Six‐dimensional quantitative DCE MR Multitasking of the entire abdomen: Method and application to pancreatic ductal adenocarcinoma

Abstract

Purpose: To develop a quantitative DCE MRI technique enabling entire-abdomen coverage, free-breathing acquisition, 1-second temporal resolution, and T 1 -based quantification of contrast agent concentration and kinetic modeling for the characterization of pancreatic ductal adenocarcinoma (PDAC). Methods: Segmented FLASH readouts following saturation-recovery preparation with randomized 3D Cartesian undersampling was used for incoherent data acquisition. MR Multitasking was used to reconstruct 6-dimensional images with 3 spatial dimensions, 1 T 1 recovery dimension for dynamic T 1 quantification, 1 respiratory dimension to resolve respiratory motion, and 1 DCE time dimension to capture the contrast kinetics. Sixteen healthy subjects and 14 patients with pathologically confirmed PDAC were recruited for the in vivo studies, and kinetic parameters v p , K trans , v e , and K ep were evaluated for each subject. Intersession repeatability of Multitasking DCE was assessed in 8 repeat healthy subjects. One-way unbalanced analysis of variance (ANOVA) was performed between control and patient groups. Results:In vivo studies demonstrated that v p , K trans , and K ep of PDAC were significantly lower compared with nontumoral regions in the patient group (P = .002, .003, .004, respectively) and normal pancreas in the control group (P = .011, <.001, <.001, respectively), while v e was significantly higher than nontumoral regions (P < .001) and healthy pancreas (P < .001). The kinetic parameters showed good in vivo repeatability (interclass correlation coefficient: v p , 0.95; K trans , 0.98; v e , 0.96; K ep , 0.99). | 929 WANG et Al. How to cite this article: Wang N, Gaddam S, Wang L, et al. Six-dimensional quantitative DCE MR Multitasking of the entire abdomen: Method and application to pancreatic ductal adenocarcinoma. Magn Reson Med. 2020;84:928-942.

Electrocardiogram-less, free-breathing myocardial extracellular volume fraction mapping in small animals at high heart rates using motion-resolved cardiovascular magnetic resonance multitasking: a feasibility study in a heart failure with preserved ejection fraction rat model

“…The method described here did not include bulk motion compensation, as anesthesia and additional immobilization setup did not result in any apparent bulk motion. However, bulk motion compensation is compatible with the CMR Multitasking framework, as described in [ 39 ], where a translational inter-bin registration to k-space data was applied prior to joint reconstruction. Similar motion compensation could be incorporated into the proposed method if used with different experimental setups more susceptible to bulk motion.…”

Five‐dimensional quantitative low‐dose Multitasking dynamic contrast‐ enhanced MRI: Preliminary study on breast cancer

“…17 The feasibility of dynamic T 1 fitting in MT-DCE has been assessed by numerical simulations, phantom validation, and in vivo study in our previous work. 26,27 The relaxivity rate of Gadavist ranged from 3 to 5 L⋅mmol −1 ⋅s −1 in the literature. 32,[41][42][43] The selection of can lead to different values of CA concentration, but has no effect on the Note: The number of malignant tumors and benign tumors was diagnosed on clinical DCE.…”

“…Axial Cartesian readouts were collected using Gaussian random ordering in both phase‐encoding and partition‐encoding directions. In addition, a projection line in the center k‐space was acquired every eighth readout as training data; these data carry information on multidimensional dynamics and are used to estimate the temporal basis functions in the Multitasking framework 26,27 …”

“…21 Magnetic resonance Multitasking uses a low-rank tensor 22,23 imaging model to exploit the high correlation along and across different image dimensions for a vastly accelerated acquisition, and has been applied to multiparametric mapping 21,24,25 and quantitative DCE in multiple organs. 26,27 However, it has not yet been used to meet the sampling requirements for breast, nor has it been tested with reduced CA dosage. In this work, LD-MT-DCE performs dynamic T 1 mapping with whole-breast coverage at a spatial resolution of 0.9 × 0.9 × 1.1 mm 3 and a temporal resolution of 1.4 seconds in one 10-minute continuous scan, allowing the quantification of CA concentration and kinetic parameters.…”

“…To address these limitations and concerns, we propose a low‐dose Multitasking DCE (LD‐MT‐DCE) technique for breast imaging based on MR Multitasking 21 . Magnetic resonance Multitasking uses a low‐rank tensor 22,23 imaging model to exploit the high correlation along and across different image dimensions for a vastly accelerated acquisition, and has been applied to multiparametric mapping 21,24,25 and quantitative DCE in multiple organs 26,27 . However, it has not yet been used to meet the sampling requirements for breast, nor has it been tested with reduced CA dosage.…”