High-Resolution, High b-Value Computed Diffusion-Weighted Imaging Improves Detection of Pancreatic Ductal Adenocarcinoma

SIMPLE SUMMARY: High b-value diffusion-weighted imaging (DWI) has shown benefits in the diagnostic workup of pancreatic ductal adenocarcinoma (PDAC). However, technical and practical limitations restrict its widespread application in clinical routine. To overcome these limitations, computed high b-value DWI (cDWI) has been proposed, although there is a potential drawback of lower image quality. Recently, high-resolution (i.e., reduced field-of-view, rFOV) DWI has been proposed to ameliorate image quality and lesion detection in PDAC. We investigated the potential of combining high-resolution and computed high b-value DWI (r-cDWI) for the visualization of PDAC at a b-value of 1000 s/mm(2). We found that the r-cDWI1000 outperformed both conventional computed (i.e., full field-of-view, fFOV) and acquired high-resolution DWI (f-aDWI1000 and r-aDWI1000) in the visualization of PDAC. Our results indicate the potential clinical benefits of high-resolution, high b-value computed DWI in PDAC imaging through enhanced lesion detection and reduced acquisition time. ABSTRACT: Background: Our purpose was to investigate the potential of high-resolution, high b-value computed DWI (cDWI) in pancreatic ductal adenocarcinoma (PDAC) detection. Materials and Methods: We retrospectively enrolled 44 patients with confirmed PDAC. Respiratory-triggered, diffusion-weighted, single-shot echo-planar imaging (ss-EPI) with both conventional (i.e., full field-of-view, 3 × 3 × 4 mm voxel size, b = 0, 50, 300, 600 s/mm(2)) and high-resolution (i.e., reduced field-of-view, 2.5 × 2.5 × 3 mm voxel size, b = 0, 50, 300, 600, 1000 s/mm(2)) imaging was performed for suspected PDAC. cDWI datasets at b = 1000 s/mm(2) were generated for the conventional and high-resolution datasets. Three radiologists were asked to subjectively rate (on a Likert scale of 1–4) the following metrics: image quality, lesion detection and delineation, and lesion-to-pancreas intensity relation. Furthermore, the following quantitative image parameters were assessed: apparent signal-to-noise ratio (aSNR), contrast-to-noise ratio (aCNR), and lesion-to-pancreas contrast ratio (CR). Results: High-resolution, high b-value computed DWI (r-cDWI1000) enabled significant improvement in lesion detection and a higher incidence of a high lesion-to-pancreas intensity relation (type 1, clear hyperintense) compared to conventional high b-value computed and high-resolution high b-value acquired DWI (f-cDWI1000 and r-aDWI1000, respectively). Image quality was rated inferior in the r-cDWI1000 datasets compared to r-aDWI1000. Furthermore, the aCNR and CR were higher in the r-cDWI1000 datasets than in f-cDWI1000 and r-aDWI1000. Conclusion: High-resolution, high b-value computed DWI provides significantly better visualization of PDAC compared to the conventional high b-value computed and high-resolution high b-value images acquired by DWI.