Breast Cancer: Diffusion Kurtosis MR Imaging-Diagnostic Accuracy and Correlation with Clinical-Pathologic Factors.
OBJECTIVE
To assess diagnostic accuracy with diffusion kurtosis imaging (DKI) in patients with breast lesions and to evaluate the potential association between DKI-derived parameters and breast cancer clinical-pathologic factors.


METHODS
Institutional review board approval and written informed consent were obtained. Data from 97 patients (mean age ± standard deviation, 45.7 years ± 13.1; range, 19-70 years) with 98 lesions (57 malignant and 41 benign) who were treated between January 2014 and April 2014 were retrospectively analyzed. DKI (with b values of 0-2800 sec/mm(2)) and conventional diffusion-weighted imaging data were acquired. Kurtosis and diffusion coefficients from DKI and apparent diffusion coefficients from diffusion-weighted imaging were measured by two radiologists. Student t test, Wilcoxon signed-rank test, Jonckheere-Terpstra test, receiver operating characteristic curves, and Spearman correlation were used for statistical analysis.


RESULTS
Kurtosis coefficients were significantly higher in the malignant lesions than in the benign lesions (1.05 ± 0.22 vs 0.65 ± 0.11, respectively; P < .0001). Diffusivity and apparent diffusion coefficients in the malignant lesions were significantly lower than those in the benign lesions (1.13 ± 0.27 vs 1.97 ± 0.33 and 1.02 ± 0.18 vs 1.48 ± 0.33, respectively; P < .0001). Significantly higher specificity for differentiation of malignant from benign lesions was shown with the use of kurtosis and diffusivity coefficients than with the use of apparent diffusion coefficients (83% [34 of 41] and 83% [34 of 41] vs 76% [31 of 41], respectively; P < .0001) with equal sensitivity (95% [54 of 57]). In patients with invasive breast cancer, kurtosis was positively correlated with tumor histologic grade (r = 0.75) and expression of the Ki-67 protein (r = 0.55). Diffusivity was negatively correlated with tumor histologic grades (r = -0.44) and Ki-67 expression (r = -0.46).


CONCLUSIONS
DKI showed higher specificity than did conventional diffusion-weighted imaging for assessment of benign and malignant breast lesions. Patients with grade 3 breast cancer or tumors with high expression of Ki-67 were associated with higher kurtosis and lower diffusivity coefficients; however, this association must be confirmed in prospective studies.
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Kun
K
Sun
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Xiaosong
X
Chen
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Weimin
W
Chai
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Xiaochun
X
Fei
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Caixia
C
Fu
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Xu
X
Yan
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Ying
Y
Zhan
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Kemin
K
Chen
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Kunwei
K
Shen
From the Department of Radiology (K.Sun, W.C., Y.Z., K.C., F.Y.), Comprehensive Breast Health Center (X.C., K.Shen), and Department of Pathology (X.F.), Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China; and Siemens MRI Center, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, P.R. China (C.F., X.Y.).
Fuhua
F
Yan
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008875:Middle Aged; D060787:Neoplasm Grading; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult