Objective To evaluate the capability of SSH/RAD MRH based on SENSE to show gastrointestinal tract anatomic structure,to provide normal anatomic base for gastrointestinal tract disease diagnosis with SSH/RAD MRH and to explore the new examination method for imaging diagnosis in gastrointestinal tract disease.Methods There were 30 healthy volunteers in total including 19 male cases,11 female cases,the age ranging from 20 to 50 with the mean age as 35 year old.All volunteers were asked to drink tap water about 1000-1500mL continuously at 60 minute before examination,to drink tap water 500mL at 20 minute before examination and receive injection of 654-2 10mg in muscle at 10min before examination.MRH were performed by Philips Gyroscan Intera 1.5T superconduct MRI scanner,using SENSE technique,phased-array coil and breath hold.SSH/RAD MRH was performed after the routine abdominal MR scan was done.Results SSH/RAD MRH was successfully performed on all volunteers at one time,and the examination achievement ratio was 100%.All images were evaluated by two senior doctors using blindness method.The ratio of the good-optimal quality images was 93% and the poor-quality images was 7%.Of all images,the stomach manifestation ratio was 65%,the stomach mucous clear manifestation ratio was 80%,the duodenum manifestation ratio was 80%,the jejunum manifestation ratio was 59%,the jejunum diameter was 2-2.5cm,the ileum manifestation ratio was 21%,the ileum diameter was 1.5-2.5cm and the small intestinal mucous clear manifestation ratio was 67%;the colon manifestation ratio was 10% and the colon mucous clear manifestation was 6%.Conclusion SSH/RAD MRH based on SENSE can clearly show the outline and mucous of the stomach,duodenum and jejunum,but can not clearly show the outline and mucous of ileum and colon.The imaging examination that the colon SSH/RAD MRH combined with the routine abdominal MR scan could clearly and conveniently show the anatomical characteristics of gastrointestinal tract.It is a new imaging examination method for gastrointestinal tract examination.

Objective To show the feasibility and value in the diagnosis of airway obstruction and pulmonary embolism with MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging. Methods Eight canines were implemented for peripheral pulmonary embolism by intravenous injection of gelfoam granules at pulmonary segmental arterial level, and five of them were formed airway obstruction models by inserting self-made balloon catheter at second-bronchia. The oxygen-enhanced MR ventilation imaging was introduced by subtracting the images of pre- and post- inhaled pure oxygen. The MR pulmonary perfusion imaging was achieved by the first-pass contrast agent method. Moreover, the manifestation of MR ventilation and perfusion imaging was observed and contradistinguished with that of general pathologic anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results The manifestations of airway obstruction regions in MR ventilation and perfusion imaging were matched, but those of pulmonary embolism regions were dismatched. The defect range of airway obstruction in MR ventilation image was smaller than that in ventilation scintigraphy. The abnormal perfusion regions of pulmonary embolism were divided into defect regions and reduce regions based on the time courses of signal intensity changes. The sensitivity and specificity of diagnosis on pulmonary embolism by MR ventilation combined with perfusion technique were 75.0% and 98.1%. The diagnostic results were in good coherence with ventilation-perfusion scintigraphy and pulmonary angiography(K=0.743, 0.899). Conclusion The MR oxygen-enhanced ventilation combined with pulmonary perfusion imaging can be used to diagnose the airway and vascular abnormity in lung. This technique resembles the ventilation-perfusion scintigraphy. It can provide quantitative functional information and better spatial and temporal resolution, and possesses the value of clinical application.

Objective To evaluate the frequently used electrocardiographic criteria and propose a modified algorithm for differentiating typical atrioventricular node reentrant tachycardia(AVNRT)from atrioventricular reciprocating tachycardia(AVRT).Methods Twelve-lead electrocardiograms(ECGs)during sinus rhythm and atrioventricular node reentrant tachycardia(AVNRT)or atrioventricular reciprocating tachycardia(AVRT)with a narrow QRS complex were obtained from 154 patients who had received successful radiofrequency catheter ablation from Jan.2003 to Nov.2005.The ECGs of initial 104 patients were analyzed by 3 observers without knowledge of the electrophysiological diagnosis.According to these initial results,we proposed a modified stepwise ECG algorithm which used pseudo r′/S/Q waves,RP interval,and ST-segment elevation in lead aVR during tachycardia.Two observers assessed the algorithm in additional 50 patients.Results The algorithm was able to increase the overall accuracy from 77% and 79% with original algorithm to 84% and 87% with the modified algorithm,respectively.The inter-observer concordance was 85%.The intra-observer concordance was 89% in both investigators.Conclusion The modified algorithm can improve the accuracy of differential diagnosis between typical AVNRT and AVRT via concealed accessory pathway.

Objective To establish the database of diameter and length of the pulmonary artery branches in different phase of cardiac cycle in healthy adult chest MDCT.Methods Normal enhanced chest MDCT with ECG-gating was selected and slab thin slice maximaun intensity projection(STS MIP) reconstruction were performed in different periods on ECG represent systole and diastole respectively.The diameter and length of pulmonary artery on the plane which showed the whole length of the aim artery were measured.Doppler UCG with ECG-gating was performed in healthy adults to measure the inner diameter of pulmonary trunk and right and left pulmonary artery in different phases of the cardiac cycle as contrast method.Results Normal enhanced chest MDCT with ECG-gating showed the diameter in systole period of the main pulmonary artery was larger than that in diastole period,while it went conversely to that of the proximal part of two pulmonary arteries,distal part of the right pulmonary artery,right media-lobe artery,both S10 segmental arteries and the difference were statistic significantly,only the length in diastole period of the right upper lobe artery was larger than that in systole period.The distance between the measured point of the main artery and the right one showed larger in diastole than systole period.On ECG-gating UCG,in addition to that the diameter change of the main pulmonary artery during the two periods were coincident with MDCT,the two pulmonary artery had no significant difference during the two periods.Conclusion It is necessary using branching geometry data of the main artery to segmental arteries in different period of the cardiac cycle with normal enhanced chest MDCT for flowing model building of pulmonary artery.

Objective To probe the mechanism of Warlker-256 cell apoptosis resulted from permanent and strong magnetic field. Method The amplification, rearrangement, deletion, transcription and expression of P53 were detected in 320 rats treated by magnetic field and 80 controls, using Dot Blot of DNA and RNA, Southern and Northern blot, and immunohistochemical technologies. Results P53 is wild type in Warlker-256 cells, no amplification, rearrangement and deletion were found in either magnetic treated group or control group. The transcription and expression of P53 is significantly enhanced in the treated group versus the control(P

Objective To compare the diagnostic efficiency in showing the responsible blood vessels for neurovascular compression in patients with trigeminal neuralgia by 3D‐FIESTA‐C and 3D‐TOF‐MRA sequences .Methods The imaging data of 60 patients with primary trigeminal neuralgia were analyzed retrospectively .After MRI examination ,all of the patients underwent micro‐vascular de‐compression (MVD) .3D‐TOF‐MRA and 3D‐FIESTA‐C sequences were performed to evaluate the three‐dimensional relationship be‐tween trigeminal nerve and blood vessels through the original and reconstructed image .The intraoperative endoscopic findings were set as the gold standard comparing to the manifestations of 3D‐TOF‐MRA and 3D‐FIESTA‐C .Results The sensitivities of 3D‐TOF‐MRA and 3D‐FIESTA‐C for the diagnosis of the existence of responsible vessels were 85 .7% ,89 .3% ,the specificities were 75 .0% , 100% ,and the accuracies were 85 .0% ,90 .0% ,respectively (P=1 .000) .Furthermore ,the sensitivities of 3D‐TOF‐MRA and 3D‐FIESTA‐C for the diagnosis of the existence of responsible arteries were 94 .1% ,88 .2% (P=0 .244) ,while the sensitivities of the responsible veins were 0 .00% and 88 .2% (P=0 .009) .Conclusion Both the 3D‐FIESTA‐C and 3D‐TOF‐MRA sequences can accurately deter‐mine the existence of responsible vessels in trigeminal neuralgia before surgery .3D‐FIESTA‐C sequence is superior to 3D‐TOF‐MRA for presenting the responsible veins ,which can be used as a supplemental diagnostic tool before operation .

Acute cerebral infarction is a common disease of the central nervous system, the key of the current treatment is to restore blood flow and save ischemic penumbra .The studies have shown that good collateral circulation can reduce the infarction area, improve prognosis.Thus, an accurate and complete evaluation of collateral circulation in the early stage of disease has an important sig -nificance.The development of modern imaging techniques provides important means for the assessment of collateral circulation estab -lishment in acute stroke .In this paper, techniques and methods of the imaging examination of collateral circulation establishment in a -cute cerebral infarction and methods are reviewed, aiming to provide the basis for choosing reasonable imaging modality .

Objective To explore the consistency of knee articular cartilage defect area by magnetic resonance imaging (MRI)and arthroscopy.Methods Thirty-six patients (36 knees)with knee cartilage lesions were collected in our study.The defect area meas-urement of knee articular cartilage by MRI and arthroscopy was compared.Results A total of 92 lesions were detected by both MRI and arthroscopy with an average of 2.6 defects per knee.Preoperative MRI resultes demonstrated the mean defect area per knee was (1.9±1.5)cm2 ,while arthroscopic measurement after debridement indicated the mean defect area per knee was (2.9±2.6)cm2 , which had significant difference(P <0.001).The area measured by MRI was less than that by arthroscopy,and the mean difference was (1.7 ± 1.1)cm2 .The mean area measured by MRI was 70.1% of that by arthroscopy.Conclusion Arthroscopy and MR have good consistency in the number of articular cartilage defect lesions .MRI can reflect the knee articular cartilage defect area directly or indirectly,and be capable of accurate positioning and qualitative diagnosis.

Objective To evaluate the relationship between the spatial structure of pulmonary vascular tree and oxygen partial pressure in patients with chronic obstructive pulmonary disease(COPD) by the fractal dimension method.Methods 106 patients with COPD and 100 healthy people without COPD as controls were included in this study.All of the patients underwent multidetector CT scan and blood gas analysis.The pulmonary vascular trees were generated using post-processing software,and the FD of the pulmonary vascular trees were determined with ImageJ software in a personal computer.The fractal dimension were evaluated in the two groups.The relationship between FD and oxygen partial pressure in patients with COPD was analyzed.Results The FD value of the patients with COPD was lower than that of the patients without COPD (t =5.21,P＜ 0.01).There was a significant correlation between FD and the PaO2 in patients with COPD (r=0.692,P＜ 0.01).Conclusion FD analysis can effectively evaluate the process of pulmonary vascular remodeling induced by hypoxia in patients with COPD,which may be used as an important index for quantitative evaluation of pulmonary vascular remodeling in the course of COPD.

Objective To build an advanced clinical case collection and teaching system for the department of radiology, and thus to facilitate the scientific research and teaching.Methods By combining several free software, we built a network version of the case collection system with simple web pages, to achieve centralized storage of case text and image data, thus to facilitate the research and teaching work.Results This case collection system quickly saved text data and image data through simple operation, supported parallel work without the need for complex configuration on the client, and had good support for wide area network.This system had stable system operation and could be customized to meet the clinical needs well.Conclusion Using free software to establish the network version of the case collection and teaching system is low cost and has no legal risk.This system is a simple but powerful tool, and can meet the needs of hospitals with different sizes, which is a more perfect case collection system.