Adaptation of family-based treatment within an inpatient medical stabilization program for children with eating disorders.

OBJECTIVE: Eating disorders are serious psychiatric conditions predominantly affecting children, adolescents, and young adults. While family-based treatment (FBT) is the gold standard outpatient treatment approach for adolescents with restrictive eating disorders, there is not a universally recognized best practice within higher levels of care. There is a particular dearth of literature detailing recommended psychological and behavioral interventions in the inpatient medical setting. METHOD: The present article provides an account of how FBT principles have been incorporated in Children's Hospital of Orange County at Mission's inpatient medical stabilization program for children and adolescents with restrictive eating disorders. Practical examples illustrate how key FBT tenets are successfully translated into the inpatient multidisciplinary setting. RESULTS: The use of FBT can encourage a unified approach among medical and psychosocial providers and serves to destigmatize patients with eating disorders and associated behaviors. The successes and challenges of FBT implementation are discussed. DISCUSSION: Though anecdotal evidence and preliminary findings support positive outcomes from the implementation of FBT within a pediatric medical stabilization program for patients, families, and staff, research is needed to understand best practices within higher levels of care. Additional research efforts will also help elucidate whether adapted FBT can become a standard of care for patients with restrictive eating disorders in inpatient settings. PUBLIC SIGNIFICANCE: This article describes how a children's hospital has adopted family-based treatment (FBT) for youth who are hospitalized due to an eating disorder. FBT is the most efficacious treatment for youth with eating disorders. This article describes specific examples of how FBT can be implemented within a medical setting. This article will support a greater understanding of FBT principles and guide providers to translate FBT into higher level of care settings.

Correspondence between development of cytotoxic edema and cerebrospinal fluid volume and flow in the third ventricle after ischemic stroke.

OBJECTIVES: The importance of monitoring cerebrospinal fluid for the development of edema in ischemic stroke has been emphasized; however, studies on the relationship between intraventricular cerebrospinal fluid behavior and edema through longitudinal observations and analysis are rare. This study aimed to investigate the correlation between the development of cytotoxic edema and cerebrospinal fluid volume and flow in the third ventricle after ischemic stroke. MATERIALS AND METHODS: The ventricle and edema regions were obtained using apparent diffusion coefficients and T2 and subdivided into lateral/ventral 3rd ventricles and cytotoxic/vasogenic (or cyst) edema, respectively. In rat models of ischemic stroke, the volume and flow (via the pseudo-diffusion coefficient [D*]) of the ventricles and edema volumes were longitudinally monitored for up to 45 days after surgery. RESULTS: The volume of cytotoxic edema increased in the hyperacute and acute phases, whereas the volume (r = -0.49) and median D* values (r = -0.48 in the anterior-posterior direction) of the ventral 3rd ventricle both decreased, showing negative correlations with the volume of cytotoxic edema. In contrast, the volume of vasogenic edema/cyst was positively correlated with the volume (r = 0.73) and median D* values (r = 0.78 in the anterior-posterior direction) of the lateral ventricle in the subacute and chronic phases. CONCLUSIONS: This study showed that the evolution of cerebrospinal fluid volume and flow in the ventricles was associated with edema progression at different time points in the ischemic stroke brain. This provides an efficient framework for monitoring and quantifying the interplay between cerebrospinal fluid and edema.

Improved laminar specificity and sensitivity by combining SE and GE BOLD signals.

The most widely used gradient-echo (GE) blood oxygenation level-dependent (BOLD) contrast has high sensitivity, but low specificity due to draining vein contributions, while spin-echo (SE) BOLD approach at ultra-high magnetic fields is highly specific to neural active sites but has lower sensitivity. To obtain high specificity and sensitivity, we propose to utilize a vessel-size-sensitive filter to the GE-BOLD signal, which suppresses macrovascular contributions and to combine selectively retained microvascular GE-BOLD signals with the SE-BOLD signals. To investigate our proposed idea, fMRI with 0.8 mm isotropic resolution was performed on the primary motor and sensory cortices in humans at 7 T by implementing spin- and gradient-echo (SAGE) echo planar imaging (EPI) acquisition. Microvascular-passed sigmoidal filters were designed based upon the vessel-size-sensitive ΔR2*/ΔR2 value for retaining GE-BOLD signals originating from venous vessels with ≤ 45 µm and ≤ 65 µm diameter. Unlike GE-BOLD fMRI, the laminar profile of SAGE-BOLD fMRI with the vessel-size-sensitive filter peaked at ∼ 1.0 mm from the surface of the primary motor and sensory cortices, demonstrating an improvement of laminar specificity over GE-BOLD fMRI. Also, the functional sensitivity of SAGE BOLD at middle layers (0.75-1.5 mm) was improved by ∼ 80% to ∼100% when compared with SE BOLD. In summary, we showed that combined GE- and SE-BOLD fMRI with the vessel-size-sensitive filter indeed yielded improved laminar specificity and sensitivity and is therefore an excellent tool for high spatial resolution ultra-high filed (UHF)-fMRI studies for resolving mesoscopic functional units.

The impact of COVID-19 on the patterns of emergency department visits among pediatric patients.

OBJECTIVES: This study aimed to investigate the patterns of pediatric patients visiting emergency departments (EDs) before and after the COVID-19 pandemic and evaluate the interactive effect between the COVID-19 outbreak and age groups. METHODS: We performed a cross-sectional study using the nationwide emergency patient database in Korea from January 2019 to December 2020. Pediatric patients (≤18 years) who visited all 402 nationwide EDs were included. The age- and sex-standardized incidence rates of pediatric ED visits per 1,000,000 person-days were calculated, and the incidence rate ratio (IRR) was calculated. The adjusted odds ratio (aOR) and 95% confidence interval (CI) of in-hospital mortality were calculated by a multivariable logistic regression. RESULTS: Among 2,808,756 patients, 1,835,045 (65.3%) patients visited before COVID-19, and 973,711 (34.7%) patients visited after the COVID-19 period. The standardized incidence rates of ED visits per 1,000,000 person-days were 589.3 in the before COVID-19 group and 326.9 in the after COVID-19 group (IRR (95% CI): 0.55 (0.53-0.58)). By diagnosis, the IRRs (95% CI) of mental health disorders (0.84 (0.42-1.65)) and self-harm or suicidal attempts (0.99 (0.38-2.59) were not significant, while the incidence rate of infectious disease was significantly decreased (0.48 (0.42-0.54)). The aOR (95% CI) of in-hospital mortality after COVID-19 was 1.58 (1.44-1.73) compared to that before COVID-19. CONCLUSIONS: During the COVID-19 pandemic, the incidence of pediatric ED visits decreased, and these effects differed by age group. Age-specific policies are needed to ensure that children receive the care they need at the right time.

Improvement of sensitivity and specificity for laminar BOLD fMRI with double spin-echo EPI in humans at 7 T.

Mapping mesoscopic cortical functional units such as columns or laminae is increasingly pursued by ultra-high field (UHF) functional magnetic resonance imaging (fMRI). The most popular approach for high-resolution fMRI is currently gradient-echo (GE) blood oxygenation level-dependent (BOLD) fMRI. However, its spatial accuracy is reduced due to its sensitivity to draining vessels, including pial veins, whereas spin-echo (SE) BOLD signal is expected to have higher spatial accuracy, albeit with lower sensitivity than the GE-BOLD signal. Here, we introduce a new double spin-echo (dSE) echo-planar imaging (EPI) method to improve the sensitivity of SE-BOLD contrast by averaging two spin-echoes using three radiofrequency pulses. Human fMRI experiments were performed with slices perpendicular to the central sulcus between motor and sensory cortices at 7 T during fist-clenching with touching. First, we evaluated the feasibility of single-shot dSE-EPI for BOLD fMRI with 1.5 mm isotropic resolution and found that dSE-BOLD fMRI has higher signal-to-noise ratio (SNR), temporal SNR (tSNR), and higher functional sensitivity than conventional SE-BOLD fMRI. Second, to investigate the laminar specificity of dSE-BOLD fMRI, we implemented a multi-shot approach to achieve 0.8-mm isotropic resolution with sliding-window reconstruction. Unlike GE-BOLD fMRI, the cortical profile of dSE-BOLD fMRI peaked at ~ 1.0 mm from the surface of the primary motor and sensory cortices, demonstrating an improvement of laminar specificity in humans over GE-BOLD fMRI. The proposed multi-shot dSE-EPI method is viable for high spatial resolution UHF-fMRI studies in the pursuit of resolving mesoscopic functional units.

A multi-inversion multi-echo spin and gradient echo echo planar imaging sequence with low image distortion for rapid quantitative parameter mapping and synthetic image contrasts.

PURPOSE: Brain imaging exams typically take 10-20 min and involve multiple sequential acquisitions. A low-distortion whole-brain echo planar imaging (EPI)-based approach was developed to efficiently encode multiple contrasts in one acquisition, allowing for calculation of quantitative parameter maps and synthetic contrast-weighted images. METHODS: Inversion prepared spin- and gradient-echo EPI was developed with slice-order shuffling across measurements for efficient acquisition with T1 , T2 , and T2∗ weighting. A dictionary-matching approach was used to fit the images to quantitative parameter maps, which in turn were used to create synthetic weighted images with typical clinical contrasts. Dynamic slice-optimized multi-coil shimming with a B0 shim array was used to reduce B0 inhomogeneity and, therefore, image distortion by >50%. Multi-shot EPI was also implemented to minimize distortion and blurring while enabling high in-plane resolution. A low-rank reconstruction approach was used to mitigate errors from shot-to-shot phase variation. RESULTS: The slice-optimized shimming approach was combined with in-plane parallel-imaging acceleration of 4× to enable single-shot EPI with more than eight-fold distortion reduction. The proposed sequence efficiently obtained 40 contrasts across the whole-brain in just over 1 min at 1.2 × 1.2 × 3 mm resolution. The multi-shot variant of the sequence achieved higher in-plane resolution of 1 × 1 × 4 mm with good image quality in 4 min. Derived quantitative maps showed comparable values to conventional mapping methods. CONCLUSION: The approach allows fast whole-brain imaging with quantitative parameter maps and synthetic weighted contrasts. The slice-optimized multi-coil shimming and multi-shot reconstruction approaches result in minimal EPI distortion, giving the sequence the potential to be used in rapid screening applications.

A Systematic Review of Respiratory Sinus Arrhythmia in Romantic Relationships.

Respiratory sinus arrhythmia (RSA), an index of the parasympathetic nervous system, has recently gained attention as a physiological component of regulatory processes, social connectedness, and health. Within the context of romantic relationships, studies have operationalized and conceptualized RSA in disparate ways, obscuring a clear pattern of findings. This systematic review synthesizes the rapidly developing literature and clarifies the role of RSA in romantic relationships. We evaluate support for three conceptual hypotheses: (1) resting baseline RSA is associated with better quality relationships; (2) phasic RSA is reflective of changes in threat and connection during couple interactions; and (3) physiological linkage in RSA between romantic partners relates to positive or negative relationship functioning depending on the nature of the linkage (e.g., in-phase vs. antiphase). We identified 26 empirical studies that tested associations between RSA and an index of romantic relationships (i.e., relationship satisfaction). Our findings show that higher RSA is not uniformly "good" for relationships. Higher resting baseline RSA was contemporaneously associated with better quality relationships, yet higher baseline RSA was also unexpectedly associated with relationship violence. Short-term decreases in RSA were found during relationship conflict, though the opposite-phasic increases in RSA during positive romantic partner interactions-was not found due to mixed empirical support. As expected, evidence for RSA linkage was found, though the connection between linkage and relationship functioning depends on the context in which it was measured. We discuss methodological limitations and directions for future research.

La arritmia sinusal respiratoria (ASR), un índice del sistema nervioso parasimpático, ha sido objeto de atención recientemente como componente fisiológico de los procesos reguladores, la conexión social y la salud. Dentro del contexto de las relaciones amorosas, los estudios han operacionalizado y conceptualizado la ASR de diversas maneras, ocultando un patrón claro de signos. Este análisis sistemático sintetiza la bibliografía que se está desarrollando rápidamente y aclara el papel que desempeña la ASR en las relaciones amorosas. Evaluamos el respaldo de tres hipótesis conceptuales: (1) una ASR de reposo en el momento basal está asociada con relaciones de mejor calidad; (2) la ASR refleja cambios en la amenaza y la conexión durante las interacciones de la pareja; y (3) la asociación fisiológica en la ASR entre los integrantes de la pareja se relaciona con el funcionamiento positivo o negativo de la relación según la índole de la asociación (p. ej.: en fase frente a contrafase). Identificamos 26 estudios empíricos que evaluaron las asociaciones entre la ASR y un índice de las relaciones amorosas (p. ej.: la satisfacción con la relación). Nuestros resultados indican que una ASR más alta no es uniformemente "buena" para las relaciones. Una ASR de reposo más alta en el momento basal estuvo asociada contemporáneamente con relaciones de mejor calidad, sin embargo, una ASR más alta en el momento basal también estuvo asociada inesperadamente con la violencia de pareja. Se encontraron disminuciones de la ASR a corto plazo durante el conflicto en las relaciones, aunque no se encontró lo opuesto -aumentos fásicos en la ASR durante las interacciones positivas de los integrantes de la pareja- debido a un respaldo empírico ambivalente. Como se esperaba, se encontraron indicios de una asociación de la ASR, aunque la conexión entre la asociación y el funcionamiento de la relación depende del contexto en el cual se midió. Comentamos las limitaciones metodológicas y damos indicaciones para investigaciones futuras.

Blood Oxygen Level-Dependent MRI of the Myocardium with Multiecho Gradient-Echo Spin-Echo Imaging.

Background Myocardial oxygenation imaging could help determine the presence of microvascular dysfunction associated with increased cardiovascular risk. However, it is challenging to depict the potentially small oxygenation alterations with current noninvasive cardiac MRI blood oxygen level-dependent (BOLD) techniques. Purpose To demonstrate the cardiac application of a gradient-echo spin-echo (GESE) echo-planar imaging sequence for dynamic and quantitative heartbeat-to-heartbeat BOLD MRI and evaluate the sequence in populations both healthy and with hypertension in combination with a breath hold-induced CO2 intervention. Materials and Methods GESE echo-planar imaging sequence was performed in 18 healthy participants and in eight prospectively recruited participants with hypertension on a 3.0-T MRI system. T2 and T2* maps were calculated per heartbeat with a four-parameter fitting technique. Septal regions of interests were used to determine T2 and T2* values per heartbeat and examined over the course of a breath hold to determine BOLD changes. T2 and T2* changes of healthy participants and participants with hypertension were compared by using a nonparametric Mann-Whitney test. Results GESE echo-planar imaging approach gave spatially stable T2 and T2* maps per heartbeat for healthy participants and participants with hypertension, with mean T2 values of 43 msec ± 5 (standard deviation) and 46 msec ± 9, respectively, and mean T2* values of 28 msec ± 5 and 22 msec ± 5, respectively. The healthy participants exhibited increasing T2 and T2* values over the course of a breath hold with a mean positive slope of 0.2 msec per heartbeat ± 0.1 for T2 and 0.2 msec per heartbeat ± 0.1 for T2*, whereas for participants with hypertension these dynamic T2 and T2* values had a mean negative slope of -0.2 msec per heartbeat ± 0.2 for T2 and -0.1 msec per heartbeat ± 0.2 for T2*. The difference in these mean slopes between healthy participants and participants with hypertension was significant for both T2 (P < .001) and T2* (P < .001). Conclusion Gradient-echo spin-echo echo-planar imaging sequence provided quantitative T2 and T2* maps per heartbeat and enabled dynamic heartbeat-to-heartbeat blood oxygen level-dependent (BOLD)-response imaging by analyzing changes in T2 and T2* over the time of a breath-hold intervention. This approach could identify differences in the BOLD response between healthy participants and participants with hypertension. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Friedrich in this issue.

Accelerated spin-echo functional MRI using multisection excitation by simultaneous spin-echo interleaving (MESSI) with complex-encoded generalized slice dithered enhanced resolution (cgSlider) simultaneous multislice echo-planar imaging.

PURPOSE: Spin-echo functional MRI (SE-fMRI) has the potential to improve spatial specificity when compared with gradient-echo fMRI. However, high spatiotemporal resolution SE-fMRI with large slice-coverage is challenging as SE-fMRI requires a long echo time to generate blood oxygenation level-dependent (BOLD) contrast, leading to long repetition times. The aim of this work is to develop an acquisition method that enhances the slice-coverage of SE-fMRI at high spatiotemporal resolution. THEORY AND METHODS: An acquisition scheme was developed entitled multisection excitation by simultaneous spin-echo interleaving (MESSI) with complex-encoded generalized slice dithered enhanced resolution (cgSlider). MESSI uses the dead-time during the long echo time by interleaving the excitation and readout of 2 slices to enable 2× slice-acceleration, while cgSlider uses the stable temporal background phase in SE-fMRI to encode/decode 2 adjacent slices simultaneously with a "phase-constrained" reconstruction method. The proposed cgSlider-MESSI was also combined with simultaneous multislice (SMS) to achieve further slice-acceleration. This combined approach was used to achieve 1.5-mm isotropic whole-brain SE-fMRI with a temporal resolution of 1.5 s and was evaluated using sensory stimulation and breath-hold tasks at 3T. RESULTS: Compared with conventional SE-SMS, cgSlider-MESSI-SMS provides 4-fold increase in slice-coverage for the same repetition time, with comparable temporal signal-to-noise ratio. Corresponding fMRI activation from cgSlider-MESSI-SMS for both fMRI tasks were consistent with those from conventional SE-SMS. Overall, cgSlider-MESSI-SMS achieved a 32× encoding-acceleration by combining Rinplane × MB × cgSlider × MESSI = 4 × 2 × 2 × 2. CONCLUSION: High-quality, high-resolution whole-brain SE-fMRI was acquired at a short repetition time using cgSlider-MESSI-SMS. This method should be beneficial for high spatiotemporal resolution SE-fMRI studies requiring whole-brain coverage.

Pattern recognition analysis of directional intravoxel incoherent motion MRI in ischemic rodent brains.

This study aimed to demonstrate a reliable automatic segmentation method for independently separating reduced diffusion and decreased perfusion areas in ischemic stroke brains using constrained nonnegative matrix factorization (cNMF) pattern recognition in directional intravoxel incoherent motion MRI (IVIM-MRI). First, the feasibility of cNMF-based segmentation of IVIM signals was investigated in both simulations and in vivo experiments. The cNMF analysis was independently performed for S0 -normalized and scaled (by the difference between the maximum and minimum) IVIM signals, respectively. Segmentations of reduced diffusion (from S0 -normalized IVIM signals) and decreased perfusion (from scaled IVIM signals) areas were performed using the corresponding cNMF pattern weight maps. Second, Monte Carlo simulations were performed for directional IVIM signals to investigate the relationship between the degree of vessel alignment and the direction of the diffusion gradient. Third, directional IVIM-MRI experiments (x, y and z diffusion-gradient directions, 20 b values at 7 T) were performed for normal (n = 4), sacrificed (n = 1, no flow) and ischemic stroke models (n = 4, locally reduced flow). The results showed that automatic segmentation of the hypoperfused lesion using cNMF analysis was more accurate than segmentation using the conventional double-exponential fitting. Consistent with the simulation, the double-exponential pattern of the IVIM signals was particularly strong in white matter and ventricle regions when the directional flows were aligned with the applied diffusion-gradient directions. cNMF analysis of directional IVIM signals allowed robust automated segmentation of white matter, ventricle, vascular and hypoperfused regions in the ischemic brain. In conclusion, directional IVIM signals were simultaneously sensitive to diffusion and aligned flow and were particularly useful for automatically segmenting ischemic lesions via cNMF-based pattern recognition.

Pattern recognition analysis of dynamic susceptibility contrast (DSC)-MRI curves automatically segments tissue areas with intact blood-brain barrier in a rat stroke model: A feasibility and comparison study.

BACKGROUND: The manual segmentation of intact blood-brain barrier (BBB) regions in the stroke brain is cumbersome, due to the coexistence of infarction, large blood vessels, ventricles, and intact BBB regions, specifically in areas with weak signal enhancement following contrast agent injection. HYPOTHESIS: That from dynamic susceptibility contrast (DSC)-MRI alone, without user intervention, regions of weak BBB damage can be segmented based on the leakage-related parameter K 2 and the extent of intact BBB regions, needed to estimate K 2 values, determined. STUDY TYPE: Feasibility. ANIMAL MODEL: Ten female Sprague-Dawley rats (SD, 200-250g) underwent 1-hour middle carotid artery occlusion (MCAO) and 1-day reperfusion. Two SD rats underwent 1-hour MCAO with 3-day and 5-day reperfusion. FIELD STRENGTH/SEQUENCE: 7T; ADC and T1 maps using diffusion-weighted echo planar imaging (EPI) and relaxation enhancement (RARE) with variable repetition time (TR), respectively. dynamic contrast-enhanced (DCE)-MRI using FLASH. DSC-MRI using gradient-echo EPI. ASSESSMENT: Constrained nonnegative matrix factorization (cNMF) was applied to the dynamic ΔR2* -curves of DSC-MRI (<4 min) in a BBB-disrupted rat model. Areas of voxels with intact BBB, classified by automated cNMF analyses, were then used in estimating K 1 and K 2 values, and compared with corresponding values from manually-derived areas. STATISTICAL TESTS: Mean ± standard deviation of ΔT1 -differences between ischemic and healthy areas were displayed with unpaired Student's t-tests. Scatterplots were displayed with slopes and intercepts and Pearson's r values were evaluated between K 2 maps obtained with automatic (cNMF)- and manually-derived regions of interest (ROIs) of the intact BBB region. RESULTS: Mildly BBB-damaged areas (indistinguishable from DCE-MRI (10 min) parameters) were automatically segmented. Areas of voxels with intact BBB, classified by automated cNMF, matched closely the corresponding, manually-derived areas when respective areas were used in estimating K 2 maps (Pearson's r = 0.97, 12 slices). DATA CONCLUSION: Automatic segmentation of short DSC-MRI data alone successfully identified areas with intact and compromised BBB in the stroke brain and compared favorably with manual segmentation. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:1369-1381.

A Matter of the Heart: Daytime Relationship Functioning and Overnight Heart Rate in Young Dating Couples.

BACKGROUND: Although past longitudinal research demonstrates that romantic partners affect one another's health outcomes, considerably less is known about how romantic experiences "get under the skin" in everyday life. PURPOSE: The current study investigated whether young couples' naturally occurring feelings of closeness to and annoyance with each other during waking hours were associated with their overnight cardiovascular activity. METHODS: Participants were 63 heterosexual young adult dating couples (Mage = 23.07). Using ecological momentary assessments, couples reported their hourly feelings of closeness to and annoyance with their partners across 1 day; subsequent overnight heart rate was captured through wearable electrocardiogram biosensors. Actor-partner interdependence models tested whether individuals' overnight heart rate varied as a function of (a) their own daytime feelings of closeness and annoyance (actor effects) and (b) their partner's daytime feelings of closeness and annoyance (partner effects) while controlling for daytime heart rate. RESULTS: Although young adults' feelings of romantic closeness and annoyance were unrelated to their own overnight heart rate (i.e., no actor effects), gender-specific partner effects emerged. Young men's nocturnal heart rate was uniquely predicted by their female partner's daytime relationship feelings. When women felt closer to their partners during the day, men exhibited lower overnight heart rate. When women felt more annoyed with their partners during the day, men exhibited heightened overnight heart rate. CONCLUSIONS: The findings illustrate gender-specific links between couple functioning and physiological arousal in the everyday lives of young dating couples, implicating physiological sensitivity to partner experiences as one potential pathway through which relationships affect health.

Phase-matched virtual coil reconstruction for highly accelerated diffusion echo-planar imaging.

PURPOSE: To propose a virtual coil (VC) acquisition/reconstruction framework to improve highly accelerated single-shot EPI (SS-EPI) and generalized slice dithered enhanced resolution (gSlider) acquisition in high-resolution diffusion imaging (DI). METHODS: For robust VC-GRAPPA reconstruction, a background phase correction scheme was developed to match the image phase of the reference data with the corrupted phase of the accelerated diffusion-weighted data, where the corrupted phase of the diffusion data varies from shot to shot. A Gy prewinding-blip was also added to the EPI acquisition, to create a shifted-ky sampling strategy that allows for better exploitation of VC concept in the reconstruction. To evaluate the performance of the proposed methods, 1.5 mm isotropic whole-brain SS-EPI and 860 µm isotropic whole-brain gSlider-EPI diffusion data were acquired at an acceleration of 8-9 fold. Conventional and VC-GRAPPA reconstructions were performed and compared, and corresponding g-factors were calculated. RESULTS: The proposed VC reconstruction substantially improves the image quality of both SS-EPI and gSlider-EPI, with reduced g-factor noise and reconstruction artifacts when compared to the conventional method. This has enabled high-quality low-noise diffusion imaging to be performed at 8-9 fold acceleration. CONCLUSIONS: The proposed VC acquisition/reconstruction framework improves the reconstruction of DI at high accelerations. The ability to now employ such high accelerations will allow DI with EPI at reduced distortion and faster scan time, which should be beneficial for many clinical and neuroscience applications.

Gradient-echo and spin-echo blood oxygenation level-dependent functional MRI at ultrahigh fields of 9.4 and 15.2 Tesla.

PURPOSE: Sensitivity and specificity of blood oxygenation level-dependent (BOLD) functional MRI (fMRI) is sensitive to magnetic field strength and acquisition methods. We have investigated gradient-echo (GE)- and spin-echo (SE)-BOLD fMRI at ultrahigh fields of 9.4 and 15.2  Tesla. METHODS: BOLD fMRI experiments responding to forepaw stimulation were performed with 3 echo times (TE) at each echo type and B0 in α-chloralose-anesthetized rats. The contralateral forelimb somatosensory region was selected for quantitative analyses. RESULTS: At 9.4 T and 15.2 T, average baseline T2* (n = 9) was 26.6 and 17.1 msec, whereas baseline T2 value (n = 9) was 35.7 and 24.5 msec, respectively. Averaged stimulation-induced ΔR2* was -1.72 s-1 at 9.4 T and -3.09 s-1 at 15.2 T, whereas ΔR2 was -1.19 s-1 at 9.4 T and -1.97 s-1 at 15.2 T. At the optimal TE of tissue T2* or T2 , BOLD percent changes were slightly higher at 15.2 T than at 9.4 T (GE: 7.4% versus 6.4% and SE: 5.7% versus 5.4%). The ΔR2* and ΔR2 ratio of 15.2 T to 9.4 T was 1.8 and 1.66, respectively. The ratio of the macrovessel-containing superficial to microvessel-dominant parenchymal BOLD signal was 1.73 to 1.76 for GE-BOLD versus 1.13 to 1.19 for SE-BOLD, indicating that the SE-BOLD contrast is less sensitive to macrovessels than GE-BOLD. CONCLUSION: SE-BOLD fMRI improves spatial specificity to microvessels compared to GE-BOLD at both fields. BOLD sensitivity is similar at the both fields and can be improved at ultrahigh fields only for thermal-noise-dominant ultrahigh-resolution fMRI.

A new ultrafast 3D gradient echo-based imaging method using quadratic-phase encoding.

PURPOSE: To propose a novel 3D ultrafast gradient echo-based MRI method, dubbed RASE, using quadratic-phase encoding. THEORY AND METHODS: Several characteristics of RASE, including spin behaviors, spatial resolution, SNR, and reduction of susceptibility-induced signal loss, were analytically described. A way of compensating for TE variation was suggested in the quadratic phase-encoding direction. Lemon, in vivo rat and mouse images were demonstrated at 9.4T, including a feasibility study for DCE-MRI as one of promising applications. RESULTS: RASE was successfully demonstrated by lemon and in vivo rat brain imaging, showing a good robustness to field inhomogeneity. Contribution of the quadratic phase to signal enhancement in a range of magnetic susceptibilities was also evaluated by simulation. Taking a geometric mean of 2 phantom data acquired with opposite gradient polarities effectively compensated for the effect of TE variation. Preliminary DCE-MRI results were also presented, showing that RASE could more accurately estimate Gd concentration than FLASH. CONCLUSION: RASE offers a shorter effective TE, having less sensitivity to field inhomogeneity and T2* effects, much less Nyquist ghosting or chemical-shift artifacts than gradient echo EPI (GE-EPI). We highly anticipate that RASE can be an alternative to GE-EPI in many applications, particularly those requiring high spatial and temporal resolutions in a broad volume coverage.

Accelerated whole-brain perfusion imaging using a simultaneous multislice spin-echo and gradient-echo sequence with joint virtual coil reconstruction.

PURPOSE: Dynamic susceptibility contrast imaging requires high temporal sampling, which poses limits on achievable spatial coverage and resolution. Additionally, more encoding-intensive multi-echo acquisitions for quantitative imaging are desired to mitigate contrast leakage effects, which further limits spatial encoding. We present an accelerated sequence that provides whole-brain coverage at an improved spatio-temporal resolution, to allow for dynamic quantitative R2 and R2 * mapping during contrast-enhanced imaging. METHODS: A multi-echo spin and gradient-echo sequence was implemented with simultaneous multislice acquisition. Complementary k-space sampling between repetitions and joint virtual coil reconstruction were used along with a dynamic phase-matching technique to achieve high-quality reconstruction at 9-fold acceleration, which enabled 2 × 2 × 5 mm whole-brain imaging at TR of 1.5 to 1.7 seconds. The multi-echo images from this sequence were fit to achieve quantitative R2 and R2 * maps for each repetition, and subsequently used to find perfusion measures including cerebral blood flow and cerebral blood volume. RESULTS: Images reconstructed using joint virtual coil show improved image quality and g-factor compared with conventional reconstruction methods, resulting in improved quantitative maps with a 9-fold acceleration factor and whole-brain coverage during the dynamic perfusion acquisition. CONCLUSION: The method presented shows the advantage of using a joint virtual coil-GRAPPA reconstruction to allow for high acceleration factors while maintaining reliable image quality for quantitative perfusion mapping, with the potential to improve tumor diagnostics and monitoring.

Day-to-day friends' victimization, aggression perpetration, and morning cortisol activity in late adolescents.

This study investigates bidirectional associations between adolescents' daily experiences of victimization and aggression perpetration within friendships. We investigated (a) across-day associations between victimization and aggression perpetration; (b) morning cortisol activity as a moderator of cross-day victimization and aggression links; and (c) potential sex differences in these patterns. For 4 consecutive days, 99 adolescents (Mage  = 18.06, SD = 1.09, 46 females) reported whether they were victimized by or aggressive toward their friends. On three of these days, adolescents provided three morning saliva samples. Multilevel path analyses showed that across days, victimization and aggression were bidirectionally linked, but only for male adolescents. Additionally, for male adolescents, morning cortisol output (but not morning cortisol increase) moderated the association between victimization and next-day aggression; victimization predicted greater next-day aggression for boys with low, but not high, morning cortisol output. Findings implicate a physiological factor that may modify daily links between victimization and aggression in male adolescent friendships.

Automation of pattern recognition analysis of dynamic contrast-enhanced MRI data to characterize intratumoral vascular heterogeneity.

PURPOSE: To automate dynamic contrast-enhanced MRI (DCE-MRI) data analysis by unsupervised pattern recognition (PR) to enable spatial mapping of intratumoral vascular heterogeneity. METHODS: Three steps were automated. First, the arrival time of the contrast agent at the tumor was determined, including a calculation of the precontrast signal. Second, four criteria-based algorithms for the slice-specific selection of number of patterns (NP) were validated using 109 tumor slices from subcutaneous flank tumors of five different tumor models. The criteria were: half area under the curve, standard deviation thresholding, percent signal enhancement, and signal-to-noise ratio (SNR). The performance of these criteria was assessed by comparing the calculated NP with the visually determined NP. Third, spatial assignment of single patterns and/or pattern mixtures was obtained by way of constrained nonnegative matrix factorization. RESULTS: The determination of the contrast agent arrival time at the tumor slice was successfully automated. For the determination of NP, the SNR-based approach outperformed other selection criteria by agreeing >97% with visual assessment. The spatial localization of single patterns and pattern mixtures, the latter inferring tumor vascular heterogeneity at subpixel spatial resolution, was established successfully by automated assignment from DCE-MRI signal-versus-time curves. CONCLUSION: The PR-based DCE-MRI analysis was successfully automated to spatially map intratumoral vascular heterogeneity. Magn Reson Med 79:1736-1744, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

How discrimination and perspective-taking influence adolescents' attitudes about justice.

Little is known about factors influencing adolescents' justice attitudes. This online study investigates perspective-taking and experiences with discrimination for their associations with adolescents' beliefs about how justice is best served. Participants included 179 ethnically/racially diverse high school students (Mage = 16.67 years; SD = 1.02). Higher perspective-taking was associated with less punitive and more restorative attitudes. Youth reporting more personal and ethnic/racial discrimination experiences endorsed more restorative justice attitudes. Perspective-taking also moderated the associations between reports of family, personal, and religious discrimination and punitive justice attitudes: adolescents reporting higher discrimination showed a stronger inverse relationship between perspective-taking and punitive attitudes. Findings have implications for school and community programs aiming to implement restorative policies, and for adolescents' civic participation.

Temporal resolution improvement of calibration-free dynamic contrast-enhanced MRI with compressed sensing optimized turbo spin echo: The effects of replacing turbo factor with compressed sensing accelerations.

PURPOSE: To enhance the temporal resolution of calibration-free dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) by implementing compressed sensing assisted turbo spin echo (CS-TSE) acquisition. MATERIALS AND METHODS: The dynamic sparse sampling variables including acceleration factor, randomized phase encoding distributions, and reconstruction constraints were retrospectively optimized by minimizing the difference from fully sampled dynamic TSE at 7T. The degree of contrast enhancement and the calibration-free quantification of gadolinium (Gd) concentration were evaluated among fast low-angle shot (FLASH), TSE, and CS-TSE acquisitions with multiple phantoms (0.1-6 mM). The kidney-feeding in vivo arterial input function (AIF) was measured at multiple administration doses (0.1-0.3 mmol/kg) to evaluate the benefit of CS-TSE for quantifying rapidly changing high Gd concentrations in C57BL/6 mice (n = 22). RESULTS: In phantom studies, both calibration-free and calibrated conversions estimated equivalent Gd concentrations for CS-TSE (scatterplot slope = 0.9801, r(2) = 0.9998, P < 0.001). In in vivo studies, 4-fold higher temporal resolution (0.96 sec) of CS-TSE over the corresponding TSE enabled robust measurement of AIF first-pass peak and resulting peak enhancement with CS-TSE were observed, with 1.1439- and 2.1258-fold times higher than those with TSE and FLASH acquisitions, respectively, at the 0.1 mmol/kg dose. Calibration-free estimates of AIF peak concentration with CS-TSE were in good agreement with the calibrated approach at multiple administration doses (scatterplot slope = 0.7800, r(2) = 0.8014, P < 0.001). CONCLUSION: Temporal resolution-improved CS-TSE provides practical subsecond (0.96s) calibration-free dynamic MR quantification of high Gd concentration. J. Magn. Reson. Imaging 2016;44:138-147.