Differential diagnosis of nodular lesions in cirrhotic liver by post-vascular phase contrast-enhanced US with Levovist: comparison with superparamagnetic iron oxide magnetic resonance images.

BACKGROUND: We investigated the diagnostic utility of post-vascular phase contrast-enhanced ultrasonography (US) and superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) as compared to the histological diagnosis of differential grades of hepatocellular carcinomas (HCCs). METHODS: Forty-nine patients with histologically characterized liver nodules (well-differentiated HCC, n = 20; moderately differentiated HCC, n = 19; poorly differentiated HCC, n = 1; dysplastic nodule, n = 9) received contrast-enhanced US and SPIO-MRI. Subsequently, we quantitatively evaluated the relationships between the images of the nodules and their histological diagnosis and differential grades. RESULTS: The ratio of the echogenicity of the tumorous area to that of the nontumorous area with post-vascular phase contrast-enhanced US (post-vascular phase ratio) decreased as nodules became less differentiated (P < 0.05; Kruskal-Wallis test). The ratio of the intensity of the nontumorous area to that of the tumorous area on SPIO-enhanced MR images (SPIO intensity index) also decreased as nodules became less differentiated (P < 0.01). The post-vascular phase ratio correlated with the SPIO intensity index for HCCs and dysplastic nodules (r = 0.76). The conformity of the result from the post-vascular phase contrast-enhanced US and SPIO-MRI was 96%. CONCLUSIONS: Contrast-enhanced US is a valuable method for predicting the histological grade of HCCs in cirrhotic patients, and may be a good alternative to SPIO-enhanced MRI.

Dynamic multidetector CT of breast tumors: diagnostic features and comparison with conventional techniques.

OBJECTIVE: We sought to analyze the features of breast tumors as revealed on dynamic multidetector CT (MDCT), to develop descriptors for these features, and to compare the performance of MDCT with the performance of other techniques used in the depiction of tumors. SUBJECTS AND METHODS. MDCT was performed in 149 women with suspected breast tumors, and 173 breast lesions were detected. These breast lesions were classified as either mass or nonmass enhancing lesions. For mass lesions, the margin, shape, and enhancement patterns were evaluated. For nonmass enhancing lesions, the distribution of enhancement and the types of time-density curve patterns were evaluated. MDCT was compared with mammography and sonography as a method of revealing breast tumors. RESULTS: Of the 173 breast lesions detected, 150 were mass lesions, 131 (87%) of which were malignant. Of the 23 nonmass enhancing lesions, 21 (91%) were malignant. The most highly predictive features for lesion malignancy were an irregular margin (100%), an irregular shape (99%), and rim enhancement (100%). Similar features were the most accurate signs of malignancy--a spiculated and irregular margin (90%). On time-density curves, the washout and plateau patterns showed high positive predictive value (93%) and sensitivity (91%) for malignancy. However, these patterns had low negative predictive value (42%) and specificity (48%). Seven breast lesions that could not be detected on mammography or sonography were identified on MDCT. MDCT more accurately revealed the margin of the tumor invasion in 11 breast tumors than did mammography or sonography. CONCLUSION: The features revealed on MDCT can help to distinguish benign lesions from carcinomas. MDCT can add to the data obtained with mammography or sonography in patients with suspected breast tumors.