The usefulness of texture and color enhancement imaging to identify the minor papilla orifice.

In clinical cases of pancreas divisum, endoscopic retrograde cholangiopancreatography often necessitates cannulation of the pancreatic duct through the minor papilla. Nevertheless, this procedure can be challenging because of the small size of the minor papilla and the difficulty in visualizing the ductal orifice. A new image-enhanced endoscopy technique called texture and color enhancement imaging (TXI) has been developed, which enhances texture, brightness, and color compared with white-light imaging, resulting in subtle differences in the surface mucosa. Herein, we describe the case of a 73-year-old man with pancreas divisum in whom TXI was useful in identifying the orifice of the minor papilla. He was referred to our hospital with repetitive acute exacerbation of chronic pancreatitis. Since contrast-enhanced computed tomography revealed a pancreatic stone in the main pancreatic duct, endoscopic retrograde cholangoepancreatography was performed as a therapeutic intervention. Despite the initial difficulty in identifying the orifice of the minor papilla on white-light imaging, TXI enhanced its visibility successfully, enabling dorsal pancreatic duct cannulation via the minor papilla. Subsequently, endoscopic pancreatic sphincterotomy was performed and a 6Fr plastic stent was placed. Post-endoscopic therapy, the patient's abdominal pain was relieved. TXI was useful in identifying the minor papilla orifice and led to successful cannulation.

Comparison of metabolic parameters between oral and total parenteral nutrition in children with severe eating disorders.

BACKGROUND: This study investigated changes of lipid parameters in children with severe eating disorders during refeeding in order to explore the optimal timing for lipid preparation administration. METHODS: We prospectively assessed the physical conditions of patients with eating disorders after the start of nutrition therapy. The assessments were performed at admission and at 2 and 4 weeks. Lipid metabolism was assessed based on triglyceride (TG), total cholesterol (TC), and free carnitine (FC) levels, as well as acylcarnitine/free carnitine (AC/FC) ratio. RESULTS: A total of 18 patients were included. Of these, 12 and 6 received an oral diet (OD group) and total parenteral nutrition (TPN group), respectively. The mean body mass indexes at hospital admission were 12.8 kg/m2 in the OD group and 12.7 kg/m2 in the TPN group. At 2 weeks after the start of refeeding, TC, TG, and AC/FC levels were significantly lower in the TPN group than in the OD group. Other blood test results did not show any significant differences between the two groups. CONCLUSIONS: Fat-free glucose-based nutrition promoted lipid metabolism over a 2-week period after the start of refeeding, suggesting that balanced energy and lipid intake are essential, even in TPN.

Comparison of metabolic parameters between oral and total parenteral nutrition in children with severe eating disorders.

BACKGROUND: This study investigated changes of lipid parameters in children with severe eating disorders during refeeding in order to explore the optimal timing for lipid preparation administration. METHODS: We prospectively assessed the physical conditions of patients with eating disorders after the start of nutrition therapy. The assessments were performed at admission and at 2 and 4 weeks. Lipid metabolism was assessed based on triglyceride (TG), total cholesterol (TC), and free carnitine (FC) levels, as well as acylcarnitine/free carnitine (AC/FC) ratio. RESULTS: A total of 18 patients were included. Of these, 12 and 6 received an oral diet (OD group) and total parenteral nutrition (TPN group), respectively. The mean body mass indexes at hospital admission were 12.8 kg/m2 in the OD group and 12.7 kg/m2 in the TPN group. At 2 weeks after the start of refeeding, TC, TG, and AC/FC levels were significantly lower in the TPN group than in the OD group. Other blood test results did not show any significant differences between the two groups. CONCLUSIONS: Fat-free glucose-based nutrition promoted lipid metabolism over a 2-week period after the start of refeeding, suggesting that balanced energy and lipid intake are essential, even in TPN.

Safety and feasibility of a novel total percutaneous post-closure technique after bedside Impella decannulation in patients with cardiogenic shock.

OBJECTIVES: The Impella (Abiomed) is a widely used percutaneous mechanical circulatory support device for high-risk percutaneous coronary intervention in patients with cardiogenic shock. This study aimed to determine the safety and feasibility of a non-angio-guided post-closure approach using the Perclose ProGlide (Abbott) to decannulate the Impella in the intensive care unit. METHODS: This retrospective study included consecutive patients who were successfully weaned from mechanical circulatory support using the Impella device between April 2019 and April 2022 at Hamamatsu University School of Medicine. Fifteen patients underwent complete post-closure of the femoral artery access sites at the bedside. Technical success of the post-closure hemostasis technique was defined as no evidence of bleeding or additional medical procedures after manual compression. The safety endpoints comprised the Valve Academic Research Consortium-3 and Bleeding Academic Research Consortium criteria. RESULTS: All patients achieved successful hemostasis with this novel technique without surgical conversion. There was no significant bleeding; however, procedure-related vessel occlusion was observed in 1 patient who was recanalized with balloon angioplasty. CONCLUSIONS: Bedside post-closure using the Perclose ProGlide device is a safe and feasible alternative to manual compression and surgical removal of the Impella device with low bleeding or vascular complications rates.

High-angular resolution diffusion imaging generation using 3d u-net.

PURPOSE: To investigate the effects on tractography of artificial intelligence-based prediction of motion-probing gradients (MPGs) in diffusion-weighted imaging (DWI). METHODS: The 251 participants in this study were patients with brain tumors or epileptic seizures who underwent MRI to depict tractography. DWI was performed with 64 MPG directions and b = 0 s/mm2 images. The dataset was divided into a training set of 191 (mean age 45.7 [± 19.1] years), a validation set of 30 (mean age 41.6 [± 19.1] years), and a test set of 30 (mean age 49.6 [± 18.3] years) patients. Supervised training of a convolutional neural network was performed using b = 0 images and the first 32 axes of MPG images as the input data and the second 32 axes as the reference data. The trained model was applied to the test data, and tractography was performed using (a) input data only; (b) input plus prediction data; and (c) b = 0 images and the 64 MPG data (as a reference). RESULTS: In Q-ball imaging tractography, the average dice similarity coefficient (DSC) of the input plus prediction data was 0.715 (± 0.064), which was significantly higher than that of the input data alone (0.697 [± 0.070]) (p < 0.05). In generalized q-sampling imaging tractography, the average DSC of the input plus prediction data was 0.769 (± 0.091), which was also significantly higher than that of the input data alone (0.738 [± 0.118]) (p < 0.01). CONCLUSION: Diffusion tractography is improved by adding predicted MPG images generated by an artificial intelligence model.

Association of Malnutrition and High Bleeding Risk with Long-Term Prognosis in Patients with Acute Coronary Syndrome following Percutaneous Coronary Intervention.

BACKGROUND: Malnutrition in cardiovascular disease is associated with poor prognosis, especially in patients with heart failure and acute coronary syndrome (ACS). High bleeding risk is also linked to coronary artery disease prognosis, including ACS. However, whether the extent of malnutrition and high bleeding risk have a cumulative impact on the long-term prognosis of patients with ACS who undergo percutaneous coronary intervention remains unclear. METHODS: We analyzed 275 patients with ACS treated with percutaneous coronary intervention. The Controlling Nutritional Status score and Japanese version of the Academic Research Consortium for High Bleeding Risk criteria (J-HBR) were retrospectively evaluated. The primary and secondary outcomes were adjusted using the inverse probability treatment weighting method. RESULTS: The prevalence of moderate or severe malnutrition in this cohort was 16%. Kaplan-Meier analysis showed a significantly higher incidence of major adverse cardiovascular and cerebrovascular events in patients who were moderately or severely malnourished than in those who were not. Notably, the incidence of these major events was similar between severely malnourished patients with J-HBR and those without. CONCLUSION: Moderate or severe malnutrition has a significant impact on the long-term prognosis of patients with ACS who undergo percutaneous coronary intervention.

Atomistic Chemical Elucidation of the Higher-Rate Reaction Mechanism in Hf-Pyridyl Amido-Catalyzed Copolymerization of Ethene and 1-Octene: Application of Red Moon Simulation with Polymer Propagation Diagrams.

The Hf-pyridyl amido complex ((pyridylamido)Hf(IV)) is a cationic catalyst activated by ion-pairing with auxiliary catalyst B(C6F5)4 to show high activity for α-olefin polymerization. Previously, it was experimentally observed that the consumption rate of 1-octene in the 1-octene/ethene copolymerization is 3-fold compared to the 1-octene homopolymerization in coordinative chain transfer polymerization using the catalyst HfCat+-B(C6F5)4- ion pair (IP) and the chain transfer agent (CTA) ZnEt2. In the present study, we have performed atomistic chemical simulations of the IP-catalyzed homopolymerization of 1-octene and copolymerization of 1-octene and ethene on the basis of the Red Moon (RM) methodology. Using the analysis by polymer propagation diagrams (PPDs), in the 1-octene homopolymerization and the 1-octene/ethene copolymerization with the 1-octene-inserted catalyst (oHfCat), it is theoretically shown that the propagation reactions intermittently pause due to the steric hindrance of two hexyl groups of the oHfCat and the 1-octene inserted adjacent to the Hf atom. On the other hand, in the polymerizations with the ethene-inserted catalyst (eHfCat), it is reasonably recognized that the propagation reactions occur smoothly at a constant rate, and the polymerization continuously proceeds due to the relatively smaller steric hindrance. In conclusion, it was shown, for the first time, that the RM method can be used to reveal the microscopic effects of monomers and substituents in the polymerization reaction processes. Therefore, our current work using PPDs demonstrates the promising potential of the RM methodology in studying catalytic olefin polymerizations and complex chemical reaction systems in general.

Prospective Study of Vonoprazan-Based First-Line Triple Therapy with Amoxicillin and Metronidazole for Clarithromycin-Resistant Helicobacter pylori.

AIM: This was a prospective, multicenter, single-arm intervention, against historical controls, study of the efficacy of a vonoprazan-based 7-day triple regimen with metronidazole (VPZ-AMPC-MNZ) as a first-line therapy for eradicating clarithromycin-resistant Helicobacter pylori (H. pylori). METHODS: We enrolled 35 patients positive for clarithromycin-resistant H. pylori, as assessed by culture, without a history of eradication. These 35 patients were prospectively eradicated with VPZ-AMPC-MNZ. As historical controls, we also assessed 98 patients with clarithromycin-resistant H. pylori from our prior prospective studies, who achieved H. pylori eradication with a 7-day triple regimen including clarithromycin (VPZ-AMPC-CAM). A preplanned analysis was performed as a superiority study against the historical controls (VPZ-AMPC-MNZ compared to VPZ-AMPC-CAM). In each regimen, vonoprazan was used at 20 mg bid, amoxicillin at 750 mg bid, metronidazole at 250 mg bid, and clarithromycin at 200 mg or 400 mg bid for 7 days. We assessed the outcome of eradication therapy using a 13C-urea breath test or H. pylori stool antigen test. We evaluated safety using patient questionnaires. RESULTS: The intention-to-treat (ITT) and per-protocol (PP) eradication rates of VPZ-AMPC-MNZ were both 100% (95% confidence interval (95% CI) 90.0-100%, n = 35). The eradication rates of VPZ-AMPC-CAM were 76.5% (95% CI 66.9-84.5%, n = 98) in the ITT analysis and 77.3% (95% CI 67.7-85.2%, n = 97) in the PP analysis. The eradication rate of VPZ-AMPC-MNZ was significantly higher than that of VPZ-AMPC-CAM in both the ITT (p = 0.00052) and PP (p = 0.00095) analyses. CONCLUSIONS: The findings suggest that 7-day VPZ-AMPC-MNZ was superior to 7-day VPZ-AMPC-CAM as a first-line regimen for eradicating clarithromycin-resistant H. pylori. We suggest VPZ-AMPC-MNZ as the standard first-line regimen for eradication of clarithromycin-resistant H. pylori in Japan.

Native T1 mapping in early diffuse and limited systemic sclerosis, and its association with diastolic function.

BACKGROUND: Systemic sclerosis (SSc) is divided into diffuse and limited cutaneous SSc (dcSSc and lcSSc). The dcSSc subtype has more severe internal organ damage. This study aimed to assess whether cardiovascular magnetic resonance (CMR) parametric mapping could detect early cardiac involvement and evaluate differences between these two subtypes. METHODS: Eighty SSc patients (37 dcSSc and 43 lcSSc) underwent CMR at 3.0 T (Philips Healthcare, Best, The Netherlands) in our hospital between July 2018 and July 2021. We analyzed myocardial damage by CMR parametric mapping and compared it with clinical data. RESULTS: The median duration of the disease was 10.2 months. The left ventricular ejection fraction was preserved in both groups. DcSSc had significantly higher native T1 (1333.4 ±â€¯71.2 ms vs. 1295.0 ±â€¯42.7 ms, p = 0.006) and extracellular volume fraction (32.6 ±â€¯4.1 % vs. 30.3 ±â€¯4.0 %, p = 0.018) in the mid-ventricular septum as compared to lcSSc, although there were no differences in T2 values. Native T1 values were positively correlated with the E/e' ratio and left atrial volume indices evaluated by transthoracic echocardiography in overall SSc and dcSSc, but not in lcSSc. Logistic regression analysis revealed that native T1 was an independent predictor of left ventricular diastolic dysfunction in SSc patients (odds ratio, 1.194; 95 % confidence interval, 1.021-1.396; p = 0.026). Native T1 was higher in SSc patients with progressive skin lesions. Additionally, there were positive correlations between brain natriuretic peptide, New York Heart Association functional classification, and native T1. CONCLUSIONS: CMR parametric mapping is a useful tool for detecting myocardial changes. Native T1 was the most sensitive parameter for identifying diffuse myocardial changes in the early stages of SSc and was associated with left ventricular diastolic function. DcSSc had more severe myocardial involvement than lcSSc; therefore, the use of CMR parametric mapping may aid in its prediction.

Age-Dependent Hemorrhage Risk and Obliteration Benefit After Radiosurgery for Brain Arteriovenous Malformation.

PURPOSE: Because patients with untreated brain arteriovenous malformations (BAVMs) are at variable risks of cerebral hemorrhage and associated mortality and morbidity, it is essential to identify patient populations who benefit most from prophylactic interventions. This study aimed to examine age-dependent differences in the therapeutic effect of stereotactic radiosurgery (SRS) on BAVMs. METHODS AND MATERIALS: This retrospective observational study enrolled patients with BAVMs who underwent SRS at our institution between 1990 and 2017. The primary outcome was post-SRS hemorrhage, and the secondary outcomes included nidus obliteration, post-SRS early signal changes, and mortality. To investigate age-related differences in outcomes after SRS, we performed age-stratified analyses using the Kaplan-Meier analysis and weighted logistic regression with the inverse probability of censoring weighting (IPCW). To address significant differences in patient baseline characteristics, we also performed inverse probability of treatment weighting (IPTW) adjusted for possible confounders to investigate age-related differences in outcomes after SRS. RESULTS: A total of 735 patients with 738 BAVMs were stratified by age. Age-stratified analysis using a weighted logistic regression model with IPCW showed a direct correlation between patient age and post-SRS hemorrhage (odds ratio [OR], 95% confidence interval [CI], and P value: 2.20, 1.34-3.63, and .002 at 18 months; 1.86, 1.17-2.93, and .008 at 36 months; and 1.61, 1.05-2.48, and .030 at 54 months, respectively). The age-stratified analysis also showed an inverse relationship between age and obliteration over the first 42 months after SRS (OR, 95% CI, and P value: 0.05, 0.02-0.12, and <.001 at 6 months; 0.55, 0.44-0.70, and <.001 at 24 months; and 0.76, 0.63-0.91, and .002 at 42 months, respectively). These results were also confirmed with the IPTW analyses. CONCLUSIONS: Our analysis demonstrated that patients' age at SRS is significantly associated with hemorrhage and the nidus obliteration rate after treatment. In particular, younger patients are more likely to exhibit reduced cerebral hemorrhages and achieve earlier nidus obliteration compared with older patients.

Improving detection performance of hepatocellular carcinoma and interobserver agreement for liver imaging reporting and data system on CT using deep learning reconstruction.

PURPOSE: This study aimed to compare the hepatocellular carcinoma (HCC) detection performance, interobserver agreement for Liver Imaging Reporting and Data System (LI-RADS) categories, and image quality between deep learning reconstruction (DLR) and conventional hybrid iterative reconstruction (Hybrid IR) in CT. METHODS: This retrospective study included patients who underwent abdominal dynamic contrast-enhanced CT between October 2021 and March 2022. Arterial, portal, and delayed phase images were reconstructed using DLR and Hybrid IR. Two blinded readers independently read the image sets with detecting HCCs, scoring LI-RADS, and evaluating image quality. RESULTS: A total of 26 patients with HCC (mean age, 73 years ± 12.3) and 23 patients without HCC (mean age, 66 years ± 14.7) were included. The figures of merit (FOM) for the jackknife alternative free-response receiver operating characteristic analysis in detecting HCC averaged for the readers were 0.925 (reader 1, 0.937; reader 2, 0.913) in DLR and 0.878 (reader 1, 0.904; reader 2, 0.851) in Hybrid IR, and the FOM in DLR were significantly higher than that in Hybrid IR (p = 0.038). The interobserver agreement (Cohen's weighted kappa statistics) for LI-RADS categories was moderate for DLR (0.595; 95% CI, 0.585-0.605) and significantly superior to Hybrid IR (0.568; 95% CI, 0.553-0.582). According to both readers, DLR was significantly superior to Hybrid IR in terms of image quality (p ≤ 0.021). CONCLUSION: DLR improved HCC detection, interobserver agreement for LI-RADS categories, and image quality in evaluations of HCC compared to Hybrid IR in abdominal dynamic contrast-enhanced CT.

Dependence of apparent diffusion coefficient on slice position in magnetic resonance diffusion imaging.

PURPOSE: The position dependence of the apparent diffusion coefficient (ADC) in magnetic resonance imaging (MRI) by echo-planar imaging (EPI)- and turbo spin echo (TSE)-diffusion-weighted imaging (DWI) was assessed using phantoms. METHODS: Six pure water-filled containers were placed parallel to the direction of the static magnetic field from the center of the magnetic field to the foot direction (five containers) and the head direction (one container). Six slice positions were set, and a cross-section image was scanned at the center of each container using a 1.5-T MRI scanner. Diffusion times for both EPI- and TSE-DWI were matched as much as possible. The slice thickness was adjusted to match the signal-to-noise ratio (SNR) at the center of the magnetic field for both sequences. A B1 map was analyzed. The ADC and SNR at each position of both sequences were tested using the Wilcoxon signed-rank test (P = 0.05) and compared using Friedman and Steel-Dwass multiple comparison tests (P = 0.05). Pearson correlation coefficients between ADC and SNR and between ADC and flip angle (FA) were calculated. RESULTS: ADC decreased significantly with distance from the center of the magnetic field for both EPI-DWI and TSE-DWI (P < 0.05). TSE-ADC was significantly higher than EPI-ADC for all combinations (P < 0.01). Based on the Friedman test, the SNR of EPI- and TSE-DWI was significantly different and depended on the slice position (P < 0.01). The Pearson correlation coefficient between ADC and SNR was 0.78 in EPI-DWI and 0.60 in TSE-DWI, whereas that between ADC and FA was 0.97 in EPI-DWI and 0.94 in TSE-DWI. The FA decreased by 0.048 and 0.047° per mm from the center of the magnetic field to head and foot directions, respectively. CONCLUSION: ADC depends on the slice position and decreases with an increase in distance from the magnetic field center. Caution should be taken when comparing and quantitatively evaluating the ADC at sites shifted in the long-axis direction.

Impact of mindfulness tendency and physical activity on brain-gut interactions.

BACKGROUND: Irritable bowel syndrome (IBS) is a disorder of brain-gut interactions characterized by abdominal pain and bowel dysfunction. Exercise and mindfulness have been reported to be effective on IBS, but there has been no study of their interaction. In this study, we hypothesized that exercise and mindfulness interactively affect the severity of IBS symptoms. METHODS: Subjects were 703 adolescents with 590 women and 113 men. Their IBS status was evaluated with Rome III Diagnostic Questionnaire and IBS Severity Index (IBS-SI). They also fulfilled past exercise experience, athletic performance and exercise enthusiasm, International Physical Activity Questionnaire (IPAQ), Mindful Attention Awareness Scale (MAAS), Kessler 6 Scale (K6), and Perceived Stress Scale (PSS). Statistical analysis was performed using SPSS v25. RESULTS: In this population, 184 (158 women and 26 men, 14.1%) subjects had Rome III IBS symptoms. IBS subjects scored significantly less in exercise enthusiasm at high school (p = 0.017) and MAAS (p < 0.001) and significantly more K6 (p < 0.001) and PSS (p < 0.001) than non-IBS. The two-way ANOVA on IBS-SI showed a significant main effect of MAAS (p < 0.001) and interaction between MAAS and IPAQ (p = 0.008). CONCLUSION: It is suggested that mindfulness per se decreases IBS severity, but that mindfulness and physical activity interactively affect the severity. Further studies on how to design interventional trials for IBS patients with mindfulness and physical exercise are warranted.

(Pyridylamido)Hf(IV)-Catalyzed 1-Octene Polymerization Reaction Interwoven with the Structural Dynamics of the Ion-Pair-Active Species: Bridging from Microscopic Simulation to Chemical Kinetics with the Red Moon Method.

We performed the atomistic simulation of 1-octene polymerization reaction catalyzed by the ionic pair (IP) consisting of the cationic active species of (pyridylamido)Hf(IV) catalyst, HfCatPn+, and different counteranions (CAs), B(C6F5)4- and MeB(C6F5)3-, at different monomer concentrations. Using a hybrid Monte Carlo/molecular dynamics method, that is, the Red Moon (RM) method, the reaction progress measured by the "RM cycle" was transformed into effective real time using the time transformation theory. Then, the degree of polymerization was found to be consistent with that in the chemical kinetics, a macroscopic theory, and experimental ones. Remarkably, the current simulation has revealed the different dynamical features in the polymerization behavior originating from the CA. Namely, the HfCatPn+-B(C6F5)4- IP mainly forms an outer-sphere IP (OSIP) throughout the polymerization. The HfCatPn+-MeB(C6F5)3- IP, on the other hand, forms an inner-sphere IP (ISIP) in the initial stage of polymerization, and the ratio of ISIP steeply drops after the first monomer insertion because the IP interaction is reduced by the steric hindrance between the inserted monomers and the CA. In conclusion, we have shown that the microscopic IP dynamics interwoven with the polymerization reaction can be computationally observed in the real-time domain by using the RM method. Therefore, our current work demonstrates the promising potential of the RM method in studying catalytic olefin polymerization and complex chemical reaction systems.

Rapid MR Angiography Using 3D Gradient-echo Imaging and the Two-point Dixon Method to Evaluate Carotid Plaque.

Liver acquisition with volume acceleration-flex (LAVA-Flex) acquires out-of-phase and in-phase echo images and automatically generates water-only and fat-only images from one single acquisition. The scan time of carotid MR angiography (MRA) using LAVA-Flex (LAVA MRA) is about one-fifth that of conventional time-of-flight MRA (cTOF MRA). We aimed to investigate whether LAVA MRA could provide useful information for the diagnosis of carotid plaque by utilizing the ability to acquire multiple sequences simultaneously. Comparing LAVA MRA and cTOF MRA images for carotid plaque, low-intensity plaques were more clearly identified in the in-phase images, and high-intensity plaques were more clearly identified in the water-only or out-of-phase images. None of the plaques exhibited superior visualization with the cTOF sequence. We concluded that LAVA MRA can provide more useful information on plaque evaluation using multiple sequences than cTOF MRA.

A Japanese patient with neonatal biotin-responsive basal ganglia disease.

Biotin-responsive basal ganglia disease (BBGD) with SLC19A3 mutation was first reported in 1998, and over 30 mutations have been reported. We report a neonatal BBGD case with sudden-onset feeding difficulty and impaired consciousness. Encephalopathy resolved after the initiation of biotin and thiamine treatment. Genetic testing revealed a novel heterozygous mutation [c.384_387del, p.Tyr128fs];[c.265 A > C, p.Ser89Arg] in SLC19A3. Early treatment for BBGD is essential, especially with onset in the neonatal or early infancy period.

Stereotactic Radiosurgery Provides Long-Term Safety for Patients With Arteriovenous Malformations in the Diencephalon and Brainstem: The Optimal Dose Selection and Long-Term Outcomes.

BACKGROUND: Arteriovenous malformations (AVMs) of the diencephalon (DC) and brainstem (BS) are difficult to treat. Stereotactic radiosurgery (SRS) is a reasonable option; however, an optimal radiosurgical dose needs to be established to optimize long-term outcomes. OBJECTIVE: To evaluate dose-dependent long-term outcomes of SRS for DC/BS-AVMs. METHODS: We retrospectively analyzed the long-term outcomes of 118 patients who had SRS-treated DC/BS-AVMs. The outcomes included post-SRS hemorrhage, AVM obliteration, neurological outcomes, and disease-specific survival. According to margin doses, the patients were classified into low (<18 Gy), medium (18-20 Gy), and high (>20 Gy) dose groups. RESULTS: SRS reduced the annual hemorrhage rate from 8.6% to 1.6% before obliteration and 0.0% after obliteration. The cumulative hemorrhage rate in the low dose group was likely to be higher than that in the other groups ( P = .113). The cumulative obliteration rates in the entire cohort were 74% and 83% at 5 and 10 years, respectively, and were significantly lower in the low dose group than in the other groups (vs medium dose: P = .027, vs high dose: P = .016). Multivariate analyses demonstrated that low dose SRS was significantly associated with worse obliteration rates (hazard ratio 0.18, 95% CI 0.04-0.79; P = .023). CONCLUSION: SRS with a margin dose of 18 to 20 Gy for DC/BS-AVMs may be optimal, providing a higher obliteration rate and lower risk of post-SRS hemorrhage than lower dose SRS. Dose reduction to <18 Gy should only be optional when higher doses are intolerable.

Hemodynamic changes during the obliteration process for cerebral arteriovenous malformations after radiosurgery.

OBJECTIVE: The process of cerebral arteriovenous malformation (AVM) obliteration following radiosurgery is poorly understood. Authors of this retrospective study aimed to assess the changes in AVM hemodynamics after stereotactic radiosurgery (SRS) by using 3D flow magnetic resonance imaging (MRI) to elucidate the process of AVM obliteration. METHODS: Twenty-four patients with AVMs treated with SRS between July 2015 and December 2017 were included in this study and classified into two groups depending on the duration of AVM obliteration: group A, obliteration within 3 years (n = 15); and group B, obliteration taking more than 3 years or no obliteration (n = 9). Blood flow (ml/min) in the largest feeding artery was measured before and after SRS by using time-averaged 3D flow MRI. The decreasing rate of blood flow in the feeding artery after SRS was calculated as the percent change from baseline blood flow. A Wilcoxon rank-sum test was used to compare the decreasing blood flow rate between the two groups at 4 and 12 months after SRS. RESULTS: For the entire cohort, the mean decrease in blood flow in the feeding artery from baseline was 29% at 4 months and 71% at 12 months after SRS. In general, blood flow after SRS decreased faster in group A and slower in group B. The decreasing rates in blood flow at 4 and 12 months after SRS were significantly different between the two groups (p = 0.02 and < 0.001, respectively). CONCLUSIONS: Tracking changes in AVM hemodynamics after SRS may be useful for assessing the progress of AVM obliteration and the therapeutic effects of SRS, possibly contributing to the prediction of subsequent obliteration outcome.