Contrast-enhanced magnetic resonance imaging (MRI) is a commonly used diagnostic tool. Compared to the standard gadolinium-based contrast agents, ferumoxytol (Feraheme, AMAG Pharmaceuticals, Waltham, MA), used as an alternative contrast medium, is feasible in patients with impaired renal function. Other attractive imaging features of intravenous (IV) ferumoxytol include a prolonged blood pool phase and delayed intracellular uptake. With its unique pharmacological, metabolic and imaging properties, ferumoxytol may play a crucial role in future MR imaging of the central nervous system (CNS), various organs outside the CNS, and the cardiovascular system. Preclinical and clinical studies have demonstrated the overall safety and effectiveness of this novel contrast agent with rarely occurring anaphylactoid reactions. The purpose of this review is to describe the general and organ specific properties of ferumoxytol, as well as the advantages and potential pitfalls associated with its use in MRI. In order to more fully demonstrate the applications of ferumoxytol throughout the body, an imaging atlas was created and is available as supplementary material online.

Intense stress and fear have long been known to give rise to a suppression of pain termed "stressinduced analgesia," mediated by brainstem pain-modulating circuitry, including pain-inhibiting neurons of the rostral ventromedial medulla. However, stress does not invariably suppress pain, and indeed, may exacerbate it. Although there is a growing support for the idea of "stress-induced hyperalgesia," the neurobiological basis for this effect remains almost entirely unknown. Using simultaneous single-cell recording and functional analysis, we show here that stimulation of the dorsomedial nucleus of the hypothalamus, known to be a critical component of central mechanisms mediating neuroendocrine, cardiovascular and thermogenic responses to mild or "emotional" stressors such as air puff, also triggers thermal hyperalgesia by recruiting pain-facilitating neurons, "ON-cells", in the rostral ventromedial medulla. Activity of identified RVM ON-cells, OFF-cells and NEUTRAL cells, nociceptive withdrawalthresholds, rectal temperature, and heart rate were recorded in lightly anesthetized rats. In addition to expected increases in body temperature and heart rate, disinhibition of the DMH induced a robust activation of ON-cells, suppression of OFF-cell firing and behavioral hyperalgesia. Blocking ONcell activation prevented hyperalgesia, but did not interfere with DMH-induced thermogenesis or tachycardia, pointing to differentiation of neural substrates for autonomic and nociceptive modulation within the RVM.These data demonstrate top-down activation of brainstem pain-facilitating neurons, and suggest a possible neural circuit for stress-induced hyperalgesia.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the viral strain that has caused the coronavirus disease 2019 (COVID-19) pandemic, has presented healthcare systems around the world with an unprecedented challenge. In locations with significant rates of viral transmission, social distancing measures and enforced 'lockdowns' are the new 'norm' as governments try to prevent healthcare services from being overwhelmed. However, with these measures have come important challenges for the delivery of existing services for other diseases and conditions. The clinical care of patients with pituitary disorders typically involves a multidisciplinary team, working in concert to deliver timely, often complex, disease investigation and management, including pituitary surgery. COVID-19 has brought about major disruption to such services, limiting access to care and opportunities for testing (both laboratory and radiological), and dramatically reducing the ability to safely undertake transsphenoidal surgery. In the absence of clinical trials to guide management of patients with pituitary disease during the COVID-19 pandemic, herein the Professional Education Committee of the Pituitary Society proposes guidance for continued safe management and care of this population.