MR全身弥散成像对恶性肿瘤全身转移及寻找原发灶方面的初步探索

Application of MR WB-DWI in finding unknown primary or metastatic tumors

目的评价MR全身弥散成像(WB-DWI)对恶性肿瘤全身转移及寻找原发灶的诊断价值以及评估其对恶性肿瘤骨转移的诊断价值。方法对17例已知转移灶寻找原发灶病例以及10例已知原发灶寻找转移灶病例行全身WB-DWI检查。11例患者同时行同位素骨扫描(SPECT)检查。对WB-DWI图像与常规MR图像和SPECT图像进行帧对帧对比分析,原发灶与转移灶ADC值进行定量分析,应用统计学进行数据处理。结果 17例已知转移瘤寻找原发灶病例,14例WB-DWI确定原发灶,经病理或其他影像学证实为原发灶13例,假阳性1例,余3例阴性病灶,经病理或其他影像资料证实未见原发灶2例,1例心影后方1.5 cm肺癌WB-DWI漏诊,经CT及穿刺细胞学证实为肺腺癌,经配对t检验统计学分析,原发灶与转移灶ADC值差异无统计学意义(P>0.05)。11例同时行骨扫描及WB-DWI患者,二者均阳性8例,骨扫描假阳性1例,WB-DWI假阳性1例,另1例二者均为假阴性的病灶位于左肋弓前方疼痛结节,病理证实为乳腺癌转移结节,WB-DWI与SPECT对恶性肿瘤骨转移检出率差异无统计学意义。结论 WB-DWI对全身转移灶及寻找原发灶方面均有较高的检出率,且WB-DWI对原发灶及检出其他部位转移灶方面明显优于SPECT,WB-DWI有望成为筛查恶性肿瘤患者全身转移及寻找原发灶的一种新型手段。

Objective To evaluate the application of MR whole-body diffusion weighted imaging（WB-DWI） in finding unknown primary or metastatic tumors.Methods WB-DWI scan was performed in 17 cancer patients with known metastatic tumor and 10 patients with known primary tumors to detect the primary tumors or metastatic tumors,respectively.Among them 11 cases received SPECT examination at the same time,and the imagines were compared with WB-DWI findings.The values of ADC of metastasis and primary tumors were detected and the data analyzed using SPSS software.Results Among 17 cases with metastatic tumors their primary tumors were found in 14,in 13 of whom the tumors were confirmed by pathology or other imaging techniques and 1 case was false-positive.In the rest 3 cases,2 were negative in pathology or other imaging examinations,in the third patient CT and puncture-cytology confirmed a 1.5 cm pulmonary adenocarcinoma behind the heart,which was missed by WB-DWI.There was no significant difference in ADC value between primary and metastatic tumors（P0.05）.In 11 patients who received both SPECT scan and WB-DWI examinations,there were 8 cases with dual-positive results,and 2 cases with either false-positive in SPECT or false-positive in DWI;and 1 case with false-negative of both examination was finally confirmed as metastasis from mastocarcinoma.Conclusion With high sensibility WB-DWI can be used in finding primary or metastatic malignant tumors.