Pancreatic dual-source dual-energy CT: Is it time to discard unenhanced imaging?

Pilot Study: Evaluation of Dual-Energy Computed Tomography Measurement Strategies for Positron Emission Tomography Correlation in Pancreatic Adenocarcinoma

“…In other words, analysis using combinations of multiple imaging variables correlated with PET better than using only single variables such as iodine values or a 70-keV monochromatic Hounsfield unit. However, our results were different from those of a prior study of DECT and PET in small cell lung cancer [10] that found a univariate correlation (r=0.88) between SUV max and iodine-related enhancement (equivalent to an iodine-water basis pair). One explanation may be the lower SUVs in pancreatic cancers (mean, 5 [our study]), whereas the aforementioned lung cancer study reported a high mean SUV of 14.…”

“…Scanning at different radiographic energies facilitates differentiation of materials such as calcium, uric acid, iodine, and water, which can be helpful in various clinical applications (e.g., evaluating renal stone composition [6,7] or differentiating cysts from solid tumors [8]). Specifically, in cases of PA, DECT has shown excellent differentiation of tumors from normal pancreas [9], and it may even allow for the elimination of noncontrast acquisition [10]; the DECT technology, by separating out the iodineloaded images, allows one to generate a "virtual noncontrast" image. Intravenous contrast is still necessary.…”

Evaluation of Virtual Noncontrast Images Obtained from Dual-Energy CTA for Diagnosing Subarachnoid Hemorrhage

“…6 VNC images had been studied primarily in the abdominal aorta and in patients after endovascular repair. 12 To date, many studies of the clinical application of VNC images have been performed, mainly in the abdomen for characterizing renal masses, 13 applications in pancreatic CT, 14 and detecting urinary or biliary stones. 15,16 Most of those studies proved that VNC images were useful and feasible, though the imaging quality was inferior to that in the TNC images.…”

Pancreas

“…This study also showed that a radiation dose saving of about 27 % can be achieved if standard unenhanced images are omitted (Fig. 7.18) [59].…”

“…A calculated mean radiation dose saving of 14 % was achieved if the standard unenhanced dataset was omitted [58]. Another study [59] showed that virtual unenhanced images from a dualenergy dataset acquired during the pancreatic parenchymal phase demonstrated no significant difference in image quality and provided less image noise than true unenhanced imaging. This study also showed that a radiation dose saving of about 27 % can be achieved if standard unenhanced images are omitted (Fig.…”