Experimental Investigation of Cryoneedle Heating during MR-Guided Cryoablation in Ex Vivo Tissue Samples at 1.5-Tesla

PurposeTo investigate cryoneedle heating risks during magnetic resonance (MR)-guided cryoablation and potential strategies to mitigate these risks.Materials and MethodsEx vivo experiments were performed on a 1.5-Tesla (T) MR scanner using an MR conditional cryoablation system on porcine tissue phantoms. Cryoneedles were placed inside the tissue phantom either with or without an angiocatheter. Typical cryoneedle geometric configurations (including gas supply line) encountered in clinical procedures with low to high expected heating risks were investigated. Up to 4 fiber optic temperature sensors were attached to the cryoneedle/angiocatheter to measure the MR-induced cryoneedle heating at different locations during MR with different estimated specific absorption rates (SARs). The impact of cryoneedle heating on cryoablation treatment was studied by comparing temperature changes during 10-min freeze-thaw cycles with and without MR.ResultsRapid temperature increases of >100 °C in < 2 minutes were observed during MR with a SAR of 2.1 W/kg. The temperature changes during a typical freeze-thaw cycle were also affected by cryoneedle heating when MR was used to monitor the ice-ball evolution. The observed cryoneedle heating was affected by multiple factors; including cryoneedle geometric configurations, sequence SAR, whether an angiocatheter was used, and whether the cryoneedle was connected to the rest of the cryoablation system.ConclusionsThe ex vivo experiments demonstrated that MR could induce significant cryoneedle heating risks. Furthermore, MR-induced cryoneedle heating can affect temperatures in the ice-ball evolution during the freeze-thaw cycle. Several practical strategies to reduce the cryoneedle heating have been proposed.     

Percutaneous MR Imaging–Guided Laser Ablation for the Treatment of Symptomatic Cervicofacial Vascular Malformations

PurposeTo evaluate the safety and effectiveness of percutaneous magnetic resonance (MR) imaging–guided laser ablation for the treatment of symptomatic soft tissue vascular malformations (VMs) in the face and neck.Materials and MethodsAn institutional review board–approved retrospective review was undertaken of all consecutive patients who underwent MR imaging–guided and monitored laser ablation for treatment of symptomatic, cervicofacial soft tissue VM. Preablation and postablation MR imaging findings were independently reviewed. Preablation and postablation VM sizes were documented. Preablation T2 signal characteristics and enhancement patterns as well as postablation change in both signal and enhancement were semiquantitatively assessed. Changes in VM size were compared using a paired t test.ResultsThirteen patients (women, 9; age, 14.5–69.5 years) with 13 VMs were treated for moderate-to-severe pain (n = 4), swelling/mass effect (n = 8), or predominantly cosmesis (n = 1) with 22 total ablation sessions. The baseline maximum VM diameter was 5.7 cm ± 4.2. At baseline, all VMs (100%) demonstrated variable T2-weighted signal hyperintensity and enhancement. For painful VM, the baseline pain score was 8 ± 1. Clinical follow-up was available for 10 patients. Of patients with available follow-up, 3 (100%) treated for moderate-to-severe pain and 7 (100%) treated for swelling/mass effect reported subjective complete or partial symptomatic relief. The patient treated predominantly for cosmetic reasons was lost to follow-up. Two patients (15.4%) experienced minor adverse events by the Society of Interventional Radiology standards. There were no major adverse events.ConclusionsMR imaging–guided and monitored percutaneous laser ablation is safe and effective for the treatment of symptomatic, cervicofacial VMs.     

MR Imaging–Based In Vivo Macrophage Imaging to Monitor Immune Response after Radiofrequency Ablation of the Liver

PurposeTo establish molecular magnetic resonance (MR) imaging instruments for in vivo characterization of the immune response to hepatic radiofrequency (RF) ablation using cell-specific immunoprobes.Materials and MethodsSeventy-two C57BL/6 wild-type mice underwent standardized hepatic RF ablation (70 °C for 5 minutes) to generate a coagulation area measuring 6–7 mm in diameter. CD68⁺ macrophage periablational infiltration was characterized with immunohistochemistry 24 hours, 72 hours, 7 days, and 14 days after ablation (n = 24). Twenty-one mice were subjected to a dose-escalation study with either 10, 15, 30, or 60 mg/kg of rhodamine-labeled superparamagnetic iron oxide nanoparticles (SPIONs) or 2.4, 1.2, or 0.6 mg/kg of gadolinium-160 (¹⁶⁰Gd)-labeled CD68 antibody for assessment of the optimal in vivo dose of contrast agent. MR imaging experiments included 9 mice, each receiving 10-mg/kg SPIONs to visualize phagocytes using T2¹-weighted imaging in a horizontal-bore 9.4-T MR imaging scanner, ¹⁶⁰Gd-CD68 for T1-weighted MR imaging of macrophages, or 0.1-mmol/kg intravenous gadoterate (control group). Radiological-pathological correlation included Prussian blue staining, rhodamine immunofluorescence, imaging mass cytometry, and immunohistochemistry.ResultsRF ablation–induced periablational infiltration (206.92 μm ± 12.2) of CD68⁺ macrophages peaked at 7 days after ablation (P < .01) compared with the untreated lobe. T2¹-weighted MR imaging with SPION contrast demonstrated curvilinear T2¹ signal in the transitional zone (TZ) (186 μm ± 16.9), corresponsing to Iron Prussian blue staining. T1-weighted MR imaging with ¹⁶⁰Gd-CD68 antibody showed curvilinear signal in the TZ (164 μm ± 3.6) corresponding to imaging mass cytometry.ConclusionsBoth SPION-enhanced T2¹-weighted and ¹⁶⁰Gd-enhanced T1-weighted MR imaging allow for in vivo monitoring of macrophages after RF ablation, demonstrating the feasibility of this model to investigate local immune responses.     

Intra-articular Injection of Bone Marrow Concentrate for Treatment of Patellofemoral Osteoarthritis: Preliminary Results Utilizing an Ultrasound-Guided Marrow Harvesting Technique

ObjectiveTo assess the effectiveness of intra-articular injection of bone marrow concentrate (BMC) under ultrasound (US) guidance in the treatment of patellofemoral osteoarthritis (OA), with clinical and volumetric magnetic resonance (MR) imaging follow-up.MethodsThis retrospective study included 96 consecutive patients referred for US-guided intra-articular injection of BMC for symptomatic patellofemoral OA for which conservative treatment had failed. A control group of 21 patients with symptomatic patellofemoral OA was included for comparison. Data on International Knee Documentation Committee (IKDC), Visual Analog Scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores as well as volumetric MR imaging (using T2 mapping sequence) were collected before and 12 months after injection, and the results were compared.ResultsNo technical adverse events were noted during bone marrow aspiration, BMC preparation, or intra-articular injection of BMC. No clinical adverse events were reported during long-term follow-up. All mean scores improved between baseline and 12 months after intra-articular injection of BMC (VAS 5.5 to 3.6, P < .0001; WOMAC 36.8 to 22.2, P < .0001; and IKDC 41.8 to 58.2, P < .0001). MR imaging at 1 year of follow-up after BMC treatment showed no statistically significant difference in hyaline cartilage volume compared with that at the baseline (P = .690), suggesting stabilization of the cartilage degradation process. In contrast, the group of untreated patients showed a significant decrease in the cartilage volume (P = .001), corresponding to a cartilage loss of 6.9%.ConclusionsThe results suggest that intra-articular injection of BMC under US guidance could be a promising option for the treatment of symptomatic patellofemoral OA and could promote the preservation of healthy residual cartilage volume.     

Radiofrequency Ablation of Facial Venolymphatic Malformations: Assessment of Efficacy and Safety and the Role of Injectable Electrodes

PurposeTo evaluate the efficacy and safety of ultrasound (US)-guided radiofrequency (RF) ablation in the treatment of facial microcystic lymphatic malformations (mLMs) or mixed venolymphatic malformations (VLMs) and to introduce the “induced-paralysis” technique with the use of an injectable electrode to minimize neural complications.Materials and MethodsData from patients with symptomatic facial mLMs or mixed VLMs who underwent US-guided RF ablation in 2014–2017 were retrospectively reviewed. Computed tomography (CT) and/or magnetic resonance (MR) imaging was used to localize any functional structures close to the target lesion. Treatment outcome was assessed by 4-point cosmetic grading score (CGS). Treatment outcome was compared between patients with vs without a functional structure close to the lesion and those treated with a noninjectable vs an injectable electrode. Immediate and late complications were assessed during follow-up.ResultsData from 15 patients were evaluated. Initial CGS and median volume were significantly decreased at the last follow-up in all patients (from 4 to 1 and from 7 mL to 0.7 mL, respectively; P < .05). Treatment outcome differed significantly between those with and without a functional structure on CT or MR imaging (P < .05) but showed no difference between noninjectable (n = 9) and injectable electrodes (n = 6). Two cases of transient cranial nerve palsy were seen in the noninjectable electrode group.ConclusionsUS-guided RF ablation is effective in patients with facial mLMs or mixed VLMs. The induced-paralysis technique with an injectable electrode has the potential to ensure technical safety without compromising efficacy.     

Percutaneous MR Imaging-Guided Laser Ablation and Cryoablation for the Treatment of Pediatric and Adult Symptomatic Peripheral Soft Tissue Vascular Anomalies

PurposeTo evaluate the safety and effectiveness of percutaneous magnetic resonance (MR) imaging-guided laser ablation and cryoablation for the treatment of symptomatic soft tissue vascular anomalies (VAs) of the trunk and extremities.Materials and MethodsAn institutional review board-approved retrospective review was undertaken of all pediatric and adult patients who underwent MR imaging-guided and monitored laser ablation and/or cryoablation for the treatment of symptomatic peripheral soft tissue VA. Preablation and postablation MR imaging was independently reviewed. Pain scores on the visual analog scale (0 to 10) and self-reported subjective symptomatic improvement were assessed. Change in VA size and pain scores were compared using a paired t test.ResultsThirty patients (24 females; age, 10–75 years) with 34 VAs were treated for moderate to severe pain (n = 27) or swelling/mass effect (n = 3) with 60 total ablation sessions. The baseline maximum VA diameter was 9.5 cm ± 8.6. At baseline, all VAs (100%) demonstrated variable T2-weighted signal hyperintensity and enhancement. The baseline pain score was 6.4 ± 1.6. Clinical follow-up was available for 23 patients. At a mean follow-up time of 12.2 months ± 10.1, 19 of 20 (95%) patients treated for pain and 2 of 3 (67%) patients treated for swelling/mass effect reported partial or complete symptomatic relief. There was a significant decrease in the postablation pain scores (−5.7 ± 1.0, P < .001) and maximum VA size (−2.3 cm ± 2.7, P = .004), with >50% reduction in VA T2 signal (59%) and enhancement (73%). Nine of 30 (30%) patients experienced minor complications.ConclusionsMR imaging-guided and monitored percutaneous laser ablation and cryoablation appear to be safe and effective for the treatment of symptomatic peripheral soft tissue VAs.     

Early Results of Unilateral Prostatic Artery Embolization as a Focal Therapy in Patients with Prostate Cancer under Active Surveillance: Cancer Prostate Embolisation,a Pilot Study

PurposeTo evaluate the feasibility of prostatic artery embolization in patients with low-risk prostate cancer (PC) under active surveillance (AS).MethodsThis monocentric prospective pilot study, running from June 2018 to June 2019, included 10 patients with low-risk PC under AS, median age 72 years (range, 62–77 years), with a unilateral focal lesion visible on magnetic resonance (MR) imaging, with Prostate Imaging Reporting and Data System v2 score ≥3/5 confirmed by multiparametric MR imaging-targeted biopsy and Gleason score 6. The patients underwent unilateral prostatic artery embolization with 300–500 μm Embospheres in the affected prostatic lobe. The primary endpoint was technical feasibility (prostate and no off-target ischemia in the imaging). The secondary endpoints included safety, negative biopsies/MR imaging response/functional outcomes at 6 months, and oncologic efficacy at 1 year.ResultsEmbolization was successfully achieved in all patients; prostate ischemia was confirmed on multiparametric MR imaging, and no off-target ischemia was reported. No major complications were reported. Four patients (40%) presented with both negative targeted and systematic biopsies at 6 months. No lesions were seen on the MR imaging in 30% of patients. The mean International Prostate Symptom Score and International Index of Erectile Function score were 7 and 19 and 5 and 20 at baseline and 6 months, respectively, with no significant difference. Nine patients (90%) were still under AS at 1 year. One patient (10%) had PC progression outside the target lesion and was switched over to curative radiotherapy.ConclusionsProstatic artery embolization is feasible and appears safe for prostate cancer patients under AS, with no impact on erectile function or continence status. These results justify the pursuit of further studies.     

Mechanochemical Endovenous Ablation of Varicose Veins in Pediatric Patients with Klippel-Trénaunay Syndrome: Feasibility,Safety, and Initial Results

PurposeTo evaluate feasibility, safety, and results of endovenous mechanochemical ablation (MOCA) for treatment of persistent embryonic and dysplastic veins in pediatric patients with Klippel-Trénaunay syndrome (KTS).Materials and MethodsThirteen MOCA procedures were performed in 11 patients (age range, 4–16 years) with KTS and symptomatic persistent embryonic or dysplastic veins during a 24-month period. All patients were evaluated with color Doppler (CD) ultrasound (US), contrast-enhanced MR imaging, and venography to assess the anatomy of the target vessels and patency of the deep venous system. All procedures were performed under general anesthesia with a ClariVein catheter and liquid sodium tetradecyl sulfate as the sclerosing agent. US and fluoroscopic guidance were used in all cases. Technical success rate, primary occlusion rate, adverse effects, and recanalization rates were evaluated. Clinical and radiological (CD US) controls were performed 1 day, 7 days, 1 month, and 6 months after the procedure and once a year thereafter, with a mean follow-up of 16 months (range, 6–25 months).ResultsTechnical success and primary occlusion were achieved in all patients with no adverse events. During the follow-up period, CD US demonstrated partial recanalization and symptom recurrence in 2 patients (18%), 14 and 18 months after the initial procedure. These 2 patients had a second ablation procedure with no recanalization or symptom recurrence during the subsequent follow-up period.ConclusionsMOCA is feasible and appears to be a safe and effective technique for treatment of varicose veins in pediatric patients with KTS.     

Detection of metallic objects on digital radiographs with convolutional neural networks: A MRI screening tool

IntroductionScreening for metallic implants and foreign bodies before magnetic resonance imaging (MRI) examinations, are crucial for patient safety. History of health are supplied by the patient, a family member, screening of electronic health records or the picture and archive systems (PACS). PACS securely store and transmits digital radiographs (DR) and related reports with patient information. Convolutional neural networks (CNN) can be used to detect metallic objects in DRs stored in PACS. This study evaluates the accuracy of CNNs in the detection of metallic objects on DRs as an MRI screening tool.MethodsThe musculoskeletal radiographs (MURA) dataset consisting of 14.863 upper extremity studies were stratified into datasets with and without metal. For each anatomical region: Elbow, finger, hand, humerus, forearm, shoulder and wrist we trained and validated CNN algorithms to classify radiographs with and without metal. Algorithm performance was evaluated with area under the receiver-operating curve (AUC), sensitivity, specificity, predictive values and accuracies compared with a reference standard of manually labelling.ResultsSensitivities, specificities and area under the ROC-curves (AUC) for the six anatomic regions ranged from 85.33% (95% CI: 78.64%–90.57%) to 100.00% (95% CI: 98.16%–100.00%), 75.44% (95% CI: 62.24%–85.87%) to 93.57% (95% CI: 88.78%–96.75%) and 0.95 to 0.99, respectively.ConclusionCNN algorithms classify DRs with metallic objects for six different anatomic regions with near-perfect accuracy. The rapid and iterative capability of the algorithms allows for scalable expansion and as a substitute MRI screening tool for metallic objects.Implications for practiceAll CNNs would be able to assist in metal detection of digital radiographs prior to MRI, an substantially decrease screening time.     

MR Imaging Enables Real-Time Monitoring of In Vitro Electrolytic Ablation of Hepatocellular Carcinoma

PurposeTo evaluate the capability of T2-weighted magnetic resonance (MR) imaging to monitor electrolytic ablation-induced cell death in real time.Materials and MethodsAgarose phantoms arranged as an electrolytic cell were exposed to varying quantities of electric charge under constant current to create a pH series. The pH phantoms were subjected to T2-weighted imaging with region of interest quantitation of the acquired signal intensity. Subsequently, hepatocellular carcinoma (HCC) cells encapsulated in an agarose gel matrix were subjected to 10 V of electrolytic ablation for variable lengths of time with and without concurrent T2-weighted MR imaging. Cellular death was confirmed by a fluorescent reporter. Finally, to confirm that real-time MR images corresponded to ablation zones, 10 V electrolytic ablations were performed followed by the addition of pH-neutralizing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer.ResultsAnalysis of MR imaging from agarose gel pH phantoms demonstrated a relationship between signal intensity and pH at the anodes and cathodes. The steep negative phase of the anode model (pH < 3.55) and global minimum of the cathode model (pH ≈ 11.62) closely approximated established cytotoxic pH levels. T2-weighted MR imaging demonstrated a strong correlation of ablation zones with regions of HCC cell death (r = 0.986; R² = 0.916; P < .0001). The addition of HEPES buffer to the hydrogel resulted in complete obliteration of MR imaging-observed ablation zones, confirming that change in pH directly caused the observed signal intensity attenuation of the ablation zone.ConclusionsT2-weighted MR imaging enabled the real-time detection of electrolytic ablation zones, demonstrating a strong correlation with histologic cell death.     

Adverse events due to unnecessary radiation exposure in medical imaging reported in Finland

IntroductionAdverse events in radiology are quite rare, but they do occur. Radiation safety regulations and the law obligate organizations to report certain adverse events, harm and near misses, especially events related to patients' health and safety. The aim of this study was to describe and analyse incidents related to radiation safety issues reported in Finland.MethodsThe data were collected from incident reports documented by radiology personnel concerning notifications of abnormal events in medical imaging made to the Radiation and Nuclear Safety Authority between 2010 and 2017. During these eight years, 312 reports were submitted. Only events reported from radiology departments were included; nuclear medicine, radiotherapy and animal radiology cases were excluded. The final number of reports was 293 (94%).ResultsThe majority of the 293 approved reports were related to computed tomography (CT, 68.3%) and to X-ray examinations (27.6%). Altogether 82.9% of those irradiated were adults, most of whom were exposed to unnecessary radiation through CT (86.5%), 5.5% were children, and 4.4% pregnant women. The most common effective dose of unnecessary radiation was 1 mSv or less (89.7% of all examinations). The highest effective doses were reported in CT (from under 1 mSv–20 mSv and above). The reasons for the adverse events were incorrect identification (32%), incorrect procedure, site or side (30%); and human errors or errors of knowledge (20%).ConclusionAdverse events occurred especially in CT examinations. It is important to collect and analyse incident data, assess the harmful events, learn from them and aim to reduce adverse events.Implications for practiceThis study emphasizes the need for radiological personnel to obtain evidence-based information on adverse events and focus on training to improve patient safety.     

Evaluation of optimised 3D turbo spin echo and gradient echo MR pulse sequences of the knee at 3T and 1.5T

IntroductionTo investigate the impact of parameter optimisation for novel three-dimensional 3D sequences at 1.5T and 3T on resultant image quality.MethodsFollowing institutional review board approval and acquisition of informed consent, MR phantom and knee joint imaging on healthy volunteers (n = 16) was performed with 1.5 and 3T MRI scanners, respectively incorporating 8- and 15-channel phased array knee radiofrequency coils. The MR phantom and healthy volunteers were prospectively scanned over a six-week period. Acquired sequences included standard two-dimensional (2D) turbo spin echo (TSE) and novel three-dimensional (3D) TSE PDW (SPACE) both with and without fat-suppression, and T21W gradient echo (TrueFISP) sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured for knee anatomical structures. Two musculoskeletal radiologists evaluated anatomical structure visualisation and image quality. Quantitative and qualitative findings were investigated for differences using Friedman tests. Inter- and intra-observer agreements were determined with κ statistics.ResultsPhantom and healthy volunteer images revealed higher SNR for sequences acquired at 3T (p-value <0.05). Generally, the qualitative findings ranked images acquired at 3T higher than corresponding images acquired at 1.5T (p < 0.05). 3D image data sets demonstrated less sensitivity to partial volume averaging artefact (PVA) compared to 2D sequences. Inter- and intra-observer agreements for evaluation across all sequences ranged from 0.61 to 0.79 and 0.71 to 0.92, respectively.ConclusionBoth 2D and 3D images demonstrated higher image quality at 3T than at 1.5T. Optimised 3D sequences performed better than the standard 2D PDW TSE sequence for contrast resolution between cartilage and joint fluid, with reduced PVA artefact.Implications for practiceWith rapid advances in MRI scanner technology, including hardware and software, the optimisation of 3D MR pulse sequences to reduce scan time while maintaining image quality, will improve diagnostic accuracy and patient management in musculoskeletal MRI.     

Yttrium-90 Radioembolization to the Prostate Gland: Proof of Concept in a Canine Model and Clinical Translation

PurposeTo investigate the feasibility, safety, and absorbed-dose distribution of prostatic artery radioembolization (RE) in a canine model.Materials and MethodsFourteen male castrated beagles received dihydroandrosterone/estradiol to induce prostatic hyperplasia for the duration of the study. Each dog underwent fluoroscopic prostatic artery catheterization. Yttrium-90 (⁹⁰Y) microspheres (TheraSphere; Boston Scientific, Marlborough, Massachusetts) were delivered to 1 prostatic hemigland (dose escalation from 60 to 200 Gy), with the contralateral side serving as a control. Assessments for adverse events were performed throughout the follow-up (Common Terminology Criteria for Adverse Events v5.0). Positron emission tomography/magnetic resonance (MR) imaging provided a confirmation after the delivery of absorbed-dose distribution. MR imaging was performed before and 3, 20, and 40 days after RE. Tissue harvest of the prostate, rectum, bladder, urethra, penis, and neurovascular bundles was performed 60 days after RE.ResultsAll the animals successfully underwent RE. Positron emission tomography/MR imaging demonstrated localization to and good coverage of only the treated hemigland. No adverse events occurred. The MR imaging showed a significant dose-dependent decrease in the treated hemigland size at 40 days (25%–60%, P < .001). No extraprostatic radiographic changes were observed. Necropsy demonstrated no gross rectal, urethral, penile, or bladder changes. Histology revealed RE-induced changes in the treated prostatic tissues of the highest dose group, with gland atrophy and focal necrosis. No extraprostatic RE-related histologic findings were observed.ConclusionsProstate ⁹⁰Y RE is safe and feasible in a canine model and leads to focal dose-dependent changes in the gland without inducing unwanted extraprostatic effects. These results suggest that an investigation of nonoperative prostate cancer is warranted.     

Dual-Applicator MR Imaging–Guided Microwave Ablation with Real-Time MR Thermometry: Phantom and Porcine Tissue Model Experiments

PurposeTo investigate the effect of simultaneous use of dual applicators on the image quality of real-time magnetic resonance (MR) thermometry and to characterize the dual-applicator treatment zone pattern during MR imaging–guided microwave ablation (MWA).Materials and MethodsMWA experiments were performed on a 1.5-T MR scanner with 2 commercial microwave systems (902–928 MHz). Phantom experiments were first performed to evaluate the effect of dual-applicator MWA on the image quality of MR. Then, porcine tissue model experiments were conducted with real-time MR thermometry using either a single applicator or dual applicators inserted 2.6, 3.6, and 4.6 cm apart. Fiberoptic thermal probes were used to measure the temperature changes at the tissue surface.ResultsSimultaneous use of dual applicators resulted in a decrease in the relative signal-to-noise ratio (SNR) in the MR thermometry images to 55% ± 2.9% when compared with that of a single applicator (86.2% ± 2.0%). Despite the lower SNR, the temperature and ablation zone maps were of adequate quality to allow visualization of the ablation zone(s). The extents of increase in the temperature at the tissue surface using dual applicators (19.7 °C ± 2.6 °C) and a single applicator (18.2 °C ± 3.3 °C) were not significantly different (P = .40). Treatment zones were significantly larger (P < .05) in dual-applicator ablations (29.4 ± 0.4, 39.9 ± 0.6, and 42.6 ± 0.9 cm² with 2.6-, 3.6-, and 4.6-cm spacing, respectively) at the end of the ablation procedure than in the single-applicator MWA (18.6 ± 0.9 cm²).ConclusionsMR imaging–guided dual-applicator MWA produced larger ablation zones while allowing adequate real-time MR thermometry image quality for monitoring the evolution of the treatment zone.     

Robot-Assisted Transarterial Chemoembolization of Hepatocellular Carcinoma Using a Coaxial Microcatheter Driving Controller-Responder Robot System: Clinical Pilot Study

PurposeTo evaluate the feasibility and safety of robot-assisted transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) using a new coaxial microcatheter driving controller-responder robot (CRR) system.Materials and MethodsA single-center prospective pilot study approved by the institutional review board was conducted using this CRR developed after analyzing 20 cases of conventional TACE procedures from May to October 2021. The study included 10 patients with HCCs: 5 (median age, 72 years; range, 64–73 years) underwent robot-assisted TACE, and 5 (median age, 57 years; range, 44–76 years) underwent conventional TACE for comparison. The feasibility and safety of robot-assisted TACE were evaluated by assessing the technical success, procedure time, adverse event rate, radiation dose, and early tumor response.ResultsThe entire TACE procedure was divided into 30 steps, of which 8 could be robotized. In robot-assisted TACE, technical success was achieved in 4 (80%) of 5 patients. No procedure-related adverse event was observed. The median procedure time was 56 minutes. At the 1-month follow-up, 3 of the 4 patients showed a complete or partial response after robot-assisted TACE. The median radiation doses for the operator and patients were 0.4 and 2,167.5 μSv in robot-assisted TACE and 53.2 and 2,989.7 μSv in conventional TACE, respectively.ConclusionsRobot-assisted TACE using a new CRR system was feasible and safe for the treatment of HCC and could remarkably decrease radiation exposure for the operators.     

Sodium Cholate Bile Acid-Stabilized Ferumoxytol-Doxorubicin-Lipiodol Emulsion for Transcatheter Arterial Chemoembolization of Hepatocellular Carcinoma

PurposeTo develop bile acid-stabilized multimodal magnetic resonance (MR) imaging and computed tomography (CT)-visible doxorubicin eluting lipiodol emulsion for transarterial chemoembolization of hepatocellular carcinoma (HCC).Materials and MethodsFerumoxytol, a US Food and Drug Administration-approved iron oxide nanoparticle visible under MR imaging was electrostatically complexed with doxorubicin (DOX). An amphiphilic bile acid, sodium cholate (SC), was used to form a stable dispersion of ferumoxytol-DOX complex in lipiodol emulsion. Properties of the fabricated emulsion were characterized in various component ratios. Release kinetics of DOX were evaluated for the chemoembolization applications. Finally, in vivo multimodal MR imaging/CT imaging properties and potential therapeutic effects upon intra-arterial (IA) infusion bile acid-stabilized ferumoxytol-DOX-lipiodol emulsion were evaluated in orthotopic McA-Rh7777 HCC rat models.ResultsDOX complexed with ferumoxytol through electrostatic interaction. Amphiphilic SC bile acid at the interface between the aqueous ferumoxytol-DOX complexes and lipiodol enabled a sustained DOX release (17.2 ± 1.6% at 24 hours) at an optimized component ratio. In McA Rh7777 rat HCC model, IA-infused emulsion showed a significant contrast around tumor in both T2-weighted MR imaging and CT images (P = .044). Hematoxylin and eosin and Prussian blue staining confirmed the local deposition of IA-infused SC bile acid-stabilized emulsion in the tumor. The deposited emulsion induced significant increases in TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) stain-positive cancer cell apoptosis compared to those in a group treated with the nonstabilized emulsion.ConclusionsSC bile acid-stabilized ferumoxytol-DOX-lipiodol emulsion demonstrated sustained drug release and multimodal MR imaging/CT imaging capabilities. The new lipiodol-based formulation may enhance the therapeutic efficacy of chemoembolization in HCC.     

Endovascular Celiac Denervation for Glycemic Control in Patients with Type 2 Diabetes Mellitus

PurposeTo investigate the safety and efficacy of catheter-based endovascular denervation (EDN) at the celiac artery and abdominal aorta around the celiac artery on glycemic control in patients with type 2 diabetes mellitus (T2DM).Materials and MethodsWith a novel catheter system, EDN was conducted at the celiac artery along with the abdominal aorta around the celiac artery in patients with T2DM whose glycosylated hemoglobin (HbA1c) level was >7.5%. The primary outcome was HbA1c level at 6 months. Other outcomes included safety, oral glucose tolerance test, homeostasis model assessment of insulin resistance (HOMA-IR), fasting plasma glucose (FPG) level, 2-hour postprandial plasma glucose (2hPG) level, and C-peptide test.ResultsA total of 11 subjects were included for analysis. The technical success was 100%, and no severe treatment-related adverse events or major complications were observed. Both HbA1c level and HOMA-IR were significantly reduced at 6 months (9.9% vs 8.0%, P = .005; 13.3 vs 6.0, P = .016). Decreases in FPG and 2hPG levels were observed (227.2 vs 181.8 mg/dL, P < .001; 322.2 vs 205.2 mg/dL, P = .001). The C-peptide test indicated improved β-cell function (area under the curve, 0.23 vs 0.28 pmol/mL, P = .046). A reduction of daily insulin injection (P = .02) and improvement of liver function (alanine aminotransferase, P = .014; γ-glutamyl transpeptidase, P = .021) were also observed.ConclusionsEDN in the celiac artery and abdominal aorta around the celiac artery elicited a clinically significant improvement in glycemic control and insulin resistance in patients with T2DM, with good tolerability as demonstrated by 6-month follow-up.     

Multicenter Experience with the Surfacer Inside-Out Access Catheter System in Patients with Thoracic Venous Obstruction: Results from the SAVE Registry

PurposeTo report the device performance and safety for the Surfacer Inside-Out access catheter system in patients with thoracic central venous obstruction (TCVO) requiring central venous access (CVA).Materials and MethodsFive sites prospectively enrolled 30 patients requiring a tunneled dialysis catheter between February 2017 and September 2018 in the SAVE (Surfacer System to Facilitate Access in Venous Obstructions) registry. Patient demographics, medical history, and type of TCVO were documented at enrollment. Device performance and adverse events were collected during the procedure and upon hospital discharge. Twenty-nine of the 30 patients enrolled required CVA for hemodialysis. Retrospective classification of TCVOs according to SIR reporting standards showed 9 patients (30%) had Type 4 obstructions, 8 (26.7%) had Type 3, 5 (16.7%) had Type 2, and 8 (26.7%) had Type 1 obstruction.ResultsCentral venous catheters (CVCs) were successfully placed in 29 of 30 patients (96.7%). The procedure was discontinued in 1 patient due to vascular anatomical tortuosity. All 29 patients with successful CVC placement achieved adequate catheter patency and tip positioning. There were no device-related adverse events, catheter malposition, or intra- or postprocedural complications. Mean time from device insertion to removal for the 29 patients who successfully completed the procedure was 24 ± 14.9 (range, 6–70) minutes. Mean fluoroscopy time was 6.8 ± 4.5 (range, 2.2–25.5) minutes.ConclusionsThe Surfacer Inside-Out procedure provided an alternative option to restore right-sided CVA in patients with TCVO.     

Clinical Safety and Efficacy of Locoregional Therapy Combined with Adoptive Transfer of Allogeneic γδ T Cells for Advanced Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

PurposeTo investigate the safety and efficacy of locoregional therapy plus adoptive transfer of allogeneic gamma delta (γδ) T cells for patients with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC).MethodsThirty patients with HCC and 29 patients with ICC were randomly assigned to receive locoregional therapy (HCC, Group A, n = 15; ICC, Group C, n = 15) or locoregional therapy plus γδ T cell therapy (HCC, Group B, n = 15; ICC, Group D, n = 14). Groups A and C only received locoregional ablation (cryoablation or irreversible electroporation), whereas Groups B and D received locoregional therapy followed by adoptive transfer of allogeneic γδ T cells. The primary endpoints were safety, distant progression-free survival (PFS), local PFS, and overall survival (OS).ResultsThe median distant PFS was significantly longer in the combined treatment groups than the locoregional treatment groups (HCC: 8 vs 4 months, P = .04; ICC: 8 vs 4 months, P = .021). There was no significant difference in local PFS between the 2 treatment modalities. Patients with HCC in the combined treatment group had a longer OS (median OS: 13 vs 8 months, P = .029). However, there was no significant difference in OS in patients with ICC between the 2 treatment modalities (median OS: 9.5 vs 8 months, P = .546). All adverse events were manageable with no significant difference in incidence between groups.ConclusionsThe novel combination of locoregional ablation with adoptive transfer of allogeneic γδ cells was safe, with encouraging clinical efficacy against HCC and ICC.     

MR Features of Juxta-Articular Venous Malformations of the Knee to Predict the Clinical Outcome of Sclerotherapy

PurposeTo analyze and correlate preinterventional magnetic resonance (MR) imaging findings with clinical symptoms after percutaneous sclerotherapy of venous malformations (VMs) adjacent to the knee.Materials and MethodsTwenty-five patients (mean age, 24 y; range, 7–55 y; 11 female) with 26 VMs adjacent to the knee undergoing sclerotherapy (direct puncture, diagnostic angiography, sclerosant injection) were identified, and MR imaging findings were analyzed. The VM involved the synovium of the knee joint in 19 of 26 cases (76%). These lesions were associated with joint effusion (3 of 19; 16%), hemarthrosis (4 of 19; 21%), or synovial thickening (16 of 19; 84%). Follow-up ended 6–8 weeks after the first or second sclerotherapy session if complete pain relief was achieved or 3 months after the third sclerotherapy session. Treatment outcomes were categorized as symptom improvement (complete or partial pain relief) or poor response (unchanged or increased pain).ResultsForty-nine percutaneous sclerotherapy sessions were performed. Despite the absence of signs of knee osteoarthritis, patients with a VM involving the synovium (8 of 14; 57%) showed a poor response to sclerotherapy (1 of 8 [13%] pain-free after 1 sclerotherapy session). Among patients with VMs with no associated joint alteration and no synovial involvement (6 of 14; 43%), 5 of 6 (83%) showed improvement of symptoms after 1 sclerotherapy session (P < .05).ConclusionsJuxta-articular VMs of the knee are frequently associated with hemarthrosis and synovial thickening. Patients with signs of osteoarthritis and synovial involvement of the VM on presclerotherapy MR imaging deserve special consideration, as these findings predict worse clinical symptoms after sclerotherapy.