Freestanding Penta-Twinned Pd-Ag Nanosheets.

2D metal nanosheets have attracted significant attention as efficient catalysts for various important chemical reactions. However, the development of metal nanosheets with controlled compositions and morphologies has been slow due to the challenges associated with synthesizing thermodynamically unfavorable 2D structures. Herein, we report a synthesis route of freestanding Pd-Ag penta-twinned nanosheets (Pd-Ag ptNSs) with distinct 5-fold twin boundaries. Through the coreduction of Ag and Pd precursors on presynthesized Pd ptNSs, Ag could be homogeneously alloyed with Pd, leading to the formation of well-defined Pd-Ag ptNSs. The promotional effects of the bimetallic composition, 2D structure, and twin boundaries on catalysis were studied by using Pd-Ag ptNS-catalyzed H2 production from formic acid decomposition as a model reaction. Notably, the catalytic activity of the Pd-Ag ptNSs drastically outperformed those of monometallic, bimetallic, and 3D counterparts, such as Pd ptNSs, Pd-Ag nanosheets without a TB, and Pd-Ag octahedral nanocrystals, demonstrating the promising potential of the integration of twin boundaries and multiple compositions in the development of high-performance 2D nanocatalysts.

Impact of Respiratory Phase during Pleural Puncture on Complications in CT-Guided Percutaneous Lung Biopsy.

Purpose: This study investigated whether the respiratory phase during pleural puncture in CT-guided percutaneous transthoracic needle biopsy (PTNB) affects complications. Materials and Methods: We conducted a retrospective review of 477 lung biopsy CT scans performed during free breathing. The respiratory phases during pleural puncture were determined based on the table position of the targeted nodule using CT scans obtained during free breathing. We compared the rates of complications among the inspiratory, mid-, and expiratory respiratory phases. Logistic regression analysis was performed to control confounding factors associated with pneumothorax. Results: Among the 477 procedures, pleural puncture was performed during the expiratory phase in 227 (47.6%), during the mid-phase in 108 (22.6%), and during the inspiratory phase in 142 (29.8%). The incidence of pneumothorax was significantly lower in the expiratory puncture group (40/227, 17.6%; p = 0.035) and significantly higher in the mid-phase puncture group (31/108, 28.7%; p = 0.048). After controlling for confounding factors, expiratory-phase puncture was found to be an independent protective factor against pneumothorax (odds ratio = 0.571; 95% confidence interval = 0.360-0.906; p = 0.017). Conclusion: Our findings suggest that pleural puncture during the expiratory phase may reduce the risk of pneumothorax during image guided PTNB.

Persistent Primitive Olfactory Artery Type 4 with Fusiform Aneurysm: A Case Report.

The persistent primitive olfactory artery (PPOA) is a rare variant of the anterior cerebral artery, first reported in 1979. It reportedly has a high correlation with the development of aneurysms, owing to the hemodynamic stress induced by the structural characteristics of the hairpin turn. Herein, we present a rare case of PPOA type 4 with a fusiform aneurysm at the hairpin turn segment in a 46-year-old female with occasional headaches. Time-of-flight MR angiography and transfemoral cerebral angiography revealed an unusual branch arising from the left A1 segment, running anteromedially along the ipsilateral olfactory tract, and turning the hairpin posterior to the olfactory bulb. This branch continued into the left accessory middle cerebral artery, and a fusiform aneurysm was observed at the hairpin segment. No further treatment was performed, and follow-up imaging was recommended. Nevertheless, it is essential to recognize and diagnose these rare variations.

Correlation between contrast leakage period of procedural rupture and clinical outcomes in endovascular coiling for cerebral aneurysms.

OBJECTIVE: Intraprocedural rupture (IPR) is a fatal complication of endovascular coiling for cerebral aneurysms. We hypothesized that contrast leakage period may be related to poor clinical outcomes. This study aimed to retrospectively evaluate the relationship between clinical outcomes and contrast leakage period. METHODS: Data from patients with cerebral aneurysms treated via endovascular coiling between January 2010 and October 2018 were retrospectively assessed. The enrolled patient's demographic data, the aneurysm related findings, endovascular treatment and IPR related findings, rescue treatment, and clinical outcome were analyzed. RESULTS: In total, 2,859 cerebral aneurysms were treated using endovascular coiling during the study period, with IPR occurring in 18 (0.63 %). IPR occurred during initial frame coiling (n=4), coil packing (n=5), stent deployment (n=7), ballooning (n=1), and microcatheter removal after coiling (n=1). Tear sites included the dome (n=14) and neck (n=4). All IPRs were controlled and treated with coil packing, with or without stenting. Flow arrest of the proximal balloon was not observed. Temporary focal neurological deficits developed in two patients (11.1%). At clinical follow-up, 14 patients were classified as modified Rankin Scale (mRS) 0, three as mRS 2, and one as mRS 4. The mean contrast leakage period of IPR was 11.2 min (range: 1-31 min). Cerebral aneurysms with IPR were divided into late (n=9, mean time: 17.11 min) and early (n=9, mean time: 5.22 min) control groups based on the criteria of 10 min of contrast leakage period. No significant between-group differences regarding clinical outcomes were observed after IPR (p=1). CONCLUSIONS: In our series, all patients with IPR were controlled with further coil packing or stenting without proximal balloon occlusion within 31 min of contrast leakage. There was no difference in clinical outcomes when the long contrast leakage period group and short contrast leakage period group were compared.

The efficacy and efficiency of percutaneous lidocaine injection for minimizing the carotid reflex in carotid artery stenting: A single-center retrospective study.

Objective: To assess whether local anesthetic infiltration could minimize the carotid baroreceptor reflex (CBR) which has an incidence after carotid artery stenting (CAS) that varies from 29% to 51%. Methods: This retrospective single-center study included 51 patients (mean age, 70.47 years) who underwent CAS for carotid stenosis. The groups included patients who underwent CAS for asymptomatic ischemic stroke (n=41) or symptomatic disease (n=10). Preprocedural percutaneous lidocaine injections (PPLIs) were administered to 70.6% and 5.9% of patients who underwent elective CAS and emergency CAS, respectively. Results: Among patients who received PPLIs, the mean degree of stenosis was 80.5% (95% confidence interval [CI]: ±10.74, 51-98%). The mean distance from the common carotid artery bifurcation to the most stenotic lesion (CSD) was 8.3 mm (95% CI: ±0.97, 6.3-10.2 mm); the mean angle between the internal carotid artery and common carotid artery (CCA) trunk (IAG) was 65.6° (95% CI: ±2.39, 61-70°). Among patients who did not receive PPLIs, the mean degree of stenosis was 84.0% (95% CI: ±8.96, 70-99%). The mean CSD was 5.9 mm (95% CI: ±1.83, 1.9-9.9 mm); the mean IAG was 60.4° (95% CI: ±4.41, 51-70°). The procedure time was longer in the PPLI group than in the no PPLI group (28.19 [n=39] vs. 18.88 [n=12] days) (P=0.057); the length of intensive care unit stay was shorter in the PPLI group (20.01 [n=36] vs. 28.10 [n=5] days) (P=0.132). Conclusions: Targeted PPLI administration to the carotid bulb decreased aberrant heart rates and blood pressure changes induced by carotid stent deployment and balloon inflation. As CBR sensitivity increases with decreasing distance to the stenotic lesion from the CCA bifurcation, PPLIs may help stabilize patients during procedures for stenotic lesions closer to the CCA.

Gerstmann-Sträussler-Scheinker Disease: A Case Report.

Gerstmann-Sträussler-Scheinker (GSS) disease is a rare hereditary prion disease which is clinically characterized by a progressive cerebellar ataxia followed by cognitive impairment. We report a rare case of GSS disease in a 39-year-old male patient who complained of a progressive gait disturbance followed by dysarthria with cognitive impairment, after five months from the onset of initial symptom. His brain MRI scan revealed multifocal symmetric diffusion restricted lesions with T2/FLAIR hyperintensities in bilateral cerebral cortices, basal ganglia, and thalami. His family members also manifested similar symptoms in their 40-50s, suggesting the possibility of a genetic disease. Finally, he was genetically diagnosed with GSS disease by real-time quaking-induced conversion and prion protein (PRNP) gene sequencing test.

Effect of the respiratory motion of pulmonary nodules on CT-guided percutaneous transthoracic needle biopsy.

BACKGROUND: Computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) is highly affected by respiratory motion; however, respiratory motion of target nodule during the PTNB and its effect on CT-guided lung biopsy have not been studied. PURPOSE: To investigate the effect of the respiratory motion of pulmonary nodules on CT-guided PTNB. MATERIAL AND METHODS: We retrospectively reviewed the procedural CT scans of 426 pulmonary nodules that underwent PTNB during quiet breathing. Maximal and average respiratory motions were measured using the difference of table position of the targeted nodule between multiple procedural scans. Diagnostic performance, complications, and technical factors of PTNB in nodules with large motion (maximal motion >1 cm) were compared with those in nodules with small motion (≤1 cm). RESULTS: The mean maximal and average respiratory motions between tidal volume breathing were 5.4 ± 4.4 and 2.7 ± 2.6 mm, respectively. Sensitivity and accuracy were 93.1% and 96.1% in nodules with large motion, compared with 94.7% and 95.9% in nodules with small motion, respectively. Respiratory targeting (P < 0.001), needle modulation (P < 0.001), motion artifact of target (P < 0.001), target disappearance from scans (P < 0.001), and number of performed CT scans (P < 0.001) were significantly higher in the large motion group, with no significant difference in radiation dose and complications between the groups. CONCLUSION: The respiratory motion of pulmonary nodules during CT-guided PTNB may cause technical difficulties but does not affect diagnostic performance nor complications associated with PTNB.

Usefulness of Pointwise Encoding Time Reduction with Radial Acquisition-Magnetic Resonance Angiography after Endovascular Treatment for Intracranial Aneurysms.

PURPOSE: Imaging follow-up after endovascular treatment is important; however, time-of-flight magnetic resonance angiography (TOF-MRA) has limitations associated with magnetic susceptibility and radiofrequency shielding caused by the stent and coils. We evaluated the diagnostic performance of pointwise encoding time reduction with radial acquisition (PETRA)-MRA after endovascular treatment for intracranial aneurysms. MATERIAL AND METHODS: A total of 186 patients with 211 aneurysms who underwent both pointwise encoding time reduction with radial acquisition- and time-of-flight magnetic resonance angiography in the same imaging session for follow-up after endovascular treatment. We subjectively graded the overall image quality, visualization of treated sites, and occlusion status. RESULTS: Although the overall image quality scores of pointwise encoding time reduction with radial acquisition-magnetic resonance angiography were significantly lower than those of time-of-flight magnetic resonance angiography for both observers (4.04 ± 0.81 vs. 4.85 ± 0.35 [observer 1], 4.60 ± 0.69 vs. 4.94 ± 0.24 [observer 2]) (both P < .001), the visibility of treated sites using pointwise encoding time reduction with radial acquisition-magnetic resonance angiography was significantly better than that of time-of-flight magnetic resonance angiography overall (4.27 ± 0.97 vs. 3.42 ± 1.01; P < .001), in the distal internal carotid artery (4.46 ± 0.79 vs. 3.40 ± 1.00; P < .001), and in the middle cerebral artery (4.19 ± 0.93 vs. 3.08 ± 0.53, P = 0.007). Pointwise encoding time reduction with radial acquisition-magnetic resonance angiography showed a higher area under the curve than time-of-flight magnetic resonance angiography for the evaluation of treated aneurysm occlusion, except for posterior circulation aneurysms. CONCLUSIONS: Pointwise encoding time reduction with radial acquisition-magnetic resonance angiography showed better visualization of treated sites and better diagnostic performance than time-of-flight magnetic resonance angiography for anterior circulation aneurysms. However, Pointwise encoding time reduction with radial acquisition-magnetic resonance angiography showed limitations in the follow-up evaluation of posterior circulation aneurysms.

Isolated Intracranial Rosai-Dorfman Disease Mimicking Meningioma: A Case Report.

Rosai-Dorfman Disease (RDD) is a rare lymphoproliferative disease, and the occurrence of isolated intracranial RDD is extremely rare. Most cases of intracranial RDDs present as dural masses showing homogenous enhancement on MRI, which makes it difficult to differentiate these masses from meningiomas before surgery unless massive cervical lymphadenopathy is observed. We herein report a rare case of isolated intracranial RDD in a 65-year-old male. Brain MRI revealed a well-defined enhancing mass-like lesion involving the right frontal convexity and subtle diffusion restriction. However, only a subtle blush was observed on the preoperative cerebral angiogram. Although instances of isolated intracranial RDD are rare, it should be considered as a potential differential diagnosis when a dural mass with hypovascularity is visualized on the cerebral angiogram.

Is Free Breathing Possible During Computed Tomography-Guided Percutaneous Transthoracic Lung Biopsy? The Clinical Experience in 585 Cases.

OBJECTIVE: The aim of the study was to retrospectively evaluate the safety and accuracy of computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) of lung lesions during quiet breathing. METHODS: We investigated the diagnostic performance and complication rate of 585 procedures in 563 patients (357 men; mean age, 67.7 years), who underwent CT-guided PTNBs during quiet breathing, aided by a respiratory targeting technique from May 2017 to July 2019. Differences between the cases with and without respiratory targeting were analyzed. Logistic regression analyses were performed to examine the development of pneumothorax and hemoptysis. RESULTS: Percutaneous transthoracic needle biopsy samples were successfully obtained in 574 of 585 procedures (98.1%). Final diagnoses included: 410 malignant cases, 119 benign cases, and 45 indeterminate cases. The sensitivity, specificity, and accuracy of diagnosis were 94.4%, 100%, and 95.7%, respectively. Use of respiratory targeting was associated with younger age (P = 0.004), smaller lesion size (P < 0.001), peripheral location (P = 0.003), shorter distance from the diaphragm (P < 0.001), lower lobe location (P < 0.001), prone position (P = 0.004), and visible motion artifact (P < 0.001). Pneumothorax and hemoptysis rates were 22.9% and 7.9%, respectively. Upon multivariate analysis, emphysema (P = 0.002) was the only independent risk factor for pneumothorax, whereas distance from the pleura greater than 2 cm (P < 0.001), tissue sampling 3 times or more (P = 0.003), and a less experienced operator (P < 0.001) were risk factors for hemoptysis. CONCLUSIONS: Computed tomography-guided PTNB during quiet breathing with respiratory targeting yielded high diagnostic performance with a slightly higher rate of complications. Free-breathing PTNB can be applied in clinical practice, based on lesion location and risk factors for complications.

Detection of pericardial flow in black blood-prepared T2 HASTE sequence imaging: Differentiation between pericardial diverticulum and cyst.

Pericardial diverticulum is a focal herniation of the pericardium. It is differentiated from a pericardial cyst by the presence of communication with the pericardial cavity. Radiological differentiation between the diverticulum and cyst via computed tomography is difficult unless changes in size are identified with different body positions in additional scans. Herein we describe a case of pericardial diverticulum that was successfully diagnosed via the detection of internal pericardial flow in black blood-prepared T2 half-Fourier acquisition single-shot turbo spin-echo magnetic resonance imaging. Detection of a flow void in the pericardial sac may be a definitive magnetic resonance imaging finding in the diagnosis of pericardial diverticulum.

Vertebral Artery Dissecting Aneurysm Causing Central Tapia's Syndrome: A Case Report.

The central type of Tapia's syndrome is an extremely rare presentation, characterized by unilateral paralysis of the vagal and hypoglossal nerves, contralateral hemiparesis, or hemihypesthesia. This report describes a case of a middle-aged patient who developed central Tapia's syndrome due to a right vertebral artery dissecting aneurysm (VADA). The patient complained about swallowing difficulty and odynophagia. Right vocal cord paralysis, mild tongue deviation to the right side, left hypesthesia, and decreased temperature sensation with left hemiparesis were observed in neurologic exams. A right VADA and compression of the medulla oblongata due to the VADA were diagnosed on magnetic resonance imaging. Endovascular flow diversion of the right VADA was performed. After 1 year, all neurological symptoms and vocal cord paralysis were nearly resolved, but left hypesthesia remained with decreased nociception. We present and discuss how a VADA caused those symptoms and propose endovascular flow diversion as a treatment option.

Comparison of the Quality of Various Polychromatic and Monochromatic Dual-Energy CT Images with or without a Metal Artifact Reduction Algorithm to Evaluate Total Knee Arthroplasty.

OBJECTIVE: To compare the quality of various polychromatic and monochromatic images with or without using an iterative metal artifact reduction algorithm (iMAR) obtained from a dual-energy computed tomography (CT) to evaluate total knee arthroplasty. MATERIALS AND METHODS: We included 58 patients (28 male and 30 female; mean age [range], 71.4 [61-83] years) who underwent 74 knee examinations after total knee arthroplasty using dual-energy CT. CT image sets consisted of polychromatic image sets that linearly blended 80 kVp and tin-filtered 140 kVp using weighting factors of 0.4, 0, and -0.3, and monochromatic images at 130, 150, 170, and 190 keV. These image sets were obtained with and without applying iMAR, creating a total of 14 image sets. Two readers qualitatively ranked the image quality (1 [lowest quality] through 14 [highest quality]). Volumes of high- and low-density artifacts and contrast-to-noise ratios (CNRs) between the bone and fat tissue were quantitatively measured in a subset of 25 knees unaffected by metal artifacts. RESULTS: iMAR-applied, polychromatic images using weighting factors of -0.3 and 0.0 (P-0.3i and P0.0i, respectively) showed the highest image-quality rank scores (median of 14 for both by one reader and 13 and 14, respectively, by the other reader; p < 0.001). All iMAR-applied image series showed higher rank scores than the iMAR-unapplied ones. The smallest volumes of low-density artifacts were found in P-0.3i, P0.0i, and iMAR-applied monochromatic images at 130 keV. The smallest volumes of high-density artifacts were noted in P-0.3i. The CNRs were best in polychromatic images using a weighting factor of 0.4 with or without iMAR application, followed by polychromatic images using a weighting factor of 0.0 with or without iMAR application. CONCLUSION: Polychromatic images combined with iMAR application, P-0.3i and P0.0i, provided better image qualities and substantial metal artifact reduction compared with other image sets.

Differences between proximal and distal M1 occlusions after mechanical thrombectomy.

PURPOSE: Whether M1 occlusions proximal (pM1) and distal (dM1) to the lenticulostriate perforators result in different clinical outcomes after mechanical thrombectomy (MT) is unknown. We retrospectively compared the clinical outcomes and baseline characteristics of patients with these two types of occlusions. METHODS: From March 2010 to May 2019, we performed MT for 141 M1 occlusions, including pM1 occlusions (n = 58) and dM1 occlusions (n = 83). RESULTS: Good clinical outcomes (modified Rankin Scale score 0 to 2) were achieved in 28 out of 58 (48.3%) patients with pM1 occlusions and 46 out of 83 (55.4%) patients with dM1 occlusions without significance (p = 0.493). Cardioembolic occlusions represented 19 out of 58 (32.6%) pM1 occlusions and 53 out of 83 (63.9%) dM1 occlusions, and atherosclerotic occlusions represented 37 out of 58 (63.8%) pM1 occlusions and 27 out of 83 (32.5%) dM1 occlusions, with significance (p = 0.001). Rescue treatments, such as balloon angioplasty or stenting, were needed more for pM1 occlusions than dM1 occlusions (21 out of 58 (36.2%) vs. 8 out of 83 (9.8%), p < 0.001). The multivariable logistic regression analysis demonstrated that the need for rescue treatment was associated with pM1 occlusions (adjusted odds ratio; 3.804, 95% confidence interval; 1.306-11.082, p = 0.014). CONCLUSIONS: In our series, pM1 and dM1 occlusions did not significantly differ in good clinical outcomes. Our study also showed that pM1 occlusions were more strongly associated with atherosclerotic occlusions, while dM1 occlusions were more strongly associated with cardioembolic occlusions, and rescue treatments were needed more often for pM1 occlusions than dM1 occlusions.

Comparison of the Solitaire and Trevo Stents for Endovascular Treatment of Acute Ischemic Stroke: A Single.Center Experience.

AIMS: Limited studies have compared the effectiveness of Solitaire and Trevo stentrievers for endovascular thrombectomy to achieve recanalization and improve functional outcomes of patients with acute ischemic stroke. Therefore, we compared the safety and efficacy of the two stents during endovascular thrombectomy for patients with acute ischemic stroke. MATERIALS AND METHODS: This study included 130 patients who underwent endovascular thrombectomy using either the Trevo (n = 51) or the Solitaire (n = 79) stent for anterior circulation acute ischemic stroke. Recanalization was classified using thrombolysis in cerebral infarction (TICI) grading. Efficacy and safety of the devices during endovascular thrombectomy were analyzed by evaluating the rate of good recanalization after the first pass, clot retrieval rate, final recanalization grade, use of rescue treatment, recanalization time, and hemorrhagic and thromboembolic complications. RESULTS: Overall, good recanalization (TICI grades 2b and 3) was achieved (Solitaire: n = 57, 72.2%; Trevo: n = 46, 90.2%) (P = 0.01). The rate of good recanalization after the first pass and clot retrieval rate were similar between groups; however, the use of rescue treatment was more frequent in the Solitaire group. Recanalization time was shorter in the Trevo group. The good clinical outcome rate was higher in the Trevo group but not statistically significantly. The rates of symptomatic hemorrhage and thromboembolism were not significantly different between groups. CONCLUSION: The Trevo stent achieved more successful recanalization with less need for rescue treatment and less time for recanalization than the Solitaire stent. There was no statistically significant difference in the clinical outcomes.

Compressed sensing time-of-flight magnetic resonance angiography with high spatial resolution for evaluating intracranial aneurysms: comparison with digital subtraction angiography.

BACKGROUND AND PURPOSE: Compressed sensing is used for accelerated acquisitions with incoherently under-sampled k-space data, and intracranial time-of-flight magnetic resonance angiography is suitable for compressed sensing. Compressed sensing time-of-flight is beneficial in decreasing acquisition time and increasing spatial resolution while maintaining acquisition time. In this retrospective study, we aimed to evaluate the image quality and diagnostic performance of compressed sensing time-of-flight with high spatial resolution and compare with parallel imaging time-of-flight using digital subtraction angiography as a reference. MATERIAL AND METHODS: In total, 39 patients with 46 intracranial aneurysms underwent parallel imaging and compressed sensing time-of-flight in the same imaging session and digital subtraction angiography before or after magnetic resonance angiography. The overall image quality, artefacts and diagnostic confidence were assessed by two observers. The contrast ratio, maximal aneurysm diameters and diagnostic performance were evaluated. RESULTS: Compressed sensing time-of-flight showed significantly better overall image quality, degree of artefacts and diagnostic confidence in both observers, with better inter-observer agreement. The contrast ratio was significantly higher for compressed sensing time-of-flight than for parallel imaging time-of-flight in both observers (source images, P < 0.001; maximum intensity projection images, P < 0.05 for both observers); however, the measured maximal diameters of aneurysms were not significantly different. Compressed sensing time-of-flight showed higher sensitivity, specificity, accuracy and positive and negative predictive values for detecting aneurysms than parallel imaging time-of-flight in both observers, with better inter-observer agreement. Compressed sensing time-of-flight was preferred over parallel imaging time-of-flight by both observers; however, parallel imaging time-of-flight was preferred in cases of giant and large aneurysms. CONCLUSIONS: Compressed sensing-time-of-flight provides better image quality and diagnostic performance than parallel imaging time-of-flight. However, neuroradiologists should be aware of under-sampling artefacts caused by compressed sensing.

CT Follow-Up of Postoperative Bronchopleural Fistula: Risk Factors for Progression to Chronic Complicated Infection.

Purpose: We evaluated the risk factors for progression to chronic complicated bronchopleural fistula (BPF) after pulmonary resection using follow-up CT. Materials and Methods: We retrospectively reviewed 45 cases with BPF that had undergone pulmonary resection during 2010-2018. We compared the clinical and radiological characteristics of those with complicated BPF (n = 24) and those without complicated (sterilized) BPF (n = 21). The clinical and radiological risk factors for progression to chronic complicated BPF were examined by logistic regression analysis. Results: The thickness of the pleural cavity wall (p = 0.022), the size of the pleural cavity (p = 0.029), and the size increase of BPF on follow-up (p = 0.012) were significantly different between the two groups. The risk factors for progression to chronic complicated BPF were age > 70 years (odds ratio, 6.43; 95% confidence interval, 1.2-33.7), the thickness of the cavity wall > 5 mm (odds ratio, 52.5; 95% confidence interval, 5.1-545.4), and an increase in the size of the pleural cavity on follow-up CT (odds ratio, 12.5; 95% confidence interval, 2.1-73.5), only in the univariate analysis. Conclusion: The risk factors for progression to chronic complicated BPF can be evaluated using follow-up CT.

Usefulness of pointwise encoding time reduction with radial acquisition sequence in subtraction-based magnetic resonance angiography for follow-up of the Neuroform Atlas stent-assisted coil embolization for cerebral aneurysms.

BACKGROUND: Although time-of-flight magnetic resonance angiography (TOF-MRA) is widely used, it has limited usefulness for follow-up after stent-assisted coil embolization. Contrast-enhanced MRA (CE-MRA) and ultrashort echo time MRA have been suggested as alternative methods for visualization after this procedure. PURPOSE: To compare efficacy and usefulness of pointwise encoding time reduction with radial acquisition (PETRA) sequence in subtraction-based MRA (qMRA), TOF-MRA, and CE-MRA during the follow-up after Neuroform Atlas stent-assisted coil embolization for intracranial aneurysms. MATERIAL AND METHODS: This retrospective study included 23 patients with 24 aneurysms who underwent Neuroform Atlas stent-assisted coil embolization for intracranial aneurysms. All patients were evaluated with PETRA qMRA, TOF-MRA, and CE-MRA at the same follow-up session. The flow within stents, occlusion status, and presence of pseudo-stenosis were evaluated; inter-observer and intermodality agreements for the three methods were also graded. RESULTS: The mean score for flow visualization within the stents was significantly higher for PETRA qMRA and CE-MRA than for TOF-MRA (although no significant difference was found between PETRA qMRA and CE-MRA). Good inter-observer agreement was observed for each modality. PETRA qMRA and CE-MRA were more consistent with digital subtraction angiography (DSA) than TOF-MRA for aneurysm occlusion status. The intermodality agreement was better between PETRA qMRA and DSA, and between CE-MRA and DSA, than between DSA and TOF-MRA. Pseudo-stenosis was most frequently observed in TOF-MRA, followed by CE-MRA and PETRA qMRA. CONCLUSION: PETRA qMRA is useful for evaluating the parent artery patency and occlusion status of aneurysms after Neuroform Atlas stent-assisted coil embolization.

Differences in thromboembolism after stent-assisted coiling for unruptured aneurysms between aspirin plus clopidogrel and ticagrelor.

PURPOSE: To reduce procedural thromboembolisms, tailored antiplatelet drug preparation has been used according to antiplatelet resistance for endovascular coiling of unruptured aneurysms. We compared an aspirin plus clopidogrel group with a ticagrelor group using diffusion-weighted imaging (DWI) after stent-assisted coiling for unruptured aneurysms. METHODS: From October 2018 to April 2019, 72 patients with 78 aneurysms underwent stent-assisted coiling, with aspirin plus clopidogrel (n = 20 patients with 22 aneurysms) or ticagrelor (n = 52 patients with 56 aneurysms) as an antiplatelet preparation, and were enrolled in our study. All patients were evaluated using DWI 2 h after coiling to detect procedural thromboembolisms. RESULTS: Postprocedure infarction was observed on DWI in 37 procedures (47.4%), and symptomatic infarction occurred in 1 procedure (1.28%). Postprocedure infarction was significantly lower in the aspirin plus clopidogrel than in ticagrelor group (27.3% vs. 55.4%, p = 0.043). Postprocedure infarction was associated with aneurysm type (sidewall aneurysm (30.8%) vs. aneurysm with incorporated branches (64.1%), p = 0.006) and guiding catheter type (single (23.8%) vs. double (56.1%), p = 0.020). Multivariable logistic regression analysis demonstrated that postprocedure infarction was related to aneurysm type (adjusted odds ratio (OR); 3.317, confidence interval (CI); 1.223-8.991, p = 0.018), guiding catheter type (adjusted OR; 2.783, CI; 0.828-9.353, p = 0.098), and antiplatelet medication (adjusted OR; 1.295, CI; 0.969-1.730, p = 0.080). CONCLUSIONS: Postprocedure infarction was observed on DWI after stent-assisted coiling for unruptured aneurysms more frequently in the ticagrelor group than in the aspirin plus clopidogrel group. However, our study suggests that postprocedure infarction is more associated with aneurysm type than antiplatelet medication.

Hybrid mechanical thrombectomy for acute ischemic stroke using an intermediate aspiration catheter and Trevo stent simultaneously.

PURPOSE: To overcome the limitations of traditional mechanical thrombectomy (MT), including catheter aspiration and stent retrievers, such as thrombus fragmentation or migration, we designed hybrid MT using an intermediate aspiration catheter and a Trevo stent simultaneously. We retrospectively compared hybrid MT with the traditional MT. METHODS: From January 2017 to January 2019, we performed MT on 91 occlusions, including internal carotid artery bifurcation (n = 17), M1 segment (n = 53) and M2 segment (n = 21), using hybrid MT (n = 42) and traditional MT (n = 49). RESULTS: Hybrid MT had a shorter procedure time (52.4 ± 22.0 vs. 73.0 ± 36.2 min, p = 0.002) and fewer attempts (1.50 ± 0.86 vs. 1.92 ± 1.10 times, p = 0.049) than traditional MT did. Hybrid MT achieved more good clinical outcome (3-month modified Rankin Scale score, 2 or less) and better successful recanalization (Thrombolysis In Cerebral Infarction grade, 2b or 3) than traditional MT did, but the difference was not significant (61.9% vs. 55.1%, p = 0.531, 92.9% vs. 87.8%, p = 0.498). Hybrid MT showed a higher first pass successful recanalization rate than traditional MT did (69.0% vs. 40.8%, p = 0.011). Multivariable logistic regression analysis demonstrated that first pass successful recanalization is related to the M1 segment rather than other segments (adjusted odds ratio (OR); 3.277, confidence interval (CI); 1.227-8.749, p = 0.018) and hybrid MT rather than traditional MT (adjusted OR; 4.995, CI; 1.725-14.460, p = 0.003). CONCLUSIONS: Hybrid MT can be used as a first-line MT modality, particularly in M1 occlusion, based on our high first pass successful recanalization results.