Management of ulcerated finger pad tophi.

Finger pad tophi are an unusual but not very rare presentation of uncontrolled gout. Unlike tophaceous lesions of other locations, finger pad tophi are often difficult to diagnose at presentation due to resemblance to a variety of nodular lesions, coexistence with other connective tissue disorders and sometimes occurrence in asymptomatic hyperuricemia. They also pose a therapeutic dilemma due to a lack of clear treatment guidelines. Several case reports of finger pad tophi have been published before, focusing mainly on diagnosis and medical management. We discuss here a case of thumb pad tophi as primary presentation of undiagnosed asymptomatic hyperuricemia and treated surgically with excision and full-thickness skin graft along with urate-lowering therapy. This article highlights the diagnosis and treatment of finger pad tophi. We also discuss the surgical management of tophaceous lesions of hands and digits.

Stress, Immune Function and Collegiate Holiday Drinking: A Pilot Study.

BACKGROUND/AIMS: Social aspects of collegiate holiday drinking have been studied frequently, but physiological consequences are often overlooked. This study examined self-reported stress, endocrine and immune indicators in students at an American university before and after their week-long spring break (SB) holiday. METHODS: Participants (n = 27; 9 males) provided saliva samples and completed surveys pre- and post-SB. Based on their cortisol reaction to SB, participants were grouped as cortisol nonresponders (CNR; n = 14) or increasers (CI; n = 13). Groups were matched on demographics, baseline alcohol use, family history of alcoholism, and SB plans. Differences over time and between groups were examined for α-amylase, quantity/frequency of alcohol use (quantity/frequency index, QFI) and the immunoglobulin A (IgA) to albumin ratio (IgA:albumin). RESULTS: α-Amylase decreased over time. A time × group interaction was noted for QFI, in which CNRs increased drinking over SB, but CIs did not. Time and time × group effects occurred for IgA:albumin. CIs decreased IgA:albumin over SB, whereas CNRs did not. Pre-SB QFI and pre-/post-SB QFI changes were correlated with changes in IgA:albumin. CONCLUSION: These findings support previously published relationships between blunted cortisol responses and risk for problem drinking, as well as elevated cortisol and decreased immune response. These data also highlight the importance of physiological measures in the study of collegiate holiday drinking.

Deep silicon photon-counting CT: A first simulation-based study for assessing perceptual benefits across diverse anatomies.

OBJECTIVES: To assess perceptual benefits provided by the improved spatial resolution and noise performance of deep silicon photon-counting CT (Si-PCCT) over conventional energy-integrating CT (ECT) using polychromatic images for various clinical tasks and anatomical regions. MATERIALS AND METHODS: Anthropomorphic, computational models were developed for lungs, liver, inner ear, and head-and-neck (H&N) anatomies. These regions included specific abnormalities such as lesions in the lungs and liver, and calcified plaques in the carotid arteries. The anatomical models were imaged using a scanner-specific CT simulation platform (DukeSim) modeling a Si-PCCT prototype and a conventional ECT system at matched dose levels. The simulated polychromatic projections were reconstructed with matched in-plane resolutions using manufacturer-specific software. The reconstructed pairs of images were scored by radiologists to gauge the task-specific perceptual benefits provided by Si-PCCT compared to ECT based on visualization of anatomical and image quality features. The scores were standardized as z-scores for minimizing inter-observer variability and compared between the systems for evidence of statistically significant improvement (one-sided Wilcoxon rank-sum test with a significance level of 0.05) in perceptual performance for Si-PCCT. RESULTS: Si-PCCT offered favorable image quality and improved visualization capabilities, leading to mean improvements in task-specific perceptual performance over ECT for most tasks. The improvements for Si-PCCT were statistically significant for the visualization of lung lesion (0.08 ± 0.89 vs. 0.90 ± 0.48), liver lesion (-0.64 ± 0.37 vs. 0.95 ± 0.55), and soft tissue structures (-0.47 ± 0.90 vs. 0.33 ± 1.24) and cochlea (-0.47 ± 0.80 vs. 0.38 ± 0.62) in inner ear. CONCLUSIONS: Si-PCCT exhibited mean improvements in task-specific perceptual performance over ECT for most clinical tasks considered in this study, with statistically significant improvement for 6/20 tasks. The perceptual performance of Si-PCCT is expected to improve further with availability of spectral information and reconstruction kernels optimized for high resolution provided by smaller pixel size of Si-PCCT. The outcomes of this study indicate the positive potential of Si-PCCT for benefiting routine clinical practice through improved image quality and visualization capabilities.

Amyloid Light-Chain (AL) Amyloidosis of the Trachea Associated With an Indolent B-cell Neoplasm.

We report the case of a 66-year-old woman who was diagnosed with localized tracheal amyloid light-chain (AL) amyloidosis caused by an underlying B-cell neoplasm. The diagnosis was confirmed through subsequent bronchoscopy and biopsies; however, she experienced a challenging episode of hypoxic respiratory failure that required intervention. Repeat bronchoscopies showed persistent subglottic stenosis and tracheobronchomalacia, which led to tracheal debulking surgery and additional interventions. The patient's treatment began with rituximab, zanubrutinib, and dexamethasone with outpatient follow-up. The rarity of tracheobronchial amyloidosis and its connection to B-cell malignancies are highlighted, emphasizing the challenges in diagnosis and the importance of tailored treatment strategies. The patient's clinical course, characterized by atypical respiratory symptoms, delayed diagnosis, and an evolving treatment approach, underscores the complexities of managing such a rare and intricate case.

Women who pre-game: A study of stress and alcohol use in female collegiate predrinkers.

Introduction: This study examined the relationship between stress and pre-gaming (i.e., drinking prior to going out to an event) in female college students. Methods: Thirty-four female college students were grouped as pre-gamers or non-pre-gamers based on self-reported drinking patterns. They completed surveys about alcohol use and mental health and provided a set of salivary cortisol samples upon waking, 30 min later, and at 10am on the same day. Results: Pre-gamers and non-pre-gamers did not differ on demographics or psychosocial variables. Pre-gamers reported riskier drinking overall and had greater endorsement of social, coping, and enhancement drinking motives. Pre-gamers also had lower cortisol levels 30 min after waking and exhibited attenuated CAR. Conclusions: Female collegiate pre-gamers may differ from their peers not only in terms of alcohol consumption and drinking motives, but also on attenuated CAR, a physiological biomarker associated with stress dysregulation and vulnerability to addictive behaviors.

Can Photon-Counting CT Improve Estimation Accuracy of Morphological Radiomics Features? A Simulation Study for Assessing the Quantitative Benefits from Improved Spatial Resolution in Deep Silicon-Based Photon-Counting CT.

RATIONALE AND OBJECTIVES: Deep silicon-based photon-counting CT (Si-PCCT) is an emerging detector technology that provides improved spatial resolution by virtue of its reduced pixel sizes. This article reports the outcomes of the first simulation study evaluating the impact of this advantage over energy-integrating CT (ECT) for estimation of morphological radiomics features in lung lesions. MATERIALS AND METHODS: A dynamic nutrient-access-based stochastic model was utilized to generate three distinct morphologies for lung lesions. The lesions were inserted into the lung parenchyma of an anthropomorphic phantom (XCAT - 50th percentile BMI) at 50, 70, and 90 mm from isocenter. The phantom was virtually imaged with an imaging simulator (DukeSim) modeling a Si-PCCT and a conventional ECT system using varying imaging conditions (dose, reconstruction kernel, and pixel size). The imaged lesions were segmented using a commercial segmentation tool (AutoContour, Advantage Workstation Server 3.2, GE Healthcare) followed by extraction of morphological radiomics features using an open-source radiomics package (pyradiomics). The estimation errors for both systems were computed as percent differences from corresponding feature values estimated for the ground-truth lesions. RESULTS: Compared to ECT, the mean estimation error was lower for Si-PCCT (independent features: 35.9% vs. 54.0%, all features: 54.5% vs. 68.1%) with statistically significant reductions in errors for 8/14 features. For both systems, the estimation accuracy was minimally affected by dose and distance from the isocenter while reconstruction kernel and pixel size were observed to have a relatively stronger effect. CONCLUSION: For all lesions and imaging conditions considered, Si-PCCT exhibited improved estimation accuracy for morphological radiomics features over a conventional ECT system, demonstrating the potential of this technology for improved quantitative imaging.

Early and midterm patency of arteriovenous fistula for hemodialysis access using different techniques and their advantages and disadvantages.

This descriptive retrospective study was done to observe the different techniques of arteriovenous fistula creation for advantages and disadvantages, complications, and early and midterm patency. Fifty-three arteriovenous fistulas were created from September 2018 to August 2020 using four different techniques. Radio-cephalic arteriovenous fistula was usually the first option. Other techniques like brachio-cephalic arteriovenous fistula, radio-basilic arteriovenous fistula, and brachio-basilic arteriovenous fistula were used when the radio-cephalic fistula had thrombosed or could not be constructed due to small-sized cephalic vein in the forearm. The majority of patients (41 (77.35%)) underwent radio-cephalic fistula creation. Early patency was 38 (92.7%) in the radio-cephalic technique whereas it was 12 (100%) in the radio-basilic, brachio-cephalic, and brachio-basilic techniques combined. The midterm patency was 32 (78%) in the radio-cephalic technique, 5 (83%) in the brachio-cephalic technique, 3 (75%) in the radio-basilic technique, and 1 (50%) in the brachio-basilic technique. Radio-basilic and brachio-cephalic are alternative techniques for fistula creation after radio-cephalic depending upon the size of the basilic vein in the forearm or cephalic vein in the cubital fossa or arm. The radio-basilic technique may have advantages over the brachio-cephalic technique which need to be further evaluated. Proximal fistulas like brachio-basilic and brachio-cephalic are more commonly associated with limb edema.

Dose coefficients for organ dosimetry in tomosynthesis imaging of adults and pediatrics across diverse protocols.

PURPOSE: The gold-standard method for estimation of patient-specific organ doses in digital tomosynthesis (DT) requires protocol-specific Monte Carlo (MC) simulations of radiation transport in anatomically accurate computational phantoms. Although accurate, MC simulations are computationally expensive, leading to a turnaround time in the order of core hours for simulating a single exam. This limits their clinical utility. The purpose of this study is to overcome this limitation by utilizing patient- and protocol-specific MC simulations to develop a comprehensive database of air-kerma-normalized organ dose coefficients for a virtual population of adult and pediatric patient models over an expanded set of exam protocols in DT for retrospective and prospective estimation of radiation dose in clinical tomosynthesis. MATERIALS AND METHODS: A clinically representative virtual population of 14 patient models was used, with pediatric models (M and F) at ages 1, 5, 10, and 15 and adult patient models (M and F) with body mass index (BMIs) at 10th, 50th, and 90th percentiles of the US population. A graphics processing unit (GPU)-based MC simulation framework was used to simulate organ doses in the patient models, incorporating the scanner-specific configuration of a clinical DT system (VolumeRad, GE Healthcare, Waukesha, WI, USA) and an expanded set of exam protocols, including 21 distinct acquisition techniques for imaging a variety of anatomical regions (head and neck, thorax, spine, abdomen, and knee). Organ dose coefficients (hn ) were estimated by normalizing organ dose estimates to air kerma at 70 cm (X70cm ) from the source in the scout view. The corresponding coefficients for projection radiography were approximated using organ doses estimated for the scout view. The organ dose coefficients were further used to compute air-kerma-normalized patient-specific effective dose coefficients (Kn ) for all combinations of patients and protocols, and a comparative analysis examining the variation of radiation burden across sex, age, and exam protocols in DT, and with projection radiography was performed. RESULTS: The database of organ dose coefficients (hn ) containing 294 distinct combinations of patients and exam protocols was developed and made publicly available. The values of Kn were observed to produce estimates of effective dose in agreement with prior studies and consistent with magnitudes expected for pediatric and adult patients across the different exam protocols, with head and neck regions exhibiting relatively lower and thorax and C-spine (apsc, apcs) regions relatively higher magnitudes. The ratios (r = Kn /Kn ,rad ) quantifying the differences air-kerma-normalized patient-specific effective doses between DT and projection radiography were centered around 1.0 for all exam protocols, with the exception of protocols covering the knee region (pawk, patk). CONCLUSIONS: This study developed a database of organ dose coefficients for a virtual population of 14 adult and pediatric XCAT patient models over a set of 21 exam protocols in DT. Using empirical measurements of air kerma in the clinic, these organ dose coefficients enable practical retrospective and prospective patient-specific radiation dosimetry. The computation of air-kerma-normalized patient-specific effective doses further enables the comparison of radiation burden to the patient populations between protocols and between imaging modalities (e.g., DT and projection radiography), as presented in this study.

A GPU-accelerated framework for individualized estimation of organ doses in digital tomosynthesis.

PURPOSE: Estimation of organ doses in digital tomosynthesis (DT) is challenging due to the lack of existing tools that accurately and flexibly model protocol- and view-specific collimations and motion trajectories of the source and detector for a variety of exam protocols, and the computational inefficiencies of conducting MC simulations. The purpose of this study was to overcome these limitations by developing and benchmarking a GPU-accelerated MC simulation framework compatible with patient-specific computational phantoms for individualized estimation of organ doses in DT. MATERIALS AND METHODS: The framework for individualized estimation of dose in DT was developed as a two-step workflow: (1) a custom MATLAB code that accepts a patient-specific computational phantom and exam description (organ markers for defining the extremities of the anatomical region of interest, tube voltage, source-to-image distance, angular sweep range, number of projection views, and the pivot point to image distance - PPID) to compute the field of views (FOVs) for a clinical DT system, and (2) a MC tool (developed using MC-GPU) modeling the configuration of a clinical DT system to estimate organ doses based on the computed FOVs. Using this framework, we estimated organ doses for 28 radiosensitive organs in an adult reference patient model (M; 30 years) imaged using a commercial DT system (VolumeRad, GE Healthcare, Waukesha, WI). The estimates were benchmarked against values from a comparable organ dose estimation framework (reference dataset developed by the Advanced Laboratory for Radiation Dosimetry Studies at University of Florida) for a posterior-anterior chest exam. The resulting differences were quantified as percent relative errors and analyzed to identify any potential sources of bias and uncertainties. The timing performance (run duration in seconds) of the framework was also quantified for the same simulation to gauge the feasibility of the workflow for time-constrained clinical applications. RESULTS: The organ dose estimates from the developed framework showed a close agreement with the reference dataset, with percent relative errors ranging from -6.9% to 5.0% and a mean absolute percent difference of 1.7% over all radiosensitive organs, with the exception of testes and eye lens, for which the percent relative errors were higher at -18.9% and -27.6%, respectively, due to their relative positioning outside the primary irradiation field, leading to fewer photons depositing energy and consequently higher errors in estimated organ doses. The run duration for the same simulation was 916.3 s, representing a substantial improvement in performance over existing nonparallelized MC tools. CONCLUSIONS: This study successfully developed and benchmarked a GPU-accelerated framework compatible with patient-specific anthropomorphic computational phantoms for accurate individualized estimation of organ doses in DT. By enabling patient-specific estimation of organ doses, this framework can aid clinicians and researchers by providing them with tools essential for tracking the radiation burden to patients for dose monitoring purposes and identifying the trends and relationships in organ doses for a patient population to optimize existing and develop new exam protocols.

Corrections to "iPhantom: A Framework for Automated Creation of Individualized Computational Phantoms and its Application to CT Organ Dosimetry".

In [1], the dose estimation accuracy using the alternative baseline method under modulated tube current was not correctly calculated due to an unintentional simulation error.

Ulnar-Basilic Arteriovenous Fistula for Hemodialysis Access: Utility as the "Second Procedure" after Radio Cephalic Fistula.

Objectives: As per standard guidelines, the recommended order of arteriovenous fistula (AVF) creation for hemodialysis (HD) access is radiocephalic (RC), followed by proximal elbow fistulas and arteriovenous graft. Although ulnar-basilic (UB) fistula has been an alternative to RC-AVF, still this procedure searches clear recommendations. We present here our experience on UB-AVF as the preferred "second procedure" instead of proximal fistula after the RC-AVF. Methods: Forty-two UB-AVF were created in nonfeasible and failed RC-AVF cases between 2016 and 2018. They were reviewed retrospectively and outcomes were compared with 480 RC-AVF constructed within the same period. Results: The primary patency at 18 months was 73.8%, 69.6% and mean maturation time was 33.7±6.6 days, 32.1±4.7 days for UB-AVF and RC-AVF respectively (p>0.05). Conclusion: Our altered order of preference enabled us to create all the first-time fistula in the distal forearm, providing all the advantages of distal fistula like RC-AVF and avoiding proximal fistula, improved patient convenience and short-term benefit. In an inference that may be used for references and needs support from a larger sample and longer duration study from other centers, UB-AVF may be considered as the second option after RC-AVF depending on the clinical scenario.

A GPU-accelerated framework for rapid estimation of scanner-specific scatter in CT for virtual imaging trials.

Virtual imaging trials (VITs), defined as the process of conducting clinical imaging trials using computer simulations, offer a time- and cost-effective alternative to traditional imaging trials for CT. The clinical potential of VITs hinges on the realism of simulations modeling the image acquisition process, where the accurate scanner-specific simulation of scatter in a time-feasible manner poses a particular challenge. To meet this need, this study proposes, develops, and validates a rapid scatter estimation framework, based on GPU-accelerated Monte Carlo (MC) simulations and denoising methods, for estimating scatter in single source, dual-source, and photon-counting CT. A CT simulator was developed to incorporate parametric models for an anti-scatter grid and a curved energy integrating detector with an energy-dependent response. The scatter estimates from the simulator were validated using physical measurements acquired on a clinical CT system using the standard single-blocker method. The MC simulator was further extended to incorporate a pre-validated model for a PCD and an additional source-detector pair to model cross scatter in dual-source configurations. To estimate scatter with desirable levels of statistical noise using a manageable computational load, two denoising methods using a (1) convolutional neural network and an (2) optimized Gaussian filter were further deployed. The viability of this framework for clinical VITs was assessed by integrating it with a scanner-specific ray-tracer program to simulate images for an image quality (Mercury) and an anthropomorphic phantom (XCAT). The simulated scatter-to-primary ratios agreed with physical measurements within 4.4% ± 10.8% across all projection angles and kVs. The differences of ∼121 HU between images with and without scatter, signifying the importance of scatter for simulating clinical images. The denoising methods preserved the magnitudes and trends observed in the reference scatter distributions, with an averaged rRMSE value of 0.91 and 0.97 for the two methods, respectively. The execution time of ∼30 s for simulating scatter in a single projection with a desirable level of statistical noise indicates a major improvement in performance, making our tool an eligible candidate for conducting extensive VITs spanning multiple patients and scan protocols.

A scanner-specific framework for simulating CT images with tube current modulation.

Although tube current modulation (TCM) is routinely implemented in modern computed tomography (CT) scans, no existing CT simulator is capable of generating realistic images with TCM. The goal of this study was to develop such a framework to (1) facilitate patient-specific optimization of TCM parameters and (2) enable future virtual imaging trials (VITs) with more clinically realistic image quality and x-ray flux distributions. The framework was created by developing a TCM module and integrating it with an existing CT simulator (DukeSim). The developed module utilizes scanner-calibrated TCM parameters and two localizer radiographs to compute the mAs for each simulated CT projection. This simulation pipeline was validated in two parts. First, DukeSim was validated in the context of a commercial scanner with TCM (SOMATOM Force, Siemens Healthineers) by imaging a physical CT phantom (Mercury, Sun Nuclear) and its computational analogue. Second, the TCM module was validated by imaging a computational anthropomorphic phantom (ATOM, CIRS) using DukeSim with real and module-generated TCM profiles. The validation demonstrated DukeSim's realism in terms of noise magnitude, noise texture, spatial resolution, and image contrast (with average differences of 0.38%, 6.31%, 0.43%, and -9 HU, respectively). It also demonstrated the TCM module's realism in terms of projection-level mAs and resulting noise magnitude (2.86% and -2.60%, respectively). Finally, the framework was applied to a pilot VIT simulating images of three computational anthropomorphic phantoms (XCAT, with body mass indices (BMIs) of 24.3, 28.2, and 33.0) under five different TCM settings. The optimal TCM for each phantom was characterized based on various criteria, such as minimizing mAs or maximizing image quality. 'Very Weak' TCM minimized noise for the 24.3 BMI phantom, while 'Very Strong' TCM minimized noise for the 33.0 BMI phantom. This illustrates the utility of the developed framework for future optimization studies of TCM parameters and, more broadly, large-scale VITs with scanner-specific TCM.

iPhantom: A Framework for Automated Creation of Individualized Computational Phantoms and Its Application to CT Organ Dosimetry.

OBJECTIVE: This study aims to develop and validate a novel framework, iPhantom, for automated creation of patient-specific phantoms or "digital-twins (DT)" using patient medical images. The framework is applied to assess radiation dose to radiosensitive organs in CT imaging of individual patients. METHOD: Given a volume of patient CT images, iPhantom segments selected anchor organs and structures (e.g., liver, bones, pancreas) using a learning-based model developed for multi-organ CT segmentation. Organs which are challenging to segment (e.g., intestines) are incorporated from a matched phantom template, using a diffeomorphic registration model developed for multi-organ phantom-voxels. The resulting digital-twin phantoms are used to assess organ doses during routine CT exams. RESULT: iPhantom was validated on both with a set of XCAT digital phantoms (n = 50) and an independent clinical dataset (n = 10) with similar accuracy. iPhantom precisely predicted all organ locations yielding Dice Similarity Coefficients (DSC) 0.6 - 1 for anchor organs and DSC of 0.3-0.9 for all other organs. iPhantom showed <10% errors in estimated radiation dose for the majority of organs, which was notably superior to the state-of-the-art baseline method (20-35% dose errors). CONCLUSION: iPhantom enables automated and accurate creation of patient-specific phantoms and, for the first time, provides sufficient and automated patient-specific dose estimates for CT dosimetry. SIGNIFICANCE: The new framework brings the creation and application of CHPs (computational human phantoms) to the level of individual CHPs through automation, achieving wide and precise organ localization, paving the way for clinical monitoring, personalized optimization, and large-scale research.

Bone remineralization of lytic lesions in multiple myeloma - The Arkansas experience.

Multiple myeloma (MM) patients frequently present with extensive osteolytic bone lesions. However, the impact of myeloma treatment on focal lytic lesion remineralization has not been extensively studied. In this study, the effect of anti-myeloma treatment on the extent of bone remineralization was examined and potential mediators identified. Newly diagnosed MM patients enrolled in the Total Therapy 4 and 5 (TT4; n = 231, TT5; n = 64) protocols were longitudinally evaluated for changes in radiological parameters for a median of 6.1 years. Bone remineralization was defined as a sclerotic CT change within the lytic lesion and quantified as a percentage of remineralization, using the initial lesion size as a reference. Such changes were correlated to clinical and biochemical parameters, and the gene expression profile of bone marrow biopsy. Overall, remineralization occurred in 72% of patients (213/295). Of those patients that experienced remineralization, 36% (107/295) achieved at least 25% of bone remineralization. Patients with high-risk disease defined by gene expression profile signature (GEP70 ≥ 0.66) experienced significant remineralization compared to low-risk MM. Female patients were also more likely to experience bone remineralization and in a shorter median time (2.0 vs. 3.3 y). Factors such as serum alkaline phosphatase along with high levels of RUNX2 and SOX4 gene expression correlated with increasing extent of bone remineralization. This analysis demonstrated significant remineralization of lytic lesions in MM patients treated on TT clinical trials. While the underlying mechanism remains elusive these findings support the hypothesis that patient baseline bone-related factors play a fundamental role in the skeletal repair of bone lesions in MM that provide new opportunities for improving patient outcomes.

The Unique Nature of Depression and Anxiety among College Students with Adverse Childhood Experiences.

It is well established that adverse childhood experiences (ACEs) contribute to the development of mental disorders in adulthood. However, less is known about how childhood trauma impacts the mind and the body, whether the resulting mental disorders have different characteristics than those occurring without these antecedent conditions, and if treatment modalities need to reflect the unique nature of mental disorders rooted in trauma. Survey and biomarker data were gathered from a sample of college students (n = 93) to explore the relationship between childhood trauma and mental health. We examine how neuroimmune systems (inflammation and neuroplasticity) relate to depression and anxiety and whether these associations vary for those with and without a history of childhood trauma. Findings reveal that students with 4 or more ACEs are more likely to have depression and anxiety than students without these experiences. In addition, we find that inflammation (CRP) and neuronal health (BDNF) are associated with mental health disorders among students with four or more ACEs, but not for students without this history. These findings suggest that mental disorders associated with four or more ACEs may be uniquely tied to physiological processes, and consequently, warrant tailored treatments. The implications for mental health intervention include, 1) screening for childhood trauma, inflammation, and neuronal health and 2) referral to treatments which are theoretically and empirically tied to the root causes of mental disorders rather than those designed merely to suppress their symptoms.

Lower Extremity Marjolin's Ulcer Reconstruction With Free Anterolateral Thigh Flap: A Case Series of 11 Patients.

Background Marjolin's ulcer (MU) of lower extremities usually presents with scar contracture and functional disability. They often follow an aggressive course and poor outcome, and require early radical removal. Split-thickness skin grafts, local flaps, or amputation are commonly practiced surgical options for MU. Though free flaps are gaining popularity for various oncoplastic reconstruction, they are not frequently used for MU. A free anterolateral thigh (ALT) flap may have a beneficial role as it provides simultaneous coverage for a large defect after radical tumor and scar excision. Methods Between January 2015 and December 2018, 11 patients with lower limb MU reconstructed with free ALT flap were reviewed retrospectively for the surgical procedure, recurrences, and functional outcomes. Results Mean dimensions of the defect and flaps were 8 cm × 6 cm and 18.91 cm × 11 cm, respectively, and total flap coverage was obtained in nine cases. Marginal flap loss was noted in one and residual contracture in two cases. Functional improvement of the limb was achieved in all cases. Recurrence or disease-related mortality was not seen in any patient after a mean follow-up of 35.82 months. Conclusions Free ALT flap reconstruction of MU of extremity facilitates most radical tumor and scar-contracture removal and thus reduces the chances of re-ulceration. It facilitates local radiotherapy protocol with the provision of immediate durable coverage. Thus, it has a beneficial role other than a secondary reconstructive procedure. Moreover, an added benefit may be obtained with a "flow-through' flap" to avoid amputation and improve functional outcomes.

Virtual clinical trial for quantifying the effects of beam collimation and pitch on image quality in computed tomography.

Purpose: To utilize a virtual clinical trial (VCT) construct to investigate the effects of beam collimation and pitch on image quality (IQ) in computed tomography (CT) under different respiratory and cardiac motion rates. Approach: A computational human model [extended cardiac-torso (XCAT) phantom] with added lung lesions was used to simulate seven different rates of cardiac and respiratory motions. A validated CT simulator (DukeSim) was used in this study. A supplemental validation was done to ensure the accuracy of DukeSim across different pitches and beam collimations. Each XCAT phantom was imaged using the CT simulator at multiple pitches (0.5 to 1.5) and beam collimations (19.2 to 57.6 mm) at a constant dose level. The images were compared against the ground truth using three task-generic IQ metrics in the lungs. Additionally, the bias and variability in radiomics (morphological) feature measurements were quantified for task-specific lung lesion quantification across the studied imaging conditions. Results: All task-generic metrics degraded by 1.6% to 13.3% with increasing pitch. When imaged with motion, increasing pitch reduced motion artifacts. The IQ slightly degraded (1.3%) with changes in the studied beam collimations. Patient motion exhibited negative effects (within 7%) on the IQ. Among all features across all imaging conditions studies, compactness2 and elongation showed the largest ( - 26.5 % , 7.8%) and smallest ( - 0.8 % , 2.7%) relative bias and variability. The radiomics results were robust across the motion profiles studied. Conclusions: While high pitch and large beam collimations can negatively affect the quality of CT images, they are desirable for fast imaging. Further, our results showed no major adverse effects in morphology quantification of lung lesions with the increase in pitch or beam collimation. VCTs, such as the one demonstrated in this study, represent a viable methodology for experiments in CT.

Adverse childhood experiences and neuroinflammatory biomarkers-The role of sex.

Despite the growing interest in adverse childhood experiences and biomarkers, less attention has been paid to multiple biomarkers as representing interrelated systems among college students. Guided by the neuroinflammatory pathway hypothesis, the current project takes the initial step in examining the link between three types of childhood adversity and biomarkers of neuroplasticity (brain-derived neurotropic factor [BDNF]) and low-grade inflammation (C-reactive protein [CRP]) in an overarching model and whether this link may differ in men and women. Undergraduate students (n = 85) were recruited through multiple departments from a state university. The participants responded to the detailed online survey questionnaire on childhood adversity and provided one blood sample via venous blood draw. Given that CRP and BDNF represent two interrelated systems, structural equation models were considered the most suitable for the analyses. The findings partially support neural and inflammatory pathways, such that childhood adversity and particularly family dysfunction have a significant positive effect on BDNF (b = 30.41, p < .01). The link between family dysfunction and CRP was stronger in female students (b = 0.57, p < .05). Results suggest that interventions for college students with family dysfunctions may need to target different physiological and behavioral outcomes for male and female students.

A real-time Monte Carlo tool for individualized dose estimations in clinical CT.

The increasing awareness of the adverse effects associated with radiation exposure in computed tomography (CT) has necessesitated the quantification of dose delivered to patients for better risk assessment in the clinic. The current methods for dose quantification used in the clinic are approximations, lacking realistic models for the irradiation conditions utilized in the scan and the anatomy of the patient being imaged, which limits their relevance for a particular patient. The established gold-standard technique for individualized dose quantification uses Monte Carlo (MC) simulations to obtain patient-specific estimates of organ dose in anatomically realistic computational phantoms to provide patient-specific estimates of organ dose. Although accurate, MC simulations are computationally expensive, which limits their utility for time-constrained applications in the clinic. To overcome these shortcomings, a real-time GPU-based MC tool based on FDA's MC-GPU framework was developed for patient and scanner-specific dosimetry in the clinic. The tool was validated against (1) AAPM's TG-195 reference datasets and (2) physical measurements of dose acquired using TLD chips in adult and pediatric anthropomorphic phantoms. To demonstrate its utility towards providing individualized dose estimates, it was integrated with an automatic segmentation method for generating patient-specific models, which were then used to estimate patient- and scanner-specific organ doses for a select population of 50 adult patients using a clinically relevant CT protocol. The organ dose estimates were compared to corresponding dose estimates from a previously validated MC method based on Penelope. The dose estimates from our MC tool agreed within 5% for all organs (except thyroid) tabulated by TG-195 and within 10% for all TLD locations in the adult and pediactric phantoms, across all validation cases. Compared against Penelope, the organ dose estimates agreed within 3% on average for all organs in the patient population study. The average run duration for each patient was estimated at 23.79 s, representing a significant speedup (~700×) over existing non-parallelized MC methods. The accuracy of dose estimates combined with a significant improvement in execution times suggests a feasible solution utilizing the proposed MC tool for real-time individualized dosimetry in the clinic.