Objective To explore the multi-modal MRI characteristics of breast cancers in dense breasts.Methods 120 patients with breast cancer shown on mammography underwent breast MRI,which were solitary and confirmed by pathological examination. According to the BI-RADS classification of breast,the 120 cases were divided into two groups including dense type breast and non-dense type one.The differences in morphological features,ADC values (b=1 000 s/mm2 )and time-signal intensity curve (TIC)of the lesions between two groups were analyzed and compared.Statistical analysis was performed using SPSS1 6.0.Results The breast cancers in dense breast were vulnerable to have a spiculated margin (44/68 in the dense breast group vs.1 6/52 in the non-dense breast group,P =0.000).The size of the lesion in dense breast (1.83 ±0.98)cm was bigger than that in non-dense breast (1.40±0.46)cm (P =0.005).The non-mass-like enhancement of the lesion in dense breast was much more than that in non-dense breast (P =0.000).In addition,the average ADC values of the lesion in dense breast (0.89±0.12)×10 -3 mm2/s were lower than in non-dense breast (0.95±0.10)×10 -3 mm2/s(P =0.01 6).Conclusion The breast cancer in the dense breast has different MRI findings in comparison with non-dense breast.

Objective To evaluate the value of proton magnetic resonance spectrum (1H-MRS) in the differential diagnosis of Alzheimer's disease (AD) and vascular dementia (VD) patients with white matter lesions (WMLs).Methods Multi voxel 1H-MRS were performed to 30 patients with AD,30 patients with VD,and 30 normal control volunteers.The levels of the N-acetylaspartate (NAA),myo-inositol (mI),glutamate (Glu),and creatine (Cr) were measured in the white matter adjacent to the lateral ventricles.The ratios of NAA/Cr,mI/Cr and Glu/Cr were calculated and compared among the group.Comparisons of the 1H-MRS indexes among AD,VD and NC group were conducted by one-way ANOVA.Results NAA/Cr ratios of the region of interesting in AD (1.59±0.15)and VD(1.53±0.12) group were significantly decreased compared with NC (1.79±0.22)group (P＜0.05),and Glu/Cr ratios of the region of interesting in AD(0.41±0.03) and VD(0.49±0.04) group were significantly decreased compared with NC(0.57±0.05) group (P＜0.05).However,there were not significant differences for NAA/Cr ratios of the paraventricular white matter region between AD and VD group (P＞0.05),and Glu/Cr ratios in AD and VD groups were significantly different (P＜0.05).A significantly increased mI/Cr was found in AD (0.68±0.05) group than in VD(0.57±0.04) and NC(0.55±0.03) groups (P＜0.05),and there were no significant changes in mI/Cr ratios between VD and NC groups (P＞0.05).Conciusion Multi-voxel 1H-MRS is an effective method in the differential diagnosis of dementia,and changes of the mI/Cr and Glu/Cr ratios of the white matter adjacent to the lateral ventricles may help to identify the AD and VD patients.

Objective To evaluate the application of abbreviated protocol (AP) of magnetic resonance imaging (MRI) in screening of breast cancer with dense breast tissue.Methods Total 478 patients with dense breast tissue,who had negative X-ray mammography (MG),underwent dynamic contrast-enhanced MRI (DCE-MRI).The AP MRI,which consisted of first postcontrast subtracted (FAST) and maximum-intensity projection (MIP),and full diagnostic protocol (FDP) MRI images were analyzed by Breast Imaging Reporting and Data System (BI-RADS).Among 478 patients the histopathological diagnosis was available in 39 cases (41 breast lesions).With pathological diagnosis as gold standard,the sensitivity,specificity,positive predictive value (PPV) and negative predictive value (NPV) of AP and FDP in breast cancer detection were evaluated.Results In 41 breast lesions there were 16 malignant lesions and 25 benign lesions.FDP detected all 16 malignant lesions,including 9 cases of ductal carcinoma in situ,6 cases of invasive ductal carcinoma and 1 case of mucinous carcinoma;AP detected 15 out of 16 cases of breast cancer.The sensitivity of FDP and AP in detection of breast malignant lesions was 16/16 and 15/16,respectively (x2 =0.725,P =0.224).The specificity of FDP and AP was 92％ (23/25) and 76％ (19/25),respectively (x2 =6.327,P =0.012).Conclusion For women with dense breast tissue AP of MRI can be used in early screening of breast cancer.