Assessment of aorto‐iliac disease with magnetic resonance angiography using arterial phase 3‐d gradient‐echo and interstitial phase 2‐d fat‐suppressed spoiled gradient‐echo sequences

Abstract

Purpose: To evaluate magnetic resonance angiography (MRA) of the pelvis for the examination of the aorto-iliac system using arterial phase 3-D gradient echo and interstitial phase 2-D fat-suppressed spoiled gradient-echo (SGE), with comparison to surgery and angiography. Materials and Methods:Ninety MR angiograms performed on 79 consecutive patients were analyzed, retrospectively, for the presence of narrowing, aneurysm, and dissection. Comparisons were made with angiography and surgery in 50 examinations, and a weighted kappa statistic test was applied to assess agreement. MR examinations were performed at 1.5T 3-D fast imaging in steady state precession (FISP) acquired immediately, and fat-suppressed SGE in the interstitial phase following gadolinium administration.Results: MRA had overall sensitivities of 100% at aortic segments, 100% at common iliac, 93.8% at external, and 95.7% at internal iliac, and specificities of 100% at aortic segments, 89.7% at common iliac, 95.2% at external iliac, and 88.7% at internal iliac in detection of vascular disease. The agreement of MRA with the angiography and surgery yielded a weighted kappa statistic of 0.97 at the aortic, 0.94 at the common, 0.85 at the external, and 0.82 at the internal iliac segments. Conclusion:This study demonstrates an excellent performance of MRA in the evaluation of aorto-iliac arterial system and almost perfect agreement with angiography and surgery at all vascular levels.

Abdominal and Iliac Arterial Stenoses: Comparative Double-blinded Randomized Study of Diagnostic Accuracy of 3D MR Angiography with Gadodiamide or Gadopentetate Dimeglumine

“…The investigators in other clinical studies injected contrast agents at doses between 0.2 and 0.3 mmol/kg for abdominal and iliac angiography (26)(27)(28), whereas Prince (29) showed that there is no improvement in image quality with doses higher than 0.2 mmol/kg. Thus, the dose depends on what blood vessels are to be visualized and on the individual preference of the radiologist in terms of what he or she considers to be adequate.…”

Gadobenate dimeglumine‐enhanced MR angiography: Diagnostic performance of four doses for detection and grading of carotid, renal, and aorto‐iliac stenoses compared to digital subtraction angiography

“…Thus, whereas there was a clear tendency for greater diagnostic accuracy with 0.1 mmol/kg gadobenate dimeglumine in each territory, statistical confirmation was possible only for the carotid and pelvic vasculature; the fact that DSA was performed in only 16 patients undergoing renal CE‐MRA precluded demonstration of a statistically significant benefit for the 0.1 mmol/kg dose in this territory. However, whereas this precludes meaningful interstudy comparisons of diagnostic accuracy for each vascular territory independently, the overall accuracy values with 0.1 mmol/kg gadobenate dimeglumine bear good comparison with values reported elsewhere for other agents at higher dose (26, 33–35, 37, 39, 42, 43, 45–47, 49). That DSA was performed for only 84 (21.4%) of 392 patients recruited across the original Phase II trials (17–19) despite only limited initial experience with gadobenate dimeglumine in CE‐MRA applications reflects not only the diagnostic accuracy achieved but also a high level of confidence on the part of investigators.…”

“…Whereas 20–25 mL (typically corresponding to ≈0.1–0.15 mmol/kg bodyweight) of these agents are commonly employed for CE‐MRA of the carotid arteries (34–37), the use of higher doses (25–30 mL; ≈0.2 mmol/kg bodyweight) has also been reported (38, 39). Similarly, doses of 0.2–0.3 mmol/kg bodyweight of conventional Gd‐based MR contrast agents are typically employed for CE‐MRA of the renal arteries (26, 40–46) and aorto‐iliac and peripheral regions (26, 47–49). Reported sensitivity and specificity values for the detection of clinically significant steno‐occlusive disease at these doses in these vascular territories frequently fall in the range between 90% and 100% (26, 33–35, 37, 39, 42, 43, 45–47, 49), indicating that CE‐MRA is an extremely accurate imaging modality when compared with traditional reference standard techniques such as conventional DSA.…”