Introduction The purpose of the study was to evaluate the feasibility of Multiple Arterial-Phase (MA) imaging using TWIST-VIBE for the detection of recurrent HCC by comparing it with the equivalent-to-conventional single arterial phase on 3T. We hypothesized that the use of TWIST-VIBE with 6 hepatic arterial sub-phases allowed for a wider observation window of the hepatic arterial phase and an improved detection of arterial hypervascularization in recurrent HCCs, especially for HCCs with a diameter ≤1cm. Materials and Methods Between Oct 2014 and Apr 2015, 58 patients with possible recurrent HCCs after therapy were imaged using a prototype TWIST-VIBE sequence with a protocol of 6-sub-phases for the arterial phase in one breath-hold. The patient population consisted of 46 individuals (mean age, 62.1±7.78 years; range, 36-78 years; 39 male, 7 female), and a total 201 recurrent HCCs were confirmed by follow-up MRI with enlarged size features or lipoid retention on post TACE un-enhanced CT. All examinations were acquired on a 3T MR scanner (MAGNETOM Skyra, Siemens Healthcare, Erlangen, Germany) with an 18-element body matrix coil and an inbuilt 32-element spine matrix coil. The patients were positioned head first in supine position. A prototype TWIST-VIBE sequence was used for the acquisition of multiple arterial, single portal venous and delayed phases. The other MRI protocols included T1-weighted, T2-weighted and diffusion-weighted imaging. The 3rd/6 arterial phase was used as the equivalent-to-conventional single arterial phase from the perspective of contrast being dominated by the central k-space and its acquisition time being equal to a conventional single arterial phase acquistion[1]. Two experienced radiologists who were aware of the presence of recurrence but blinded to the number and location of recurrent foci of HCC independently evaluated the contrast-enhanced images (arterial phase) in 2 separate sessions being 2 weeks apart to minimize recall bias. The recurrence was confirmed by a consensus agreement of another two experienced radiologists who able to access MRI images and follow-up imaging features. Results Six arterial sub-phases TWIST-VIBE showed a detection rate of 100%, including 61 HCCs with a diameter ≤ 1 cm, 101 with a diameter of 1-2 cm and 39 with a diameter of ≥ 2cm. The detection rate of equivalent-to-conventional single arterial phase alone were (78.7%) 48/61 and (83.6%) 51/61 HCCs with the diameter ≤1 cm, (79.2%) 80/101 and (81.2%) 82/101 with the diameter of 1-2 cm and (89.7%) 35/39 and (87.2%) 34/39 with > 2 cm by readers 1 and 2, respectively. Discussion and Conclusion Precise timing of the hepatic arterial phase is essential for the detection of recurrent HCC. Early detection of recurrence can help in determining the appropriate therapy. Conventional imaging approaches are performed with a single hepatic arterial phase that may be suboptimum for capturing the arterial phase. Currently, several technical approaches for an optimal timing of the hepatic arterial phase are available, including scanning at fixed time points, a pre-scan test bolus or real-time bolus tracking. For the first two approaches however, no consensus has been reached on which vascular reference point to use. Interestingly, 6 arterial sub-phases TWIST-VIBE showed arterial hypervascularization in all the 61 HCCs <2 cm as two example cases shown in Fig.1 and Fig.2. Overall, 6 arterial sub-phases TWIST-VIBE showed higher detection of recurrent HCCs compared with the equivalent-to-conventional single arterial phase exams by providing an optimized wide observation window for tumor vascularity evaluation. This is especially valuable in improving the detection of hypervascular recurrent HCCs with diameters of less than 2cm.