Study Of MR Imaging Of Female Genital System Tumors

Part â…  MR imaging of female genital system tumors with pathologiccorrelationObjective:To analyze and summarize the MRI features of female genital system tumors, to evaluate the role of MRI in diagnosing uterine and ovarian tumors. Material and Methods:MRI findings of normal female pelvic in 20 patients, aged 13 years⁶8 years with a mean of 38 years,and femal pelvic masses in 114 patients(202 lesions), aged 9 years⁸3 years with a mean of 55 years, were analyzed. Of pelvic masses, 54 were originated from the uterine, included 39 cases of benign tumors and 15 cases of malignant tumors, 90 were originated from the ovary, included 58 cases of benign tumors and 32 cases of malignant tumors. MRI scanning use T₁WI-TSE,T₂WI-TSE,T₂WI-STIR and Gd-DTPA enhanced T,WI-TSE - FS sequences in the axial,sagittal and coronal planes. Resultes were compared with histopathology and clinical follw-up. Imaging of the normal female pelvis were evaluated with regard to overall image quality and the ability to detect normal anatomic structures. Evaluate MR imaging in the rate of detection of uterine and ovarian lesions, diagnostic accuracy, sensitivity ,specificity, positive predictive value and negative predictive value. Result: Combined sagittal and axial planes T2WI-TSE imaging provided the most optimal scanning protocol in the assessment of uterine tumors. Combined axial and coronal planes T2WI-TSE imaging provided the most optimal scanning protocol in the assessment of ovarian tumors. For both T2WI-TSE and T₂WI-STIR image set , constrast-to-noise ratios(CNR) were calculated for the myometrium, junctional zone, and endometrium. The endometrium-junctional zone CNR and myometrium-junctional zone CNR were statistical significance(p<0.05). With Gd-DTPA enhanced MR, the enhancement index between benign and malignant tumors were statistically significant(p<0.05).The rate of detection of uterine and ovarian lesions was 93.1%,the diagnosic accuracy, sensiyivity, specificity, positive predictive value and negative predictive value in MRI were 95.7%, 94.6%,96.2%,93%,and 96.9% respectively. Conclusion:Many kinds of MRI scanning sequences and planes are important for the assessment of normal female genital organs anatomy. MRI signal and enhanced scanning sequences can demonstrate thestructure and blood supply of the tumors, and can provide an excellent rate ofdetection ,accuracy and specificity in the assessment of uterine and ovarianpathologies.Part II Value of dynamic enhanced MR imaging in the diagnosisof female genital system tumorsObjective: To evalute the value of three-dimensional(3D) dynamic enhanced MRI in the differential diagnosis of uterine and ovarian tumors. Material and Methods: Dynamic enhanced MRI findings in 106 patients , aged 24 years⁷5 years with a mean of 51 years, were analyzed. Of pelvis masses, 57 were originated from the uterine, included 44 cases of benign tumors and 13 cases of malignant tumors,58 were originated from the ovary, included 19 cases of benign tumors and 39 cases of malignant tumors .The signal intensity of the solid component of tumor was measured. Peak and slope value of enhancement were determined from time-signal intensity curve(TIC). The enhancement rate(ER) of early phase, the time to peak(TTP) of enhancement, and the slope value of TIC were also evaluated. Evaluate dynamic enhanced MRI in diagnostic accuracy, sensitivity specificity, positive predictive value and negative predictive value. Result:The TIC types in the uterine and ovarian tumors were all statistically significant(p<0.05).The ER,TTP,and the slope value of the benign uterine rumors were(185.51±40.84)%,(139.64±42.44)s and (9.09±1.65) respectively, while those of malignant uterine tumors were (217.71 ±32.08) %, (93.77±23.90)s and (11.36±2.41) respectively. The difference of the ER,TTP and slope value between benign and malignant uterine tumors was statistically significant(p<0.05).Using ROC curve plotting obtained the best decisive threshold with ER^215.62%,TTP^92s, sloped 10.71,and the diagnosic accuracy, sensiyivity, specificity, positive predictive value and negative predictivevalue in MRI were ER : 69.2% , 85.0%, 81.1%, 60.0%, 89.5%;TTP: 76.9%, 82.5%, 81.1%, 58.8%, 91.7%;Slope: 61.9%, 85.7%, 83.7%, 80.0%, 67.9%,respectively. The ER,TTP,and the slope value of the benign ovarian tumors were (89.20±51.20) %, (194.70±37.25)s and (3.49±0.91) respectively, while those of malignant ovarian rumors were (196.85±47.07)%, (98.17±29.42)s and (9.56±2.42), respectively. The difference of the SI,TTP and slope value between benign and malignant ovarian tumors wasstatistically significant(p<0.05).Using ROC curve plotting obtained the best decisive threshold with ER^ 118.02 %, TTP ^ 129s > Slope ^ 6.29,and the diagnosic accuracy,sensiyivity,specificity,positive predictive value and negative predictivevalue in MRI were ER : 97.4%, 94.7%, 96.6%, 97.4%, 94.7%;TTP: 87.2%, 90% , 87.9% , 94.4% , 78.3%;Slope : 97.4% , 100% , 98.3% , 100% ,95.0%,respectively.Conclusion:The benign tumors mainly showed type I or II enhancement curve,with low and delay enhancement ,while the malignant tumors mostly showed type III enhancement curve, with high and early enhancement.The three-dimensional dynamic enhanced MR imaging was helpful in the differential diagnosis of female genital bengin and malignant tumors. Part m study of diffusion-weighted imaging (DWI) of femalegenital system tumorsObjective: To evalute the value of diffusion weighted imaging (DWI) and apparent diffusion coefficients(ADC) in the distinguishing benign and malignant uterine and ovarian lesions. Material and Methods:30 leiomyoma ,13 uterine malignant tumors, and 68 cystic ovarian tumors (83 lesions including 20 ovarian cysts, 15endometrial cysts, 6 dermoid cysts, 10 serous cystadenomas , 7 mucinous cystadenomas and 25 malignant cystic ovarian tumors) were studied. The ADC value were calculated in the myometrium, uterine and ovarine lesions. Evaluate ADC value in diagnostic accuracy, sensitivity specificity, positive predictive value and negative predictive value. Result:The malignant lesions dispayed hyperintensity on DWI (b=1000 s/mm2) .ADC value in myometrium, leiomyoma and uterine malignant rumors were 1.62±1.42XI0³mm2/S> 1.18 +1.73 X 10³mm2/S, 1.09 + 0.73 X 10 W/S, respectively, with /?<0.05. But there were no statistical significance(p>0.05) between leiomyoma and uterine malignant tumors .ADC value in ovarian cysts, endometrial cysts, dermoid cysts,serous cystadenomas, mucinous cystadenomas and malignant cystic ovarian tumors were 2.88 + 0.18 X 10³mm2/S, 1.07±0.16X10³mm2/S, 0.87 + 0.56X 10³mm2/S, 2.78±0.10X 10³mm2/S, 2.25 ±0.69X10"3mm2/S, 2.12 + 0.13 X 10"3mm2/S. Ovarian cysts showed highest ADC values than other cystic ovarian lesions.There were no significant ADC difference among ovarian cysts and serous cystadenomas (p>0.05). endometrial cysts, dermoidcysts showed lower ADC values than other cystic ovarian lesions(p<0.05). The ADC values between the benign cystic lesions and malignant cystic ovarian tumors were statistical significance(p<0.05),except for between the malignant cystic ovarian tumors and mucinous cystadenomas (p>0.05).The cutoff value of ADC was 2.18 X 10 3mm2/S,and the diagnosic accuracy,sensiyivity,specificity,positive predictive value and negative predictivevalue in ADC value were 90.3%, 84.0%,91.9%, 87.5%,89.5%,excepting endometrial cysts, dermoid cysts. The diagnosic accuracy,sensiyivity,specificity,positive predictive value and negative predictivevalue in ADC value were 66.3%,84.0%,58.6%,46.7%,89.5%, including endometrial cysts, dermoid cysts. Conclusion:Diffusion-weighted MRI is a feasible method in detecting malignant lesions including metastatic nodes and lymph node. Whlie the ADC values is not useful for uterine bengin and malignant tumors , the ADC values measurement possibly of use in monitoring of treatment response, and possibly of use in evaluating cystic contents of ovarian lesions.Compare with conventional MRI and dynamic enhanced MRI, ADC values is not better than the former, and can complement the former. Part IV study of perfusion diffusion-weighted imaging (PWI)of female genital system tumorsObjective: To assess the diagnostic value of contrast enhanced perfusion weighted MR imaging technique in differential diagnosis between benign and malignant uterine and ovarian neoplasms. Material and Methods: Perfusion weigthed MRI findings in 90 patients, aged 26 years⁷3 years with a mean of 48 years, were analyzed. Of pelvic masses, 51 were originated from the uterine, included 40 cases of leiomyoma and 11 cases of malignant tumors,49 were originated from the ovary,included 16 cases of benign tumors and 33 cases of malignant tumors .The steepest slope of the SI-T curve of the highest perfusion area(SSmax) were calculated. Result: The difference in SSmax between leiomyoma and uterine malignant tumors had no statistically significance(p>0.05). The SSmax of the benign ovarian rumors were (6.78±4.14)%/s,while of malignant ovarian tumors were (18.43±7.O9)co/s. The difference of the SSmax between benign and malignant ovarian tumors was statistically significant(p<0.05).Using ROC curve plotting obtained the best decisivethreshold with SSmax ^ 9.08 % /s ,and the diagnosic accuracy,sensiyivity,specificity,positive predictive value and negative predictive value in MRI were 94.1%,76.9%,86.7%,84.2%,90.9%. Conclusion: PWI can reflect the vascularity of tissue. SSmax could be used as a quantitative parameter to differentiate between benign and malignant ovarian neoplasms. Nevertheless with extensive overlap between leiomyoma and malihnant uterine tumors, SSmax can't be used as a parameter to distinguish leiomyoma from malihnant. PWI can reflect the tumor angiogenesis , and may complement the conventional MRI.