Therapeutic embolization is a common procedure in interventional radiology. A wide variety of agents are available, and each has its own place and use. Additionally, many new agents have appeared on the market in the past several years. The aim of this review article is to give a brief description of available agents, guide appropriate selection, and familiarize the reader regarding appropriate use and limitations.

TWIST, a basic helix-loop-helix (bHLH) transcription factor that regulates mesodermal development, has been shown to promote tumor cell metastasis and to enhance survival in response to cytotoxic stress. Our analysis of rat C6 glioma cell-derived cDNA revealed TWIST expression, suggesting that the gene may play a role in the genesis and physiology of primary brain tumors. To further delineate a possible oncogenic role for TWIST in the central nervous system (CNS), we analyzed TWIST expression in human gliomas and normal brain by using reverse transcription polymerase chain reaction, Northern blot analysis, in situ hybridization, and immunohistochemistry. TWIST expression was detected in the large majority of human glioma-derived cell lines and human gliomas examined. Levels of TWIST mRNA were associated with the highest grade gliomas, and increased TWIST expression accompanied transition from low grade to high grade in vivo, suggesting a role for TWIST in promoting malignant progression. In accord, elevated TWIST mRNA abundance preceded the spontaneous malignant transformation of cultured mouse astrocytes hemizygous for p53. Overexpression of TWIST protein in a human glioma cell line significantly enhanced tumor cell invasion, a hallmark of high-grade gliomas. These findings support roles for TWIST both in early glial tumorigenesis and subsequent malignant progression. TWIST was also expressed in embryonic and fetal human brain, and in neurons, but not glia, of mature brain, indicating that, in gliomas, TWIST may promote the functions also critical for CNS development or normal neuronal physiology.

We report a case of staged flexor tendon reconstruction using a silicon Hunter tendon rod implant. This implant is placed during the first stage of the two-stage procedure to facilitate formation of a pseudotendon sheath. The implant is removed and the tendon graft placed during the second stage of the procedure. Radiography after the first stage of the procedure assesses healing of concomitant bony injury and evaluates the position and integrity of the tendon implant. It is important that radiologists recognize the Hunter tendon rod implant and understand potential complications when interpretating images in these patients.