Objective To investigate the clinical value of iPass in three dimensional contrast enhanced MR angiography (3D-CE-MRA). Methods iPass were performed in 32 cases, including cervical vessel (4 cases), pulmonary vessel (7 cases), abdominal vessel (18 cases), and femoral vessel (3 cases). iPass bolus tracking was run before 3D-CE-MRA. The tracking sequence was operated repeatedly with real time display of image. The peak of bolus arrival time(Tp), identified with signal of target vessel increased 30% over baseline, was automatically loaded in the timing page of 3D-CE-MRA, and the time of scan delay(Td) was computed by the system with Tp. The acquired images were subtracted and reconstructed by MIP. The quality of MIP image was evaluated. Results The iPass bolus tracking sequence and 3D-CE-MRA were completed successfully in 29 cases. The bolus tracking couldn′t detect the bolus arrival time in 3 cases, but they were completed through changing ROI and bolus tracking repeatedly. The average score of 3D-CE-MRA MIP image was 3.81?0.59. Conclusion iPass can provide the exact Tp and automatically control Td of 3D-CE-MRA. iPass is a useful procedure to improve the image quality and provide the specific scanning scheme for 3D-CE-MRA.

OBJECTIVETo investigate the insulin-like growth factor-I (IGF-I) gene and polypeptide expression in cultured rat osteoblast (ROB) and the role of IGF-I in mediating the cell-to-cell communication by mimicking the pharmacokinetics of parathyroid hormone (PTH).

METHODSThe ROB was cultured with three kinds of treatment: (1) Control (Ctr), the cells were cultured without PTH during the first 6 hours and the subsequent 42 hours in a 48-hour cycle; (2) Intermittent exposure to PTH (Itm), the cells were cultured with PTH during the first 6 hours, but without PTH in the subsequent 42 hours; and (3) Continuous exposure to PTH (Ctu), the cells were cultured with PTH during the first 6 hours and the subsequent 42 hours.

RESULTSThe bone-forming activities of ROB were increased in Itm and inhibited in Ctu. The IGF-I mRNA content in Itm cells was elevated only during the first 6 hours and that in Ctu cells was elevated at any time during an incubation cycle. The free IGF-I concentration in the medium of Itm cells was generally higher and that of the Ctu cells was generally lower compared with those of the Ctr cells. The IGF-I antibody significantly reduced the alkaline phosphatase activity within the cells of Ctr and Itm.

CONCLUSIONSPTH rapidly and constantly stimulates the IGF-I gene transcription of osteoblast. There was an obvious discrepancy between the IGF-I mRNA content within the osteoblast and the free IGF-I level around the osteoblast in either mode of PTH action. The IGF-I might be important for osteoblast-osteoblast communication and bone-forming activity, not only in intermittent PTH administration, but also in the physiological functioning of osteoblasts.

Animals ; Cells, Cultured ; Gene Expression ; drug effects ; Insulin-Like Growth Factor I ; genetics ; physiology ; Osteoblasts ; Parathyroid Hormone ; pharmacology ; Peptides ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Transcription, Genetic ; drug effects

Objective To investigate the effect of scan table on size-specific dose estimate ( size-specific dose estimate, SSDE) in children's CT scan. Methods CT imaging data and CTDIvol of 44 children ( 15 heads, 13 chests, 16 abdomen-pelvis) who underwent Siemens SOMATOM Definition AS+ 64 row 128-slice CT scan were retrospectively collected. CTDIvol of each patient was recored, WED ( water equivalent diameter) was calculated by two different methods ( with or without table) , donated as WED-T and WED-NT, then the corresponding SSDEWED ( SSDEWED-T and SSDEWED-NT ) was calculated. And the SSDEWED-NT was used as reference to evaluate the difference between WED and SSDEWED obtained by two different methods. Results Including part of table will lead to the overestimate for WED, with mean differences of 0. 10％, 2. 82％ and 2. 54％ for head, chest and abdomen-pelvis, respectively, while SSDEWED will be underestimated by 0. 06％ ( head ) , 2. 70％ ( chest ) and 1. 59％ ( abdomen-pelvis ) . Conclusions Including par of the patient table has a certain effect on SSDEWED for children, more attention should be paid for the application of SSDEWED.

Objective:To analyze the effects of radiotherapy on the onset and progression of mastoiditis in patients with nasopharyngeal carcinoma (NPC) using magnetic resonance imaging (MRI) and to explore the risk factors for the onset of mastoiditis after radiotherapy.Methods:The onset and progression of mastoiditis of 204 NPC patients 3, 12, and 24 months after radiotherapy were analyzed based on MRI images. The multi-factor logistic regression analysis was applied to explore the risk factors of the onset of mastoiditis after radiotherapy. The cross-sectional area of the tensor veli palatini muscle was measured and the relationship between the atrophy degrees of the tensor veli palatini muscle and the onset of mastoiditis was analyzed.Results:The incidence of mastoiditis before radiotherapy was 20.6% (84/408, ears), and was 41.1% (168/408, ears), 22.3% (91/408, ears), and 19.6% (80/408, ears), respectively 3, 12, and 24 months after radiotherapy. The incidence of radiotherapy-induced mastoiditis was 35.8% (116/324, ears), 18.2% (59/324, ears), and 16.4% (53/324, ears), respectively 3, 12, and 24 months after radiotherapy. The remission rate of 63 patients (83 ears) who developed mastoiditis 3 months after radiotherapy was 63.9% (53/83, ears) and 75.9% (63/83, ears), respectively 12 and 24 months after radiotherapy. The remission rate of 54 patients (60 ears) who suffered mastoiditis before radiotherapy was 43.3% (26/60, ears), 65.0% (39/60, ears), and 73.3% (44/60, ears) 3, 12, and 24 months after radiotherapy. The multivariate analysis showed that the independent risk factors for radiotherapy-induced mastoiditis included age ≥50, clinical stages Ⅲ-Ⅳ, radiotherapy dose > 70 Gy, and tumors invading pharyngeal ostium of the eustachian tube. In addition, the atrophy degree of tensor veli palatini muscle 12 and 24 months after radiotherapy correlated with the onset of mastoiditis.Conclusions:The incidence of mastoiditis significantly increased 3 months after radiotherapy and significantly decreased 12 months after radiotherapy for NPC patients. The natural remission rate of radiotherapy-induced mastoiditis 12 months after radiotherapy was over 70%. The independent risk factors for radiotherapy-induced mastoiditis include age ≥50, clinical stages Ⅲ-Ⅳ, radiotherapy dose >70 Gy, and tumor invading pharyngeal ostium of the eustachian tube. The atrophy degree of the tensor veli palatini muscle 12 and 24 months after radiotherapy correlates with the onset of mastoiditis.