Diffusion-weighted imaging provides a novel contrast mechanism in magnetic resonance (MR) imaging and has a high sensitivity in the detection of changes in the local biologic environment. A significant advantage of diffusion-weighted MR imaging over conventional contrast material-enhanced MR imaging is its high sensitivity to change in the microscopic cellular environment without the need for intravenous contrast material injection. Approaches to the assessment of diffusion-weighted breast imaging findings include assessment of these data alone and interpretation of the data in conjunction with T2-weighted imaging findings. In addition, the analysis of apparent diffusion coefficient (ADC) value can be undertaken either in isolation or in combination with diffusion-weighted and T2-weighted imaging. Most previous studies have evaluated ADC value alone; however, overlap in the ADC values of malignant and benign disease has been observed. This overlap may be partly due to selection of b value, which can influence the concomitant effect of perfusion and emphasize the contribution of multicomponent model influences. The simultaneous assessment of diffusion-weighted and T2-weighted imaging data and ADC value has the potential to improve specificity. In addition, the use of diffusion-weighted imaging in a standard breast MR imaging protocol may heighten sensitivity and thereby improve diagnostic accuracy. Standardization of diffusion-weighted imaging parameters is needed to allow comparison of multicenter studies and assessment of the clinical utility of diffusion-weighted imaging and ADC values in breast evaluation.

OBJECTIVE. The purposes of this study were to compare the apparent diffusion coefficient (ADC) of mucinous carcinoma of the breast with that of other breast tumors and to analyze correlations between signal intensity on diffusion-weighted images and the histologic features of mucinous carcinoma.SUBJECTS AND METHODS. Two hundred seventy-six patients with 277 lesions, including 15 mucinous carcinomas (13 pure type, two mixed type), 204 other malignant tumors, and 58 benign lesions, were examined with 1.5-T MRI at b values of 0 and 1,500 s/mm2. The correlations between cellularity and ADC, homogeneity of signal intensity on diffusion-weighted images, and histopathologic findings were analyzed. The difference was statistically significant (p < 0.05).RESULTS. The mean ADC of mucinous carcinoma (1.8 ± 0.4 × 10-3 mm2/s) was statistically higher than that of benign lesions (1.3± 0.3 × 10-3 mm2/s) and other malignant tumors (0.9 ± 0.2 × 10-3 mm2/s) (p < 0.001). The ADC of pure type mucinous carcinoma (1.8 ± 0.3 × ...

To compare the capability of diffusion-weighted (DW) and contrast material-enhanced magnetic resonance (MR) imaging to provide diagnostic information on residual breast cancers following neoadjuvant chemotherapy and to assess apparent diffusion coefficients (ADCs) of the carcinoma prior to neoadjuvant chemotherapy to determine if the method could help predict response to chemotherapy. Institutional review board approval and informed consent were obtained. Three hundred ninety-eight patients underwent MR imaging of the breast, including DW MR (b values, 0 and 1500 sec/mm(2)) and contrast-enhanced MR imaging. Of these, the contralateral breast in 73 women was used as a control. Seventy-two patients with 73 lesions with malignant disease were treated by using neoadjuvant chemotherapy and were examined for residual disease following therapy. Three were excluded because of prolonged intervals between final MR imaging and surgery. Thus, 69 patients (70 lesions) with DW and contrast-enhanced MR imaging results were compared with postoperative histopathologic findings. The ADCs of the carcinoma prior to neoadjuvant chemotherapy were calculated for each patient, and those with complete response and residual disease were compared. The accuracy for depicting residual tumor was 96% for DW MR imaging, compared with an accuracy of 89% for contrast-enhanced MR imaging (P = .06). There was no significant difference in prechemotherapy ADCs between pathologic complete response cases and those with residual disease. DW MR imaging had at least as good of accuracy as did contrast-enhanced MR imaging for monitoring neoadjuvant chemotherapy. The ADCs prior to chemotherapy did not predict response to chemotherapy. The use of DW imaging to visualize residual breast cancer without the need for contrast medium could be advantageous in women with impaired renal function.

To evaluate the feasibility and usefulness of imipenem/cilastatin sodium (IPM/CS) as an embolic agent for intestinal bleeding from neoplasms. Seven patients who underwent 11 transarterial embolisations (TAEs) using IPM/CS as an embolic material for duodenal or small/large intestinal tumour bleeding from January 2004 to December 2011 were retrospectively evaluated. A mixture of IPM/CS and contrast medium was introduced through the microcatheter positioned at the feeding artery to the tumour until extravasation disappeared or stasis of blood flow to the tumour staining was observed. Haemostasis was obtained in all patients. Therefore, the technical success rate was 100%. Rebleeding was observed in four patients. All of them underwent repeat TAE using IPM/CS, and haemostasis was obtained successfully. No complication was identified following laboratory and clinical examinations. No haemorrhagic death occurred. Haemorrhagic parameters, including blood haemoglobin and the amount of blood transfusion, improved after TAE. The safety, feasibility, and effectiveness of TAE using IPM/CS as an embolic material for intestinal bleeding from neoplasms were suggested by this study. The mild embolic effect of IPM/CS may be adequate for oozing from tumours. Although rebleeding may occur after embolotherapy using IPM/CS, repeat embolisation is effective as treatment for rebleeding.