Outcomes of Acute Ischemic Stroke Among Patients with Renal Cell Carcinoma: A Nationwide Analysis.

INTRODUCTION: Renal cell carcinoma (RCC) has been associated with an increased risk for acute ischemic stroke (AIS). As individuals with cancer who experience AIS tend to face higher mortality rates compared to AIS patients without cancer, recognizing the implications of RCC in AIS is crucial for identifying high-risk patients for major complications and directing management strategies. OBJECTIVE: To examine risk factors, interventions, and outcomes for patients with AIS stratified by their RCC diagnosis. METHODS: The National Inpatient Sample (NIS) database was queried for the period 2010-2019 using International Classification of Disease 10th Edition (ICD-10) codes for acute ischemic stroke and renal malignancies. We assessed demographic information, comorbidities, and clinical interventions between patients presenting with AIS, with and without renal malignancies. A logistic regression model was employed to further examine mortality outcomes. RESULTS: Among 1,609,817 patients identified with AIS, 2,068 (0.12%) had a concomitant diagnosis of RCC. AIS patients with RCC were older (72.09 yrs. vs. 70.9 yrs., p < 0.01), more often white (72.05% vs. 68.16%, p < 0.01), and had similar stroke severity scores. RCC patients received less tissue plasminogen activator (tPA; 4.98% vs. 6.2%, p = 0.02) but underwent endovascular mechanical thrombectomy (MT) at similar rates. RCC patients had more complications (p < 0.01) as well as longer hospital stays (8.19 days vs. 5.98 days, p < 0.01), and higher rates of mortality (11.27% vs. 5.63%, p < 0.01), when compared to their non-RCC counterparts. Propensity score-adjusted analysis largely confirmed these findings, with RCC being positively associated with in-hospital mortality (OR: 1.373, p < 0.01) and longer stays (OR: 2.591, p < 0.01). CONCLUSION: In addition to describing the demographics and clinical course of AIS patients diagnosed with RCC, our study underscores the substantial impact of RCC on AIS outcomes. Despite experiencing strokes of similar severity, AIS patients diagnosed with RCC are at a heightened risk of complications, including thromboembolic events and infections, leading to elevated in-hospital mortality rates and prolonged hospital stays.

[Experience of Providing Intensive Rehabilitation Care to a School-Aged Child With Living-Donor Lobar Lung Transplantation].

The post-operative intensive care experience of a school-aged child who received living-donor bilateral lobar lung transplantation due to acute respiratory distress syndrome and interstitial pulmonary fibrosis is discussed in this paper. The patient received lungs donated by her parents in a "living-donor bilateral lobar lung transplantation" due to severe lung function impairment. The patient felt anxious due to her long-term hospitalization for preoperative evaluation, various invasive treatments, and postoperative rehabilitation. During the care period from October 25th, 2022, to December 29th, 2022, the author collected data via direct care, interviews, medical record reviews, and interactions with the patient and her family. An assessment of the patient's physical, mental, and social integrity was made, and the collected data were organized and analyzed to identify health issues such as lack of activity endurance, imbalanced nutrition below bodily requirements, and anxiety. After the lung transplantation operation, the interdisciplinary team worked collaboratively to develop a care plan to improve cardiopulmonary endurance and enhance the quality of care for the patient through early care and rehabilitation via proactive care. This care plan included encouraging the patient and her parents to express their fears and feelings and using flashcards to teach them about dietary management and the proper performance of lung rehabilitation. These measures encouraged the parents to engage in care, properly prepare for discharge care, and receive care education. As this is the first case of living-donor lobar lung transplantation in Taiwan, this valuable nursing experience is expected to provide future care teams with a reference on the related nursing process and care experience for similar cases.

Managing type 1 diabetes of a child: Parents' perspectives.

PURPOSE: Managing type 1 diabetes (T1D) challenges children and their parents. Parents need to learn the necessary skills and later transfer the responsibility of care to their children as they develop. The transition process involves autonomy in behaviour and decision-making. This study explores the shared management experiences of Taiwanese parents and their children with type 1 diabetes. DESIGN AND METHODS: This study employed a qualitative design using a grounded theory approach. Purposive sampling was used at a medical centre in Taiwan for participant recruitment. Twenty-nine parents of children who had been diagnosed with T1D were interviewed in-depth. Data were analysed using constant comparison and repeated verification. RESULTS: After a child was diagnosed with T1D, the parents initiated 'Life-long lesson: Growing together with the child on the road to normality'. Three main categories emerged: 'confronting the disease diagnosis', 'establishing supportive and collaborative involvement' and 'assisting the child in building a sense of belonging'. Sub-categories within each significant category were also included. CONCLUSIONS: Taiwanese parents perhaps have a controlling or directive role for a long period in their child's lives and shared management of their health condition. This study's findings can help healthcare workers better understand the process of parents' shared management of T1D with their children and how to best communicate with children about the disease and care in accordance with the child's stage of development.

A gap in the data: Defining, identifying, and tracking children with medical complexity in the child welfare system.

BACKGROUND: Among nearly 400,000 children in US foster care, an estimated 10 % are medically complex. Yet, population-level data about children with medical complexity (CMC) served by the child welfare system, both for prevention and foster care services, are largely unavailable. OBJECTIVE: To understand how US child welfare agencies define, identify, and track CMC. PARTICIPANTS AND SETTING: Child welfare agencies across the US. METHODS: Agencies were recruited to complete a survey as part of a larger study exploring how CMC are served by the child welfare system. Survey responses related to defining, identifying, and tracking CMC were included in analysis. Descriptive statistical analysis was conducted with Stata. Qualitative content and thematic analysis were applied to free text responses. RESULTS: Surveys were completed by agencies from 28 states and 2 major cities. Nearly half of the agencies did not have a clear definition to identify CMC; those that did have a definition often lacked standardization. The majority of agencies could not easily identify CMC or access CMC-related data within data systems. Agencies described lack of a clear definition as a barrier to collecting population level data. CONCLUSIONS: Many US child welfare agencies lack a clear definition to identify and track CMC, impacting the ability to tailor care and service delivery to meet their unique needs. To address this, a clear definition for CMC should be developed and consistently applied within child welfare data systems. Once CMC are identifiable, future research can collect population-level data and provide recommendations for best practices and policies.

A double-hit: End-stage renal disease patients suffer worse outcomes in intracerebral hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) carries significant morbidity and mortality. Previous single-center retrospective analysis suggests that end-stage renal disease (ESRD) is a risk factor for severe ICH and worse outcomes. This investigation aims to examine the impact of ESRD on ICH severity, complications, and outcomes using a multicenter national database. METHODS: The International Classification of Disease, Ninth and Tenth Revision Clinical Modification codes were used to query the National Inpatient Sample for patients with ICH and ESRD between 2010 and 2019. Primary endpoints were the functional outcome, length of stay (LOS), and in-hospital mortality. Multivariate variable regression models and a propensity-score matched analysis were established to analyze patient outcomes associated with baseline patient characteristics. RESULTS: We identified 211,266 patients with ICH, and among them, 7,864 (3.77%) patients had a concurrent diagnosis of ESRD. Patients with ESRD were younger (60.85 vs. 67.64, P < 0.01) and demonstrated increased ICH severity (0.78 vs. 0.77, P < 0.01). ESRD patients experienced higher rates of sepsis (15.9% vs. 6.15%, P < 0.01), acute myocardial infarction (8.05% vs. 3.65%, P < 0.01), and cardiac arrest (5.94% vs. 2.4%, P < 0.01). In addition, ESRD predicted poor discharge disposition (odds ratio [OR]: 2.385, 95% confidence interval [CI]: 2.227-2.555, P < 0.01), longer hospital LOS (OR: 1.629, 95% CI: 1.553-1.709, P < 0.01), and in-hospital mortality (OR: 2.786, 95% CI: 2.647-2.932, P < 0.01). CONCLUSIONS: This study utilizes a multicenter database to analyze the effect of ESRD on ICH outcomes. ESRD is a significant predictor of poor functional outcomes, in-hospital mortality, and prolonged stay in the ICH population.

Frailty as a Predictor of Outcomes in Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis.

Frailty is an emerging concept in clinical practice used to predict outcomes and dictate treatment algorithms. Frail patients, especially older adults, are at higher risk for adverse outcomes. Aneurysmal subarachnoid hemorrhage (aSAH) is a neurosurgical emergency associated with high morbidity and mortality rates that have previously been shown to correlate with frailty. However, the relationship between treatment selection and post-treatment outcomes in frail aSAH patients is not established. We conducted a meta-analysis of the relevant literature in accordance with PRISMA guidelines. We searched PubMed, Embase, Web of Science, and Google Scholar using "Subarachnoid hemorrhage AND frailty" and "subarachnoid hemorrhage AND frail" as search terms. Data on cohort age, frailty measurements, clinical grading systems, and post-treatment outcomes were extracted. Of 74 studies identified, four studies were included, with a total of 64,668 patients. Percent frailty was 30.4% under a random-effects model in all aSAH patients (p < 0.001). Overall mortality rate of aSAH patients was 11.7% when using a random-effects model (p < 0.001). There was no significant difference in mortality rate between frail and non-frail aSAH patients, but this analysis only included two studies and should be interpreted cautiously. Age and clinical grading, rather than frailty, independently predicted outcomes and mortality in aSAH patients.

Viscoelastic hydrogels for interrogating pancreatic cancer-stromal cell interactions.

The tumor microenvironment (TME) is known to direct cancer cell growth, migration, invasion into the matrix and distant tissues, and to confer drug resistance in cancer cells. While multiple aspects of TME have been studied using in vitro, ex vivo, and in vivo tumor models and engineering tools, the influence of matrix viscoelasticity on pancreatic cancer cells and its associated TME remained largely unexplored. In this contribution, we synthesized a new biomimetic hydrogel with tunable matrix stiffness and stress-relaxation for evaluating the effect of matrix viscoelasticity on pancreatic cancer cell (PCC) behaviors in vitro. Using three simple monomers and Reverse-Addition Fragmentation Chain-Transfer (RAFT) polymerization, we synthesized a new class of phenylboronic acid containing polymers (e.g., poly (OEGA-s-HEAA-s-APBA) or PEHA). Norbornene group was conjugated to HEAA on PEHA via carbic anhydride, affording a new NB and BA dually modified polymer - PEHNBA amenable for orthogonal thiol-norbornene photopolymerization and boronate ester diol complexation. The former provided tunable matrix elasticity, while the latter gave rise to matrix stress-relaxation (or viscoelasticity). The new PEHNBA polymers were shown to be highly cytocompatible for in situ encapsulation of PCCs and cancer-associated fibroblasts (CAFs). Furthermore, we demonstrated that hydrogels with high stress-relaxation promoted spreading of CAFs, which in turns promoted PCC proliferation and spreading in the viscoelastic matrix. Compared with elastic matrix, viscoelastic gels upregulated the secretion of soluble proteins known to promote epithelial-mesenchymal transition (EMT). This study demonstrated the crucial influence of matrix viscoelasticity on pancreatic cancer cell fate and provided an engineered viscoelastic matrix for future studies and applications related to TME.

Association of grit and overall survival in patients undergoing nephrectomy for renal cell carcinoma.

Background: Quantifying grit with the Short Grit Scale (Grit-S) has shown ability to predict success in various academic and professional domains. Grit has yet to be analyzed in patients with cancer. Methods: This study is a longitudinal analysis of prospectively distributed Grit-S surveys to patients undergoing radical or partial nephrectomy. Patients who completed a preoperative Grit-S survey with confirmed renal cell carcinoma (RCC) were included in the analysis. The relationship between preoperative grit scores and overall survival (OS) was determined using Cox proportional-hazard models and Kaplan-Meier analysis. Results: A total of 323 patients with RCC that completed the Grit-S survey prior to nephrectomy were included in the study. Median Grit score was 3.9. Most patients were male (67.5%), White (69.3%), and greater than 60 years old (57.0%) with a median age of 62 at the time of surgery. Patients scoring above or below the median grit score had similar baseline characteristics. As a binary variable, lower preoperative grit was significantly associated with shorter OS [hazard ratio (HR) =2.02, 95% confidence interval (CI): 1.12-3.63, P=0.019] on multivariable analysis. Unit changes in grit were not significantly associated with OS (HR =0.77, 95% CI: 0.53-1.14, P=0.193). Conclusions: Lower grit scores may predict decreased OS in RCC patients undergoing nephrectomy. The Grit-S survey may have utility in preoperative evaluation. Further research assessing grit in other malignancies and how to psychologically optimize patients prior to surgery are needed.

Dissolvable microgel-templated macroporous hydrogels for controlled cell assembly.

Mesenchymal stem cells (MSCs)-based therapies have been widely used to promote tissue regeneration and to modulate immune/inflammatory response. The therapeutic potential of MSCs can be further improved by forming multi-cellular spheroids. Meanwhile, hydrogels with macroporous structures are advantageous for improving mass transport properties for the cell-laden matrices. Herein, we report the fabrication of MSC-laden macroporous hydrogel scaffolds through incorporating rapidly dissolvable spherical cell-laden microgels. Dissolvable microgels were fabricated by tandem droplet-microfluidics and thiol-norbornene photopolymerization using a novel fast-degrading macromer poly(ethylene glycol)-norbornene-dopamine (PEGNB-Dopa). The cell-laden PEGNB-Dopa microgels were subsequently encapsulated within another bulk hydrogel matrix, whose porous structure was generated efficiently by the rapid degradation of the PEGNB-Dopa microgels. The cytocompatibility of this in situ pore-forming approach was demonstrated with multiple cell types. Furthermore, adjusting the stiffness and cell adhesiveness of the bulk hydrogels afforded the formation of solid cell spheroids or hollow spheres. The assembly of solid or hollow MSC spheroids led to differential activation of AKT pathway. Finally, MSCs solid spheroids formed in situ within the macroporous hydrogels exhibited robust secretion of HGF, VEGF-A, IL-6, IL-8, and TIMP-2. In summary, this platform provides an innovative method for forming cell-laden macroporous hydrogels for a variety of future biomedical applications.

Low free testosterone is associated with increased mortality in frail surgical patients.

BACKGROUND: Preoperative frailty has been associated with adverse postoperative outcomes. Additionally, low testosterone has been associated with physical frailty and cognitive decline. However, the impact of simultaneous frailty and low testosterone on surgical outcomes is understudied. METHODS: Preoperative frailty status and testosterone levels were obtained in patients undergoing a diverse range of surgical procedures. Preoperative frailty was evaluated independently and in combination with testosterone through the creation of composite risk groups. Relationships between preoperative frailty and composite risk groups with overall survival were determined using Kaplan-Meier and logistic regression analyses. Bivariate analysis was used to determine the associations between frailty and testosterone status on postoperative complications, length of hospital stay, and readmission rates. RESULTS: Median age of the cohort was 63 years, and the median follow-up time was 105 weeks. Thirty-one patients (23%) were frail, and 36 (27%) had low free testosterone. Bivariate analysis demonstrated a statistically significant relationship between preoperative frailty and overall survival (P = .044). In multivariate analysis, coexisting frailty and low free testosterone were significantly associated with decreased overall survival (hazard ratio 4.93, 95% confidence interval, 1.68-14.46, P = .004). CONCLUSION: We observed preoperative frailty, both independently and in combination with low free testosterone levels, to be significantly associated with decreased overall survival across various surgical procedures. Personalizing the surgical risk assessment through the incorporation of preoperative frailty and testosterone status may serve to improve the prognostication of patients undergoing major surgery.

Injectable Acylhydrazone-Linked RAFT Polymer Hydrogels for Sustained Protein Release and Cell Encapsulation.

A new class of temperature responsive polymer, termed PADO, is synthesized by reversible addition-fragmentation chain-transfer polymerization. Synthesized from copolymerization of diacetone acrylamide (DAAM), di(ethylene glycol) ethyl ether acrylate, and oligo(ethylene glycol) methyl ether acrylate, PADO polymer phase separates at temperature above its lower critical solution temperature (36-42 °C) due to enhanced hydrophobic interactions between the short ethylene glycol side chains. Solution of PADO polymers exhibit injectable shear-thinning properties and reach sol-gel transition rapidly (<5 min) at 37 °C. When the ketone moieties on DAAM are linked by adipic acid dihydrazdie, PADO polymers form crosslinked and injectable acylhydrazone hydrogels, which are hydrolytically degradable at a mild acidic environment owing to the pH sensitive acylhydrazone bonds. The pH-responsive degradation kinetics can be controlled by tuning polymer contents and ketone/hydrazide ratio. Importantly, the injectable PADO hydrogels are highly cytocompatible and can be easily formulated for pH-responsive sustained protein delivery.

Segmentation and Linear Measurement for Body Composition Analysis using Slice-O-Matic and Horos.

Body composition is associated with risk of disease progression and treatment complications in a variety of conditions. Therefore, quantification of skeletal muscle mass and adipose tissues on Computed Tomography (CT) and/or Magnetic Resonance Imaging (MRI) may inform surgery risk evaluation and disease prognosis. This article describes two quantification methods originally described by Mourtzakis et al. and Avrutin et al.: tissue segmentation and linear measurement of skeletal muscle. Patients' cross-sectional image at the midpoint of the third lumbar vertebra was obtained for both measurements. For segmentation, the images were imported into Slice-O-Matic and colored for skeletal muscle, intramuscular adipose tissue, visceral adipose tissue, and subcutaneous adipose tissue. Then, surface areas of each tissue type were calculated using the tag surface area function. For linear measurements, the height and width of bilateral psoas and paraspinal muscles at the level of the third lumbar vertebra are measured and the calculation using these four values yield the estimated skeletal muscle mass. Segmentation analysis provides quantitative, comprehensive information about the patients' body composition, which can then be correlated with disease progression. However, the process is more time-consuming and requires specialized training. Linear measurements are an efficient and clinic-friendly tool for quick preoperative evaluation. However, linear measurements do not provide information on adipose tissue composition. Nonetheless, these methods have wide applications in a variety of diseases to predict surgical outcomes, risk of disease progression and inform treatment options for patients.

Facile Synthesis of Rapidly Degrading PEG-Based Thiol-Norbornene Hydrogels.

An alternate synthesis route was developed to prepare norbornene-functionalized poly(ethylene glycol) (PEG) from reacting multiarm PEG with carbic anhydride. The macromer, PEGNBCA, permits photo-cross-linking of thiol-norbornene hydrogels with kinetics comparable to conventional PEGNB macromer. In addition, PEGNBCA provides an additional carboxylate group for further conjugation with amine-bearing molecules. Interestingly, PEGNBCA thiol-norbornene hydrogels are highly susceptible to hydrolytic degradation through enhanced ester hydrolysis. The ester linkage is further weakened after the secondary conjugation, resulting in extremely rapid degradation of PEGNB hydrogels. More importantly, the degradation can be readily adjusted via tuning macromer compositions, with complete degradation time ranging from hours to weeks. The PEGNBCA hydrogels are also highly cytocompatible toward various cell types, providing opportunities for future applications in tissue engineering and advanced biofabrication.

Roles of Akt and ERK in mTOR-Dependent Antidepressant Effects of Vanillic Acid.

Vanillic acid, an oxidized form of vanilla, is a flavoring agent with a creamy odor. Several studies have reported the neuroprotective effects of vanillic acid, which are predominantly associated with anti-inflammatory and antioxidative properties. The anti-inflammatory and antioxidative properties may result from Akt or ERK signaling activation. The activation of the mammalian target of rapamycin (mTOR), a key downstream target of Akt and ERK signaling, is a crucial therapeutic target for treating depression. However, the antidepressant effects of vanillic acid remain unknown. The present study applied the forced swim test (FST) to investigate the antidepressant effects of vanillic acid and its association with Akt, ERK, and mTOR signaling and upstream α-amino-3-hydroxy-5-methyl-4-isoxazolepropionaic acid receptor (AMPAR) in the prefrontal cortex (PFC) of mice. Vanillic acid demonstrated antidepressant effects by significantly reducing behavioral despair in the FST. None of the treatments changed locomotor activity. Additionally, vanillic acid increased AMPAR throughput, Akt, and mTOR signaling but not ERK signaling in the PFC. NBQX (an AMPAR blocker), MK 2206 (an Akt blocker), and rapamycin (an mTOR blocker) used in pretreatment attenuated the antidepressant effects of vanillic acid, but SL327 (an ERK inhibitor) did not. The immunochemical results indicated that the antidepressant effects of vanillic acid depend on the AMPAR-Akt-mTOR signaling transduction pathway. Our findings reveal an Akt-dependent, but ERK-independent, the mechanism underlying the antidepressant effects of vanillic acid, which may be beneficial for some patients with depression.

Polystyrene-block-Polydimethylsiloxane as a Potential Silica Substitute for Polysiloxane Reinforcement.

Here we report microphase-separated poly(styrene-block-dimethylsiloxane) (PS-b-PDMS) as a reinforcing filler in PDMS thermosets that overcomes the long-standing problem of aging in the processing of silica-reinforced silicone. Surprisingly, PS-b-PDMS reinforced composites display comparable mechanical performance to silica-modified analogs, even though the modulus of PS is much smaller than that of silica and there is no evidence of percolation with respect to the rigid PS domains. We have found that a few unique characteristics contribute to the reinforcing performance of PS-b-PDMS. The strong self-assembly behavior promotes batch-to-batch repeatability by having well-dispersed fillers. The structure and size of the fillers depend on the loading and characteristics of both filler and matrix, along with the shear effect. The reinforcing effect of PS-b-PDMS is mostly brought by the entanglements between the corona layer of the filler and the matrix, rather than the hydrodynamic reinforcement of the PS phase.

In Situ Formed Pt3Ti Nanoparticles on a Two-Dimensional Transition Metal Carbide (MXene) Used as Efficient Catalysts for Hydrogen Evolution Reactions.

The design of efficient catalysts capable of delivering high currents at low overpotentials for hydrogen evolution reactions (HERs) is urgently needed to use catalysts in practical applications. Herein, we report platinum (Pt) alloyed with titanium (Ti) from the surface of Ti3C2Tx MXenes to form Pt3Ti intermetallic compound (IMC) nanoparticles (NPs) via in situ coreduction. In situ X-ray absorption spectroscopy (XAS) indicates that Pt undergoes a temperature-dependent transformation from single atoms to intermetallic compounds, and the catalyst reduced at 550 °C exhibits a superior HER performance in acidic media. The Pt/Ti3C2Tx-550 catalyst outperforms commercial Pt/Vulcan and has a small overpotential of 32.7 mV at 10 mA cm-2 and a low Tafel slope of 32.3 mV dec-1. The HER current was normalized by the mass and dispersion of Pt, and the mass activity and specific activity of Pt/Ti3C2Tx-550 are 4.4 and 13 times higher, respectively, than those of Pt/Vulcan at an overpotential of 70 mV. The density functional theory (DFT) calculations suggest that the (111)- and (100)-terminated Pt3Ti nanoparticles exhibit *H binding comparable to Pt(111), while the (110) termination has an *H adsorption that is too exergonic, thus poisoned in the low overpotential region. This work demonstrates the potential of MXenes as platforms for the design of electrocatalysts and may spur future research for other MXene-supported metal catalysts that can be used for a wide range of electrocatalytic reactions.

Thin Biobased Transparent UV-Blocking Coating Enabled by Nanoparticle Self-Assembly.

A waterborne, UV-blocking, and visually transparent nanocomposite coating was formulated with ZnO nanoparticles and 2-hydroxyethyl cellulose (HEC). The coating is highly effective (<5% UV and ∼65% visible transmittance), and the film thickness (0.2-2.5 µm) is ∼100 times thinner than the conventional coatings of similar UV-blocking performance. The superior properties are due to the fractal structures of ZnO nanoparticles assembled within the HEC matrix, revealed by scanning electron microscopy and small-angle X-ray scattering (SAXS). Changing the binder to 2-hydroxyethyl starch (HES) diminishes the UV-blocking performance, as ZnO nanoparticles form dense globular aggregates, with an aggregation number measured by SAXS 3 orders of magnitude larger than the HEC coating. Since HEC and HES share the same repeating glucose unit in the polymer backbone, it suggests that the conformational characteristics of the binder polymer have a strong influence on the nanoparticle aggregation, which plays a key role in determining the optical performance. Similar structures were achieved with TiO2 nanoparticles. This study not only offers a cost-effective and readily scalable method to fabricate transparent UV-blocking coating but also demonstrates that the unique fractal aggregation structures in a nanocomposite material can provide high performance and functionality without fully dispersing the nanoparticles.

Sensitivity enhancement of methacrylic acid gel dosimeters by incorporating iodine for computed tomography scans.

PURPOSE: Polymer gel dosimeters provide three-dimensional absorbed dose information and have gradually become a popular tool for quality assurance in radiotherapy. This study aims to incorporate iodine into the MAGAT-based gel as radiation sensitizer and investigate whether it can be used to measure the radiation dose and slice thickness for CT scans. METHODS: The nMAGAT(I) gel was doped with 0.03, 0.05, and 0.07-M iodine. The absorbed dose was delivered using a CT scanner (Alexion 16, Toshiba Medical Systems, Japan) with tube voltages of 80, 100, 120, and 135 kVp. The irradiated nMAGAT(I) gel was read using a cone beam optical CT scanner to produce dose-response curves. The nMAGAT(I) gel was used to obtain the slice sensitivity profile (SSP) and the CT dose index (CTDI) for quality assurance of CT scans. RESULTS: The 0.07-M iodine-doped nMAGAT(I) gel exhibited maximum sensitivity with the dose enhancement ratio of 2.12. The gel was chemically stable 24 h after its preparation, and the polymerization process was completed 24-48 h after the irradiation. For CT quality assurance, the full width at half maximum measured by the nMAGAT(I) gel matched the nominal slice thickness of CT. The CTDI at center, CTDI at peripheral, and weighted CTDI obtained by the nMAGAT(I) gel differed from those obtained by the ionization chamber by -4.2%, 3.1%, and 0.7%, respectively. CONCLUSIONS: The nMAGAT(I) gel can be used to assess radiation doses and slice thickness in CT scans, thus rendering it a potential quality assurance tool for CT and other radiological diagnostic applications.

Using Cine-Averaged CT With the Shallow Breathing Pattern to Reduce Respiration-Induced Artifacts for Thoracic Cavity PET/CT Scans.

OBJECTIVE. PET/CT provides a fusion of both anatomic and functional information. However, because of the temporal difference of both modalities and respiratory motion of lungs, misregistration of lesions is frequently observed on thoracic PET/CT scans. The effect of cine-averaged CT (CACT) acquisition incorporated with the shallow breathing pattern of patients on the improvement of registration and quantification of lesions was investigated. MATERIALS AND METHODS. Thirty patients with cancer who underwent routine PET/CT followed by CACT of the thoracic region were enrolled. The misalignment between PET/helical CT (HCT) and PET/CACT was calculated. In addition, the PET data were attenuation-corrected by HCT and CACT images, and the maximum standardized uptake value (SUVmax) was evaluated. RESULTS. All lesions in the PET/HCT images showed misalignment larger than 5 mm, whereas only 33% of lesions in the PET/CACT images showed misalignment larger than 5 mm. The mean values of the maximum misalignment of the lesions in PET/HCT and PET/CACT images were 14.10 ± 6.26 mm and 5.92 ± 4.31 mm, respectively. Seven percent of the lesions had an increase in SUVmax of more than 20%, and 47% showed a slight increase in SUVmax of less than 5% after applying CACT. The mean percentage difference between the SUVmax of CACT and that of HCT was 12%. CONCLUSION. Using the CACT technique and the shallow breathing pattern effectively reduces misregistration of lesions and recovers the underestimated SUVmax. The CACT method can be applied in clinical practice of thoracic PET/CT for better cancer management.

Fate of distal aorta after acute type A aortic dissection repair: Change and persistency of postoperative false lumen status.

BACKGROUND: The role of false lumen patency related to aortic growth, re-interventions, and post-discharge mortality in the chronic phase of repaired type A acute aortic dissection (TAAAD) remains controversial. We investigated the role of postoperative false lumen patency during long-term follow-up. METHODS: Based on postoperative CT images of 70 candidates, 58 eligible patients without alteration of false lumen status were assigned into three groups: complete patency, partial patency, and complete thrombosis. Aortic growth of 7 levels was analyzed. RESULTS: Persistent complete patency in post-operative TAAAD presents faster expansion of aortic diameter (95% CI, 0.35 to 11.52; P=0.038; B=5.935) and more patients with growth rate>5mm/year (P=0.029). The persistent status of false lumen does not predict post-discharge mortality (P=0.479). History of coronary artery disease (CAD) is the only independent predictor of post-discharge mortality. CONCLUSIONS: In TAAAD patients without change of postoperative false lumen status, completely patent false lumen presents faster aortic growth and more patients with growth rate>5mm/year. False lumen status does not correlate with late survival. Here we provide an insight into persistent postoperative false lumen in TAAAD patients and may help cast light on aortic dissection in this specific subgroup to improve their late outcomes.