A recent critical review of CT and MRI that was based on reports published between 1997 and 2009 also showed that CT and MRI performed comparably with both modalities showing improvement on more recent studies [29]. Notably, unenhanced CT has poor soft tissue contrast in comparison to MRI and therefore has marginal usefulness during staging. It should also be noted anecdotally, for the reasons given above, that in those institutions with MRI and CT capabilities, CT is typically the more used modality in the setting of staging pancreatic cancer. MRI Many MRI advances have been made in the past several years with regard to robustness of image quality, speed of image acquisition, and resolution in imaging. As noted above, MRI has been reported in a recent study to have a sensitivity of 93% and specificity of 50% to 75% for determination of resectability [11], and studies comparing state-of-the-art CT with state-of-the-art MRI report a similar overall performance [29]. MRI has inherently better soft tissue contrast than unenhanced CT enabling superior visualization of tumor without intravenous (IV) contrast administration. Although we could not identify studies specifically addressing noncontrast MRI staging sensitivity and specificity, MRI is preferable because techniques such as flow sensitive sequences and diffusion- weighted imaging provide valuable information when IV contrast is contraindicated. FDG-PET/CT There is considerable variation in how FDG-PET/CT is performed between institutions, with regard to the presence or absence of IV contrast, the presence or absence of oral contrast, as well as other parameters including slice thickness, and field-of-view. When performed without IV contrast, FDG-PET/CT has the same limitations as unenhanced CT with regard to local staging of the tumor. When performed with IV contrast, images are typically obtained at a single phase of contrast enhancement.
Staging of Pancreatic Ductal Adenocarcinoma. A recent critical review of CT and MRI that was based on reports published between 1997 and 2009 also showed that CT and MRI performed comparably with both modalities showing improvement on more recent studies [29]. Notably, unenhanced CT has poor soft tissue contrast in comparison to MRI and therefore has marginal usefulness during staging. It should also be noted anecdotally, for the reasons given above, that in those institutions with MRI and CT capabilities, CT is typically the more used modality in the setting of staging pancreatic cancer. MRI Many MRI advances have been made in the past several years with regard to robustness of image quality, speed of image acquisition, and resolution in imaging. As noted above, MRI has been reported in a recent study to have a sensitivity of 93% and specificity of 50% to 75% for determination of resectability [11], and studies comparing state-of-the-art CT with state-of-the-art MRI report a similar overall performance [29]. MRI has inherently better soft tissue contrast than unenhanced CT enabling superior visualization of tumor without intravenous (IV) contrast administration. Although we could not identify studies specifically addressing noncontrast MRI staging sensitivity and specificity, MRI is preferable because techniques such as flow sensitive sequences and diffusion- weighted imaging provide valuable information when IV contrast is contraindicated. FDG-PET/CT There is considerable variation in how FDG-PET/CT is performed between institutions, with regard to the presence or absence of IV contrast, the presence or absence of oral contrast, as well as other parameters including slice thickness, and field-of-view. When performed without IV contrast, FDG-PET/CT has the same limitations as unenhanced CT with regard to local staging of the tumor. When performed with IV contrast, images are typically obtained at a single phase of contrast enhancement.