Large Volume Coils Research Articles

Endovascular treatment of medium and large intracranial aneurysms with large volume coils: A single-center experience.

Background: Large volume coils are an alternative to conventional coils for the treatment of intracranial aneurysms. However, there are no published reports documenting occlusion and complication rates in medium and large intracranial aneurysms. Therefore, we present our results in this subgroup of aneurysms.Methods: A single-center, retrospective analysis of consecutive patients treated with Penumbra coils 400 in aneurysms ≥7 mm was performed. Demographics, aneurysm features, procedural details, intraoperative complications, clinical outcomes, and occlusion rates were analyzed.Results: Thirty-three patients were included for analysis, and a total of 33 intracranial aneurysms were analyzed. Mean age was 57.6 years (SD ± 12.4) and 85% of the patients were women. Large aneurysms represented 46% of cases. Paraclinoid (55%) followed by posterior communicating (30.3%) aneurysms was the most frequently treated. Ruptured and saccular aneurysms were found in 49% and 63% of the cases, respectively. The mean aneurysmal dimensions were 14.2 mm width, 11.9 mm length, 5.4 mm neck, and 2.4 dome-to-neck ratio. A dome-neck ratio <2 was identified in 39% of cases. The mean number of coils per aneurysm was 4.8. Immediate modified Raymond–Roy Grades 1, 2, and 3A were achieved in 15%, 21%, and 64%, respectively. Twenty-six patients were evaluated at a mean follow-up period of 11 months, with an adequate occlusion of 92% and a good clinical outcome (modified Rankin score ≤2) in 96% of patients.Conclusion: Endovascular treatment with PC400 coils is an effective and safe option for medium and large intracranial aneurysms with high occlusion rates, few complications, and good clinical outcomes at follow-up.

Abstract 1122‐000060: Endovascular Treatment of Large Intracranial Aneurysms Using Large Volume Coils: Safety and Efficacy

Introduction : Large volume coils in the treatment of intracranial aneurysms have demonstrated better packing density, shorter operative times, less number of coils per aneurysm and better cost‐effectiveness. However, most of the studies evaluated these coils in small or medium sized aneurysms. Therefore, our study aimed to determine our experience using large volume coils in the treatment of large intracranial aneurysms and determine its safety and efficacy. Methods : We retrospectively reviewed consecutive cases of intracranial aneurysms treated with Penumbra Coils 400 (PC400) at our institution between May 2016 and September 2019. Aneurysms &gt; 12 mm in maximal diameter were selected according to the ISUIA trial. Clinical and radiological variables were collected. The modified Rankin Scale (mRS) was used to determine the clinical outcome and was dichotomized (good clinical outcome: mRS £2; poor clinical outcome: mRS &gt;2). The Raymond Roy occlusion classification (RROC) was used to determine obliterations rates. An adequate obliteration was defined as RROC 1 or 2. Categorical variables were expressed as percentages and continuous variables as mean ± standard deviation. Stata v14 software was used for the analysis. Results : Eighteen patients harboring 18 intracranial aneurysms were treated. The mean age was 55 ± 12 years and 14 patients (78%) were women. A good preoperative clinical condition was found in 13 patients (72%). Ten aneurysms were unruptured (56%) and eight were dysplastic (44%). Paraclinoid aneurysms were the most frequently treated (61%). The mean number of coils were 6.2/aneurysm. The mean maximal diameter and neck were 18.9 ± 4.3 mm, and 5.7 ± 2.6 mm, respectively. The mean aspect ratio (AR) was 4 ± 1.9. Coiling was used in 10 cases (56%) followed by stent‐assisted coiling in 7 cases (39%) and balloon‐assisted coiling in 1 case. An immediate adequate obliteration rate was found in 8 cases (44%). Intraoperative complications occurred in two patients in which a coil loop migrated to the parent artery and a stent was placed without clinical consequences. In twelve patients (67%), angiographic follow‐up was performed. The mean follow‐up duration was 9.7 months. Nine patients (75%) showed a complete obliteration (RROC 1), whereas in three patients a residual aneurysm was still present. A good postoperative clinical outcome at discharge was found in 14 patients (78%). Procedure‐related morbidity and mortality were not reported. Conclusions : Embolization with large volume coils is a safe and effective alternative to conventional coils, with high obliteration rates at mid‐term follow‐up. Longer duration of angiographic follow‐up are needed in order to confirm the results presented here.

Proton-decoupled carbon magnetic resonance spectroscopy in human calf muscles at 7 T using a multi-channel radiofrequency coil

13C magnetic resonance spectroscopy is a viable, non-invasive method to study cell metabolism in skeletal muscles. However, MR sensitivity of 13C is inherently low, which can be overcome by applying a higher static magnetic field strength together with radiofrequency coil arrays instead of single loop coils or large volume coils, and 1H decoupling, which leads to a simplified spectral pattern. 1H-decoupled 13C-MRS requires RF coils which support both, 1H and 13C, Larmor frequencies with sufficient electromagnetic isolation between the pathways of the two frequencies. We present the development, evaluation, and first in vivo measurement with a 7 T 3-channel 13C and 4-channel 1H transceiver array optimized for 1H-decoupled 13C-MRS in the posterior human calf muscles. To ensure minimal cross-coupling between 13C and 1H arrays, several strategies were combined: mutual magnetic flux was minimized by coil geometry, two LCC traps were inserted into each 13C element, and band-pass and low-pass filters were integrated along the signal pathways. The developed coil array was successfully tested in phantom and in vivo MR experiments, showing a simplified spectral pattern and increase in signal-to-noise ratio of approximately a factor 2 between non-decoupled and 1H-decoupled spectra in a glucose phantom and the human calf muscle.

Abstract W P71: Analysis of Large Volume Penumbra PC400 Coil and 025” ID Microcatheter in Treatment of Anterior Communicating Artery Aneurysm Embolization: Safety and Efficacy Outcomes from a Multicenter Experience

Purpose: We report clinical experience and long-term results in treating 39 AcomA aneurysms in 39 patients using the Penumbra PC400 large volume coil at 13 high volume centers. With its .020” coil size and use of 025” ID microcatheter, the safety and efficacy of the Penumbra Coil 400 (PC400) System in embolization of AcomA aneurysms has not yet been characterized. Methods: Our treatment cohort consisted of 39 aneurysms ranging between 3.5mm and 17mm, treated between March 2012 and May 2014. Six-month follow up were assessed. Data on angiographic results and procedural complications were collected prospectively and analyzed. Results: The mean aneurysm size was 6.2 mm, with 40.8% mean packing density. All aneurysms were treated entirely with PC400 coils, with mean of 5.1 coils placed. Twenty were ruptured and 19 unruptured. Sixty-six percent of the cases achieved an initial Raymond Scale of 1, and 23.7% achieved a Raymond scale of 2. The overall rate of retreatment was 0%, while the rate of morbidity and mortality caused by stroke &lt;30 days was 1.8%. Comparison with a recently published meta-analysis showed similar or superior outcomes with lower procedural complication rates, most notably lower overall vasospasm rate of 6% vs 17% (p=0.023), lower retreatment rate of 0% vs 9% and higher long-term complete and near-complete occlusion of 96% vs 83% with PC400 coils (Tables 1, 2). Conclusion: ACE study data demonstrate that embolization using the PC400 System and 025” ID microcatheter in AcomA aneurysms leads to safe and effective short- and long-term outcomes.

P-001 Initial Multicentre Clinical Experience with Treating Small Aneurysms (

Introduction/PurposeWe report clinical experience and long-term follow-up results in treating 24 small aneurysms in 22 patients, ranging from 2mm to 4.4mm, using the Penumbra PC400 Large Volume Coil at 4...

P-028 Clinical experience and lessons learned with the penumbra PC 400 large volume coil: improving the treatment of both large and small aneurysms

ObjectiveWe report our clinical experience in treating 34 aneurysms in 29 patients using the Penumbra PC400 Large Volume Coil.Clinical presentation and treatmentOur treatment population consisted of four large (10–25 mm)...

WE-G-217A-05: Automatic Method for RF Coil Assessment in Clinical MRI: A Three-Dimensional Approach.

MRI RF coil assessment is usually evaluated with region-of-interest (ROI) analysis from a single 2D phantom image. This simple approach has worked well for large volume coils or phased-array coil with large receivers, but not the high density phased-array coils characterized by 3D array arrangement of their multiple receivers. This abstract proposes a novel approach for quantitative coil assessment based on 3D imaging and 3D ROI analysis. To characterize all receivers of the coil of interest, a large uniform phantom (preferably a corresponding anthropometric phantom) and a large 3D geometric coverage fully includes the coil sensitivity volume was applied during MR imaging. After imaging, data from all receivers were used to reconstruct a composite 3D image, and to reconstruct 3D images from each individual receiver, leading to a total of N+1 3D image datasets (where N is the number of coil channels). IDL programs were developed to automatically perform ROI analysis on the composite image and on the individual receiver images. Instead of choosing one single 2D slice out of each 3D dataset, the whole 3D dataset was treated as a 3D image, and 3D ROIs were automatically generated for coil assessment. This 3D coil evaluation approach could be applied to all clinical coils including quadrature body/head coils, and phased-array coils with 2 to 32 channels. 3D sensitivity map could be generated to check receiver function visually. 3D mean SNR, max SNR, and uniformity could be obtained from composite and individual channel 3D images fully automatically. Coil/receiver performance assessment was very fast and straightforward, regardless of the number of receivers of the coil. 3D imaging in combination with 3D automatic ROI analysis is a fast, convenient, and less subjective approach for quantitative coil assessment, particularly for high density phased-array coils.

Measurement of dilute 29Si species in solution using a large volume coil and DEFT NMR

A large-sample-volume nuclear magnetic resonance (NMR) spectroscopy probehead has been developed for the detection and characterization of low concentrations of 29Si species in aqueous solution. The approach described entails the use of a large-diameter radio frequency solenoid coil that permits substantially larger sample volumes to be investigated at moderate magnetic field strengths, compared with conventional NMR probehead configurations. In addition, difficulties presented by long 29Si T1 relaxation times have been circumvented by using the DEFT NMR pulse sequence, which permits more rapid signal averaging. Through a combination of these hardware and methodological improvements, high-resolution 29Si NMR spectra have been obtained at 4.2 T (29Si resonance frequency = 36.8 MHz) for an 800 microM solution of 96% 29Si-enriched silicic acid, H4SiO4 (pH approximately 8), with a signal-to-noise ratio of 16 and a line width of 31 Hz after 3 h of total measurement time.