Cyclen-based chelates can be used as contrast agents for multi-modal imaging of tissue cells. The cyclen-based chelates are preferably polyazamacrocyclic molecules formed from 1,4,7,10 tetraazacyclododecane ("cyclen") having varying chelating ions, phosphoester chains, and light harvesting moieties. By changing the chelating ion, phosphoester chain length and/or the light harvesting moiety different imaging techniques, such as MRI, CT, fluorescence and absorption, x-ray and NIR, may be employed to image the tissue cells. Additionally, the cyclen-based chelates may be conjugated to provide for site-specific delivery of the cyclen-based chelate to the desired tissue cells. The cyclen-based chelates may also be delivered to the tissue cells by attaching the cyclen-based chelates to a polymeric delivery vehicle. Although these cyclen-based chelates have a wide variety of application, the preferred use is for imaging of cancer cells, such as brain cancer, for improving resection of a cancerous tissue.

Fluorescent chelates of lanthanide, terbium, europium and dysprosium with tetraazamacrocyclic compounds are discussed which can be used as fluorescent in vitro or in vivo diagnostic agents. These chelates are tissue specific imaging agents for soft tissue cancers.

A histological staining technique that allows quantification of previously unmeasured parameters involved in surgical arteriovenous malformation (AVM) embolization. The invention allows the evaluation of the polymerization characteristics of various ratios of embolization agents, such as Lipiodol/n-butyl 2-cyanoacrylate (NBCA)/glacial acetic acid (GAA) mixtures, by virtue of a new tissue sample preparation protocol and staining technique. To determine the depth of NBCA penetration within the AVM model and to characterize the polymerization patterns of various mixtures within a model vessel, histologic cross-and longitudinal sections were prepared for microscopy using a new staining method including the use of europium aryl-.beta.-diketone complex and petroleum ether. Paraffin-embedded tissue sections were subjected to the staining protocol to improve differentiation between NBCA and Lipiodol.

A method for detecting and localizing a target tissue within the body in the presence of ambient light in which an optical contrast agent is administered and allowed to become functionally localized within a contrast-labeled target tissue to be diagnosed. A light source is optically coupled to a tissue region potentially containing the contrast-labeled target tissue. A gated light detector is optically coupled to the tissue region and arranged to detect light substantially enriched in target signal as compared to ambient light, where the target signal is light that has passed into the contrast-labeled tissue region and been modified by the contrast agent. A computer receives signals from the detector, and passes these signals to memory for accumulation and storage, and to then to image processing engine for determination of the localization and distribution of the contrast agent. The computer also provides an output signal based upon the localization and distribution of the contrast agent, allowing trace amounts of the target tissue to be detected, located, or imaged. A system for carrying out the method is also described.

A computer-assisted method for detecting surface features in a virtual colonoscopy. The method includes providing a three-dimensional construction of a computed tomography colonography surface; creating a path along the teniae coli from the proximal ascending colon to the distal descending colon on the colonography surface; forming an indexed computed tomography colonography surface using the created path; and registering the supine and prone scans of the computed tomography colonography surface using the indexed computed tomography colonography surface. The method also includes navigating the internal surface of the computed tomography colonography using the indexed computed tomography colonography surface.