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.

(BLISS) BLISS is a magnetic resonance imaging technique that provides the measurement of two bilateral volumes in a single acquisition. Localized shimming for each volume improves the fat suppression. BLISS is an imaging sequence for sagittal breast MRI studies with high spatial resolution and short scan time.

From Siemens Medical Systems;

FDA cleared and CE Mark 2011.
The Biograph mMR has a fully-integrated design for simultaneous PET/MRI imaging. The dedicated hardware includes solid-state, avalanche photodiode PET detector and adapted, PET-compatible MR coils.
The possibility of truly simultaneous operation allows the acquisition of several magnetic resonance imaging (MRI) sequences during the positron emission tomography (PET) scan, without increasing the examination time.
See also Hybrid Imaging.

With this magnetic resonance angiography technique flowing blood appears dark.
MR black blood techniques have been developed for cardiovascular imaging to improve segmentation of myocardium from the blood pool. Black blood MRA techniques decrease the signal from blood with reference to the myocardium and make it easier to perform cardiac chamber segmentation.
ECG gated spin echo sequences with presaturation pulses for magnetization preparation will show strong intravascular signal loss due to flow effects when appropriate imaging conditions including spatial presaturation are used. The sequence use the flow void effect as blood passes rapidly through the selected slice.
For dark blood preparation, a pair of nonselective and selective 180° inversion pulses are used, followed by a long inversion time to null signal from inflowing blood. A second selective inversion pulse can also be applied with short inversion time to null the fat signal. These in cardiac imaging used black blood techniques are referred to as double inversion recovery T1 measurement turbo spin echo or fast spin echo, and double-inversion recovery STIR.

Blood pool agents (intravascular contrast agents) remain in the blood for a prolonged time compared with conventional contrast agents, which diffuse quickly into the interstitial space. Magnetic resonance angiography (MRA), cardiovascular imaging, or contrast enhanced MRIs are possible over an hour or more. This advantage over conventional MRI contrast media allows also higher resolution MRA of several territories using respiratory or cardiac gating techniques with a single contrast bolus.
Different types of blood pool contrast agents:
Blood pool MRI contrast agents with their longer intravascular circulation can be designed to be targeted to necrotic myocardium, to assess myocardial viability, or tumor directed to provide better diagnostic information for various tumors. A disadvantage of the use of blood pool agents for MRA is that the separation of arteries and veins is more difficult because they are present in both and the overlapping of those vessels is disturbing. This can be solved by e.g. different MIP segmentation algorithms.

See also Necrosis Avid Contrast Agent, Tumor Specific Agents, Feruglose, Gadofosveset Trisodium (Vasovist), Ultrasmall Superparamagnetic Iron Oxide and Contrast Medium.