(MRI-CA, MRCA) The noninvasive imaging of the coronary arteries using magnetic resonance imaging of the heart.
For cardiac MRI-CA, high performance machines are necessary with minimum 40mT/m and 300μsec slew rate.
2D and 3D acquisition are used for fast gradient echo sequences with techniques for minimizing cardiac and respiratory motion and suppressing the high signal of pericardial fat. The optimal sequences seem to be trueFISP, Balanced FFE or FIESTA with SMASH and SENSE techniques. Respiratory motion is minimized for 3D acquisitions by using respiratory gating, especially using navigator echoes (Navigator Technique) to track diaphragmatic and cardiac movement. Optimization of MR technique can provide mapping of long segments of the coronary arteries.
Blood pool agents are being applied to improve the reliability of coronary MR angiography. The major current clinical indication is the identification of coronary artery anomalies because the diagnostic accuracy's for identifying haemodynamically significant stenoses are variable depending of the image quality.

See also Magnetic Resonance Angiography, and Cardiac MRI.

The contrast agents are either renal or hepatically excreted media, which stay in the intravascular/extracellular tissue compartment. The enhancement in the blood continues for as long as the contrast agent remains in the blood stream.
E.g. Dotarem®, Magnevist®, Omniscan®, ProHance®.

See Contrast Medium, Contrast Agents and Blood Pool Agents.

Short name: Gadofluorine-8 (M), central moiety: Gd2+
Gadofluorine is a substance appropriate for a lymph node specific MRI contrast agent (Bayer Schering Pharma AG) and a blood pool agent with positive enhancement.

See also Blood Pool Agents.

Macromolecular Gd labeled albumins are a new class of contrast agents with a wide range of use e.g., MR angiography, breast MRI, perfusion MRI, Lung perfusion, etc.
Marketed gadolinium-based albumin-bound contrast media are e.g., MultiHance®, and Vasovist™; other prototypes are in development. Malignant tumors often show an increased uptake and metabolism of plasma proteins, especially albumin. Contrast agents with large molecules are delivered to all tissues, but only accumulate in those with leaky vessels by tumor capillaries (tumor neovessels). MRI tumor perfusion studies with Gd labeled albumin can show the success of tumor therapy by quantitative decrease in MR signal of the malignant tissue after therapy compared to before. In addition, the study of tumor sensitivity to a therapy with drug-labeled albumins seems possible.
After renal transplantation, MRI may diagnose albuminuria caused by glomerular disease with an albumin-bound blood pool contrast agent

See also Blood Pool Agents, Intravascular Contrast Agents, Contrast Enhanced MRI.

Short name:(Gd-DTPA)n-dextran, central moiety: Gd2+
Gd-DTPA labeled dextran is a substance that has been tested as a blood pool agent (intravascular MRI contrast agent). Dextran is a polysaccharide and has labeled with 15 Gd-DTPA moieties a higher T1 relaxivity than unbound Gd-DTPA, compared with a high safety level.

See also Intravascular Contrast Agents, Blood Pool Agents.