Background/Objectives: Lung nodules present a common diagnostic challenge, particularly when benign and malignant lesions exhibit similar imaging characteristics. Standard evaluation relies on computed tomography (CT), positron emission tomography (PET), or biopsy, all of which have limitations. Quantitative magnetic resonance (MR) relaxometry using native longitudinal relaxation time (T1) and transverse relaxation time (T2) mapping offers a radiation-free alternative reflecting tissue-specific differences.Methods: This prospective, single-center study included 64 patients with 76 histologically or radiologically confirmed lung lesions (25 primary lung cancers, 28 metastases, 9 granulomas, and 14 pneumonic infiltrates). The patients underwent T1 and T2 mapping at 3T. Two independent readers quantified the mean values for each lesion. The pre-specified primary endpoints were (1) benign versus malignant and (2) primary lung cancer versus pulmonary metastases.Results: Significant differences in T1 and T2 values were observed across lesion types. Benign lesions exhibited high T2 values (mean 213.6 ms) and low T1 values (mean 836.6 ms), whereas malignant tumors exhibited lower T2 values (~77–78 ms) and higher T1 values (~1460–1504 ms,p< 0.001). Binary classification yielded 95.7% accuracy (sensitivity 93.8% for malignant, specificity 100% for benign) in an internal 70/30 hold-out validation (no external dataset), with consistent performance confirmed by patient-level and nested cross-validation (balanced accuracy ≈ 0.92–0.94). However, malignant subtypes could not be reliably distinguished (p> 0.05), and multiclass accuracy was 60.9%.Conclusions: Quantitative MR relaxometry allows accurate, radiation-free differentiation of benign and malignant lung lesions and may help reduce unnecessary invasive procedures.
**背景/目的：** 肺结节是常见的诊断难题，尤其当良性与恶性病变在影像学上表现相似时。标准评估依赖于计算机断层扫描（CT）、正电子发射断层扫描（PET）或活检，但这些方法均存在局限性。利用固有纵向弛豫时间（T1）和横向弛豫时间（T2）映射的定量磁共振（MR）弛豫测量法，提供了一种无辐射的替代方案，能够反映组织特异性差异。 **方法：** 这项前瞻性、单中心研究纳入了64名患者，共76个经组织学或影像学证实的肺部病灶（25个原发性肺癌，28个转移瘤，9个肉芽肿，14个肺炎性浸润）。患者在3T场强下接受了T1和T2映射扫描。两名独立的阅片者对每个病灶的平均值进行了量化。预设的主要终点为：（1）良性 vs. 恶性；（2）原发性肺癌 vs. 肺转移瘤。 **结果：** 不同病灶类型间的T1和T2值存在显著差异。良性病灶表现出较高的T2值（平均213.6 ms）和较低的T1值（平均836.6 ms），而恶性肿瘤则表现出较低的T2值（约77–78 ms）和较高的T1值（约1460–1504 ms，p < 0.001）。在内部70/30保留验证（无外部数据集）中，二元分类的准确率达到95.7%（恶性敏感性93.8%，良性特异性100%），其性能一致性通过患者层面和嵌套交叉验证得到确认（平衡准确度≈0.92–0.94）。然而，恶性亚型无法可靠区分（p > 0.05），多分类准确率为60.9%。 **结论：** 定量MR弛豫测量法能够准确、无辐射地区分良性和恶性肺部病灶，可能有助于减少不必要的侵入性操作。
Beyond Morphology: Quantitative MR Relaxometry in Pulmonary Lesion Classification
肿瘤(癌症)患者之家