Comparative study of MR diffusion weighted imaging for breast with different b values
10.3760/cma.j.issn.1005-1201.2009.04.006
- VernacularTitle:不同扩散梯度因子值的乳腺MR扩散加权成像对比研究
- Author:
Xin CHEN
;
Rui YAN
;
Huafeng KANG
;
Youmin GUO
;
Xian ZHAO
;
Changan HE
;
Yili ZHANG
- Publication Type:Journal Article
- Keywords:
Breast disease;
Diffusion magnetic resonance imaging
- From:
Chinese Journal of Radiology
2009;43(4):356-359
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the optimal b value in MR DWI for breast.Methods Forty patients with palpable masses of breasts underwent MR and DWI at b = 1000, 800 and 600 s/mm2 before surgery according prospective planning. Visual assessment, signal to noise ratio (SNR) of DWI and the ADC values of benign and malignant lesions were compared among three b values using one-way ANOVA test.The diagnostic value of ADC were analyzed by ROC curves.Results Of the 40 patients, there were 26 patients with malignant lesions and 14 patients with benign lesions verified by histopathology.36 patients with 42 lesions were examined by DWI, and detectabilities at three b values were alike.Most DWI at b = 1000, 800 and 600 s/mm2 were of high quality, and images of grade A were 75.0% (30/40), 77.5% (31/40) and 77.5% (31/40), respectively.Mean SNR at b = 1000, 800 and 600 s/mm2 were 63 ± 22,82 ± 27 and 96 ± 29 respectively.Compared with one another, there was statistically significant difference (P <0.01).Mean ADC of benign lesions at different b values were (1.44 ± 0.28) × 10-3, (1.50 ± 0.32) × 10-3 and (1.52±0.29) × 10-3 mm2/s respectively. Compared with one another, there was no statistically significant difference (P = 0.725).Mean ADC of malignant lesions were (1.00 ± 0.25) × 10-3, (0.98 ± 0.19) × 10-3 and (1.07 ± 0.22) × 10-3 mm2/s respectively.Compared with one another, there was also no statistically significant difference (P = 0.358).The area under the ROC curves at b = 1000,800 and 600 s/mm2 were 0.879,0.885 and 0.865 respectively.Threshold value to distinguish benign and malignant lesions were 1.295 × 10-3,1.435×10-3 and 1.335×10-3 mm2/s respectively.Sensitivity of diagnosing breast cancer were 80.0%, 92.0% and 84.0%, and specificity were all 90.0% . Positive predictive values were 95.2%, 95.8% and 95.5% at b = 1000, 800 and 600 s/mm2.Conclusion Combining SNR and the value of ADC in diagnosing benign and malignant breast lesions, the study indicated that b = 800 s/mm2 was the optimal b value in breast DWI.
