Evaluation of Reperfused Myocardial Infarction by Low-Dose Multidetector Computed Tomography Using Prospective Electrocardiography (ECG)-Triggering: Comparison with Magnetic Resonance Imaging

PURPOSE: To evaluate the potential of prospective electrocardiography (ECG)-gated 64-slice multidetector computed tomography (MDCT) for evaluation of myocardial enhancement, infarct size, and stent patency after percutaneous coronary intervention (PCI) with stenting in patients with myocardial infarction. MATERIALS AND METHODS: Seventeen patients who were admitted with acute myocardial infarction were examined with prospective ECG-gated 64-slice cardiac MDCT and magnetic resonance (MR) imaging after reperfusion using PCI with stenting. Cardiac MDCT was performed with two different phases: arterial and delayed phases. We evaluated the stent patency on the arterial phase, and nonviable myocardium on the delayed phase of computed tomography (CT) image, and they were compared with the results from the delayed MR images. RESULTS: Total mean radiation dose was 7.7 +/- 0.5 mSv on the two phases of CT images. All patients except one showed good patency of the stent at the culprit lesion on the arterial phase CT images. All patients had hyperenhanced area on the delayed phase CT images, which correlated well with those on the delayed phase MR images, with a mean difference of 1.6% (20 +/- 10% vs. 22 +/- 10%, r = 0.935, p = 0.10). Delayed MR images had a better contrast-to-noise ratio (CNR) than delayed CT images (27.1 +/- 17.8% vs. 4.3 +/- 2.1%, p < 0.001). CONCLUSION: Prospective ECG-gated 64-slice MDCT provides the potential to evaluate myocardial viability on delayed phase as well as for stent patency on arterial phase with an acceptable radiation dose after PCI with stenting in patients with myocardial infarction.

Expression of p27Kip1 Protein and Correlation with Clinicopathologic Factors in Colorectal Carcinoma

PURPOSE: The p27Kip1 gene has been recognized as a negative regulator of the cell cycle and a potential tumor suppressor gene. Reduced expression of the p27Kip1 protein has been reported in several human tumors and has been associated with a poor prognosis in breast, lung, colon, prostate, bladder, esophageal and gastric cancers. In the present study, we assessed p27 expression in patients with colorectal cancer in relation to their clinicohistological parameters. METHODS: We investigated p27 expression in 80 patients with colorectal cancers using immunohistochemical staining and the results were analyzed regarding the survival and clinicopathological parameters. RESULTS: Among 80 cases of clolorectal carcinomas, p27Kip1 expression was detected in the nuclei of tumor cells in 48 cases (60%). With the exception of differentiation (p<0.01), no significant correlation was found between p27Kip1 and TMN stage, lymph node metastasis, depth of tumor invasion or overall survival. CONCLUSION: The results suggest that reduced expression of p27Kip1 protein plays a role in the differentiation of colorectal carcinoma and may be a potential prognostic factor. But, more studies are reqired in order to determine whether p27Kip1 protein expression is a clinically valuable prognostic factor.