| Objective:To analyze the diagnostic value of 3.0T magnetic resonance imaging(MRI)in grading colorectal cancer by evaluating images of the diffusion weighted imaging(DWI)and enhanced scanning,and compare these parameters with postoperative pathological results.Methods:A total of 73 patients with colorectal cancer diagnosed by postoperative pathological were retrospectively enrolled in this study between January 2016 and May 2018.Clinical datas of the patients were retrospectively analyzed.Inclusion criteria included(1)patients who underwent MRI scan,MRI enhanced imaging and DWI preoperatively;(2)patients who did not have radiotherapy and chemotherapy preoperatively;(3)postoperative pathology was adenocarcinoma.The 3.0T MRI was used in all patients.An image post-processing software was employed to evaluate the raw imagings after scanning.The region of interest(ROI)was drawn based on the largest cross-sectional area of the lesion.Solid part of the tumor was measured and avoided necrosis,blood vessels and artifacts of the tumor.Enhancement of lesions were also analyzed by two radiologists with diagnostic experience in MRI.The observed indicators included the morphology,location,and enhancement of lesions(patients were divided into three groups based on the enhancement of the tumor:marked,moderate,and mild)and lesions' ADC values.The pathological results were used as the gold standard,the lesions,gross classification and pathological differentiation of 73 patients were counted.Statistical analyses were performed using SPSS 19.0(SPSS Inc,Chicago,IL).The age and ADC values were presented as mean ± standard deviation.One-way ANOVA was used to compare the relationships of ADC values with tumors' pathological differentiation and locations.Independent sample t test was used to compare the difference of ADC values between male and female groups.Pearson correlation analysis was used to compare the correlation between age and ADC values;chi-square test was used to evaluate the degree of lesion enhancement and lesions in MRI enhanced scan.The correlation between enhancement degree and different pathological types was analyzed by independent sample t test.P<0.05 was considered statistically significant.Using the statistical software to draw the receiver operating characteristic curve(ROC)curve to evaluate the diagnostic role of ADC value in differentiating well differentiated and moderately differentiated tumors,well differentiated and poorly differentiated cancer,moderately differentiated and poorly differentiated tumors.A cut-off value was obtained at the point of Youden index.The area under the curve,sensitivity and specificity were recorded.Results:(1)In the study,47 male patients and 26 female patients were included in the study.The mean age was 61.7 ± 12.2 years,ranging from 28 to 88 years old.The pathological results of the 73 cases with colorectal cancer included 9 well differentiated adenocarcinoma,58 moderately differentiated adenocarcinoma and 6 poorly differentiated adenocarcinoma.The lesions were respectively located at rectum(28 cases),sigmoid colon(24 cases),transverse and descending colon(4 cases),ascending colon and ileocecal(17 cases).The follow-up time was ended to May 31,2018,and the follow-up rate was 100%.(2)The MRI manifestations of colorectal cancer in this group included localized or irregular thicknness of the intestinal wall,intestinal mass and narrow of the lumen in most lesions,stiff walls in some intestinal canal and the blurred fat gap,etc.In most cases,T1WI showed equal signal,T2WI showed slightly higher signal,DWI showed obvious high signal or mixed high signal,ADC showed low signal.Obvious enhancement was most frequently(54.8%)than moderately enhancement(34.2%)and mildly enhancement(11.0%).There was significantly difference among three degrees of colorectal cancer on enhancement.The higher degree of the tumor,the lower enhancement was discovered.(3)The ADC value of 6 patients with poorly differentiated tumor was(0.778±0.148)×10-3mm2/s.The ADC value of 58 participants with moderately differentiated cancer was(0.932±0.160)×10-3mm2/s.The ADC value of 9 patients with highly differentiated tumor was(1.150±0.235)×10-3mm2/s.One-way variance analysis was performed on ADC values of colorectal cancer with different degree.There existed statistically differences in ADC values among different degrees of differentiation.According to the results of ROC curve analysis,the cut-off value between highly differentiated and moderately differentiated adenocarcinoma was 1.051 ×10-3mm2/s with a Youden index of 0.571,the sensitivity was 77.80%and the specificity was 79.30%,the area under the curve was 0.781 with a 95%confidence interval of 0.585-0.976.The cut-off value between highly differentiated and poorly differentiated tumor was 0.994×10-3mm2/s with a Youden index of 0.778,the sensitivity was 77.80%and the specificity was 100%,the area under the curve was 0.926 with a 95%confidence interval of 0.792-1.060.The cut-off value between moderately differentiated and poorly differentiated cancer was 0.801 ×10-3mm2/s with a Youden index of 0.546,the sensitivity was 87.90%and the specificity was 79.30%;the area under the curve was 0.781 with a 95%confidence interval of 0.585-0.976.(4)One-way variance analysis was performed on ADC values of colorectal cancer with different locations.There was no significant difference in ADC values among different sites of colorectal cancer.(5)The mean ADC values of colorectal cancer were respectively(0.927±0.174)×10-3mm2/s and(0.981±0.212)×10-3mm2/s for male and female.There was no significant difference in ADC values of colorectal cancer between different genders in the independent sample t test(P=0.239).(6)Pearson correlation analysis was used to evaluate the correlation between age and ADC values of the colorectal cancer.The results showed that there was no significant correlation between these two parameters.Conclusions:MRI is a better method of evaluating patients with colorectal cancer preoperatively with important value.Combined analysis of lesions' enhancement and ADC values on MRI images has a high accuracy,sensitivity and specificity for judging tumors' preoperative grading,it has an important significance on the evaluation of clinical prognosis.Thus,combined analysis of colorectal cancer preoperatively by MRI should be widely used furtherly. |
PDF Full Text Request