Barceló J, Vilanova J C, Riera E, Balliu E, Peláez I, Martí J, Villalón M, Ruscalleda N
Unidad de Resonancia Magnética, Clínica Girona, Gerona, España.
Radiologia. 2007 Nov-Dec;49(6):407-15. doi: 10.1016/s0033-8338(07)73811-0.
To present our preliminary experience in whole-body MRI with an added diffusion-weighted sequence in screening for osseous metastases.
24 patients with malignant neoplasms underwent bone scintigraphy and whole-body MRI with the addition of a diffusion-weighted sequence. Whole-body MRI was performed on a 1.5 T unit using a three-station protocol; coronal T1-weighted FSE and STIR sequences and sagittal T1-weighted FSE of the spine were acquired. A diffusion-weighted sequence (b: 600 s/mm2) was added in the axial plane at five different stations and iconographic presentation in coronal-plane reconstructions with contrast inversion was used to obtain an image similar to that provided by PET (virtual PET). The findings at bone scintigraphy (BS) and MRI were compared for the presence of osseous metastases, evaluating the results for each patient both globally and for different osseous regions. Metastatic lesions were confirmed by biopsy or by six to eight months' follow-up.
Globally, whole-body MRI with diffusion-weighted sequences was superior to bone scintigraphy, with a sensitivity of 100% (BS 71%), specificity 90% (BS 80%), and reliability 96% (BS 75%). In the evaluation by osseous region, the results of MRI were also better than those of bone scintigraphy: sensitivity 96% (BS 52%). In the diffusion-weighted sequence, lytic metastases were hyperintense in all cases, with an apparent diffusion coefficient (ADC) value higher than normal bone but lower than lesions with acute edema of benign etiology. Whole-body MRI also revealed unknown extraosseous findings related to the tumors and extraosseous metastases in 42% of the patients.
Whole-body MRI with an added diffusion-weighted sequence is an efficacious method of detecting osseous metastases and is more reliable than bone scintigraphy. Moreover, whole-body MRI provides information about extraosseous lesions. Lytic metastases are hyperintense in diffusion-weighted sequences and have a lower ADC than benign edema.
介绍我们在全身MRI检查中增加弥散加权序列用于筛查骨转移瘤的初步经验。
24例恶性肿瘤患者接受了骨闪烁显像及增加弥散加权序列的全身MRI检查。全身MRI检查在1.5T设备上采用三部位检查方案进行；获取脊柱的冠状位T1加权快速自旋回波（FSE）序列、短TI反转恢复（STIR）序列以及矢状位T1加权FSE序列图像。在五个不同部位的轴位增加弥散加权序列（b值：600s/mm²），并使用对比反转的冠状位重建图像呈现方式来获得类似于正电子发射断层显像（PET）提供的图像（虚拟PET）。比较骨闪烁显像（BS）和MRI检查结果中骨转移瘤的情况，对每位患者的整体结果以及不同骨区域的结果进行评估。转移瘤病变通过活检或6至8个月的随访得以确诊。
总体而言，增加弥散加权序列的全身MRI检查优于骨闪烁显像，其灵敏度为100%（骨闪烁显像为71%），特异性为90%（骨闪烁显像为80%），可靠性为96%（骨闪烁显像为75%）。在按骨区域评估时，MRI检查结果也优于骨闪烁显像：灵敏度为96%（骨闪烁显像为52%）。在弥散加权序列中，溶骨性转移瘤在所有病例中均表现为高信号，表观扩散系数（ADC）值高于正常骨但低于良性病因急性水肿的病变。全身MRI检查还在42%的患者中发现了与肿瘤相关的未知骨外表现及骨外转移瘤。
增加弥散加权序列的全身MRI检查是检测骨转移瘤的有效方法，比骨闪烁显像更可靠。此外，全身MRI检查可提供有关骨外病变的信息。溶骨性转移瘤在弥散加权序列中表现为高信号，且ADC值低于良性水肿。
