Lam P D, Kuribayashi A, Imaizumi A, Sakamoto J, Sumi Y, Yoshino N, Kurabayashi T
1 Department of Oral and Maxillofacial Radiology, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Br J Radiol. 2015 May;88(1049):20140685. doi: 10.1259/bjr.20140685. Epub 2015 Mar 20.
To determine the optimal diagnostic criterion of dynamic contrast-enhanced MRI (DCE-MRI) for predicting salivary gland malignancy using a dynamic sequence with high temporal resolution, as well as the accuracy of this technique.
The DCE-MRI findings of 98 salivary gland tumours (74 benign and 24 malignant) were reviewed. MR images were sequentially obtained at 5-s intervals for 370 s. Two parameters, peak time and washout ratio (WR) were determined from the time-signal intensity curve. The optimal thresholds of these parameters for differentiating benign and malignant tumours were determined, along with the diagnostic accuracy of the criterion using these thresholds.
A peak time of 150 s and a WR of 30% were identified as optimal thresholds. As the criterion for malignancy, the combination of peak time <150 s and WR <30% provided a sensitivity of 79% (19/24), specificity of 95% (70/74) and an overall accuracy of 91% (89/98). Three of the five false-negative cases were malignant lymphomas of the parotid gland.
Peak time <150 s with WR <30% comprised the optimal diagnostic criterion in predicting salivary gland malignancy, providing a sensitivity of 79% and specificity of 95%. The use of high temporal resolution might improve the accuracy of DCE-MRI.
Although several studies have reported the usefulness of DCE-MRI in the differential diagnosis of salivary gland tumours, the specific diagnostic criteria employed have differed widely. We determined the optimal criterion and its accuracy using a dynamic sequence with high temporal resolution.
使用具有高时间分辨率的动态序列确定动态对比增强磁共振成像（DCE-MRI）预测涎腺恶性肿瘤的最佳诊断标准及其技术准确性。
回顾了98例涎腺肿瘤（74例良性和24例恶性）的DCE-MRI表现。以5秒的间隔连续采集MR图像，共采集370秒。从时间-信号强度曲线中确定两个参数，即达峰时间和廓清率（WR）。确定这些参数区分良性和恶性肿瘤的最佳阈值，以及使用这些阈值的标准的诊断准确性。
达峰时间150秒和WR 30%被确定为最佳阈值。作为恶性肿瘤的标准，达峰时间<150秒且WR<30%的组合敏感性为79%（19/24），特异性为95%（70/74），总体准确率为91%（89/98）。5例假阴性病例中有3例是腮腺恶性淋巴瘤。
达峰时间<150秒且WR<30%构成预测涎腺恶性肿瘤的最佳诊断标准，敏感性为79%，特异性为95%。使用高时间分辨率可能会提高DCE-MRI的准确性。
尽管多项研究报道了DCE-MRI在涎腺肿瘤鉴别诊断中的有用性，但所采用的具体诊断标准差异很大。我们使用具有高时间分辨率的动态序列确定了最佳标准及其准确性。
