Objective To analyze the effects of image quality and radiation dose of the patients with no heart rate control on different acquisition window settings.Methods A total of 75 patients underwent CTCA scan,with a median age of 55 years.All patients had no heart rate control.HR≤65 beats per minute acquisition phase setting was from 65%to 75%,65 beats per minute80 beats per minute acquisition phase setting was from 35%to 45%.Evaluated patients radiation dose and subjective image quality of coronary artery.Results 75 patients with ED was (2.44±1.21)mSv,group A was (1.54±0.41)mSv, group B was (3.57±0.53)mSv,group C was (1.64±0.27)mSv,group A vs group B(P=0.000),group A vs group C(P=0.854),group B vs group C(P=0.000).A total of 1 043 coronary artery segments of 75 patients were evaluated,with an average of 13.9 segments showed by every case,(3.66±0.51)scale.Group A was (3.75±0.44)scale,group B was (3.60±0.54)scale,group C was (3.38±0.67) scale,group A vs group B(P=0.000),group A vs group C(P=0.004),group B vs group C(P=0.032).Conclusion The prospective ECG gated sequence scan could obtain the image quality and avoid unnecessary radiation dose by adapting to the different heart rate.

Objective To evaluate the functional alternations of canine renal ischemia and reperfusion injury by using MR perfusion-weighted imaging, and to correlate the imaging with the pathologic findings. Methods Using 1. 5 T MR system, four groups of three anesthetized dogs each were studied by left renal artery ligation for 30-, 60-, 90-, and 120-min, respectively, after the removal of ligation, reperfusion injury was suffered for one hour. True-FISP, TSE, and EPI sequences were performed in five different time phases ( pre-ischemia, onset-ischemia, post-ischemia, onset-reperfusion, and post-reperfusion). Finally, IR-turbo-FLASH sequence (TR 5. 8 ms, TE 3. 2 ms, TI 400 ms, FA 12?) with a temporal resolution of 1. 16 s was performed. Signal intensity (SI) in cortex, outer medulla, and inner medulla was measured. SI was plotted as a function of time. Peak height (P) , time to peak (Tp) , and the area (A) under the time-course curves after the intravenous injection of Gd-DTPA were estimated. Blood and urine examples were collected for measuring serum creatinine level and urinary protein before and after the insult. Histologic examination was performed with light and electron microscopy in all dogs. Results After arterial ligation,there was marked and significant reduction in the SI of each layer of left kidney on true-FISP, TSE, and EPI, except for the SI of inner medulla on TSE. After the removal of ligation,there were no significant differences in the SI of cortex of both kidneys, however, significant differences in the SI of outer and inner medulla of both kidneys remained on EPI in all groups. The turbo-FLASH study clearly depicted the three-phase pattern of SI changes in each layer on right kidney. The uniphasic enhancement pattern in all groups was showed in outer and inner medulla on left kidney, with the area under the curve decreased. Conclusion This preliminary study shows that MR perfusion-weighted imaging may be useful and very promising for the evaluation of renal dysfunction following normothermic ischemia and reperfusion injury.

Objective To evaluate the image quality and obtained by the tube current modulation base on time bolus peak in low voltage in CTPA.Methods 30 consecutive patients suspected pulmonary embolism(PE)were prospectively enrolled,and satisfy the following conditions.The study was performed by 64-slice spiral CT system (lightspeed VCT-XT,GE healthcare),Tube voltage was set at 80 kV.Tube current settings related to the attenuation of ROIs by test bolus peak.The injection parameters were set up by injection flow rate (4 mL/s),contrast medium dose (28 mL),and saline flushing dose (40 mL).All images were evaluated by two observers blinded to pulmonary CTA protocol,including attenuation,noise,SNR and CNR.The image quality was evaluate by 4-score.To evaluate the relationship between influential factor and image quality using Pearson correlation analysis.A P-value <0.05 was considered to indicate a statistically significant difference.Results The time bolus peak was statistically significant influence on attenuation(r=0.398,P =0.029).There was no statistically significant influence on noise (r=0.104,P =0.583),signal-to-noise ra-tio (r=0.263,P =0.1 60)and contrast-to-noise ratio(r=0.299,P =0.109).The other factors(BM,BMI and BSA)was no statisti-cally significant influence on the image quality(P > 0.05 ).The mean attenuation,noise,SNR and CNR on pulmonary trunk was (628.63±146.46)HU,(53.92±14.07)HU,12.02±3.1 7 and 10.81±3.10,respectively.The percentage of assessable pulmonary arteries was 95.82%.Conclusion The tube current modulation base on time bolus peak in low voltage could offer assessable image quality and raise image stability.

Objective To evaluate the clinical,pathological and imaging features of basal cell adenoma in the parotid. Methods The clinical,pathological and CT imaging data of 21 cases with parotid basal cell tumor confirmed by operation and pathology were retrospectively analyzed. Results All 21 patients(5 male,16 female ) had solitary BCA lesion,which located at the superficial lobe of parotid gland(n=17)and involved both the superficial and deep lobe(n=4). Twelve lesions were well-defined and cystic degeneration was displayed in 9 le-sions,3 lesions had punctate calcification at the edge of tumor. All lesions were significantly enhanced,the enhancement of BCA in the ve-nous phase was close to the arterial phase. Conclusion The CT features of BCA in parotid gland are characteristic,which is helpful to make qualitative diagnosis when in combination with clinical features.

AIM: To determine the effect of heat treatment on rat primary cultured neurons, and give fundamental research for candidate molecule to protect the neurons from heat injury. METHODS: Neurons from rat striatum were primary cultivated in D-MEM with 15% horse serum, and when got mature, cells were identified by immuno-cytochemical staining with neurofilament protein (NF), tyrosine hydroxylase (TH) and neuron specific enolase (NSE) antibodies. Cells in heat treatment groups were put in an 43 ℃ CO 2 incubator for 1 h, and the control groups at 37 ℃ as normal. Striatum neurons were stained with trypan blue and dual fluorscence dye (PI/H33258) immediately followed heat treatment, and necrosis rate of neurons was estimated. At the same time, activated caspase-3 immuno-cytochemical and TdT TUNEL methods were applied to determine apoptosis rate, and cell volume was also identified with micro-photography. RESULTS: During day 7 to day 9, the cultured striatum neurons got mature, and many neuronal fibers starched out and formed neuron network, NF, TH, and NSE staining positive. Treatment at 43 ℃ for 1 h, cell number decreased greatly, while NF+ percentage kept unchanged, and the heat treatment survived neurons were processing cell necrosis and apoptosis, but necrosis percentage was much greater than that of apoptosis. While cell volume kept unchanged after heat treatment. CONCLUSION: Heat treatment greatly affects the growth and survival of the cultured striatum neurons, and the injury effect is most due to cell necrosis process.

Extramural vascular invasion of rectal cancer is an important factor affecting the prognosis of patients with rectal cancer. Accurate diagnosis of extramural vascular invasion before surgery can guide the formulation of treatment plans, thereby improving prognosis and long-term survival of patients. Magnectic resonance imaging examination and computed tomography examination are the main examination methods for preoperative evaluation of rectal cancer. The authors review the role of imaging examinations in the evaluation of extramural vascular invasion of rectal cancer.