Establishment of a sequential dual tracer 18 F-NaF/18 F-FDG PET protocol for imaging the equine foot.

The combination of 18 F-Sodium Fluoride (18 F-NaF) and 18 F-FluoroDeoxyGlucose (18 F-FDG) for positron emission tomography (PET) imaging of the equine foot is appealing for detection of both osseous and soft tissue lesions in a single scan. As the combination of tracers could lead to a loss of information, a sequential approach, consisting in imaging with one tracer prior to injecting the second tracer, might be valuable. The goals of this prospective, methods comparison, exploratory study were to establish the order of tracer injection and timing for imaging. Six research horses were imaged under general anesthesia with 18 F-NaF PET, 18 F-FDG PET, dual 18 F-NaF/18 F-FDG PET, and CT. Proper uptake could be identified in tendon lesions as early as 10 min after 18F-FDG injection. Bone uptake was limited when 18F-NaF was injected under general anesthesia, even at 1 h after injection, when compared with 18 F-NaF injection prior to anesthesia. The sensitivity and specificity of the dual tracer scans were 0.77 (0.63 to 0.86) and 0.98 (0.96 to 0.99) respectively, to assess 18 F-NaF uptake and 0.5 (0.28 to 0.72) and 0.98 (0.95 to 0.99), respectively, for 18F-FDG uptake. These results suggest that the sequential dual tracer approach is a pertinent technique to optimize the PET data gained from a single anesthetic episode. Based on dynamics of tracer uptake, the optimal protocol consists in injecting 18F-NaF prior to anesthesia, acquire 18F-NaF data then inject 18F-FDG and start acquisition of dual tracer PET data 10 min later. This protocol should be further validated in a larger clinical study.

Imaging the fetal nonhuman primate brain with SV2A positron emission tomography (PET).

PURPOSE: Exploring synaptic density changes during brain growth is crucial to understanding brain development. Previous studies in nonhuman primates report a rapid increase in synapse number between the late gestational period and the early neonatal period, such that synaptic density approaches adult levels by birth. Prenatal synaptic development may have an enduring impact on postnatal brain development, but precisely how synaptic density changes in utero are unknown because current methods to quantify synaptic density are invasive and require post-mortem brain tissue. METHODS: We used synaptic vesicle glycoprotein 2A (SV2A) positron emission tomography (PET) radioligands [11C]UCB-J and [18F]Syn-VesT-1 to conduct the first assessment of synaptic density in the developing fetal brain in gravid rhesus monkeys. Eight pregnant monkeys were scanned twice during the third trimester at two imaging sites. Fetal post-mortem samples were collected near term in a subset of subjects to quantify SV2A density by Western blot. RESULTS: Image-derived fetal brain SV2A measures increased during the third trimester. SV2A concentrations were greater in subcortical regions than in cortical regions at both gestational ages. Near term, SV2A density was higher in primary motor and visual areas than respective associative regions. Post-mortem quantification of SV2A density was significantly correlated with regional SV2A PET measures. CONCLUSION: While further study is needed to determine the exact relationship of SV2A and synaptic density, the imaging paradigm developed in the current study allows for the effective in vivo study of SV2A development in the fetal brain.

Gynecologist Supply Deserts Across the VA and in the Community.

BACKGROUND: The Veterans Health Administration (VA) refers patients to community providers for specialty services not available on-site. However, community-level specialist shortages may impede access to care. OBJECTIVE: Compare gynecologist supply in veterans' county of residence versus at their VA site. DESIGN: We identified women veteran VA patients from fiscal year (FY) 2017 administrative data and assessed availability of a VA gynecologist within 50 miles (hereafter called "local") of veterans' VA homesites (per national VA organizational survey data). For the same cohort, we then assessed community-level gynecologist availability; counties with < 2 gynecologists/10,000 women (per the Area Health Resource File) were "inadequate-supply" counties. We examined the proportion of women veterans with local VA gynecologist availability in counties with inadequate versus adequate gynecologist supply, stratified by individual and VA homesite characteristics. Chi-square tests assessed statistical differences. PARTICIPANTS: All women veteran FY2017 VA primary care users nationally. MAIN MEASURES: Availability of a VA gynecologist within 50 miles of a veteran's VA homesite; county-level "inadequate-supply" of gynecologists. KEY RESULTS: Among 407,482 women, 9% were in gynecologist supply deserts (i.e., lacking local VA gynecologist and living in an inadequate-supply county). The sub-populations with the highest proportions in gynecologist supply deserts were rural residents (24%), those who got their primary care at non-VAMC satellite clinics (13%), those who got their care at a site without a women's clinic (13%), and those with American Indian or Alaska Native (12%), or white (12%) race. Among those in inadequate-supply counties, 59.9% had gynecologists at their local VA; however, 40.1% lacked a local VA gynecologist. CONCLUSIONS: Most veterans living in inadequate-supply counties had local VA gynecology care, reflecting VA's critical role as a safety net provider. However, for those in gynecologist supply deserts, expanded transportation options, modified staffing models, or tele-gynecology hubs may offer solutions to extend VA gynecology capacity.

Autoerotic Death by Electrocution: An Atypical Case Study.

ABSTRACT: Autoerotic death is defined as an accidental death that occurs when some type of apparatus is used to enhance sexual stimulation and causes an unintended death. We present the case of an atypical autoerotic death of a 23-year-old man found deceased in a bathroom. An electrical cord with a standard wall plug on one end and exposed wires twisted into loops on the other end was on the floor near his body. Minute black burns were present on each nipple. The outlet was protected by a ground fault circuit interrupter that was demonstrated to be in working order. An electrical consultant concluded that the cause of death could not be electrocution. Ground fault circuit interrupters work by detecting differences in current within a circuit. If a ground fault occurs, the circuit is broken to prevent a fatal electrocution. In the present case, the ground fault circuit interrupter did not shut off because the decedent had wired himself in parallel with the circuit. This, with the other scene findings, indicated this to be a case of atypical autoerotic death. Autoerotic deaths by means other than asphyxiation are rare. This case serves to illustrate the circumstances of an atypical autoerotic death by means of electrocution.

Retaining VA Women's Health Primary Care Providers: Work Setting Matters.

BACKGROUND: When an experienced provider opts to leave a healthcare workforce (attrition), there are significant costs, both direct and indirect. Turnover of healthcare providers is underreported and understudied, despite evidence that it negatively impacts care delivery and negatively impacts working conditions for remaining providers. In the Veterans Affairs (VA) healthcare system, attrition of women's health primary care providers (WH-PCPs) threatens a specially trained workforce; it is unknown what factors contribute to, or protect against, their attrition. OBJECTIVE: Based on evidence that clinic environment, adequate support resources, and workload affect provider burnout and intent to leave, we explored if such clinic characteristics predict attrition of WH-PCPs in the VA, to identify protective factors. DESIGN: This analysis drew on two waves of existing national VA survey data to examine predictors of WH-PCP attrition, via logistic regression. PARTICIPANTS: All 2,259 providers from 140 facilities VA-wide who were WH-PCPs on September 30, 2016. MAIN MEASURES: The dependent variable was WH-PCP attrition in the following year. Candidate predictors were clinic environment (working in: a comprehensive women's health center, a limited women's health clinic, a general primary care clinic, or multiple clinic environments), availability of co-located specialty support resources (mental health, social work, clinical pharmacy), provider characteristics (gender, professional degree), and clinic workload (clinic sessions per week). KEY RESULTS: Working exclusively in a comprehensive women's health center uniquely predicted significantly lower risk of WH-PCP attrition (adjusted odds ratio 0.40; CI 0.19-0.86). CONCLUSIONS: A comprehensive women's health center clinical context may promote retention of this specially trained primary care workforce. Exploring potential mechanisms-e.g., shared mission, appropriate support to meet patients' needs, or a cohesive team environment-may inform broader efforts to retain front-line providers.

Pork Products Have Digestible Indispensable Amino Acid Scores (DIAAS) That Are Greater Than 100 When Determined in Pigs, but Processing Does Not Always Increase DIAAS.

BACKGROUND: Raw meat contains all indispensable amino acids (IAAs), but before human consumption, meat usually undergoes some degree of processing. Processing affects the 3-dimensional structure of proteins, which may affect amino acid (AA) digestibility and, therefore, overall protein quality. OBJECTIVES: The experiment aimed at determining digestible indispensable amino acid scores (DIAAS) for pork products, and to test the hypothesis that processing increases DIAAS. METHODS: Ten ileal cannulated gilts (body weight: 26.63 ± 1.62 kg) were randomly allotted to a 10 × 10 Latin square design with ten 7-d periods. Ileal digesta were collected for 9 h on days 6 and 7 of each period. Nine diets contained a single pork product (i.e., raw belly, smoked bacon, smoked-cooked bacon, non-cured ham, alternatively cured ham, conventionally cured ham, and loins heated to 63°C, 68°C, or 72°C) as the sole source of AAs. A nitrogen-free diet was formulated to determine basal endogenous losses of AAs, which enabled calculation of standardized ileal digestibility (SID) of AAs. DIAAS were subsequently calculated according to the FAO. RESULTS: All pork products had DIAAS >100 (as-is basis). Loin heated to 63°C had the greatest (P < 0.05) DIAAS for children 6 mo to 3 y and smoked-cooked bacon had the greatest (P < 0.05) DIAAS for children older than 3 y, adolescents, and adults. Raw belly, smoked bacon, and loins heated to 68°C and 72°C had a reduced (P < 0.05) DIAAS for both reference patterns compared with other proteins. Alternatively cured ham had greater (P < 0.05) DIAAS when compared with non-cured ham and conventionally cured ham. CONCLUSIONS: Bacon, ham, and loin are excellent proteins with DIAAS >100, and processing may sometimes, but not always, increase DIAAS.

Most meat products have digestible indispensable amino acid scores that are greater than 100, but processing may increase or reduce protein quality.

An experiment was conducted to test the hypothesis that meat products have digestible indispensable amino acid scores (DIAAS) >100 and that various processing methods will increase standardised ileal digestibility (SID) of amino acids (AA) and DIAAS. Nine ileal-cannulated gilts were randomly allotted to a 9 × 8 Youden square design with nine diets and eight 7-d periods. Values for SID of AA and DIAAS for two reference patterns were calculated for salami, bologna, beef jerky, raw ground beef, cooked ground beef and ribeye roast heated to 56, 64 or 72°C. The SID of most AA was not different among salami, bologna, beef jerky and cooked ground beef, but was less (P < 0·05) than the values for raw ground beef. The SID of AA for 56°C ribeye roast was not different from the values for raw ground beef and 72°C ribeye roast, but greater (P < 0·05) than those for 64°C ribeye roast. For older children, adolescents and adults, the DIAAS for all proteins, except cooked ground beef, were >100 and bologna and 64°C ribeye roast had the greatest (P < 0·05) DIAAS. The limiting AA for this age group were sulphur AA (beef jerky), leucine (bologna, raw ground beef and cooked ground beef) and valine (salami and the three ribeye roasts). In conclusion, meat products generally provide high-quality protein with DIAAS >100 regardless of processing. However, overcooking meat may reduce AA digestibility and DIAAS.

Machine Learning in PET: from Photon Detection to Quantitative Image Reconstruction.

Machine learning has found unique applications in nuclear medicine from photon detection to quantitative image reconstruction. While there have been impressive strides in detector development for time-of-flight positron emission tomography, most detectors still make use of simple signal processing methods to extract the time and position information from the detector signals. Now with the availability of fast waveform digitizers, machine learning techniques have been applied to estimate the position and arrival time of high-energy photons. In quantitative image reconstruction, machine learning has been used to estimate various corrections factors, including scattered events and attenuation images, as well as to reduce statistical noise in reconstructed images. Here machine learning either provides a faster alternative to an existing time-consuming computation, such as in the case of scatter estimation, or creates a data-driven approach to map an implicitly defined function, such as in the case of estimating the attenuation map for PET/MR scans. In this article, we will review the abovementioned applications of machine learning in nuclear medicine.

Characterization of Large-Area SiPM Array for PET Applications.

The performance of an 8 × 8 array of 6.0 × 6.0 mm2 (active area) SiPMs was evaluated for PET applications using crystal arrays with different pitch sizes (3.4 mm, 1.5 mm, 1.35 mm and 1.2 mm) and custom designed five-channel front-end readout electronics (four channels for position information and one channel for timing information). The total area of this SiPM array is 57.4 × 57.4 mm2, and the pitch size is 7.2 mm. It was fabricated using enhanced blue sensitivity SiPMs (MicroFB-60035-SMT) with peak spectral sensitivity at 420 nm. The performance of the SiPM array was characterized by measuring flood histogram decoding quality, energy resolution, timing resolution and saturation at several bias voltages (from 25.0 V to 30.0 V in 0.5 V intervals) and two different temperatures (5 °C and 20 °C). Results show that the best flood histogram was obtained at a bias voltage of 28.0 V and 5 °C and an array of polished LSO crystals with a pitch as small as 1.2 mm can be resolved. No saturation was observed up to a bias voltage of 29.5 V during the experiments, due to adequate light sharing between SiPMs. Energy resolution and timing resolution at 5 °C ranged from 12.7 ± 0.8% to 14.6 ± 1.4 % and 1.58 ± 0.13 ns to 2.50 ± 0.44 ns, for crystal array pitch sizes of 3.4 mm and 1.2 mm respectively. Superior flood histogram quality, energy resolution and timing resolution were obtained with larger crystal array pitch sizes and at lower temperature. Based on our findings, we conclude that this large-area SiPM array can serve as a suitable photodetector for high-resolution small-animal PET or dedicated human brain PET scanners.

Travel time and attrition from VHA care among women veterans: how far is too far?

BACKGROUND: Travel time, an access barrier, may contribute to attrition of women veterans from Veterans Health Administration (VHA) care. OBJECTIVE: We examined whether travel time influences attrition: (a) among women veterans overall, (b) among new versus established patients, and (c) among rural versus urban patients. RESEARCH DESIGN: This retrospective cohort study used logistic regression to estimate the association between drive time and attrition, overall and for new/established and rural/urban patients. SUBJECTS: In total, 266,301 women veteran VHA outpatients in the Fiscal year 2009. MEASURES: An "attriter" did not return for VHA care during the second through third years after her first 2009 visit (T0). Drive time (log minutes) was between the patient's residence and her regular source of VHA care. "New" patients had no VHA visits within 3 years before T0. Models included age, service-connected disability, health status, and utilization as covariates. RESULTS: Overall, longer drive times were associated with higher odds of attrition: drive time adjusted odds ratio=1.11 (99% confidence interval, 1.09-1.14). The relationship between drive time and attrition was stronger among new patients but was not modified by rurality. CONCLUSIONS: Attrition among women veterans is sensitive to longer drive time. Linking new patients to VHA services designed to reduce distance barriers (telemedicine, community-based clinics, mobile clinics) may reduce attrition among women new to VHA.

Association of lunch meat consumption with nutrient intake, diet quality and health risk factors in U.S. children and adults: NHANES 2007-2010.

BACKGROUND: Consumption of lean meat is recommended as part of healthy diet by Dietary Guidelines for Americans, 2010. Lunch meats are precooked or cured meats typically used in sandwiches and are also called as cold cuts or deli meat. OBJECTIVE: The purpose of the study was to examine the association of lunch meat consumption with nutrient intake, diet quality, and physiological measures in children (age 2-18 years; n = 5,099) and adults (age 19 years and older; n = 10,216) using a large, nationally representative database. METHODS: Lunch meat consumers were defined as those consuming any amount of lunch meat during a 24-h recall and association with nutrient intake, diet quality (Healthy Eating Index (HEI)-2010 score) and physiological measures were evaluated using the National Health and Nutrition Examination Survey (NHANES), 2007-2010. RESULTS: The lunch meat consumers (both children and adults) had higher intakes of calories, protein, calcium, potassium, sodium and saturated fat (for adults only) compared to non-consumers. Lunch meat intake was also associated with higher intake of meat/poultry/fish food group in both children and adult consumers than non-consumers. There was no difference in total HEI-2010 scores comparing lunch meat consumers and non-consumers in children or adults. However, HEI components scores for total fruit, whole fruit (children only), whole grains, dairy and total protein foods were significantly higher, and for greens & beans (adults only), seafood and plant protein, fatty acid ratio and sodium were significantly lower in children and adult lunch meat consumers compared to non-consumers. There were no significant differences in physiological measures or in the odds ratios of health related conditions between lunch meat consumers and non-consumers in children or adults. CONCLUSIONS: The results of this study may provide insight into how to better utilize lunch meats in the diets of U.S. children and adults.

Consumption of ground beef obtained from cattle that had received steroidal growth promotants does not trigger early onset of estrus in prepubertal pigs.

BACKGROUND: The earlier onset of puberty seen in young American girls has led researchers to question if a causal relation exists between dietary sources of estrogenic compounds and precocious puberty. OBJECTIVE: Using the prepubertal gilt (young female pig) as an animal model, our hypothesis is that feeding beef obtained from cattle receiving growth-promoting steroidal implants postweaning does not alter the onset of puberty or the peripubertal body composition of gilts compared with contemporaries fed nonimplanted "natural" beef or a common meat alternative, tofu. METHOD: The base diet was formulated using canola meal replacing soybean meal to reduce diet estrogenicity. Feed intake was monitored and controlled to ensure similar intake. Gilts were assigned to treatments based on dam and initial body weight (mean: 24.5 ± 3.20 kg) at 61 d of age. The negative control base diet was supplemented with daily feedings of a cooked patty from nonimplanted steers (natural), from steers that had been treated with growth promotants [100 mg trenbolone acetate and 14 mg estradiol (E2) benzoate; implanted], or cooked tofu patty. RESULTS: E2 equivalents (nanogram per kilogram, as fed as analyzed by E-Screen) of the tofu (a soy-based product) supplement were ∼570 times the natural and ∼170 times the implanted supplements. There were no observed differences across treatments in live weight gain (P = 0.90), longissimus muscle area developed at the 10th and 11th rib interface (P = 0.46), and subcutaneous fat deposition (P = 0.41) at the same location over time or in the number of days to reach estrus (P = 0.55). CONCLUSIONS: Consumption of beef from growth implanted or natural steers or tofu at levels similar to those typically consumed by humans did not impact growth or onset of estrus in these prepubertal gilts.

Mental illness and intensification of diabetes medications: an observational cohort study.

BACKGROUND: Mental health condition (MHC) comorbidity is associated with lower intensity care in multiple clinical scenarios. However, little is known about the effect of MHC upon clinicians' decisions about intensifying antiglycemic medications in diabetic patients with poor glycemic control. We examined whether delay in intensification of antiglycemic medications in response to an elevated Hemoglobin A1c (HbA1c) value is longer for patients with MHC than for those without MHC, and whether any such effect varies by specific MHC type. METHODS: In this observational study of diabetic Veterans Health Administration (VA) patients on oral antiglycemics with poor glycemic control (HbA1c ≥8) (N =52,526) identified from national VA databases, we applied Cox regression analysis to examine time to intensification of antiglycemics after an elevated HbA1c value in 2003-2004, by MHC status. RESULTS: Those with MHC were no less likely to receive intensification: adjusted Hazard Ratio [95% CI] 0.99 [0.96-1.03], 1.13 [1.04-1.23], and 1.12 [1.07-1.18] at 0-14, 15-30 and 31-180 days, respectively. However, patients with substance use disorders were less likely than those without substance use disorders to receive intensification in the first two weeks following a high HbA1c, adjusted Hazard Ratio 0.89 [0.81-0.97], controlling for sex, age, medical comorbidity, other specific MHCs, and index HbA1c value. CONCLUSIONS: For most MHCs, diabetic patients with MHC in the VA health care system do not appear to receive less aggressive antiglycemic management. However, the subgroup with substance use disorders does appear to have excess likelihood of non-intensification; interventions targeting this high risk subgroup merit attention.

Effect of cassava bioethanol by-product and crude palm oil in Brahman x Thai native yearling heifer cattle diets: I. Nutrient digestibility and growth performance.

The effects of cassava bioethanol by-product (CEP) and crude palm oil (CPO) on feed intake, nutrient digestibility, and growth performance of yearling heifers were investigated in a 150-day feeding trial. Eighteen, crossbred heifers (Brahman x Thai native) were randomly allotted according to 2 × 3 factorial arrangement. Low or high levels of CEP (15 or 30% of concentrate, LCEP, or HCEP) were basal treatments and 0, 2, and 4% CPO were daily top-dressed. Concentrate was supplemented at 1.75% of body weight (BW) and rice straw offered ad libitum. CEP level had no significance on feed intake. CPO increased roughage intake, concentrate intake, and total feed intake when expressed as %BW/d (P < 0.01) and as metabolic BW (kg(0.75)/d, P < 0.05). Intakes of dry matter (DM), organic matter (OM), and crude protein (CP) were similar (P > 0.05). Intake of fat increased with higher levels of CPO (P < 0.001). The DM, OM, CP, and EE digestibility of cattle-fed HCEP was lower than LCEP, but adding 4% CPO increased digestibility. Growth performance was similar for all diets (P > 0.05). We concluded that CEP can be used up to 30% in the diet, with or without additional fat inclusion.

Laryngeal obstruction by cervical and endolaryngeal lymphatic malformations in children: proposed staging system and review of treatment.

OBJECTIVES: We review and stage a series of congenital lymphatic malformations (LMs) that caused laryngeal obstruction according to a proposed staging system, review the treatment modalities utilized, and correlate the stage of disease with clinical outcomes and tracheotomy statuses. METHODS: We present a detailed description of the clinical presentation, management approach, and clinical outcome and tracheotomy status of a series of patients with laryngeal obstruction by LMs. A 4-part staging system (stages I to IV) for congenital LMs obstructing the larynx, based upon our clinical experience, is proposed. The patients were retrospectively reviewed and staged according to the proposed system, and clinical management and outcomes were correlated with the stage of disease. RESULTS: We identified 16 patients with laryngeal obstruction by LMs. Eighty-one percent (13 of 16) received sclerotherapy, and 50% (8 of 16) underwent operative excision or debridement. Forty percent (2 of 5) of stage I lesions, 75% (3 of 4) of stage II lesions, 100% (4 of 4) of stage III lesions, and 100% (3 of 3) of stage IV lesions were in patients who required tracheotomy. All patients who had stage I and II lesions and required tracheotomy have been decannulated, whereas only 2 of the 4 patients with stage III lesions and no patients with stage IV lesions have been successfully decannulated. CONCLUSIONS: Lymphatic malformations obstructing the larynx require a careful and often staged management approach. A proposed staging system helps to predict the need for tracheotomy and the likelihood of long-term tracheotomy dependence.

Cancer Metabolism: Fasting Reset, the Keto-Paradox and Drugs for Undoing.

In tumor cells, ketolysis "via" succinyl-CoA: 3-oxoacid-CoAtransferase (SCOT) and acetyl-CoA acetyltransferase 1 (ACAT1) is a major source of mitochondrial acetyl-CoA. Active ACAT1 tetramers stabilize by tyrosine phosphorylation, which facilitates the SCOT reaction and ketolysis. Tyrosine phosphorylation of pyruvate kinase PK M2 has the opposite effect, stabilizing inactive dimers, while pyruvate dehydrogenase (PDH), which is already inhibited by phosphorylation, is acetylated by ACAT1 and is doubly locked. This closes the glycolytic supply of acetyl-CoA. In addition, since tumor cells must synthesize fatty acids to create new membranes, they automatically turn off the degradation of fatty acids into acetyl-CoA ("via" the malonyl-CoA brake for the fatty acid carnityl transporter). Thus, inhibiting SCOT the specific ketolytic enzyme and ACAT1 should hold back tumor progression. However, tumor cells are still able to take up external acetate and convert it into acetyl-CoA in their cytosol "via" an acetyl-CoA synthetase, which feeds the lipogenic pathway; additionally, inhibiting this enzyme would make it difficult for tumor cells to form new lipid membrane and survive.

Relating18F-FDG image signal-to-noise ratio to time-of-flight noise-equivalent count rate in total-body PET using the uEXPLORER scanner.

Objective.This work assessed the relationship between image signal-to-noise ratio (SNR) and total-body noise-equivalent count rate (NECR)-for both non-time-of-flight (TOF) NECR and TOF-NECR-in a long uniform water cylinder and 14 healthy human subjects using the uEXPLORER total-body PET/CT scanner.Approach.A TOF-NEC expression was modified for list-mode PET data, and both the non-TOF NECR and TOF-NECR were compared using datasets from a long uniform water cylinder and 14 human subjects scanned up to 12 h after radiotracer injection.Main results.The TOF-NECR for the uniform water cylinder was found to be linearly proportional to the TOF-reconstructed image SNR2in the range of radioactivity concentrations studied, but not for non-TOF NECR as indicated by the reducedR2value. The results suggest that the use of TOF-NECR to estimate the count rate performance of TOF-enabled PET systems may be more appropriate for predicting the SNR of TOF-reconstructed images.Significance.Image quality in PET is commonly characterized by image SNR and, correspondingly, the NECR. While the use of NECR for predicting image quality in conventional PET systems is well-studied, the relationship between SNR and NECR has not been examined in detail in long axial field-of-view total-body PET systems, especially for human subjects. Furthermore, the current NEMA NU 2-2018 standard does not account for count rate performance gains due to TOF in the NECR evaluation. The relationship between image SNR and total-body NECR in long axial FOV PET was assessed for the first time using the uEXPLORER total-body PET/CT scanner.

Women Veterans' Attrition from the VA Health Care System.

PURPOSE: Patient attrition from the Veterans Health Administration (VA) health care system could undercut its mission to ensure care for eligible veterans. Attrition of women veterans could exacerbate their minority status and impede systemic efforts to provide high-quality care. We obtained women veterans' perspectives on why they left or continued to use VA health care. METHODS: A sampling frame of new women veteran VA patients was stratified by those who discontinued (attriters) and those who continued (non-attriters) using VA care. Semistructured interviews were conducted from 2017 to 2018. Transcribed interviews were coded for women's decision-making, contexts, and recommendations related to health care use. RESULTS: Fifty-one women veterans (25 attriters and 26 non-attriters) completed interviews. Reasons for attrition included challenging patient care experiences (e.g., provider turnover, claim processing challenges) and the availability of private health insurance. Personal experiences with VA care (e.g., gender-specific care) were impactful in women's decision to use VA. The affordability of VA care was influential for both groups to stay connected to services. More than one-third of women originally categorized as attriters described subsequently reentering or planning to reenter VA care. Suggestions to decrease attrition included increasing outreach, improving access, and continuing to tailor care delivery to women veterans' needs. CONCLUSIONS: Understanding the drivers of patients' decisions to use or not use the VA is critical for the development of strategies to improve retention of current patients and optimize health outcomes for veterans. Women veterans described complex reasons why they left or continued using VA, with cost/affordability playing an important role even in considerations of returning to VA after a long hiatus.

Medical care needs of returning veterans with PTSD: their other burden.

BACKGROUND: There has been considerable focus on the burden of mental illness (including post-traumatic stress disorder, PTSD) in returning Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veterans, but little attention to the burden of medical illness in those with PTSD. OBJECTIVES: (1) Determine whether the burden of medical illness is higher in women and men OEF/OIF veterans with PTSD than in those with No Mental Health Conditions (MHC). (2) Identify conditions common in those with PTSD. DESIGN: Cross-sectional study using existing databases (Fiscal Year 2006-2007). SETTING: Veterans Health Administration (VHA) patients nationally. PATIENTS: All 90,558 OEF/OIF veterans using VHA outpatient care nationally, categorized into strata: PTSD, Stress-Related Disorders, Other MHCs, and No MHC. MEASUREMENTS: (1) Count of medical conditions; (2) specific medical conditions (from ICD9 codes, using Agency for Health Research and Quality's Clinical Classifications software framework). MAIN RESULTS: The median number of medical conditions for women was 7.0 versus 4.5 for those with PTSD versus No MHC (p<0.001), and for men was 5.0 versus 4.0 (p<0.001). For PTSD patients, the most frequent conditions among women were lumbosacral spine disorders, headache, and lower extremity joint disorders, and among men were lumbosacral spine disorders, lower extremity joint disorders, and hearing problems. These high frequency conditions were more common in those with PTSD than in those with No MHC. CONCLUSIONS: Burden of medical illness is greater in women and men OEF/OIF veteran VHA users with PTSD than in those with No MHC. Health delivery systems serving them should align clinical program development with their medical care needs.

Pathologic effects of external-beam irradiation on human vocal folds.

OBJECTIVES: We sought to better characterize pathologic changes that occur in the human vocal fold after radiotherapy for head and neck cancer. METHODS: In a blinded, controlled study of archived tissue, we evaluated postirradiation salvage laryngectomy vocal fold tissue without evidence of malignant disease. Clinical and demographic patient data were collected. In a blinded fashion, irradiated tissue was compared to nonirradiated, benign control tissue. Histomorphometric analysis was used to assess muscle and collagen organization, superficial lamina propria (SLP) and vocal ligament thickness, vocalis muscle fiber area, collagen content, and hyaluronic acid content. Immunohistochemical analysis was used to assess the content of type I collagen, type IV collagen, vimentin, fibronectin, alpha-smooth muscle actin, matrix metalloproteinase 9, and laminin. RESULTS: Twenty irradiated vocal folds were evaluated and compared to control specimens. Collagen and muscle disorganization was noted in the irradiated specimens. The SLP and vocal ligament thicknesses and the mean muscle fiber diameters did not differ significantly. The SLP fibronectin and the vocalis muscle and SLP collagen content were significantly increased in the irradiated vocal folds, and the SLP collagen content increased significantly with time between irradiation and resection. The laminin content of irradiated vocalis muscles was significantly decreased. CONCLUSIONS: Radiotherapy results in significant vocal fold tissue changes. Having more precisely defined these changes, we plan continued investigation seeking targeted preventive and therapeutic interventions for improved vocal quality following radiotherapy.