Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, New Territories, Hong Kong SAR, China.
Department of Chemical Pathology, State Key Laboratory Translational Oncology, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China.
Eur Radiol. 2019 Oct;29(10):5627-5634. doi: 10.1007/s00330-019-06133-8. Epub 2019 Mar 22.
MRI can detect early-stage nasopharyngeal carcinoma (NPC), but the detection is more challenging in early-stage NPCs because they must be distinguished from benign hyperplasia in the nasopharynx. This study aimed to determine whether intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) MRI could distinguish between these two entities.
Thirty-four subjects with early-stage NPC and 30 subjects with benign hyperplasia prospectively underwent IVIM DWI. The mean pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) values were calculated for all subjects and compared between the 2 groups using Student's t test. Receiver operating characteristics with the area under the curve (AUC) was used to identify the optimal threshold for all significant parameters, and the corresponding diagnostic performance was calculated. A p value of < 0.05 was considered statistically significant.
Compared with benign hyperplasia, early-stage NPC exhibited a significantly lower D mean (0.64 ± 0.06 vs 0.87 ± 0.11 × 10 mm/s), ADC mean (0.77 ± 0.08 vs 1.00 ± 0.13 × 10 mm/s), ADC (0.63 ± 0.05 vs 0.86 ± 0.10 × 10 mm/s) and a higher D* mean (32.66 ± 4.79 vs 21.96 ± 5.21 × 10 mm/s) (all p < 0.001). No significant difference in the f mean was observed between the two groups (p = 0.216). The D and ADC mean had the highest AUC of 0.985 and 0.988, respectively, and the D mean of < 0.75 × 10 mm/s yielded the highest sensitivity, specificity and accuracy (100%, 93.3% and 96.9%, respectively) in distinguishing early-stage NPC from benign hyperplasia.
DWI has potential to distinguish early-stage NPC from benign hyperplasia and D and ADC mean were the most promising parameters.
• Diffusion-weighted imaging has potential to distinguish early-stage nasopharyngeal carcinoma from benign hyperplasia in the nasopharynx. • The pure diffusion coefficient, pseudo-diffusion coefficient from intravoxel incoherent motion model and apparent diffusion coefficient from conventional diffusion-weighted imaging were significant parameters for distinguishing these two entities in the nasopharynx. • The pure diffusion coefficient, followed by apparent diffusion coefficient, may be the most promising parameters to be used in screening studies to help detect early-stage nasopharyngeal carcinoma.
MRI 可检测早期鼻咽癌（NPC），但在早期 NPC 中检测更为具有挑战性，因为必须将其与鼻咽部良性增生相区分。本研究旨在确定体素内不相干运动扩散加权成像（IVIM DWI）MRI 是否可用于区分这两种病变。
前瞻性纳入 34 例早期 NPC 患者和 30 例良性增生患者，所有患者均进行 IVIM DWI 检查。采用双指数模型计算平均纯扩散系数（D）、假性扩散系数（D*）、灌注分数（f）和表观扩散系数（ADC）值，采用 Student's t 检验比较两组间各参数值的差异。采用受试者工作特征曲线（ROC）确定各有统计学意义参数的最佳阈值，并计算其相应的诊断效能。以 P 值<0.05 为差异有统计学意义。
与良性增生相比，早期 NPC 的 D 值（0.64±0.06 比 0.87±0.11×10mm/s）、ADC 值（0.77±0.08 比 1.00±0.13×10mm/s）、ADC（0.63±0.05 比 0.86±0.10×10mm/s）更低，D*值（32.66±4.79 比 21.96±5.21×10mm/s）更高（均 P<0.001）。两组的 f 值差异无统计学意义（P=0.216）。D 值和 ADC 值的 AUC 最高，分别为 0.985 和 0.988，D 值<0.75×10mm/s 时鉴别早期 NPC 和良性增生的敏感度、特异度和准确度最高（分别为 100%、93.3%和 96.9%）。
DWI 有望用于区分早期 NPC 和良性增生，D 值和 ADC 值是最有前景的参数。
