Triple arterial phase in the dynamic post-contrastografic MRI study of liver lesions: comparative study

Abstract

The objective of our work was to assess the accuracy in terms of spatial and contrast resolution, respiratory movement
artifacts and synchronization of the “triple arterial phase” (TAP) sequence and compare it with the conventionally
acquired arterial phase (AP). Between June 2021 and September 2021 16 patients underwent liver MRI for
characterization and/or follow-up of focal hepatic lesions, and the TAP sequence was used. With the aim to obtain a
TAP sequence we applied the KEYHOLE technique (modified to 35%) and the CENTRA-Keyhole method (Contrast
Enhanced Timing Robust Angiography) for the K-space sampling, to the basic e-THRIVE sequence. 6/16 patients had
previous MRI examinations performed with the classic single AP. Five radiologists experienced in the interpretation
of liver imaging independently examined MRI studies. They were asked to provide their opinion, by using a qualitative
evaluation scale, on spatial resolution, contrast/noise ratio (CNR), presence of breath-hold artifacts, synchronization
of the TAP and its quality and usefulness for the characterization of liver lesions. The same questions were used for
the evaluation of the 6/16 previous MRI examinations acquired with the conventional AP. For all readers, with TAP,
the synchronization of the arterial study, the spatial resolution, the evaluation of artifacts from incorrect breathhold were deemed good or excellent. The contrast resolution in the TAP was excellent for almost all cases. TAP was
overall judged superior to AP. These preliminary results obtained are promising and require confirmation on a larger
sample study to assess the diagnostic benefit of the TAP.