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Background: Prostate imaging reporting and data system version 2 (PI-RADS v2) relegates dynamic contrast enhanced (DCE) imaging to a minor role. We sought to determine how often DCE is used in PI-RADS v2 scoring.Materials and Methods: We retrospectively reviewed data from 388 patients who underwent prostate magnetic resonance imaging and subsequent biopsy from January 2016 through December 2017. In accordance with PI-RADS v2, DCE was deemed necessary if a peripheral-zone lesion had a diffusion-weighted imaging score of 3, or if a transition-zone lesion had a T2 score of 3 and diffusion-weighted imaging experienced technical failure. Receiver operating characteristic curve analysis assessed the accuracy of prostate-specific antigen density (PSAD) at different threshold values for differentiating lesions that would be equivocal with noncontrast technique. Accuracy of PSAD was compared to DCE using McNemar's test.Results: Sixty-nine lesions in 62 patients (16%) required DCE for PI-RADS scoring. Biopsy of 10 (14%) of these lesions showed clinically significant cancer (Gleason score ≥7). In the subgroup of patients with equivocal lesions, those with clinically significant cancer had significantly higher PSADs than those with clinically insignificant lesions (means of 0.18 and 0.13 ng/mL/mL, respectively; P= 0.038). In this subgroup, there was no statistical difference in accuracy in determining clinically significant cancer between a PSAD threshold value of 0.13 and DCE (P= 0.25).Conclusions: Only 16% of our patients needed DCE to generate the PI-RADS version 2 score, raising the possibility of limiting the initial screening prostate MRI to a noncontrast exam. PSAD may also be used to further decrease the need for or to replace DCE altogether. [ABSTRACT FROM AUTHOR]

Background: Lymphatic malformations can be challenging to treat. Mainstay interventions including surgery and sclerotherapy are invasive and can result in local recurrence and complications. Objective: We sought to assess the effect of 20 weeks of oral sildenafil on reducing lymphatic malformation volume and symptoms in children. Methods: Seven children (4 boys, 3 girls; ages 13-85 months) with lymphatic malformations were given oral sildenafil for 20 weeks in this open-label study. The volume of the lymphatic malformation was calculated blindly using magnetic resonance imaging performed before and after 20 weeks of sildenafil. Lymphatic malformations were assessed clinically on weeks 4, 12, 20, and 32. Both the physician and parents evaluated the lymphatic malformation in comparison with baseline. Results: Four subjects had a lymphatic malformation volume decrease (1.0%-31.7%). In 2 subjects, despite a lymphatic malformation volume increase (1.1%-3.7%), clinical improvement was noted while on sildenafil. One subject had a 29.6% increase in lymphatic malformation volume and no therapeutic response. Lymphatic malformations of all 6 subjects who experienced a therapeutic response on sildenafil softened and became easily compressible. Adverse events were minimal. Limitations: A randomized controlled trial will be necessary to verify the effects of sildenafil on lymphatic malformations. Conclusions: Sildenafil can reduce lymphatic malformation volume and symptoms in some children. [Copyright &y& Elsevier]

Pediatric body and musculoskeletal MRI has seen tremendous advances over the past few years. These advances have enabled high-quality imaging in even the smallest children and expanded the range of clinical problems amenable to MRI. In this review, we highlight some advances: transition to 3 Tesla, parallel imaging, motion compensation, and new contrast agents. Given the increasing saliency of concerns regarding ionizing radiation from computed tomography, these advances could not be more welcome. [Copyright &y& Elsevier]

An abstract of the article "Aortic pulse wave velocity assessment in CMR: a novel method for transit time estimation," by Antonella Meloni, Heather M. Zymeski, Alessia Pepe, Massimo Lombardi, and John C. Wood is presented.

An abstract of the conference paper "Single breathhold three-dimensional cardiac cine MRI with whole ventricular coverage and retrospective cardiac gating using kat ARC," by Peng Lai and colleagues is presented.

Abstract: Appendicitis is the most common surgical cause of acute abdominal pain in the pediatric population. Several conditions can mimic the clinical presentation of appendicitis, leaving imaging as an essential modality to uncover the etiology, yet under certain circumstances, it can be misleading. Here, we present three cases where findings on multidetector computerized tomography scans supported the diagnosis of appendicitis, yet an alternate cause was found. These cases highlight a particular pitfall of satisfaction of search. [Copyright &y& Elsevier]

Background: Ionizing radiation and cost make ultrasound (US), when available, the first imaging study for the diagnosis of suspected pediatric appendicitis. US is less sensitive and specific than computed tomography (CT) or magnetic resonance imaging (MRI) scans, which are often performed after nondiagnostic US.Objectives: We sought to determine predictors of nondiagnostic US in order to guide efficient ordering of imaging studies.Methods: A prospective cohort study of consecutive patients 4 to 30 years of age with suspected appendicitis took place at an emergency department with access to 24/7 US, MRI, and CT capabilities. Patients with US as their initial study were identified. Clinical (i.e., duration of illness, highest fever, and right lower quadrant pain) and demographic (i.e., age and sex) variables were collected. Body mass index (BMI) was calculated based on Centers for Disease Control and Prevention criteria; BMI >85th percentile was categorized as overweight. Patients were followed until day 7. Univariate and stepwise multivariate logistic regression analysis was performed.Results: Over 3 months, 106 patients had US first for suspected appendicitis; 52 (49%) had nondiagnostic US results. Eighteen patients had appendicitis, and there were no missed cases after discharge. On univariate analysis, male sex, a yearly increase in age, and overweight BMI were associated with nondiagnostic US (p < 0.05). In the multivariate model, only BMI (odds ratio 4.9 [95% CI 2.0-12.2]) and age (odds ratio 1.1 [95% CI 1.02-1.20]) were predictors. Sixty-eight percent of nondiagnostic US results occurred in overweight patients.Conclusion: Overweight and older patients are more likely to have a nondiagnostic US or appendicitis, and it may be more efficient to consider alternatives to US first for these patients. Also, this information about the accuracy of US to diagnose suspected appendicitis may be useful to clinicians who wish to engage in shared decision-making with the parents or guardians of children regarding imaging options for children with acute abdominal pain. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we evaluated a cloud-based platform for cardiac magnetic resonance (CMR) four-dimensional (4D) flow imaging, with fully integrated correction for eddy currents, Maxwell phase effects, and gradient field non-linearity, to quantify forward flow, regurgitation, and peak systolic velocity over the pulmonary artery.Methods: We prospectively recruited 52 adult patients during one-year period from July 2014. The 4D flow and planar (2D) phase-contrast (PC) were acquired during same scanning session, but 4D flow was scanned after injection of a gadolinium-based contrast agent. Eddy-currents were semi-automatically corrected using the web-based software. Flow over pulmonary valve was measured and the 4D flow values were compared against the 2D PC ones.Results: The mean forward flow was 92 (±30) ml/cycle measured with 4D flow and 86 (±29) ml/cycle measured with 2D PC, with a correlation of 0.82 and a mean difference of -6ml/cycle (-41-29). For the regurgitant fraction the correlation was 0.85 with a mean difference of -0.95% (-17-15). Mean peak systolic velocity measured with 4D flow was 92 (±49) cm/s and 108 (±56) cm/s with 2D PC, having a correlation of 0.93 and a mean difference of 16cm/s (-24-55).Conclusion: 4D flow imaging post-processed with an integrated cloud-based application accurately quantifies pulmonary flow. However, it may underestimate the peak systolic velocity. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the safety and feasibility of off-label use of ferumoxytol as an intravenous MRI contrast agents in pediatric patients and young adults. Materials and methods With HIPAA compliance and IRB approval, 86 consecutive patients who had undergone 3 T or 1.5 T MRI with ferumoxytol were retrospectively identified. The blood pressure and heart rate of patients before and after ferumoxytol injection were compared. The overall image quality was evaluated independently by two radiologists with a four-point scale. Interobserver agreement was calculated using weighted kappa statistics. Results The mean ± standard deviation (SD) pre and post-contrast systolic blood pressures (SBP) were 101 ± 18 and 95 ± 20, respectively. There was a statistically significant difference between pre-SBP and post-SBP (P = 0.003). The pre-contrast diastolic blood pressure (DBP) and the post-contrast diastolic blood pressure (DBP) were 60 ± 14 and 51 ± 17, respectively. There was a statistically significant difference between pre-DBP and post-DBP (P < 0.001). The number of patients with SBP and DBP increase, SBP increase and DBP decrease, SBP decrease and DBP increase, SBP and DBP decrease, SBP increase and DBP unchanged were 14 (16%), 9 (10%), 6 (7%), 56 (65%), 1 (1%), respectively. There was moderate agreement on all individual assessments of image quality (kappa = 0.45). Eighty-two of 86 (95.4%) studies were scored 3 or above (at least diagnostic quality) by both readers, with 90% confidence interval of 92–99%. Conclusion Ferumoxytol is effective as an MR contrast agent. In our sample, there was on average a small but clinically insignificant drop in SBP and DBP post-contrast injection. Large, randomized, controlled trials are needed to establish optimal dosing, imaging procedures, and safety monitoring. [ABSTRACT FROM AUTHOR]

Abstract: Balanced steady-state free precession (SSFP) sequences use fully refocused gradient waveforms to achieve a high signal and useful image contrast in short scan times. Despite these strengths, the clinical feasibility of balanced SSFP is still limited both by bright fat signal and by the signal voids that result from off-resonance effects such as field or susceptibility variations. A new method, dual-acquisition phase-sensitive SSFP, combines the signals from two standard balanced SSFP acquisitions to separate fat and water while simultaneously reducing the signal voids. The acquisitions are added in quadrature and then phase corrected using a simple algorithm before fat and water can be identified simply by the sign of the signal. This method is especially useful for applications at high field, where the RF power deposition, spatial resolution requirements and gradient strength limit the minimum repetition times. Finally, dual-acquisition phase-sensitive SSFP can be combined with other magnetization preparation schemes to produce specific image contrast in addition to separating fat and water signals. [Copyright &y& Elsevier]