Zu Tao1, Sun Yi2, Wu Dan1, and Zhang Yi1
1Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China, 2MR Collaboration, Siemens Healthcare Ltd., Shanghai, China
1Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, China, 2MR Collaboration, Siemens Healthcare Ltd., Shanghai, China
An auto-calibrated reconstruction method by joint
k-space and image-space parallel imaging (KIPI) is proposed for faster CEST
acquisition. KIPI allows an acceleration factor of up to 8-fold for acquiring
source images and produces image quality close to that of the ground truth.
Figure 4. APTw images of a healthy volunteer
calculated from the source images in Figure 3. a: The APTw images using data acquired with AF=2×2 and ACS data for
all frames were treated as ground truth. b-c:
APTw images reconstructed from GRAPPA (b)
and KIPI (c) using
variably-accelerated data, i.e. AF=2×2
for the +3.5-ppm frame with ACS data and AF=2×4 for the other frames without ACS data. Red arrows indicate severe
artifacts in GRAPPA APTw images (b).
Figure 2. Flowchart for implementing
the KIPI method with variably-sampled frames. A solid rectangle represents
an operation, and a solid rounded rectangle means the input or output data to an
operation. The black triangles highlight the steps of reconstruction results. The
dashed contour above explains the sampling strategy, and the one below shows the
reconstruction pipeline. The k-space reconstruction can use GRAPPA, and the
image-space reconstruction can use SENSE. AF stands for acceleration factor,
and ACS refers to auto-calibration signal.
