| Part I The differential diagnostic value of 3T MR quantitative T1 perfusion in breast lesionsObjective: To evaluate the value of quantitative T1 perfusion parameters at 3T MRI with high temporal resolution in the diagnosis of breast lesions.Methods: Select 83 patients with breast lesions who were detected by clinical examination, ultrasound or X-ray from Oct. 2014 to Feb. 2015 in Hebei Tumor Hospital, taken the T1 WI perfusion examination with high temporal resolution.16 patients who were going for neoadjuvant chemotherapy were exclude. Finally, 67 patients who were used to be healthy and were confirmed with pathologically in one week, female and age range from 28 to 62 years old were included.Using Siemens Magnetom Skyra 3.0T MR scanner after conventional scanning, firstly scanning the original image of T1 that is using multiple Tl flip angle technique(TR/TE 5.64ms/2.46 ms, FOV 338x380 mm, matrix 196px320, thickness 2.5mm, layer from 0.5mm, flip angle of 5°/10°/12°15°), then using T1 enhanced continuous sequence(the same sequences as T1 map with flip angle 12°, the total scan times of 70, the first data collection phase 17.3s, then single-phase scan time of 4.58 s, the total time 5min33s). When the beginning of the first data collection phase, vein injection of contrast agent Gadodiamide(GE, USA) 15 ml under high-pressure, 15 ml of physiological saline after the injection, the flow rate was 2.5ml/s.All data were transmitted to GE Omni Kinetics Manual post-processing software. For the measurement of the perfusion parameter of the tumor, select the substantive and enhanced component of the carcinoma as region of interest(ROI). At least three ROI were measured from each lesion, avoiding blood vessels, calcification, fat, empty, necrotic tissue and so on. The range were as big as possible, then access the contralateral normal breast as ROI using the same measurement. Select the aorta as the arterial input function and Extended Tofts Linear model to obtain the following quantitative parameters: ①volume transfer constant(Ktrans), refers to the velocity constant which means that the contrast agent transfer from the intravascular to the extravascular by diffusion. ②rate constant(Kep), refers to the velocity constant which means that after some time, the contrast agent within the interstitial space back intravascular by diffusion. ③extravascular extracellular volume fraction(Ve), is the extravascular extracellular space accounted for the entire voxel volume ratio. Take three ROI of vascular permeability parameters average as the result of the lesions, and at the same time show the pseudo-color map. According to pathology results, the mean Ktrans, Kep and Ve of malignant, benign and normal glandular tissues were calculated. Additionally, the areas under the ROC curve of Ktrans, Kep and Ve between malignant and benign lesions were compared.Results:1 Distribution according to pathological resultThere were 57 patients in normal glandular tissue avoiding 10 fat gland. There were 19 lesions in benign group including intraductal papilloma(3 cases), atypical hyperplasia(5 cases), fibroadenoma(8 cases), hyperplasia of mammary adenosis(3 cases). There were 51 lesions in malignant group. They were ductal carcinoma in situ including microinvasion(5 cases), invasive ductal carcinoma(40 cases), medullary carcinoma(3 cases), invasive micropapillary carcinoma(2 cases) and phyllodes carcinoma(1 cases).2 Difference analysis of quantitative parameters among normal glandular tissue,benign lesions and malignant lesionsThe mean Ktrans, Kep and Ve of normal glandular tissue were(0.012±0.002)min-1,(0.439±0.181)min-1,(0.045±0.013). The mean Ktrans, Kep and Ve of benign lesions were(0.049±0.012)min-1,(0.588±0.217)min-1,(0.107±0.044). The mean Ktrans, Kep and Ve of malignant lesions were(0.154±0.041)min-1,(1.220±0.534)min-1,(0.134±0.054). The difference of mean Kep between malignant and benign lesions were statistically significant(P<0.05). The difference of mean Kep, Ktrans between malignant lesions and normal glandular were statistically significant(P<0.05). The difference of mean Ktrans, Ve between normal glandular and benign lesions was statistically significant(P<0.05).3 Difference analysis of quantitative parameters among intraductal carcinoma, grade II invasive ductal carcinoma and grade III invasive ductal carcinomaThree groups were divided in ductal carcinoma, that is ductal carcinoma in situ(5 cases, including microinvasion), invasive ductal carcinoma of grade II(27 cases) and invasive ductal carcinoma of grade III(12 cases). Invasive ductal carcinoma of Grade I wasn’t in our group because of only one patient. The mean Ktrans, Kep and Ve of ductal carcinoma in situ(including microinvasion) were(0.087±0.042)min-1,(0.869±0.362)min-1,(0.087±0.033). The mean Ktrans, Kep and Ve of invasive ductal carcinoma of grade II were:(0.107±0.037)min-1,(1.245±0.603)min-1,(0.085±0.034). The mean Ktrans, Kep and Ve of invasive ductal carcinoma of grade III were:(0.113±0.047)min-1,(1.363±0.578)min-1,(0.085±0.028). While the differences of mean Ktrans, Kep, Ve among three groups of ductal carcinoma were not statistically significant(P>0.05).4 Area under ROC curve, the best diagnosis value, the sensitivity, and specificity of quantitative parameters between benign lesions and malignant lesionsThe area under the ROC curve of Ktrans, Kep and Ve between malignant and benign lesions were 0.774, 0.819 and 0.491 respectively. And the sensitivity were 64.7%, 68.6%, 54.9%. The specificity were 78.9%, 94.7%, 52.6%, if the maximum Youden’ index was taken as cut-off. The cut-off of Ktrans, Kep and Ve between malignant and benign lesions were 0.074min-1, 0.861min-1 and 0.079.Conclusions: With temporal resolution of 4.58 s, quantitative T1 perfusion parameters at 3T MRI improved the veracity of diagnosis in breast lesions. The differentiation of benign from malignant breast lesions by Kep is applicable, and it shows great efficacy. Part II The correlation between 3T MR quantitative parameters with MVD,VEGF in breast carcinomaObjective: To discuss the correlation of quantitative T1 perfusion parameters at 3T MRI with high temporal resolution and MVD, VEGF for breast carcinoma.Methods: Select 30 patients with breast carcinoma confirmed with pathologically in one week from Oct. 2014 to Feb. 2015 in Hebei Tumor Hospital, taken the T1 WI perfusion examination with high temporal resolution. All were female and age range from 28 to 62 years old. The inclusion criteria, examination methods and quantitative date processing were the same as part I. Wax blocks and slices were selected and stained for HE, anti-VEGF, anti-CD34. CD34 was used for microvessel quantification. Microvessel density was calculated according to a reported method called Weidner. Vascular endothelial growth factor expression was evaluated by a previous method called Manem. The correlation between quantitative T1 perfusion parameters and the expression of MVD, VEGF were performed.Results: The mean Ktrans, Kep and Ve of 30 patients were(0.183±0.081)min-1,(1.192±0.122)min-1,(0.167±0.067). The amount of MVD was 34.96±9.86. The perfusion parameters Ktrans, Kep and Ve were positive correlated with MVD and VEGF(P<0.5), especially Kep(r>0.6).Conclusions: The parameters of T1 weighted perfusion imaging of breast tumors can be used to evaluate the expressions of MVD and VEGF, especailly Kep. So quantitative parameters can give additional information as regards vascularization of breast tumors, useful in the characterization of breast lesions doubt at DCE-MRI and also in monitoring biotherapic effect. |
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