Songyuan Tang, Presenter: Nothing to Disclose

Zheng Fan, Abstract Co-Author: Nothing to Disclose

Hongyu An DSc, Abstract Co-Author: Nothing to Disclose

Dinggang Shen PhD, Abstract Co-Author: Nothing to Disclose

Duchenne muscular dystrophy (DMD) is one of the most common inherited neuromuscular disorders. Muscular MRI may be used as a non-invasive surrogate marker for following disease progression and monitoring therapeutic effect. We seek to use three-point Dixon MRI as a quantifying measurement to evaluate the severity of DMD since three-point Dixon MRI can separate fat only or water only images, from which the muscle fat percentage can be easily computed. Then, by comparing the fat infiltration within muscles of different regions, we seek to find DMD in early stage. But the water or fat images have serious artifacts if they are directly reconstructed from raw data, and these kinds of images cannot predict DMD correctly. Therefore, we need to develop a post-processing algorithm to obtain high-quality fat and water images.

Our method includes three steps: 1) unwrapping the phase images by three-dimensional unwrapping algorithm; 2) filtering the complex data by a high-pass filter; and 3) separating fat and water images by the three-point Dixon technique. Our method can remove the artifacts effectively and obtain good fat percentage map. In our experiment, a pediatric data (3-year-old male) with early stage DMD is used to evaluate the proposed method. In the early stage of DMD, the fat infiltration occurs in large muscles (vastus lateralis and biceps femoris) prior to small muscles (gracilis muscle and sartorius muscle), and the fat percentage of subcutaneous tissue is larger than those of large and small muscles. Therefore, we selected ROIs in these regions and compared the average of top fat percentage in the ROIs.  

The obtained result is shown in a figure and has been evaluated by experts. The average of top fat percentage in subcutaneous tissue is the largest. Also, the average of top fat percentage in large muscles (vastus lateralis and biceps femoris) is higher than that in small muscles (gracilis muscle and sartorius muscle). This result is consistent with the symptom of the early stage of DMD as mentioned above, which confirms that the patient is in the early stage of DMD. The further evaluation of the performance of our proposed method on large datasets is currently ongoing.  

The result from our study shows the feasibility of using three-point Dixon MRI to assess the severity of subject with DMD.  

 

Tang, S, Fan, Z, An, H, Shen, D, Quantitation of Fat and Water from Three Point Dixon MRI for Duchenne Muscular Dystrophy.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016414.html