Dwell Time is the primary determinant of noise in the MR image, the time between samplings (sampling interval). Noise is proportional to the square root of the bandwidth and the bandwidth is inversely proportional to the dwell time. A longer dwell time means a lower noise thus a greater signal to noise ratio. This also lengthens the total echo sampling time (longer TE).

Short name: Dy-DOTA-4AmCE, central moiety: Dy2+, contrast effect: T2*enhanced
Dy-DOTA-4AmCE, a macrocyclic complex is characterized by a very slow water exchange, a complex compared with several Dy-DTPA derivatives known for their efficacy as T2 contrast agents at high magnetic fields.

Short name: Dy-TPPS or Ho-TPPS, central moiety: Dy2+Ho2+, contrast effect: negative, high susceptibility
Dy-tetraphenyl-porphyrin sulfonate is a substance under development (preclin.) as a MRI contrast agent with tumor selective uptake for tumor detection and control.

Some dyamides are under preclinical development as intravascular MRI contrast agents for blood flow perfusion.

Short name: Dy-DTPA-BMA, generic name: Sprodyamide, central moiety: Dy2+, contrast effect: T2*enhanced, relaxivity: r1=3.4, r2=3.8, B0=0.47,

Short name: Dy-DTPA, central moiety: Dy2+, contrast effect: T2*enhanced,

Short name: Albumin-(Dy-DTPA)x, central moiety: Dy2+, contrast effect: T2*enhanced.

The range of signal intensities that may need to be distinguished in an image or spectrum or that can be distinguished by the electronic components. If the signal dynamic range is too great, the need to keep the highest intensities from overloading the digitizer may result in the weaker features being lost in the digitization noise. This can be dealt with by using an analog to digital converter with a larger range of sensitivity or by using techniques to reduce the dynamic range, e.g. suppressing the signal from water in order to detect the signal from less abundant compounds.