Objective To explore the value of susceptibility-weighted imaging (SWI) for the assessment of chronic renal injury. Methods Thirty-nine patients with clinical diagnosis of chronic renal injury (RI group) who underwent routine renal MRI and SWI examination were retrospectively analyzed. They were divided into mild injured group (15 cases) and moderate to severe injured group (24 cases) by estimated glomerular filtration rate (eGFR). At the same time, 17 volunteers without chronic renal injury who had normal serum creatinine (Scr) and blood urea nitrogen were recruited as control group. All subjects underwent routine renal MRI and SWI examination. The ratios of cortex to medulla were measured and calculated in both kidneys' magnitude image and susceptibility weighted image, which were indicated as C/MMAG and C/MSWI. Independent sample t test was used to compare the differences of C/MMAG and C/MSWI between control group and RI group, and paired sample t test was used to compare the differences betweenC/MMAG and C/MSWI in each group. One-way ANOVA was used to compare the difference of C/MMAG and C/MSWI between the control group and the different RI groups. ROC was employed to assess the diagnostic efficacy of C/MMAG and C/MSWI in renal injury. Pearson linear correlation analysis was used to evaluate the correlation between C/MMAG, C/MSWI and eGFR, Scr in patients with renal injury. Results The C/MMAG and C/MSWI in the RI group were 1.101±0.039 and 1.071±0.046, respectively. C/MSWI was obviously lower than C/MMAG, and the difference was statistically significant (t=5.056, P<0.01). There was no significant difference between C/MMAG and C/MSWI in the control group (P>0.05). The C/MMAG and C/MSWI in the RI group were obviously lower than those in the control group, and the difference was statistically significant (t=4.564, 6.122;P<0.01).The C/MMAG and C/MSWI in the mild injured group and the moderate to severe injured group were significantly lower than those in the control group, the difference was statistically significant (P<0.05). While the differences of those between mild injured group and moderate to severe injured group showed no statistical significance (P>0.05). The area under ROC of C/MMAG and C/MSWI in diagnosis of renal injury were 0.853 and 0.952, respectively. C/MMAG was positively correlated with eGFR (r=0.460,P<0.01). Conclusions Susceptibility-weighted imaging can be used to assess chronic renal injury. Although it cannot reflect the degree of renal function damage, it has some value in the early diagnosis of mild renal injury.

Objective To value the capability of MRI in assessing invasiveness of intraductal papillary neoplasms of the bile duct(IPNB). Methods Thirty-nine patients with pathologically confirmed IPNB, who had upper abdominal MR examination within 6 weeks before complete resection of the tumor, were included in the retrospective study. Patients were divided into noninvasive and invasive groups pathologically. Eighteen cases were noninvasive and 21 were invasive. All had undergone MRI plain scans, MR cholangiopancreatography as well as contrast enhanced scans including arterial, portal and delayed phases. Tumor size, location, biliary dilation, thread signs, lesion morphology, lobe atrophy, cholelithiasis, biliary hemorrhage, vascular invasion and intraperitoneal lymphadenopathy were observed on MRI. ADC values and enhancement level of lesions were also measured. Between invasive and noninvasive groups, laboratory results, enhancement levels and ADC values were compared by t test or Mann-Whitney U test, and categorical variables like location and lesion morphology were compared by χ2 test. The diagnostic accuracy was calculated using receiver operating characteristic(ROC)curve analysis. Results No difference was found between invasive and noninvasive groups on gender, age, lesion morphology, bile duct diameter, location, existence of thread signs or cholelithiasis(P>0.05). While the differences on serum CA19-9 level, lesion size, ADC value, and lymph nodes/vascular invasion between groups reached statistical significance (P<0.05). Other than on plain scan(P>0.05), CNR and enhancement levels were also statistically different on arterial, portal and delayed phases between both groups(P<0.05). CA199, enhancement level and CNR of portal phase, as well as ADC value exhibited areas under the ROC curve(AUC)of 0.790, 0.891, 0.817 and 0.882 respectively in invasiveness judgment. Conclusion MR demonstrated relatively high value in assessing invasiveness of IPNB.

Objective To investigate the diagnostic value of texture analysis derived from conventional MR imaging in differentiating benign and malignant breast lesions. Methods Thirty-six patients with malignant breast lesion and 33 patients with benign breast lesion were retrospectively analyzed in our study. All patients underwent conventional MR imaging including axial T1WI, T2WI, and contrast-enhanced T1WI before surgery. Texture features were calculated from manually drawn ROIs by using MaZda software. The feature selection methods included mutual information (MI), Fishers coefficient, classification error probability combined with average correlation coefficients (POE + ACC) and the combination of the above three methods(FPM). These methods were used to identify the most significant texture features in discriminating benign breast lesion from malignant breast lesion. The statistical methods including raw data analysis (RDA), principal component analysis (PCA), linear discriminant analysis (LDA) and nonlinear discriminant analysis (NDA) were used to distinguish malignant breast lesion from benign breast lesion. The results were shown by misclassification rate. Results In the three kinds of sequences, the texture features for differentiating malignant breast lesion and benign breast lesion were mainly from T2WI which had the lowest misclassification rate 4.35%(3/69). The misclassification rates of the feature selection methods were similar in MI, Fisher coefficient and POE+ACC (15.94%to 56.52%for MI;17.39%to 56.52%for Fisher coefficient and 17.39%to 56.52%for POE+ACC). However, the misclassification rate of the combination of the three methods (4.35%to 53.62%for FPM) was lower than that of any other kind of method. In the statistical methods, NDA (4.35% to 27.54%) had lower misclassification rate than RDA (33.33% to 56.52%), PCA (33.33% to 53.62%) and LDA (15.94% to 44.93%). Conclusion Texture analysis of conventional MR imaging can provide reliably objective basis for differentiating benign from malignant breast lesions.

Objective To evaluate the role of the diffusion kurtosis imaging(DKI)in the differential diagnosis of breast lesions. Methods Seventy five breast lesions(32 benign and 43 malignant)in 72 patients confirmed by histopathology were studied. All patients underwent 3.0 T MR examinations, including T1WI, T2WI, T2WI-spectral adiabatic inversion recovery, 4b diffusion-weighted imaging, and dynamic contrast-enhanced MR imaging(DCE-MRI). Data were post-processed by mono-exponential and diffusion kurtosis models for quantitation of ADC, apparent diffusion for non-Gaussian distribution(D), and apparent kurtosis coefficient(K). All breast lesions were described with the classification by breast imaging report and data system(BI-RADS). Lesions with BI-RADS class 4B or above were rated as malignancy. Independent sample t test was used to compare the ADC, D, and K value differences between benign and malignant lesions . ROC analysis was performed to assess the role of ADC, D, K value, and BI-RADS in the differential diagnosis of breast lesions. The morphological characteristics, time-signal curve(TIC)type, and other differences between benign and malignant lesions were analyzed with Chi-square test. Results ADC and D values were significantly lower in malignant than in benign lesions(P<0.01). Conversely, K value was significantly higher in malignant lesions than in benign ones(P<0.01). The shape of the benign and malignant breast lesions, edge, enhancement mode, TIC, and BI-RADS classification difference had statistical significance(P<0.05, respectively). The areas under the ROC curve of ADC, D, K, DCE-MRI, and DCE-MRI combined with K value were 0.857, 0.884, 0.949, 0.806, and 0.958, respectively. DCE-MRI combined with K value had the highest diagnosis efficiency. At a cutoff value of K= 0.856, the sensitivity and specificity were 83.7% and 93.8%, respectively. Conclusions DKI model showed higher diagnostic efficiency than that of traditional DWI model. DCE-MRI combined with K value can increase the diagnostic efficiency in breast lesions.

Objective To evaluate the value of spectral CT imaging for the differential diagnosis of squamous cell carcinoma (SQCC) and adenocarcinoma (ADC) of the esophagogastric junction. Methods Forty-five patients with a mass in the esophagogastric junction proved by pathology underwent enhanced scan with spectral CT, including 20 cases of SQCC and 25 cases of ADC. Iodine concentration (IC) , water concentration (WC) , effective atomic number (Eff-Z) and spectral curve slope (λHU) of arterial phase (AP) and venous phase (VP) in the ROI of the mass were measured with gemstone spectral imaging post-processing software. The independent samples t test was used to compare the quantitative parameters above between two groups on the premise of satisfying normal distribution. ROC curves were drawn for the parameters which showed statistical differences and area under the curve (AUC) was used to measure and compare their respective differential diagnostic performance as well as the best threshold value. Results In AP,the average IC, Eff-Z, andλHU of ADC were (1.75±0.40) mg/ml, 8.65±0.22, and 3.33±0.74, respectively. The corresponding parameters of SQCC were (1.40 ± 0.35) mg/ml, 8.50 ± 0.20, and 2.71 ± 0.66, respectively. These parameters of ADC were significantly higher than that of SQCC (t=-2.833,-2.879,-2.678;P<0.05) . In VP, the average IC, Eff-Z, and λHU of ADC were (2.17 ± 0.23) mg/ml, 8.87 ± 0.11, and 4.10 ± 0.44, respectively. The corresponding parameters of SQCC were (1.67 ± 0.20) mg/ml, 8.60 ± 0.11, and 3.19 ± 0.41, respectively. The difference between ADC and SQCC was statistically significant (t=-6.963,-7.218,-6.521;P<0.05). For the average WC, No difference between the two groups in AP and VP was found. ROC curve analysis showed that IC, Eff-Z, andλHU in VP had better differential diagnostic performances than IC, Eff-Z, and λHU in AP, especially Eff-Z in VP. The AUC for it was 0.97. Using 8.72 as a threshold value, the sensitivity and specificity for diagnosis were 88.9% and 94.7% , respectively. Conclusion Multi-parameters quantitative analysis with spectral CT could be useful in the differential diagnosis of SQCC and ADC of the esophagogastric junction.

Objective To study the value of transfer constant(Ktrans)derived from dynamic contrast-enhanced MRI (DCE-MRI) for quantitative evaluation of Ki-67 labeling index (Ki-67 LI) in glioma. Methods Twenty patients with glioma who underwent DCE-MRI and operation were retrospectively reviewed. The Ktrans value and Ki-67 LI were acquired and correlated using the Spearman correlation test. Also, the Ktrans values were compared between high(larger than 10%)and low(no more than 10%)Ki-67 LI group with Mann-Whitney U test, receiver operating characteristic curves was performed to evaluate the diagnostic value. Results The Ktrans value(0.0165 to 0.8048, median 0.1252)was significantly associated with Ki-67 LI(5%to 50%, median 20%) (r=0.721,P<0.001), and the Ktrans value was significantly higher in high Ki-67 group(0.0810 to 0.8048, median 0.1810)than that in low Ki-67 LI group(0.0165 to 0.1456, median 0.0697)(Z=-3.209, P=0.001). The most predictive Ktrans value differentiated high Ki-67 LI and low Ki-67 LI with an area under the curve(AUC) of 0.945 at a sensitivity of 92.3% and specificity of 85.7%. Conclusion Ktrans value could be used for quantitative evaluation of Ki-67 LI in glioma.

Objective To investigate the character of aquaporin-1(AQP-1)expression in adrenal gland in diabetes mellitus and evaluate adrenal gland damage and function alterations by DWI with multiple b values. Methods Twenty male Sprague-Dawley rats were randomly selected by computer and randomized into 2 groups:untreated controls(n=10)and diabetes(DM)(n=10). Rats in diabetes group were fed with high-sucrose and high-fat diet, controls were fed with common diet. After fed with high-sucrose and high-fat diet for 4 weeks, rats in diabetes group were injected with streptozotocin(STZ). Forty days after diabetes induction with streptozotocin(STZ), MR imaging was performed in a 7.0 T scanner. Venous blood from the tails was collected before MRI scan to measure blood glucose, blood glucose more than 16.7 mmol/L wasregarded as diabetic status. All the rats underwent DWI with 18 b values(0 to 4500 s/mm2). Maps of pure diffusion coefficients(D), pseudo-diffusion coefficients(D*)and ultra-high ADC(ADCuh)were acquired. Rats were sacrificed after MRI scan for adrenal gland histopathology, AQP-1 immunohistochemistry analysis and AQP-1 optical density(OD)measurements. Student t test was used to compare the difference of D*, D, ADCuh and OD of AQP-1 between two groups. Results Eight diabetic animals developed hyperglycemia(two rats died during the modeling process). MRI scan was performed in all of the 18 rats. Signal intensity of D*map, D map and ADCuh map decreased gradually. ADCuh increased significantly in DM animals(0.24 ± 0.06) × 10-3mm2/s compared with control animals(0.18 ± 0.07) × 10-3 mm2/s(P<0.05), whereas there was no significant difference found between the two groups in their respective D*and D values(P>0.05). There was a noticeable increase in the AQP-1 labeling in the adrenal cell membrane and cytoplasm in DM animals compared with control animals. DM rats showed an increased OD value of AQP-1 in adrenal gland compared with the control animals(P<0.05). Conclusions We found significantly higher AQP-1 expression in adrenal gland in DM animals compared with controls. Ultra-high b-Values DWI may work as a useful way for noninvasive evaluation the change of adrenal function in DM.

Objective To evaluate the imaging characteristics of atypical teratoid/rhab doid tumor (AT/RT) of central nervous system(CNS), and to improve the diagnostic ability of the disease. Methods The clinical and imaging findings of 9 patients were retrospectively analyzed. There were 5 male and 4 female, ages 7 months to 5 years,median age was 1.4 years. MR enhancement studies were obtained in all the cases. One case had CT enhancement examination. Results The lesions were seen in brain in 8 cases and in lumbosacral spinal cord in one case. The tumors size varied from 4.8—7.8 cm, Necrosis was seen in nine cases, cystic change in eight cases and hemorrhage in five cases. The tumors had high signal on DWI, and low signal on ADC map. Dura matter invasion(2 cases), cerebrospinal fluid spread(2 cases)and intracerebral metastasis were seen. Conclusion There are some relatively specific imaging findings of primary CNS AT/RT that could assist their diagnosis.

Objective This retrospective study is to analyze and summarize the clinical features and therapeutic experience of the isolated abdominal aortic dissection(IAAD). Methods Totally 17 patients of IAAD, who were admitted to our hospital from January 2009 to January 2016, were included in this retrospective analysis. Five patients with obvious pain or abdominal aorta diameter of 30 mm accompanied with sub-renal anchorage area of 15 mm, underwent endovascular repair. In these 5 patients, 4 cases were subjected to bifurcated stent graft endovascular repair and 1 case received the aorta uni-iliac endovascular repair combined with femoral-femoral artery bypass treatment. Moreover, 2 patients with sub-renal anchorage area of less than 15 mm were subjected to surgical treatment. In these 2 patients, 1 case with obvious pain and abdominal aorta diameter of 30 mm underwent the abdominal aorta-right iliac artery bypass combined with femoral-femoral artery bypass, while the other case with abdominal aorta diameter of 30 mm but no pain received the abdominal aorta-bilateral iliac artery bypass. Furthermore, 8 patients with no obvious pain and abdominal aorta diameter of less than 30 mm received conservative medical treatment. In addition, there were 2 patients with obvious pain and abdominal aorta diameter of 30 mm suffering from sudden death during the surgical preparation. Important complications of these patients during hospitalization and follow-up period were recorded, analyzed, and compared. Results For the 5 patients undergoing endovascular repair, the averaged hospitalization duration was(15.4 ± 2.9)d, one of whom died during hospitalization. There were 3 cases with follow-up period of ≥ 12 months, and 1 case reported left iliac branch occlusion. For the 2 patients subjected to surgical treatment, the follow-up period was less than 12 months, and no serious complications occurred during hospitalization or follow-up period. For the 8 patients receiving conservative medical treatment, the averaged hospitalization duration was(11.1±5.2)d. There were 4 cases with follow-up period of ≥ 12 months, and no serious complications occurred during hospitalization or follow-up period. Conclusions Endo or open surgical treatment is recommended for patients with isolated abdominal aortic dissection with obvious pain or abdominal aortic diameter of 30 mm. For the patients with no pain and abdominal aortic diameter of less than 30 mm, conservative medical treatment is recommended.

Objective To study MRI features of fibroma of tendon sheath(FTS)and giant cell tumor of tendon sheath(GCTTS), so as to improve the diagnosis and differential diagnosis of two lesions. Methods Seventeen patients with FTS and 27 patients with GCTTS confirmed by operation and pathology were retrospectively analyzed. All patients were examined with MRI. The location, size, shape and the relationship with the surrounding tissue, the signal feature and enhancing pattern of the two groups were compared. Imaging features in the two groups were assessed and analyzed by using independent samples t test and Chi-square test. Results FTS were nodular or mass-like lesions(n=11). Few lesions appeared adjacent bone absorption(n=2). On T2WI, the lesions showed peripheral low signal ring(n=6)or internal mixed low-signal intensity of was striped or filamentous configurations(n=10). The volume of low-signal intensity accounted for more than 2/3 of the total lesion's volume(n=6). Enhanced T1WI, tumors revealed ring enhancement(n=6). GCTTS appeared mostly lobulated(n=16), common with adjacent bone compressive absorption(n=9). On T2WI, most of lesion had a peripheral low signal ring(n=22). Tumors revealed mixed high signals intensity with granular or patchy irregular low signal intensity scattered in the mass(n=17), the area of low signal accounts for less than 1/3 of total neoplastic volume(n=18). On contrast T1WI, GCTTS appeared heterogenous enhancement. Statistical analysis showed that the shape of the lesion, the presence or absence of compressive bone absorption, the presence of a low signal ring around the lesion, the shape of the Low-signal in T2WI and the proportion, and the presence of circumferential enhancement(P<0.01), there were statistically significant differences between the two. And there was no statistically significant difference in the age, gender and location of disease(P>0.05). Conclusion FTS and GCTTS has a different characteristic of MRI features. FTS were nodular or mass-like, T2WI signal was mixed low, the shape of the low-signal was striped or filamentous, accounting for more than 1/3 of total lesion's volume, enhanced T1WI, tumor shows ring enhancement;GCTTS appears mostly lobulated.Most of lesion has low signal ring, common with adjacent bone compress compressive absorption. T2WI, tumor reveals mixed high signals intensity with granular or patchy irregular low signal intensity scattered in the mass. The area of low signal accounts for less than 1/3 of total neoplastic volume.