全身DWI的正常表现及在转移瘤筛查中的临床应用

Whole body magnetic resonance diffusion weighted imaging:the normal appearances and its application in detection of metastasis

目的:探讨磁共振全身扩散加权成像(全身DWI)的正常表现及在转移瘤筛查中的应用价值。方法:20例健康志愿者及25例疑似或确诊恶性肿瘤患者行磁共振全身扩散加权成像,其中11例肿瘤患者同时行PET/CT检查。全身DWI应用STIR抑制背景信号,从头顶至股骨上分段无间隔扫描,共覆盖1080～1440mm,b值取0及600s/mm2。结果:在健康志愿者的全身DWI像上,脑实质、涎腺、椎间盘、脊髓、脾脏、肾脏和前列腺、睾丸、子宫、卵巢等脏器呈高信号,其余脏器及骨骼呈等信号。原发恶性肿瘤及转移灶在全身DWI呈明显高信号,对比度高于常规MRI序列。25例患者全身DWI共检出70处高信号病灶,包括原发恶性肿瘤及转移灶68处,良性病灶2处,显示率为98.6%。11例PET/CT检查共有20处阳性显像,原发恶性肿瘤及转移灶16处,良性病灶4处,显示率100%。结论:磁共振全身扩散加权成像一次检查可完成从头顶至股骨上段的大范围成像,对恶性肿瘤原发灶及转移灶有较高的显示率,可以作为恶性肿瘤患者原发及转移灶筛查的有力工具之一。

Objective： To investigate the normal appearances of MR whole body diffusion weighted imaging （WBDWI） and the value of WB-DWI in detection of metastasis. Methods： Twenty healthy volunteers and 25 patients suspected for different kinds of malignancy or confirmed by pathology underwent WB-DWI. Eleven of them underwent PET/CT sim- ultaneously. Whole body background signal was suppressed with STIR. The scanning range was 1080~1440mm from head to superior segments of the femurs with b values of 0 and 600s/mm2. The scanning was performed segment by segment without interval. Results： Some organs such as brain, salivary glands, intervertebral discs, spinal marrow, spleen, kidneys, prostate, testes and uterus as well as ovaries showed hyperintensity on healthy volunteers WB-DWl,while the other organs including skeleton showed isointensity. Primary malignancy and whole body metastasis showed significant hyperintensities and had a higher contrast than conventional MRI sequences. WBDWI had detected 70 hyperintense lesions including 68 ma- lignant and 2 benign ones. The detection rate was 98.6%. Among the 11 cases, PET/CT had detected 16 malignancies inclu ding primary malignancies and metastases, and 4 benign lesions. The detection rate was 100%. Conclusion： Because WBMR DWI can image the whole body during one examination and have a high detection rate for primary malignancies and metasta ses,it will be a potential tool to screen the metastases of whole body in patients with malignancy.