10%, 85% and 1 patient had N0, N1 and N2 disease, respectively. RT alone and chemoradiation was administered in 67% and 33% of patients, respectively. At a median follow-up of 11 months (range 1.7-17.6), there was 1 local recurrence at the primary tumor site in the SOC arm (at 10 month) and no recurrence in the experimental arm. All enrolled patients remain alive at the time of analysis. There was a 54.5% rate of grade 3 acute AE in the SOC arm and 30.0% rate of grade 3 acute AE in the experimental arm. More specifically, 1, 5 (45%), 2 (18%), and 2 (18%) versus 0, 1, 1 and 1 patient developed acute grade 3 dysphagia, mucositis, pain and dermatitis in the SOC and experimental arm, respectively. There was no acute grade 4 or 5 toxicity. There was no grade ≥ 3 subacute toxicity or late toxicity in both arms. This primary safety analysis showed that SBRT boost followed by a short course of de-escalated elective irradiation in p16+ OPC has limited early toxicity and meets criteria for study continuation.

Advances in TEE-Centric Intraprocedural Multimodal Image Guidance for Congenital and Structural Heart Disease.

Percutaneous interventions are gaining rapid acceptance in cardiology and revolutionizing the treatment of structural heart disease (SHD). As new percutaneous procedures of SHD are being developed, their associated complexity and anatomical variability demand a high-resolution special understanding for intraprocedural image guidance. During the last decade, three-dimensional (3D) transesophageal echocardiography (TEE) has become one of the most accessed imaging methods for structural interventions. Although 3D-TEE can assess cardiac structures and functions in real-time, its limitations (e.g., limited field of view, image quality at a large depth, etc.) must be addressed for its universal adaptation, as well as to improve the quality of its imaging and interventions. This review aims to present the role of TEE in the intraprocedural guidance of percutaneous structural interventions. We also focus on the current and future developments required in a multimodal image integration process when using TEE to enhance the management of congenital and SHD treatments.

Cone Beam Computed Tomography Image Fusion with Cross Sectional Images for Percutaneous Renal Tumor Ablation: Preliminary Data.

Percutaneous ablative treatments in the kidney are now standard options for local cancer therapy. Multimodality image guidance, combining two 3D image sets, may improve procedural images and interventional strategies. We aimed to assess the value of intra-procedural cone beam computed tomography (CBCT) with magnetic resonance (MR) or CT imaging fusion technique in the guidance of percutaneous microwave ablation (MWA) of renal neoplasms. Fifteen patients (eight males, seven females, median age 65 years, median lesion size 20 mm) underwent percutaneous MWA for 15 renal tumors. All the procedures were performed in a dedicated angiography room setting; CBCT ablation planning capabilities included multimodality image fusion. Preoperative contrast-enhanced CT was available in 12 patients, whereas magnetic resonance imaging in the remaining. All patients were considered inoperable due to comorbidities, advanced age, and/or refusal to undergo surgery. Exclusion criteria were: tumors visible at unenhanced CBCT, metastatic disease, and uncorrected coagulopathy. Technical success and technical effectiveness were calculated. Procedural time, complications and recurrences were registered. MWA under CBCT-guidance with fusion technique was technically successful in 14 out of 15 cases (93%). The median procedural time was 45 min. No procedure-related complications were reported. No enhancing tissue was visualized in the area of ablation at 1-month follow-up. All 15 cases were recurrence-free at last follow-up assessment (median follow-up of 12 months); no cancer-specific deaths were registered. CBCT-CT/MR image fusion is technically feasible and safe in achieving correct targeting and complete ablation of renal lesions. This approach bears the potential to overcome most of the limitations of unenhanced CBCT guidance alone; larger series are needed to validate this technique.

7736 Transcatheter Drainage and Ethanol Sclerotherapy for Treatment of Symptomatic Endometriomas: A Case Series

<h3>Study Objective</h3> To investigate the efficacy of ethanol sclerotherapy for endometriomas as either pre-operative adjuvant therapy to facilitate minimally invasive surgery or as definitive treatment. <h3>Design</h3> This is a case series of 15 patients treated from 2010-2022 who presented with endometriomas causing bulk symptoms and pain. We reviewed pre-procedure imaging, surgical history, procedural findings, post-procedure treatment course and symptom changes, and most recent interval imaging if available. <h3>Setting</h3> Multidisciplinary academic complex gynecology center with multimodal imaging guidance. <h3>Patients or Participants</h3> Patient age range was 21-61 years. Five patients had a history of surgical resection for endometriomas. All patients had endometriomas diagnosed with CT or MR and associated symptoms including bulk and pain. <h3>Interventions</h3> Patients underwent image-guided transabdominal, transvaginal, or transgluteal catheter drainage of their endometriomas. The endometrioma was completely evacuated and contrast study was performed to determine cavity volume (for ethanol injection) and complete emptying of the cavity. Ethanol 100% was instilled two times with a dwell time of 5-7 minutes each and then evacuated. The median total volume of alcohol instilled was 100 cc (range 55-600 cc). The drain was usually left in place; patients returned at 24-96 hours for repeat contrast study and a third ethanol injection followed by catheter removal. <h3>Measurements and Main Results</h3> The median volume of endometriotic material drained was 200 cc (range 30-2000 cc). All patients reported symptomatic improvement immediately following the procedure. Interval imaging was available for 11 patients (interval length range 32-837 days) with an average reduction in volume of 83.5% (range 53.2%-100%). 6 patients underwent subsequent surgery for endometriomas. There was one complication – secondary infection requiring repeat drainage. <h3>Conclusion</h3> Ethanol sclerotherapy is an effective treatment for improving endometrioma symptoms and can delay or obviate the need for surgery. It should continue to be studied on a larger scale to ascertain its optimal role in endometrioma treatment.

The role of guidance in delivering cardiac resynchronization therapy: A systematic review and network meta-analysis

Positioning the left ventricular lead at the optimal myocardial segment has been proposed to improve cardiac resynchronization therapy (CRT) response. We performed a systematic review and network meta-analysis evaluating echocardiographic and clinical response delivered with different guidance modalities compared to conventional fluoroscopic positioning. Randomized trials with ≥6 months follow-up comparing any combination of imaging, electrical, hemodynamic, or fluoroscopic guidance were included. Imaging modalities were split whether one modality was used: cardiac magnetic resonance (CMR), speckle-tracking echocardiography (STE), single-photon emission computed tomography, cardiac computed tomography (CT), or a combination of these, defined as "multimodality imaging." Twelve studies were included (n = 1864). Pair-wise meta-analysis resulted in significant odds of reduction in left ventricular end-systolic volume (LVESV) >15% (odds ratio [OR] 1.50, 95% confidence interval [CI] 1.05-2.13, P = .025) and absolute reduction in LVESV (standardized mean difference [SMD] -0.25, 95% CI -0.43 to -0.08, P = .005) with guidance. CMR (OR 55.3, 95% CI 4.7-656.9, P = .002), electrical (OR 17.0, 95% CI 2.9-100, P = .002), multimodality imaging (OR 4.47, 95% CI 1.36-14.7, P = .014), and hemodynamic guidance (OR 1.29-28.0, P = .02) were significant in reducing LVESV >15%. Only STE demonstrated a significant reduction in absolute LVESV (SMD -0.38, 95% CI -0.68 to -0.09, P = .011]. CMR had the highest probability of improving clinical response (OR 17.9, 95% CI 5.14-62.5, P < .001). Overall, guidance improves CRT outcomes. STE and multimodality imaging provided the most reliable evidence of efficacy. Wide CIs observed for results of CMR guidance suggest more powered studies are required before a clear ranking is possible.

Tumor Microenvironment Stimuli-Responsive Single-NIR-Laser Activated Synergistic Phototherapy for Hypoxic Cancer by Perylene Functionalized Dual-Targeted Upconversion Nanoparticles.

Although synergistic therapy has shown great promise for effective treatment of cancer, the unsatisfactory therapeutic efficacy of photothermal therapy/photodynamic therapy is resulted from the absorption wavelength mismatch, tumor hypoxia, photosensitizer leakage, and inability in intelligent on‐demand activation. Herein, based on the characteristics of tumor microenvironment (TME), such as the slight acidity, hypoxia, and overexpression of H2O2, a TME stimuli‐responsive and dual‐targeted composite nanoplatform (UCTTD‐PC4) is strategically explored by coating a tannic acid (TA)/Fe3+ nanofilm with good biocompatibility onto the upconversion nanoparticles in an ultrafast, green and simple way. The pH‐responsive feature of UCTTD‐PC4 remains stable during the blood circulation, while rapidly releases Fe3+ in the slightly acidic tumor cells, which results in catalyzing H2O2 to produce O2 and overcoming the tumor hypoxia. Notably, the emission spectrum of the UCTTD perfectly matches the absorption spectrum of the photosensitizer (perylene probe (PC4)) to achieve the enhanced therapeutic effect triggered by a single laser. This study provides a new strategy for the rational design and development of the safe and efficient single near‐infrared laser‐triggered synergistic treatment platform for hypoxic cancer under the guidance of multimodal imaging.

A novel ultrasound probe calibration method for multimodal image guidance of needle placement in cervical cancer brachytherapy

PurposeInterstitial needles placement is a critical component of combined intracavitary/interstitial (IC/IS) brachytherapy (BT). To ensure precise placement of interstitial needles, we proposed a novel ultrasonic (US) probe calibration method to accurately register the US image in the magnetic resonance imaging (MRI) image and provide multimodal image guidance for needle placement. MethodsA wire-based calibration phantom combined with the stylus was developed for the calibration of US probe. The calibration phantom helps to quickly align the imaging plane of the US probe with the fiducial points to obtain US images of these points. The coordinates of fiducial points in US images were located automatically by feature extraction algorithms and were further corrected by the proposed correction method. Ingenious structures were designed on both sides of the calibration phantom to accurately obtain the coordinates of the fiducial points relative to the tracking device. Marker validation and pelvic phantom study were performed to evaluate the accuracy of the proposed calibration method. ResultsIn the marker validation, the US probe calibration method with corrected transformation achieves a registration accuracy of 0.694 ± 0.014 mm, and the uncorrected one is 0.746 ± 0.018 mm. In the pelvic phantom study, the needle tip difference was 1.096 ± 0.225 mm and trajectory difference was 1.416 ± 0.284 degrees. ConclusionThe proposed US probe calibration method is helpful to achieve more accurate multimodality image guidance for needle placement.

Percutaneous Radiologic Gastrostomy in Patients After Partial Gastrectomy: A Retrospective Study to Assess the Technical Feasibility of Postsurgical Remnant Stomach Access.

To evaluate the technical feasibility of percutaneous radiologic gastrostomy in patients after partial gastrectomy. This retrospective study included 15 consecutive gastrectomized patients with attempted percutaneous radiologic gastrostomy at our institution between April 2014 and March 2021. When the stomach was sufficiently insufflated to distend below the left anterior subcostal margin, percutaneous radiologic gastrostomy with gastropexy was conventionally performed by the Seldinger technique. When the stomach was still highly positioned and/or overlaid by the other organs, some adjunctive maneuvers, such as hydro-displacement, intragastric balloon support, or cephalad oblique puncture or left intercostal puncture, were employed as modified gastrostomy. Ultrasonography or x-ray or computed tomography fluoroscopy was used for imaging guidance during the gastric puncture. Adequate tube placement was defined as technical success. Technical details, clinical outcomes, and complications were reviewed. One patient underwent percutaneous radiologic jejunostomy instead of gastrostomy because safe gastric access could not be ensured. Seven patients underwent conventional gastrostomy; the other seven underwent modified gastrostomy with no gastropexy. The technical success rate was 100% (7/7) in the conventional group and 85.7% (6/7) in the modified group. The stomach was punctured under x-ray or computed tomography fluoroscopy for conventional gastrostomy. In contrast, the combination of various modalities was used for modified gastrostomy except for one failed case with unintentional transhepatic access. During a median follow-up of 108days, no major complications occurred. The adequate combination of multimodal imaging guidance and technical modifications could secure radiological creation of gastrostomy for the postsurgical stomach. Level 4, Case Series.

Apical closure device for full-percutaneous transapical structural and valve procedures with large-sized introducer sheaths: The final preclinical study.

Closed-chest transapical valve implantations (aortic, mitral, and tricuspid) and cardiac structural procedures requiring large-sized introducer sheaths cannot be safely performed with the available technology. We tested a self-expanding apical closure device in a closed-chest animal model, using large-sized introducer sheaths and human-sized animals to establish the technique for future tests in humans. Six human-sized pigs (mean weight: 89.7 ± 3.7 kg) received general anesthesia, intubation, and full heparinization (15,000 IU/animal; expected activated clotting time >200 s). Under fluoroscopy and multimodality imaging guidance with next-generation fusion imaging prototypes, a 15-cm long needle and a standard guidewire were percutaneously inserted under the xiphoidal aponeurosis and into the ventricular apex. After the exchange with a stiff guidewire, a 21-Fr introducer sheath for transapical procedures (outer diameter: 25-Fr) was placed in the left ventricle through the apex. The self-expanding closure device was inserted and deployed under fluoroscopic guidance while the 21-Fr sheath was gently removed. Hemodynamic conditions were monitored for 30 min and then the chest was opened to inspect the closure device and quantify the blood loss in the pericardium. Animals were killed and the hearts were removed and inspected. All six apical closure devices were successfully deployed without adverse events. No death, hemodynamic collapse, or cardiac tamponade occurred during the 30-minobservational period (mean systolic and diastolic pressures: 88 ± 11 and 58 ± 13 mmHg, respectively; mean heart rate: 60 ± 11 beats per minutes). Pre- and postdeployment (after protamine administration) mean activated clotting time was 541 ± 263 and 217 ± 62 s, respectively. The plugs provided good sealing with a mean of 27.2 ± 13.86 ml of blood lost in the pericardium. Postmortem inspection showed good plug fixation without myocardial damage. This self-expanding apical closure device successfully sealed the percutaneous access sites made with large-sized introducer sheaths in human-sized animals. This preclinical study suggests that transapical valve and structural procedures requiring large-sized introducer sheaths can be performed percutaneously.

Multimodal Intraoperative Image-Driven Surgery for Skull Base Chordomas and Chondrosarcomas.

Simple SummaryAchieving gross total resection during the first surgical intervention is particularly important for chondrosarcomas and chordomas, as recurrences are frequently impossible to resect due to post-surgical and post-radiation scarring and vascular fragility. Despite overall survival and progression-free survival being strongly dictated by gross total resection, it is reportedly achieved in less than 70% of patients. While the individual utility of several imaging modalities such as intraoperative CT, MRI, ultrasound, endoscopy, fluoroscopy and neuronavigation has already been demonstrated in previous literature; our case series highlights the importance and methodology of their simultaneous, real-time integration in the Advanced Multimodality Image-Guided Operating (AMIGO) suite at our institution to maximize of resection and mitigate complications.Given the difficulty and importance of achieving maximal resection in chordomas and chondrosarcomas, all available tools offered by modern neurosurgery are to be deployed for planning and resection of these complex lesions. As demonstrated by the review of our series of skull base chordoma and chondrosarcoma resections in the Advanced Multimodality Image-Guided Operating (AMIGO) suite, as well as by the recently published literature, we describe the use of advanced multimodality intraoperative imaging and neuronavigation as pivotal to successful radical resection of these skull base lesions while preventing and managing eventual complications.

Performance of an integrated multimodality image guidance and dose-planning system supporting tumor-targeted HDR brachytherapy for prostate cancer

Background and purposeAdvances in high-dose-rate brachytherapy to treat prostate cancer hinge on improved accuracy in navigation and targeting while optimizing a streamlined workflow. Multimodal image registration and electromagnetic (EM) tracking are two technologies integrated into a prototype system in the early phase of clinical evaluation. We aim to report on the system’s accuracy and workflow performance in support of tumor-targeted procedures. Materials and methodsIn a prospective study, we evaluated the system in 43 consecutive procedures after clinical deployment. We measured workflow efficiency and EM catheter reconstruction accuracy. We also evaluated the system’s MRI-TRUS registration accuracy with/without deformation, and with/without y-axis rotation for urethral alignment at initialization. ResultsThe cohort included 32 focal brachytherapy and 11 integrated boost whole-gland implants. Mean procedure time excluding dose delivery was 38 min (range: 21–83) for focal, and 56 min (range: 38–89) for whole-gland implants; stable over time. EM catheter reconstructions achieved a mean difference between computed and measured free-length of 0.8 mm (SD 0.8, no corrections performed), and mean axial manual corrections 1.3 mm (SD 0.7). EM also enabled the clinical use of a non or partially visible catheter in 21% of procedures. Registration accuracy improved with y-axis rotation for urethral alignment at initialization and with the elastic registration (mTRE 3.42 mm, SD 1.49). ConclusionThe system supported tumor-targeting and was implemented with no demonstrable learning curve. EM reconstruction errors were small, correctable, and improved with calibration and control of external distortion sources; increasing confidence in the use of partially visible catheters. Image registration errors remained despite rotational alignment and deformation, and should be carefully considered.

Tumor-self-targeted “thermoferroptosis-sensitization” magnetic nanodroplets for multimodal imaging-guided tumor-specific therapy

Ferroptosis-based nanomedicine has drawn increasing attention in antitumor therapy because of the advantages of this unconventional mode of apoptosis, but the difficulties of delivery to the tumor site and surface-to-core penetration after arrival seriously hinder further clinical transformation and application. Herein, we propose an unprecedented strategy of injecting magnetic nanodroplets (MNDs) to solve these two longstanding problems. MNDs are nanocarriers that can carry multifunctional drugs and imaging materials. MNDs can effectively accumulate in the tumor site by active tumor targeting (multifunctional drugs) and passive tumor targeting (enhanced permeability and retention effect), allowing diffusion of the MNDs from the surface to the core through mild-temperature magnetic fluid hyperthermia (MHT) under multimodal imaging guidance. Finally, the ferroptosis pathway is activated deep within the tumor site through the drug release. This approach was inspired by the ability of mild-temperature MHT to allow MNDs to quickly pass through the blood vessel-tumor barrier and deeply penetrate the tumor tissue from the surface to the core to amplify the antitumor efficacy of ferroptosis. This strategy is termed as “thermoferroptosis sensitization”. Importantly, this behavior can be performed under the guidance of multimodal imaging, making the design of MNDs for cancer therapy safer and more reasonable.

Sinus Venosus ASDs: Imaging and Percutaneous Closure

Percutaneous closure of sinus venosus atrial septal defects (ASD) using covered stent implantation is a new and promising minimally invasive technique. New imaging tools are used to ensure preoperative anatomical characterization and preoperative guidance, which are key procedural success factors. Here we will describe and analyze these recent developments. Sinus venosus ASDs present a wide variety of anatomical features which must be described and analyzed using various imaging tools, including 3D technology. Percutaneous closure is challenging, but can hasten clinical recovery compared to the gold-standard conventional open-heart surgery. The feasibility of percutaneous closure relies on precise preoperative anatomical study and on real-time guidance using a multimodal fusion imaging process. Three-dimensional modeling of sinus venosus ASD is essential to understand the large anatomical panel encountered in this pathology. Multimodal fusion imaging guidance is very useful for performing sinus venosus ASD percutaneous closure in selected patients.

Au nanostars@PDA@Fe3O4-based multifunctional nanoprobe for integrated tumor diagnosis and photothermal therapy

A multifunctional nanoprobe (based on Au nanostars@PDA@Fe3O4) is developed for tumor targeted imaging and targeted photothermal therapy. Au nanostars and Fe3O4 are connected with polydopamine, and combined with antibody-FITC or antibody-quantum dots for in vitro or in vivo fluorescence labeling (FL), respectively, to form the composite nanoprobe. The shape and lattice structure of Au nanostars and Fe3O4 were confirmed with TEM, HRTEM and XRD experiments. Compared with other Au nanoparticles@Fe3O4 composite probes, the Au nanostars@PDA@Fe3O4 structure has a low photothermal conversion threshold. Compared with the corresponding pure Au nanostars, the photothermal efficiency of the probe has increased by 50%, while maintaining 171% and 32% fluorescence enhancement in vitro and in vivo, respectively. Due to the charge transfer channel, the phonon emission of Au can go on in Fe3O4 via the PDA linking. Under the precise guidance of multimodal imaging, the nanoprobe conducts homogeneous photothermal ablation of bulky solid tumors (~ 400 mm3) in a xenograft mouse model. Animal model magnetic resonance imaging (MRI) results found that the MRI T2 signal intensity of the probe was 65% stronger than that of pure Fe3O4 nanoparticles. These results suggest that this nanoplatform is promising for integrated tumor diagnosis and targeted cancer therapy.

Construction of Smart Nanotheranostic Platform Bi-Ag@PVP: Multimodal CT/PA Imaging-Guided PDT/PTT for Cancer Therapy.

High-efficiency nanotheranostic agents with multimodal imaging guidance have attracted considerable interest in the field of cancer therapy. Herein, novel silver-decorated bismuth-based heterostructured polyvinyl pyrrolidone nanoparticles (NPs) with good biocompatibility (Bi-Ag@PVP NPs) were synthesized for accurate theranostic treatment, which can integrate computed tomography (CT)/photoacoustic (PA) imaging and photodynamic therapy/photothermal therapy (PDT/PTT) into one platform. The Bi-Ag@PVP NPs can enhance light absorption and achieve a better photothermal effect than bismuth NPs. Moreover, after irradiation under an 808 nm laser, the Bi-Ag@PVP NPs can efficiently induce the generation of reactive oxygen species (ROS), thereby synergizing PDT/PTT to exert an efficient tumor ablation effect both in vitro and in vivo. Furthermore, Bi-Ag@PVP NPs can also be employed to perform enhanced CT/PA imaging because of their high X-ray absorption attenuation and enhanced photothermal conversion. Thus, they can be utilized as a highly effective CT/PA imaging-guided nanotheranostic agent. In addition, an excellent antibacterial effect was achieved. After irradiation under an 808 nm laser, the Bi-Ag@PVP NPs can destroy the integrity of Escherichia coli, thereby inhibiting E. coli growth, which can minimize the risk of infection during cancer therapy. In conclusion, our study provides a novel nanotheranostic platform that can achieve CT/PA-guided PDT/PTT synergistic therapy and have potential antibacterial properties. Thus, this work provides an effective strategy for further broad clinical application prospects.

The Effect of Intravenous Thrombolysis on Transient Ischemic Attack and Cerebral Infarction Patients Under the Guidance of Multimodal Magnetic Resonance Imaging

Objective: To investigate the clinical effects of intravenous thrombolysis in the treatment of TIA (Transient Ischemic Attack) and cerebral infarction with multimodal MRI (magnetic resonance imaging), and to provide a reference for clinical diagnosis and treatment. Methods: Patients with acute cerebral infarction diagnosed and treated with intravenous thrombolysis were enrolled in the study. Multimodal MRI was performed to determine the location and type of cerebral infarction. Based on routine treatment and care, the rt-PA (Recombinant Tissue Plasminogen Activator) intravenous thrombolytic therapy was applied. The NIHSS (National Institutes of Health Stroke Scale) scores of patients before and after treatment were evaluated and compared to analyze the neurological prognosis. Results: The NIHSS scores after treatment were significantly lower than those before treatment, and the neurological prognosis was good. Three different forms of ACVS (asymmetric cortical venous signs) after treatment could be observed by SWI (drug-sensitive weighted imaging) images, which could help to assess the prognosis. Conclusion: Multimodal MRI could evaluate the type and severity of acute cerebral infarction. The rt-PA intravenous thrombolytic therapy could effectively promote the recovery of neurological functions in patients with cerebral infarction, which was worthy of clinical promotion.

Perfluorocarbon Nanodroplets with Deep Tumor Penetration and Controlled Drug Delivery for Ultrasound/Fluorescence Imaging Guided Breast Cancer Therapy.

Some impediments, including insufficient drug release, poor tumor penetration, and lack of real-time imaging guidance, still limited the therapeutic efficiency of nanotechnology-based drug delivery systems. Here, light-responsive perfluoropentane (PFP) based nanodroplets as doxorubicin (DOX) nanocarriers that could achieve deep tumor delivery under multimodal imaging guidance were developed. Triggered by laser irradiation, the liquid PFP with low boiling point could go through small-to-big size change and liquid-to-gas phase transformation. At the same time, the accompanied cavitation effect led to not only the disruption of dense extracellular matrix for deep penetration but also the disruption of endo-/lysosome for nucleus delivery of released DOX. Furthermore, different from many imaging approaches which were always "on", only upon laser stimulation could the nanodroplets act as ultrasound/fluorescence probes due to the echogenic PFP bubbles and the recovered fluorescence of DOX itself after released from nanodroplets, which was highly desirable to indicate the DOX state in real time. Therefore, such PFP nanodroplets with phase/size tunable properties enable site-specific drug delivery efficiently and exhibit their potent in cancer theranostics.