Construction of a modified capacitive overlap MR coil for imaging of small animals and objects in a clinical whole-body scanner

Abstract

During the last two decades, there has been an explosive increase in the number of MR investigations involving genetically manipulated mice and rats. Many of the animal studies are performed in a more or less clinical environment, where whole-body MR scanners are the only option available. The quality and acquisition time of MR images have improved with the development of novel RF coil technologies. This communication describes the construction of a small inductively coupled capacitive overlap transmit-receive MR coil for imaging of small animals and objects in a clinical MR scanner. The MR coil presented here is a modified version of the bridged loop-gap coil and consists of two tube-shaped coupled resonance circuits, where the primary circuit partly encapsulates the imaging (secondary) circuit. By rotating the concentric primary coil relative to the secondary coil tuning over a range of several hundred kilohertz is obtained. The coil performance was characterized experimentally by acquiring high-resolution anatomical, diffusion and perfusion MR images as well as the acquisition of proton spectra of a mouse tumour.

Dynamic contrast-enhanced susceptibility-weighted perfusion MRI (DSC-MRI) in a glioma model of the rat brain using a conventional receive-only surface coil with a inner diameter of 47mm at a clinical 1.5T scanner

“…Also they used a different contrast agent (USPIO nanoparticles, Schering). Most tumor studies of rodents using clinical scanners performed DCE-MRI perfusion (Seierstad et al, 2007;Egeland et al, 2006;Muruganandham et al, 2006;Thoeny et al, 2005;Kiessling et al, 2004) with custom made coils for the most part. Our goal was to investigate the feasibility performing DSC-MRI in a rodent model using clinical equipment and routine contrast agent to enable therapy studies without additional tools that has previously been performed for stroke models (Chen et al, 2004(Chen et al, , 2007(Chen et al, , 2008.…”

Early prediction of response to radiotherapy and androgen-deprivation therapy in prostate cancer by repeated functional MRI: a preclinical study

“…Animals were imaged using an MRI mouse coil [23], while the temperature was maintained at 38°C. First, the tumor was localized using axial fast spin-echo (FSE) T2-weighted (T2W) images (echo time (TE eff ) = 85 ms, repetition time (TR) = 4000 ms, echo train length (ETL) = 16, image matrix (IM) = 256 × 256, field-of-view (FOV) = 4 cm, slice thickness (ST) = 2 mm).…”

Liposomal doxorubicin improves radiotherapy response in hypoxic prostate cancer xenografts

“…MRI acquisitions were performed as previously described [26], using a 1.5 T GE Signa LS scanner (GE Medical Systems, Milwaukee, WI), and a dedicated MRI mouse coil [27]. Prior to MRI, a heparinized 24G catheter attached to a cannula containing 0.01 ml/g body weight contrast agent (Dotarem ® , diluted in heparinized saline to 0.06 M) was inserted into the tail vein of the mice.…”