Efficacy of high-resolution vessel wall MRI in the postoperative assessment of intracranial aneurysms following flow diversion treatment.

OBJECTIVE: Certain patients must undergo frequent postoperative digital subtraction angiography (DSA) after flow diversion (FD) therapy. No imaging modality with an efficacy comparable to that of DSA has been established. This study was conducted to determine the efficacy of contrast-enhanced delay alternating with nutation for tailored excitation (DANTE) T1-sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE), a high-resolution vessel wall magnetic resonance imaging technique for evaluating the occlusion status of intracranial aneurysms after FD treatment, with DSA serving as the reference standard. METHODS: This retrospective study included 23 patients with 26 aneurysms who had undergone FD treatment between April 2016 and May 2022. Contrast-enhanced DANTE T1-SPACE and DSA were performed as postoperative follow-up imaging studies at 45 time points, both in the same period. The agreement rates for aneurysm occlusion status in the 45 imaging studies were examined. RESULTS: Contrast-enhanced DANTE T1-SPACE had a sensitivity and specificity of 96.3% (26/27) and 83.3% (15/18), respectively, for detecting aneurysm remnants. Overall, 91.1% (41/45) of findings detected on contrast-enhanced DANTE T1-SPACE were consistent with those on DSA. The findings detected on contrast-enhanced DANTE T1-SPACE were completely consistent with those of intraaneurysmal residual blood flow identified on DSA or high-resolution cone-beam computed tomography images in 74.1% (20/27) of the examinations that showed incomplete occlusion on DSA. Furthermore, parent artery status after FD treatment on contrast-enhanced DANTE T1-SPACE was consistent with that observed on DSA in 97.8% (44/45) of examinations. CONCLUSIONS: Contrast-enhanced DANTE T1-SPACE is a very useful option in the follow-up of aneurysms after FD treatment.

Spinal epidural arteriovenous fistula with an intraosseous shunt arising in a compression fracture vertebra: illustrative case.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEAVFs) with intraosseous shunts are rare, and their underlying pathophysiological mechanisms remain unclear. OBSERVATIONS: A female in her 70s presented with rapidly progressive weakness in both lower extremities and urinary retention. Lumbar spine magnetic resonance imaging revealed spinal cord edema and flow voids due to venous dilation and compression fractures of the L1 and L2 vertebral bodies. Spinal angiography revealed ventral and dorsal somatic branches of the lumbar arteries at L1 and L2 flowing into the shunt. High-resolution cone-beam computed tomography revealed a shunt within the compression-fractured vertebral body bone of L2. The intravertebral shunt blood flowed into the ventral epidural venous plexus (VEVP) and returned into the perimedullary vein (PMV). Transarterial embolization was performed using N-butyl cyanoacrylate and Onyx-18 for feeder L1 and feeder L2, respectively. Onyx-18 was injected from the VEVP into the PMV, and complete occlusion of the shunt was achieved. The patient showed symptomatic improvement postoperatively. LESSONS: Vertebral compression fractures are common but rarely associated with SEAVFs. https://thejns.org/doi/10.3171/CASE2457.

Automated evaluation of masseter muscle volume: deep learning prognostic approach in oral cancer.

BACKGROUND: Sarcopenia has been identified as a potential negative prognostic factor in cancer patients. In this study, our objective was to investigate the relationship between the assessment method for sarcopenia using the masseter muscle volume measured on computed tomography (CT) images and the life expectancy of patients with oral cancer. We also developed a learning model using deep learning to automatically extract the masseter muscle volume and investigated its association with the life expectancy of oral cancer patients. METHODS: To develop the learning model for masseter muscle volume, we used manually extracted data from CT images of 277 patients. We established the association between manually extracted masseter muscle volume and the life expectancy of oral cancer patients. Additionally, we compared the correlation between the groups of manual and automatic extraction in the masseter muscle volume learning model. RESULTS: Our findings revealed a significant association between manually extracted masseter muscle volume on CT images and the life expectancy of patients with oral cancer. Notably, the manual and automatic extraction groups in the masseter muscle volume learning model showed a high correlation. Furthermore, the masseter muscle volume automatically extracted using the developed learning model exhibited a strong association with life expectancy. CONCLUSIONS: The sarcopenia assessment method is useful for predicting the life expectancy of patients with oral cancer. In the future, it is crucial to validate and analyze various factors within the oral surgery field, extending beyond cancer patients.

Ruptured thrombosed vertebral artery dissecting aneurysm treated with staged flow diverter after prediction of the rupture point by vessel wall MRI.

The safety and feasibility of using staged flow diverter (FD) for ruptured cerebral aneurysms, in which coil embolization is performed in the acute phase and FD is deployed in the subacute phase, has recently been reported. This strategy requires assuming the rupture point and performing coil embolization. Although vessel wall magnetic resonance imaging (VW-MRI) has been reported to be useful in predicting the rupture point of aneurysms, its use with staged FD has not yet been reported. We report the first case of staged FD with preoperative contrast-enhanced VW-MRI to predict the rupture point for partially thrombosed vertebral artery dissecting large aneurysm involving posterior inferior cerebellar artery (PICA) origin. This approach achieved a very good outcome, not only completely occluding the aneurysm, but also reconstructing the parent artery while maintaining the patency of the PICA.

Partially thrombosed giant basilar artery aneurysm with attenuated contrast enhancement of the intraluminal thrombus on vessel wall MRI after flow diversion treatment: illustrative case.

BACKGROUND: The effect of vessel wall magnetic resonance imaging (VW-MRI) enhancement in partially thrombosed aneurysms has previously indicated aneurysmal instability and a rupture risk. However, whether the contrast effect of the wall changes before or after flow diversion treatment is still under investigation. OBSERVATIONS: The authors report a case of a partially thrombosed basilar artery aneurysm that increased in size over a short period, worsened brainstem compression symptoms, and was treated with a flow diverter stent with good results. In this case, VW-MRI after surgery showed a reduced contrast effect on the intraluminal thrombus within the aneurysm. The aneurysm thrombosed and markedly regressed over the next 5 months, with remarkable improvement in the brainstem compression symptoms. LESSONS: This finding on VW-MRI may indicate an attenuation of neovascularization in the thrombus wall and be a sign of aneurysm stabilization.

Bioresorbable Poly (L-Lactic Acid) Flow Diverter Versus Cobalt-Chromium Flow Diverter: In Vitro and In Vivo Analysis.

BACKGROUND: Permanent metallic flow diverter (FD) implantation for treatment of intracranial aneurysms requires antiplatelet therapy for an unclear duration and restricts postprocedural endovascular access. Bioresorbable FDs are being developed as a solution to these issues, but the biological reactions and phenomena induced by bioresorbable FDs have not been compared with those of metallic FDs. METHODS: We have developed a bioresorbable poly (L-lactic acid) FD (PLLA-FD) and compared it with an FD composed of cobalt-chromium and platinum-tungsten (CoCr-FD). FD mechanical performance and in vitro degradation of the PLLA-FD were evaluated. For in vivo testing in a rabbit aneurysm model, FDs were implanted at the aneurysm site and the abdominal aorta in the PLLA-FD group (n=21) and CoCr-FD group (n=15). Aneurysm occlusion rate, branch patency, and thrombus formation within the FD were evaluated at 3, 6, and 12 months. Local inflammation and neointima structure were also evaluated. RESULTS: Mean strut, porosity, and pore density for the PLLA-FD were 41.7 µm, 60%, and 20 pores per mm2, respectively. The proportion of aneurysms exhibiting a neck remnant or complete occlusion did not significantly differ between the groups; however, the complete occlusion rate was significantly higher in the PLLA-FD group (48% versus 13%; P=0.0399). Branch occlusion and thrombus formation within the FD were not observed in either group. In the PLLA-FD group, CD68 immunoreactivity was significantly higher, but neointimal thickness decreased over time and did not significantly differ from that of the CoCr-FD at 12 months. Collagen fibers significantly predominated over elastic fibers in the neointima in the PLLA-FD group. The opposite was observed in the CoCr-FD group. CONCLUSIONS: The PLLA-FD was as effective as the CoCr-FD in this study and is feasible for aneurysm treatment. No morphological or pathological problems were observed with PLLA-FD over a 1-year period.

Onset-to-treatment time and aneurysmal regression predict improvement of cranial neuropathy after flow diversion treatment in patients with symptomatic internal carotid artery aneurysms.

BACKGROUND: Although flow diversion plays a pivotal role in treating internal carotid artery aneurysms presenting with cranial neuropathy, predictors of symptom improvement have not been established. OBJECTIVE: To investigate improvement of symptoms after flow diversion treatment in patients with internal carotid artery aneurysms causing cranial neuropathy, with sufficient follow-up period. Additionally, to examine factors associated with improvement of symptoms. METHODS: This retrospective multicenter study examined patients with unruptured internal carotid artery aneurysms presenting with cranial neuropathy who were treated using flow diversion and followed up for at least 12 months. Study outcomes were transient worsening of symptoms and symptom status 12 months after treatment. Patient and aneurysm characteristics were statistically analyzed. RESULTS: Seventy-seven patients were included. Data needed for outcome analysis were available for 66 patients. At the 1-, 3-, 6-, 12-month, and last follow-ups, the proportion of patients with resolved or improved symptoms was 26% (20/77), 51% (39/77), 74% (57/77), 83% (64/77), and 79%(62/77), respectively. Symptom onset-to-treatment time <6 months (OR=24.2; 95% CI 3.09 to 188.84; p=0.002) and aneurysmal regression (OR=23.1; 95% CI 1.97 to 271.75; p=0.012) were significantly associated with symptom improvement. Transient symptom worsening and worse symptoms at 12 months occurred in 19/77 (25%) and 2/77 (3%) patients, respectively. CONCLUSIONS: The rate of cranial neuropathy symptom improvement after flow diversion increased over the first 12 months after treatment, but not thereafter. Treatment within 6 months of symptom onset and aneurysmal regression were predictors of symptom improvement.

Machine Learning Analysis of Gaze Data for Enhanced Precision in Diagnosing Oral Mucosal Diseases.

The diagnosis of oral mucosal diseases is a significant challenge due to their diverse differential characteristics. Risk assessment of lesions by visual examination is a complex process due to the lack of definitive guidelines. This study aimed to improve this process by creating a diagnostic algorithm using gaze data acquired during oral mucosal disease examinations. A total of 78 dentists were included in this study. Tobii Pro Nano® (Tobii Technology) was used to acquire gaze data during clinical photographic visual examinations. Advanced analysis tools such as support vector machines and heatmaps were used to visualize the gazing tendencies of a group of skilled oral surgeons, focusing on the number of gazes per region and the gazing time ratios. The preliminary findings showed the possibility of visualizing gazing tendencies and identifying areas of importance for diagnosis. The classification of intraoral photographs based on gross features revealed the existence of an optimal examination method for each category and diagnostically significant areas. This novel approach to analyzing gaze data has the potential to refine diagnostic techniques and increase both accuracy and efficiency.

Predictors of aneurysm shrinkage after flow diversion treatment for internal carotid artery aneurysms: quantitative volume analysis with MRI.

Background and purpose: Although aneurysm shrinkage often occurs after flow diversion treatment for intracranial aneurysms, no reports have addressed the factors associated with aneurysm shrinkage. Materials and methods: This retrospective single-center study was performed to examine patients with unruptured internal carotid artery aneurysms who were treated using flow diversion and followed up by imaging for at least 12 months. The study outcome was aneurysm shrinkage (volume reduction of ≥10%) 12 months after treatment. Aneurysm volume was quantitatively assessed using the MRIcroGL software. Patient and aneurysm characteristics were statistically analyzed. Results: This study involved 81 patients with 88 aneurysms. At the 6 months, 12 months, and last follow-ups, the proportion of aneurysms that had shrunk was 50, 64, and 65%, respectively. No adjunctive coiling (odds ratio, 56.7; 95% confidence interval, 7.03-457.21; p < 0.001) and aneurysm occlusion (odds ratio, 90.7; 95% confidence interval, 8.32-988.66; p < 0.001) were significantly associated with aneurysm shrinkage. In patients treated by flow diversion with adjunctive coiling, only the volume embolization rate was a factor significantly associated with aneurysm shrinkage (p < 0.001). Its cutoff value was 15.5% according to the receiver operating characteristic curve analysis (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.83). Conclusion: The rate of aneurysm shrinkage after flow diversion increased during the first 12 months after treatment, but not thereafter. No adjunctive coiling and aneurysm occlusion were predictors of aneurysm shrinkage, respectively. If adjunctive coiling is required, a volume embolization rate of ≤15.5% may be suggested for aneurysm regression.

Collision-induced torque mediates the transition of chiral dynamic patterns formed by active particles.

Controlling the patterns formed by self-propelled particles through dynamic self-organization is a challenging task. Although varieties of patterns associated with chiral self-propelled particles have been reported, essential factors that determine the morphology of the patterns have remained unclear. Here, we explore theoretically how torque formed upon collision of the particles affects the dynamic self-organization of the particles and determine the patterns. Based on a particle-based model with collision-induced torque and torque associated with self-propulsion, we find that introducing collision-induced torque turns the homogeneous bi-directionally aligned particles into rotating mono-polar flocks, which helps resolve a discrepancy in the earlier observations in microfilament gliding assays.

Developed Circuminfundibular Anastomosis Associated with Vascular Abnormalities.

We report a 74-year-old male patient who presented with left hemiplegia and disturbance of consciousness. Computed tomography revealed diffuse subarachnoid hemorrhage, which was prominent in the right Sylvian and basal cisterns. Digital subtraction angiography revealed absence of the C2 segment of the right internal carotid artery (ICA) and a significantly developed circuminfundibular anastomosis. Occlusion of the bilateral vertebral arteries (VAs) was also seen. The upper basilar artery was supplied by the circuminfundibular anastomosis and collaterals from the VAs. Since the source of bleeding was unclear, the patient was treated conservatively. Circuminfundibular anastomosis is a potential anastomosis around the pituitary stalk. It is formed by the superior hypophyseal arteries, prechiasmal arteries, and infundibular arteries bilaterally. Agenesis of the contralateral ICA often leads to development of ICA-ICA anastomoses. In this case, the anastomosis developed due to agenesis of the C2 segment of the right ICA and occlusion of the bilateral VAs.

Transarterial and Transvenous Embolization for Posterior Condylar Canal Dural Arteriovenous Fistula.

Objective: Posterior condylar canal dural arteriovenous fistula (PCC DAVF) is extremely rare, with only four previously reported cases in the English literature. Cases may present tinnitus and radiculopathy. In cases where the drainer is around the brainstem, subarachnoid and intraventricular hemorrhages (IVHs) may occur. We describe the clinical presentation, angiographic imaging, and endovascular treatment strategy of a PCC DAVF. Case Presentation: A 30-year-old woman presented to our hospital with tinnitus and stiffness of the shoulder. Neuroimaging studies showed DAVF with fistulous points around right PCC consisted of a high-flow shunt, fed mainly by the occipital artery, and drained to the suboccipital cavernous sinus (SCS) and internal jugular vein. The lesion was treated with a combination of transvenous coil embolization and transarterial Onyx injection. The patient recovered immediately after intervention and had no neurological deficits in the follow-up visit. Conclusion: In this case, endovascular treatment was performed safely without recurrence so far. A strategy combining transvenous coil embolization and transarterial Onyx injection may be an effective treatment for PCC DAVF with high-flow shunt. Further case accumulation is desired.

Lateral depletion effect on two-dimensional ordering of bacteriorhodopsins in a lipid bilayer: A theoretical study based on a binary hard-disk model.

The 2D ordering of bacteriorhodopsins in a lipid bilayer was studied using a binary hard-disk model. The phase diagrams were calculated taking into account the lateral depletion effects. The critical concentrations of the protein ordering for monomers and trimers were obtained from the phase diagrams. The critical concentration ratio agreed well with the experiment when the repulsive core interaction between the depletants, namely, lipids, was taken into account. The results suggest that the depletion effect plays an important role in the association behaviors of transmembrane proteins.

Monopolar flocking of microtubules in collective motion.

Flocking is a fascinating coordinated behavior of living organisms or self-propelled particles (SPPs). Particularly, monopolar flocking has been attractive due to its potential applications in various fields. However, the underlying mechanism behind flocking and emergence of monopolar motion in flocking of SPPs has remained obscured. Here, we demonstrate monopolar flocking of kinesin-driven microtubules, a self-propelled biomolecular motor system. Microtubules with an intrinsic structural chirality preferentially move towards counter-clockwise direction. At high density, the CCW motion of microtubules facilitates monopolar flocking and formation of a spiral pattern. The monopolar flocking of microtubules is accounted for by a torque generated when the motion of microtubules was obstructed due to collisions. Our results shed light on flocking and emergence of monopolar motion in flocking of chiral active matters. This work will help regulate the polarity in collective motion of SPPs which in turn will widen their applications in nanotechnology, materials science and engineering.

Solvation effects on diffusion processes of a macromolecule: Accuracy required for radial distribution function to calculate diffusion coefficient.

We investigate the dependence of the diffusion coefficient of a large solute particle on the solvation structure around a solute. The diffusion coefficient of a hard-sphere system is calculated by using a perturbation theory of large-particle diffusion with radial distribution functions around the solute. To obtain the radial distribution function, some integral equation theories are examined, such as the Percus-Yevick (PY), hypernetted-chain (HNC), and modified HNC theories using a bridge function proposed by Kinoshita (MHNC) closures. In one-component solvent systems, the diffusion coefficient depends on the first-minimum value of the radial distribution function. The results of the MHNC closure are in good agreement with those of calculation using the radial distribution functions of Monte Carlo simulations since the MHNC closure very closely reproduces the radial distribution function of Monte Carlo simulations. In binary-solvent mixtures, the diffusion coefficient is affected by the larger solvent density distribution in the short-range part, particularly the height and sharpness of the first peak and the depth of the first minimum. Since the HNC closure gives the first peak that is higher and sharper than that of the MHNC closure, the calculated diffusion coefficient is smaller than the MHNC closure result. In contrast, the results of the PY closure are qualitatively and quantitatively different from those of the MHNC and HNC closures.

Solvent effect for an effective attraction between like-charged macroions immersed in an electrolyte solution: The intensification mechanism of the effective attraction caused by the translational motion of solvent particles.

The effective interaction between macroanions immersed in an electrolyte solution was calculated using an integral equation theory of liquids to study the solvent granularity effect on the effective attraction mediated by cations. Explicit and implicit solvent models were examined. The effective attraction for the explicit solvent model was found to be stronger than that for the implicit solvent model. This solvent effect was remarkably enhanced only when the effective attraction between macroanions was strong; this means that the solvent effect is not a usual excluded volume effect. The intensification mechanism of the attraction by the solvent granularity is analyzed in the present study, and an indirect mechanism is proposed.

Pd-catalyzed synthesis of 1-(hetero)aryl-2,2,2-trichloroethanols using chloral hydrate and (hetero)arylboroxines.

1-(Hetero)aryl-2,2,2-trichloroethanols are useful key intermediates for the synthesis of various bioactive compounds. Herein, we describe N-heterocyclic carbene (NHC)-coordinated cyclometallated palladium complex (CYP)-catalyzed (hetero)aryl addition of chloral hydrate using (hetero)arylboroxines, providing a new approach to 1-(hetero)aryl-2,2,2-trichloroethanols. Notably, PhS-IPent-CYP which coordinated the bulky yet flexible 2,6-di(pentan-3-yl)aniline (IPent)-based NHC showed good catalytic activities and promoted the transformation in 24-97% yields.

Robust Reflectance Estimation for Projection-Based Appearance Control in a Dynamic Light Environment.

We present a novel method that robustly estimates the reflectance, even in an environment with dynamically changing light. To control the appearance of an object by using a projector-camera system, an appropriate estimate of the object's reflectance is vital to the creation of an appropriate projection image. Most conventional estimation methods assume static light conditions; however, in practice, the appearance is affected by both the reflectance and environmental light. In an environment with dynamically changing light, conventional reflectance estimation methods require calibration every time the conditions change. In contrast, our method requires no additional calibration because it simultaneously estimates both the reflectance and environmental light. Our method is based on the concept of creating two different light conditions by switching the projection at a rate higher than that perceived by the human eye and captures the images of a target object separately under each condition. The reflectance and environmental light are then simultaneously estimated by using the pair of images acquired under these two conditions. We implemented a projector-camera system that switches the projection on and off at 120 Hz. Experiments confirm the robustness of our method when changing the environmental light. Further, our method can robustly estimate the reflectance under practical indoor lighting conditions.

Carotid artery stenting before surgery for carotid artery occlusion associated with acute type A aortic dissection: Two case reports.

BACKGROUND: We experienced two cases of ischemic stroke resulting from carotid artery occlusion associated with acute type A aortic dissection (ATAAD), in which carotid artery stenting before the surgery for ATAAD resulted in good clinical outcomes.Case 1 description: A 63-year-old woman was hospitalized for conscious disturbance, right hemiparesis, and total aphasia. Computed tomography of the head showed no abnormal findings. Computed tomography angiography showed ATAAD and bilateral common carotid artery occlusion. Surgery was not indicated for ATAAD because of a poor prognosis of ischemic stroke. However, carotid artery stenting of the left common carotid artery occlusion was successfully performed, and her neurological findings improved. The patient underwent hemiarch replacement for ATAAD on the day after carotid artery stenting. Her final modified Rankin Scale was 1. Case 2 Description: A 57-year-old woman was hospitalized for mild left hemiparesis. Magnetic resonance imaging showed right watershed infarction and right common carotid artery occlusion. Computed tomography angiography showed ATAAD. After hospitalization, conscious disturbance appeared and left hemiparesis worsened. Ischemic stroke indicated a poor prognosis for revascularization by surgery for ATAAD. Thus, carotid artery stenting of the right common carotid artery occlusion was performed. The patient's neurological findings improved and she underwent hemiarch replacement for ATAAD at 19 days after carotid artery stenting. Her final modified Rankin Scale was 1. CONCLUSIONS: In the present cases, although ischemic stroke was serious and precluded surgical indication for ATAAD, carotid artery stenting before surgery for ATAAD resulted in good clinical outcomes. Performing carotid artery stenting before surgery for ATAAD is challenging but achievable, and is a valid treatment option depending on the individual cases.