QISS (Quiescent Interval Single Shot)

Non CE MRA performed with QISS and TOF due to reduced kidney function.Area of interest was artery poplitea at the level of fossa poplitea.T2, T1, T2* (2.5mm) was also performed. QISS showed higher blood signal compared to TOF. QISS in this case took around 2min (1.5mm) and TOF which was around 5min (0.6mm).

Findings: With T2, T1 and T2* it could look like blood coagulation. From QISS and TOF it might look like an aneurysm or pseudo aneurysm.

The point here is that the recently released package of QISS which is meant for peripheral NON CE MRA, might also be helpful in cases like this.

QISS (Quiescent interval single shot) was first introduced by Edelman et.al in 2010. Its been a WIP package until recently, now available on both 1.5T and 3T. Studies done with QISS has shown promising results. QISS employs initial saturation pulses followed by a 2D single shot balanced steady state free precession readout with a quiescent interval between them. Two saturation pulses are used, one for supressing the background, and the other inferior to the slice for venous suppression. The quiescent interval before the readout allows the inflow of unsaturated arterial spins into the imaging plane. The flow sensitivity of QISS technique is negligible compared to other NON CE MRA such as TOF, native SPACE etc.

Exam done on a Siemens Skyra 3T with Knee 15ch