| Part 1:Title: Clinical Application of Diffusion-Weighted Imaging with ASSET Technique for Breast LesionsPurpose To explore the tehnical feasibility of DWI with ASSET (array spatial sensitivity encoding technique) for patients with breast diseases, and evaluate the diagnosis value of ASSET-DWI in distinguishing benign and malignant breast lesions.Materials and Methods Fifty-six female patients with histologically proven malignant (39 cases with 40 lesions) and benign (17 cases with 20 lesions) lesions in breast and 20 healthy volunteers were selected into this study. MRI was performed with 4-channal phased-array breast coil at 1.5T (GE). Among them, 16 patients and 7 volunteers were performed bilateral breast axial SS-EPI with ASSET technique, conventional SS-EPI, SE TIWI, axial or sagittal FSE T2WI. The imaging quality of ASSET-DWI and the ADC values of normal breast tissues and lesions of patients measured on ASSET-DWI were compared with that of conventional DWI. All patients and healthy volunteers were performed ASSET-DWI with b value being 0, 600s/mm~2 and 0, 1000s/mm~2 to get the ADC values of breast lesions and nomal breast tissues.Results Artifacts can be detected at the border of the breast on the conventional DWI. Among the 16 lesions, 3 displayed distortion, and ADC values cannot be measured in 2 of 3 distortional lesions. The distortion of the breast tissues and lesions were diminished by ASSET-DWI, artifacts resulting from ASSET itself around the breast did not influence the lesions. There is no difference of ADC values between ASSET-DWI and conventional DWI (P>0.05), SNR and CNR decreased slightly (P<0.05). All lesions, except for 1 of fibroadenosis, showed hyperintensity on ASSET-DWI. There is statisticallydifference among the mean ADC value of the malignant lesions, the benign lesions and nomal breast tissues with b=600s/mm2 or b=1000s/mm2 (p<0.05), respectively. The sensitivity of ADC value for malignant lesions with a threshold of less than 1.44xlO"3mm2/s (b=600 s/mm2) or 1.18xlO'3mm2/s (b=1000s/mm2) was 80% (32/40) and 77.5% (31/40), respectively. The specificity of both groups was 95% (19/20).Conclusions ASSET-DWI can be used for breast with decrease of distortion, susceptibility artifacts and acquisition time, SNR and CNR descended slightly. The ADC value with either b=600s/mm or lOOOs/mm can be used to distinguish most malignant lesions from benign ones. The threshold shoud be considered when different b value used in ASSET-DWI. Mucinous adenocarcinoma and intraductal papillomatosis would be prone to pseudo negative and positive outcomes.Title: Clinical Application of Multiphase Contrast-enhanced MR Imaging with VIBRANT for Breast LesionsPurpose To evaluate the clinical value of multiphase contrast-enhanced MRI with VIBRANT (volume imaging for breast assessment) for the diagnosis of breast lesions.Materials and Methods Fifty-three female patients with histologically proven malignant (36 cases with 37 lesions) and benign (17 cases with 20 lesions) lesions in breast were performed bilateral breast axial SE-TIWI, ASSET-DWI, axial or sagittal FSE-T2WI by 4-channal phased-assay breast coil at 1.5T (GE). Axial or sagittal images with VIBRANT covering bilateral breast were acquired with acquisition time about 57 seconds before contrast agent administration. Then multiphase contrast-enhanced MRI followed by 8~10 phases repeat acquisition with no intervals after Gd-DTPA administration with the same parameters and acquisition time used before the injection of contrast agent. The injection ofcontrast agent used the MR injector with a flow rate of 2.0ml/s and dose of 0.1 mmol/kg. The morphologic and kinetic characteristics were observed.Results There were significant differences between the malignant and benign lesions at morphology (p<0.05) and margin (P<0.05) characteristics, the sensitivity was 59.46% and 72.97%, specificity was 80% and 95%, respectively. Enhancement rate of the malignant lesions at 15s after contrast >100% was 67.57%, 70-100% was 24.32%, and <70% was 11.11%. That of benign lesions >100% was 37.5%, 70-100% was 12.5%, and <70% was 50%. The mean enhancement rate of the malignant lesions was higher than that of the benign lesions (p<0.05). The sensitivity and specificity was 91.89% and 65%, respectively. The type I (monophasic) of time-signal intensity curves for malignant leions was 10.81% (4/37), type II (biphasic) was 2.7% (1/37), and typelll (washout) was 86.49% (32/37). The type I for benign lesions was 65% (13/20), type II was 5% (1/20), type III was 10% (2/20), and type IV was 20% (4/20). There was significant difference between the malignant and benign lesions at the distribution of curve types (P<0.05). The dignostic sensitivity and specificity was 89.19% and 85%.Conclusions By means of multiphase contrast-enhanced MRI with VIBRANT covering bilateral breast, better information about morphologic and kinetic characteristics of breast lesions can be acquired. The time-signal intensity curve is useful in differentiating malignant lesions from benign ones. Rapid enhancement and washout time course are main enhancement pattern of malignant lesions. Monophasic time course, ringlike enhancement, ringlike enhancement with smooth mural nodule or no obvious ehancement are that of benign ones. Enhancement rate at 15s after contrast has better sensitivity while spinous margin has better specificity for malignant lesions. Mucinous adenocarcinoma and intraductal carcinoma, lymphoma and intraductal papillomatosis would be prone to pseudo negative and positive outcomes.Part 3:Title: Prediction of Breast Carcinoma Response to Neoadjuvant Chemotherapy using ADC value: Preliminary StudyPurpose To investigate the value of apparent diffusion coefficient (ADC), early change of ADC in predicting the response of breast carcinoma to neoadjuvant chemotherapy.Materials and Methods Sixteen women (total of 17 tumors) from 39 to 62 years old with biopsy proven invasive breast cancer underwent bilateral breast axial SE-TIWI, ASSET-DWI, axial or sagittal FSE-T2WI and contrast-enhanced MRI with VIBRANT prior to neoadjuvant chemotherapy (AT regimen) within 7 days, after the first cycle therapy (during 18-21 days after the treatment) and prior to the surgery resection within 7 days. The primary ADC values (ADCo) of the tumors before the therapy and ADC values after the first cycle therapy (ADCi) were measured on ADC map, respectively. Response to therapy was determined from relative change in tumor volume calculated from enhanced-MRI prior to treatment and before operation respectively. The tumors were divided into response and relative nonresponse group by change of volume. The relationship between the ADC0, aADC (aADC=ADCi- ADCo) and volume after the treatment were analysed.Results The mean ADCi of tumors in response group was increased after first cycle neoadjuvant chemotherapy compared with the mean ADCo (^<0.05), while that in relative nonresponse group with no obvious change (P>0.05). The mean aADC of tumors in response group was higher than that of relative nonresponse group. A significant negative correlation (r=-0.55, f<0.05) was observed between the ADCo and AADCs after the first cycle therapy. There is a significant negative correlation (r=-0.58, f<0.05) between the ADCo and volumes of tumors prior to resection also. The AADCs of tumors after the first cycle therapy were found to correlate significantly (r=0.96, f<0.05) with volume of tumors prior to operation.Conclusions Preliminary results revealed the primary ADC value and early change of the tumor in patient with breast carcinoma may predict rsponse to neoadjuvant chemotherapy. |
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