Free-breathing high isotropic resolution quantitative susceptibility mapping (QSM) of liver using 3D multi-echo UTE cones acquisition and respiratory motion-resolved image reconstruction.

PURPOSE: To enable free-breathing and high isotropic resolution liver quantitative susceptibility mapping (QSM) using 3D multi-echo UTE cones acquisition and respiratory motion-resolved image reconstruction. METHODS: Using 3D multi-echo UTE cones MRI, a respiratory motion was estimated from the k-space center of the imaging data. After sorting the k-space data with estimated motion, respiratory motion state-resolved reconstruction was performed for multi-echo data followed by nonlinear least-squares fitting for proton density fat fraction (PDFF), R 2 * $$ {\mathrm{R}}_2^{\ast } $$ , and fat-corrected B0 field maps. PDFF and B0 field maps were subsequently used for QSM reconstruction. The proposed method was compared with motion-averaged (gridding) reconstruction and conventional 3D multi-echo Cartesian MRI in moving gadolinium phantom and in vivo studies. Region of interest (ROI)-based linear regression analysis was performed on these methods to investigate correlations between gadolinium concentration and QSM in the phantom study and between R 2 * $$ {\mathrm{R}}_2^{\ast } $$ and QSM in in vivo study. RESULTS: Cones with motion-resolved reconstruction showed sharper image quality compared to motion-averaged reconstruction with a substantial reduction of motion artifacts in both moving phantom and in vivo studies. For ROI-based linear regression analysis of the phantom study, susceptibility values from cones with motion-resolved reconstruction ( QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.31 × gadolinium mM + $$ \times {\mathrm{gadolinium}}_{\mathrm{mM}}+ $$ 0.05, R 2 $$ {R}^2 $$ = 0.999) and Cartesian without motion ( QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.32 × gadolinium mM + $$ \times {\mathrm{gadolinium}}_{\mathrm{mM}}+ $$ 0.04, R 2 $$ {R}^2 $$ = 1.000) showed linear relationships with gadolinium concentrations and showed good agreement with each other. For in vivo, motion-resolved reconstruction showed higher goodness of fit ( QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.00261 × R 2 s - 1 * - $$ \times {\mathrm{R}}_{2_{{\mathrm{s}}^{-1}}}^{\ast }- $$ 0.524, R 2 $$ {R}^2 $$ = 0.977) compared to motion-averaged reconstruction ( QSM ppm $$ {\mathrm{QSM}}_{\mathrm{ppm}} $$ = 0.0021 × R 2 s - 1 * - $$ \times {\mathrm{R}}_{2_{{\mathrm{s}}^{-1}}}^{\ast }- $$ 0.572, R 2 $$ {R}^2 $$ = 0.723) in ROI-based linear regression analysis between R 2 * $$ {\mathrm{R}}_2^{\ast } $$ and QSM. CONCLUSION: Feasibility of free-breathing liver QSM was demonstrated with motion-resolved 3D multi-echo UTE cones MRI, achieving high isotropic resolution currently unachievable in conventional Cartesian MRI.

Slipped capital femoral epiphyses: A major on-target adverse event associated with FGFR tyrosine kinase inhibitors in pediatric patients.

Fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitors (TKIs) are increasingly being used off label in pediatrics. Long-term safety data are limited, and serious toxicities unique to pediatrics may emerge. In a retrospective analysis of patients less than 18 years of age with recurrent/refractory FGFR altered gliomas treated with FGFR TKIs at MSKCC (n = 7), we observed slipped capital femoral epiphyses in three of seven patients along with increased linear growth velocity. Clinicians should closely monitor bone health and have a low index of suspicion for serious orthopedic complications including slipped capital femoral epiphyses and inform patients of related risks as part of consent when treating with FGFR TKIs.

Imaging of pediatric adrenal tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Adrenal tumors other than neuroblastoma are uncommon in children. The most frequently encountered are adrenocortical carcinoma and pheochromocytoma. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary adrenal malignancy other than neuroblastoma at diagnosis and during follow-up.

Imaging of pediatric pancreas tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary pancreatic tumors in children are rare with an overall age-adjusted incidence of 0.018 new cases per 100,000 pediatric patients. The most prevalent histologic type is the solid pseudopapillary neoplasm, followed by pancreatoblastoma. This paper describes relevant imaging modalities and presents consensus-based recommendations for imaging at diagnosis and follow-up.

Imaging of pediatric ovarian tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Ovarian tumors in children are uncommon. Like those arising in the adult population, they may be broadly divided into germ cell, sex cord, and surface epithelium subtypes; however, germ cell tumors comprise the majority of lesions in children, whereas tumors of surface epithelial origin predominate in adults. Diagnostic workup, including the use of imaging, requires an approach that often differs from that required in an adult. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary ovarian malignancy at diagnosis and during follow-up.

Imaging of pediatric testicular tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Primary intratesticular tumors are uncommon in children, but incidence and risk of malignancy both sharply increase during adolescence. Ultrasound is the mainstay for imaging the primary lesion, and cross-sectional modalities are often required for evaluation of regional or distant disease. However, variations to this approach are dictated by additional clinical and imaging nuances. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary testicular malignancy at diagnosis and during follow-up.

Lumps and bumps: What not to miss.

The evaluation of pediatric patients with subcutaneous nodules remains a diagnostic challenge. Pediatric dermatologists are regularly confronted with patients who have a nonspecific nodule. Though most masses that require evaluation are ultimately benign, the possibility of a more aggressive process, including borderline or malignant neoplasms, underscores the pivotal role of the pediatric dermatologist in recognizing these lesions. The aim of this review is to provide an overview of lumps and bumps that are important to recognize to prevent delay in diagnosis or treatment of a serious underlying condition. Clinical clues that may lead the pediatric dermatologist to have a higher index of suspicion for more aggressive lesions are reviewed. Suggestions for evaluation and workup, as well as tips for the difficult to discern lesion, are proposed.

Growth Hormone Induces Recurrence of Infantile Hemangiomas After Apparent Involution: Evidence of Growth Hormone Receptors in Infantile Hemangioma.

Infantile hemangiomas (IHs) are the most common benign tumor of infancy, characterized by a natural history of early proliferation in the first months of life to eventual involution during childhood, often with residual fibrofatty tissue. Once involution has been achieved, IHs do not typically recur. We present two cases of exogenous growth hormone therapy resulting in the recurrence of IHs in late childhood, supported by radiological, immunohistochemical, in vitro, and in vivo evidence.

Clinical spectrum of capillary malformation-arteriovenous malformation syndrome presenting to a pediatric dermatology practice: a retrospective study.

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM-AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM-AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM-AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.

Martin 'Dick' Wittenborg 1914-1969: a legacy.

The life of Martin H. Wittenborg was short. During his tenure at Boston Children's Hospital, he wrote brilliant papers based on his observations regarding such entities as intestinal malrotation and vascular rings and slings. He wrote about his extensive experience using radiotherapy in the treatment of neuroblastoma and its effects on the growing spine. This article reflects the memories of some of his students, who describe him as a brilliant teacher. His effect on so many and his contributions are all the more remarkable considering the fact that Wittenborg was deaf.

Pediatric Leukemia Roadmaps Are a Guide for Positive Metastatic Bone Sarcoma Trials.

ALL cures require many MRD therapies. This strategy should drive experiments and trials in metastatic bone sarcomas.

Vascular anomalies: hemangiomas and beyond--part 1, Fast-flow lesions.

OBJECTIVE: The purpose of this study was to review the medical literature and the current classification of vascular anomalies to clarify common misconceptions and provide guidance for imaging and treatment. In this first article of a two-part series, we focus on the fast-flow vascular anomalies. CONCLUSION: Nonuniformity of terminology across the medical literature hampers understanding of the vascular anomalies. A familiarity with the classification and biology on which this terminology is based is essential for accurate and precise diagnosis.

Vascular anomalies: hemangiomas and beyond--part 2, Slow-flow lesions.

OBJECTIVE: The purpose of this article is to review the medical literature and the current classification of the vascular anomalies to clarify common misconceptions and provide guidance for imaging and treatment. In this second article of a two-part series, we focus on slow-flow vascular anomalies. CONCLUSION: Nonuniformity of terminology across the medical literature hampers understanding of vascular anomalies. A familiarity with the classification and biology on which it is based are essential for accurate and precise diagnosis.

Transient enhancement of pericardium, peritoneum, soft tissues and perhaps lymphatics after large doses of contrast administration: an overlooked phenomenon?

An infant with complex cyanotic congenital heart disease was recently encountered whose radiographs seemed to show enhancement of pericardium, peritoneal mesothelium and body wall fascial planes without enhancement of the liver or spleen after very large doses of intravenous contrast. Although patterns of postcontrast enhancement have been described previously, this pattern seems to be unique. We report the unusual postcontrast opacification pattern and speculate about its underlying mechanism.

Clinical and imaging experience with COVID-19 in nonvaccinated children with cancer.

Children with COVID-19 fare much better than adults but less is known about children with both COVID-19 and a cancer diagnosis in terms of clinical outcome and imaging. We describe our experience with a cohort of children with COVID-19 and cancer who have undergone medical imaging. We reviewed imaging and recorded clinical data and separated this group into two subgroups - hematologic and solid malignancies. Our observational data show that 1)children with hematologic malignancies may be at higher risk for complications, including death than, those with solid tumors, 2) that pulmonary imaging in the former group more often shows abnormalities and 3) that presence of pulmonary imaging abnormalities may portend an unfavorable outcome.

Is IV contrast necessary for MRI follow-up in children with abdominal neuroblastoma?

PURPOSE: The safety of multiple doses of gadolinium-based MRI IV contrast has recently been called in to question. While the long-term safety is being investigated, here, we seek to determine if there is added value to the use of IV contrast for improving detection of tumoral recurrences in children with a history of abdominal neuroblastoma. METHODS: This is a retrospective review of children who underwent abdominal MRI with gadolinium contrast. One radiologist reviewer determined presence or absence of tumor, both before and after administration of IV contrast material and documented level of confidence when a finding was encountered. Change in reader confidence after the use of contrast was measured and fraction of missed lesions on pre-contrast was calculated. Liver and spleen lesions were documented separately. RESULTS: 453 MRI scans in 110 unique patients were reviewed. 65 patients were documented to have a total of 125 lesions, excluding liver, spleen and bones. There were 23 instances of contrast altering the radiologist's confidence and one lesion was missed without the use of contrast. Among liver and spleen, several hepatic lesions were seen only after contrast, but all were benign lesions. CONCLUSION: In selected patients who are undergoing MRI for neuroblastoma, it may be reasonable to forgo the use of IV contrast.

Emergency room imaging in pediatric patients with cancer: analysis of the spectrum and frequency of imaging modalities and findings in a tertiary cancer center and their relationship with survival.

BACKGROUND: To assess the spectrum and frequency of modalities used for emergency room (ER) imaging and their findings in pediatric cancer patients and assess their relationship with survival. METHODS: Consecutive pediatric cancer patients that underwent imaging during an ER visit at our tertiary cancer center over a 5-year period were retrospectively analyzed. Imaging findings were considered positive when they were relevant to the ER presenting complaint. Imaging positivity was correlated with inpatient admission. Overall survival (OS) was assessed with Kaplan-Meier curves and uni- and multi-variate Cox proportional hazards model was used to identify significant factors associated with OS. RESULTS: Two hundred sixty-one patients (135 males and 126 females; median age 11 years [interquartile range 5-16 years] with 348 visits and a total of 406 imaging studies were included. Common chief complaints were related to the chest (100 [28.7 %]) and fever (99 [28.4 %]). ER imaging was positive in 207 visits (59.5 %), commonly revealing increased metastases (50 [14.4 %]), pneumonia (47 [13.5 %]), and other lung problems (12 [2.9 %]). Positive ER imaging was associated with inpatient admission (69.3 % [133/192] vs. 40.4 % [63/156], p < 0.01). Multivariate survival analysis showed that positive ER imaging (hazard ratio [HR] = 2.35 [95% CI 1.44-3.83, p < 0.01), admission (HR = 1.86 [95% CI 1.17-3.00], p < 0.01), number of ER visits (HR = 3.08 [95% CI 1.62-5.83], p < 0.01 for ≥ 3 visits) were associated with poorer survival. CONCLUSIONS: Imaging was able to delineate the cause for ER visits in children with cancer in over half of the cases. Positive ER imaging was associated with admission and worse survival.

Evidence for defective mesolimbic dopamine exocytosis in obesity-prone rats.

The association between dietary obesity and mesolimbic systems that regulate hedonic aspects of feeding is currently unresolved. In the present study, we examined differences in baseline and stimulated central dopamine levels in obesity-prone (OP) and obesity-resistant (OR) rats. OP rats were hyperphagic and showed a 20% weight gain over OR rats at wk 15 of age, when fed a standard chow diet. This phenotype was associated with a 50% reduction in basal extracellular dopamine, as measured by a microdialysis probe in the nucleus accumbens, a projection site of the mesolimbic dopamine system that has been implicated in food reward. Similar defects were also observed in younger animals (4 wk old). In electrophysiology studies, electrically evoked dopamine release in slice preparations was significantly attenuated in OP rats, not only in the nucleus accumbens but also in additional terminal sites of dopamine neurons such as the accumbens shell, dorsal striatum, and medial prefrontal cortex, suggesting that there may be a widespread dysfunction in mechanisms regulating dopamine release in this obesity model. Moreover, dopamine impairment in OP rats was apparent at birth and associated with changes in expression of several factors regulating dopamine synthesis and release: vesicular monoamine transporter-2, tyrosine hydroxylase, dopamine transporter, and dopamine receptor-2 short-form. Taken together, these results suggest that an attenuated central dopamine system would reduce the hedonic response associated with feeding and induce compensatory hyperphagia, leading to obesity.