Abstract: We describe a method for opening the blood-brain barrier (BBB) using ultrasound and preformed microbubbles. With this method, diagnostic or therapeutic agents may be administered to the brain. This method can open a focal region of the BBB and administer agents in a targeted fashion or the method can open large regions (or the entirety) of the brain for more global administration of agents. In one embodiment, the method can be used to administer contrast agents (e.g., agents that increase or decrease the magnetic resonance imaging signal) to the brain and thereby improve the quality or information content of imaging data. In another embodiment, a standard clinical diagnostic ultrasound scanner can be used to open specific regions of the BBB and administer diagnostic or therapeutic agents. Importantly, this invention can open the BBB in a non-destructive/non-invasive fashion, allowing the subject to be awake and suffer no detectable side effects.

Abstract: Noninvasive, MR-compatible methods and systems optically detect mechanical cardiac activity by anatomic (e.g., esophageal) movements. Most preferably, esophageal motion is detected optically and is indicative rhythmic cardiac activities. This esophageal motion may then be detected and used to provide a signal indicative of periods of cardiac activity and inactivity. The signal may be further processed so as to generate a trigger signal that may be input to a MR scanner. In such a manner, MR microscopy may be accomplished to acquire information at a specific phase of the cardiac cycle, for example, in synchrony with periods of cardiac inactivity. Moreover, since mechanical cardiac activity is detected and employed, instead of electrical activity as is employed in conventional techniques, the present invention is immune to electromagnetic interference during MR microscopy. As a result, robust cardiac signals may be monitored and gated during 2-dimensional and 3-dimensional in vivo microscopy.

Abstract: Noninvasive, MR-compatible methods and systems optically detect mechanical cardiac activity by anatomic (e.g., esophageal) movements. Most preferably, esophageal motion is detected optically and is indicative rhythmic cardiac activities. This esophageal motion may then be detected and used to provide a signal indicative of periods of cardiac activity and inactivity. The signal may be further processed so as to generate a trigger signal that may be input to a MR scanner. In such a manner, MR microscopy may be accomplished to acquire information at a specific phase of the cardiac cycle, for example, in synchrony with periods of cardiac inactivity. Moreover, since mechanical cardiac activity is detected and employed, instead of electrical activity as is employed in conventional techniques, the present invention is immune to electromagnetic interference during MR microscopy. As a result, robust cardiac signals may be monitored and gated during 2-dimensional and 3-dimensional in vivo microscopy.

Abstract: Whole body animal specimens (preferably small mammals, such as laboratory rats, mice and the like) may be prepared for enhanced MR microscopy. Preferably, whole body animal specimens may be prepared for magnetic resonance (MR) microscopy by perfusing a mixture of a fixative and a MR contrast agent intravascularly of the animal specimen. The MR contrast agent is preferably a gadolinium compound, while the fixative is preferably formalin. In especially preferred embodiments, methods are provided whereby whole body animal specimens may be prepared for magnetic resonance (MR) microscopy by perfusing a MR contrast agent intravascularly of the animal specimen sequentially (a) into a jugular vein and out a carotid artery of the specimen, (b) into a carotid artery and out a jugular vein of the specimen, (c) into a carotid artery and out a femoral artery of the specimen; and then (d) into a jugular vein and out a femoral vein of the specimens.

Abstract: Nuclear magnetic resonance (NMR) images of a human or animal subject's vascular system are enhanced by injecting a liquid comprised of a biocompatible liquid carrier and a dispersion of hyperpolarized gas microbubbles into the subject, followed by generating an image by NMR representing a spatial distribution of the hyperpolarized gas microbubbles injected into the human or animal subject's vascular system. Preferably, the hyperpolarized gas is Helium-3 and/or Xenon-129. The microbubbles most preferably have a mean diameter of less than about 35 .mu.m.

Abstract: Methods and systems obtain three-dimensional images of object morphology using nuclear magnetic resonance imaging. Most preferably, an object is immersed in a volume of imaging fluid. An image is then generated by nuclear magnetic resonance imaging representative of a spatial distribution of the imaging fluid. The three-dimensional image sequences that are obtained thus represent a contoured outline of the image fluid which conforms to the morphology of the object being imaged. These three-dimensional image sequences are then processed to produce a digital array of the object which may be displayed.