Overall, CTA is an accurate technique for acute mesenteric ischemia diagnosis, with reported sensitivity and specificity as high as 93% to 100% and potential to improve patient survival [1,12,15,25,35,39-41]. CT Abdomen and Pelvis CT of the abdomen and pelvis with intravenous (IV) contrast performed during the venous phase has been less well studied compared with CTA in diagnosing mesenteric ischemia. CT with IV contrast can assess nonvascular findings, major arterial lesions, and mesenteric veins; however, the lack of arterial phase may lead to suboptimal evaluation of the mesenteric arteries compared to CTA [25,42]. Schieda et al [42] showed that CT during portal venous phase identified major arterial lesions, although several diagnostic errors occurred when relying on this phase only. Arterial phase influenced care in 19% of patients compared to portal venous phase alone in one study [25]. Because CT with IV contrast is typically performed with oral contrast as well, this additional step may potentially lead to delay in image acquisition and diagnosis. Therefore, CTA is preferred over CT with IV contrast during venous phase as the initial examination when mesenteric ischemia is suspected. There is a lack of relevant literature regarding the use of CT without IV contrast in the evaluation of acute mesenteric ischemia. Nonvascular findings, such as bowel dilation, wall thickening, mesenteric fluid, pneumatosis, and portomesenteric gas, can be identified with a noncontrast CT; however, these tend to be nonspecific or found in more advanced ischemia with a worse prognosis [40,42]. Blachar et al [43] showed that there was worse performance for CT without IV contrast compared to CT with IV contrast, although this was not statistically significant. However, in the same study, the most significant signs of ischemia, arterial filling defects, and decreased bowel wall enhancement, relied on IV contrast, emphasizing the use of contrast when possible [25,31,43].
Imaging of Mesenteric Ischemia. Overall, CTA is an accurate technique for acute mesenteric ischemia diagnosis, with reported sensitivity and specificity as high as 93% to 100% and potential to improve patient survival [1,12,15,25,35,39-41]. CT Abdomen and Pelvis CT of the abdomen and pelvis with intravenous (IV) contrast performed during the venous phase has been less well studied compared with CTA in diagnosing mesenteric ischemia. CT with IV contrast can assess nonvascular findings, major arterial lesions, and mesenteric veins; however, the lack of arterial phase may lead to suboptimal evaluation of the mesenteric arteries compared to CTA [25,42]. Schieda et al [42] showed that CT during portal venous phase identified major arterial lesions, although several diagnostic errors occurred when relying on this phase only. Arterial phase influenced care in 19% of patients compared to portal venous phase alone in one study [25]. Because CT with IV contrast is typically performed with oral contrast as well, this additional step may potentially lead to delay in image acquisition and diagnosis. Therefore, CTA is preferred over CT with IV contrast during venous phase as the initial examination when mesenteric ischemia is suspected. There is a lack of relevant literature regarding the use of CT without IV contrast in the evaluation of acute mesenteric ischemia. Nonvascular findings, such as bowel dilation, wall thickening, mesenteric fluid, pneumatosis, and portomesenteric gas, can be identified with a noncontrast CT; however, these tend to be nonspecific or found in more advanced ischemia with a worse prognosis [40,42]. Blachar et al [43] showed that there was worse performance for CT without IV contrast compared to CT with IV contrast, although this was not statistically significant. However, in the same study, the most significant signs of ischemia, arterial filling defects, and decreased bowel wall enhancement, relied on IV contrast, emphasizing the use of contrast when possible [25,31,43].