Thymic hyperplasia and thymus gland tumors: Differentiation with chemical shift MR imaging
Thymic hyperplasia and thymus gland tumors: Differentiation with chemical shift MR imaging
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DOI：
10.1148/radiol.2433060797
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发表时间：
2007-06-01
期刊：
影响因子：
19.7
通讯作者：
Aburano, Tamio
中科院分区：
文献类型：
--
作者：
Inaoka, Tsutomu;Takahashi, Koji;Aburano, Tamio
目的：为了前瞻性地评估化学位移磁共振（MR）成像鉴别胸腺增生从肿瘤的thymus glands.Materials和Methods：机构审查委员会批准了这项研究，知情同意书获得和患者的保密性受到保护。作者评估了41例患者（17例男性，24例女性;年龄范围，16-78岁），其中胸部计算机断层扫描发现胸腺病变。患者被分配到增生组（n = 23）（18例与Graves病相关的胸腺增生患者和5例反跳性胸腺增生患者）和肿瘤组（n = 18）（7例胸腺瘤患者，4例浸润性胸腺瘤患者，5例胸腺癌患者和2例恶性淋巴瘤患者）。所有患者均获得T2加权快速自旋回波和T1加权同相和反相MR图像，并进行视觉评估。通过比较胸腺与椎旁肌的信号强度，计算化学位移比（CSR）用于定量分析。使用Welch t和Newman-Keuls检验分析患者组和亚组的平均CSR。P < .05，差异有统计学意义。结果：增生组23例患者的胸腺信号均匀，肿瘤组18例患者中有12例胸腺信号均匀。增生组的平均CSR（+/-标准差）为0.614 +/- 0.130，肿瘤组为1.026 +/- 0.039。胸腺增生和Graves病、反跳性胸腺增生、胸腺瘤、侵袭性胸腺瘤、胸腺癌和恶性淋巴瘤患者的平均CSR分别为0.594 +/- 0.120、0.688 +/- 0.154、1.033 +/- 0.043、1.036 +/- 0.040、1.020 +/- 0.044、和0.997 +/-0.010。增生组与肿瘤组之间的CSR差异有显著性（P < .001）。增生亚组的平均CSR低于肿瘤亚组（P <0.001）。所有增生组患者在化学位移MR成像时胸腺信号强度均明显降低，肿瘤组患者胸腺信号强度无明显降低。结论：化学位移MR成像可用于鉴别胸腺增生和胸腺肿瘤。
Purpose: To prospectively evaluate chemical shift magnetic resonance (MR) imaging for differentiating thymic hyperplasia from tumors of the thymus gland.Materials and Methods: The institutional review board approved this study; informed consent was obtained and patient confidentiality was protected. The authors assessed 41 patients (17 male, 24 female; age range, 16-78 years) in whom thymic lesions were seen at chest computed tomography. Patients were assigned to a hyperplasia group (n = 23) (18 patients with hyperplastic thymus associated with Graves disease and five with rebound thymic hyperplasia) and a tumor group (n = 18) (seven patients with thymomas, four with invasive thymomas, five with thymic cancers, and two with malignant lymphomas). T2-weighted fast spin-echo and T1-weighted in-phase and opposed-phase MR images were obtained in all patients and visually assessed. A chemical shift ratio (CSR), determined by comparing the signal intensity of the thymus gland with that of the paraspinal muscle, was calculated for quantitative analysis. Mean CSRs for the patient groups and subgroups were analyzed by using Welch t and Newman-Keuls tests. P < .05 indicated a significant difference.Results: The thymus gland had homogeneous signal intensity in all 23 patients in the hyperplasia group and in 12 of the 18 patients in the tumor group. The mean CSR (+/- standard deviation) was 0.614 +/- 0.130 in the hyperplasia group and 1.026 +/- 0.039 in the tumor group. Mean CSRs in the patients with a hyperplastic thymus and Graves disease, rebound thymic hyperplasia, thymoma, invasive thymoma, thymic cancer, and malignant lymphoma were 0.594 +/- 0.120, 0.688 +/- 0.154, 1.033 +/- 0.043, 1.036 +/- 0.040, 1.020 +/- 0.044, and 0.997 +/- 0.010, respectively. The difference in CSR between the hyperplasia and tumor groups was significant (P < .001). Mean CSRs in the hyperplasia subgroups were lower than those in the tumor subgroups (P < .001). All hyperplasia group patients had an apparent decrease in thymus gland signal intensity at chemical shift MR imaging; no tumor group patients had a decrease in thymus gland signal intensity.Conclusion: Chemical shift MR imaging can be used to differentiate thymic hyperplasia from thymic tumors.