Acute necrotizing pancreatitis is a severe form of acute pancreatitis characterized by necrosis in and around the pancreas and is associated with high rates of morbidity and mortality. Although acute interstitial edematous pancreatitis is diagnosed primarily on the basis of signs, symptoms, and laboratory test findings, the diagnosis and severity assessment of acute necrotizing pancreatitis are based in large part on imaging findings. On the basis of the revised Atlanta classification system of 2012, necrotizing pancreatitis is subdivided anatomically into parenchymal, peripancreatic, and combined subtypes, and temporally into clinical early (within 1 week of onset) and late (>1 week after onset) phases. Associated collections are categorized as "acute necrotic" or "walled off" and can be sterile or infected. Imaging, primarily computed tomography and magnetic resonance imaging, plays an essential role in the diagnosis of necrotizing pancreatitis and the identification of complications, including infection, bowel and biliary obstruction, hemorrhage, pseudoaneurysm formation, and venous thrombosis. Imaging is also used to help triage patients and guide both temporizing and definitive management. A "step-up" method for the management of necrotizing pancreatitis that makes use of imaging-guided percutaneous catheter drainage of fluid collections prior to endoscopic or surgical necrosectomy has been shown to improve clinical outcomes. The authors present an algorithmic approach to the care of patients with necrotizing pancreatitis and review the use of imaging and interventional techniques in the diagnosis and management of this pathologic condition.

Each year, more than 250,000 hip fractures occur in the United States, resulting in considerable patient mortality and morbidity. The various types of adult proximal femoral fractures require different treatment strategies that depend on a variety of considerations, including the location, morphologic features, injury mechanism, and stability of the fracture, as well as the patient's age and baseline functional status. The authors discuss femoral head, femoral neck, intertrochanteric, and subtrochanteric fractures in terms of injury mechanisms, specific anatomic and biomechanical features, and important diagnostic and management considerations, including the diagnostic utility of imaging modalities. The authors review clinically important classification systems, such as the Pipkin, Garden, Pauwels, and Evans-Jensen classification systems, with emphasis on differentiating subchondral insufficiency fractures from avascular necrosis of the femoral head and typical subtrochanteric fractures from atypical (often bisphosphonate-related) subtrochanteric fractures. In addition, the authors describe the potential complications and management strategies for each fracture type on the basis of the patient's age and physical condition. A clear understanding of these considerations allows the radiologist to better provide appropriate and relevant diagnostic information and management guidance to the orthopedic surgeon.

Multipotent neuroblasts (NBs) are produced throughout life by neural stem cells in the forebrain subventricular zone (SVZ), and are able to travel long distances to the olfactory bulb. On arrival in the bulb, migrating NBs normally replace olfactory neurons, raising interest in their potential for novel cell replacement therapies in various disease conditions. An understanding of the migratory capabilities of NBs is therefore important, but as yet quantitative in vivo measurement of cell migration has not been possible. In this study, targeted intracerebral injections of iron-oxide particles to the mouse SVZ were used to label resident NBs in situ, and their migration was tracked noninvasively over time with magnetic resonance imaging (MRI). Quantitative intensity metrics were employed to identify labeled cells and to show that cells are able to travel at speeds up to 100 µm/h en route to the olfactory bulb, but that distribution through the olfactory bulb occurs at a much slower rate. In addition, comparison of histological and MRI measures of iron-oxide particle distribution were in excellent agreement. Immunohistochemistry analysis 1-3 weeks after labeling revealed that the majority of labeled cells in the olfactory bulb were immature neurons, although iron-oxide particles were also found in astrocytes and microglia. This work indicates that dynamic measurements of endogenous cell migration can be made with MRI and represents the first in vivo measurement of NB migration rates. The use of MRI in future studies tracking endogenous NB cells will permit a more complete evaluation of their role during homeostasis at various developmental stages and during disease progression.

India ink is an appropriate vehicle for intra-operative marking of a hemiglossectomy cavity. The introduction of myoblast/collagen constructs into the rat hemiglossectomy defect increases the amount of regenerated muscle, results in less scar contracture, and may increase meaningful tongue function.