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.     

The Value of Preprocedural MR Imaging in Genicular Artery Embolization for Patients with Osteoarthritic Knee Pain

PurposeTo determine the value of preprocedural MR imaging in genicular artery embolization (GAE) for patients with osteoarthritic knee pain.Materials and MethodsThis single-center study retrospectively analyzed 28 knees in 18 patients who underwent GAE for intractable knee pain < 1 month after MR imaging. The pain experienced in each knee was evaluated on a 100-mm visual analog scale (VAS) at baseline and 1- and 3-month after GAE. “GAE responders” were defined as knees that exhibited greater than 30% reduction of VAS pain scores from baseline at both follow-up visits. Musculoskeletal radiologists evaluated MR images of the affected knee compartment regarding cartilage defects, osteophytes, subchondral cysts, bone marrow lesions (BMLs), meniscal injury, and joint effusion. The performances of Kellgren–Lawrence (KL) grading and MR findings in predicting GAE responders was estimated based on receiver operating characteristic curves.ResultsThe mean VAS pain score was 84.3 mm. BML (area under the curve [AUC], 0.860; P < .001), meniscal injury (AUC, 0.811; P = .003), and KL grading (AUC, 0.898; P < .001) were significantly associated with GAE outcome. To predict GAE responders, KL grade ≤ 2 yielded a sensitivity of 87.5% and a specificity of 60.9%, BML grade ≤ 1 yielded a sensitivity of 75.0% and a specificity of 69.6%, and meniscal injury grade ≤ 2 yielded a sensitivity of 83.3% and a specificity of 72.7%.ConclusionsLarge BMLs and severe meniscal injuries on MR imaging, as well as high KL grades, indicated poor responses to GAE.     

Factors Affecting Adverse Events after Venous Malformation Sclerotherapy

PurposeTo evaluate factors that contribute to adverse events (AEs) after embolization of venous malformations (VMs) using sclerosing agents.Materials and MethodsA retrospective review of patients who underwent direct puncture embolization of VMs with a sclerosing agent and adjunctive techniques, also termed as sclerotherapy, from 2016 to 2021 was performed. Three-hundred one embolizations in 137 patients (median age, 19.0 years; interquartile range, 12.8–31.5 years) were evaluated. The VM characteristics and embolization details were analyzed. Anticoagulation was also evaluated based on D-dimer levels. Cutaneous and noncutaneous AEs were analyzed. The AEs were categorized using Society of Interventional Radiology guidelines.ResultsVMs involving tissue planes were subcutaneous (n = 104), intramuscular (n = 84), and combined (n = 113). Overlying skin involvement was observed in 56% of the patients. Sodium tetradecyl sulfate was mainly used (83%). Periprocedural anticoagulation was used in 9% of the patients. Most AEs were minor (30/301, 9.7%), and only 1.7% (5/301) were major (21 cutaneous and 14 noncutaneous AEs). Age below 18 years (odds ratio, 4.4502; 95% confidence interval, 1.5607–12.6890; P = .0052) and overlying skin involvement (odds ratio, 7.1794; 95% confidence interval, 1.6226–31.7656; P = .0094) were factors associated with cutaneous AEs. All noncutaneous AEs developed in patients with intramuscular VMs; however, this association was not statistically significant. There was no severe hematologic AE or permanent consequence.ConclusionsThe overall AE rate after VM embolization was 11.6%; however, major AEs were rare (1.7%). Cutaneous AEs were associated with young age and overlying skin involvement. All noncutaneous AEs developed in patients with intramuscular VMs.     

Assessing the Effects of Geniculate Artery Embolization in a Nonsurgical Animal Model of Osteoarthritis

PurposeTo create a nonsurgical animal model of osteoarthritis (OA) to evaluate the effects of embolotherapy during geniculate artery embolization (GAE).Materials and MethodsFluoroscopy-guided injections of 700 mg of sodium monoiodoacetate were performed into the left stifle in 6 rams. Kinematic data were collected before and after induction. At 10 weeks after induction, Subjects 1 and 4–6 underwent magnetic resonance (MR) imaging with dynamic contrast enhancement (DCE) and Subjects 1, 3, and 4–6 underwent angiography with angiographic scoring to identify regions with greatest disease severity for superselective embolization (75–250-μm microspheres). Target vessel size was measured. At 24 weeks after angiography, DCE-MR imaging, angiography, and euthanasia were performed, and bilateral stifles were harvested. Medial/lateral tibial and femoral condylar, patellar, and synovial samples were cut, preserved, decalcified, and scored using the Osteoarthritis Research Society International criteria. The stifle and synovium Whole-Organ Magnetic Resonance Imaging Score and Multicenter Osteoarthritis Study score were determined. The volume transfer constant (K_trans) and extracellular volume fraction (v_e) were calculated from DCE-MR imaging along the lateral synovial regions of interest.ResultsThe mean gross and microscopic pathological scores were elevated at 38 and 61, respectively. Mean synovitis score was elevated at 9.2. Mean pre-embolization and postembolization angiographic scores were 5 and 3.8, respectively. Mean superior, transverse, and inferior geniculate artery diameters were 3.1 mm ± 1.21, 2.0 mm ± 0.50, and 1.6 mm ± 0.41 mm, respectively. Mean pre-embolization and postembolization cartilage and synovitis scores were elevated at 35.13 and 73.3 and 5.5 and 9.2, respectively. The K_trans/v_e values of Subjects 4, 5, and 6 were elevated at 0.049/0.38, 0.074/0.53, and 0.065/0.51, respectively. Altered gait of the hind limb was observed in all subjects after induction, with reduced joint mobility. No skin necrosis or osteonecrosis was observed.ConclusionsA nonsurgical ovine animal knee OA model was created, which allowed the collection of angiographic, histopathological, MR imaging, and kinematic data to study the effects of GAE.     

Cryoablation of Venous Malformations: A Systematic Review

This study aimed to review systematically the efficacy, safety, and technical aspects of cryoablation in the treatment of venous malformations (VMs) and to provide the groundwork for future studies. A literature search for clinical studies utilizing percutaneous cryoablation of VMs was performed. All clinical studies related to primary or secondary treatment of VMs with percutaneous cryoablation were included in this review. These selected studies were evaluated for patient characteristics, cryoablation technique, technical success, lesion size and pain scores before and after cryoablation, and adverse outcomes. Random effects analysis of postprocedural changes in lesion volume and pain scores was performed. There were 54 patients with 55 cases of cryoablation of VMs. Of these cases, 27 recorded changes in lesion volume and 31 recorded changes in pain scores. The weighted mean postprocedural decrease in lesion size was 92.0% (raw average, 71.7%). The weighted mean reduction in pain score was 77% (raw average, 78.2%). Considering all treated cases (55), complete resolution of symptoms was seen in 35 cases (63.6%) and overall (complete or partial) improvement in 52 cases (94.5%). Common postprocedural symptoms included pain, bruising, swelling and numbness lasting less than 2 weeks. There were two major adverse events (3.7%), with both cases due to persistent dysesthesia. Patients with a history of prior sclerotherapy demonstrated lower preprocedural and postprocedural pain scores (4.7 and 1.3) than patients without prior treatments (5.8 and 2.8). Cryoablation of VMs appears to be potentially safe and effective on limited short-interval follow-up.     

Genicular Artery Embolization for Refractory Hemarthrosis following Total Knee Arthroplasty: Technique,Safety, Efficacy,and Patient-Reported Outcomes

PurposeTo investigate the safety and efficacy of genicular artery embolization for treatment of refractory hemarthrosis following total knee arthroplasty.Material and MethodsPatients who underwent genicular artery embolization with spherical embolics between January 2010 and March 2020 at a single institution were included if they had undergone total knee arthroplasty and subsequently experienced recurrent hemarthrosis. Technical success was defined as the significant reduction or elimination of the hyperemic blush. Clinical success was defined as the absence of clinical evidence of further hemarthrosis. Clinical follow-up was performed 7–14 days after the procedure and at 3-month intervals thereafter via a telephone interview. A total of 117 embolizations, comprising 82 initial, 28 first repeat, and 7 second repeat, were performed.ResultsAn average of 2.5 arteries was treated per procedure. The superior lateral genicular artery was the most frequently embolized. The most utilized embolic size was 100–300 μm. Follow-up was available for all patients, with a median duration of 21.5 months. 65.9%, 25.6%, and 8.5% of patients underwent 1, 2, and 3 treatments, respectively. Complications occurred following 12.8% of treatments, of which the most common was transient cutaneous ischemia. Technical success was achieved in all cases. Clinical success was achieved in 56%, 79%, and 85% of patients following the first, second, and third treatment, respectively. 83% of patients reported being either satisfied or very satisfied with the overall result.ConclusionsTargeted genicular artery embolization with spherical embolics is an effective treatment for recurrent hemarthrosis with infrequent serious complications. Repeat embolization should be considered in cases of recurrence following initial therapy.     

Association between Baseline Osteoarthritic Features on MR Imaging and Clinical Outcome after Genicular Artery Embolization for Knee Osteoarthritis

PurposeTo explore the association between baseline osteoarthritis (OA)-related magnetic resonance (MR) imaging features and pain reduction after genicular artery embolization (GAE) in patients with mild-to-moderate symptomatic knee OA resistant to conservative therapy.Materials and MethodsThis was a retrospective analysis of patients with mild-to-moderate symptomatic knee OA treated with GAE using imipenem-cilastatin sodium. The clinical outcome was scored at baseline and 6 months after treatment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). MR images were scored using the MR imaging osteoarthritis knee score. Linear regression was used to evaluate associations of before-treatment MR imaging scores with WOMAC_pain and WOMAC_total reduction after 6 months.ResultsFifty-four patients (22.2% male; median age, 69.4 years; median WOMAC_pain at baseline, 12) were evaluated. Of all OA features scored, a higher cartilage full-thickness defect score showed the strongest association with less reduction of both WOMAC_pain (B,?0.63 [95% confidence interval (CI), ?0.91 to ?0.34]; P < .001) and WOMAC_total scores (B, ?1.77 [95% CI, ?2.87 to ?0.67]; P < .001) following treatment. The presence of grade 2–3 effusion synovitis (B, ?2.99 [95% CI, ?5.39 to ?0.60]) bone marrow lesions (B, ?0.52 [95% CI, ?0.86 to ?0.19]), osteophytes (B, ?0.21 [95% CI, ?0.36 to ?0.06]), and cartilage defect surface area score (B, ?0.25 [95% CI ?0.42 to ?0.08]) all showed a significant association with less WOMAC_pain reduction (all P < .05).ConclusionsIn patients with mild-to-moderate symptomatic knee OA treated with GAE, the presence and severity of full-thickness cartilage defects, effusion synovitis, bone marrow lesions, osteophytes, and cartilage surface area scores at baseline are associated with less favorable clinical outcomes at 6 months.     

Value Improvement by Assessing IR Care via Time-Driven Activity-Based Costing

PurposeTo evaluate time-driven activity-based costing (TDABC) in interventional radiology for image-guided vascular malformation treatment as an example.Materials and MethodsRetrospective analysis was performed on consecutive vascular malformation treatment cycles [67 venous malformations (VMs) and 11 arteriovenous malformations (AVMs)] in a university hospital in 2018. All activities were integrated with a process map, and spent resources were assigned accordingly. TDABC uses 2 parameters: (i) practical capacity cost rate, calculated as 80% of theoretical capacity, and (ii) time consumption of each resource determined by interviews (23 items). Thereby, the total costs were calculated. Treatment cycles were modified according to identified resource waste and TDABC-guided negotiations with health insurance.ResultsTotal personnel time required was higher for AVM (1,191 min) than for VM (637 min) treatment. The interventional procedure comprised the major part (46%) of personnel time required in AVM, whereas it comprised 19% in VM treatment. Materials represented the major cost type in AVM (75%) and VM (45%) treatments. TDABC-based treatment process modification led to a decrease in personnel time need of 16% and 30% and a cost reduction of 5.5% and 15.7% for AVM and VM treatments, respectively. TDABC-guided cost reduction and TDABC-informed negotiations improved profit from ?56% to +40% and from +41% to +69% for AVM and VM treatments, respectively.ConclusionsTDABC facilitated the precise costing of interventional radiologic treatment cycles and optimized internal processes, cost reduction, and revenues. Hence, TDABC is a promising tool to determine the denominator of interventional radiology's value.     

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.     

Computed Tomography Fluoroscopy–Guided Percutaneous Transhepatic Bleomycin/Ethiodized Oil Sclerotherapy for Symptomatic Giant Hepatic Hemangioma

PurposeTo determine the safety and efficacy of computed tomography (CT) fluoroscopy–guided percutaneous transhepatic sclerotherapy with a bleomycin/ethiodized oil emulsion for symptomatic giant hepatic hemangiomas.Materials and MethodsThe procedure was performed on 22 patients with symptomatic giant hepatic hemangiomas in an outpatient setting between 2018 and 2020. All patients were followed clinically and underwent contrast-enhanced magnetic resonance imaging after 1 month and again at a mean time of 15 months ± 2. Adverse events were classified according to the Common Terminology Criteria for Adverse Events (CTCAE, v5.0), in which a severe adverse event was defined as an adverse event with a grade of ≥3. The desired radiologic response (volume and index size) and improvement of pain intensity (visual analog scale [VAS]) and other symptoms were recorded as outcomes.ResultsOverall, patients showed a 36.4% ± 8.6 reduction in volume and a 14% ± 1.6 reduction in index size after 1 month, with P values of .002 and .001, respectively. The final follow-up volume and index size were 194.7 cm³ ± 25.8 and 77 mm ± 36, respectively. Moreover, a 53.0% ± 7 reduction in volume and 22% ± 3.7 reduction in index size during the final imaging were reported, with the P values of .001 and .001, respectively. Significant reductions in the mean pain intensity (90% of patients with lower VAS scores after intervention) and symptoms were reported. Four patients were classified as clinically unsuccessful, and were recommended further procedures for residual pain.ConclusionsCT fluoroscopy–guided transhepatic sclerotherapy is an effective, safe, and minimally invasive method to manage giant hepatic hemangiomas in an outpatient setting.     

Responsiveness of the Patient-Reported Outcome Measure for Vascular Malformation Questionnaire in Patients with Low-Flow Vascular Malformations

PurposeTo assess the responsiveness, defined as the ability to detect change in a patient’s health or function, of the Patient-Reported Outcome Measure for Vascular Malformation (PROVAM) questionnaire in a cohort of patients with low-flow vascular malformations (VMs).Materials and MethodsPROVAM was previously developed to assess symptoms, functional limitations, and social/emotional effects experienced by patients with VMs. This is a prospective cohort study of 56 patients with venous and lymphatic VMs who completed at least 2 PROVAM questionnaires, of whom 43 had undergone treatment with sclerotherapy in the interim between questionnaires. External responsiveness was assessed using a receiver operating characteristic (ROC) curve to ascertain whether a change in the total PROVAM score predicts whether patients reported symptom improvement and by correlating the change in the total PROVAM score and change in symptoms reported during clinic visit. Internal responsiveness was evaluated using Wilcoxon signed rank test, Cohen d effect size (ESp), and standard response mean difference (SRM).ResultsThe total PROVAM score demonstrated excellent discrimination for symptom improvement with an area under the ROC curve of 0.856. There was a statistically significant, moderate positive correlation between the change in the total PROVAM score and the change in patient symptoms as determined from clinical visits (Spearman correlation coefficient [r_s] = 0.67, P < .001). The total PROVAM score and all subdomain scores improved significantly after treatment (all P < .05). ESp and SRM were 0.80 and 0.83, respectively.ConclusionsPROVAM is responsive to improvement after treatment and may be useful to assess health-related quality of life in patients treated for VMs.     

Transcatheter Arterial Embolization for Benign Chronic Inflammatory Joint Pain: A Systematic Review and Meta-Analysis

PurposeTo evaluate the efficacy and safety of transcatheter arterial embolization (TAE) for the treatment of chronic inflammatory joint pain via systematic review and meta-analysis.Materials and MethodsMEDLINE and EMBASE databases were searched for studies reporting outcomes in patients with chronic inflammatory joint pain treated with TAE. Meta-analyses of pain score changes, changes in proportions of patients on analgesic medications, range of motion changes, technical success rates, and adverse events rates were performed. Subgroup analyses were conducted with respect to pain site (knee versus shoulder).ResultsFourteen observational studies, which included 346 patients, were reviewed. The pooled technical success rate was 95.8%, and no major adverse events were observed. The pooled mean difference in pain score at 1 week was 3.1. At 1, 3, and 6 months, the difference in score was 4.0, 4.2, and 5.1, respectively. At 1 year, the difference was 5.5. Subgroup analysis demonstrated that shoulder embolization was associated with greater reduction of pain than knee embolization at 3 and 6 months (P < .001 and P = .018, respectively), whereas there was no significant difference between the sites at 1 month (P = .734). The pooled proportions of patients on analgesic medication at baseline and at 1, 3, 6, and 12 months were 81.1%, 36.3%, 42.3%, 28.2%, and 22.4%, respectively. The pooled estimated increase in the range of motion among patients who underwent shoulder embolization was 55.6° for anterior elevation and 64.7° for abduction.ConclusionsTAE is an effective and safe therapeutic option for patients with chronic inflammatory joint pain.     

Genicular Artery Embolization for the Treatment of Knee Pain Secondary to Osteoarthritis

PurposeTo evaluate the efficacy and safety of embolization of hyperemic synovial tissue for the treatment of knee pain secondary to osteoarthritis (OA).Materials and MethodsTwenty patients with radiographic knee OA and moderate-to-severe pain refractory to conservative therapy were enrolled in a prospective, 2-site pilot study. Genicular artery embolization (GAE) was performed with 75- or 100-μm spherical particles. Patients were assessed with magnetic resonance imaging at baseline and at 1 month and with the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and at 1, 3, and 6 months. Adverse events were recorded at all timepoints.ResultsEmbolization of at least 1 genicular artery was achieved in 20/20 (100%) patients. Mean VAS improved from 76 mm ± 14 at baseline to 29 mm ± 27 at 6-month follow-up (P < .01). Mean WOMAC score improved from 61 ± 12 at baseline to 29 ± 27 at 6-month follow-up (P < .01). Self-limiting skin discoloration occurred in 13/20 (65%) patients. Two of 20 (10%) patients developed plantar sensory paresthesia that resolved within 14 days.ConclusionsGAE to treat knee pain secondary to OA can be performed safely and demonstrates potential efficacy. Further randomized comparative studies are needed to determine true treatment effect versus placebo effect.     

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.     

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.     

Outcomes of Fluoroscopy-Guided Percutaneous High Ligation of the Great Saphenous Vein Combined With Foam Sclerotherapy for Symptomatic Great Saphenous Veins

PurposeTo evaluate the effectiveness and safety of fluoroscopy-guided percutaneous high ligation (FPHL) combined with fluoroscopy-guided foam sclerotherapy (FGFS) to treat varicose veins of the great saphenous veins (GSVs).Materials and MethodsThis was a retrospective study of 113 patients (mean age, 62.1 ± 10.8 years; 60 men) with varicose veins of the GSVs (133 limbs) that were treated with FPHL combined with FGFS between April 1 and October 31, 2019. Demographic and clinical data were collected from these patients before the FPHL procedure, after which FGFS was performed. The preterminal GSV was ligated percutaneously by a percutaneously-positioned polypropylene ligature under fluoroscopic guidance. The outcome of ligation was confirmed by venography. Then, foam sclerotherapy was performed under fluoroscopy. At 1-year follow-up, GSV occlusion was evaluated by ultrasound. The venous clinical severity scores (VCSSs) were compared between the preoperative and 1-year follow-up periods.ResultsThe technical success rate was 100% (133 limbs). Complete 12-month follow-up was available for 112 limbs (84.2%) and 103 of these limbs (92.0%) remained occluded during this period. The VCSS improved from 4.71 ± 2.15 to 0.74 ± 0.60 (V = 6328, P < .001). During follow-up, there were 16 limbs with thrombophlebitis and 38 limbs with saphenous junction pain; these events were alleviated within 2 weeks of the procedure. There was no deep venous thrombosis or other severe adverse events.ConclusionsFPHL combined with FGFS to treat varicose veins in the GSVs achieved an occlusion rate of 92% and improved the clinical symptoms within 1 year; this minimally-invasive procedure was safe and effective.     

Percutaneous Cryoablation of Symptomatic Intramuscular Venous Malformation

PurposeTo evaluate the efficacy and safety of cryoablation for venous malformations.Materials and MethodsA total of 12 patients with symptomatic intramuscular venous malformations who underwent percutaneous cryoablation between February 2015 and December 2018 were retrospectively studied. The mean age was 42 y (range, 19–58 y). Pain was reported by 11 patients (92%) and swelling by 1 (8%). Pain was assessed with a visual analog scale (VAS) before and after cryoablation. Lesion size was followed with magnetic resonance (MR) imaging at baseline and at 3-mo follow-up. Median initial VAS score was 7 (range, 0–8), and median initial lesion size was 32.5 mm (range, 11–150 mm).ResultsThe median VAS score at 3 mo was 0 (range, 0–4), and the median lesion size at 3 mo was 0 mm (range, 0–142 mm). Eleven of 12 patients reported an improvement in their pain. MR imaging control showed a treatment scar with no residual lesion in 5 patients and decreased lesion size in 4. No major complications were reported. One minor hematoma and 1 small myositis were noted as defined by Society of Interventional Radiology criteria.ConclusionsPercutaneous cryoablation is effective and safe for treatment of symptomatic intramuscular venous malformations, with improvement of symptoms.     

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.     

Safety and Effectiveness of Ethylene Vinyl Alcohol Copolymer Embolization of Peripheral High-Flow Arteriovenous Malformations: Results of a Prospective Study

PurposeTo prospectively evaluate the efficacy and safety of a new ethylene vinyl alcohol (EVOH) copolymer–based embolic agent in the treatment of symptomatic peripheral arteriovenous malformations (AVMs).Materials and MethodsThis prospective single-center study evaluated EVOH embolization with 3 different formulations of EVOH (Squid Peri 12 cP, 18 cP, and 34 cP; BALT Germany GmbH, Düsseldorf, Germany) in patients with symptomatic AVMs. Between April 2018 and October 2019, 36 embolization procedures in 21 patients (3 males and 18 females; mean age, 34.7 years) were performed (inclusion criteria: symptomatic peripheral AVM, ≥14 years of age, and elective embolization). Symptoms, technical aspects (transarterial, transvenous, or percutaneous approach; plug or balloon occlusion), clinical and technical success (defined as the improvement of symptoms and complete angiographic eradication of the AVM nidus), adverse events, and short-term outcomes were assessed.ResultsThe mean volume of the embolic agent used per session was 3.4 mL of EVOH 34 cP (standard deviation [SD], ± 5.4), 6.2 mL ± 8.1 of EVOH 18 cP, and 4.6 mL ± 10.1 of EVOH 12 cP. Angiographic success was achieved in 18 patients (85.7%). The mean follow-up was 190 days (range, 90–538 days; median, 182 days). In the follow-up assessment, findings of magnetic resonance imaging showed that 19 patients (90.5%) had a persistent state of devascularization compared with postinterventional angiography. Amelioration or complete elimination of pain was achieved in 90.0% of the patients. One patient experienced a major adverse event; minor adverse events developed in 2 patients.ConclusionsIn this study, EVOH appeared to be a safe and effective embolic agent in peripheral AVMs and had a low rate of adverse events in a limited number of patients.     

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.