Objectives To investigate the feasibility of the quantitative analysis parameters of dynamic contrast-enhanced MRI (DCE-MRI) in the diagnosis of prostate cancer and to correlate Ktrans, Ve and kep with histological grade (Gleason score) and serum prostate specific antigen (PSA). Methods MR examinations were performed in 38 patients confirmed by biopsy. ROI were drawn on areas of cancerous foci,noncancerous foci in the peripheral zone and central gland to measure the values of Krans, Ve and kep. The values of the three parameters in different tissue were compared with ANOVA. The correlations between the pharmacokinetic parameters and Gleason score, PSA were assessed with Pearson correlation. Results The Ktrans, Ve, kep values of cancerous foci were (0. 35 ± 0. 26 )/min, ( 0. 185 ± 0. 080 ), ( 1.42 ± 0. 53 )/min,respectively, while (0. 07 ± 0. 05 )/min, ( 0. 040 ± 0. 024 ), (0. 50 ± 0. 18 )/min for noncancerous foci in the peripheral zone and (0. 19 ±0. 06)/min, (0. 161 ± 0. 062), (0. 94 ±0. 25) /min for noncancerous foci in the central gland, respectively. The differences between the three parameters of cancerous foci,noncancerous foci in the peripheral zone and central gland were statistically significant ( F = 16. 267,44. 084, 36. 095, respectively; P ＜ 0. 01 ). No significant correlations were found between any parameter and either Gleason score or PSA (r =0. 279,0.069, 0. 109, -0. 175, -0.067,0. 137, respectively;P ＞0. 05). Conclusion Quantitative analysis parameters of DCE-MRI are feasible in diagnosing prostate cancer. They may be useful in differentiating prostate cancer from benign prostatic diseases.

Objective To evaluate the diagnostic performance of enhancement value and morphological features by using mul-tiphasic MDCT on differentiating untypical T4a from T3 gastric cancer.Methods Fifty-one histopathologically proven T3 and T4a gastric cancer patients with smooth serosa were collected retrospectively.Three radiologists read all images regarding morphological features,while the CT value and enhancement value of regions of interest (ROIs)located in the outer of lesion were calculated.Cut-off analysis was performed to determine optimal threshold levels of enhancement value to discriminate T4a and T3 gastric cancer.Di-agnostic performance of enhancement value and combination of enhancement value and morphologic assessment were compared with morphologic assessment by means of receiver operating characteristic (ROC)curve analysis.Results The sensitivity and specificity of morphological features was 66.67% and 33.33% respectively;the area under the ROC of enhancement value (between venous phase and plain scan)for differentiating T4a from T3 gastric cancer was 0.82,with a cut-off at 43.6 HU,sensitivity of 74.07% and specificity of 70.83%.Combined conventional standard and enhancement value,sensitivity of 100.00% and specificity 26.31%. Conclusion For differentiation of T4a and T3 gastric cancer by means of MDCT,enhancement value is found to be superior to con-ventional standard.

External apical root resorption is among the most common risks of orthodontic treatment, and it cannot be completely avoided and predicted. Risk factors causing orthodontic root resorption can generally be divided into patient- and treatment-related factors. Root resorption that occurs during orthodontic treatment is usually detected by radiographical examination. Mild or moderate root absorption usually does no obvious harm, but close attention is required. When severe root resorption occurs, it is generally recommended to suspend the treatment for 3 months for the cementum to be restored. To unify the risk factors of orthodontic root resorption and its clinical suggestions, we summarized the theoretical knowledge and clinical experience of more than 20 authoritative experts in orthodontics and related fields in China. After discussion and summarization, this consensus was made to provide reference for orthodontic clinical practice.
Humans ; Tooth Movement Techniques/adverse effects* ; Root Resorption/etiology* ; Consensus ; Dental Cementum ; Risk Factors