| 저자(한글) |
Zhu, C.,Haraldsson, H.,Faraji, F.,Owens, C.,Gasper, W.,Ahn, S.,Liu, J.,Laub, G.,Hope, M.D.,Saloner, D. |
| 초록 |
Introduction: The aortic wall and intraluminal thrombus (ILT) have been increasingly studied as potential markers of progressive disease with abdominal aortic aneurysms (AAAs). Our goal was to develop a high resolution, 3D black blood MR technique for AAA wall and ILT imaging within a clinically acceptable scan time. Methods: Twenty two patients with AAAs (maximal diameter 4.3+/-1.0cm), along with five healthy volunteers, were imaged at 3T with a 3D T 1 -weighted fast-spin-echo sequence using variable flip angle trains (SPACE) with a preparation pulse (DANTE) for suppressing blood signal. Volunteers and ten patients were also scanned with SPACE alone for comparison purposes. The signal to noise ratio (SNR) and the aortic wall/ILT to lumen contrast to noise ratio (CNR) were measured. Qualitative image scores (1-4 scale) assessing the inner lumen and outer wall boundaries of AAA were performed by two blinded reviewers. In patients with ILT, the ratio of ILT signal intensity (ILT SI ) over psoas muscle SI (Muscle SI ) was calculated, and the signal heterogeneity of ILT was quantified as standard deviation (SD) over the mean. Results: All subjects were imaged successfully with an average scan time of 7.8+/-0.7minutes. The DANTE preparation pulse for blood suppression substantially reduced flow artifacts in SPACE with lower lumen SNR (8.8 vs. 21.4, p 0.05). ILT was present in ten patients, with relatively high signal and a wide SD (average ILT SI /Muscle SI 1.42+/-0.48 (range 0.75-2.11)) and with SD/mean of 27.7%+/-6.6% (range 19.6%-39.4%). Conclusion: High resolution, 3D black blood MRI of AAAs can be achieved in a clinical accepted scan time with reduction of flow artifacts using the DANTE preparation pulse. Signal characteristics of ILT can be quantified and may be used for improved patient-specific risk stratification. |
