Liver imaging with gadolinium contrast enhanced MRI is sometimes not sufficient for a reliable diagnosis of liver lesions. For this reasons, special liver Contrast agents that are targeted to the reticuloendothelial system (RES), have been developed to improve both detection and characterization of liver and spleen lesions. Reticuloendothelial Contrast Agents, as e.g. superparamagnetic iron oxides (SPIO), are taken up by healthy liver tissue but not tumors.
These RES targeted contrast agents provide a prolonged imaging window and enough time for high spatial resolution or multiple breath hold images. Reticuloendothelial contrast agents have an increased sensitivity for the detection of small liver lesions (e.g., metastases), compared with gadolinium enhanced MRI and spiral CT. At higher field strengths with an increased signal to noise ratio the susceptibility effect with iron oxide particles may be enhanced.
Other new agents (Gadobenate Dimeglumine, Gadoxetic Acid) have both an initial extracellular circulation and a delayed liver-specific uptake. Since a considerable part of these contrast agents is excreted in the bile, functional biliary imaging can diagnose biliary anomalies, postoperative bile leaks, and anastomotic strictures. Other agents, such as liposomes (with encapsulated Gd-DTPA) or DOTA complexes are in different development stages.

See also Hepatobiliary Contrast Agents, Gadolinium Oxide, Superparamagnetic Iron Oxide and Liposomes.

(SENSE) A MRI technique for relevant scan time reduction. The spatial information related to the coils of a receiver array are utilized for reducing conventional Fourier encoding. In principle, SENSE can be applied to any imaging sequence and k-space trajectories. However, it is particularly feasible for Cartesian sampling schemes. In 2D Fourier imaging with common Cartesian sampling of k-space sensitivity encoding by means of a receiver array enables to reduce the number of Fourier encoding steps.
SENSE reconstruction without artifacts relies on accurate knowledge of the individual coil sensitivities. For sensitivity assessment, low-resolution, fully Fourier-encoded reference images are required, obtained with each array element and with a body coil.
The major negative point of parallel imaging techniques is that they diminish SNR in proportion to the numbers of reduction factors. R is the factor by which the number of k-space samples is reduced. In standard Fourier imaging reducing the sampling density results in the reduction of the FOV, causing aliasing. In fact, SENSE reconstruction in the Cartesian case is efficiently performed by first creating one such aliased image for each array element using discrete Fourier transformation (DFT).
The next step then is to create a full-FOV image from the set of intermediate images. To achieve this one must undo the signal superposition underlying the fold-over effect. That is, for each pixel in the reduced FOV the signal contributions from a number of positions in the full FOV need to be separated. These positions form a Cartesian grid corresponding to the size of the reduced FOV.
The advantages are especially true for contrast-enhanced MR imaging such as dynamic liver MRI (liver imaging) , 3 dimensional magnetic resonance angiography (3D MRA), and magnetic resonance cholangiopancreaticography (MRCP).
The excellent scan speed of SENSE allows for acquisition of two separate sets of hepatic MR images within the time regarded as the hepatic arterial-phase (double arterial-phase technique) as well as that of multidetector CT.
SENSE can also increase the time efficiency of spatial signal encoding in 3D MRA. With SENSE, even ultrafast (sub second) 4D MRA can be realized.
For MRCP acquisition, high-resolution 3D MRCP images can be constantly provided by SENSE. This is because SENSE resolves the presence of the severe motion artifacts due to longer acquisition time. Longer acquisition time, which results in diminishing image quality, is the greatest problem for 3D MRCP imaging.
In addition, SENSE reduces the train of gradient echoes in combination with a faster k-space traversal per unit time, thereby dramatically improving the image quality of single shot echo planar imaging (i.e. T2 weighted, diffusion weighted imaging).

From GE Healthcare;
The Signa HDx MRI system is GE's leading edge whole body magnetic resonance scanner designed to support high resolution, high signal to noise ratio, and short scan times.
Signa HDx 3.0T offers new technologies like ultra-fast image reconstruction through the new XVRE recon engine, advancements in parallel imaging algorithms and the broadest range of premium applications. The HD applications, PROPELLER (high-quality brain imaging extremely resistant to motion artifacts), TRICKS (contrast-enhanced angiographic vascular lower leg imaging), VIBRANT (for breast MRI), LAVA (high resolution liver imaging with shorter breath holds and better organ coverage) and MR Echo (high-definition cardiac images in real time) offer unique capabilities.

Small particles of ferrite are used as superparamagnetic contrast medium in MR imaging (appearing predominantly dark on MRI). These agents exhibit strong T1 relaxation properties, and due to susceptibility differences to their surroundings also produce a strongly varying local magnetic field, which enhances T2 relaxation to darken the contrast media containing structures.
Superparamagnetic contrast agents are also known by the abbreviation SPIO's (small particle iron oxide or superparamagnetic iron oxide) and USPIO's (ultrasmall particle iron oxide or ultrasmall superparamagnetic iron oxide).
Two types of USPIO will be available on the market as blood pool agents, while SPIO's have been used as darkening contrast agents for liver imaging. As particulate matter they are taken up by the RES. Very small particles of less than 300 nanometers also remain intravascular for a prolonged period of time and thus can serve as blood pool agents.

See also the related poll result: 'The development of contrast agents in MRI is'

From Aurora Imaging Technology, Inc.;
The Aurora® 1.5T Dedicated Breast MRI System with Bilateral SpiralRODEO™ is the first and only FDA approved MRI device designed specifically for breast imaging. The Aurora System, which is already in clinical use at a growing number of leading breast care centers in the US, Europe, got in December 2006 also the approval from the State Food and Drug Administration of the People's Republic of China (SFDA).
'Some of the proprietary and distinguishing features of the Aurora System include: 1) an ellipsoid magnetic shim that provides coverage of both breasts, the chest wall and bilateral axillary lymph nodes; 2) a precision gradient coil with the high linearity required for high resolution spiral reconstruction;; 3) a patient-handling table that provides patient comfort and procedural utility; 4) a fully integrated Interventional System for MRI guided biopsy and localization; and 5) the user-friendly AuroraCADâ„¢ computer-aided image display system designed to improve the accuracy and efficiency of diagnostic interpretations.'