Diffusion Weighted Imaging: Continued Progress

The article by Yang et al. of Chengdu, China, reviews recent advances in MR techniques relevant to diffusion-weighted imaging of the abdomen, a challenging task still despite the long history of generating diffusion-weighted images ( 1 Yang T. Li Y. Ye Z. Yao S Li Q Yuan Y. Song B. Diffusion weighted imaging of the abdomen and pelvis: Recent technical advances and clinical applications. Academic Radiology. 2023; 30: 470-482https://doi.org/10.1016/j.acra.2022.07.018 Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar ). The article also provides some relevant clinical applications which have benefited from the advances. An article from 10 years ago by Schmid-Tannwald et al provides a snapshot of the field then and offers more detailed organ/disease-specific information than the current article whose focus is on more recent technical developments and vendor implementations to improve high b-image quality ( 2 Schmid-Tannwald C Oto A Reiser MF Zech CJ Diffusion-weighted MRI of the abdomen: current value in clinical routine. J Magn Reson Imag. 2013; 37: 35-47 Crossref PubMed Scopus (41) Google Scholar ). This indeed is the jewel in the crown to be polished by the advances in MR hardware and software discussed by the authors, the “high-b image,” which is prudent as these images are often what many radiologists rely upon when reviewing, for example, prostate images. They quickly turn to the high b-images for assessing suspicious regions, looking for any “lightbulbs” on the high b-images as a consequence of the “restricted diffusion” of water within small cancer cells vs the less restricted water in neighboring healthy tissue. This essential task comprises, I believe, one of the pillars of the most current PI-RADS recommendations for prostate cancer evaluation. Of course, any such “lightbulb” must be gleaned from a set of lower spatial resolution images than accompanying T2-weighted images acquired with modern variations of the FSE/TSE family-based, unlike EPI, on spin vs gradient echo train readouts. The latter explains the often blurry and artifact-laden high-b images that radiologists must deal with when reading abdominal and pelvic MR exams. Arguably, the high b images generated today look better than they did 10 to 15 years ago and much of that improvement can be traced to the developments discussed by Yang et al, developments we now turn to in the order presented by the authors.