The effect of prolonged spaceflight on cerebrospinal fluid and perivascular spaces of astronauts and cosmonauts.

Long-duration spaceflight induces changes to the brain and cerebrospinal fluid compartments and visual acuity problems known as spaceflight-associated neuro-ocular syndrome (SANS). The clinical relevance of these changes and whether they equally affect crews of different space agencies remain unknown. We used MRI to analyze the alterations occurring in the perivascular spaces (PVS) in NASA and European Space Agency astronauts and Roscosmos cosmonauts after a 6-mo spaceflight on the International Space Station (ISS). We found increased volume of basal ganglia PVS and white matter PVS (WM-PVS) after spaceflight, which was more prominent in the NASA crew than the Roscosmos crew. Moreover, both crews demonstrated a similar degree of lateral ventricle enlargement and decreased subarachnoid space at the vertex, which was correlated with WM-PVS enlargement. As all crews experienced the same environment aboard the ISS, the differences in WM-PVS enlargement may have been due to, among other factors, differences in the use of countermeasures and high-resistive exercise regimes, which can influence brain fluid redistribution. Moreover, NASA astronauts who developed SANS had greater pre- and postflight WM-PVS volumes than those unaffected. These results provide evidence for a potential link between WM-PVS fluid and SANS.

The Gene Curation Coalition: A global effort to harmonize gene-disease evidence resources.

PURPOSE: Several groups and resources provide information that pertains to the validity of gene-disease relationships used in genomic medicine and research; however, universal standards and terminologies to define the evidence base for the role of a gene in disease and a single harmonized resource were lacking. To tackle this issue, the Gene Curation Coalition (GenCC) was formed. METHODS: The GenCC drafted harmonized definitions for differing levels of gene-disease validity on the basis of existing resources, and performed a modified Delphi survey with 3 rounds to narrow the list of terms. The GenCC also developed a unified database to display curated gene-disease validity assertions from its members. RESULTS: On the basis of 241 survey responses from the genetics community, a consensus term set was chosen for grading gene-disease validity and database submissions. As of December 2021, the database contained 15,241 gene-disease assertions on 4569 unique genes from 12 submitters. When comparing submissions to the database from distinct sources, conflicts in assertions of gene-disease validity ranged from 5.3% to 13.4%. CONCLUSION: Terminology standardization, sharing of gene-disease validity classifications, and resolution of curation conflicts will facilitate collaborations across international curation efforts and in turn, improve consistency in genetic testing and variant interpretation.

Pediatric Ovarian Torsion: Should You Go With the Flow?

OBJECTIVES: Ovarian torsion (OT) is an emergency that mandates early detection and surgical detorsion to avoid catastrophic consequences of further adnexal injury. Prompt ultrasound is critical for accurate diagnosis. Traditionally, evaluation of arterial and venous flow was used as a diagnostic tool for OT, but recent radiologic research has indicated that ovarian size and size discrepancy between sides is a better diagnostic criterion. This study seeks to determine whether ovarian size discrepancy or vascular flow to the ovary is more accurate in the diagnosis of OT in the pediatric emergency population and to better describe symptoms that distinguish OT from other abdominal and pelvic pathology. METHODS: This was a retrospective, cross-sectional study evaluating all female pediatric patients, aged 1 to 18 years, who underwent a pelvic ultrasound to evaluate for OT over a 2-year period in our pediatric emergency department. Patients suitable for inclusion were identified via Nuance mPowerTM, a search engine that provides clinical analytics based on radiology reports generated within our institution. RESULTS: We reviewed the medical records of 193 female patients aged 1 to 18 years, all of whom had a pelvic ultrasound (with or without Doppler) to evaluate for OT during the study period. In comparing ovarian size on ultrasound, patients with OT had a significantly larger magnitude of difference in ovarian volume than patients without torsion (5.57× [interquartile range, 3-12.5] vs 1.56× [interquartile range, 1.24-2.25; P < 0.001]). Ovarian torsion was associated with a 33-fold increased risk of lack of arterial flow (relative risk, 33.33) and with a 9-fold increased risk of lack of venous flow (relative risk, 9.27), when compared with those patients without OT. Patients with OT were significantly more likely to have emesis and peritoneal signs on examination, as well as previous history of OT (P = 0.01, 0.02, and 0.002, respectively) than those without OT. All patients with OT reported abdominal pain. CONCLUSIONS: We found that a large size discrepancy between ovaries is indicative of OT. Our data also suggest that presence of Doppler flow on ultrasound cannot be used to exclude OT but that lack of Doppler flow on ultrasound is a significant diagnostic marker. As previous studies have also found, clinical symptoms of OT are nonspecific and do not offer any certainty in differentiating OT from other pathologies.

Altered cerebral perfusion in response to chronic mild hypercapnia and head-down tilt Bed rest as an analog for Spaceflight.

PURPOSE: Following prolonged stays on the International Space Station (ISS), some astronauts exhibit visual acuity changes, ophthalmological findings, and mildly elevated intracranial pressures as part of a novel process called spaceflight-associated neuro-ocular syndrome (SANS). To determine the pathophysiology of SANS, NASA conducted a multi-investigator study in which 11 healthy participants underwent head-down tilt bed rest, mimicking microgravity-induced cephalad fluid shifts, combined with elevated ambient CO2 levels similar to those on the ISS (HDT+CO2). As part of that study, we examined the effects of HDT+CO2 on cerebral perfusion. METHODS: Using arterial spin labeling, we compared cerebral perfusion before, during, and after HDT+CO2 in participants who developed SANS (n = 5) with those who did not (n = 6). RESULTS: All participants demonstrated a decrease in perfusion during HDT+CO2 (mean decrease of 25.1% at HDT7 and 16.2% at HDT29); however, the timing and degree of change varied between the groups. At day 7 of HDT+CO2, the SANS group experienced a greater reduction in perfusion than the non-SANS group (p =.05, 95% CI:-0.19 to 16.11, d=.94, large effect). Conversely, by day 29 of HDT+CO2, the SANS group had significantly higher perfusion (approaching their baseline) than the non-SANS group (p = .04, 95% CI:0.33 to 13.07, d=1.01, large effect). CONCLUSION: Compared with baseline and recovery, HDT+CO2 resulted in reduced cerebral perfusion which varied based on SANS status. Further studies are needed to unravel the relative role of HDT vs hypercapnia, to determine if these perfusion changes are clinically relevant, and whether perfusion changes contribute to the development of SANS during spaceflight.

The encoding of race during face processing, an event-related potential study.

It is well known that adults spontaneously classify people into social categories and this categorization in turn guides their cognition and behavior. A wealth of research has examined how people perceive race and investigated the effect of race on social behavior. But what about race encoding? Although considerable behavioral research has investigated the encoding of race, that is, the social categorization by race, the neural underpinning of it is largely underexplored. To investigate the time course of race encoding, the current study employed a modified category verification task and a multivariate analyzing approach. We found that racial information became decodable from event-related potential topographies as early as about 200 ms after stimulus onset. At this stage, the brain can differentiate different races in a task-relevant manner. Nonetheless, it is not until 100 ms later that racial information is encoded in a socially relevant manner (own- versus other-race). Importantly, perceptual differentiation not only occurs before the encoding of the race but actually influences it: the faces that are more easily perceptually categorized are actually encoded more readily. Together, we posit that the detection and the encoding of race are decoupled although they are not completely independent. Our results provide powerful constraints toward the theory-building of race.

Effects of Spaceflight on Astronaut Brain Structure as Indicated on MRI.

BACKGROUND: There is limited information regarding the effects of spaceflight on the anatomical configuration of the brain and on cerebrospinal fluid (CSF) spaces. METHODS: We used magnetic resonance imaging (MRI) to compare images of 18 astronauts' brains before and after missions of long duration, involving stays on the International Space Station, and of 16 astronauts' brains before and after missions of short duration, involving participation in the Space Shuttle Program. Images were interpreted by readers who were unaware of the flight duration. We also generated paired preflight and postflight MRI cine clips derived from high-resolution, three-dimensional imaging of 12 astronauts after long-duration flights and from 6 astronauts after short-duration flights in order to assess the extent of narrowing of CSF spaces and the displacement of brain structures. We also compared preflight ventricular volumes with postflight ventricular volumes by means of an automated analysis of T1-weighted MRIs. The main prespecified analyses focused on the change in the volume of the central sulcus, the change in the volume of CSF spaces at the vertex, and vertical displacement of the brain. RESULTS: Narrowing of the central sulcus occurred in 17 of 18 astronauts after long-duration flights (mean flight time, 164.8 days) and in 3 of 16 astronauts after short-duration flights (mean flight time, 13.6 days) (P<0.001). Cine clips from a subgroup of astronauts showed an upward shift of the brain after all long-duration flights (12 astronauts) but not after short-duration flights (6 astronauts) and narrowing of CSF spaces at the vertex after all long-duration flights (12 astronauts) and in 1 of 6 astronauts after short-duration flights. Three astronauts in the long-duration group had optic-disk edema, and all 3 had narrowing of the central sulcus. A cine clip was available for 1 of these 3 astronauts, and the cine clip showed upward shift of the brain. CONCLUSIONS: Narrowing of the central sulcus, upward shift of the brain, and narrowing of CSF spaces at the vertex occurred frequently and predominantly in astronauts after long-duration flights. Further investigation, including repeated postflight imaging conducted after some time on Earth, is required to determine the duration and clinical significance of these changes. (Funded by the National Aeronautics and Space Administration.).

T2-Weighted-Fluid-Attenuated Inversion Recovery Hyperintensity on Magnetic Resonance Imaging Is Associated With Aggressive Symptoms in Patients With Dural Arteriovenous Fistulas.

Background and Purpose- Several angiographic factors of dural arteriovenous fistulas (dAVFs) are associated with aggressive presentation and poor natural history. We examined the association of magnetic resonance imaging T2-weighted-Fluid-Attenuated Inversion Recovery (T2/FLAIR) hyperintensity with aggressive presentation. Methods- A cohort of dAVF patients from 2 centers was retrospectively examined. T2/FLAIR hyperintensity was determined by blinded, de-identified review and compared with angiographic grade and presenting symptoms. Results- T2/FLAIR hyperintensity was only identified in dAVF patients with cortical venous drainage (CVD). Among patients with CVD, those with T2/FLAIR hyperintensity were more likely to present with aggressive symptoms (20/23, 87.0%) than those without (6/21, 28.5%), P<0.001. All cured dAVFs with symptom resolution and available post-treatment imaging had resolution of T2/FLAIR hyperintensity. Conclusions- T2/FLAIR hyperintensity strongly correlates with aggressive presentation and CVD in dAVF patients, and may identify a subset that would benefit from early treatment.

Safety and Efficacy of Combined Transarterial Embolization and Percutaneous Radiofrequency Ablation for Liver Tumors Using Cone-Beam CT and Needle Navigation Software in a Single Session.

PURPOSE: To assess the safety and efficacy of single-session transarterial embolization and radiofrequency (RF) ablation for hepatic tumors with the use of needle navigation software. MATERIALS AND METHODS: Retrospective analysis was conducted of 24 patients with liver cancer undergoing embolization followed by RF ablation between May 2014 and August 2017. Twelve patients each underwent (i) embolization and computed tomography (CT)-guided RF ablation during different sessions (group 1) and (ii) embolization followed by RF ablation with cone-beam CT and Needle Assist software in 1 session (group 2). Median age (70.5 y [range, 58-78 y] vs 70.5 y [range, 50-82 y]; P = .76) and performance status (0/1) were comparable between groups. Median tumor size was significantly larger in group 2 (2 cm [range, 1.0-7.3 cm] vs 3.2 cm [range, 1.1-9.6 cm]; P < .03). Procedure time, effective dose, and number of scans were examined. Efficacy was assessed by modified Response Evaluation Criteria In Solid Tumors after 1 month. Safety was assessed by Society of Interventional Radiology adverse event classification. RESULTS: Group 1 had a mean of 8.5 CT scans, vs a mean of 5.0 cone-beam CT scans in group 2 (P < .001). Median procedure times were 110 min in group 1 and 199.5 min in group 2 (P < .001). Median effective doses were 68.8 mSv in group 1 and 55.4 mSv in group 2 (P = .38). There was no difference in complete response between groups (66.7% vs 63.6%; P = 1). CONCLUSIONS: Transarterial embolization followed by RF ablation with cone-beam CT and needle guidance software in a single session seems to be safe and effective.

Palliative care after the Liverpool Care Pathway: a study of staff experiences.

The objective of this study was to explore nurses' perceptions of end-of-life care following the withdrawal of the Liverpool Care Pathway (LCP). Thirteen semi-structured interviews were conducted with nurses working in palliative care. Data were analysed using thematic analysis. Three themes emerged: perceptions of the LCP, prevailing issues, and patients' and families' experiences. This study suggested that the removal of the pathway has not remedied the issues attributed to it. Further, the way in which the LCP was removed indicates that the non-expert media can play a negative role in how palliative care is perceived, which inhibits the care process. In this respect it is important that 'insider' voices are also heard, in order to educate and also redress disinformation. Similarly, broader, persisting, contextual challenges facing staff need addressing in order to prevent a repeat of the issues leading to the removal of the LCP.

Transradial Versus Transfemoral Arterial Access in Liver Cancer Embolization: Randomized Trial to Assess Patient Satisfaction.

PURPOSE: To determine whether transradial access (TRA) or transfemoral access (TFA) provides better patient satisfaction during intra-arterial therapy (IAT) for liver cancer. MATERIALS AND METHODS: This randomized, prospective, intra- and interpatient controlled trial compared TRA vs TFA accesses in patients with primary or metastatic liver cancer undergoing IAT. After having one of each type of access (1 TRA and 1 TFA), all patients selected their preferred access regardless of whether a third intervention was indicated. The primary endpoint was patient access preference; secondary endpoints were access-related complications, procedure time, contrast agent volume, and radiation doses to the patient and operator. Patients were evaluated on postprocedure days 1 and 30. RESULTS: Fifty-five patients with liver cancer (31 hepatocellular carcinoma, 24 metastatic disease) were enrolled, and 124 IAT procedures were performed. A total of 36 patients underwent at least 1 intervention each with TRA and TFA. Of those, 29 patients (81%) preferred TRA and 7 (19%) preferred TFA (ratio, 4:1; P < .001). Median radiation exposure to the operator was significantly lower for TRA (5.5 mrem) vs TFA (13 mrem; P = .01). Incidences of complications, procedure time, contrast agent volume, and radiation exposure to patients were similar between groups. CONCLUSIONS: TRA was the preferred access for the majority of patients and was associated with less radiation exposure to the operator. No differences were detected in incidence of adverse events, procedure time, contrast agent volume, or patient radiation exposure.

Changes in Breast Density Reporting Patterns of Radiologists After Publication of the 5th Edition BI-RADS Guidelines: A Single Institution Experience.

OBJECTIVE: The objective of our study was to determine the impact of 5th edition BI-RADS breast density assessment guidelines on density reporting patterns in our clinical practice. MATERIALS AND METHODS: PenRad reporting system was used to collect mammographic breast density data reported by five radiologists: 16,907 density assignments using 5th edition BI-RADS guidelines were compared with 19,066 density assessments using 4th edition guidelines. Changes in the density assessment pattern were noted between the 4th and 5th edition guidelines, and agreement in density distribution was compared using the intraclass correlation coefficient. A chi-square analysis was conducted for each reader to examine the change in the proportion of dense versus nondense assignments and on each category type to examine specific changes in proportion of density assignments from the 4th to the 5th edition. All reported p values are two-sided, and statistical significance was considered at the p < 0.001 threshold. RESULTS: Using the 5th edition, there was an overall 5.0% decrease in fatty assessments (p < 0.001), 2.8% increase in scattered densities (p < 0.001), 2.6% increase in heterogeneously dense (p < 0.001), and 0.4% decrease in extremely dense assessments (p = 0.15). Comparing the dense with nondense categories, there was a 2.3% overall increase in the dense assessments (p < 0.001) using 5th edition guidelines, mainly in the heterogeneously dense category. Two radiologists showed increased dense assessments (p < 0.001) using the 5th edition, and three radiologists showed no change (p = 0.39, 0.67, and 0.76). CONCLUSION: There was an overall increase in the dense assessments using the 5th edition, but individual radiologists in our clinical practice showed a variable adaptation to new guidelines.

Effectiveness of a Mobile Mammography Program.

OBJECTIVE: Mobile mammography units have increasingly been used to address patient health care disparities; however, there are limited data comparing mobile units to stationary sites. This study aims to evaluate the characteristics of women who underwent mammography screening in a mobile unit versus those who underwent mammography screening at a cancer center. MATERIALS AND METHODS: In this retrospective study, we analyzed all screening mammography examinations performed in a mobile unit in 2014 (n = 1433 examinations). For comparison, we randomized and reviewed an equivalent number of screening mammography examinations performed at our cancer center in 2014 (n = 1434 examinations). BI-RADS assessment, adherence to follow-up, biopsies performed, cancer detection rate, and sociodemographic variables were recorded. An independent-samples t test was conducted to identify potential differences in age between cancer center patients and mobile unit patients. Chi-square analyses were used to test for associations between location and factors such as health insurance, race, marital status, geographic area, adherence to screening guidelines, recall rate, adherence to follow-up, and cancer detection rates. RESULTS: Patients visiting our cancer center (mean = 57.74 years; SD = 10.55) were significantly older than those visiting the mobile unit (mean = 52.58 years; SD = 8.19; p < 0.001). There was a significant association between location and health insurance status (χ2 = 610.92; p < 0.001) with more uninsured patients undergoing screening in the mobile van (cancer center = 3.70%, mobile unit = 38.73%). There was a significant association between screening location and patient race (χ2 = 118.75, p < 0.001), with more white patients being screened at the cancer center (cancer center = 47.28%, mobile unit = 33.30%), more black patients being screened in the mobile van (cancer center = 49.30%, mobile unit = 54.15%), and more Hispanic patients being screened in the mobile van (cancer center = 1.05%, mobile unit = 6.77%). There was a significant association between location and patient marital status (χ2 = 135.61, p < 0.001), with more married patients screened at the cancer center (cancer center = 49.16%, mobile unit = 38.31%), more single patients screened in the mobile van (cancer center = 25.17%, mobile unit = 34.47%), and more widowed patients being screened at the cancer center (cancer center = 8.09%, mobile unit = 4.47%). There was a significant association between location and geographic area (χ2 = 33.33, p < 0.001), with both locations reaching more urban than rural patients (cancer center = 79.99%, mobile unit = 70.62%). There was a significant association between location and adherence to screening guidelines (χ2 = 179.60, p < 0.001), with patients screened at the cancer center being more compliant (cancer center = 56.90%, mobile unit = 34.47%). Finally, there was a significant association between location and recall rate (χ2 = 4.06, p < 0.001). The cancer center had a lower recall rate (13.32%) than the mobile van (15.98%). Of those patients with BI-RADS 0, there was a significant association between location and adherence to follow-up (χ2 = 22.75, p < 0.001) with patients using the mobile unit less likely to return for additional imaging (cancer center = 2.65%, mobile unit = 17.03%). CONCLUSION: Significant differences were found among patients visiting the cancer center versus the mobile mammography van. The cancer center's population is older and more adherent to guidelines, whereas the mobile mammography population exhibited greater racial and marital diversity, higher recall rate, and lack of adherence to follow-up recommendations. By identifying these characteristics, we can develop programs and materials that meet these populations' needs and behaviors, ultimately increasing mammography screening and follow-up rates among underserved populations.

Reformatted images improve the detection rate of acute traumatic subdural hematomas on brain CT compared with axial images alone.

Subdural hematomas (SDHs) comprise a significant percentage of missed intracranial hemorrhage on axial brain CT. SDH detection rates could be improved with the addition of reformatted images. Though performed at some centers, the potential additional diagnostic sensitivity of reformatted images has not yet been investigated. The purpose of our study is to determine if the addition of coronal and sagittal reformatted images to an axial brain CT increases the sensitivity and specificity for detection of acute traumatic SDH. We retrospectively reviewed consecutive brain CTs acquired for acute trauma that contained new SDHs. An equivalent number of normal brain CTs served as control. Paired sets of images were created for each case: (1) axial images only ("axial only") and (2) axial, coronal, sagittal images ("reformat added"). Three readers interpreted both the axial only and companion reformat added for each case, separated by 1 month. Reading times and SDH detection rates were compared. One hundred SDH and 100 negative examinations were collected. Sensitivity and specificity for the axial-only scans were 75.7 and 94.3 %, respectively, compared with 88.3 and 98.3 % for reformat added. There was a 24.3 % false negative (missed SDH) rate with axial-only scans versus 11.7 % with reformat added (p = <0.001). Median reader interpretation times were longer with the addition of reformatted images (125 versus 89 s), but this difference was not significant (p = 0.23). The addition of coronal and sagittal images in trauma brain CT resulted in improved sensitivity and specificity as well as a reduction in SDH false negatives by greater than 50 %. Reformatted images substantially reduce the number of missed SDHs compared with axial images alone.

Distress experienced during pediatric VCUGs - a granular, prospective assessment using the brief behavioral distress scale.

BACKGROUND: In spite of decades of experience with the procedure, controversy persists as to the overall distress experienced by children and the routine need for sedation in children undergoing voiding cystourethrograms (VCUG). Many studies have attempted to address these issues, often divided into one camp that champions routine sedation while another group believes that pretest preparation is often all that is needed. At the root of these issues are some of the limitations of previous studies as most incorporate inherently subjective parental questionnaires to determine distress levels rather than using an objective, unbiased observer. OBJECTIVE: The objective of this study is to use a validated and reliable tool (the brief behavioral distress scale) to objectively evaluate the distress experienced during VCUGs. MATERIALS AND METHODS: A prospective study of 26 children (ages 3-7 years old) was performed by the pediatric radiology department at a large urban academic medical center. Patients were evaluated for distress during 12 separate VCUG steps beginning with the patient entering the room and ending with the clothing being replaced at study completion. RESULTS: Using a general linear model (repeated measures analysis of variance (ANOVA)), significant distress was identified during two phases of the examination, catheter insertion (P-values ranging <0.001-0.19) and the full bladder phase (P-values ranging 0.005-0.043). The mean distress score for catheter insertion (mean: 1.38, standard deviation [SD]: 1.098) was nearly three times higher than the next most distressful step, i.e. full bladder (mean: 0.65, SD: 0.745). Additionally, entering the room was perceived as significantly more distressing than the catheter out (P = 0.016) and clothing replacement phase (P = 0.006). CONCLUSION: We find that despite there being significantly increased distress during the catheter insertion and full bladder phases, the distress levels during VCUGs are markedly less than in previous reports. Even the most distressful stage, catheterization, was less stressful than previously reported with levels closer to that of minor distress evinced by comfort-seeking behavior from a parent rather than more significant distress resulting in screaming. Our findings corroborate and expand on the conclusion of the effectiveness of pretest preparation and child life specialist involvement.

Radiation exposure contribution of the scout abdomen radiograph in common pediatric fluoroscopic procedures.

BACKGROUND: Contrast enema, voiding cystourethrography and upper gastrointestinal studies are the most common fluoroscopic procedures in children. Scout abdomen radiographs have been routinely obtained prior to fluoroscopy and add to the radiation exposure from these procedures. Elimination of unnecessary routine scout radiographs in select studies might significantly reduce radiation exposure to children and improve the overall benefit-to-risk ratio of these fluoroscopic procedures. OBJECTIVE: To determine the radiation exposure contribution of the preliminary/scout abdomen radiographs with respect to the radiation exposure of the total procedure. MATERIALS AND METHODS: We retrospectively collected demographic information and radiation exposure values of dose area product (in Gy-cm(2)) and entrance air kerma (in mGy) - initially for the scout abdomen radiographs done prior to fluoroscopy and subsequently the total procedural radiation values (the combined values of the scout radiograph and fluoroscopic radiation exposure) - in children who underwent contrast enemas, voiding cystourethrograms and upper gastrointestinal studies in a 4-month period. The radiation parameters, including fluoroscopy time, dose area product and entrance air kerma, were available in the log book maintained in the fluoroscopy suite. Fluoroscopy procedures were performed on a single fluoroscopy machine using four frames per second pulse rate and other radiation-minimizing techniques. Usage of the grid to obtain scout radiographs was also recorded. The proportion of radiation exposure from the scout radiograph relative to that of the total procedure was calculated by dividing the individual parameters of the scout to the total procedural values and multiplied by 100 to express these values as a percentage. We calculated mean, median and range and performed statistical analysis of the data. RESULTS: A total of 151 procedures performed on 71 males and 80 females qualified for the study. The age range of the patients was 2 days to 18 years, with a mean of nearly 3.5 years (40 months) and median of 15 months. There were 63 upper gastrointestinal studies, 65 voiding cystourethrography studies and 23 contrast enema studies. The fluoroscopy time for all procedures combined ranged from 0.1 min (6 s) to 2 min, with mean and median values of 0.4 min and 0.3 min, respectively. The fractional radiation exposure contribution for the dose area product of scout abdomen radiograph to the total procedure ranged from 4% to 98%, with mean and median values of 51% and 49%, respectively. The fractional contribution of the scout radiograph to the total procedure for the entrance air kerma values ranged from 6% to 97%, with mean and median values of 29% and 26%, respectively. There was a significant negative correlation (P<0.001) between fluoroscopy radiation time and the proportion of radiation parameters of scout radiograph to total procedural values. CONCLUSION: Scout radiographs can contribute a significant proportion (median values of approximately 50% for the dose area product and 26% for the entrance air kerma) of radiation exposure in common fluoroscopy procedures in children.

Instituting a radiology residency scholarly activity program.

BACKGROUND: The purpose of this manuscript is to present a newly instituted program for resident scholarly activity that includes a curriculum designed to enhance resident training with regard to research while meeting requirements established by the Accreditation Council for Graduate Medical Education (ACGME), the governing body responsible for regulation of post-graduate medical education and training in the United States. METHODS: A scholarly activity program was designed with the following goals: (i) enhance the academic training environment for our residents; (ii) foster interests in research and academic career paths; (iii) provide basic education on research methodology and presentation skills. To guide program design, an electronic survey was created and distributed to the residents and faculty in the Department of Radiology and Radiological Sciences at the Medical University of South Carolina (MUSC), a 750-bed public teaching hospital in the state of South Carolina in the United States. RESULTS: Survey respondents were in strong support of a required resident scholarly activity project (70% in favor), felt non-traditional projects were valuable (84.1% of respondents), and were proponents of required scholarly activity summary presentations (58%). This program requires that residents engage in a scholarly activity project under the guidance of a mentor. Resident success is maximized through in-house education initiatives focusing on presentation and research skills, protected time to work on the project, and oversight by a radiology research committee. All residents present a summary of their work near the end of their residency training. DISCUSSION: Changes to the radiology resident certification process create an opportunity for incorporating new policies aimed at enhancing resident education. The scholarly activity program outlined in this manuscript is one such initiative designed to meet ACGME requirements, provide an introduction to research, and establish a scholarly activity project requirement.

Histological correlation of diffusional kurtosis and white matter modeling metrics in cuprizone-induced corpus callosum demyelination.

The cuprizone mouse model is well established for studying the processes of both demyelination and remyelination in the corpus callosum, and it has been utilized together with diffusion tensor imaging (DTI) to investigate myelin and axonal pathology. Although some underlying morphological mechanisms contributing to the changes in diffusion tensor (DT) metrics have been identified, the understanding of specific associations between histology and diffusion measures remains limited. Diffusional kurtosis imaging (DKI) is an extension of DTI that provides metrics of diffusional non-Gaussianity, for which an associated white matter modeling (WMM) method has been developed. The main goal of the present study was to quantitatively assess the relationships between diffusion measures and histological measures in the mouse model of cuprizone-induced corpus callosum demyelination. The diffusional kurtosis (DK) and WMM metrics were found to provide additional information that enhances the sensitivity to detect the morphological heterogeneity in the chronic phase of the disease process in the rostral segment of the corpus callosum. Specifically, in the rostral segment, axonal water fraction (d = 2.6; p < 0.0001), radial kurtosis (d = 2.0; p = 0.001) and mean kurtosis (d = 1.5; p = 0.005) showed the most sensitivity between groups with respect to yielding statistically significant p values and high Cohen's d values. These results demonstrate the ability of DK and WMM metrics to detect white mater changes and inflammatory processes associated with cuprizone-induced demyelination. They also validate, in part, the application of these new WMM metrics for studying neurological diseases, as well as helping to elucidate their biophysical meaning.

Qualitative and quantitative spermatic cord abnormalities at CT predict symptomatic scrotal pathology.

PURPOSE: To evaluate quantitative and qualitative spermatic cord CT abnormalities and presence of unilateral or bilateral symptomatic scrotal pathology (SSP) at ultrasound. METHODS: This retrospective study included 122 male patients (mean age 47.8 years) undergoing scrotal ultrasound within 24 h of contrast-enhanced CT (n = 85), non-contrast CT (NECT, n = 32) or CT-Urogram (n = 5). CECT quantitative analysis assessed differential cord enhancement using maximum Hounsfield unit measurements. Three fellowship trained body radiologists independently assessed qualitative cord abnormalities for both CECT and NECT. Qualitative and quantitative findings were compared with the presence of SSP. Reader performance, interobserver agreement and reader confidence were assessed for NECT and CECT. Quantitative cutoff points were identified which maximized accuracy, specificity, negative predictive value, and other measures. RESULTS: SSP was present in 36/122 patients (29.5%). Positive cases were unilateral in 30 (83.3%) and bilateral in 6 (16.6%). At quantitative assessment, 25% differential cord enhancement had the highest diagnostic accuracy (88.9%), with 90.5% positive predictive value, 88.4% negative predictive value, 96.8% specificity, and 70.4% sensitivity. At qualitative evaluation, CECT reader performance was excellent (aggregate AUC = 0.86; P < .001); NECT was poorly discriminatory, although remained significant (aggregate AUC = 0.67; P = .002). Readers had significantly higher confidence levels with CECT (P < .001). Qualitative inter-observer agreement was high for both CECT and NECT (ICC = 0.981 and 0.963, respectively). CONCLUSION: Simple quantitative assessment of differential cord enhancement is highly accurate and specific for SSP at CECT. Qualitative abnormalities at CECT and NECT are also both predictors of SSP, however, CECT significantly out-performs non-contrast exams.

Physician self-referral: frequency of negative findings at MR imaging of the knee as a marker of appropriate utilization.

PURPOSE: To determine whether ownership of magnetic resonance (MR) imaging equipment by ordering physicians affects the likelihood of positive findings at MR imaging of the knee and to evaluate rates of knee abnormalities seen at MR imaging as a metric for comparison of utilization. MATERIALS AND METHODS: The institutional review board approved this retrospective HIPAA-compliant study and waived the need for informed consent. A retrospective review was performed of consecutive diagnostic MR images of the knee interpreted by one radiology practice between January and April 2009 for patients who had been referred by two separate physician groups serving the same geographic community: one with financial interest (FI) in the MR imaging equipment used and one with no FI (NFI) in the MR imaging equipment used. The percentage of examinations with negative results was tabulated for both groups, and the relative frequency of each abnormality subtype was calculated among the studies with positive findings in each group. To examine frequency differences among groups, χ(2) tests were used, and to examine mean differences among groups, t tests were used. RESULTS: Of 700 examinations, 205 had negative results (117 of 350 in the FI group and 88 of 350 in the NFI group, P = .016). Among the examinations with positive results, the mean total number of positive abnormality subtypes per image did not significantly differ between groups: 1.52 for the FI group and 1.53 for the NFI group (P = .96). CONCLUSION: MR images of the knee among patients referred by the FI group were significantly more likely to be negative than those among patients referred by the NFI group. Frequency of abnormality subtype and distribution among examinations with positive results suggests a highly similar distribution and severity of abnormalities between the two patient groups.

Altered thyroid function in severely injured patients.

BACKGROUND: Hemorrhagic shock profoundly affects the neuroendocrine profile of trauma patients, and we hypothesized that massive resuscitation would negatively impact thyroid function. METHODS: A prospective, observational study investigating thyroid function in hypotensive trauma patients (systolic blood pressure <90 mm Hg × 2) who survived >48 h was conducted at a Level I center over a 6-mo period. Blood samples for thyroid function were collected at time of presentation to the trauma bay and serially for 48 h. Collected data included demographics, injury data, vital signs, transfusion needs, crystalloid use, and vasopressor requirements. Patients receiving >5 units packed red blood cells (PRBC) within 12 h were compared with those receiving ≤5 units. RESULTS: Patients who required >5 units of PRBC/12 h had significantly lower total and free T4 levels on initial presentation, and levels remained significantly depressed over the next 48 h when compared with patients who required a less aggressive resuscitative effort. T3 values were markedly suppressed during the initial 48 h post trauma in all patients, but were significantly lower in patients requiring >5 units PRBC. TSH levels remained within the normal range for all time points. Lower trauma admission T4 levels were associated with the need for greater crystalloid resuscitation within the first 24 h. CONCLUSION: Measurements of thyroid function are significantly altered in severely injured patients on initial presentation, and low T4 levels predict the need for large resuscitation. Further research investigating the profile and impact of thyroid function in trauma patients during resuscitation and recovery is warranted.