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.

Objective To assess clinical applications of using diffusion-weighted imaging(DWI) in encephalic infection diseases.Methods 10 patients with encephalic infection diseases were investigated from September 2004 to June 2007.All patients underwent routine MRI and single-shoot DWI in which the thickness and space of routine MRI agreed with DWI.The ADC values at infection focus and opposite normal region were measured.Results Among the 10 cases,seven of them showed decreased ADC value when DWI presented hyper-intensity;whereas the other three,whose chronic infection were long-term,had increased ADC value while DWI presented iso-/hypo-intensity.Conclusion MRI diffusion-weighted imaging plays an important role in the diagnosis of encephalic infection diseases.