Objective To study the application value of direct digital X‐ray radiography system in the degenerative lumbar insta‐bility .Methods 100 patients with degenerative lumbar instability disease were collected in our hospital ,in which there were L4 ,L5 (80 cases) and L5 ,S1 (20 cases) with degenerative lumbar instability disease .Carestream DRX‐Evolution system was used ,which included conventional horizontal lumbar function photography (control group) and physiological load of lumbar function photography (observation group) .Changes of the displacement or the angle of the lumbar segment on two groups were measured ,and the statisti‐cal software was used to carry on the comparative analysis .Results In 100 patients ,the position and the physiological load position were showed on the sagittal position which were as following :For the lumbar segment of L4 and L5 ,flexion [position (4 .50 ± 0 .25) mm , load position (4 .78 ± 0 .30) mm] ,extension [position (4 .87 ± 0 .22) mm ,load position (5 .18 ± 0 .30) mm] ,and for the lumbar segment of L5 and S1 ,flexion [position (4 .64 ± 0 .24) mm ,load position (4 .91 ± 0 .24) mm] ,extension [position (4 .95 ± 0 .30) mm , load position (5 .30 ± 0 .29) mm];For the intervertebral angle degree of L4 and L5 ,flexion (position 10 .64° ± 0 .29° ,load position 12 .12°± 0 .57°) ,extension (position 11 .57°± 0 .24° ,load position 12 .61°± 0 .28°);For the intervertebral angle degree of L5 and S1 , flexion (position 11 .63° ± 0 .26° ,load position 12 .72° ± 0 .27°) ,extension (position 13 .55° ± 0 .30° ,load position 14 .58° ± 0 .33°) , respectively .The difference between two groups was statistically significant (P< 0 .05) .Conclusion Compared with traditional method ,DR lumbar physiological weight‐bearing functional can more accurately understand the lumbar instability degree ,grading and lumbar positive rate ,which provides the basis for clinical diagnosis and treatment plan .

Objective To investigate the cyclical changes of the apparent diffusion coefficient (ADC) values of the normal uterine zonal structures and explore physiological mechanism and clinical significance of the changes .Methods Nineteen healthy young fe‐male volunteers were selected to receive DWI (b=0 and 1 000 s/mm2 ) scan during periovulatory ,late secretory and menstrual pha‐ses .The ADC values of endometrium ,junctional zone and myometrium were measured and the differences of the ADC values were analyzed .Results The ADC values among three structures were significantly different in three phases (P< 0 .05) .The ADC value of myometrium was highest and the second was endometrium and the last was junctional zone .The differences of specific uterine zonal structures in different phases were statistically significant (F=55 .674 ,P<0 .05) .There was a interaction effect between menstrual cycle and uterine structures .Conclusion The effect of zones and different phases of the menstrual cycle in young women on ADC val‐ues of uterine structures should be considered when use ADC values to diagnose uterine diseases .

Objective To evaluate the diagnostic value of MRI for the mammographic sign of focal asymmetry of the breast (FAB) .Methods The morphological features of MRI and Time‐signal intensity curve (TIC) types of 46 cases of mammographic signs of FAB were analyzed retrospectively .Results In all 46 patients ,MRI detected 46 lesions in the corresponding areas of FAB on mammography ,in which 35 cases of benign lesions and 11 cases of malignant lesions were confirmed by pathology .The accuracy , positive predictive value and negative predictive value of the sub‐leaf shape and edge burr of the breast lesions were 82 .61% ,66 .67% , 86 .49% and 86 .96% ,85 .71% ,87 .18% respectively .TIC showed:in type Ⅰ ,all 17 cases were benign;In type Ⅱ ,4 cases were be‐nign and 2 cases were malignant ;In type Ⅲ ,9 cases were all malignant .The diagnostic accuracy of MRI for the benign and malignant breast lesions was 86 .96% .The positive predictive value and negative predictive values were 81 .82% and 96 .88% respectively .Con‐clusion MRI can definitely estimate the potential character of lesion in FAB ,and more accurately discriminate malignant and benign breast lesions .

Objective To investigate the atypical CT ,MRI findings of pancreatic neuroendocrine tumors (PanNETs) ,in order to improve diagnosis .Methods The clinical ,imaging and pathological data of 6 patients with PanNETs confirmed by pathology were analyzed retrospectively .Results In all 6 cases ,2 lesions were located in the pancreatic head ,3 lesions in the pancreatic body ,and 1 lesion in the pancreatic tail .There were 2 functional PanNETs with an average size of 2 .1 cm × 2 .6 cm ,which showed homogeneous density or signal .There were 4 nonfunctional PanNETs with an average size of 2 .7 cm × 4 .3 cm ,one of which had calcification ,and two of which had obviously cystic change ,including intracapsular bleeding in one case .Contrast‐enhanced examinations showed that all 6 lesions had mild or moderate enhancement .Three lesions were manifested as relatively intense enhancement in the arterial and portal venous phase ,but decreased enhancement in the delayed phase ,including annular envelope enhancement in one case .Two le‐sions were manifested as progressive enhancement .The last case was manifested as inwardly filled enhancement .Three lesions had unclear boundaries ,while one lesion had splenic vein invasion .Two cases accompanied with mild expansion of the common bile duct or pancreatic duct .Conclusion PanNETs can be ma+nifested as atypical findings such as obviously cystic changes ,and(or) mild to moderate enhancement .It is suggested that the atypical imaging findings of PanNETs should be recognized well to improve the diag‐nostic accuracy .

Objective To investigate the changes of gamma-aminobutyric acid (GABA) in the anterior cingulate cortex of perimenopausal women with depression.Methods Forty perimenopausal women as the experimental group and ten healthy women as the control group were recruited and followed up for 18 to 24 months.The proton magnetic resonance spectroscopy (1H-MRS) was used to acquire the concentrations of GABA in the anterior cingulate cortex.The experimental group was examined before and after menopause.The control group was examined before into the group and after out of the group.The experimental group after menopause was further divided into the anxiety group and the depression group according to the Classification and Diagnostic Criteria of Mental Disorders in China-Third Edition (CCMD-3), 14-item Hamilton Anxiety Scale (HAMA-14) and 17-item Hamilton Depression Scale (HAMD-17).The data of three groups were compared respectively.Results The results showed that the concentrations of GABA after menopause in both of the anxiety group and depression group were significantly lower (P<0.05) than those before menopause, and were also significantly lower (P<0.05) than those in the control group.The concentrations of GABA after menopause in the depression group were significantly lower(P<0.05) than those in the anxiety group.Conclusion The changes of GABA in the anterior cingulate cortex are related with the pathophysiology mechanism of perimenopausal depression and the symptoms of perimenopausal depression.

Objective To evaluate the ability of ultra-high-b-value diffusion weighted imaging (DWI) in diagnosis of the prostate cancer (PCa) at 1.5T MR.Methods 12 patients with PCa and 17 patients with benign prostate hyperplasia (BPH) proved by histopathology underwent MRI and DWI examinations (b=400, 800,1 400 s/mm2).The signal intensity and visual degree of region of interest (ROI) in all DWI with different b values were respectively measured.The signal intensity and visual degree of ROI between high-b-value DWI and ultra-high-b-value DWI were compared,respectively.Results The difference of signal intensity of PCa between high-b-value DWI and ultra-high-b-value DWI was statistically significant (χ2=220.957,P=0.000<0.05).The signal intensity of PCa was getting brighter in DWI with higher b value.The difference of visual degree between these two groups was also statistically significant (χ2=11.378,P=0.003<0.05).The difference among PCa, BPH and normal prostate peripheral zone was statistically significant in ultra-high-b-value DWI (χ2=25.913, P=0.000<0.05).The brightness of PCa in ultra-high-b-value DWI mainly was bright or grey-bright (71.4%), while the brightness of BPH and normal prostate peripheral zone were mainly dark or grey-dark (BPH 63.0%, normal prostate peripheral zone 73.3%).The difference of visual degree among PCa, BPH and normal prostate peripheral zone was statistically significant difference as well (Z=-6.908,-6.110,P=0.000<0.017).The diagnostic efficiency of the signal intensity and visual degree were highest with b=1 400 s/mm2.Conclusion DWI with ultra-high-b-value can improve the display rate of the PCa at 1.5T MR, making easier the detection and diagnosis of PCa.

Objective To investigate the feasibility of using CT texture analysis to differentiate among lipid-poor adrenal adenoma,pheochromocytoma and adrenal metastases.Methods 66 lipid-poor adrenal adenoma,98 pheochromocytoma and 101 adrenal metastases lesions were analyzed retrospectively.All the patients had abdominal non-enhanced CT and adrenal enhanced CT scans.We used TexRAD software to analyze the textural features of CT images and compared the differences in each texture parameter among three adrenal lesions.Results On non-enhanced CT images,there were significant differences in Mean and Kurtosis at all the texture scales(SSF 0-6) among the three types of adrenal lesions (P<0.05),as well as SD at fine and coarse texture scale (SSF 2,6)(P<0.05).Entropy (SSF 0-3, 5-6) and MPP (SSF 0-2, 4-6) were significantly lower in lipid-poor adrenal adenoma and adrenal metastases than that in pheochromocytoma (P<0.05).There were significant differences in Skewness (SSF 0-3) among three types of lesions, which was lowest in pheochromocytoma and highest in adrenal metastases.On enhanced CT images, Mean, SD, Entrophy and MPP showed significantly differences among the three types of adrenal lesions at all the texture scales (SSF 0-6) (P<0.05), which were all highest in pheochromocytoma and lowest in adrenal metastases.Skewness (SSF 0) and Kurtosis (SSF 0, 2) were significantly lower in adrenal metastases than that in lipid-poor adrenal adenoma and pheochromocytoma (P<0.05).Conclusion There are significant differences in CT texture analysis parameters among lipid-poor adrenal adenoma,pheochromocytoma and adrenal metastases.CT texture analysis has potential clinical application values in differentiating these three adrenal lesions.

Objective To investigate the value of advanced virtual monoenergetic technique(mono-plus) of dual-energy CT (DECT) in improving imaging quality of the lliofemoral arteries.Methods Forty consecutive patients underwent DECT scan.Mono-plus images (40 keV),optimal monoenergy images and mixed energy images were obtained by using Siemens Syngo.via VB10A workstation.CT values,signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and subjective image quality were calculated in the abdominal aorta,iliac artery,external iliac artery,femoral artery,profound femoral artery, lateral circumflex femoral artery,transversal branch of lateral circumflex femoral artery,medial circumflex femoral artery and profound branch of medial circumflex femoral artery and compared among the three groups.Results Compared with the optimal monoenergy and mixed energy groups,CT value and CNR of the 9 arteries were significantly higher in the mono-plus group (P<0.003).SNR of the transversal branch of lateral circumflex femoral artery and the profound branch of medial circumflex femoral artery showed no significant difference (P>0.05) among the threegroups,whereas SNR of the arties bigger than the 6th grade branch were significantly lower in the mono-plus group (P<0.05).The subjective image quality in the mono-plus group was significant better than the other two groups(P<0.001).Conclusion 40 keV mono-plus technique in DECT can improve the display of lliofemoral arteries especially the small and distal branches.

Objective To evaluate the imaging features and causes of cerebral cortical laminar necrosis(CLN) in children,to improve understanding this sign.Methods The imaging and clinical data of 33 children diagnosed with CLN were analyzed retrospectively.The imaging features of CT and MRI were summarized and compared according to their etiologies.Results Children cerebral CLN involved multiple lobes of bilateral hemicerebrum, including the cortical region, subcortical region and basal ganglia region, and linear or gyral shape,patchy shape and punctate shape abnormal density or signal were demonstrated.The typical imaging features were high-signal intensity over the lateral cortical surfaces or along the gyri on T1WI and FLAIR.Diffusion weighted imaging(DWI) showed high signal with restricted diffusion on acute-stage, and Gd-DTPA enhancement demonstrated linear or gyrate enhanced appearance on early-stage.The extent of CLN of cerebral infarction was relatively limited.Acute anoxic encephalopathy showed an early imaging change and extensive involvement.While chronic anoxic encephalopathy and inflammatory encephalopathy showed a late imaging change and a longer existence.Conclusion Children cerebral CLN may have various causes and imaging features,and show characteristic chronological signal changes on imaging studies.The different causes result in the different patterns for CLN in distribution and time distribution.

Objective To evaluate the effect of CT temporal subtraction(TS) for detection of lung nodules.Methods 80 cases of CT images (current and previous CT images) and corresponding CT TS images were presented, which included 30 cases with nodules(75 nodules) and 50 controls.4 observers, including 2 radiologists and 2 residents, indicated their confidence level regarding the presence of a new emerging or larger or solid component than before,which first used standard CT images, then with the addition of CT TS images.Receiver operating characteristic(ROC) curve analysis was used to evaluate the observers'' performance.Results The mean value of the area under the ROC curve (AUC) were 0.860 and 0.925 for four observers without and with TS images,respectively(P<0.01).Average sensitivity for detection of lung nodules was improved from 77.3%(58/75) to 89.3%(67/75) by using CT TS images.Conclusion The use of CT TS images can significantly improve radiologists'' performance for detection of lung nodules,especially when a small size solid or subsolid nodule presents near the pulmonary hilum.CT TS is more helpful for residents.