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Objective To investigate the value of early?phase enhancement ratio combined with peripheral vascular diameter in the differential diagnosis of benign and malignant breast lesions using 3.0 T dynamic contrast?enhanced magnetic resonance imaging (DCE?MRI). Methods Sixty seven cases of patients (35 with malignant lesions and 32 with benign lesions in the breasts) were retrospectively analyzed. Their diagnoses were confirmed by surgery and pathology and all the patients underwent breast MRI plain scan and DCE?MRI in the two weeks before surgery. Lesion ROIs were drawn and time?signal intensity curves in the DCE?MRI were generated. Early?phase enhancement rate, time to peak, early?phase enhancement ratio, numbers of tumor vessel within 3 cm of the lesion and diameter of the largest vessel were recorded. Mann?Whitney U test was used to compare the difference of DCE?MRI between benign and malignant lesions, and the ROC curve was used to evaluate the efficiency of early?phase enhancement rate, early?phase enhancement ratio and vascular diameter in differentiating benign and malignant lesions. Results With breast malignant lesions, the medians of time to peak, early?phase enhancement rate, early?phase enhancement ratio, numbers of tumor vessel and vascular diameter were 2.2 s, 176.0%, 100.0%, 4 and 2.96 mm respectively, while with benign lesions of these parameters were 4.7 s, 113.3%, 81.9%, 0 and 0.00 mm respectively, and the differences were statistically significant (all P<0.05).When early?phase enhancement rate was used for differential diagnosis of breast benign and malignant lesions, the area under the ROC curve was 0.702 and the sensitivity and specificity were 82.86%and 56.25%with a threshold of 120.0%. When early?phase enhancement ratio was used, the area under the ROC curve was 0.854 and the sensitivity and specificity were 94.29% and 68.75% with a threshold of 86.0%. When peripheral vascular diameter was used, the area under the ROC curve was 0.896 and the sensitivity and specificity were 74.29%and 84.38% with a threshold of 2.78 mm. When early?phase enhancement ratio was combined with peripheral vascular diameter, the area was 0.925 and the sensitivity and specificity were 97.14% and 62.50%. Conclusion In the differential diagnosis of benign and malignant breast lesions under DCE?MRI, early?phase enhancement ratio combining with peripheral vascular diameter has improved sensitivity.
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Objective To evaluate the diagnostic ability of fusion images of SWI and DWI in ischemic penumbra(IP)of patients with acute ischemic stroke(AIS).Methods 47 AIS patients were retrospective analyzed.Two neuroradiologists analyzed the fusion images of SWI and DWI respectively.SDM was defined as that the hypo-intensity signals of intramedullary or sulcal veins were dilated or increased on fusion images compared with contralateral areas.The results compared with the PDM,which was considered as the“gold standard”.Areas under the receiver operating characteristic curve(AUC)were used to assess the efficacy of SDM which determined by fusion images and compared to PDM.Chi-square test was used to analyze the consistency between the two neuroradiologists and also the consistency between SDM and PDM in IP assessment Results The fusion images of SWI and DWI had a high diagnostic efficacy compared to PDM, AUC of the two radiologists were 0.885,0.877,the diagnostic sensitivity were 84.2%,78.9% and specificity were 92.9%,96.4%respectively.There was also a high consistency in SDM assessment through fusion images between the two neuroradiologists (Kappa=0.908,P >0.05). Conclusion Fusion images of SWI and DWI have a high diagnostic efficacy in IP assessment,which may be considered as a simple approach for IP assessment in patients with AIS.
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Objective To optimize the parameters for the diffusion tensor imaging (DTI)of the ulnar nerve in elbow.Methods 5 groups of DTI sequences with different b values and numbers of diffusion gradient directions (NDGDs)were used to collect ulnar nerve images from 13 volunteers,and then the diffusion tensor tractography (DTT)was established.The fractional anisotropy (FA),apparent diffusion coefficient (ADC),length of ulnar nerve fiber and DTI image quality were compared under different imaging parameters. Results DTI results for 18 normal ulnar nerves were included in the study.Under different imaging conditions,FAs showed no significant differences.With constant NDGDs,increasing b value decreased both image quality and ADCs of the ulnar nerve.NDGDs had no significant effects on ADCs or image quality.When b=1 000 s/mm2 and NDGDs=20,the length of the ulnar nerve fiber was the longest and DTT had the best subjective scoring in image quality.Conclusion b=1 000 s/mm2 and NDGDs=20 is recommended for DTI of elbow ulnar nerve,so as to obtain high image quality and stable observing targets.
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Objective To evaluate the diagnostic value of intra-arterial thrombi under went susceptibility weighted imaging(SWI) in patients with acute ischemic stroke(AIS).Methods The MRI images of 133 patients with AIS was analyzed,included time of flight MR angiography(TOF-MRA )and SWI.The patients were divided into two groups according to the time between onset of symptoms and MR imaging (group A,interval time<24 h;group B,interval time 24-72 h).Two neuroradiologists who were blin-ded to the patients clinical information,documented the number and location of susceptibility vessel sign (SVS)in SWI and embolic occlusion or stenosis on TOF-MRA in AIS patients.Results The thrombus detection rate in group A was higher than that in group B.There was no significant difference in the overall detection rate of thrombi between SWI and TOF-MRA in all AIS patients,but the thrombi detection rate in M3 segement of middle cerebral artery(MCA)with SWI was higher than that with TOF-MRA in group A(P <0.05).Conclusion SWI performs a high diagnostic value for thrombus detection in AIS patients,especially for the thrombus detection of M3 segement in early period of AIS.
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Objective To discuss the MRI features and its clinical significance of bone contusion in knee joint.Methods MR images of injuries of knee in 40 cases were retrospectively analyzed,the complications were reviewed simultaneously.Results 69 lesions of bone contusion in 40 cases were discovered,of them,Ⅰ type was in 38 and Ⅱ type was in 31, in company with fractures were 24 in 22 cases and ligament injury was in 33 cases.Conclusion The present of bone contusion is prompt to the bone injuries,MRI is of significant value in showing bone contusion and its complications in knee.