Short name: PLLGd-DTPA, generic name: (Gd-DTPA)n-polylysine, chemical compound: Gd-DTPA poly(L-lysine-Gd-diethylenetriamine-N,N,N',N'',N''-pentaacetic acid), central moiety: Gd2+, relaxivity: r1=13.1, B0=0.23T
A polymeric MRI contrast agent under development (preclin., Bayer Schering Pharma AG, Berlin, Germany) with advantages in both MRA and in the differential diagnosis of tumors, particularly in perfusion studies of the myocardium and potential in MR lung perfusion. Dozens of the relatively small molecule Gd-DTPA is bound covalently to polylysine, a large molecular weight backbone. The stable, highly water-soluble agent does not diffuse through the endothelium of the vascular system; it is subject to renal elimination.

Special imaging primarily means advanced MRI techniques used for qualitative and quantitative measurement of biological metabolism as e.g., spectroscopy, perfusion imaging (PWI, ASL), diffusion weighted imaging (DWI, DTI, DTT) and brain function (BOLD, fMRI). This physiological magnetic resonance techniques offer insights into brain structure, function, and metabolism.
Spectroscopy provides functional information related to identification and quantification of e.g. brain metabolites. MR perfusion imaging has applications in stroke, trauma, and brain neoplasm. MRI provides the high spatial and temporal resolution needed to measure blood flow to the brain. arterial spin labeling techniques utilize the intrinsic protons of blood and brain tissue, labeled by special preparation pulses, rather than exogenous tracers injected into the blood.
MR diffusion tensor imaging characterizes the ability of water to spread across the brain in different directions. Diffusion parallel to nerve fibers has been shown to be greater than diffusion in the perpendicular direction. This provides a tool to study in vivo fiber connectivity in brain MRI.
FMRI allows the detection of a functional activation in the brain because cortical activity is intimately related to local metabolism changes.

See also Diffusion Tensor Tractography.

The mobile intraoperative iMotion system produces real-time images used for MR guided surgery and offers functional magnetic resonance imaging, MR spectroscopy, perfusion imaging, and diffusion weighted imaging capabilities.
The iMotion 1.5 T magnet moves to the patient, gliding in and out of place as needed, without affecting surgical, anesthetic, and nursing management.

See also Intraoperative Magnetic Resonance Imaging, MR Guided Interventions.

Short name: B22956, generic name: Gadocoletic acid, chemical compound: Gadocoletic acid trisodium salt, central moiety: Gd, phase: II
A blood pool agent for magnetic resonance coronary angiography and first pass myocardial perfusion imaging under development (Bracco Diagnostics Inc). The small molecules of gadolinium-based B22956 are bound after injection to large human serum albumin molecules in coronary vessels with the result of high vessel/muscle contrast.

Brain imaging, magnetic resonance imaging of the head or skull, cranial magnetic resonance tomography (MRT), neurological MRI - they describe all the same radiological imaging technique for medical diagnostic.
Magnetic resonance imaging of the human brain includes the anatomic description and the detection of lesions. Special techniques like diffusion weighted imaging, functional magnetic resonance imaging (fMRI) and spectroscopy provide also information about the function and chemical metabolites of the brain. MRI provides detailed pictures of brain and nerve tissues in multiple planes without obstruction by overlying bones. Brain MRI is the procedure of choice for most brain disorders. It provides clear images of the brainstem and posterior brain, which are difficult to view on a CT scan. It is also useful for the diagnosis of demyelinating disorders (disorders such as multiple sclerosis (MS) that cause destruction of the myelin sheath of the nerve).
With this noninvasive procedure also the evaluation of blood flow and the flow of cerebrospinal fluid (CSF) is possible. Different MRA methods, also without contrast agents can show a venous or arterial angiogram. MRI can distinguish tumors, inflammatory lesions, and other pathologies from the normal brain anatomy. However, MRI scans are also used instead other methods to avoid the dangers of interventional procedures like angiography (DSA - digital subtraction angiography) as well as of repeated exposure to radiation as required for computed tomography (CT) and other X-ray examinations.
A (birdcage) bird cage coil achieves uniform excitation and reception and is commonly used to study the brain. Usually a brain MRI procedure includes FLAIR, T2 weighted and T1 weighted sequences in two or three planes.

See also Fetal MRI, Fluid Attenuation Inversion Recovery (FLAIR), Perfusion Imaging and High Field MRI.
See also Arterial Spin Labeling.