A 1-Tesla MRI system for dedicated brain imaging in the neonatal intensive care unit.

Objective: To assess the feasibility of a point-of-care 1-Tesla MRI for identification of intracranial pathologies within neonatal intensive care units (NICUs). Methods: Clinical findings and point-of-care 1-Tesla MRI imaging findings of NICU patients (1/2021 to 6/2022) were evaluated and compared with other imaging modalities when available. Results: A total of 60 infants had point-of-care 1-Tesla MRI; one scan was incompletely terminated due to motion. The average gestational age at scan time was 38.5 ± 2.3 weeks. Transcranial ultrasound (n = 46), 3-Tesla MRI (n = 3), or both (n = 4) were available for comparison in 53 (88%) infants. The most common indications for point-of-care 1-Tesla MRI were term corrected age scan for extremely preterm neonates (born at greater than 28 weeks gestation age, 42%), intraventricular hemorrhage (IVH) follow-up (33%), and suspected hypoxic injury (18%). The point-of-care 1-Tesla scan could identify ischemic lesions in two infants with suspected hypoxic injury, confirmed by follow-up 3-Tesla MRI. Using 3-Tesla MRI, two lesions were identified that were not visualized on point-of-care 1-Tesla scan: (1) punctate parenchymal injury versus microhemorrhage; and (2) small layering IVH in an incomplete point-of-care 1-Tesla MRI with only DWI/ADC series, but detectable on the follow-up 3-Tesla ADC series. However, point-of-care 1-Tesla MRI could identify parenchymal microhemorrhages, which were not visualized on ultrasound. Conclusion: Although limited by field strength, pulse sequences, and patient weight (4.5 kg)/head circumference (38 cm) restrictions, the Embrace® point-of-care 1-Tesla MRI can identify clinically relevant intracranial pathologies in infants within a NICU setting.

Using an Annual Diversity, Equity and Inclusion Dashboard to Accelerate Change in Academic Radiology Departments.

Despite widespread interest in creating a more equitable and inclusive culture, a lack of workforce diversity persists in Radiology, in part due to a lack of universal and longitudinal metrics across institutions. In an attempt to establish benchmarks, a subset of the Society of Chairs of Academic Radiology Departments (SCARD) Diversity, Equity and Inclusion (DEI) Committee volunteered to design a DEI dashboard as a potential tool for academic radiology programs to use to document and track their progress. This freely-available, modular dashboard includes suggested (plus optional department-defined) DEI activities/parameters and suggested assessment criteria across three domains: faculty, residents & fellows, and medical students; it can be completed, in whole or in part, by departmental leaders annually. The suggested metrics and their associated rubrics were derived from the collective experiences of the five working group members, all of whom are chairs of academic radiology departments. The resulting dashboard was unanimously approved by the remaining 14 DEI committee members and endorsed by the SCARD board of directors.

Directional control of neurite outgrowth: emerging technologies for Parkinson's disease using magnetic nanoparticles and magnetic field gradients.

A challenge in current stem cell therapies for Parkinson's disease (PD) is controlling neuronal outgrowth from the substantia nigra towards the targeted area where connectivity is required in the striatum. Here we present progress towards controlling directional neurite extensions through the application of iron-oxide magnetic nanoparticles (MNPs) labelled neuronal cells combined with a magnetic array generating large spatially variant field gradients (greater than 20 T m-1). We investigated the viability of this approach in both two-dimensional and organotypic brain slice models and validated the observed changes in neurite directionality using mathematical models. Results showed that MNP-labelled cells exhibited a shift in directional neurite outgrowth when cultured in a magnetic field gradient, which broadly agreed with mathematical modelling of the magnetic force gradients and predicted MNP force direction. We translated our approach to an ex vivo rat brain slice where we observed directional neurite outgrowth of transplanted MNP-labelled cells from the substantia nigra towards the striatum. The improved directionality highlights the viability of this approach as a remote-control methodology for the control and manipulation of cellular growth for regenerative medicine applications. This study presents a new tool to overcome challenges faced in the development of new therapies for PD.

Routine exercise-based cardiac rehabilitation does not increase aerobic fitness: A CARE CR study.

BACKGROUND: Recent evidence suggests that routine exercise-based cardiac rehabilitation (CR) may not lead to a substantial increase in estimated peak oxygen uptake (V̇O2peak). This could reduce the potential benefits of CR and explain why CR no longer improves patient survival in recent studies. We aimed to determine whether routine exercise-based CR increases V̇O2peak using gold-standard maximal cardiopulmonary exercise testing (CPET), and to quantify the exercise training stimulus which might be insufficient in patients undertaking CR. METHODS: We studied the effects of a routine, twice weekly, exercise-based CR programme for eight weeks (intervention group) compared with abstention from supervised exercise training (control group) in patients with coronary heart disease. The primary outcome was V̇O2peak measured using CPET. We also measured changes in body composition using dual X-ray absorptiometry, carotid intima-media thickness, hs-CRP and N-terminal pro B-type natriuretic peptide at baseline, 10 weeks and 12 months. We also calculated the Calibre 5-year all-cause mortality risk score. RESULTS: Seventy patients (age 63.1 SD10.0 years; BMI 29.2 SD4.0 kg·m-2; 86% male) were recruited (n = 48 intervention; n = 22 controls). The mean aerobic exercise training duration was 23 min per training session, and the mean exercise training intensity was 45.9% of heart rate reserve. V̇O2peak was 23·3 ml·kg-1·min-1 at baseline, and there were no changes in V̇O2peak between groups at any time point. The intervention had no effect on any of the secondary endpoints. CONCLUSION: Routine CR does not lead to an increase in V̇O2peak and is unlikely to improve long-term physiological outcomes.

International round-robin experiment for angle-resolved light scattering measurement.

An international round-robin experiment has been conducted to test procedures and methods for the measurement of angle-resolved light scattering. ASTM E2387-05 has been used as the main guide, while the experience gained should also contribute to the new ISO standard of angle-resolved scattering currently under development (ISO/WD 19986:2016). Seven laboratories from Europe and the United States measured the angle-resolved scattering from Al/SiO2-coated substrates, transparent substrates, volume diffusors, quasi-volume diffusors, white calibration standards, and grating samples at laser wavelengths in the UV, VIS, and NIR spectra. Results were sent to Fraunhofer IOF, which coordinated the experiments and analyzed the data, while ESA-ESTEC, as the project donor, defined conditions and parameters. Depending mainly on the sample type, overall good to reasonable agreements were observed, with largest deviations at scattering angles very close to the specular beam. Volume diffusor characterization unexpectedly turned out to be challenging. Not all participants provided measurement uncertainty ranges according to the Guide to the Expression of Uncertainty in Measurement; often, a single general scatterometer-related measurement uncertainty value was stated. Although relative instrument measurement uncertainties close to 1% are sometimes claimed, the comparison results did not support these claims for specular scattering samples as mirrors, substrates, or gratings.

The Late-Career Radiologist: Options and Opportunities.

More than 25% of the present radiology workforce, or nearly 8300 radiologists, are actively practicing late-career radiologists. While these individuals could decide to retire from active practice, their continued presence in the workforce helps to maintain adequate and appropriate patient imaging services. To ensure their continued participation, issues important to all late-career radiologists need to be appreciated, discussed, and addressed. These issues include call-duty requirements, compensation, physical and cognitive health, and organized phase-out programs. The gamut of these issues is addressed in this review article. ©RSNA, 2018.

Millimeter-Wave Beam Scattering by Field-Aligned Blobs in Simple Magnetized Toroidal Plasmas.

The first direct experimental measurements of the scattering of a millimeter-wave beam by plasma blobs in a simple magnetized torus are reported. The wavelength of the beam is comparable to the characteristic size of the blob. In situ Langmuir probe measurements show that fluctuations of the electron density induce correlated fluctuations of the transmitted power. A first-principles full-wave model, using conditionally sampled 2D electron density profiles, predicts fluctuations of the millimeter-wave power that are in agreement with experiments.

Optically isolated millimeter-wave detector for the Toroidal Plasma Experiment.

We have designed and built an optically isolated millimeter-wave detection system to prevent interference from a nearby, powerful, 2.45 GHz microwave source in millimeter-wave propagation experiments in the TORoroidal Plasma EXperiment (TORPEX). A series of tests demonstrates excellent system noise immunity and the ability to observe effects that cannot be resolved in a setup using a bare Schottky diode detector.

Proctoring of New Emergency Radiologists to Promote Clinical Excellence and Ensure Quality of Care.

PURPOSE: The authors' institution provides 24/7 attending radiologist final interpretations for all emergency, urgent, and inpatient studies. As a supplement to the existing emergency radiology faculty, the institution relies on two groups of radiologists to provide final imaging interpretations after hours: radiology fellows (RFs) and newly hired subspecialty radiologists (NRs). For both groups, subspecialty services provide overreads the following day to improve the skills of the staff members and ensure clinical excellence. The purpose of this study was to compare the clinical significance and rate of discrepancies between RFs and NRs. METHODS: A retrospective review of all overreads from July 1, 2012, to June 30, 2015, was performed. Discrepancy rates for RFs and NRs were calculated. Error significance for cases requiring addenda was categorized as follows: acute, likely malignant, indeterminate, unlikely to be of clinical significance, insignificant typographic error, or significant typographic error. RESULTS: In total, 10,796 studies were rechecked, of which 1.9% (n = 205) required addenda, 3.6% (n = 384) were deemed addendum-optional, and 94.5% (n = 10,207) required no comments. There was no significant difference in cases requiring addenda (RFs, 1.7% [119 of 6,847]; NRs, 2.2% [86 of 3,949]; P = .11). Of the 205 cases requiring addenda, 21.0% (n = 43) were deemed to be acute, 4.9% (n = 10) likely malignant, 28.3% (n = 58) indeterminate, 32.7% (n = 67) unlikely to be of clinical significance, and 13.1% (n = 27) secondary to typographic errors (66.7% [n = 18] deemed to be significant). CONCLUSIONS: After-hours coverage with RFs and NRs allows high-quality final, actionable interpretations with low discrepancy rates and no significant difference between both groups for addendum-needed cases. The program strikes a balance between the need for timely interpretations and the need to continually monitor and improve the quality of interpretations through subspecialist feedback.

3D printing from diagnostic images: a radiologist's primer with an emphasis on musculoskeletal imaging-putting the 3D printing of pathology into the hands of every physician.

Three-dimensional (3D) printing has recently erupted into the medical arena due to decreased costs and increased availability of printers and software tools. Due to lack of detailed information in the medical literature on the methods for 3D printing, we have reviewed the medical and engineering literature on the various methods for 3D printing and compiled them into a practical "how to" format, thereby enabling the novice to start 3D printing with very limited funds. We describe (1) background knowledge, (2) imaging parameters, (3) software, (4) hardware, (5) post-processing, and (6) financial aspects required to cost-effectively reproduce a patient's disease ex vivo so that the patient, engineer and surgeon may hold the anatomy and associated pathology in their hands.

Sonographic distinction between acute suppurative appendicitis and viral appendiceal lymphoid hyperplasia ("pink appendix") with pathological correlation.

The viral etiology of mesenteric lymphadenitis may also affect the lymphoid tissue of the appendix in children giving rise to symptomatic appendiceal lymphoid hyperplasia, the so-called "pink appendix." The present study used ultrasound (US) to determine if certain sonographic features correlated with appendiceal pathological findings. Our results indicate that a fluid-filled appendix always correlates with a suppurative or mixed pathological appearance that likely merits surgery. A lymphoid predominant pathological appearance occurred only in cases where appendiceal wall thickening alone was seen on US. This pilot project therefore shows that US has the potential to stratify acute appendix patients into different treatment regimens, given that lymphoid hyperplasia could be treated conservatively. Further studies correlating other clinicoradiological parameters with this sonographic appearance are warranted.

Incidence and acute complications of asymptomatic central venous catheter-related deep venous thrombosis in critically ill children.

OBJECTIVE: To determined the current incidence and acute complications of asymptomatic central venous catheter (CVC)-related deep venous thrombosis (DVT) in critically ill children. STUDY DESIGN: We performed a prospective cohort study in 3 pediatric intensive care units. A total of 101 children with newly inserted untunneled CVC were included. CVC-related DVT was diagnosed using compression ultrasonography with color Doppler. RESULTS: Asymptomatic CVC-related DVT was diagnosed in 16 (15.8%) children, which equated to 24.7 cases per 1000 CVC-days. Age was independently associated with DVT. Compared with children aged <1 year, children aged >13 years had significantly higher odds of DVT (aOR, 14.1, 95% CI, 1.9-105.8; P = .01). Other patient demographics, interventions (including anticoagulant use), and CVC characteristics did not differ between children with and without DVT. Mortality-adjusted duration of mechanical ventilation, a surrogate for pulmonary embolism, was statistically similar in the 2 groups (22 ± 9 days in children with DVT vs 23 ± 7 days in children without DVT; P = .34). Mortality-adjusted intensive care unit and hospital lengths of stay also were similar in the 2 groups. CONCLUSION: Asymptomatic CVC-related DVT is common in critically ill children. However, the acute complications do not seem to differ between children with and without DVT. Larger studies are needed to confirm these results. Future studies should also investigate the chronic complications of asymptomatic CVC-related DVT.

Underutilized ultrasound applications in the neonatal intensive care unit.

Bedside duplex/color Doppler sonography is used for a wide gamut of abnormalities encountered in the neonatal intensive care unit. This article emphasizes the use of bedside sonography for evaluation of infants with necrotizing enterocolitis, infants requiring line placement, and those in whom a diaphragmatic abnormality is suspected. Although the assessment of those infants requires excellent operator skills, learning to do so is a definite benefit to these babies who would otherwise be exposed to ionizing radiation.

Medical imaging radiation safety for the female patient: rationale and implementation.

For the modern practitioner of women's imaging, achieving a balance between the positive diagnostic benefits available from current medical imaging on the one hand, and the potentially deleterious effects of ionizing radiation exposure on the other, has become a central issue. Increased public and professional awareness of the side effects of radiation now require a comprehensive understanding of the facts involved, the various risks to which patients are exposed, and the measures that can be implemented to minimize these risks. The major challenges posed by pregnancy, radiosensitive breast tissue, lactation, and an inability to easily exclude ovaries from the imaging field make female patients particularly vulnerable to medical imaging radiation exposure. The nature of this vulnerability changes frequently and depends on the imaging being performed, the age of the patient, and the clinical situation. For this reason, attention to gynecologic imaging radiation exposure across the whole life span is vitally important.

Note: three-dimensional stereolithography for millimeter wave and terahertz applications.

Metal-coated polymers shaped by 3D stereolithography are introduced as a new manufacturing method for passive components for millimeter to terahertz electromagnetic waves. This concept offers increased design capabilities and flexibilities while shortening the manufacturing process of complex shapes, e.g., corrugated horns, mirrors, etc. Tests at 92.5, 140, and 170 GHz are reported.

Diagnosis of intussusception by physician novice sonographers in the emergency department.

STUDY OBJECTIVE: We investigate the performance characteristics of bedside emergency department (ED) ultrasonography by nonradiologist physician sonographers in the diagnosis of ileocolic intussusception in children. METHODS: This was a prospective, observational study conducted in a pediatric ED of an urban tertiary care children's hospital. Pediatric emergency physicians with no experience in bowel ultrasonography underwent a focused 1-hour training session conducted by a pediatric radiologist. The session included a didactic component on sonographic appearances of ileocolic intussusception, review of images with positive and negative results for intussusceptions, and a hands-on component with a live child model. On completion of the training, a prospective convenience sample study was performed. Children were enrolled if they were to undergo diagnostic radiology ultrasonography for suspected intussusception. Bedside ultrasonography by trained pediatric emergency physicians was performed and interpreted as either positive or negative for ileocolic intussusception. Ultrasonographic studies were then performed by diagnostic radiologists, and their results were used as the reference standard. Test characteristics (sensitivity, specificity, positive and negative predictive values) and likelihood ratios were calculated. RESULTS: Six pediatric emergency physicians completed the training and performed the bedside studies. Eighty-two patients were enrolled. The median age was 25 months (range 3 to 127 months). Thirteen patients (16%) received a diagnosis of ileocolic intussusception by diagnostic radiology. Bedside ultrasonography had a sensitivity of 85% (95% confidence interval [CI] 54% to 97%), specificity of 97% (95% CI 89% to 99%), positive predictive value of 85% (95% CI 54% to 97%), and negative predictive value of 97% (95% CI 89% to 99%). A positive bedside ultrasonographic result had a likelihood ratio of 29 (95% CI 7.3 to 117), and a negative bedside ultrasonographic result had a likelihood ratio of 0.16 (95% CI 0.04 to 0.57). CONCLUSION: With limited and focused training, pediatric emergency physicians can accurately diagnose ileocolic intussusception in children by using bedside ultrasonography.

Sawtooth pacing by real-time auxiliary power control in a tokamak plasma.

In the standard scenario of tokamak plasma operation, sawtooth crashes are the main perturbations that can trigger performance-degrading, and potentially disruption-generating, neoclassical tearing modes. This Letter demonstrates sawtooth pacing by real-time control of the auxiliary power. It is shown that the sawtooth crash takes place in a reproducible manner shortly after the removal of that power, and this can be used to precisely prescribe, i.e., pace, the individual sawteeth. In combination with preemptive stabilization of the neoclassical tearing modes, sawtooth pacing provides a new sawtooth control paradigm for improved performance in burning plasmas.