MRI联合4D CEMRA诊断四肢远端长骨转移瘤

摘要

Objective:To explore the features of MR imaging combined with four-dimensional dynamic contrast-en-hanced MR angiography (4D CEMRA)in distal long bones metastasis.Methods:The routine MR scan and 4D CEMRA were carried out in 6 patients with pathologically confirmed long bones metastasis.Each cases was evaluated in the type of bone destruction,peripheral edema and the lesion signal characteristics.The signal intensity of each long bone metastases in early arterial,late arterial and venous phases of 4D CEMRA was compared,and the signal ratio of tumors signals and arter-ies was calculated.Results①Types of bone destruction:1.Cortical type (2 cases,both located in the diarhysis),2.Medullary type (4 cases;3 cases located in the metaphysis).②Extent of perifocal edema:large area of perifocal edema in 5 cases (5/6 ),mild edema in 1 case (1/6 ).③MR signal in lesion:inhomogeneous signal on MRI plain scan,and intensive enhancement of solid part in six cases.④Manifestations of 4D CEMRA:6 cases showed rapid enhancement in arterial phase,and the tumor'size significantly increased,and 4 cases showed"Suspended fruit"change,and 1 case showed"Holding ball"sign;in the equilibrium phase,the enhancement was less intensive than in venous phase.6 cases of long bone metastases show the tumor feeding artery,the display rate was 100%.Less than 3 feeding arteries were showed in 2 cases (33.3%);more than 3 arteries were showed in 4 cases (6 6 .7%).the tumor feeding artery showed three forms:reticular (Ⅰ),stubby shape (Ⅱ), long strips (Ⅲ).Conclusion:The MR imaging features of distal long bone metastasis exhibits diversity,and combination with malignant neoplastic blood vessels and tumor enhancement characteristics of 4D CEMRA can help to improve the diag-nostic accuracy.%目的：探讨 MRI联合4D CEMRA诊断四肢远端长骨转移瘤的意义。方法：分析经手术病理证实的6例四肢远端长骨转移瘤患者的 MRI、4D CEMRA资料，评估每例长骨转移瘤病变部位、骨质破坏类型、病变周围水肿、病变信号特点；测量4D CEMRA长骨转移瘤各期相信号强度，计算各期相瘤体信号与动脉信号的比值，比较不同期相瘤体的信号差异。结果：①骨质破坏部位类型：皮质型2例，均位于骨干。髓腔型4例，3例位于骨端，1例位于骨干。②病变水肿程度：6例中病变周围大片明显水肿5例，小片状轻度水肿1例。③病变信号：6例病例 MRI 平扫均表现信号不均匀，增强扫描6例病例肿瘤实质部分明显强化，T1 WI呈更低信号影未见强化。④4D CEMRA表现：动脉期6例瘤体迅速显影、瘤体信号明显增强，瘤体显现范围明显增大，4例呈“挂果征”改变，1例呈“抱球征”改变；至平衡期，瘤体显影范围固定，显影较静脉期稍减弱。6例长骨转移瘤显示瘤体供血动脉。瘤体供血动脉≤3支有2例；＞3支有4例。4D CEMRA 上瘤体供血动脉呈网状（Ⅰ）、粗短状（Ⅱ）、长条状（Ⅲ）3种表现。结论：长骨转移瘤 MRI表现多样性，结合4D CEMRA的恶性新生肿瘤血管和瘤体染色特点有助于提高诊断准确率。