Purpose The objective of this study was to determine local doxorubicin levels surrounding radiopaque drug-eluting beads (DEB) in normal swine liver and kidney following transcatheter arterial chemoembolization (TACE). The influence of bead size (70–150µm or 100–300µm) was compared with regard to tissue penetration and spatial distribution of the bead as well as eventual drug coverage (i.e., amount of tissue exposed to drug). Materials and Methods Radiopaque DEBs were synthesized by suspension polymerization followed by incorporation of iodized oil and doxorubicin. Chemoembolization of swine liver and kidney was performed under fluoroscopic guidance. Three dimensional tissue penetration of image-able DEB was investigated ex vivo with microCT. Drug penetration from the bead surface and drug coverage was evaluated with epi-fluorescence microscopy while cellular localization of doxorubicin was evaluated with confocal microscopy. Necrosis was evaluated with H&E. Results MicroCT demonstrated that 70–150µm DEB were present in more distal arteries and located in a more frequent and homogeneous spatial distribution. Tissue penetration of doxorubicin from the bead appeared similar (~300µm) for both DEBs with a maximum tissue drug concentration at 1hr coinciding with nuclear localization of doxorubicin. The greater spatial frequency of the 70–150µm DEBs resulted in ~2-fold improved drug coverage in kidney. Cellular death is predominantly observed around the DEBs beginning at 8 hr but increased at 24 and 168 hrs. Conclusions Smaller DEBs penetrated further into targeted tissue (macroscopic) with a higher spatial density, resulting in greater and more uniform drug coverage (microscopic) in swine.

Purpose-To develop and characterize radiopaque embolization microspheres capable of in vivo detection with intra-procedural fluoroscopy and CT imaging and to evaluate their spatial distribution inside target tissues during and following transcatheter embolization.Materials and Methods-PVA hydrogel microspheres were loaded with lipiodol and examined for iodine content, stability of loading, and conspicuity with fluoroscopy and CT in vitro. Transcatheter embolization of swine liver and kidney was performed with the radiopaque microspheres and spatial distribution was evaluated with intra-procedural fluoroscopy and CT. Ex vivo evaluation was performed using light microscopy and micro-CT.Results-In vitro analyses demonstrated that radiopaque microspheres could be loaded with sufficient iodine content to be detected with routine fluoroscopy and CT imaging and that such loading was relatively stable. Radiopaque microspheres were visible in vivo with fluoroscopy and CT during transcatheter embolization. CT imaging during embolization procedures demonstrated a dose dependent relationship in the number and size of visualized embolized arteries. Imaging features of radiopaque microsphere distribution inside target tissues correlated well with ex vivo light microscopic and micro-CT evaluation of microsphere distribution.Conclusions-Radiopaque embolization microspheres are visualized during transcatheter embolization with routine intra-procedural fluoroscopy and CT. These radiopaque microspheres provided the three dimensional spatial distribution of embolic material inside target organs during the procedure, and therefore can provide real-time, intra-procedural feedback for the interventional

This paper presents an animal model of alcoholism in which rats were exposed to alcohol by inhalation and were fed a diet that simulated the poor diet of some alcoholics. It is hypothesized that some of the pathophysiological effects of alcohol are related to its effects on essential fatty acid metabolism and composition of vital organs. A diet that contains no 20- and 22-carbon essential fatty acids and has low levels of 18-carbon essential fatty acids was used as a dietary challenge. Addition of a second metabolic challenge, i.e., alcohol, led to loss of tissue polyunsaturates, particularly liver arachidonate. A method of cycling alcohol inhalation for 12 h/d was also presented, which was also shown to lower liver arachidonic acid content.

A number of interrelated factors can affect the precision and accuracy of lung nodule size estimation. To quantify the effect of these factors, we have been conducting phantom CT studies using an anthropomorphic thoracic phantom containing a vasculature insert to which synthetic nodules were inserted or attached. Ten repeat scans were acquired on different multi-detector scanners, using several sets of acquisition and reconstruction protocols and various nodule characteristics (size, shape, density, location). This study design enables both bias and variance analysis for the nodule size estimation task. The resulting database is in the process of becoming publicly available as a resource to facilitate the assessment of lung nodule size estimation methodologies and to enable comparisons between different methods regarding measurement error. This resource complements public databases of clinical data and will contribute towards the development of procedures that will maximize the utility of CT imaging for lung cancer screening and tumor therapy evaluation.