Uterine Artery Embolization for Pedunculated Subserosal Fibroids: A Systematic Review and Meta-Analysis

PurposeTo provide a comprehensive overview of the literature assessing the safety and efficacy of uterine artery embolization (UAE) for patients with pedunculated subserosal fibroids.Materials and MethodsMEDLINE and Embase databases were searched without language or publication type restrictions for observational studies to estimate safety (adverse events) and efficacy (devascularization, fibroid volume reduction, and uterine volume reduction) outcomes. Case reports were included to qualitatively report adverse events. Meta-analysis was performed for single proportions and mean changes with random-effects modeling.ResultsOf 98 eligible articles, 11 studies were included in the final analysis. Of the adverse events detailed in these cases, 5 events were mild, 2 were moderate (torsion of pedunculated fibroid requiring laparoscopic myomectomy and persistent bleeding after embolization requiring hysterectomy), and 1 was severe (fibroid necrosis causing bowel obstruction requiring bowel resection and hysterectomy). There were no deaths reported in the literature. The pooled risk of adverse events was 1.7% (95% confidence interval [CI], 0.29%–9.2%; 4 of 181; I² = 0%). The pooled devascularization rate was 75.9% (95% CI, 62.4%–85.6%; 140 of 189; I² = 75%) at 3.91 months of follow-up. The percent volume reduction of the dominant pedunculated fibroid was 38.6% (95% CI, 33.0%–44.2%; I² = 0%) at 4.3 months of follow-up. The percent uterine volume reduction was 36.7% (95% CI, 30.3%–43.0%; I² = 47%) at 3.5 months of follow-up.ConclusionsUAE for pedunculated subserosal fibroids has a low risk of adverse events and effectively reduces fibroid and uterine size.     

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.     

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.     

Biodegradable Polydioxanone Microspheres for Transcatheter Arterial Embolization: Proof of Principle

PurposeTo evaluate feasibility, embolization success, biodegradability, reperfusion, and biocompatibility of biodegradable microspheres (MS) made from polydioxanone (PDO) for transcatheter arterial embolization.Materials and MethodsUnilateral selective renal embolization of a segmental artery was performed in 16 New Zealand White rabbits with PDO-MS (100–150 μm and 90–315 μm). Animals were randomly assigned to different observation periods and underwent control digital subtraction angiography (DSA) and MR imaging immediately (n = 3), 1 week (n = 2), 4 weeks (n = 2), 8 weeks (n = 2), 12 weeks (n = 5), and 16 weeks (n = 2) after embolization. Kidneys were harvested for macroscopic and histologic analysis of embolization success, biodegradability, and biocompatibility.ResultsEmbolization was technically successful in 15 of 16 animals. One animal died of anesthesia-related circulatory failure. The 100–150 μm MS were injected easily through 3-F catheters; the 90–315 μm MS tended to clog with intermittent catheter obstruction. DSA and MR imaging showed successful target embolization in 13 of 15 animals. In 2 animals, the entire kidney was affected owing to catheter clogging, including a reflux of MS while flushing. Control DSA and MR imaging showed increasing vascular reperfusion with time. Macroscopic and histologic analysis revealed necrosis/infarction in areas in which embolization was achieved. MS were extensively degraded after 16 weeks, and overall inflammatory reaction was mild.ConclusionsBiodegradable PDO-MS induced effective embolization of target vessels while demonstrating good biocompatibility. MS increasingly dissolved at 16 weeks, partial reperfusion started at week 1, and complete reperfusion started at week 8, thus offering possible advantages as a temporary embolic agent.     

Pregnancy Rate and Outcomes following Uterine Artery Embolization for Uterine Arteriovenous Malformations: A Systematic Review and Meta-Analysis

PurposeTo systematically review published studies on the pregnancy rate and outcomes after uterine artery embolization (UAE) for uterine arteriovenous malformations (UAVMs).Materials and MethodsInternational medical databases were searched for all English-language studies published between 2000 and 2022 on patients with UAVMs who had undergone embolization and had a subsequent pregnancy. Data on the pregnancy rate, pregnancy complications, and physiologic status of newborns were extracted from the articles. Ten case series were included in the meta-analysis, and 18 case reports on pregnancy following UAE were reviewed.ResultsIn the case series, 44 pregnancies were reported in 189 patients. The pooled estimate of pregnancy rate was 23.3% (95% confidence interval [CI], 17.3%–29.3%). The pregnancy rate was higher in studies of women with a mean age of ≤30 years (50.6% vs 22.2%; P < .05). The pooled estimate of live birth rate was 88.6% (95% CI, 78.6%–98.7%).ConclusionsAll published series report preservation of fertility and successful pregnancies after embolization of UAVMs. The live birth rate in these series does not differ substantially from that of the general population.     

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.     

Neoadjuvant Yttrium-90 Transarterial Radioembolization with Resin Microspheres Prescribed Using the Medical Internal Radiation Dose Model for Intrahepatic Cholangiocarcinoma

PurposeTo evaluate outcomes of patients with intrahepatic cholangiocarcinoma (iCCA) undergoing neoadjuvant yttrium-90 (⁹⁰Y) transarterial radioembolization (TARE) with resin microspheres prescribed using the Medical Internal Radiation Dose (MIRD) model.Materials and MethodsThis retrospective institutional review board–approved study included 37 patients with iCCA treated with ⁹⁰Y-TARE from October 2015 to September 2020. The primary outcome was overall survival (OS) from ⁹⁰Y-TARE. The secondary outcomes were progression-free survival (PFS), Response Evaluation Criteria In Solid Tumors 1.1 imaging response, and downstaging to resection. Patients with tumor proximity to the middle hepatic vein (<1 cm) and/or insufficient future liver remnant were treated with neoadjuvant intent (n = 21). Patients were censored at the time of surgery or at the last follow-up for the Kaplan-Meier survival analysis.ResultsFor 31 patients (69 years; interquartile range, 64–74 years; 20 men [65%]) included in the study, the first-line therapy was ⁹⁰Y-TARE for 23 (74%) patients. Imaging assessment at 6 months showed a disease control rate of 86%. The median PFS was 5.4 months (95% confidence interval [CI], 3–not reached). The PFS was higher after first-line ⁹⁰Y-TARE (7.4 months [95% CI, 5.3–not reached]) than that after subsequent ⁹⁰Y-TARE (2.7 months [95% CI, 2–not reached]) (P = .007). The median OS was 22 months (95% CI, 7.3–not reached). The 1- and 2-year OS rates were 60% (95% CI, 41%–86%) and 40% (95% CI, 19.5%–81%). In patients treated with neoadjuvant intent, 11 of 21 patients (52%) underwent resections. The resection margins were R0 and R1 in 8 (73%) and 3 (27%) of 11 patients, respectively. On histological review in 10 patients, necrosis of ≥90% tumor was achieved in 7 of 10 patients (70%).ConclusionsFirst-line ⁹⁰Y-TARE prescribed using the MIRD model as neoadjuvant therapy for iCCA results in good survival outcome and R0 resection for unresectable patients.     

Safety and Efficacy of Baseline Antiplatelet Treatment in Patients Undergoing Mechanical Thrombectomy for Ischemic Stroke: Antiplatelets Before Mechanical Thrombectomy

PurposeTo investigate the safety and efficacy of baseline antiplatelet treatment in patients with acute ischemic stroke (AIS) undergoing mechanical thrombectomy (MT).Materials and MethodsBaseline use of antiplatelet medication before MT for (AIS) may provide benefit on reperfusion and clinical outcome but could also carry an increased risk of intracranial hemorrhage (ICH). All consecutive patients with AIS and treated with MT with and without intravenous thrombolysis (IVT) between January 2012 and December 2019 in all centers performing MT nationwide were reviewed. Data were prospectively collected in national registries (eg, SITS-TBY and RES-Q). Primary outcome was functional independence (modified Rankin Scale 0–2) at 3 months; secondary outcome was ICH.ResultsOf the 4,351 patients who underwent MT, 1,750 (40%) and 666 (15%) were excluded owing to missing data from the functional independence and ICH outcome cohorts, respectively. In the functional independence cohort (n = 2,601), 771 (30%) patients received antiplatelets before MT. Favorable outcome did not differ in any antiplatelet, aspirin, and clopidogrel groups when compared with that in the no-antiplatelet group: odds ratio (OR), 1.00 (95% CI, 0.84–1.20); OR, 1.05 (95% CI, 0.86–1.27); and OR, 0.88 (95% CI, 0.55–1.41), respectively. In the ICH cohort (n = 3,685), 1095 (30%) patients received antiplatelets before MT. The rates of ICH did not increase in any treatment options (any antiplatelet, aspirin, clopidogrel, and dual antiplatelet groups) when compared with those in the no-antiplatelet group: OR, 1.03 (95% CI, 0.87–1.21); OR, 0.99 (95% CI, 0.83–1.18); OR, 1.10 (95% CI, 0.82–1.47); and OR, 1.43 (95% CI, 0.87–2.33), respectively.ConclusionsAntiplatelet monotherapy before MT did not improve functional independence or increase the risk of ICH.     

A Pilot First-in-Human Study of Embrace,a Polyethylene Glycol-Based Liquid Embolic Agent,in the Embolization of Malignant and Benign Hypervascular Tumors

PurposeTo investigate the safety and efficacy of an aqueous polyethylene glycol-based liquid embolic agent, Embrace Hydrogel Embolic System (HES), in the treatment of benign and malignant hypervascular tumors.Materials and MethodsA prospective, single-arm, multicenter study included 8 patients, 5 males and 3 females, with a median age of 58.5 years (30–85 years), who underwent embolization in 8 tumors between October 2019 and May 2020. Technical success was defined as successful delivery of HES to the index vessel, with disappearance of >90% of the targeted vascular enhancement or, for portal vein embolization, occlusion of the portal branches to the liver segments for future resection. The volume of HES administered, ease of use (5 point Likert scale), administration time, and adverse events (AEs) were recorded. Evaluation was performed at 7, 30, and 90 days via clinical assessment and blood testing, and follow-up imaging was performed at 30 days.ResultsEight patients were enrolled, and 10 embolizations were performed in 8 lesions. Tumors included hepatocellular carcinoma (n = 4), renal angiomyolipoma (n = 3), and intrahepatic cholangiocarcinoma (n = 1). Technical success was 100%, and the average ease of use was 3.3 ± 1.0 SD. The HES delivery time was 1–28 minutes (median, 16.5 minutes), and the HES volume injected was 0.4–4.0 mL (median, 1.3 mL). All patients reached 30-day follow-up with imaging, and 6 patients reached 90-day follow-up. There were 3 serious AEs in 2 patients that were unrelated to the embolic agent.ConclusionHES resulted in a 100% embolization technical success rate. The product ease of use was acceptable, and no target vessel recanalization was noted on follow-up imaging at 30 days.     

Middle Meningeal Artery Embolization with Liquid Embolic Agents for Chronic Subdural Hematoma: A Systematic Review and Meta-analysis

PurposeTo assess the efficacy and safety of middle meningeal artery (MMA) embolization with liquid embolic agents and the outcomes of patients following this procedure.Materials and MethodsA review of the literature was conducted to identify studies investigating the efficacy and safety of MMA embolization with liquid embolic agents in patients with chronic subdural hematoma (cSDH) in PubMed, Scopus, Embase, and Web of Science. The keywords “liquid embolic agent,” “middle meningeal artery,” “cSDH,” and “embolization” as well as their synonyms were used to build up the search strategy. The R statistical software and random-effects model were used for analysis. Heterogeneity was reported as I², and publication bias was calculated using the Egger test.ResultsOf 628 articles retrieved, 14 studies were eligible to be included in this study. Data of 276 patients were analyzed. n-Butyl cyanoacrylate and ethylene vinyl alcohol copolymer were the most commonly used embolic agents. This study revealed a pooled mortality rate of 0% (95% confidence interval [CI], 0.00%–100%), recurrence and failure rate of 3% (95% CI, 1%–10%), reoperation/reintervention rate of 4% (95% CI, 2%–12%), rate of size decrease of 94% (95% CI, 79%–98%), technical success rate of 100% (95% CI, 76%–100%), and adverse event rate of 1% (95% CI, 0.00%–4%).ConclusionsWith low mortality, recurrence, reoperation, and adverse event rates and a remarkable decrease in the size of hematomas, MMA embolization with liquid embolic agents may be considered a safe and effective treatment option in patients in whom surgical intervention has previously failed and as an alternative to conventional treatments.     

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.     

Investigating the Underutilization of Uterine Fibroid Embolization by Surveying Practice Preferences of Obstetricians/Gynecologists

This study aimed to survey the practice preferences of obstetricians/gynecologists (OB/GYNs) that may be contributing to the underutilization of uterine fibroid embolization (UFE) in the treatment of symptomatic uterine fibroids (SUFs). A 22-question survey was created using the Qualtrics XM software and distributed to an obstetrics/gynecology–specific social media group of resident or attending OB/GYNs practicing in the United States. One hundred twelve responses met the inclusion criteria. For patients with SUFs, UFE was offered as a first-choice option <2% of the time. For patients with SUFs seeking to maintain fertility, UFE was recommended only 1% of the time after medical therapy (54%) and myomectomy (42%). Respondents reported lower rates of confidence (selecting “strongly agree” or “agree”) regarding risks and benefits of UFE (77%) in comparison with those of myomectomy (99%) or hysterectomy (100%). Because UFE was seldom recommended by respondents, further, more robust polling of OB/GYNs is warranted.     

Prospective Study of Radial Artery Occlusion Following Transradial Arterial Access during IR Procedures

PurposeTo prospectively determine the rate of radial artery occlusion (RAO) in patients undergoing transradial access for intra-arterial interventions.Materials and MethodsSeventy-seven patients undergoing transradial access from August 2019 to March 2021 for 120 intra-arterial procedures (yttrium-90 mapping [n = 39] and radioembolization [n = 38], uterine artery embolization [n = 19], transarterial chemoembolization [n = 10], active bleed embolization [n = 8], angiomyolipoma embolization [n = 4], and other [n = 2]) were enrolled. The average patient age was 59 years ± 13.1 (range, 30–90 years), and 43 (55.8%) of the 77 patients were men. The patients underwent radial artery (RA) palpation, ultrasound evaluation, the Barbeau test, and the reverse Barbeau test prior to and following the intervention. Verapamil, nitroglycerin, and heparin were administered in a total of 114 (95%) of the 120 procedures prior to starting the procedure. The incidence of RAO and radial artery spasm (RAS) was calculated, and univariate logistic regression was performed to analyze the predictors of RAS.ResultsThe preprocedural RA diameter (3.0 mm ± 0.67) was not significantly different from the postprocedural RA diameter (3.0 mm ± 0.65, P = .904). The RAO rate was determined to be 0.8% (1/120), and this artery recanalized within 1 week. Due to the small number of occlusions, statistical analysis of predictors of RAO was not performed. The rate of RAS was 22.7% (27/119). None of the variables tested—including age, sex, RA diameter, initial versus repeat access, operator experience, and artery puncture technique—showed significant prediction for RAS. Patients were seen for follow-up after 111 (92.5%) of the 120 procedures.ConclusionsTransradial access resulted in a <1% rate of RAO.     

4D Flow MR Imaging to Improve Microwave Ablation Prediction Models: A Feasibility Study in an In Vivo Porcine Liver

PurposeTo characterize the effect of hepatic vessel flow using 4-dimensional (4D) flow magnetic resonance (MR) imaging and correlate their effect on microwave ablation volumes in an in vivo non-cirrhotic porcine liver model.Materials and MethodsMicrowave ablation antennas were placed under ultrasound guidance in each liver lobe of swine (n = 3 in each animal) for a total of 9 ablations. Pre- and post-ablation 4D flow MR imaging was acquired to quantify flow changes in the hepatic vasculature. Flow measurements, along with encompassed vessel size and vessel-antenna spacing, were then correlated with final ablation volume from segmented MR images.ResultsThe linear regression model demonstrated that the preablation measurement of encompassed hepatic vein size (β = –0.80 ± 0.25, 95% confidence interval [CI] –1.15 to –0.22; P = .02) was significantly correlated to final ablation zone volume. The addition of hepatic vein flow rate found via 4D flow MRI (β = –0.83 ± 0.65, 95% CI –2.50 to 0.84; P = .26), and distance from antenna to hepatic vein (β = 0.26 ± 0.26, 95% CI –0.40 to 0.92; P = .36) improved the model accuracy but not significantly so (multivariate adjusted R² = 0.70 vs univariate (vessel size) adjusted R² = 0.63, P = .24).ConclusionsHepatic vein size in an encompassed ablation zone was found to be significantly correlated with final ablation zone volume. Although the univariate 4D flow MR imaging-acquired measurements alone were not found to be statistically significant, its addition to hepatic vein size improved the accuracy of the ablation volume regression model. Pre-ablation 4D flow MR imaging of the liver may assist in prospectively optimizing thermal ablation treatment.     

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.     

Diagnostic Performance of CT-Guided Bone Biopsies in Patients with Suspected Osteomyelitis of the Appendicular and Axial Skeleton with a Focus on Clinical and Technical Factors Associated with Positive Microbiology Culture Results

PurposeTo assess diagnostic performance of CT-guided percutaneous needle bone biopsy (CTNBB) in patients with suspected osteomyelitis and analyze whether certain clinical or technical factors were associated with positive microbiology results.Materials and MethodsAll CTNBBs performed in a single center for suspected osteomyelitis of the appendicular and axial skeleton during 2003–2018 were retrospectively reviewed. Specific inclusion criteria were clinical and radiologic suspicion of osteomyelitis. Standard of reference was defined using outcome of surgical histopathology and microbiology culture and clinical and imaging follow-up. Technical and clinical data (needle size, comorbidities, clinical factors, laboratory values, blood cultures) were collected. Logistic regression was performed to assess associations between technical and clinical data and microbiology biopsy outcome.ResultsA total of 142 CTNBBs were included (46.5% female patients; age ± SD 46.10 y ± 22.8), 72 (50.7%) from the appendicular skeleton and 70 (49.3%) from the axial skeleton. CTNBB showed a sensitivity of 42.5% (95% confidence interval [CI], 32.0%–53.6%) in isolating the causative pathogen. A higher rate of positive microbiology results was found in patients with intravenous drug use (odds ratio [OR] = 5.15; 95% CI, 1.2–21.0; P = .022) and elevated white blood cell count ≥ 10 × 10⁹/L (OR = 3.9; 95% CI, 1.62–9.53; P = .002). Fever (≥ 38°C) was another clinical factor associated with positive microbiology results (OR = 3.6; 95% CI, 1.3–9.6; P = .011).ConclusionsCTNBB had a low sensitivity of 42.5% for isolating the causative pathogen. Rate of positive microbiology samples was significantly higher in patients with IV drug use, elevated white blood cell count, and fever.     

MR Imaging Volumetric Response after Yttrium-90 Radioembolization for Colorectal Liver Metastases: Predictability at Baseline and Correlation with Survival

PurposeTo prove the utility of magnetic resonance (MR) imaging response as a surrogate end point of treatment efficacy and survival after yttrium-90 transarterial radioembolization (TARE) for colorectal liver metastases (CRLMs), and to investigate whether outcomes can be predicted at baseline using MR imaging or clinical variables.Materials and MethodsA total of 50 (135) patients with TARE for CRLMs between August 2008 and January 2020 and peri-interventional MR imaging within defined timeframes were included for tumor segmentation. Pretreatment and posttreatment target tumor volumes were measured according to the volumetric Response Evaluation Criteria In Solid Tumors (vRECIST) and the quantitative European Association for the Study of the Liver (qEASL) criteria. Cox regression models were used to analyze the impact of MR morphologic response, vascularity at baseline, and clinical variables on patient survival. Logistic regression analyses were used to evaluate the predictors of MR morphologic response at baseline.ResultsThe median survival was 337 days (95% confidence interval [CI], 243–431). As opposed to the vRECIST, the application of the qEASL criteria 3 months after the treatment allowed for a significant (P < .05) separation of the survival curves for partial response, stable disease, and progressive disease with a median survival of 412 days (95% CI, 57–767) in responders. High tumor burden and technetium-99m lung shunt significantly decreased the probability of survival. MR morphologic response was not predictable at baseline using imaging or clinical data.ConclusionsMR response according to the qEASL criteria outperformed the vRECIST in measuring the biologic impact of TARE and predicting patient survival. Baseline contrast enhancement did not predict MR response to treatment, which may reflect elevated dose requirements in tumors with a high proportion of viable tumor volume.     

Image-Guided Ablation of Recurrent or Unresectable Intrahepatic Cholangiocarcinoma

PurposeTo assess the safety and effectiveness of image-guided ablation of recurrent or unresectable intrahepatic cholangiocarcinoma (ICC).Materials and MethodsIn this retrospective study, 25 patients (14 women; age, 36–84 years) underwent 37 image-guided liver tumor ablation procedures to treat 47 ICCs (May 2004 to January 2022). At initial diagnosis, 20 patients had Stage 1 or 2 disease and 5 had Stage 3 or 4 disease. Before ablation, 19 (76.0%) of the 25 patients had progressed through prior treatments, including resection (n = 11), chemotherapy (n = 11), transarterial embolization (n = 3), or radiotherapy (n = 1); 6 (24.0%) of the 25 patients were treatment naïve. Ablation modality selection was based on patient and tumor characteristics and operator preference. Primary outcomes included local progression–free survival (LPFS) and overall survival (OS) after ablation. Statistical analysis included Kaplan-Meier (KM) survival analyses and Cox proportional hazards models.ResultsThe mean ablated tumor size was 2.0 cm ± 1.2 (range, 0.5–5.0 cm). The 1-, 2-, and 5-year LPFS rates were 84.0% (95% CI, 72.9–96.8), 73.0% (95% CI, 59.0–90.4), and 59.5% (95% CI, 41.6–85.1), respectively. The 1-, 2-, and 5-year secondary LPFS rates were 89.5% (95% CI, 80.2–99.9), 81.9% (95% CI, 69.4–96.6), and 75.6% (95% CI, 60.2–94.9). The 1-, 2-, and 5-year LPFS rates for tumors ≤2 cm in size were all 95.8% (95% CI, 88.2–100.0). The 1-, 2-, and 5-year OS rates were 78.5% (95% CI, 63.5–97.2), 68.4% (95% CI, 51.3–91.1), and 43.5% (95% CI, 23.5–80.5). Larger tumor size was associated with decreased time to local progression (hazard ratio, 1.93; P = .012).ConclusionsPercutaneous ablation provided favorable intermediate to long-term disease control for patients with recurrent or inoperable cholangiocarcinoma.     

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.     

Safety and Efficacy of Arterially Directed Liver Therapies in the Treatment of Hepatic Metastatic Ovarian Cancer: A Retrospective Single-Institution Study

PurposeTo evaluate the safety and efficacy of 2 locoregional therapies (LRTs) including hepatic artery embolization (HAE) and transarterial radioembolization (TARE) in the treatment of patients with metastatic ovarian cancer to the liver.Material and MethodsFrom October 2010 to May 2019, the data of 15 consecutive patients (median age, 54 years ± 9.8; range, 35–78 years) with hepatic metastatic ovarian cancer who were treated with either HAE (n = 6; 40%) or TARE (n = 9; 60%) were reviewed. The most common histopathologic type was epithelial ovarian carcinoma (80%). The most common chemotherapy regimens used prior to embolization included carboplatin, paclitaxel, cisplatin, and bevacizumab. Patients received a mean of 4 lines ± 3 (range, 1–9) of chemotherapy. All patients with serous carcinoma were resistant to platinum at the time of embolization. Indications for embolization were progression of disease to the liver while receiving chemotherapy in 14 (93.3%) patients and palliative pain control in 1 patient.ResultsThe overall response rates at 1, 3, and 6 months were 92.4%, 85.6%, and 70%, respectively. Median overall survival from the time of LRT was 9 (95% confidence interval [CI], 4–14) months. Median local tumor progression was 6.4 months ± 5.03 (95% CI, 3.3–9.5). No grade 3–5 adverse events were detected in either group.ConclusionsHAE and TARE were well tolerated in patients with metastatic ovarian cancer to the liver and possibly ensured prolonged disease control in heavily treated, predominantly in patients resistant to platinum. Larger numbers are needed to verify these data.