Purpose or Case Report: The purpose of this exhibit is:
-To discuss the role of DWIBS (diffusion-weighted whole body imaging with background body signal suppression) in the evaluation of pediatric body imaging pathology and to identify common indications for its use
-To review normal DWIBS findings in various body organs and to understand imaging pitfalls
-To provide examples of pathological conditions seen on DWIBS
Methods & Materials: We present cases in which DWIBS was used as part of a body MR study performed at our institution over the last 3 years.
Results: Several cases from our institution are presented to illustrate normal and abnormal findings of DWIBS imaging in children. Pitfalls will be emphasized. Technical aspects of DWIBS and the current role of the method in pediatric body imaging will be discussed.
Conclusions: DWIBS is a promising imaging technique increasingly being used in pediatric patients. The feasibility of free breathing and its relative short scan duration makes it ideal for pediatric patients. DWIBS sequence is performed with heavy diffusion weighting (b = 1000 sec/mm²) and fat suppression using an inversion or chemical shift–selective pre-pulse, such as STIR. Multiple thin axial slices with a high number of signal averages are acquired during free breathing, which is a unique feature making it ideal for its use in children. The axial source DW images may be reconstructed in the coronal plane and the gray scale may be inverted to resemble PET images. This is convenient for analyzing the distribution of primary lesions and their metastases. On DWIBS images there is suppression of background tissues with visualization of only those structures and lesions with low diffusion values. DWIBS aids in neoplasm detection, as these have restricted diffusion and characteristically display high signal with high b-values. DWIBS is also playing an expanding role in the detection of inflammatory processes, in the assessment of multifocal infection and abscess formation, and in monitoring response to treatment.