| Objective:To investigate the value of optimized magnetic resonance imaging scan in predicting T stage and circumferential resection margin involvement of rectal cancer before operation.Material and Methods:44 patients with rectal cancer between October 2013 and May 2014 and 40 patients with rectal cancer between October 2014 and May 2015 were assessed by traditional sequences and optimized sequences respectively. The T stage and the condition of circumferential resection margin involvement were given by two chief radiologists who had received professional training uniformly, which were compared with pathology. Then the accuracy rate of T staging and circumferential resection margin involving were assessed by Chi-square test respectively, and concordance between imaging and pathology was assessed by means of Kappa statistic.Results:T staging:The accuracy rate of traditional sequences and optimized sequences were 52.3%(23/44) and 87.5%(35/40) respectively, with a significant difference (x2=12.166, p<0.05). There was a poor concordance between imaging and pathology of traditional sequences (kappa=0.257, p<0.05), and there was a better concordance between imaging and pathology of optimized sequences (kappa=0.772, p<0.05). Circumferential Resection Margin involving:The accuracy rate of traditional sequences and optimized sequences were 68.2%(30/44) and 92.5%(37/40), with a significant difference (χ2=7.676, p<0.05). There was a poor concordance between imaging and pathology of traditional sequences (kappa=0.319, p<0.05), and there was a better concordance between imaging and pathology of optimized sequences (kappa=0.625, p<0.05).Conclusion:Compared with traditional sequences, optimized sequences can improve the accuracy rate of T staging and circumferential resection margin involving of rectal cancer before operation, and thus help to select treatment, predict efficacy and prognosis.Objective:To investigate the value of IVIM MRI in preoperative T/N staging and differentiation grading of rectal cancerMaterial and Methods:37 patients with rectal adenocarcinoma confirmed by pathology underwent Multi-b value diffusion weighted imaging scan before surgery, with 15 b values (10,20,30,40,60,80,100,150,200,400,800,1000,1200,1500,2000sec/mm2). Post-processing was committed in work station. Three region-of-interests (ROIs) were selected by two radiologists who had received professional training uniformly, then the average value of standard apparent diffusion coefficient (ADC), pure molecular diffusion (D), perfusion-related diffusion (D*) and perfusion fraction (f) were calculated. In all patients, surgery was performed without neoadjuvant therapy. The differences between the histopathologic parameters were assessed by using one-way ANOVA and t-test (for normally distributed data) or Rank sum test (for non-normally distributed data). The histopathologic parameters included A (Al:T1-2 stage; A2:T3-4 stage), B (B1:lymph nodes without involvement; B2:lymph nodes involvement), C (C1:well differentiated; C2: moderately differentiated; C3:poorly differentiated).Results:Mean standard ADC values of C1, C2 and C3 were (1.082±0.090)×10-3mm2/s, (1.031±0.103)×10-3mm2/s and (0.974±0.114)×10-3mm2/s respectively, without a significant difference (F=2.509, P=0.096), but there was a significant difference between Cl and C3 (t=2.217, P=0.033) by Contrast Tests. Mean D values of C1, C2 and C3 were (0.946±0.119)×10-3mm2/s, (0.806±0.092)×10-3mm2/s and (0.671±0.081)×10-3mm2/s respectively, with a significant difference (F=19.393, P=0.000), and there were significant differences between Cl and C2, C2 and C3, C1 and C3 (t=3.440,3.704,6.197, P=0.002, 0.001,0.000) by Contrast Tests. There were no significant differences in standard ADC, D, D* or f values among the rest groups, while we notice that standard ADC and D values decrease as well as f value increase with the elevation of stage and grade.Conclusion:The values of standard ADC, D and f correlate with extent of malignancy and aggressiveness of rectal cancer, and the value of D could reflect the differentiation grade more accurately compared with standard ADC. I VIM MRI helps to predict the prognosis of tumor to some extent. |
PDF Full Text Request