The Application Value Of CT,MRI Normal Examination And CT Perfusion Imaging For The Preoperative Assessment Of T2/T3 Staging In Rectal Cancer

Part I : The application value of CT, MRI normal examination for the preoperative assessment of T2/T3 staging in rectal cancer Objective:This study was design to analyze and evaluate T2/T3 imaging findings with patients' respective characteristics and clinical pathologic comparison, compared the diagnosis consistency of CT and MRI in T2/T3 staging rectal cancer, and further used ROC curve to compare capable of identifying CT, MRI, CT + MRI in the T2 /T3 staging rectal cancer.Materials and methods:Suspected cases with rectal cancer in our hospital were collected form August2014 to July 2015,all patients were cleaned enema before scanning. After injecting water 500-1000 ml through the anus, CT scan used the Toshiba Aquilion 640multi-slice computed tomography(MSCT) perform abdomen plain scan and enhanced scan. Performing MRI scan within three days,MRI used GE 3.0T with 8channel phase array coil without injecting water through the anus. The axial, sagittal and coronal scanning were performed with multiple sequences, contrast-enhanced scan was performed by the quick scan mode,and blus with contrast agent(Gd-DTPA)through cubital vein at once, injection rate:2ml/s.Selected T2/T3 patients with high image quality(n=34).CT and MRI images of68 patients were classified into one of the five possible classifications by two experienced radiologists respectively:(1) definitely positive(2)suspicious positive(3)unidentifiable(4)suspicious negative(5) definitely negative.It was definitely positive that image finds of one case completely accorded with T3 staging, otherwise it wasdefinitely negative. when the diagnosis was ambiguous, it was determined after discussion together,the results were compared with pathological staging and used statistical software SPSS17.0, ROCKIT0.9B to explore preoperative consistency of MRI, CT with T2/T3 staging. Meanwhile,using the area under the ROC curve to compare their ability of identifying T2/T3 staging rectal cancer with CT,MRI,CT+MRI and check whether the st-atistical differences(P<0.05).Results:For T2 staging rectal cancer, CT and MRI can't believe the existence of consistency(Kappa= 0.09, P =0.27); For T3 staging rectal cancer, there was consistency, but consistency is poorer(Kappa= 0.29, P = 0.01). Software ROCKIT0.9B was used to get the ROC curve and the area under the curve(Az) of two examinations, CT and MRI were 0.738 ±0.064, 0.753 ±0.063. Both of them on the identification of T2/T3 staging rectal cancer have a certain accuracy, but CT and MRI in differentiating T2/T3 colorectal cancer had no obvious statistical difference(P = 0.780 > 0.05),it still cannot think that MRI diagnosis efficiency is higher than CT in this study. integrated diagnosis value of combining CT with MRI in T2, T3 rectal cancer was 0.865 ±0.456, it was higher than that of CT or MRI respectively(0.738 ± 0.064, 0.064 ± 0.063), and P < 0.05,(0.0007, 0.0008).Conclusions:To identify T2 as T3 staging in rectal cancer is a common existing problems of CT and MRI; Although CT and MRI had certain accuracy for distinguishing form T2/ T3 rectal cancer, but bad consistency; It was beneficial for improve the ability of identification of CT and MRI with preoperative examination in T2 / T3 rectal cancer preoperative examination that the image data of CT and MRI was considered.Part II: Value of CT perfusion imaging for preoperative T2 / T3 staging in rectal cancer Objective:Through perfusion analysis software of Toshiba 320 row Aquilion one spiral CT,to explore the difference of perfusion parameters in T2 / T3 staging rectal cancer difference, obtain the best diagnostic point with the perfusion parameters.Materials and methods:Suspected cases with rectal cancer in our hospital were collected form August2014 to July 2015, there was sufficient bowel preparation before scanning, to select T2/T3 staging patients with high image quality(n=25). CT perfusion scan method:Pelvic scan firstly, and manually set perfusion scanning range according to lesion's range of the plain scan. Scanning program used Toshiba body tumor scan protocol,to start scanning after 10 seconds with contrast medium injection, each phase interval of 2 s, 3 s, 5 s, scan last 76 s. Tube voltage=100 KV, tube current=100MA.The original perfusion images uploaded to the Vitrea 6.3 workstation.Using Toshiba post-processing workstation with Body perfusion software(Body perfusion)analyzed data, and two high qualification doctors applied the software to perform independent measurement. The obtained data included AF, BV, BF, PS, perfusion parameters were analyzed using SPSS17.0 software, the results were shown with±s by independent sample T-test. Meanwhile, ROCKIT0.9B software was employed to compare each parameters' abilities of identifying the T2 / T3 stage rectal cancer, and determine optimal diagnosis value.Results:Independent samples t test results of perfusion parameters showed that except the arterial blood flow(AF), BV, BF, PS were statistically significant, P=0.010,0.000, 0.000(P < 0.05). BV, BF, PS value existed differences in T2 / T3 stage rectal cancer, and BV, BF value declined with the increase of rectal cancer infiltration degree, the value were 34.35± 2.97, 32.41± 2.08( 100 ml/g) and 24.50±3.15,16.72±3.40(ml / 100 g/min). PS value increased, from 5.27 ±1.11 to 6.61 ±1.23(ml/ 100 g/min)BF value was higher accuracy in identifying T2,/T3 stage rectal cancer(Az value = 0.951 > 0.9), the PS value was certain accuracy(Az value = 0.802 > 0.7),The BV values was low accuracy(Az value = 0.694 < 0.7). The best diagnostic boundary values of CT perfusion parameters with BF, PS in distinguishing T2 / T3 stage rectal cancer were 21.95 ml / 100 g/min, 6.15 ml / 100 g/min.Conclusions:The diagnostic value of AF, BV wasn't obvious for preoperative assessment of T2/T3 staging in rectal cancer; BF, PS had a certain value, BF value declined with the increase of rectal cancer infiltration degree, PS value increased; in distinguishing T2 / T3 stage rectal cancer BF had high accuracy, the best diagnostic boundary values were 21.95 ml / 100 g/min, PS had certain accuracy, the best diagnostic boundary values were 6.15 ml / 100 g/min.