With the development of various models of pulmonary disease, there is tremendous interest in quantitative regional assessment of pulmonary function. While ventilation imaging has been addressed to a certain extent, perfusion imaging for small animals has not kept pace. In humans and large animals perfusion can be assessed using dynamic contrast-enhanced (DCE) MRI with a single bolus injection of a gadolinium (Gd)-based contrast agent. But the method developed for the clinic cannot be translated directly to image the rodent due to the combined requirements of higher spatial and temporal resolution. This work describes a novel image acquisition technique staggered over multiple, repeatable bolus injections of contrast agent using an automated microinjector, synchronized with image acquisition to achieve dynamic first-pass contrast enhancement in the rat lung. This allows dynamic first-pass imaging that can be used to quantify pulmonary perfusion. Gas exchange between the airspaces and the blood is one of the core functions of the lungs. Matched ventilation and perfusion is essential for effective gas exchange (1). Ventilation/perfusion mismatch occurs during most respiratory diseases, such as chronic obstructive pulmonary disease (COPD), asthma, pulmonary embolism (PE), and pulmonary arterial hypertension (PAH). With a large number of genetic rodent models of pulmonary diseases now available for diseases such as asthma (2), COPD (3), pulmonary hypertension (4), pneumonia (5), and pulmonary fibrosis (6), there is a need to develop robust techniques for quantitative regional assessment of pulmonary function in small animals (7).A number of imaging techniques have been developed over the years to study regional lung function. Pulmonary ventilation/perfusion (V/Q) imaging in humans is traditionally performed using a pair of nuclear scans that use inhaled and injected radioisotopes to assess lung function (8). While this technique has been demonstrated in animals, it is limited by poor spatial and temporal resolution and also requires the administration of radioactive materials.The use of MR for lung imaging has been previously limited due to extremely low proton density and susceptibility-related signal loss. With the development of intrinsic as well as extrinsic contrast agent techniques, MRI is emerging as a choice for high-resolution functional imaging in the lung. While MRI is being developed as an alternative in clinics using hyperpolarized 3 He (9,10) or paramagnetic 15 O (11) for ventilation, and dynamic contrastenhanced (DCE) MRI for perfusion, the technological barriers in developing these methods for small animal imaging have been significant.Most MRI pulmonary imaging methods in the rodent have been developed to demonstrate ventilation (12,13); however, methods for perfusion imaging have remained elusive. Quantitative perfusion imaging in the lungs has been demonstrated in humans, canine, and porcine models (14 -16) by capturing the wash-in and wash-out of a single bolus of contrast agent. Most studies on i...

Japanese macaque encephalomyelitis (JME) is an inflammatory demyelinating disease that occurs spontaneously in a colony of Japanese macaques (JM) at the Oregon National Primate Research Center. Animals with JME display clinical signs resembling multiple sclerosis (MS), and magnetic resonance imaging reveals multiple T2-weighted hyperintensities and gadolinium-enhancing lesions in the central nervous system (CNS). Here we undertook studies to determine if JME possesses features of an immune-mediated disease in the CNS. Comparable to MS, the CNS of animals with JME contain active lesions that express IL-17, CD4+ T cells with Th1 and Th17 phenotypes, CD8+ T cells, and positive CSF findings.

http://radiology.rsnajnls.org/cgi/content/full/2513081550/DC1.

Short-term LGH therapy improves insulin sensitivity without inducing basal lipolysis and had no effect on cortisol metabolism and ectopic fat accumulation in GH-deficient adults. This may reflect an LGH-induced increase in IGF-1 to IGFBP-3 molar ratio exerting insulin-like effects through the abundant muscle IGF-1 receptors, but this hypothesis requires confirmation with further studies.