Associations of apparent diffusion coefficient value from MR diffusion-weighted imaging with Ki-67 expression and differentiation grade in gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To examine the associations of apparent diffusion coefficient (ADC) value from MR diffusion-weighted imaging (DWI) with Ki-67 expression and differentiation grade in gastric cancer.</p><p><b>METHODS</b>Images and pathologic data of 68 gastric cancer patients between September 2013 and February 2015 in Affiliated Changshu Hospital of Soochow University were analyzed retrospectively. The expression of Ki-67 antigen in cancer tissue sample was determined by immunohistochemistry. Ki-67 labeling index(LI) was calculated to divide the cases into low Ki-67 group(Ki-67 LI <50%) and high Ki-67 group (Ki-67 LI ≥ 50%). Associations of ADC value with differentiation grade and Ki-67 LI were examined.</p><p><b>RESULTS</b>Mean ADC value of low Ki-67 LI group was significantly higher than that of high Ki-67 LI group [(0.977 ± 0.100) × 10(-3) mm(2)/s vs. (0.859 ± 0.064) × 10(-3) mm(2)/s, P=0.000]. The ADC value was negatively correlated with Ki-67 LI (r=-0.685, P=0.000). Mean ADC value of well differentiated adenocarcinoma, moderately differentiated adenocarcinoma, poorly differentiated adenocarcinoma, and signet-ring cell carcinoma was (1.124 ± 0.080) × 10(-3) mm(2)/s, (0.950 ± 0.064) × 10(-3) mm(2)/s, (0.899 ± 0.091) × 10(-3) mm(2)/s, and (0.894 ± 0.081) × 10(-3) mm(2)/s respectively. Difference of ADC value among differentiation grades was significantly different (F=11.405, P=0.000). Difference of ADC value between well differentiated adenocarcinoma and non-well differentiated adenocarcinoma was significantly different(P=0.000).</p><p><b>CONCLUSION</b>ADC value is associated with differentiation grade and Ki-67 LI of gastric cancer, which may be used as a noninvasive predictor for evaluating the proliferation and differentiation grade of gastric cancer.</p>

Value of diffusion-weighted MRI in the diagnosis of T staging for rectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the value of diffusion-weighted imaging (DWI) in the diagnosis of T staging for rectal cancer.</p><p><b>METHODS</b>Clinicopathologic data and MR images of 46 patients with rectal cancer in our hospital from July 2013 to September 2014 were retrospectively analyzed. The diagnostic sensitivity, specificity and accuracy of T2WI were compared with those of T2WI plus DWI in T staging for rectal cancer. The relationship of mean apparent diffusion coefficient (ADC) value with different T stages of rectal cancer was analyzed.</p><p><b>RESULTS</b>There were no significant differences in the diagnostic sensitivity, specificity and accuracy between T2WI and T2WI plus DWI (all P>0.05). The mean ADC value of DWI performed in pathologic T2, T3a, T3b, T3c and T4 stage was (1.110 ± 0.117) × 10⁻³ mm²/s, (1.035 ± 0.121) × 10⁻³ mm²/s, (0.948 ± 0.109) × 10⁻³ mm²/s, (0.932 ± 0.122) × 10⁻³ mm²/s and (0.843 ± 0.050) × 10⁻³ mm²/s, respectively (F=6.972, P=0.000).</p><p><b>CONCLUSION</b>DWI can serve as a complement for T2WI in the diagnosis of T stage patients with rectal cancer, and its ADC value presents a downward trend with the advance of T stage.</p>