CT imaging without IV contrast has little value in the diagnosis of inflammatory or metabolic aortic diseases. MRA Chest and Abdomen Contrast-enhanced MRA techniques have evolved with the introduction of k-space and image-based acceleration techniques, higher field strengths, ultra-fast gradients, and the use of 3-D gradient-echo techniques. Double or triple inversion recovery and balanced steady-state free-precession pulse sequences are acquired before applying contrast- enhanced MRA. Additionally, delayed high-resolution T1-weighted images are acquired to assess aortic wall enhancement, especially in the cases of suspected inflammatory or infectious processes. Contrast-enhanced MRI can be particularly useful in the evaluation of inflammatory conditions as it can detect wall enhancement, which is a sign of active Takayasu arteritis [66]. Moreover, a recent meta-analysis reported that the addition of contrast- enhanced sequences improved the sensitivity of MRA in detecting Takayasu arteritis from 79% to 92% [44]. The same study showed that contrast-enhanced MRA outperformed catheter-based angiography. Similarly, contrast- enhanced MRI allows for improved detection of wall enhancement in both GCA [67-70] and Behcet disease [55,71]. For suspected neoplasms, contrast-enhanced MRI may be able to help differentiate between atheromatous plaque and tumor as well as help to delineate extravascular extension [72]. Regarding infection, the utility of contrast- enhanced MRA is similar to that of CTA in its ability to detect aneurysms, edema, perivascular stranding, gas, and disrupted calcifications [50]. MRA without IV contrast has some utility in the diagnosis of inflammatory vascular conditions. For example, one meta-analysis found MRA to be 79% sensitive and 97% specific in the diagnosis of Takayasu arteritis, outperforming catheter-based angiography [44]. MRA without IV contrast is able to identify extracranial Nontraumatic Aortic Disease involvement in GCA [73].
Nontraumatic Aortic Disease. CT imaging without IV contrast has little value in the diagnosis of inflammatory or metabolic aortic diseases. MRA Chest and Abdomen Contrast-enhanced MRA techniques have evolved with the introduction of k-space and image-based acceleration techniques, higher field strengths, ultra-fast gradients, and the use of 3-D gradient-echo techniques. Double or triple inversion recovery and balanced steady-state free-precession pulse sequences are acquired before applying contrast- enhanced MRA. Additionally, delayed high-resolution T1-weighted images are acquired to assess aortic wall enhancement, especially in the cases of suspected inflammatory or infectious processes. Contrast-enhanced MRI can be particularly useful in the evaluation of inflammatory conditions as it can detect wall enhancement, which is a sign of active Takayasu arteritis [66]. Moreover, a recent meta-analysis reported that the addition of contrast- enhanced sequences improved the sensitivity of MRA in detecting Takayasu arteritis from 79% to 92% [44]. The same study showed that contrast-enhanced MRA outperformed catheter-based angiography. Similarly, contrast- enhanced MRI allows for improved detection of wall enhancement in both GCA [67-70] and Behcet disease [55,71]. For suspected neoplasms, contrast-enhanced MRI may be able to help differentiate between atheromatous plaque and tumor as well as help to delineate extravascular extension [72]. Regarding infection, the utility of contrast- enhanced MRA is similar to that of CTA in its ability to detect aneurysms, edema, perivascular stranding, gas, and disrupted calcifications [50]. MRA without IV contrast has some utility in the diagnosis of inflammatory vascular conditions. For example, one meta-analysis found MRA to be 79% sensitive and 97% specific in the diagnosis of Takayasu arteritis, outperforming catheter-based angiography [44]. MRA without IV contrast is able to identify extracranial Nontraumatic Aortic Disease involvement in GCA [73].