Objective To improve children′s radiation dosage through adjusting CT head scanning parameter. Methods During December 2006 to June 2007,292 cases were selected at random to adjust CT head scanning parameter, mainly for charge of voltage, tube current and scan time. At the same time,all images were appraised by two doctors. Results Adjustment of children′ s head scanning parameter could reduce the radiation dosage obviously, and no influence for diagnosis. Conclusion It′s no affect for diagnosis to improve children′s head CT scanning parameter, and leads reduction of CT dosage obviously.

Objective To establish the simultaneous determination of arsenic and mercury in the drinking water by hydride generation atomic fluorescence spectrometry (HGAFS). Methods The contents of trace arsenic and mercury in drinking water were detected by HGAFS based on optimized working conditions in this assay. The influences of some factors, such as sample pretreatment, pH value and interfering ions in drinking water were analyzed also. Results The detection limit of arsenic, mercury was 0.29 ng/ml and 0.05 ng/ml respectively. The precision (relative standard deviation) of the method was less than 6.8% .The recovery rates ranged from 85.7%～112.6%. The detecting results for standard materials were very much close to the reference values. Conclusion This method was suitable for the detection of arsenic and mercury in drinking water.

Objective To probe the technique and clinical applications of spiral CT (SCT) scan in urinary system. Methods 40～80 ml angiografin was injected into the vein by high voltage injection in six cases,and 5～10 minute later, SCT scan was performed. The original data were sent to workstation, then reconstructed. 3D pictures of urinary system including renal calyx, ureter and bladder were clearly demonstrated in all cases. Results Of 6 cases, there were 3 ones with ureter stone,1 case with kidney calyx cancer, and 2 case with ureter repetitive. Conclusion CTU is a safe, convincible, convenient and fast technique. It may provide high resolving urinary tract image and will be a kind of non-injury imaging technique in diagnosing the diseases of urinary system.

Objective To discuss the clinical application of rotational DSA and its advantages. Methods 35 cases undergoing cerebral angiography and hepatic arteriography were performed with standard DSA, of which, 24 ones were performed with rotational DSA. Results Standard DSA could only display partial lesion at lateral side, while rotational DSA could display the pathological structure and surrounding structure. Conclusion Rotational DSA is valuable for the diagnosis and treatment of encephalic angioma and liver tumor.

Studies using isolated rat fundus strip preparation demonstrated that l-stephanine ( l-STP ) , l-roemerine ( 1-REM ), l-stepholidine (l-SPD), 1-tetrahydropalmatine ( l-THP ) and dl-tetrahydrode-berine ( THB ) possessed 5-HT blockade properties. 1-STP ( 16, 25 ?M ) produced competitve antagonism against 5-HT receptor on rat fundus, while higher concentration ( 50 ?M ) suggested a non-competi tive inhibition, with pA2' and2' values equal to 5.8 and 4.2 respectively. 1-REM was found to be a non-competitive antagonIst ( pD' 2 = 4.5). 1-SPD, 1-THP and THB cuased a parallel shift to the right of 5-HT concentration response curve without any significant changes in their maximum response, indicating that they were competitive antagonists of 5-HT receptor. The antagonistic potencies of 1-SPD, l-THP and THB were expressed as pA2 values: 6.2,5.2 and 5.0.

Complex clinical situation requires healthcare providers to be able to perceive, un-derstand and predict the situation changes correctly, namely they need situation awareness. Good clin-ical situational awareness can help clinical decision-making and cooperation, which is critical to im-proving the quality of healthcare. Therefore this review aims to summarize the meaning, applications, status and influence factors, measurements and training of clinical situation awareness, to provide evidence for training and improving clinical situation awareness.

Objective To solve the limitation of the wide-bound imaging from aortic arch to the bifurcation of internal and external carotid artery by changing 3D TOF MRA scan parameters, and discuss the clinical value of this technology in carotid artery angiography. Methods 108 patients with cerebrovascular disease were performed with carotid artery 3D TOF MRA. Images were performed under MIP, MPR and VR. The images of bilateral common carotid arteries, external and internal carotid artery, and vertebral artery were evaluated interactively by two independent radiologists blinded to results. Results 864 blood vessels were observed with 3D TOF MRA, including 672 normal clearly, 17 unclear, 17 congenital variants, 73 un -smooth lesion, 63 vascular stenosis, 9 vascular occlusion, 5 not display, 4 depressed downward, 4 vascular enlargement. Totally,unclear, variation and lesion blood vessels were 192. The results in combination with original image analysis could meet the need of diagonosis. Conclusion 3D TOF MRA as a noninvasive and non contrast agent imaging method can be used to select the carotid stenosis and is quite good in the value of application.

Objective To study clinical application of no phase wrap(NPW) technique in MRI. Methods 139 patients were selected and performed two sequences with and without no phase wrap in the same condition. The two kinds of images were compared. Results In the same parameter, phase wrap artifacts were seen in all images without the option of NPW. In the opposite, with the option of NPW, the artifacts disappeared. Conclusion NPW can avoid the Phase wrap artifacts .

Objective To discuss the value of Time-Resolved Imaging of Contrast Kinetics (TRICKS) in the diagnosis of lower extremity diseases. Methods 24 cases (27 times) with lower extremity, skeleton and blood vessel diseases undergoing TRICKS were retrospectively analyzed. There were 14 cases with both lower extremities two -segment scan, 5 cases(6 times) with one-segment scan(thigh), and 5 cases (7 times) with one-segment scan(calf). Conventional sequences were performed followed by enhanced MR angiography with the TRICKS technique. Results The TRICKS images for all cases satisfied the vascular changes and structure demonstration in arteriovenous phase, and the full circulative process of those pathological vessels were observed. The diagnostic accuracy of TRICKS angiography has been validated. Conclusion The TRICKS provides a method for imaging the change of blood flow. The vascularity in the target vascular and tumor can also be obtained. Hence TRICKS provide important information in clinical decision making.

Objective To discuss the inspect technique and methods of magnetic resonance urography(MRU)in pediatric urinary system. Methods 16 cases with urinary system diseases were analyzed retrospectively,including axial routine FRFSE T2WI with fat saturation and three-dimensional MRU. The three-dimensional(3D) imaging data were sent to AW4.2 workstation,then edited and reconstructed with maximum intensity projection(MIP) and rebuilt. Results 12 cases in 16 cases were congenital abnormality by MRU diagnosis,3 cases were Urinary system diseases and 1 case was normal. 10 cases in 16 cases were performed with surgical intervention,6 cases with medical treatment,which clinical diagnosis were consistent with MRU. 16 cases were accepted examination with B -ultrasonic,6 cases CT and 9 cases IVP. Diagnose accordance rates with MRU were B-ultrasonic 93.7%(15/16),CT 66.7%(4/6),IVP 66.7%(6/9).Conclusion MRU is a safe,convincible and convenient technique,which can provide high quality imaging,so it will be a kind of non-injury imaging method in diagnosing the diseases of pediatric urinary system diseases.