This work is relevant to an efficient adjustable image contrast within one acquisition.Fat suppression or saturation (FatSat) is widely used in MR imaging applications, which reduces the fat signal and preserves water signal for clinical diagnosis, to emphasize any potential pathological changes. In practice, different degrees of FatSat contrast can be generated by selecting different imaging parameters. However, different radiologists often have different preferences for the amount of FatSat. To provide such variable preferences is not trivial. It typically costs more imaging time to re-acquire another contrast of FatSat image by adjusting protocol parameters. The concept of this work is to provide customized (numerically) adjustable FatSat image contrasts with T1W, T2W and PDW, whenever fat and water images are available without extra scanning time. The concept of this work can be extended to other methods besides the DIXON^1-3 method.Considering a FatSat image, it is essentially a composite of a fat only image and a water only image: FatSat Image = a x Fat Image + b x Water Image [1], where a and b are weighting factors such that a+b=1. With different weighting factors of a and b, image contrast can be manipulated. In this work, we utilize “pure” fat and “pure” water images, which are obtained with only one DIXON acquisition, to form a FatSat image. The contrast of this FatSat image can be continuously varied numerically upon radiologists’ preferences without repeatedly acquiring new contrast image at the cost of imaging time.To prove the concept, a series of T1W, T2W and PDW knee MR images (SAG, COR) from three healthy volunteers were acquired at 3 T (Magnetom Verio, Siemens Healthcare AG, Erlangen, Germany). A two-echo 2D TSE DIXON sequence was used to obtain pure fat and water images^4,5, which were then used to reconstruct different FatSat contrast images based on Eq. [1]. As a reference, a conventional TSE sequence with spectral fat suppression was also performed with strong and weak suppression respectively. For T1W sagittal images with a 15-channel knee coil, identical voxel size (3 x 0.6 x 0.4 mm³), iPAT=2, conventional TSE with spectral FatSat, TR/TE = 700 ms / 24 ms; TSE DIXON = TR/TE = 700 ms /12 ms. For T2W sagittal images with a 8-channel knee coil, identical voxel size (3 x 0.5 x 0.4 mm³), iPAT = 2, conventional TSE with spectral FatSat, TR/TE = 4000 ms / 47 ms; TSE DIXON = TR/TE = 4450 ms /53 ms. For PDW coronal images with a 8-channel knee coil, identical voxel size (3 x 0.4 x 0.4 mm³), iPAT = 2, conventional TSE with spectral FatSat, TR/TE = 3000 ms / 37 ms; TSE DIXON = TR/TE = 3000 ms /39 ms.Figure 1 illustrates examples of T1W sagittal knee images acquired with the conventional TSE sequence for diagnosis of cartilage morphology changes, where the contrasts of weak and strong fat suppression are shown in Figure 1A and Figure 1B, respectively. It should be noted that Figure 1A and Figure 1B were acquired in separate scans. If a different contrast is desired, another additional acquisition needs to be performed. Using the proposed approach, setting a and b differently to combine fat and water images to generate FatSat images with different contrast did not require extra acquisitions. This process can be performed interactively to satisfy different readers’ preferences. In contrast to Figure 1, example composed images with different combinations of a and b are shown in Figure 2. Due to wide bandwidth of excitation RF pulse and reliable phase unwrapping of DIXON acquisition, the composed images (Fig.2) show slightly better homogenous fat suppression effect and conventional spectral fat suppression images (Fig.1).This work presents a feasible and simple method to provide continuously adjustable fat suppression image contrast without repeatedly re-acquiring data with different imaging parameter settings. The data post-processing is simple and fast, and can be user-interactive. Further works of validating this concept in other MSK joints, such as ankle, hip and shoulder are undergoing.