Objective To study the clinical manifestat ions, MR diagnosis and differential diagnosis of sacral meningeal cyst.Methods 25 patients with sacral meningeal cyst proved by operation and pathology, 9 cases of male, 16 cases of female; the age ranged fro m 18 to 56 years old, average age is 40.3. All cases were performed on MR examin ation. Results The shape of cysts in 19 cases were elliptic,long marsupial shape in 3 cases,irregular in 1 case,string shap in 2 cases.The edge of cysts is clear and the wall of cysts is very thin.MR signal in tensity of fl uid in sacral meningeal cysts exhibits similarity to cerebrospinal fluid,which s hows uniform low signal in T 1WI and high signal in T 2WI.There are 8 cases sc an whose MR signal of cysts fluid is much higher than that of cerebrospinal flui d in T 2WI. In 7 cases thin strip nerve root can be found through the cysts in T 1WI and T 2WI. The antrast enhancement was made in 8 cases and there were no any enhancement both in content and wall of cyst.Conclusion MRI is one of the best examing methods for dia gnosiing of sacral meningeal cyst. Correct mastery of MR manifestations can not only help to give right dignosis, but also provide guidance for choices of clini cal treatment.

Objective To investigate the imaging appearances of esophageal tuberculosis.Methods 5 cases of esophageal tuberculosis proved by pathology were retrospectively analyzed.There were 2 male and 3 female patients aged between 24 and 36 years median age 29 years. All cases were undergone esophageal barium examination, CT scan and gastroscopy. The surgical resection of the tumor was complemented in one case.Results Esophageal barium contrast study showed: the location of lesions at upper, middle and low esophagus in 1,3 and 1 cases respectively. The X-ray features included filling defect in 2 cases, centripetal strictures in 2 cases, intraluminal barium patch in 1 case, extramural irregular fistulous formation in 1 case, mucosa destruction in 2 cases and mucosa flattened or disappeared in 3 cases. On chest CT, bronchiectasis in the posterior basal segment of left inferior lung in 1 case, enlargement of right hilum of lung and small nodule in the right chest wall in 1 case, irregular thickening in the wall of inferior oesophagus in 1 case, pleural adhesion in 1 case were showed, and the other two were normal. The accurate diagnosis was confirmed only in 2 patients preoperation.Conclusion Esophageal tuberculosis extent is not of imaging characteristics, its diagnosis should be in combination with clinical data.

Objective To investigate the imaging manifestations, clinical features and treatment of primary aggressive osteoblastoma (PAO)of the calcaneus.Methods The clinical data,imaging findings and treatment of PAO of the calcaneus in a young man retrospectively analyzed with literature review.The lesion was confirmed by pathology one and half years ago,and recurred after operation 10 months follow-up.Results X-ray and CT revealed expansive destruction of right calcaneus with little calcification or ossification,the bone destruction in the medial part of the calcaneus was obvious,the bone cortex was thin and incontinuous,there was no soft tissue mass or periosteal reaction.The talocalcaneal joint was not involved by the tumor.Neither other bones nor the root of Achilles' tendon showed direct tumor invasion or metastasis but neighboring swelling existed.Conclusion There are no significant differences about imaging manifestations, clinical features and laboratory analyses between primary aggressive and benign osteoblastoma of the calcaneus.The accurate diagnosis of PAO is only depending on pathology.The therapeutic effect with pure curettage and bone grafting for the lesion is not fine and tends to recur and malignant change.

Objective To evaluate the gray matter alterations in amyotrophic lateral sclerosis (ALS)by voxel-based morphometry (VBM),and further analyze the correlation between volume changes of gray matter and clinical characteristics.Methods Twenty-seven non-demented patients with ALS and 27 age and gender matched healthy controls were recruited.FSL-VBM was used to detect whole brain gray matter differences between the two groups.Seven prior ROIs were set to be analyzed,including bilateral precentral gyrus,postcentral gyrus,superior,medial,inferior,middle frontal gyrus,and insular cortex.The mean gray matter density of the ROIs was extracted in order to explore the correlation with several clinical measurements such as disease durations and disease severity scores,by using partial correlation analysis with age as covariates.Results Whole brain analysis showed significant gray matter loss in the left precentral gyrus,superior frontal gyrus and postcentral gyrus (numbers of voxel in clusters were 338,112,127,Z =4.83,4.09,6.42,P ＜0.05,FWE corrected).A prior seven ROIs analysis detected gray matter loss in the left precental gyrus,right precentral gyrus,left postcentral gyrus,superior frontal gyrus and left insular cortex (numbers of voxel in clusters were 1104,34,114,91,107,Z =5.87,3.71,4.26,6.29 and 3.51,P ＜0.05,FWE corrected).No statistical significant correlation between regional gray matter loss and clinical measurements were found.Conclusions Motor and extra-motor gray matter loss are present among patients with ALS,which demonstrates ALS as a multi-system disorder.In contrast to whole brain gray matter analysis,ROI analysis is more sensitive to detect extensive cortical changes.The heterogeneity of disease and sensitivity of method may contribute to the lack of correlation between gray matter volume decrease revealed by VBM and clinical characteristics.

Objective To select the proper enhanced methods of histogram egualization for the medical digital image. Methods By means of the full-frame histogram equalization(FFHE),local-area histogram equalization(LAHE) and adaptive-meighborhood histogram equalization(ANHE),medical digital images were enhanced,and the characteristics of these three methods were compared. Results Through the gray-level histogram equalization,the detail and the edge of medical digital images could be enhanced. Conclusion Toenhance the detail of local issue,it is better to use ANHE method.To enhance the edge of full image,which the full information must been taken into account,it is better to use FFHE method.

Objective To study feasibility of differentiation of benign and malignant by using eccentric rate of calcification in pulmonary spherical lesions.Methods Two hundred and forty cases with pulmonary spherical lesions(malignant in 170 and benign in 70) confirmed by pathology or clinical follow-up were collected in this study.All cases were underwent chest CT examinations.Nodule CAD software was used to demarcation of pulmonary spherical lesions and internal calcification.Calcification was defined as an area more than 3 pixel with calcification density(CT value＞120 HU).Furthermore,the ratio of calcification center distanceand calcification edge distance was calculated as Ecc.Mann-Whitney U test was used to compare the eccentric calcification rates between the malignant and the benign pulmonary spherical lesions.Taking pathological results as golden standard,the diagnostic efficacy of Ecc was analyzed using ROC curves.Results In 240 lesions,65 calcifications were detected,of which 18 were malignant calcification distributed in 10 lesions,and 47 were benign calcifications distributed in 16 lesions.The median of Ecc in benign and in malignant lesions were 0.80(0.28-1.29) and 3.01(1.52-4.47).The Ecc of calcification in benign lesions were lower than those in malignant lesions (U=183.000,P＜0.01).Under the cut-off value of 1.00,benign calcifications were more likely to lie inner 1/2 part of lesion [61.70％(29/47)],while malignant calcifications were more likely to lie outer 1/2 part of lesion [77.78％(14/18)].The difference was statistically significant(x2=8.117,P＜0.01).Under the cut-off value of 1.72,the resultant sensitivity,specificity,accurate rate were 83.1％,77.8％,81.5％ respectively.The area under the ROC was 0.804.Conclusions Ecc exhibits the location characteristics of calcification and may be an ideal parameter in quantitative diagnostic modeling for providing evidence of quantitative diagnosis.

Objective To observe the different cerebral activations between pre-administration and post-administration of tryptophan-depleted amino acid mixture (TRP-)/balanced amino acid mixture (BAL) in healthy volunteers through functional magnetic resonance imaging (fMRI) when they received electrical stimulation at the same time. Furthermore, the effects of 5-hydroxytryptamine (5-HT) were explored in pain modulation network. Methods Two-phase crossover design was adopted. Six right-handed healthy volunteers participated in the experiment. TRP- and BAL were administered to each participant according to the Young's method. Volunteers were scanned under fMRI with or without administration of TRP- or BAL when receiving electrical stimulation simultaneously. Analysis of functional neuroimages (AFNI) software was used to show the different activations in the human brain between pre- and post-administration of TRP-/BAL. Then all the results were analyzed by SPSS 14.0. Results (1) Bilateral primary somatosensory cortex (SⅠ) and secondary somatosensory cortex (SⅡ) were activated during pre-administration and post-administration of TRP-, but the activated volumes of bilateral SⅠ and SⅡ during post-administration of TRP- were found significantly larger than that during pre-administration of TRP (P＜0.05). (2) All the activated regions showed no difference between pre- and post-admini-stration of BAL. (3) There were significant differences of pain threshold between pre- and post-admini-stration of TRP- (P＜0.01), which meant that pain threshold reduced remarkably after TRP- administration, while it showed no difference between pre- and post-administration of BAL (P＞0.05). Conclusion 5-HT plays an important role in pain modulation in the central nervous system, TRP- causes acute tryptophan depletion (ATD) through reducing the level of 5-HT in the human brain, which can induce the decrease of volunteers' pain threshold. The activated volumes of bilateral SⅠ and SⅡ display signi-ficant difference between pre- and post-administration of TRP-, suggesting these brain areas may not only involve in the 5-HT related activities but in pain modulation network as well.

Objective To develop a classification tree algorithm to improve diagnostic performances of 99mTc-MIBI SPECT/CT fusion imaging in differentiating solitary pulmonary nodules (SPNs). Methods Forty-four SPNs, including 30 malignant cases and 14 benign ones that were eventually pathologically identified, were included in this prospective study. All patients received 99Tcm-MIBI SPECT/CT scanning at an early stage and a delayed stage before operation. Thirty predictor variables, including 11 clinical variables, 4 variables of emission and 15 variables of transmission information from SPECT/CT scanning, were analyzed independently by the classification tree algorithm and radiological residents. Diagnostic rules were demonstrated in tree-topology, and diagnostic performances were compared with Area under Curve (AUC) of Receiver Operating Characteristic Curve (ROC). Results A classification decision tree with lowest relative cost of 0.340 was developed for 99Tcm-MIBI SPECT/CT scanning in which the value of Target/Normal region of 99Tcm-MIBI uptake in the delayed stage and in the early stage, age, cough and specula sign were five most important contributors. The sensitivity and specificity were 93.33% and 78. 57e, respectively, a little higher than those of the expert. The sensitivity and specificity by residents of Grade one were 76.67% and 28.57%, respectively, and AUC of CART and expert was 0.886±0.055 and 0.829±0.062, respectively, and the corresponding AUC of residents was 0.566±0.092. Comparisons of AUCs suggest that performance of CART was similar to that of expert (P=0.204), but greater than that of residents (P<0.001). Conclusion Our data mining technique using classification decision tree has a much higher accuracy than residents. It suggests that the application of this algorithm will significantly improve the diagnostic performance of residents.

Objective To evaluate the extent and anatomic distribution of air trapping in lung in young asymptomatic female subjects to achieve early diagnosis of small airway diseases.Methods Fifty young females with normal pulmonary function were included retrospectively in this study.All subjects underwent both inspiratory and expiratory CT scans,the percentage of the area of air trapping(AT)and the percentage of the area of emphysema(Emph)were quantitatively analyzed.Comparison between bilateral lungs was analyzed using independent-samples t test;Comparisons among lobes were done using one-way ANOVA or Kruskal-Wallis rank sum test;Pairwise comparisons between lobes were conducted using LSD test or paired comparison;The effects of each lobe on AT were analyzed using Spearman's rank correlation coefficient,simple linear regression and multiple stepwise regression.Results There was a certain degree of air trapping in lung and a small amount of emphysema in young asymptomatic females.Air trapping was mainly located in the right middle lobe (RML)and bilateral upper lobes.The ratio of air trapping to volume was the highest in RML and the change of air trapping in the bilateral upper lobes had the greatest influence on the air trapping degree of the whole lung.Conclusion There is a certain degree of air trapping in lung in young asymptomatic females.The occurrence and development of air trapping in RML may be a sensitive biomarker for the early detection of pathophysiological changes in small airway diseases using imaging procedures.

Objective To establish and validate a voxel-based method for the quantitative detection of air trapping (AT),and to explore its diagnostic value by preliminarily apply this method in chronic obstructive pulmonary disease (COPD) patients.Methods From March 2015 to February 2016,fifty healthy young volunteers and eighteen COPD patients who underwent both end-inspiratory and end-expiratory CT were included from the Digital Lung Multi-center Study.The quantitative parameters of AT and emphysema were measured by both the voxel-based quantitative method and the conventional threshold method,respectively.All subjects underwent pulmonary function examination within 3 days after CT examination.For healthy volunteers,paired sample rank-sum test was used to compare the difference of quantitative parameters between voxel-based method and threshold method,Spearman rank correlation analysis was used to investigate the correlation between quantitative parameters of the two methods and pulmonary function.For COPD patients,the distribution and extent of AT and emphysema in patients with similar degree of pulmonary function (PFT) injury were observed.Results There were varying degrees of AT in the asymptomatic youth,with a median value of 5.70％ for the voxel-based method and with a median value of 7.96％ for the conventional threshold method,there was significant difference(Z=-4.015,P＜0.001).The correlation between AT and emphysema parameters of the voxel-based method and PFT parameters (r=-0.399 and-0.494,-0.335 and-0.439 separately,P＜0.05) were higher than that of the conventional threshold method,respectively (r=-0.357 and-0.453,-0.284 and-0.391,respectively;all P＜0.05).Furthermore,the voxel-based method can classify COPD patients with similar degree of pulmonary function injury into three subtypes:AT-dominant,emphysema-dominant,and mixed.Conclusions The voxel-based AT quantitative measurement method not only has high sensitivity and accuracy,but also provides imaging phenotype for the diagnosis of COPD and provides assistant decision-making for clinical management.