Department of Radiology, Sheba Medical Center, Israel.
Sackler School of Medicine, Tel Aviv University, Israel.
J Magn Reson Imaging. 2019 Feb;49(2):508-517. doi: 10.1002/jmri.26228. Epub 2018 Aug 31.
Pregnancy-associated breast cancer (PABC) is often a delayed diagnosis and contrast-enhanced MRI is contraindicated because gadolinium agents are known to cross the placenta.
To investigate the feasibility and clinical utility of noncontrast breast MRI using diffusion tensor imaging (DTI) in the diagnostic workup of PABC.
Prospective.
Between November 2016 and January 2018, 25 pregnant participants (median gestational age: 17 weeks) were recruited from eight referral breast-care centers nationwide. Imaging indications included: newly-diagnosed PABC (n = 10, with 11 lesions), palpable mass/mastitis (n = 4), high-risk screening (n = 10), and monitoring neoadjuvant-chemotherapy response (n = 1).
FIELD STRENGTH/SEQUENCE: 1.5T, T -weighted, and DTI sequences, prone position, with a scan duration of ∼12 minutes.
DTI parametric maps were generated and analyzed at pixel resolution, with reference to ultrasound (US) and pathology.
Two-tailed Student's t-test was applied for evaluating differences between DTI parameters of PABC vs. healthy fibroglandular tissue. Pearson's correlation test was applied to measure the agreements between λ1-based longest tumor diameter, US, and pathology.
All scans were technically completed and reached diagnostic quality, except one with notable motion artifacts due to positional discomfort, which was excluded. Nine out of 11 known PABC lesions and one newly-diagnosed lesion were visible on λ1, λ2, λ3, mean diffusivity (MD), and λ1-λ3 maps, with substantial parametric contrast compared with the apparently normal contralateral fibroglandular tissue (P < 0.001 for all). Two lesions of 0.7 cm were not depicted by the diffusivity maps. Tumor diameter measured on a thresholded λ1 map correlated well with US (r = 0.97) and pathology (r = 0.95). Malignancy was excluded by DTI parametric maps in scans of symptomatic and high-risk patients, in agreement with US follow-up, except for one false-positive case.
Noncontrast breast MRI is feasible and well-tolerated during pregnancy. Further studies with a larger and homogeneous cohort are required to validate DTI's additive diagnostic value, albeit this study suggests a potential adjunct role for this noninvasive approach in breast evaluation during pregnancy.
2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:508-517.
妊娠相关性乳腺癌（PABC）常延迟诊断，因钆造影剂已知会穿过胎盘，故禁忌使用对比增强 MRI。
研究扩散张量成像（DTI）在诊断 PABC 中的可行性和临床应用价值。
前瞻性。
2016 年 11 月至 2018 年 1 月，从全国 8 个乳腺保健中心招募了 25 名孕妇（中位妊娠周数：17 周）。影像学适应证包括：新诊断的 PABC（n=10，11 个病灶）、可触及肿块/乳腺炎（n=4）、高危筛查（n=10）和监测新辅助化疗反应（n=1）。
磁场强度/序列：1.5T，T1 加权和 DTI 序列，俯卧位，扫描时间约 12 分钟。
在像素分辨率下生成和分析 DTI 参数图，并参考超声（US）和病理结果。
采用双尾 Student's t 检验比较 PABC 与健康纤维腺体组织的 DTI 参数差异。采用 Pearson 相关检验测量基于 λ1 的最长肿瘤直径、US 和病理之间的一致性。
除因体位不适导致明显运动伪影而放弃的 1 例外，所有扫描均完成并达到诊断质量。11 个已知 PABC 病灶中的 9 个和新诊断的 1 个病灶在 λ1、λ2、λ3、平均扩散系数（MD）和 λ1-λ3 图上可见，与对侧明显正常纤维腺体组织的参数对比度有显著差异（所有 P<0.001）。两个直径 0.7cm 的病灶未在弥散图上显示。基于阈值的 λ1 图上测量的肿瘤直径与 US（r=0.97）和病理（r=0.95）高度相关。除 1 例假阳性外，DTI 参数图排除了症状性和高危患者扫描中的恶性肿瘤，与 US 随访结果一致。
非对比性乳腺 MRI 在妊娠期间是可行的，且患者耐受性良好。需要进一步的研究来验证 DTI 的附加诊断价值，尽管本研究提示这种非侵入性方法在妊娠期间乳腺评估中有潜在的辅助作用。
2 技术功效：1 级。磁共振成像杂志 2019；49：508-517。
