Diagnostic values of normalized ADC value in benign and malignant breast lesions / 实用放射学杂志

Objective To evaluate the values of DWI normalized ADC value in breast MRI in the differential diagnosis of benign and malignant breast lesions.Methods The absolute value of ADC,normalized ADC value and T1 WI dynamic contrast-enhanced TIC were analyzed in 49 patients with benign and malignant breast lesions;the efficiencies of single method diagnosis and combined diagnosis were assessed.Results When b=1 000 s/mm2 ,the absolute value of ADC <1.25×10 -3 mm2/s was taken as the thresh-old value for the diagnosis of malignant breast lesions,the area under the ROC curve was 0.818,the sensitivity was 73.9% and the specificity was 84.6%;the normalized ADC value <0.55 × 10 -3 mm2/s was taken as the diagnostic threshold,the area under the ROC curve was 0.901,the sensitivity was 87.0% and the specificity was 88.5%,there was a significant difference between both values.The lesions with a wash-out type of T1 WI dynamic contrast-enhanced TIC were diagnosed as malignant lesions,the sensitivi-ty was 89.5% and the specificity was 70.0%.The absolute value of ADC and T1 WI dynamic contrast-enhanced TIC were applied combinedly,the predicted percentage correct was 81.6% for the diagnosis of breast lesions,while the normalized ADC value and T1 WI dynamic contrast-enhanced TIC were applied combinedly,the predicted percentage correct was increased,which was 89.8%. Conclusion Normalized ADC value has a higher sensitivity and specificity in differentiating benign and malignant breast lesions,its combined application with T1 WI dynamic contrast-enhanced TIC can improve the diagnostic performance of breast lesions.

Clinical application of pancreatic diffusion-weighed imaging at 3T / 中华胰腺病杂志

Objective To investigate the feasibility of pancreatic DWI at a 3T MR imager and its value for the qualitative diagnosis of pancreatic tumors. Methods For 20 normal healthy volunteers and 47 patients with pancreatic tumors [21 pancreatic carcinoma (PC), 7 mass-forming chronic pancreatitis (MFCP)and 19 cystic lesions), routine pancreatic MRI and pancreatic DWI using b values (500 and 1000 mm2/s)were obtained, the DWI signal intensity (SI) and apparent diffusion coefficient (ADC) value of pancreatic lesions and adjacent tissue was measured. Results In the b = 500 and 1000 mm2/s DWI images, there was no significant difference in ADC value between different parts of normal pancreas. But PC and MFCP were shown as hyperintensity mass, in addition, the related SI1000 of PC at b = 1000 mm2/s DWI was significantly higher than that of MFCP (1.238 +0.448 vs. 0.371 +0.293, P＜0. 01). Compared with normal pancreas,beth PC and MFCP presented as decreased ADC500 and ADC1000 value. The ADC1000 of PC was significantly lower than that of MFCP [ ( 1. 087 + 0. 175 ) mm2/s vs. ( 1. 279 ± 0.213 ) mm2/s]. Pancreatic cystic lesions were shown as hyperintensity in DWI at b = 500 mm2/s, but were depicted as iso-intense signal or low-signal lesions in DWI using b = 1000 mm2/s. Both ADC500 and ADC1000 of pancreatic cystic lesions were higher than that of normal pancreas. Conclusions 3T-MR DWI is helpful to differentiate pancreatic lesions. High b value DWI is more valuable for the qualitative diagnosis of pancreatic mass.

Diffusion tensor imaging study of Parkinson disease / 中国医学影像技术

Objective To investigate the change of diffusion tensor imaging (DTI) parameters on extracorticospinal tract and some domain in Parkinson disease (PD), and to explore the relationship between DTI parameters and PD. Methods Ten PD patients with unilateral symptoms and 20 with bilateral symptoms were enrolled in PD group 1 and PD group 2, respectively. Control group included 30 volunteers whose age and sex matched with those of PD group. PD patients and the subjects in control group underwent routine MR plain scan and DTI scan. FA and ADC maps were obtained after postprocessing. FA values and ADC values of ROI (region of interest) were measured. ROI included substantia nigra (SN), red nucleus (NR), globus pallidus (GP), putamen (PUT), caudate nucleus (CN), thalamus, genu of corpus callosum, splenium of corpus callosum, callosal gyrus, white matter of frontal lobe and anterior centra gyrus. All data were analyzed statistically. Results FA value of SN, CN, thalamus and splenium of corpus callosum of PD group degraded obviously compared with that of control group (P<0.05). FA value of PD group 1 was lower than control group and PD group 2 at anterior central gyrus and callosal gyrus (P<0.05). There was no significant difference of FA value among PD groups and control group at other ROI's. There was negative correlation between the changes of FA value at SN and PD grade. No significant difference was found in ADC value among PD group 1, PD group 2 and control group, but there was an increasing tendency of ADC value along with the progress of PD. Conclusion FA values of SN, CN, thalamus and splenium of corpus callosum can offer some important information for the early diagnosis of PD. DTI is useful for the study about PD's pathomechanism and clinical manifestation in vivo.

Diffusion-weighted imaging in predicting and monitoring the response of uterine cervix cancer to concurrent chemoradiation / 中国医学影像技术

Objective To investigate the value of diffusion-weighted imaging (DWI) in predicting and monitoring the response of uterine cervix cancer to concurrent chemoradiation. Methods Seventeen patients with uterine cervix cancer underwent conventional MRI and DWI examinations before therapy and at one month and two months after the initiation of concurrent chemoradiation, and 8 of them underwent additional examinations at 15 d after therapy. The longest diameter of tumor before and after treatment was measured on axial T2WI. The mean ADC value among pre- and post-treatment of each group (CR, PR and SD) was compared. Results The mean ADC value before therapy of CR group was statistically lower than that of PR group (P＜0.05). There was negative correlation between mean pretreatment ADC value and percentage size reduction of tumor after concurrent chemoradiation at two months (r=-0.574, P＜0.05). The percentage ADC change of tumor at one month correlated positively with percentage size reduction of tumor at two months after concurrent chemoradiation (r=0.572, P＜0.05). Fifteen days after the initiation of concurrent chemoradiation, the mean ADC value of 8 patients increased significantly, however, the longest diameter of tumor showed no statistically significant changes compared with pre-treatment tumor diameter. Conclusion DWI has the ability to predict the response of uterine cervix cancer to concurrent chemoradiation, and it can monitor the treatment response as well.