Scan Interval Research Articles

NIMG-75. SIMILARITY DISTANCES-BASED DELTA RADIOMICS (SDDR) ENABLES LONGITUDINAL MRI COMPARISONS FOR SURVIVAL PREDICTION IN GLIOMAS: A MULTI-INSTITUTIONAL VALIDATION

Abstract Radiomics (computerized feature analysis) on treatment-naive MRI scans has demonstrated great value in outcome prediction for Glioblastoma (GBM). However, delta radiomics (analysis of radiomic feature variation between different events, e.g., before and after treatment) has not been explored on account of challenges with precise spatial correspondences between pre- and post-operative scans. This work presents a survival prediction model for GBM, Similarity Distances-based delta radiomics (SDDR), based on the hypothesis that similarity distance-measures between radiomic features on pre-, and post-treatment images can accurately capture temporal changes within-and-around the tumor, and provide improved prediction of overall survival, compared to models based on a single timepoint. 150 patients from 2 publicly-available Glioma repositories (University of California San Francisco “UCSF” (n=48), LUMIERE (n=67)) and 2 two proprietary datasets (from xCures (n=13), and Cleveland Clinic (CCF) (n=74)) were obtained. UCSF and LUMIERE cohorts were used as separate hold-out sets, in each of which the remaining collections were used as discovery set. Following pre-processing, tumor segmentation into Edema (ED) and Enhancing tumor (ET) were performed. SDDR was then computed, which is the distance between probability densities functions from 156 gray co-occurrence (GLCM) and 52 gradient-based co-occurrences statistics (COLLAGE) features extracted from pre and-post-treatment MRI. Six statistical distances (e.g., Earth mover distance) normalized by the scanning interval (in weeks) yielded n=2496 SDDR measurements per tumor region (1248/region, 936 delta-GLCM, and 312 delta-COLLAGE). The same set of features were computed from pretreatment MRI (Pre-R) for comparison. Features were fed to LASSO-Cox regression for survival analysis. SDDR for GLCM features extracted from ET outperformed Pre-R, and demonstrated significant differences between high and low risk groups for both hold out tests: UCSF (p=0.0069, HR =2.8, C-index=0.69) and LUMIERE (p=0.0061, HR = 1.9, C-index 0.65). SDDR-based multi-institutional survival analysis demonstrated promise in reliable longitudinal risk-stratification in GBM.

Polygenic Risk Is Associated With Long-Term Coronary Plaque Progression and High-Risk Plaque.

The longitudinal relation between coronary artery disease (CAD) polygenic risk score (PRS) and long-term plaque progression and high-risk plaque (HRP) features is unknown. The goal of this study was to investigate the impact of CAD PRS on long-term coronary plaque progression and HRP. Patients underwent CAD PRS measurement and prospective serial coronary computed tomography angiography (CTA) imaging. Coronary CTA scans were analyzed with a previously validated artificial intelligence-based algorithm (atherosclerosis imaging-quantitative computed tomography imaging). The relationship between CAD PRS and change in percent atheroma volume (PAV), percent noncalcified plaque progression, and HRP prevalence was investigated in linear mixed-effect models adjusted for baseline plaque volume and conventional risk factors. A total of 288 subjects (mean age 58 ± 7 years; 60% male) were included in this study with a median scan interval of 10.2 years. At baseline, patients with a high CAD PRS had a more than 5-fold higher PAV than those with a low CAD PRS (10.4% vs 1.9%; P< 0.001). Per 10 years of follow-up, a 1 SD increase in CAD PRS was associated with a 0.69% increase in PAV progression in the multivariable adjusted model. CAD PRS provided additional discriminatory benefit for above-median noncalcified plaque progression during follow-up when added to a model with conventional risk factors (AUC: 0.73 vs 0.69; P = 0.039). Patients with high CAD PRS had an OR of 2.85 (95%CI: 1.14-7.14; P = 0.026) and 6.16 (95%CI: 2.55-14.91; P< 0.001) for having HRP at baseline and follow-up compared with those with low CAD PRS. Polygenic risk is strongly associated with future long-term plaque progression and HRP in patients suspected of having CAD.

Lipoprotein(a) and Long-Term Plaque Progression, Low-Density Plaque, and Pericoronary Inflammation

Lipoprotein(a) (Lp[a]) is a causal risk factor for cardiovascular disease; however, long-term effects on coronary atherosclerotic plaque phenotype, high-risk plaque formation, and pericoronary adipose tissue inflammation remain unknown. To investigate the association of Lp(a) levels with long-term coronary artery plaque progression, high-risk plaque, and pericoronary adipose tissue inflammation. This single-center prospective cohort study included 299 patients with suspected coronary artery disease (CAD) who underwent per-protocol repeated coronary computed tomography angiography (CCTA) imaging with an interscan interval of 10 years. Thirty-two patients were excluded because of coronary artery bypass grafting, resulting in a study population of 267 patients. Data for this study were collected from October 2008 to October 2022 and analyzed from March 2023 to March 2024. The median scan interval was 10.2 years. Lp(a) was measured at follow-up using an isoform-insensitive assay. CCTA scans were analyzed with a previously validated artificial intelligence-based algorithm (atherosclerosis imaging-quantitative computed tomography). The association between Lp(a) and change in percent plaque volumes was investigated in linear mixed-effects models adjusted for clinical risk factors. Secondary outcomes were presence of low-density plaque and presence of increased pericoronary adipose tissue attenuation at baseline and follow-up CCTA imaging. The 267 included patients had a mean age of 57.1 (SD, 7.3) years and 153 were male (57%). Patients with Lp(a) levels of 125 nmol/L or higher had twice as high percent atheroma volume (6.9% vs 3.0%; P = .01) compared with patients with Lp(a) levels less than 125 nmol/L. Adjusted for other risk factors, every doubling of Lp(a) resulted in an additional 0.32% (95% CI, 0.04-0.60) increment in percent atheroma volume during the 10 years of follow-up. Every doubling of Lp(a) resulted in an odds ratio of 1.23 (95% CI, 1.00-1.51) and 1.21 (95% CI, 1.01-1.45) for the presence of low-density plaque at baseline and follow-up, respectively. Patients with higher Lp(a) levels had increased pericoronary adipose tissue attenuation around both the right coronary artery and left anterior descending at baseline and follow-up. In this long-term prospective serial CCTA imaging study, higher Lp(a) levels were associated with increased progression of coronary plaque burden and increased presence of low-density noncalcified plaque and pericoronary adipose tissue inflammation. These data suggest an impact of elevated Lp(a) levels on coronary atherogenesis of high-risk, inflammatory, rupture-prone plaques over the long term.

The Role of CT Perfusion in Differentiating Benign Versus Malignant Focal Pulmonary Lesions.

Contrast-enhanced CT scan is the standard imaging for the characterization and evaluation of focal parenchymal lung lesions. It relies on morphology and enhancement patterns for the characterization of lung lesions. However, there is significant overlap among imaging features of various malignant and benign lesions. Hence, it is often necessary to obtain tissue diagnosis with invasive percutaneous or endoscopic-guided tissue sampling. It is often desirable to have non-invasive techniques that can differentiate malignant and benign lung lesions. CT perfusion is an emerging CT technology that allows functional assessment of tissue vascularity through various parameters and can help in differentiating benign and malignant focal lung lesions. The purpose of this study was to assess the role of the CT perfusion technique in differentiating malignant and benign focal parenchymal lung lesions. In this prospective observational study, CT perfusion was performed on 41 patients with focal parenchymal lung lesions from December 2020 to June 2022. The four-dimensional range was planned to cover the entire craniocaudal extent of the lesion, followed by a volume perfusion CT (VPCT) of the lesion. A total of 27 dynamic datasets were acquired with a scan interval of 1.5 seconds and a total scan time of 42 seconds. CT perfusion parameters of blood flow (BF), blood volume (BV), and k-trans of the lesionwere measured withmathematical algorithms available in the Syngo.via CT perfusion software (Siemens Healthcare, Erlangen, Germany). The median BV in benign lesions was found to be 5.5 mL/100 g, with an interquartile range of 3.3-6.9 and a p-value < 0.001. The median BV in malignant lesions was found to be 11.35 mL/100 g, with an interquartile range of 9.57-13.21 and a p-value ≤ 0.001. The median BF for benign lesions was 45.5 mL/100 g/min, with an interquartile range of 33.8-48.5and a p-value ≤ 0.001. The median BF for malignant lesion was 61.77 mL/100 g/min, with an interquartile range of 33.8-48.5and a p-value ≤ 0.001. The median k-trans in the case of benign lesions was found to be 4.2 mL/100 g/min, with an interquartile range of 3.13-6.8 and a p-value ≤ 0.001. The median k-trans in the case of the malignant lesion was found to be 12.05 mL/100g/min, with an interquartile range of 7.20-33.42 and a p-value < 0.001. Our study has also shown BV to have an accuracy of 92.68%, sensitivity of 93.3%, and specificity of 90.01%. Our study has shown that CT perfusion values of BV, BF, and k-trans can be used to differentiate between benign and malignant focal lung parenchymal lesions. K-trans is the most sensitive parameter while BV and BF have greater accuracy and specificity.

Superhydrophobic performance of aluminum textured with a picosecond laser

Aluminum is a common and light engineering metal with high strength, good processability, corrosion resistance, high electrical conductivity, and strong recyclability, properties that allow its wide use in different fields. Strengthening the surface properties of aluminum materials can not only enable aluminum materials to be applied to complex environments but also extend their service life. In this study, two kinds of micro–nano structures—unidirectional micro-grooves and grid micro-grooves—were prepared on the surface of 1060 aluminum using picosecond-laser direct etching, so that its surface can attain superhydrophobic properties and enhance its application performance. The effect of the scanning interval of picosecond laser on the hydrophobic performance was investigated, and the findings indicate that the hydrophobic properties are most effective by using scanning interval of 20 μm. The scanning electron microscope (SEM) and atomic force microscope (AFM) analyses revealed the formation of a micro-nano structure resembling nanoflower particles on the laser-treated aluminum surface, which contributed to increased surface roughness. EDS analysis indicated an increase in carbon (C) content, likely due to the adsorption of organic molecules from the air, which further promoted hydrophobicity. X-ray diffraction spectrometry (XRD) and X-ray photoelectron spectroscopy (XPS) provided insights into the surface chemistry and the presence of various elements and compounds. The superhydrophobic aluminum surfaces demonstrated remarkable stability and self-cleaning capabilities, desirable traits for many practical applications. This study provides a simple and rapid method for preparing superhydrophobic materials on aluminum surfaces and has potential practical application value.This innovation paves the way for the development of high-performance aluminum materials suitable for a wide range of environments and uses.

Refining Surveillance Guidelines after Stereotactic Body Radiation Therapy for Early-Stage Lung Cancer

IntroductionStereotactic body radiation therapy (SBRT) is a treatment for patients with early-stage non-small cell lung cancer (ES-NSCLC). Surveillance guidelines vary after treatment. While patients are more likely to locally recur within 2 years of treatment, there remains a paucity of data on the benefit of frequent and long-term surveillance. We evaluated a cohort of NSCLC patients to evaluate surveillance patterns and outcomes. Materials and methodsPatients with ES-NSCLC treated with SBRT were retrospectively evaluated. Imaging was reviewed after SBRT for evidence of recurrence or new malignancy. The median scan interval (MSI) was calculated as the median number of months between surveillance scans. The MSI between patients with or without new disease was compared by t-test. New disease development and survival between patients with <T2 or >=T2 disease and with or without prior malignancy was compared using χ², Kaplan-Meier analysis, and Gray's test. ResultsA cohort of 168 patients with median follow up of 23.4 months met criteria for review with 50% developing new disease. MSI did not differ between patients with or without new disease. Patients with >=cT2 tumors had worse overall survival and trended towards higher incidence of new disease. New disease continued to occur, even 5 years after treatment. ConclusionIncreased scan frequency did not increase detection of new disease. Patients continued to fail 5 years after treatment. Larger tumors trended toward more frequent failures and those patients experienced worse OS. Surveillance guidelines should be optimized to prevent over surveillance after treatment and to continue long-term surveillance.

Spatial distortions in swept source optical coherence tomography due to lateral scanning.

The paper presents errors in axial distance measurements and deviations of contours in swept source (SS) optical coherence tomography (OCT) cross sections due to lateral scanning. The study shows how these errors and deviations depend on the adjustments of the interface optics between a lateral scanner device and the target imaged. A theoretical model and experiments demonstrate that these errors and deviations are given by the Doppler shift frequency imprinted by the lateral scanning. The smaller the number of sweeps per lateral scanning interval, the larger these errors and deviations. The study also shows that the sign of error and deviation of contours can be put in correspondence with the spectral sweeping direction. Even more, it is shown that such effects can be used to predict the tuning direction of the swept source without an optical spectrum analyzer.

LDCT lung cancer screening implementation in a Veterans Affairs hospital: A quality initiative.

e23238 Background: Lung cancer is the number one cause of cancer related deaths worldwide. United States Preventive Services Task Force (USPSTF) recommends annual Lung Cancer Screening (LCS) with Low Dose Computerized Tomography (LDCT) for adults who are current smokers aged 50 to 80 years with at least 20 pack year smoking history or have quit smoking within the past 15 years. Although LCS is a national initiative for Veteran Affairs (VA) Hospitals, there are several barriers in practice. Methods: The LCS program was established with a dedicated coordinator to provide better access to high-quality in-house screening, while reducing the dependance on expensive community care services and referrals. Smoking history in Tobacco Pack Years (TPY) is updated during a Primary Care Physician (PCP) visit, which triggers a clinical reminder in the electronic medical record for LCS. The LCS coordinator would then receive a consult. After shared decision-making with the patient, physician and coordinator, the patients are scheduled for LDCT. If the results are Lung-RADS 1 (negative), 2 or 3 (benign appearing nodules) the patients are notified of the findings and provided with subsequent follow ups. All Lung RADS 4 (suspicious findings) are discussed in the lung tumor board, which includes radiologist, oncologist, pulmonologist, pathologist, cardio-thoracic surgeon, and fellows in training. The committee determines the follow-up scan interval and/or additional investigations. Results: The performance of our LCS Program from June 2022 to January 2024 was reviewed. 5941 patients were assessed for TPY, of those 1127 patients were eligible for LCS scans and 1032 (93.3%) were enrolled into the LCS Program. 951 LDCT scans have been conducted thus far, this includes 598 annual initial screenings, the remaining are follow ups. 57 patients (6.81%) had Lung-RADS 3 findings and are undergoing nodule tracking. 16 patients (1.91%) required diagnostic work-up which includes a PET scan or biopsy. 14 patients (1.67%) have been diagnosed with cancer. Conclusions: Our LDCT Program showed a high acceptance rate of 93.3%, much of which can be attributed to the multiple layers of screening and shared decision-making processes. Patients received three phone calls and a letter as a reminder of their LDCT appointments. Our radiology department has four dedicated slots for LDCT screening each day which allows for further compliance. TPY documentation was identified as a limiting factor in this process. The LCS coordinator verified the TPY history with the patients which helped overcome this shortcoming. Overall a multidisciplinary team approach contributed to the success of our program.

False-positive Findings of Large Vessel Vasculitis on FDG-PET in Patients Treated With Immune Checkpoint Inhibitors.

Fluorine-18 fluorodeoxygluocose positron emission tomography (FDG-PET) is increasingly used in the evaluation of response to immune checkpoint inhibitor (ICI) therapy. Incidental findings of increased vessel wall uptake may prompt the concern for ICI-induced large vessel vasculitis (LVV). Precise radiographic and clinical evaluation is required to determine if this represents true vasculitis, as use of immune suppression and ICI discontinuation can have significant impacts on patient outcomes. We performed a retrospective case analysis of 4 consecutive patients referred to 2 rheumatology clinics treated with ICI with incidental findings of LVV on FDG-PET, reviewing their clinical course and radiographic findings. All 4 cases had FDG-PET scans for routine oncology indications and had no associated clinical features of LVV. One patient was treated with corticosteroids and no patients developed any clinical evidence of vasculitis during a mean follow-up period of 17 months (range: 7-33mo). All FDG-PET images reporting LVV underwent a standardized analysis to identify any technical issues or concerns with interpretation. In review of imaging, 3 of the cases may have been due to delayed tracer to scan interval leading to misinterpretation of vascular uptake as suspected LVV. Recognition of technical pitfalls in FDG-PET interpretation is crucial to inform the need for immunosuppression and the safety of continued ICI therapy.

Longitudinal assessment of syringomyelia in Pomeranians.

Chiari-like malformation (CM) and syringomyelia (SM) are disorders that, in dogs, affect mainly small and toy breeds, including the Pomeranian. These disorders are linked to a great number of (owner-reported) clinical signs (ORCS) suggestive of pain. Aging was associated with an increased risk of having SM in several studies. However, there are only a few longitudinal studies that assess the presence and severity of CM/SM over time in CKCS dogs and progression of SM was linked to progression of clinical signs. The aim of this study was to investigate ORCS, CM/SM classification, and quantitative syrinx parameters in relation to progression of time (age) within individual Pomeranians. Pomeranians with or without ORCS and with or without diagnoses of CM/SM were included that had undergone two (or more) MRI studies of the craniocervicothoracic region between January 2020 and June 2023. Classification of CM/SM and quantitative syrinx measurements were performed. Absolute values as well as ratios for syrinx height, width, and cross-sectional area were included for analysis. A total of 19 Pomeranians were included in the study, of which 11 were male (58%) and 8 were female (42%). The median age at the time of MRI1 was 26 months (range 7-44 months). The median scan interval was 26 months (range 11-49 months). Eleven dogs (58%) were presented with ORCS at the time of MRI1, whereas the other 8 dogs (42%) had no ORCS at that time. At the time of MRI2, there were 17/19 dogs (89%) with ORCS and 2/19 dogs without ORCS (11%). Dogs were significantly more likely to have ORCS at MRI2 than MRI1 (p = 0. 0411). There was no significant difference between CM/SM classification at the time of MRI1 and MRI2. Significant differences were found between MRI1 and MRI2 for syrinx height (based on transverse images) (absolute value and ratio P = 0.0059), syrinx width (absolute value P = 0.1055, ratio P = 0.0039), and syrinx cross sectional area (absolute value P = 0.0195, ratio P = 0.0217). There are differences in the presence or absence of ORCS as well as quantitative syrinx measurements in Pomeranians at different ages. This finding supports that longitudinal changes occur in the SM status of Pomeranians.

Simultaneous reconstruction of 3D fluorescence distribution and object surface using structured light illumination and dual-camera detection

Fluorescence molecular tomography (FMT) serves as a noninvasive modality for visualizing volumetric fluorescence distribution within biological tissues, thereby proving to be an invaluable imaging tool for preclinical animal studies. The conventional FMT relies upon a point-by-point raster scan strategy, enhancing the dataset for subsequent reconstruction but concurrently elongating the data acquisition process. The resultant diminished temporal resolution has persistently posed a bottleneck, constraining its utility in dynamic imaging studies. We introduce a novel system capable of simultaneous FMT and surface extraction, which is attributed to the implementation of a rapid line scanning approach and dual-camera detection. The system performance was characterized through phantom experiments, while the influence of scanning line density on reconstruction outcomes has been systematically investigated via both simulation and experiments. In a proof-of-concept study, our approach successfully captures a moving fluorescence bolus in three dimensions with an elevated frame rate of approximately 2.5 seconds per frame, employing an optimized scan interval of 5 mm. The notable enhancement in the spatio-temporal resolution of FMT holds the potential to broaden its applications in dynamic imaging tasks, such as surgical navigation.

Research on improving the structural stability of surimi 3D printing through laser cooking techniques

At present, research on 3D printing technology for meat protein food is still in its early stages, and improving the molding stability and accuracy of products has always been a key challenge. Here, we take surimi protein as an example and achieve its localized thermal gelation quickly and precisely by incorporating laser sintering technology. And based on the thermal denaturation and solidification of proteins during the printing process, the structural instability problem of meat protein food 3D printing is solved. In this study, we used a CO2 laser with a power of 50 W to locally heat cure surimi during the printing process. The results show that under the conditions of 1 mm laser spot diameter, 500 mm/s scanning speed and 0.25 mm scanning interval, the shape accuracy and gel strength of surimi products with 1.5 mm layer thickness are significantly improved, and this combination parameter shows the best effect in the experiment. This study provides a theoretical basis and reference for real-time solidification in meat protein food printing.

A Proposal for Enhancing Technosignature Search toward the Galactic Center

We discuss the possibility of enhancing intelligent life searches toward the Galactic center. From the clockwork orbital motions of stars around the Sgr A* black hole, we can determine the distance to the Galactic center at an exceptional accuracy, despite its remoteness ∼8.3 kpc. In addition, we can define precise reference epochs by selecting a prominent object such as the bright B-type star S2. These properties have a particular affinity for the coordinated signaling scheme that was hypothesized by Seto for systematically connecting intentional senders to searchers without a prior communication. If S2 is actually being used as a common reference clock, we can compress the search directions around the Galactic center by more than 2 orders of magnitude, with the scanning interval of ∼16 yr.

A methodological approach to compare continuous and instantaneous sampling and two methods to deal with animals out of sight on dairy cattle behavior and interaction with their calf in the first hours post-partum.

Animal behavior can provide useful information about animal welfare, but methods and tools used to gather behavioral data and data treatment can influence the results. Therefore, this study was carried out on dairy cow (Bos taurus) behavior and interaction with calves early post-partum aiming at comparing two sampling rules, namely continuous and instantaneous sampling at scan intervals of 30 s, 1, 2, 3, 4, 5, and 10 min, and of two methods to deal with out of sight animals. The study was based on three assumptions: (1) continuous sampling provides the most complete and accurate data, allowing the observation of seldom behaviors and short events; (2) instantaneous sampling can provide accurate measurements of frequency and duration, especially at short scan intervals; (3) differences in behavioral results may occur depending on whether a correction for time out of sight is applied or not. Thus, 10 dams were observed from videos in the 2 h post-parturition. Ruminating, stereotypies, calf-biting and calf-butting were not recorded during the observation period. Other behaviors were observed only with continuous sampling or with continuous and instantaneous at 30-s scan intervals. The recoding of several behaviors was less accurate when applying longer scan intervals. Data from continuous and instantaneous sampling at 30-s scan intervals were compared with Wilcoxon test. Results showed no significant differences for posture, position in the pen and all behaviors (p > 0.05) except vocalizing (p = 0.003). The same test did not highlight significant differences due to method of dealing with out of sight for both sampling rules (p > 0.05). Correlation between continuous and instantaneous sampling were prevalently high at 30-s intervals and they decreased as the length of scan intervals increased for most behaviors. Results confirmed the first two assumptions suggesting that continuous sampling is more accurate, in particular for short and rare behaviors, and caution against the suitability of dam behavioral data collected using instantaneous sampling at scan intervals of minutes. The third assumption was not proven by this study. Results should be considered in light of the development of new technologies that relies on data acquired by sensors and imaging to monitor cow-calf welfare and behavior post-parturition.

A multi-center retrospective cohort study of patients with mCRPC who received lutetium Lu177 vipivotide tetraxetan.

89 Background: Lu177-vipivotide tetraxetan (Pluvicto) (Lu177-Plu) is the first FDA approved theragnostic for mCRPC. Since FDA approval in March 2022, there have been no published multicenter evaluations of real-world experiences with Lu177-Plu in the United States (US). We therefore present data from 2 academic centers on patient (pt) characteristics, treatment patterns and outcomes for mCRPC pts receiving SOC Lu177-Plu. Methods: Retrospective data was aggregated from University of Chicago &amp; Vanderbilt University on pt demographics, disease course and treatment for mCRPC pts who received SOC Lu177-Plu between 6/1/2022 and 9/1/2023. Research was conducted under IRBs VU211334 and IRB23-0718. 146 pts were identified who completed Lu177-Plu treatment by data cutoff 9/1/2023; their data is reported here. Results: Median age at cycle 1 (C1) was 72 years (range 49-93). Self-reported race was Black (23%), White (65%), Other/Unknown (UNK) (12%). Mean distance from home to treatment center was 79 mi. (range 1-1,317); 37% travelled &gt; 50 mi. At diagnosis, Gleason score was &gt;8 in 57%; 55% had locoregional disease, 44% had metastases, 1% were UNK. Median lines of prior systemic therapy were 4 (range 1-6), 95% received prior taxane(s) and 100% received prior androgen receptor signaling inhibitor (ARSI); 67% received 2 prior ARSI classes. PSMA-PET scan reported disease in bone in 93% of pts, lymph node 63%, liver 14%, lung 6%, other 25% (mostly prostate &amp; soft tissue). While undergoing 177Lu-Plu, 10% received concurrent ARSI (n=9 abiraterone, n=6 enzalutamide). Median cycles received was 3.5. 27 pts (18%) discontinued after C1, 46 (32%) after C2/3, 24 (16%) after C4/5 and 49 (34%) completed 6 cycles. 38% had a PSA &gt; 50% decline on treatment. 71 pts (49%) got scans between C1 and C6. Reasons cited for discontinuation prior to 6 cycles (n=97) included: progressive disease (including radiographic and/or PSA progression) (31%), progressive disease and toxicity (13%), toxicity (30%), clinical decline (including ECOG PS, transition to hospice or death) (23%), other (3%). 36 pts (25%) required supportive care with blood products (n=35 RBC, n=2 platelets). At data cutoff, 73 of 146 pts were alive (confirmed (n=66), unconfirmed (n=7)). Of deceased patients, median survival from C1 to death was 4.8 months (range 0.4-11.7). Conclusions: To our knowledge, this is the largest multicenter retrospective analysis of a racially diverse cohort of mCRPC pts receiving SOC Lu177-Plu following FDA approval in the US. PSA decline, median number of cycles received, fraction not requiring blood products in this cohort were all lower than in the VISION trial, likely due to baseline pt characteristics and potentially more liberal pt selection. Our data highlights numerous areas of need: expanded geographic access, optimized pt selection, standardization of scan type and interval on therapy and further data on concurrent therapy.

Micro nano antireflective and hydrophobic hierarchical structures ZnS by femtosecond laser

Antireflective hydrophobic hierarchical structures were fabricated on ZnS with ultralow reflectance by femtosecond laser. By adjusting the scanning interval, laser scanning speed and laser power, different kinds of hierarchical structures were obtained. The hierarchical structures combined the light trapping effect of micro-structures and effective refractive index medium effect of nano structures, greatly reduced the reflectance. At optimal parameters, the reflectance of ZnS with hierarchical structures decreased to lower than 1.4 % in the wavelength of 500–2500 nm. Besides, the hierarchical structures featured good hydrophobic performance with contact angle of 114°. This work provided a new way for the surface antireflection and hydrophobicity process, which could be widely used in the optical windows, and photoelectron devices.

Experimental study on femtosecond laser ablation of 4H–SiC substrate

Silicon carbide (SiC) is an ideal substrate for manufacturing high-power electronic devices and microwave devices and has broad application prospects. The surface treatment of SiC wafers plays a critical role and faces challenges in the semiconductor industry. Among the multiple treatment methods, the laser-based method has gradually attracted the attention of scholars. Therefore, this research uses a femtosecond laser to ablate 4H–SiC sliced wafers and analyzes the influence of key parameters, such as laser pulse energy, defocus amount, repetition frequency, and scanning intervals, on the laser ablation depth, width, and surface morphology. Scanning electron microscopy and laser coherence-focused microscopy were used to characterize the laser ablation surface. When the defocus amount was 6 mm, the microgroove profile formed by the laser was U-shaped. The scanning interval parameters had to be optimized to obtain the optimized surface roughness. The results show that the optimized surface roughness (Sa ) was 0.267 μm, and brittle fracture areas such as microcracks and pits on the original surface were removed. Effective removal facilitates further material surface processing, which provides valuable insights for similar researchers and benefits for the semiconductor industry.

Enhancing tribological performance of Ti6Al4V with additively manufactured porous architecture: A scanning interval approach

Enhancing tribological performance of Ti6Al4V with additively manufactured porous architecture: A scanning interval approach

Interval changes in four-dimensional flow-derived in vivo hemodynamics stratify aortic growth in type B aortic dissection patients

BackgroundAortic diameter growth in type B aortic dissection (TBAD) is associated with progressive aortic dilation, resulting in increased mortality in patients with both de novo TBAD (dnTBAD) and residual dissection after type A dissection repair (rTAAD). Preemptive thoracic endovascular aortic repair may improve mortality in patients with TBAD, although it is unclear which patients may benefit most from early intervention. In vivo hemodynamic assessment using four-dimensional (4D) flow magnetic resonance imaging (MRI) has been used to characterize TBAD patients with growing aortas. In this longitudinal study, we investigated whether changes over time in 4D flow derived true and false lumen (TL, FL) hemodynamic parameters correlate with aortic growth rate which is a marker of increased risk. MethodsWe retrospectively identified TBAD patients with baseline and follow-up 4D flow MRI at least 120 days apart. Patients with TBAD intervention before baseline or between scans were excluded. 4D flow MRI data analysis included segmentation of the TL and FL, followed by voxel-wise calculation of TL and FL total kinetic energy (KE), maximum velocity (MV), mean forward flow (FF), and mean reverse flow (RF). Changes over time (Δ) were calculated for all hemodynamic parameters. Maximal diameter in the descending aorta was measured from MR angiogram images acquired at the time of 4D flow. Aortic growth rate was defined as the change in diameter divided by baseline diameter and standardized to scan interval. Results32 patients met inclusion criteria (age: 56.9±14.1 years, Female: 13, n=19 rTAAD, n=13 dnTBAD). Mean follow up time was 538 days (range: 135-1689). Baseline aortic diameter did not correlate with growth rate. In the entire cohort, Δ FL MV (rho=0.37, p=.04) and Δ FL RF (rho=0.45, p=0.01) correlated with growth rate. In rTAAD only, Δ FL MV (rho=0.48, p=.04) and Δ FL RF (rho=0.51, p=0.03) correlated with growth rate, while in dnTBAD only, Δ TL KE (rho=0.63, p=.02) and Δ TL MV (rho=0.69, p=.01) correlated with growth rate. Conclusions4D flow derived longitudinal hemodynamic changes correlate with aortic growth rate in TBAD and may provide additional prognostic value for risk stratification. 4D flow MRI could be integrated into existing imaging protocols to allow for identification of TBAD patients who would benefit from preemptive surgical or endovascular intervention.

Heitt Mjölnir: a heated miniature triaxial apparatus for 4D synchrotron microtomography.

Third- and fourth-generation synchrotron light sources with high fluxes and beam energies enable the use of innovative X-ray translucent experimental apparatus. These experimental devices access geologically relevant conditions whilst enabling in situ characterization using the spatial and temporal resolutions accessible at imaging beamlines. Here, Heitt Mjölnir is introduced, a heated miniature triaxial rig based on the design of Mjölnir, but covering a wider temperature range and larger sample volume at similar pressure capacities. This device is designed to investigate coupled thermal, chemical, hydraulic and mechanical processes from grain to centimetre scales using cylindrical samples of 10 mm × 20 mm (diameter × length). Heitt Mjölnir can simultaneously reach confining (hydraulic) pressures of 30 MPa and 500 MPa of axial stress with independently controlled sample pore fluid pressure < 30 MPa. This internally heated apparatus operates to temperatures up to 573 K with a minimal vertical thermal gradient in the sample of <0.3 K mm-1. This new apparatus has been deployed in operando studies at the TOMCAT (Swiss Light Source), I12 JEEP (Diamond Light Source) and PSICHÉ (Synchrotron SOLEIL) beamlines for 4D X-ray microtomography with scan intervals of a few minutes. Heitt Mjölnir is portable and modular, allowing a wide range of 4D characterizations of low-grade metamorphism and deformational processes. It enables spatially and temporally resolved fluid-rock interaction studies at conditions of crustal reservoirs and is suitable for characterization of material properties in geothermal, carbonation or subsurface gas storage applications. Technical drawings and an operation guide are included in this publication.