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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 973 records · Page 54
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Arms Down Cone Beam CT Hepatic Angiography Performance Assessment: Vascular Imaging Quality and Imaging Artifacts

IntroductionThe practice of positioning patients’ arms above the head during catheter-injected hepatic arterial phase cone beam CT (A-CBCT) imaging has been inherited from standard CT imaging due to image quality concerns, but interrupts workflow and extends procedure time. We sought to assess A-CBCT image quality and artifacts with arms extended above the head versus down by the side.MethodsWe performed an IRB approved retrospective evaluation of reformatted and 3D-volume rendered images from 91 consecutive A-CBCTs (43 arms up, 48 arms down) acquired during hepatic tumor arterial embolization procedures. Two interventional radiologists reviewed all A-CBCT imaging and assigned vessel visualization scores (VVS) from 1 to 5, ranging from non-diagnostic to optimal visualization. Streak artifacts across axial images were rated from 1 to 3 based on resulting image quality (none to significant). Presence of respiratory or cardiac motion during acquisition, body mass index and radiation dose area product (DAP) were also recorded and analyzed. Univariate and multivariate analyses were used to assess the impact of arm position on VVS and imaging artifacts.ResultsVVS were not significantly associated with arm position during A-CBCT imaging. One reader reported more streak artifacts across axial images in the arms down group (p = 0.005). DAP was not statistically different between the groups (23.9 Gy cm{sup 2} [6.1–73.4] arms up, 26.1 Gy cm{sup 2} [4.2–102.6] arms down, p = 0.54).ConclusionA-CBCT angiography performed with the arms above the head is not superior for clinically relevant hepatic vascular visualization compared to imaging performed with the arms by the patient’s side.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Transfemoral Venous Access Facilitates Upper Extremity Dialysis Interventions: Procedural Success and Clinical Outcomes

Purpose: To report technical success and clinical outcomes of transfemoral venous access for upper extremity dialysis interventions. Materials and Methods: A total of 15 patients underwent a transfemoral venous approach for fistulography (n = 4; 27%) or thrombectomy (n = 11; 73%) over a 14-month period. Access characteristics, sheath size, thrombectomy method, angioplasty site, fluoroscopy time, radiation dose, technical and clinical success, complications, and post-intervention primary and secondary patency rates were recorded. Results: Access type included arteriovenous fistulas (n = 10; 67%) and grafts (n = 5; 33%). The most common configuration was brachio-brachial (n = 6; 38%). Mean age of access was 37 months. Mean prior interventions were 4. Right CFV access was used in all patients using 6–8-French (most common: 7-French [n = 10; 67%]) sheaths. Most thrombectomies (n = 11; 73%) required both pharmacologic and mechanical maceration (n = 9; 82%). All accesses required angioplasty to treat underlying stenosis at the outflow vein (n = 12; 80%) or arteriovenous anastomosis (n = 9; 90%). Mean fluoroscopy time was 26.43 min. Air kerma and dose area product were 178.06 ± 225.77 mGy and 57,768.83 ± 87,553.29 μGym{sup 2}, respectively. Procedural and clinical success rates were 93% and 80%, respectively. Technical failure was due to persistent stenosis in one patient. Clinical failure was due to unsuccessful dialysis immediately following intervention in three patients. Mean post-intervention primary patency and secondary patency durations were 2.8 and 4.8 months, respectively. Primary patency rates at 1 and 3 months were 50% and 35%, respectively. Secondary patency rates at 1 and 3 months were 58% and 30%, respectively. Conclusion: A transfemoral venous approach for intervention of upper extremity dialysis accesses may be a valuable adjunct to traditional approaches.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Segment 2/3 Hypertrophy is Greater When Right Portal Vein Embolisation is Extended to Segment 4 in Patients with Colorectal Liver Metastases: A Retrospective Cohort Study

Background: In patients with colorectal cancer liver metastases (CRLM), right portal vein embolisation (RPVE) is used to increase the volume of the future remnant liver (FRL) before major hepatic resection. It is not established whether embolisation of segment 4 in addition RPVE (RPVE + 4) induces greater hypertrophy of the FRL. Limitations of prior studies include heterogenous populations and use of hypertrophy metrics sensitive to baseline variables. Methods: From 2010 to 2015, consecutive patients undergoing RPVE or RPVE + 4 for CRLM, who had not undergone prior major hepatic resection and in whom imaging was available, were included in a retrospective study. Data were extracted from hospital electronic records. Volumetric assessments of segments 2–3 were made on cross-sectional imaging before and after embolisation and corrected for standardised liver volume. Results: Ninety-nine patients underwent PVE, and 60 met the inclusion criteria. Thirty-eight patients underwent RPVE, and 22 underwent RPVE + 4. Forty-five patients had undergone median 6 cycles of prior chemotherapy. Eighteen patients had FRL metastases at PVE, and 16 had undergone subsegmental metastasectomy in the FRL. Assessments of the degree of hypertrophy (DH) of segments 2/3 were made at median 35 (interquartile range 30–49) days after PVE. RPVE + 4 resulted in a significantly greater increase in DH than RPVE (7.7 ± 1.8% vs 11.3 ± 2.6%, p = 0.011). No confounding association between baseline variables and the decision to undertake RPVE or RPVE + 4 was identified. Median survival was 2.4 years and was not influenced by segment 4 embolisation. Conclusion: RPVE + 4 results in greater DH of segments 2/3 than RPVE in people with CLRM.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Outcomes After Transarterial Embolization of Neuroendocrine Tumor Liver Metastases Using Spherical Particles of Different Sizes

Purpose: To evaluate initial response and overall survival of neuroendocrine tumor (NET) liver metastases initially treated with transarterial embolization (TAE) using spherical particles of different sizes. Methods: A single-institution retrospective review was performed of 160 patients with NET liver metastases initially treated with TAE using < 100 µm (n = 77) or only ≥ 100 µm (n = 83) spherical particles. For each patient, we evaluated: initial response by mRECIST, time to progression, overall survival, complications, primary site, tumor grade and degree of differentiation, volume of liver disease, extrahepatic disease, NET-related symptoms, comorbidities, Child–Pugh score, performance status, lobar versus selective embolization, and arteriovenous shunting. Results: Initial response was higher for TAE using particles < 100 versus TAE using only particles ≥ 100 μm (64 vs 42%, p = 0.007). Multivariate logistic regression showed that use of particles < 100 μm and liver < 50% replaced with tumor were independent predictors of a better initial response rate. There was no difference in major or minor complications between the two particle size groups. Median overall survival after TAE was 55 months for well- to moderately differentiated NET and 13 months for poorly differentiated or undifferentiated NET. There was no significant difference in survival between TAE patients treated with < 100 versus only ≥ 100-μm particles. Conclusion: NET patients treated with TAE using particles < 100 μm had better initial response, but the same overall survival, compared to TAE using only particles ≥ 100 μm.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Which G-Tube to Use in Pullers: Assessment of Pull Pressures on Skin Models to Determine Optimal Catheter Choice in Patients with Recurrent Pulled Gastrostomy Tubes

Introduction: Pulled or dislodged gastrostomy catheters represent a common complication associated with percutaneous gastrostomy and are a common cause of recurrent visits in patients with altered mental status. We intended to perform an experiment to compare the pull forces required to dislodge different commonly used gastrostomy catheters. Materials and Methods: We used a digital force gauge device to measure the pull forces required to dislodge three types of 20 French gastrostomy catheters in double-layer skin models. These included the Flow 20 Pull Method (Cook Medical, Bloomington, IN, USA), Entuit Gastrostomy BR Balloon Retention feeding tube (Cook Medical, Bloomington, IN, USA), and Ponsky Non-Balloon Replacement Gastrostomy Tube (CR Bard Inc, Salt Lake City, Utah, USA). The catheters were inserted into the skin model using the same technique as would be utilized in a patient. Results: The mean forces measured to dislodge the per-oral Flow 20 Pull Method, Entuit Thrive Balloon Retention, and button-type retention Ponsky replacement catheters were 35.6, 22.8, and 20.6 Newtons, respectively. The pull method per-oral gastrostomy catheter required significantly more pull force to dislodge than both the Ponsky button-type retention catheter and the Entuit balloon retention catheters. There was no significant difference in the pull force required to dislodge the Ponsky replacement catheter and the Entuit balloon retention catheter. Conclusions: Per-oral image-guided gastrostomy with pull-method button-type retention catheters may be the ideal choice in patients at high risk of tube dislodgment.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Long-Term Evaluation of Percutaneous Groin Access for EVAR

Background: Percutaneous endovascular aneurysm repair (PEVAR) has been shown to have high success rates, shorter operating times and length of stay compared to open access. However, there exists a lack of long-term follow-up data on these patients, and questions remain regarding longer-term outcomes. This study aims to assess the long-term complications and evolution of accessed vessels post-PEVAR. Methods: Sixty-one cases of bilateral PEVAR (122 groins) with > 36 months follow-up were analysed. Vessel diameter, calcification, dissection, lymphocele, pseudoaneurysm and thrombus formation were reviewed at 30th day and at the most recent follow-up CT. Notes were reviewed for groin infections, haematomas and nerve injury. Complications were considered ‘major’ if they required intervention or treatment. Results: Mean follow-up time from procedure to most recent scan was 49.9 months. There were no major short- or long-term complications. The early complication rate was 9.8%, with six pseudoaneurysms, four dissections, one thrombus, one nerve injury and no lymphoceles, haematomas or groin infections. The long-term complication rate was 0.8%, with only one pseudoaneurysm. The remainder of early complications resolved naturally without intervention. Accessed vessel showed significantly (P ≤ 0.05) increased diameter and calcification between 30th day and last follow-up scan. Conclusion: This study provides the largest clinical cohort and the longest mean follow-up time reported in the literature and demonstrates the long-term safety of PEVAR. PEVAR has a very low long-term complication rate, without any major complications in our cohort. The accessed common femoral arteries do not show stenosis or thrombosis. Minor short-term complications appear to gradually resolve without intervention. Larger multi-centre studies are recommended.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

The Relationship Between Gelatin Sponge Preparation Methods and the Incidence of Intrauterine Synechia Following Uterine Artery Embolization for Postpartum Hemorrhage

Purpose: To evaluate the relationship between gelatin sponge preparation methods and the incidence of intrauterine synechia following uterine artery embolization (UAE) for postpartum hemorrhage (PPH). Materials and Methods: In a retrospective monocentric study, we used data from 20 consecutive UAE procedures (19 patients) for PPH, performed in 2007–2016, in which gelatin sponge had been used. The gelatin sponge was processed either into a slurry by pumping it back and forth about 10 times through two syringes connected to a three-way stopcock or into pledgets using a scalpel and small scissors to obtain pieces approximately 2 × 2 × 2 mm in size. Patient information was obtained from medical records, and the data were compared between patients treated with the slurry (n = 7) or pledgets (n = 13) forms. Due to the lack of follow-up data and hysterectomy after UAE, the sample size was 6 and 12 because 1 patient with 2 procedures was excluded. Results: The rate of intrauterine synechia was significantly higher in the slurry group (5/6, 83.3%) than that in the pledgets group (0/12, 0%; P < 0.001). In contrast, there were no significant differences in population characteristics, such as the incidence of placenta accreta, non-placental diseases, and severity of shock (DIC score, shock index, or blood loss) between the groups. Conclusions: Although non-randomization and small sample size were the two main limitations, our observations suggest that UAE using gelatin sponge slurry may be associated with a high incidence of intrauterine synechia compared to UAE using pledgets.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Establishing a Platform for Interest and Education in Interventional Radiology Amongst Radiology Trainees

Purpose: Over recent times, procedural Radiologists have begun to establish themselves as the distinct subspecialty of Interventional Radiology (IR). The Interventional Radiology Society of Australasia (IRSA) was established in 1982 to share collaborative ideas, encourage research, and promote education. IRSA developed a weekend registrar workshop attended by Radiology Registrars from Australia and New Zealand. In the 2018 event, we surveyed the Registrars to identify their interest in IR training before and after the workshop. Materials and Methods: The event was held over a weekend and consisted of both lectures and hands-on workshops. A survey was handed to all 67 registrants of the workshop and there was a 55% response rate including 78% of females in attendance. Results: Before the workshop, trainees rated their interest in IR training at a mean of 3.7 out of 5. After the workshop, trainees rated their interest in IR training as an average of 4.4 out of 5 (p < 0.001). The difference in interest between males and females before the workshop (4.0 vs. 3.1) was significant (p = 0.003), however after the workshop (4.5 vs. 4.1) was not significant (p = 0.07). The change in interest from attending the workshop was significant between genders, p = 0.03 (male interest increased mean 0.5, female increased mean 1.0). Conclusion: We show that a program of lectures and workshops designed to generate interest in IR leads to a significant increase in training interest, particularly amongst females. Other subspecialty groups should consider this type of intervention and promote ongoing education and inspiration. Level of Evidence: Cross-sectional study, Level IV.

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DOE OSTI2019

Uterine Artery Embolization in Women with Symptomatic Cervical Leiomyomata: Efficacy and Safety

Purpose: To perform an evaluation on safety and efficacy of uterine artery embolization (UAE) in the patients with symptomatic cervical leiomyomata. Methods: Patients with symptomatic cervical leiomyomata who underwent UAE in one specialized hospital were retrospectively analyzed, both clinically and with MR imaging. The 3-month outcomes were assessed with MR imaging and a validated questionnaire. Long-term follow-up was assessed by direct contact or file review. To determine the efficacy of UAE for cervical leiomyomata, the primary objective was to assess the clinical outcome with the UFS-QOL questionnaire, containing the health-related quality of life (HRQOL) and symptom severity score (SSS). To assess safety, the secondary objective included leiomyomata volume reduction, the infarction/complication rate and secondary interventions were needed. Results: Between 2006 and 2017, eight of 1180 patients underwent UAE and were eligible for inclusion. All embolizations were technically successful (n = 8). At 3 months, all patients showed cervical leiomyomata volume reduction with a median reduction of 41.5% (38.8 cm{sup 3}) compared to baseline (p = 0.012). No complications occurred. At a median follow-up of 3 months (range 1–7, n = 7), the HRQOL and SSS improved with a median difference of 13 points (range − 5 to 60, p = 0.063) and − 13 points (range − 79 to 3, p = 0.046), respectively. Long-term follow-up showed two secondary interventions (median of 43.5 months). Six patients reported no symptom recurrence. Conclusion: UAE in women with symptomatic cervical leiomyomata is effective and safe with significant improvement in symptoms and quality of life. UAE is a valuable option for women seeking a non-surgical solution.

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DOE OSTI2019

Real-Time US-{sup 18}FDG-PET/CT Image Fusion for Guidance of Thermal Ablation of {sup 18}FDG-PET-Positive Liver Metastases: The Added Value of Contrast Enhancement

Purpose: To assess the feasibility of US-{sup 18}FDG-PET/CT fusion-guided microwave ablation of liver metastases either poorly visible or totally undetectable with US, CEUS and CT, but visualized by PET imaging. Materials and Methods: Twenty-three patients with 58 liver metastases underwent microwave ablation guided by image fusion system that combines US with {sup 18}FDG-PET/CT images. In 28/58 tumors, {sup 18}FDG-PET/CT with contrast medium (PET/CECT) was used. The registration technical feasibility, registration time, rates of correct targeting, technical success at 24 h, final result at 1 year and complications were analyzed and compared between the PET/CT and PET/CECT groups. Results: Registration was successfully performed in all cases with a mean time of 7.8 + 1.7 min (mean + standard deviation), (4.6 + 1.5 min for PET/CECT group versus 10.9 + 1.8 min for PET/CT group, P < 0.01). In total, 46/58 (79.3%) tumors were correctly targeted, while 3/28 (10.7%) and 9/30 (30%) were incorrectly targeted in PET/CT and PET/CECT group, respectively (P < 0.05). Complete ablation was obtained at 24 h in 70.0% of cases (n = 40 tumors), 23/28 (82.1%) in the PET/CECT group and 17/30 (56.7%) in the PET/CT group (P < 0.037). Fourteen tumors underwent local retreatment (11 ablations, 2 with resection and 1 with stereotactic body radiation therapy), while 4 tumors could not be retreated because of distant disease progression and underwent systemic therapy. Finally, 54/58 (93.1%) tumors were completely treated at 1 year. One major complication occurred, a gastrointestinal hemorrhage which required surgical repair. Conclusions: Percutaneous ablation of {sup 18}FDG-PET-positive liver metastases using fusion imaging of real-time US and pre-acquired {sup 18}FDG-PET/CT images is feasible, safe and effective. Contrast-enhanced PET/CT improves overall ablation accuracy and shortens procedural duration time.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Ablation Volume Measurement After Percutaneous Cryoablation Using a Two-cryo-probe Technique for Small Hepatocellular Carcinomas

Purpose: To calculate the ablation volume of percutaneous cryoablation (PCA) with a two-cryo-probe technique for small hepatocellular carcinomas (HCCs) and to assess risk factors for local tumor recurrence (LTR). Materials and Methods: Between January 2013 and June 2017, 96 patients (mean age, 60.7 years; range, 37–83 years) with 106 small HCCs were retrospectively analyzed. The ablation volume, technical success, LTR rates, and complications were evaluated. Ablation volume was measured after the first freezing and immediately after completing PCA twice via computed tomography imaging. Prognostic factors associated with LTR were analyzed. Results: Technical success was achieved in all patients. The mean final ablation volume was 19.1 ± 4.8 cm{sup 3}, which was significantly higher than the first freezing ablation volume (14.7 ± 4.3 cm{sup 3}, p < 0.001). During the median follow-up period of 16.7 months (range, 5–52 months), LTR-free survival rates based on Kaplan–Meier analyses at 6 months, 1 year, and 2 years were 87.7%, 84.0%, and 80.2%, respectively. Only one major complication of post-procedural arterial bleeding occurred. A final ablation volume/tumor volume < 10 was a significant risk factor for LTR (p = 0.044). Conclusions: A ratio of final ablation volume to tumor volume < 10 was a significant prognostic factor for LTR. Therefore, the measurement and prediction of the final ablation volume are important to reduce LTR.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Robotically Assisted CBCT-Guided Needle Insertions: Preliminary Results in a Phantom Model

Aim: To compare robotic-assisted needle insertions performed under CBCT guidance to standard manual needle insertions. Materials and Methods: A homemade robotic prototype was used by two operators to perform robotic and manual needle insertions on a custom-made phantom. Both the operators had no experience with the prototype before starting the trial. The primary endpoint was accuracy (i.e., the minimal distance between the needle tip and the center of the target) between robotic and manual insertions. Secondary endpoints included total procedure time and operators’ radiation exposure. The Wilcoxon test was used. A p value less than 0.05 was considered statistically significant. Results: Thirty-three (17 manual, 16 robotic) needle insertions were performed. Mean accuracy for robotic insertion was 2.3 ± 0.9 mm (median 2.1; range 0.8–4.2) versus 2.3 ± 1 mm (median 2.1; range 0.7–4.4) for manual insertion (p = 0.84). Mean procedure time was 683 ± 57 s (median 670; range 611–849) for the robotic group versus 552 ± 40 s (median 548; range 486–621) for the manual group (p = 0.0002). Mean radiation exposure was 3.25 times less for the robotic insertion on comparison to manual insertion for the operator 1 (0.4 vs 1.3 µGy); and 4.15 times less for the operator 2 (1.9 vs 7.9 µGy). Conclusion: The tested robotic prototype showed accuracy comparable to that achieved with manual punctures coupled to a significant reduction of operators’ radiation exposure. Further, in vivo studies are necessary to confirm the efficiency of the system.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Approach, Technical Success, Complications, and Stent Patency of Sharp Recanalization for the Treatment of Chronic Venous Occlusive Disease: Experience in 123 Patients

Purpose: To report the technical success and complications following sharp recanalization of chronic venous occlusions. Materials and Methods: A total of 123 patients, including 75 (61.0%) men and 48 (39.0%) women, with mean age of 50.5 ± 17.5 years (range 19–90 years), underwent sharp recanalization of chronic venous occlusions. The etiologies of occlusion were chronic deep venous thrombosis (n = 43; 35.0%), prior central venous access (n = 39; 31.7%), indwelling cardiac leads (n = 21; 17.1%), and occluded venous stents (n = 20; 16.3%). The sites of venous occlusion included 59/123 (48.0%) thoracic central veins, 37 (30.1%) non-thoracic central veins, and 27 (22.0%) peripheral veins. Median length of occlusion was 3.2 ± 1.4 cm (range 1.3–10.9 cm). Results: Sharp recanalization was most commonly attempted with transseptal needles in 108/123 (87.8%), with a mean number of 1.2 ± 0.4 crossing devices per patient (range 1–4 devices). Targeting devices included a loop snare (n = 92; 74.8%), partially deployed Wallstent (n = 21; 17.1%), partially deployed Amplatzer vascular plug (n = 8; 6.5%), and an angioplasty balloon (n = 3; 2.4%). Technical success was achieved in 111 (90.2%) patients. There were 3 (2.4%) severe, 1 (0.8%) moderate, and 7 (5.7%) minor adverse events. Severe adverse events included 1 case each of pericardial tamponade, hemothorax, and inferior vena cava filter occlusion. 88 (71.5%) patients had venous stents placed; at the last follow-up examination, 68/86 (79.0%) stents were patent. Conclusion: Sharp recanalization has a high technical success and low rate of adverse events in the recanalization of chronic venous occlusions.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Endovascular Stroke Therapy with a Novel 6-French Aspiration Catheter

Background and Purpose: Direct thrombus aspiration is increasingly used as a first-line therapy in acute ischemic stroke with large vessel occlusion. We assessed the performance and safety of a novel aspiration catheter available: the 6-French AXS Catalyst catheter. Materials and Methods: We conducted a cohort study from a prospective clinical registry of consecutive stroke patients treated by mechanical thrombectomy between March 2016 and July 2016. Baseline clinical and imaging characteristics, recanalization rates, complications, and clinical outcomes were analyzed. Results: Among the 60 patients included, 30 were treated using aspiration alone, 14 were treated using aspiration and then stent retriever as a rescue therapy, and 16 were treated using aspiration combined with a stent retriever straightaway. Successful recanalization (mTICI2b/3) was achieved in 85% patients and functional independence in 48.3%. We observed one intracranial perforation and one vertebral artery dissection. Symptomatic intracranial hemorrhage occurred in 5% and mortality in 21.7%. Conclusion: Endovascular stroke therapy using the AXS Catalyst catheter seems safe and effective, with similar performance than other reperfusion catheters.

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DOE OSTI2019

Focal Stenting of Complex Femoropopliteal Lesions with the Multi-LOC Multiple Stent Delivery System: 12-Month Results of the Multicenter LOCOMOTIVE Study

Introduction: The purpose of this observational study is to report the 12-month clinical outcomes with the novel Multiple Stent Delivery System (MSDS) to treat complex femoropopliteal lesions. Previously, we reported the 6-month clinical outcomes of the all-comers LOCOMOTIVE study, which demonstrated the safety and efficacy of the MSDS with a favorable target lesion revascularization (TLR) rate of 5.3% and a 90.7% patency rate at 6 months in claudicants and critical limb ischemia patients. The 12-month outcomes of LOCOMOTIVE registry are presented in this report. ClinicalTrials.gov Identifier: NCT02531230. Methods: The LOCOMOTIVE study (Multi-LOC for flOw liMiting Outcomes after POBA and/or DCB Treatment in the infrainguinal position with the objecIVE to implant multiple stent segments) investigates the efficacy and safety of the MSDS approach in an all-comers population. Clinical follow-ups at 6 and 12 months are scheduled to assess TLR, ABI, and vessel patency based on sonographic imaging. Results: At 12 months, the primary unassisted patency was 85.7% and all-cause TLR rate was 9.3% in the overall cohort. Between baseline and 12 months, the target leg ABI increased from 0.62 ± 0.24 to 0.91 ± 0.38 (p < 0.001) and the mean Rutherford class improved from 3.5 to 1.9 (p < 0.001). Conclusions: Over a 12-month post-procedural period, MSDS for focal provisional stenting of complex femoropopliteal lesions demonstrated a promising primary patency and freedom from TLR after 12 months. In addition, significant improvements were observed in symptom classification and hemodynamics.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Arterial Phase CTA Replacement by a Virtual Arterial Phase Reconstruction from a Venous Phase CTA: Preliminary Results Using Detector-Based Spectral CT

Objective: To assess the feasibility of creating virtual monoenergetic arterial images from venous phase CTA obtained on a detector-based spectral CT scanner and quantitatively compare the signal-to-noise (SNR) and contrast-to-noise (CNR) ratios of the major arteries to those on polyenergetic true arterial phase images. Methods: In this retrospective study, 23 patients (15 men and 8 women, median age 68 years) who underwent triple-phase CTA on a spectral CT scanner for aortic endograft surveillance were included. The venous phase CTA of each study was reconstructed to generate virtual monoenergetic images at various keV, which were compared to true arterial phase CTA images. SNR and CNR of the aortoiliac arteries were evaluated by testing the differences in means and non-inferiority of virtual arterial images to true arterial images. Effective radiation dose was calculated for standard triple-phase studies in comparison with dual-phase and single-phase spectral CT examinations. Results: Virtual monoenergetic images demonstrated non-inferior (P < 0.05) arterial SNR and CNR compared to true arterial images at 40 keV for all arteries, at 45–50 keV for the thoracic and suprarenal aorta, and at 45–55 keV for the infrarenal aorta and iliac arteries. Significantly higher (P < 0.05) arterial attenuation was obtained at 40 keV for the aortoiliac arteries. Mean effective dose for conventional triple-phase studies was 32.5 mSv in comparison with 21.3 mSv for dual-phase non-contrast/venous scans and 11.3 mSv for single-phase venous scans. Conclusions: Detector-based spectral CT enables creation of virtual monoenergetic arterial images from venous phase CTA with equivalent and in some cases significantly higher SNR/CNR of major arteries compared to images from true arterial phase polyenergetic CTA.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Prospective Study on Total Fluoroscopic Time in Patients Undergoing Uterine Artery Embolization: Comparing Transradial and Transfemoral Approaches

Purpose: Comparing total fluoroscopy time (FT) to perform uterine artery embolization (UAE) with transradial approach (TRA) versus transfemoral approach (TFA). Our hypothesis was that there would be no significant procedural time penalty incurred, despite the learning curve associated with adopting a new approach. Materials and Methods: A cohort study was undertaken including 66 consecutive patients undergoing UAE with either TRA/TFA between January and September 2015. Total FT was recorded prospectively for each procedure, and data subsequently analyzed retrospectively. Each operator had at least 2 years of experience as an interventional radiologist having performed at least 200 TFA UAEs. All operators had recently incorporated TRA into their practice. Results: A total of 39 TFA and 27 TRA cases were included in the study; mean age for TFA group was 44.4 years (± 4.9) and for TRA group was 45.1 years (± 4.9) (p = 0.59). Mean FTs were comparable between the two groups (p = 0.86) despite a learning curve associated with TRA: The mean total FT with TFA was 20.36 min (± 9.48) compared to TRA 20.12 min (± 7.67). Conclusions: FTs for TRA UAE were comparable to TFA UAE, even though TRA had been recently adopted as a new approach. Despite the learning curve associated with developing a novel technique, operators should not expect the efficiency of their service to be significantly compromised. Introducing this safe and effective method of vascular access should therefore be considered.

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DOE OSTI2019

Zilver PTX Post-market Surveillance Study of Paclitaxel-Eluting Stents for Treating Femoropopliteal Artery Disease in Japan: 2-Year Results

Purpose: A prospective, multicenter post-market surveillance study in Japan evaluated the 2-year safety and effectiveness of the DES in real-world patients with complex femoropopliteal artery lesions. Methods: There were no exclusion criteria, and consecutive symptomatic patients with femoropopliteal lesions treated with the DES were enrolled in the study. Clinically driven target lesion revascularization (TLR) was defined as reintervention performed for > 50% diameter stenosis after recurrent clinical symptoms of peripheral arterial disease. Clinical benefit was defined as freedom from persistent or deteriorating ischemic symptoms. Patency was evaluated by duplex ultrasound where physicians considered this standard of care. Results: In this study, 905 patients were enrolled at 95 institutions in Japan. There were numerous comorbidities including a high incidence of diabetes (58.8%) and chronic kidney disease (43.6%). Additionally, 21.4% of patients were classified with critical limb ischemia. Lesions were complex, with an average length of 14.6 ± 9.6 cm (range 0.5–40 cm), 41.5% total occlusions, and 18.7% in-stent restenosis. In total, 1861 DES were placed in 1080 lesions. Two-year follow-up was obtained for > 90% of eligible patients. Freedom from TLR was 83.7%, and clinical benefit was 80.0% through 2 years. The 2-year primary patency rate was 70.3%. Rutherford classification significantly improved (p < 0.01), with approximately 80% of patients classified as Rutherford class 0 or 1 at 2 years. Conclusion: Despite more challenging lesion characteristics, 2-year results from the current study are similar to outcomes from the previous Zilver PTX studies, confirming the efficacy of the Zilver PTX DES in a complicated femoropopliteal lesion (Zilver PTX Post-Market Study in Japan; NCT02254837). Level of Evidence: Post-market surveillance study, Level III.

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