The application of breast DCE-MRI combined with time signal curve in diagnosing early breast cancer

Objective： The aim of this study was to investigate the application value of breast dynamic contrast-enhanced magnetic resonance imaging combined with time signal curve in diagnosis of early breast cancer. Methods： Conducted dynamic contrast-enhanced MRI and drew the time signal curves of breast lesions in 60 patients with breast disease （malignant 46, benign 14）. Results： Morphological features of malignant tumors mostly showed blurred or thin spiculate outlines, irregular shape or Iobular signs, signal heterogeneity or peripheral enhancement in dynamic contrast-enhanced MRI. Time signal curve showed type III or II. Morphologic features of benign tumors mostly showed clear edge, regular shape and homogeneous signal, or diffuse spot enhancement. Time signal curve showed type I or II. Conclusion： breast dynamic contrast enhanced scan in MRI can provide morphology and functional diagnosis information of the breast tissues. Dynamic contrast-enhanced MRI combined with time signal curve can further improve the accuracy of diagnosis of early breast cancer.

Quantitative Assessment of Coronary Flow Reserve by the Variables of Time-Intensity Curve with Myocardial Contrast Echocardiography

The reliability and reliable indexes of q ua ntitative assessment of coronary flow reserve (CFR) by using time intensity cur ve (TIC) via myocardial contrast echocardiography were investigated. The TIC var iables were obtained by employing acoustic densitometry (AD) technique before an d after acetylcholine (Ach) injection in 12 dogs. Meanwhile, the correlation be tween these variables and CFR was analyzed. Among the variables derived from TIC , peak intensity (PI), area under the curve (AUC) and descending slope (DS) were increased significantly ( P <0.05) with the increase of coronary blood flow a fter Ach injection. Conversely, time to peak (TP), half time of descent (HT) , and mean transit time (MTT) were decreased remarkably ( P <0.0001). Th e P I and AUC ratios from post to pre Ach injection were strongly associated with CFR with the correlation coefficient (r) being 0.8366 and 0.8824, respectively. It is reliable by using the variables derived from TIC with myocardial contrast echocardiography to quantitatively evaluate regional myocardial CFR. The PI an d AUC ratios from post to pre Ach injection are the reliable indexes for quan titative assessment of CFR.

Crustal structure and accurate hypocenter determination along the Longmenshan fault zone

A P and S wave velocity model is obtained for the crust in the region along the Longmenshan fault zone, Sichuan Province, China, by using data from a refraction profiling survey carried out in this region and those from local earthquakes. 202 local earthquakes along the fault zone are based on this velocity model, location errors being estimated to be about 1.5 km. The present relocations fairly improved the accuracy of hypocenter locations for earthquakes in this area, which is recognized from small scatter of data in the arrival time distance diagram compared with that for the original locations in the Earthquake Catalogue of Sichuan Seismic Network. The obtained hypocenter distribution shows that shallow earthquakes, confined to the upper crust in the depth range from 3 km to 22 km, are actively occurring along the main fault of the Longmenshan fault zone. The velocity model and the location method are presently used quite effective for precisely locating local earthquakes such as those in Sichuan Province. Installation of these with the real time processing system developed by Tohoku University in the Sichuan Telemetered Seismic Network would help to improve the location accuracy of events beneath the network.

Usefulness of dynamic contrast-enhanced MR imaging in the evaluation of pulmonary isolated lesions

Objective： The aim of our study was to investigate the value of dynamic contrast-enhanced MRI for evaluating differential diagnosis of pulmonary isolated lesions. Methods： Twenty-nine consecutive patients enrolled in this study, all of whom underwent DCE-MRI examinations and received a histologic and clinical diagnosis. Among these, lung tuberculoma 7 cases, harmatoma 3 cases, peripheral lung cancer 19 cases. DCE-MRI was acquired with 3D LAVA technique, total 18 phases were acquired, scanner time of per phase was 5-7″. After contrasting agent, twice successive scanning was acquired at 10″ and 50″. Then 1′30″, 2′, 2′30″, 3′, 3′30″, 4′, 5′, 6′, 7′, 8′, 9′, 10′, 11′, 12′ performed scanning. Region of interest was placed on the Maximum level in the tumors. According to Schaefer＇s standard, four types of time signal intensity curve （TIC） were classified, which were A, B, C and D. Compared the dynamic parameters between benign and malignant nodules. Results： Lung tuberculoma may display three curves： A type 1 case, ring-shaped enhancement 4 cases （periphery ring A type, central region D type）, D type 2 cases. Harmatoma may display three curves： A type 1 case, C type 2 case. Peripheral lung cancer may display A type. Except 2 cases D type lung tuberculoma, we compared curve data of 8 cases benign nodules （including tuberculoma Atype and periphery ring Atype, harmatoma Atype and C type） and lung cancer. SlEP%： benign nodules 0.7885 ±0.5543, lung cancer 1.2623 ±0.3059, P 〈 0.05; MER： benign nodules 1.0007 ± 0.4251, lung cancer 1.3694 ±0.2740, P 〈 0.05; washout： P 〉 0.05. Conclusion： Lung MR imaging is helpful to diagnosis and differential diagnosis of isolated benign and malignant nodules. SIEP% and MER could offer valuable information. The evolution of global tuberculosis may be from A type to ring-shaped ennoblement to D type. It was easy to do right diagnosis to lung tuberculoma with ring-shaped ennoblement and D type. Peripheral lung cancer commonly displayed A type and needed identification with acute inflammation. So, it is important to anti-inflammatory follow-up for a few A type nodules.

Mammography combined with breast dynamic contrast-enhanced-magnetic resonance imaging for the diagnosis of early breast cancer

Objective The aim of this study was to investigate the application of mammography combined with breast dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) for the diagnosis of early breast cancer. Methods Mammography and DCE-MRI were performed for 120 patients with breast cancer(malignant, 102; benign; 18). Results The sensitivity of mammography for early diagnosis of breast cancer was 66.67%, specificity was 77.78%, and accuracy was 68.33%. The sensitivity of MRI for early diagnosis of breast cancer was 94.12%, specificity was 88.89%, and accuracy was 93.33%. However, the sensitivity of mammography combined with DCE-MRI volume imaging with enhanced water signal(VIEWS) scanning for early diagnosis of breast cancer was 97.06%, specificity was 94.44%, and accuracy was 96.67%. Conclusion Mammography combined with DCE-MRI increased the sensitivity, specificity, and accuracy of diagnosing early breast cancer.

Preliminary study on characteristics of earthquake precursor of earth resistivity anisotropy degree in East China

Introduction The degree of earth-resistivity anisotropy was described (MAO, et al, 1995, 1998) as follows: S=|1\nn∑I=1(ρSN\ρEW)I|-1|×103 n=6(1) whereρNS and ρEW are monthly mean values of earth resistivity in the direction of NS and EW, respectively, S is the half-year value. Equation (1) shows that if ρNS=ρEW, then S =0 and the electrical property of medium is isotropic; if ρNS≠ρEW, then S≠0 and the electrical property of medium is anisotropic. When S increases, the anisotropy of electrical property of medium is enhanced. Because the rightside of equation (1) is absolute value and the possibility ofρNS＞ρEW and ρNS＜ρEW can be different at different stations, the increase or decrease of S cannot reflect the relative changes between ρNS and ρEW. FENG, et al (2000) defined S as follows:……

Rollback reconstruction for TDC enhanced perfusion imaging

Tomographic perfusion imaging is a significant imaging modality for stroke diagnosis.However,the low rotational speed of the C-arm(6–8 s per circle)is a challenge for applying perfusion imaging in C-arm cone beam computed tomography(CBCT).Traditional reconstruction methods cannot remove the artifacts caused by the slow rotational speed or acquire enough sample points to restore the time density curve(TDC).This paper presents a dynamic rollback reconstruction method for CBCT.The proposed method can improve the temporal resolution by increasing the sample points used for calculating the TDC.Combined with existing techniques,the algorithm allows slow-rotating scanners to be used for perfusion imaging purposes.In the experiments,the proposed method was compared with other dynamic reconstruction algorithms based on standard reconstruction and the temporal interpolation approach.The presented algorithm could improve the temporal resolution without increasing the X-ray exposure time or contrast agent.

Pharmacokinetic comparison between ultraselection of uterine artery and peripheral vein chemotherapy of carboplatin in cervical cancer

Objective:The present study is to compare pharmacokinetics difference of carboplatin by using ultraselection uterine artery with by using peripheral vein in cervical cancer.Methods:Thirteen patients with locally advanced cervical cancer who had been proved by pathobiology were randomly divided into two groups:the ultraselection uterine artery group(group A, n = 6) and the peripheral vein(group B, n = 7).Carboplatin was administered by infusing into artery or vein in both groups at the dosage of 300 mg/m2.Tissues from the cervical tumor were collected at different times after infusion in both groups and then analyzed.Results:The peak concentration of platinum in tumor tissue was about 2.79 times higher in group A than that of group B(P < 0.05).The platinum concentrations in tumor in group A reached its peak levels immediately after infusion.But, group B had delayed time.While, for the time point of 0 min, when the administration finished immediately, the platinum concentration in tumor was significantly higher when compared with group B(P < 0.05).The tumor tissue area under the concentration(AUC) of carboplatin was about 2 times higher in group A than that of group B(P < 0.05).Conclusion:We observed the pharmacological advantages of chemotherapy by using ultraselection uterine artery administration of chemotherapeutic agent carboplatin in tumor tissue which provided theoretical basis and laboratory parameters of the intra-arterial chemotherapy for gynecologic malignancy.

Outboard abnormal noise source localization method with curved surface projection based on time delay matching and weighting criterion

An improved localization method consisting of ＂filtering-time delay estimationhyperbolic localization＂ is proposed. Combining the empirical mode decomposition（EMD）and time delay estimation method based on generalized average magnitude difference function,the original signals are decomposed into intrinsic mode function（IMF） components. The energy distribution criterion and spectrum consistency criterion are used to select the IMFs, which can represent the physical characteristics of the source signal. Several sets of signals are applied to estimate the time delay, and then a vector matching criterion is proposed to select the correct time delay estimation. Considering the hydrophones location, a shell model is established and projected to a plane according to the quadrant before the hyperbolic localization. Results of mooring and sailing tests show that the proposed method improves the localization accuracy,and reduces the error caused by time delay estimation.

Physical and numerical investigation on fluid flow and inclusion removal behavior in a single-strand tundish

Aiming at the problem that the existence of inclusions in the tundish continuous casting process can easily lead to quality defects of the slab,the stainless steel continuous casting tundish was taken as the research object.The effects of flow control device,inclusion density and inclusion size on the mixing characteristics of molten steel and inclusion behavior in tundish were studied.The results showed that compared with the tundish without flow control device,the average residence time of molten steel was prolonged by about 49 s,the dead zone volume fraction was reduced by 8.93%,and the piston fluid integral rate was increased by 12.68%.In the turbulence inhibitor(TI)tundish with weir-dam combination,the removal rate of inclusions with a density of 2700 kg m^(-3) and a particle size of 5 lm is 63.32%,while the removal rate of large inclusions with a density of 150μm could reach 89.04%.When the inclusion particle size was 10-50μm and the density was 2700-4500 kg m^(-3),the effect of inclusion density on inclusion removal rate was small.At the same time,when weir-dam combination TI tundish was set,the inclusions were mainly limited to the slag-metal interface of the first and second chambers of the tundish.The removal rate of inclusions in the first chamber was generally improved,with 10μm inclusions accounting for 47.67% and 150μm inclusions accounting for 60.69%.Furthermore,it has the best effect on the removal of small-size inclusions,especially those less than 70μm.

Influence of non-iso-velocity casting on flow-field index of a 41-ton six-strand Tundish by physical and numerical modeling

The flow-field index in a 41-ton six-strand tundish is considered through adjusting the ratio of the casting velocity between the strands to eliminate the negative impact of iso-velocity casting in multi-strand tundish on the consistency of each strand due to the large ratio of length to width with narrow shape structure,resulting in poor consistency of each strand.In particular,the response time of strand-1 and strand-6 is relatively long,which affects the uniformity of the temperature field and flow field of the entire tundish.On the basis of verifying that the error between the numerical simulations and hydraulic experiments is less than 6%,six cases with the casting velocity ratio changing from 0.8 to 1.3(with an interval of 0.1)are considered by calculation of numerical models.It is concluded that the consistency of each flow can be obviously improved by increasing the casting velocity ratio between side-strand and middle-strand.With increasing the casting velocity ratio,the flow field in the tundish became much active,the temperature field presented well uniformity,and the tracer concentration distribution in local dead zones was improved.