Ziel/Aim To establish the performance of the new ultra-long axial field-of-view (UL-FOV) Siemens
Biograph Vision Quadra and a regular (R-FOV) digital Siemens Biograph Vision 600 PET/CT
system in an intra-patient comparison.
Methodik/Methods 20 patients underwent oncological PET/CT following a single administration of 3.5
MBq/kg 18F-FDG. 10 patients received scans first on a R-FOV system (axial FOV 26.3 cm) at 60
min p.i. in continuous bed motion (1.1 mm/s, equivalent to 2 min/bed position) and
then on an UL-FOV system (axial FOV 106 cm) with one bed position (“vertex to thighs”)
and a total acquisition of 10 minutes in list-mode. A subsequent 10 patients were
then examined with the same parameters, with the first examination on the UL-FOV and
the second exam on the R-FOV system.
Ergebnisse/Results Interim analysis revealed equivalent image quality for the 1 min/bp UL-FOV with the
R-FOV images. At 1.1 mm/s table velocity, the R-FOV would require a 19.4 min examination
time to achieve equivalent anatomical coverage and image quality comparable to 1 min
acquisitions on the UL-FOV. Likewise, equivalence in image quality with the R-FOV
system is obtained with reduction in 90 % in exposure, which would result in a mean
equivalent dose of 0.4 mSv for the PET. Although of lower quality compared to the
R-FOV images, 15s/bp acquisitions on the UL-FOV scanner were sufficient to afford
an appreciation of all pathological lesions.
Schlussfolgerungen/Conclusions Image quality obtained on an UL-FOV scanner were of substantially higher quality
for equivalent total examination time. Protocols for the UL-FOV scanner which deliver
equivalent image quality to a state-of-the art digital R-FOV scanner could include
either shorter effective scan times (1 min versus 19.4 min to obtain equivalent anatomical
coverage and quality) or could be achieved with significant reduction in dose (90 %).
Ultra-fast or ultra-low dose scans can be considered in selected cases.
