Department of Diagnostic Radiology, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Rd, Rm 406, Block K, Hong Kong.
AJR Am J Roentgenol. 2011 Sep;197(3):W384-91. doi: 10.2214/AJR.10.5692.
The objective of our study was to evaluate the diagnostic performance of conventional whole-body MRI without and with diffusion-weighted imaging (DWI) in the detection of known (18)F-FDG-avid lymphomas. The conventional whole-body MRI protocol consisted of a T2-weighted sequence and a T2-weighted spectral attenuated inversion recovery (SPAIR) sequence with frequency-selective fat suppression. The second protocol used the same sequences as the first protocol but also included DWI.
Seventeen patients with pathologically confirmed, newly diagnosed, untreated lymphoma were recruited. T2-weighted and T2-weighted SPAIR images were evaluated first, separate from the DW images, and then were evaluated with the DW images. We used (18)F-FDG PET/CT as the standard of reference. True-positive, false-positive, and false-negative values were evaluated on a per-lesion basis. Tumor staging based on T2-weighted and T2-weighted SPAIR imaging without DWI and then with DWI was compared using the Ann Arbor staging system.
True-positive lesions were increased from 89% to 97%, false-positive lesions were increased from 3% to 6%, and false-negative lesions were decreased from 11% to 3% by the addition of DWI. Diagnostic sensitivity was significantly increased (p = 0.002) by adding DWI. Lesions detected on DWI but not on T2-weighted and T2-weighted SPAIR imaging were located in renal (n = 1), paraaortic (n = 6), and pelvic (n = 3) lymph nodes. On DWI, 47% of the lesions (n = 55) were more conspicuous than on T2-weighted and T2-weighted SPAIR imaging; most of these lesions (58%, n = 32) were from lymph nodes in the pelvic or abdominal regions and bone marrow. No difference was found between T2-weighted and T2-weighted SPAIR imaging without DWI and T2-weighted and T2-weighted SPAIR imaging with DWI in lymphoma staging, being consistent with PET/CT in 88% of the patients (n = 15).
The addition of DWI to conventional whole-body MRI sequences enhanced lesion conspicuity and improved diagnostic accuracy for lymphomas. With technical optimization, whole-body MRI with DWI, as a nonionizing imaging modality, may potentially be useful as an alternative method to PET/CT in the management of malignant lymphoma.
本研究旨在评估常规全身 MRI 联合或不联合弥散加权成像（DWI）在检测已知（18）F-FDG 摄取淋巴瘤中的诊断性能。常规全身 MRI 方案包括 T2 加权序列和 T2 加权频谱衰减反转恢复（SPAIR）序列，带有频率选择脂肪抑制。第二方案使用与第一方案相同的序列，但也包括 DWI。
共纳入 17 例经病理证实的、新诊断的、未经治疗的淋巴瘤患者。首先独立于 DW 图像评估 T2 加权和 T2 加权 SPAIR 图像，然后与 DW 图像一起评估。我们将（18）F-FDG PET/CT 作为参考标准。基于每处病变评估真阳性、假阳性和假阴性值。比较了不使用 DWI 和使用 DWI 后基于 T2 加权和 T2 加权 SPAIR 成像的肿瘤分期，使用安阿伯分期系统。
DWI 的加入使真阳性病变从 89%增加到 97%，假阳性病变从 3%增加到 6%，假阴性病变从 11%减少到 3%。添加 DWI 后诊断敏感性显著提高（p = 0.002）。在 DWI 上检测到而在 T2 加权和 T2 加权 SPAIR 成像上未检测到的病变位于肾（n = 1）、主动脉旁（n = 6）和盆腔（n = 3）淋巴结。在 DWI 上，47%（n = 55）的病变比 T2 加权和 T2 加权 SPAIR 成像更明显；其中大多数病变（58%，n = 32）来自盆腔或腹部淋巴结和骨髓。不使用 DWI 的 T2 加权和 T2 加权 SPAIR 成像与使用 DWI 的 T2 加权和 T2 加权 SPAIR 成像在淋巴瘤分期方面没有差异，与 PET/CT 一致，在 88%的患者（n = 15）中。
常规全身 MRI 序列中添加 DWI 可提高病变的显影度，并提高淋巴瘤的诊断准确性。通过技术优化，DWI 全身 MRI 作为一种非电离成像方式，可能有潜力替代 PET/CT 用于恶性淋巴瘤的治疗。
