MR DSA在四肢肌骨系统疾病应用中的技术探讨

Technical Investigation of MR DSA for Musculoskeletal Diseases of Extremities

目的 探讨增强MR数字减影血管造影检查 (MRDSA)在四肢肌骨系统疾病应用中的技术问题。材料与方法 对 13例肌骨系统疾病患者行常规MRI扫描之后 ,行MRDSA检查。MRDSA采用三维稳态破坏性梯度回返采集 (three dimensionalspoiledgradientrecalledacquisitioninsteadystate,3D SPGR)序列进行扫描 ,扫描参数为 :TR 10 .3ms或 12 .5ms ,TE 1.9ms或 2 .8ms ;翻转角 3 0° ,层厚 1～3mm ,视野 2 8mm× 2 1mm～ 48mm× 3 6mm ;矩阵 2 5 6× 12 8,激励 1次 ,扫描时间 3 2秒。原始图像经过减影处理后再经最大信号强度投影 (MIP)重建。结果 13例中 ,上肢 2例 ,下肢 11例。软组织恶性肿瘤 2例 ,血管性疾病 6例 ,良性骨肿瘤 3例 ,恶性骨肿瘤 2例。混合型血管瘤 4例 ,MRDSA清楚显示供血动脉 3例 ;2例皮下小的海绵状血管瘤未显供血来源 ,但因其基本与动脉同期强化 ,对诊断很有帮助。 1例软组织内恶性纤维组织细胞瘤清楚显示动脉受压及多条肿瘤动脉供血。结论 MRDSA具有扫描时间短、成像质量高、信息量大等优点 ,在肢体疾病的诊断应用中将大有作为。

Objective To study the technique of MR DSA in the use of musculoskeletal diseases of extremities.Materials and Methods Following conventional MRI, dynamic 3D SPGR was performed in 13 cases with surgically and pathologically proved musculoskeletal disease in limbs, using RT 10.3 or 12.5ms, ET 1.9 or 2.8ms, flip angle 30°, slice 1～3mm, FOV 28mm×21mm～48mm×36mm, matrix 156×128, Nex 1, and scan time 32s. Having been processed by subtraction from mask image, the source images were reconstructed with MIP.Results Of 13 cases, 2 were located in upper extremities and 11 in lower extremities. The diseases included malignant soft tissue tumor (n=2), vascular lesion (n=7), malignant skeletal tumor (n=2) and benign skeletal tumor (n=3). MR DSA well displayed the feeding artery in 3 out of 4 cases with fixed aneurysm. Two cases with small subcutaneous cavernoma demonstrated enhancement though their feeding arteries were not revealed. It was still helpful to the diagnosis as their enhancement was consistent with arterial enhancement. One case of malignant fibrous histiocytoma showed several tumor feeding arteries and pressure signs of the arteries.Conclusion MR DSA has many advantages, such as short scan time, high quality imaging, and rich information. It, therefore, plays an important roll in the diagnosing of musculoskeletal diseases.