389 research outputs found
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Accuracy of Length of Virtual Stents in Treatment of Intracranial Wide-Necked Aneurysms.
Background and purposePrecise stent deployment is important for successful treatment of intracranial aneurysms by stent-assisted coiling (SAC). We evaluated the accuracy of virtual stents generated using commercial stent planning software by comparing the length of virtual and actually deployed intracranial laser cut stents on three-dimensional digital subtraction angiography (3D-DSA) images.MethodsWe retrospectively analyzed the data of 75 consecutive cases of intracranial wide-necked aneurysms treated with the SAC technique using laser cut stents. Based on 3D-DSA images acquired by C-arm CT, stent sizing and placement were intraoperatively simulated by a commercial software application. The difference in length of the stents was estimated by measuring proximal discrepancies between the end points of the virtual and actually deployed stents on fused pre-procedural and post-procedural 3D-DSA images. Discrepancies between distal stent end points were manually minimized. The Kruskal-Wallis test was applied to test whether stent location, type, and length had an effect on difference in length between virtual and real stent.ResultsThe median difference in length between virtual and real stents was 1.58 mm with interquartile range 1.12-2.12 mm. There was no evidence for an effect of stent location (p = 0.23), stent type (p = 0.33), or stent length (p = 0.53) on difference in length between virtual and real stents.ConclusionsStent planning software allows 3D simulation of laser cut stents overlain on 3D-DSA images of vessels and may thus be useful for stent selection and deployment of laser cut stents during stent-assisted coiling of intracranial aneurysms
Estimated pretreatment hemodynamic prognostic factors of aneurysm recurrence after endovascular embolization.
BACKGROUND:Hemodynamic factors play important roles in aneurysm recurrence after endovascular treatment. OBJECTIVE:Predicting the risk of recurrence by hemodynamic analysis using an untreated aneurysm model is important because such prediction is required before treatment. METHODS:We retrospectively analyzed hemodynamic factors associated with aneurysm recurrence from pretreatment models of five recurrent and five stable posterior communicating artery (Pcom) aneurysms with no significant differences in aneurysm volume, coil packing density, or sizes of the dome, neck, or Pcom. Hemodynamic factors of velocity ratio, flow rate, pressure ratio, and wall shear stress were investigated. RESULTS:Among the hemodynamic factors investigated, velocity ratio and flow rate of the Pcom showed significant differences between the recurrence group and stable group (0.630 ± 0.062 and 0.926 ± 0.051, P= 0.016; 56.4 ± 8.9 and 121.6 ± 6.7, P= 0.008, respectively). CONCLUSIONS:Our results suggest that hemodynamic factors may be associated with aneurysm recurrence among Pcom aneurysms. Velocity and flow rate in the Pcom may be a pretreatment prognostic factor for aneurysm recurrence after endovascular treatment
Unidirectional Laser Emission from Spiral-Shaped Microdisk Based on Conducting Polymer
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Combination of high-resolution cone beam computed tomography and metal artefact reduction software: a new image fusion technique for evaluating intracranial stent apposition after aneurysm treatment.
We introduce a new imaging technique to improve visualisation of stent apposition after endovascular treatment of brain aneurysms employing high-resolution cone beam CT and three-dimensional digital subtraction angiography. After performing a stent-assisted coil embolisation of brain aneurysm, the image datasets were processed with a metal artefact reduction software followed by the automated image fusion programmes. Two patients who underwent aneurysm coiling using a Neuroform stent were evaluated. The reconstructed 3D images showed a detailed structure of the stent struts and identified malappositions of the deployed stents. Case 1 showed good apposition on the outer curvature side of the carotid siphon, while the inner curvature side showed prominent malapposition. Case 2, with multiple aneurysms, showed good apposition on both outer and inner curvature sides, although inward prolapse of the struts was observed. This new imaging technique may help evaluate stent apposition after the endovascular aneurysm treatment
RCABench: Open Benchmarking Platform for Root Cause Analysis
Fuzzing has contributed to automatically identifying bugs and vulnerabilities
in the software testing field. Although it can efficiently generate crashing
inputs, these inputs are usually analyzed manually. Several root cause analysis
(RCA) techniques have been proposed to automatically analyze the root causes of
crashes to mitigate this cost. However, outstanding challenges for realizing
more elaborate RCA techniques remain unknown owing to the lack of extensive
evaluation methods over existing techniques. With this problem in mind, we
developed an end-to-end benchmarking platform, RCABench, that can evaluate RCA
techniques for various targeted programs in a detailed and comprehensive
manner. Our experiments with RCABench indicated that the evaluations in
previous studies were not enough to fully support their claims. Moreover, this
platform can be leveraged to evaluate emerging RCA techniques by comparing them
with existing techniques.Comment: Accepted by NDSS 2023 Workshop on Binary Analysis Research (BAR);
Best Paper Awar
Assembly of Massive Galaxies in a High-z Protocluster
We present the results of wide-field deep JHK imaging of the SSA22 field
using MOIRCS instrument equipped with Subaru telescope. The observed field is
112 arcmin^2 in area, which covers the z=3.1 protocluster characterized by the
overdensities of Ly Alpha emitters (LAEs) and Ly Alpha Blobs (LABs). The 5
sigma limiting magnitude is K_{AB} = 24.3. We extract the potential
protocluster members from the K-selected sample by using the multi-band
photometric-redshift selection as well as the simple color cut for distant red
galaxies (DRGs; J-K_{AB}>1.4). The surface number density of DRGs in our
observed fields shows clear excess compared with those in the blank fields, and
the location of the densest area whose projected overdensity is twice the
average coincides with the large-scale density peak of LAEs. We also found that
K-band counterparts with z_{phot} = 3.1 are detected for 75% (15/20) of the
LABs within their Ly Alpha halo, and the 40 % (8/20) of LABs have multiple
components, which gives a direct evidence of the hierarchical multiple merging
in galaxy formation. The stellar mass ofLABs correlates with their luminosity,
isophotal area, and the Ly Alpha velocity widths, implying that the physical
scale and the dynamical motion of Ly Alpha emission are closely related to
their previous star-formation activities. Highly dust-obscured galaxies such as
hyper extremely red objects (HEROs; J-K_{AB}>2.1) and plausible K-band
counterparts of submillimeter sources are also populated in the high density
region.Comment: 21pages, accepted for publication in Astrophysical Journa
Ureterolithotripsy for a Ureteral Calculus at the Ureteroureterostomy of a Renal-transplant Recipient
We describe a 40-year-old living-donor renal-transplant recipient who underwent successful ureterolithotripsy. He had been on hemodialysis for >15 years pre-transplant and underwent ureteroureterostomy along with the surgery. One year post-transplant, ultrasound examination demonstrated hydronephrosis, and CT showed a 6-mm ureteral calculus at the ureteroureterostomy site. No pain and no elevated serum creatinine were present. As the ureter was easily accessed, we performed a ureterolithotripsy, which would confirm whether a suture caused the calculus. Despite ureteral tortuosity, laser stone fragmentation succeeded. The calculus was completely removed with an antegrade guidewire. Mild postoperative ureteral stenosis resolved with a temporary ureteral stent without balloon dilation. Ureterolithotripsy is effective even in renal transplant recipients with ureteroureterostomy
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