Fast 3D contrast enhanced MRI of the liver using temporal resolution acceleration with constrained evolution reconstruction

Abstract

Time-resolved imaging is crucial for the accurate diagnosis of liver lesions. Current contrast enhanced liver magnetic resonance imaging acquires a few phases in sequential breath-holds. The image quality is susceptible to bolus timing errors, which could result in missing the critical arterial phase. This impairs the detection of malignant tumors that are supplied primarily by the hepatic artery. In addition, the temporal resolution may be too low to reliably separate the arterial phase from the portal venous phase. In this study, a method called temporal resolution acceleration with constrained evolution reconstruction was developed with three-dimensional volume coverage and high-temporal frame rate. Data is acquired using a stack of spirals sampling trajectory combined with a golden ratio view order using an eight-channel coil array. Temporal frames are reconstructed from vastly undersampled data sets using a nonlinear inverse algorithm assuming that the temporal changes are small at short time intervals. Numerical and phantom experimental validation is presented. Preliminary in vivo results demonstrated high spatial resolution dynamic three-dimensional images of the whole liver with high frame rates, from which numerous subarterial phases could be easily identified retrospectively.

High‐spatial and high‐temporal resolution dynamic contrast‐enhanced perfusion imaging of the liver with time‐resolved three‐dimensional radial MRI

“…Reported spatial resolution is higher than that of our technique (0.94 × 0.94 × 1.8 mm 3 vs. 2.1 mm isotropic); however, temporal resolution is worse (∼8 s vs. 4 s) and coverage is smaller. Temporal resolution acceleration with constrained evolution reconstruction (TRACER) uses a stack of variable‐density spirals with golden ratio view ordering and constrained evolution reconstruction to give better in‐plane resolution than our technique (1.3 mm) but worse through‐plane resolution (5 mm). The temporal fidelity varies with spatial frequency and is based on the assumption that temporal changes are small at short time intervals.…”

Pitfalls in liver MRI: Technical approach to avoiding misdiagnosis and improving image quality

“…With recent technological advances related to parallel imaging, compressed sensing, and view sharing, multiarterial phase (a.k.a., time‐resolved) imaging has been investigated as an alternative option to traditional timing methods . Two or more arterial phases are acquired within a single breath‐hold, thereby increasing the probability of capturing the optimal late arterial phase.…”

Recent advances in 3D time-resolved contrast-enhanced MR angiography

“…Although outside the scope of this article, acquisition techniques for time‐resolved CE‐MRA can be adapted to dynamic contrast‐enhanced (DCE) perfusion imaging, and this is an area of growing interest . Time‐resolved CE‐MRA can be used in many anatomic regions.…”