Effectiveness of dynamic contrast-enhanced magnetic resonance imaging in evaluating clinical responses to neoadjuvant chemotherapy in breast cancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Use of neoadjuvant chemotherapy necessitates assessment of response to cytotoxic drugs. The aim of this research was to investigate the effectiveness of dynamic contrast-enhanced magnetic resonance imaging (MRI) for evaluating clinical responses to neoadjuvant chemotherapy in breast cancer patients.</p><p><b>METHODS</b>We examined patients receiving neoadjuvant chemotherapy for primary breast cancer between October 2007 and September 2008. Dynamic contrast-enhanced MRI was used to examine breast tumors prior to and after neoadjuvant chemotherapy. The MRI examination assessed tumors using Response Evaluation Criteria in Solid Tumors (RECIST). The Miller-Payne grading system was used as a histopathological examination to assess the effect of the treatment. We examined the relationship between the results of RECIST and histopathological criteria. In addition, we used time-signal intensity curves (MRI T-SI) to further evaluate the effects of neoadjuvant chemotherapy on tumor response.</p><p><b>RESULTS</b>MRI examination of patients completing four three-week anthracycline-taxanes chemotherapy treatment revealed that no patients had complete responses (CR), 58 patients had partial responses (PR), 29 patients had stable disease (SD), and four with progressive disease (PD). The effectiveness of neoadjuvant chemotherapy (CR + PR) was 63.7% (58/91). The postoperative histopathological evaluations revealed the following: seven G5 (pCR) cases (7.7%), 39 G4 cases (42.9%), 16 G3 cases (17.6%), 23 G2 cases (25.3%), and six G1 cases (6.6%). The effectiveness (G5 + G4 + G3) was 68.1% (62/91). MRI T-SI standards classified 53 responding cases, 29 stable cases, and nine progressing cases. These results indicated that the treatment was 58.2% effective (53/91) overall.</p><p><b>CONCLUSIONS</b>Dynamic contrast-enhanced MRI and histopathological standards were highly correlated. Importantly, MRI T-SI evaluation was found to be useful in assessing the clinical effectiveness of neoadjuvant chemotherapy.</p>

CT angiography of pulmonary embolism using a 64 slice multi-detector scanner / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Multi-detector computed tomography (MDCT) has already been the first line investigation method for diagnosis of pulmonary embolism (PE). Reducing the amount of contrast medium used during CT scanning could decrease the incidental rate of adverse reactions. Our study amied to evaluate the image quality of pulmonary arteries using 64 slice multi-detector CT with small volumes of contrast media injection.</p><p><b>METHODS</b>Forty nonconsecutive patients without PE or other lung diseases were randomly assigned to two groups. Group A underwent CT scanning with 16 x 1.25 mm collimation and a 70 ml contrast injection, while group B had CT with 64 x 0.625 mm collimation and 20 ml of contrast injection. Two readers independently depicted the segmental and subsegmental pulmonary arteries. Reasons we could not analyze the pulmonary artery or that led to misdiagnosis of pulmonary embolism were evaluated, including the degree of contrast enhancement of the main pulmonary artery, and factors that caused misdiagnosis of PE (flow-related artifacts, partial volume artifact, beam-hardening artifacts and enhancement of pulmonary vein). The independent samples t-test, Mann-Whitney U test and Pearson chi-square test were applied.</p><p><b>RESULTS</b>There were no significant differences in image quality of segmental and subsegmental arteries between the two groups. No significant difference was found for factors that made pulmonary arteries non-analyzable or in the misdiagnosis of PE, except the degree of contrast enhancement.</p><p><b>CONCLUSION</b>64 x 0.625 mm collimation with 20 ml contrast injection could depict the pulmonary arteries well.</p>