Study Of Ct Diagnosis And Ct Perfusion On Female Pelvic Tumors And Tumor-like Lesions

【Objective】1,CT manifestations of 419 female cases with pelvic tumors or tumor-like lesions were retrospectively analyzed to investigate the value of CT plain and enhanced scanning in diagnosis and differential diagnosis between benign and malignant lesions.2,29 female patients with pelvic tumors or tumor-like lesions were performed with CT perfusion imaging.Various CT parameters between benign and malignant pelvic tumors were compared in order to investigate the value of CT perfusion imaging in differential diagnosis between benign and malignant lesions in female pelvis.Part One:CT diagnosis and differential diagnosis of tumors and tumor-like lesions in female pelvis【Materials and Methods】1,Subjects419 female patients with pelvic tumors or tumor-like lesions in Nanfang Hospital during January 2002 to March 2008 were collected,which ranged in age between 16 and 84 years,with an average age of 45.35 years.2,Equipment and contrast medium(1) Siemens Somatom Plus 4 scanner or GE lightspeed 16 multi-row scanner.(2) KMP810P high pressure syringe(Medrad corp.).(3) Nonionic iodinated contrast agent 300mgI/ml.(4) GE AW 4.2 workstations and PACS network system were used for Image post-processing.3,Examination technique(1) All the patients drunk orally 800ml 1-2%Iohexol(碘海醇) 12 hours before scanning in order to fill the small intestine.Then,150ml 1%Iohexo was used as enema to fill the rectum and sigmoid colon after cleaning.The patients should fasting for 4-6hours and drink 800-1000ml water to fill bladder before starting CT scanning.(2) The patient was on his supine position.Axial scanning was performed continuously from the bottom of pubic symphysis to the upper border of lesions,and the field should be extended according to tumor size.(3) The parameters of single spiral CT were as followings:140K,206mA, 8.0mm slice thickness with 1.0 pitch.Then,80-100ml non-ionic contrasted medium was injected intravenously by 2.0～2.5ml/s velocity.Contrast enhanced scanning started with 20sec delay time.The parameters of 16-slice spiral CT parameters were as followings:120K,120-180mA,16×1.25mm detector mode which covered 20cm every circle,1.375:1 pitch,7.5mm reconstruction thickness with minimum 1.25mm. Then,70-80ml non-ionic contrasted medium was injected intravenously by 2.5～3.0ml/s velocity,.Contrast enhanced scanning started with 20-30sec delay time4,Data processing and imaging evaluation All the primitive data were sent to GE AW 4.2 workstation(16-slice spiral CT) for multi-planar reformation and curved-planar reformat after scanning,or sent to PACS network system(single spiral CT) for analysis.Image analysis included the size of the tumors(represented as maximum diameters in cross section),sharpness of the border,the enhanced values and lymph node in Pelvis.5,Statistical MethodSPSS 11.5 software package was applied to statistical analysis.Pearson Chi-Square(χ²) Test was used to compare border,lymph node of Pelvic between benign and malignant tumors.Age,max-diameter in cross section and enhanced value were compared by the means of Independents-Samples T Test.Statistical significance level was set asα=0.05,statistically significant difference was defined as P value less than 0.05.【Results】(1) 419 patients with Pelvic tumors underwent CT scan,in which 67 were benign(15.99%) and 352 were malignant(84%).(2) Benign lesions demonstrated clear margin in 51 cases(76.2%),but malignant tumors demonstrated unclear margin in 323 cases(91.76%).Statistically significant difference was found in mass margin(P=0.000) between benign and malignant tumors.(3) Enlarged pelvic lymph node was not fond in 51 cases(76.12%) with benign lesion,however,enlarged pelvic lymph nodes,often larger than 1.0cm were fond in 339 cases with malignant lesion.Statistically significant difference was found in pelvic lymph node(P=0.000) between benign and malignant tumors.(4) The age of patients with benign tumors was(47.97±13.10 years) Y,with max-diameter in cross section(3.11±1.21) cm,enhanced value(27.51±8.13) Hu. On the other hand,the age of patients with malignant tumors was(51.65±14.07)Y, with max-diameter in cross section(5.68±3.89) cm,enhanced value(31.22±11.02)Hu.Statistically significant difference was found in patients' age(P=0.019), cross-sectional diameter(P=0.000),and enhanced value(P=0.000) between benign and malignant tumors.【Conclusions】1,With faster scanning,higher soft tissue and spatial resolution,spiral CT is a common imaging examination method for tumors or tumor-like diseases in female pelvis.It is easier to distinguish between normal organs in pelvis and tumors or tumor-like diseases by well prepared intestinal tract and well filled urinary bladder.2,By using plain and contrast-enhanced scanning,CT imaging could not only well demonstrate the position,shape and the relationship with surrounding structures, but also clearly show the invasion of lymph node and organs in pelvis.It could give valuable information for tumor stage,treatment and therapeutic effect in clinic.3,Our research indicated that statistically significant differences existed in tumor borders,pelvic lymph nodes and the enhanced value between benign and malignant masses in pelvis.Benign tumors often showed as clear margin(51/67),no metastatic lymph node(51/67),but malignant tumors often demonstrated as unclear margin(323/352),metastatic lymph node(339/352) with higher enhanced value. CT could give important guiding in the differential diagnosis between benign and malignant lesions in pelvis combing with clinic conditions.Part Two:Study of multi spiral CT perfusion imaging in differential diagnosis between benign and malignant lesions in female pelvis【Materials and Methods】1,Subjects29 patients with pelvic tumors in Nanfang Hospital underwent CT perfusion imaging during 2007/6-2008/3,which ranged in age between 28 and 68 years,with an average age of 47.65 years.2,Equipment and contrast mediumCT perfusion imaging was performed with GE lightspeed 16 multi-row scanner, with others same as that in Part 1.3,Examination technique(1) The preparation of patient:same as that in Part 1(2) Plain CT scanning was as same as that in Part 1,through which the slices for CT perfusion imaging were confirmed.(3) CT perfusion imaging was performed with the axial mode of 5mm×4 slice, with 120Kv,40mA.50ml contrast agent was injected intravenously by 4.0ml/s velocity,then,CT perfusion scanning started in 10 seconds delayed time with 30 times(1 time/1sec,with a interval of 1 sec) in first phase,and 30 times(1 time/sec, with a interval of 3 sec) in the second phase.Altogether 240 images were acquired within 190seconds.(4) After perfusion scanning,routine contrast enhanced scanning was performed after infection of 30ml contrast agent with 2.5ml/s velocity,using the same conditions as that in part one.4,Data processing and imaging evaluationThe original data of CTP was sent to GE AW 4.2 workstation.Data processing was done by using commercially available Perfusion 3 software package on GE AW 4.2 workstation.Firstly we chose a biggest tumor section as the post-processing section.Then,a threshold was adjusted from -200 to 120Hu.And then,choose internal iliac artery as input artery,and confirm the range of interest(ROI).ROI should be chosen as large as possible but not extend out the range of the artery.The ROI in lesion should be chosen in the solid part of the mass as possible as you can but avoiding the area near the tumor border,at same time,avoiding the area near big vessel and cystic,necrotic and calcification area.The time-density curves(TDC) of ROI in artery and lesions were generated automatically by software,and a serial of color maps that representing perfusion index were generated automatically,including blood flow,blood volume,mean transit time,and permeability surface area product.5,Statistical MethodSPSS 11.5 software package was applied to statistical analysis.Each of the perfusion parameters(BF,BV,MTT and PS) was compared between benign and malignant tumors by the Independent -Samples T Test.Statistical significance level was set asα=0.05,statistically significant difference was defined as P value less than 0.05.【Results】(1) 29 patients with pelvic tumors underwent CT perfusion exam,in which 15 were benign(51.7%) and 14 were malignant(48.3%).(2) The TDC of CTP imaging in benign tumors showed as mild ascending segment and flat type,however,the malignant tumors showed as fast ascending segment with mile descending segment.(3)The perfusion parameters of the tumors were as follows:BF of the benign tumors(61.17±31.99)ml.min^-1·100g^-1,BV of the benign tumors(4.60±0.95) ml·100g^-1, MTT of benign tumors(7.77±1.96)s,PS of benign tumors(13.69±3.31) ml·min^-1·100g^-1;BF of malignant tumors(154.81±54.05) ml·min^-1.100g^-1,BV of malignant tumors(6.29±1.05) ml·100g^-1,MTT of malignant tumors(6.44±1.04)s,PS of malignant tumors(17.26±2.67)ml·min^-1·100g^-1.Statistically significant difference was found in BF(P=0.000),BV(P=0.000),PS(P=0.004) and MTT(P=0.031) compared between benign and malignant tumors(P＜0.05). 【Conclusions】1,Pelvis has a fixed position and was hardly effected by breathing which is convenient for CT perfusion study.2,CT perfusion imaging is an non-invasive functional imaging which can evaluate perfusion condition of organism.Our study showed that the perfusion indexes of BF,BV and PS in malignant pelvic tumors were much higher than those in benign tumors,and MTT lower than that of in benign tumors with statistical significance in the differences;which is valuable for differential diagnosis.3,We could obtain both morphology and functional information of pelvic tumors by CT perfusion in one scanning,and it will offer more diagnostic evidences to clinics.Therefore,CT perfusion of pelvic tumors is a promising tool in clinical practice.