DAB-Am64-(1B4M-Gd)64 is a new macromolecular MRI contrast agent for the diagnosis of liver micro-metastasis, consisting of a polypropylenimine diaminobutane (DAB) dendrimer conjugated with a bifunctional DTPA derivative complexing Gd(III).

(DQA) This MRI scan or MRI procedure is used by system operators to verify system operation based on relevant image quality parameters like e.g., SNR, slice thickness, geometric distortion, slice position, image resolution and ghosting.
The quality assurance should carry out according to instructions of the manufacturer, normally using the head coil. In addition, SNR can be measured monthly on a selection of commonly used coils. Weekly recording of these parameters is recommended for clinical MRI machines, as this allows early detecting of deviations from acceptable limits.

See Black Boundary Artifact.

The time required to carry out a MR imaging. The total image acquisition time will be equal to the product of repetition time (TR), number of signals averaged (NSA), and the number of different signals (encoded for position) to be acquired for use in image reconstruction. The additional image reconstruction time will also be important to determine how quickly the image can be viewed. In comparing sequential plane imaging and volume imaging techniques, the equivalent image acquisition time per slice must be considered as well as the actual image acquisition time.

Data clipping artifacts give images a washed-out, non-uniform appearance. If the receiver gain increase, so that the signal level is larger than the maximum ADC value, the reconstructed image brightness was scaled to compensate this. The overall intensity loss as well as the extensive signal is reconstructed outside of the object. This effect is called 'clipping' because on a plot of signal amplitude vs. time, it looks like the top and bottom of the echo has been 'clipped off' with scissors.

See Radio Frequency Overflow Artifact.