Objective To evaluate the energy metabolism of normal muscle in different age group.Methods Noninvasive 31P-MRS was acquired from quadriceps muscles in healthy people including 10 adults and 6 juvenile.Peak areas were standardized for longitudinal saturation and coil inhomogeneity.The concentration of phosphomonoesterase(PME),inorganic phosphate(Pi),phosphodiesterase(PDE),phosphocreatine(CrP)and adenosine triphosphate(ATP)was determined from spectra.Concentrations of adenosine diphosphate(ADP)and phosphorylation potential(PP)were calculated from the biochemistry reaction equilibrium.Enzymatically active magnesium ATP complex Mg-ATP and pH value were determined from relative chemical shift.Results Normal muscle had prominent high energy phosphate peaks,the mean concentration of CP and ATP was 24.76 and 18.38 mmol/kg in adults,25.52 and 21.36 mmol/kg in young subject.In comparison with adult group,young subjects had lower PDE and higher ATP values.pH value,magnesium ATP and total magnesium were higher in young subjects too.Pi,CP,ADP,PP,free Mg2+ and free ATP concentration were similar in both group.Conclusion High energy compounds were slightly higher in juvenile subjects.31P-MRS is a noninvasive technique to evaluate energy metabolism in different age group.

Objective To investigate the accuracy and reproducibility of multi echo data imagine combination (MEDIC) sequence with water excitation at 3. 0 T in swine knee cartilage. Methods Sagittal MEDIC sequences (0.6 mm slice thickness, isotropic) were acquired twice at 3. 0 T MRI in 30 swine knees. The knee cartilage was then removed and the volume was directly measured with water substitution method. The cartilage volume was also determined with a validated open source image software OsiriX by two observers ( A and B). The cartilage volumes obtained by two methods were compared. The reproducibility of MEDIC for quantitative measurement was accessed by the root-mean-square (RMS) of variation coefficient. Interobserver and intraobserver precision errors were compared using a paired students t-test. The accuracy of MEDIC for quantitative measurement was determined by the random pairwise differences, systematic pairwise differences and the Pearson correlation coefficients. Time of semiautomatic and manual segmentation were recorded. Results Time was saved about 75% by using semiautomatic segmentation methods [(4.0 ±1.5) min] versus manual segmentation [(16.0 ±0.9) min]. Interobserver precision errors (RMS CV%for paired analysis) between A and B for cartilage volume measurement were (2. 66 ±0. 82) ml and(2. 61 ±0.81) ml, t=0.24, P=0. 81 (patella); (2.40 ±0.69) ml and(2.49 ±0. 85) ml, t= -0.45,P =0. 65 (medial femoral condyle) ;(2. 28 ±0.74) ml and(2.41 ±0. 78) ml, t = -0. 66, P = 0. 51 (lateral femoral condyle);(3.43±1.28) ml and(3. 51 ±1. 08) ml, t= -0.26, P=0.79 (femora trochlea) with sagittal MEDIC. Intraobserver precision errors ( RMS CV% for paired analysis) of observer A for the first and second cartilage volume measurement were(2. 64 ±0. 62) ml and(2. 67 ±0. 60) ml, t = -0.19, P =0. 85(patella); (2.43 ±0.60) ml and(2. 39 ±0.59) ml, t =0.26, P = 0. 80 (medial femoral condyle);(2. 26 ±0. 56) ml and (2. 30 ±0. 57) ml, t = - 0.27, P = 0. 78 (lateral femoral condyle); (3.40 ±1.20) ml and(3.47 ±1. 11) ml, t = -0.23, P = 0. 82 (femora trochlea) with sagittal MEDIC. The cartilage volume of direct measurement were (2.73 ±0.97 ) ml ( patella ) , (2. 28 ±0. 66 ) ml ( medial femoral condyle) ,(2. 18 ±0. 55) ml (lateral femoral condyle) and (3. 39 ±1.31) ml (femora trochlea).Correlation coefficients between MEDIC and direct measurement for cartilage volume measurement were high [r = 0.95, t = 16. 10, P<0.05 ( patella); r=0.92, t = 12.42, P<0.05 (medial femoral condyle); r =0.94, t = 14.58, P < 0.05 (lateral femoral condyle) and r = 0.98, t = 26.06, P < 0. 05 (femora trochlea) ]. Conclusion Using image software OsiriX, sagittal MEDIC sequence permits accurate and precise measurement of cartilage volume at reasonable acquisition and segmentation time at 3.0 T MRI in swine knee.

Objective To evaluate the repeatability and accuracy of semi-automated software OsiriX in the assessment of cartilage volume in normal knees on 3.0T MR. Methods Thirty right knees of healthy subjects were scanned twice with 3.0T MR using 3D-FLASH sequence with selective water excitation. Cartilage volume of the patellar compartment was determined with a validated open-source software OsiriX and manual segmentation separately by 3 observers using MRI data sets. After calculating the cartilage volumes, the segmentation processing times, the repeatability and volume results were compared between two segmentations. Results ①Compared with the manual segmentation, a time saving of at least 50% for cartilage volume measurement was achieved with OsiriX software segmentation. ②The interobserver repeatability error was 4.88% and 9.82% with OsiriX software segmentation and manual segmentation, respectively;the intraobserver repeatability error of high experienced observer was 0.77% and 1.29%, the interindividual repeatability range were 0.14%-1.11% and 0.52%-1.61%, respectively. The repeatability error of OsiriX software segmentaion was proved to be significantly smaller than manual segmentation (P＜0.05). ③System difference between results obtained with OsiriX software measurement and manual measurement was (-3.80±3.93)% and absolute pairwise difference was (4.68±2.70)%. There was no statistical difference between the volume results measured using two techniques (t=0.92, P=0.36). Conclusion Compared to manual segmentation, cartilage volume measurement with OsiriX semi-automated segmentation is faster and has higher inter- and intraobserver repeatability with relatively fixed standard. This technique may therefore be used for clinical and multi-center trials of large sample.

Objective To investigate the relationship between the peak value of contrast media reaching abdominal aorta andpatients’ factors.Methods Ominpaque 300 mgI/ml 20 ml was injected at a rate of 2.5 ml/s in 108 patients and after 12 s was tracked by test bolus in the abdominal aorta at the level of celiac trunk, then the peak value in the abdominal aorta was achieved by the software dynamic evaluation. Regression analysis and stepwise regression analysis were used to study how the peak value of contrast media reaching abdominal aorta influenced by the patients’ factors including patients’ gender, age, height, weight, heart rate, blood pressure, injection site, peak time, and whether being with heart disease , diabetes mellitus or chemo . Results The peak value of contrast media reaching abdominal aorta was lower in male than that in female averagely, decreased gradually as the patients’ height, weight and peak time increased. The peak value of the injection site in the vein of hand back was lower than that of the cubitus generally and it was not influenced by the patients’ heart rate, blood pressure or whether being with heart disease, diabetes mellitus or chemo. Recommended formula of peak value(HU)=383.8400-Height(cm)?1.0909-Weight(kg)?0.6760+injection site?16.7878-peak time(s)?1.6882.Conclusion The volume of contrast media used in patients needing exam of CT angiography can be adjusted according to the patients’ age, gender, height, weight, injection site and peak time.

Objective To study the technique of multi-slice spiral CT 3D angiography(CTA) and it's clinical appliction.Methods Multi-slice spiral CT angiography(CTA)in 71 cases were analyzed including intracranial vascular CTA 12 cases, thoracic vascular 9 cases, abdominal 23 cases, low extremity 7 cases, carotid 8 cases, renal artery 12 cases. Media contrast were used in 1.5～2ml/kg, the rate of injection were 2.5～3ml/s.Three ways of scan delay time were applied, that was bolus tracking,test bolus and calculating time. Data reconstruction were done with Real time 3D and Fly 3D and MPR in working-station.Results In intracranial CTA, there were intracranial aneurysm 6, AVM 1, normalities 5. On thoracic CTA, lung arterio-venous fistula in 3, lung arterious embolism in 1, thoracic aortic dissection in 3, and normalities in 2 were showed. In abdominal CTA, abdominal aortic aneurysms were 5, dissection were 15, normalities were 3. In renal arteries CTA, left renal artery stenosis were 3, right renal artery stenosis were 2, normalities were 7. In low extremity CTA, artifical vessel was 1, calcification in both femoral artery was 1; aneurysm in both femoral artery was 1,normalities were 4. In carotid artery, calcification in both sides was 1, normalities were 7.The vascular cavity,calcic spots and abdominal aortic dissection could be showed on CTA. Conclusion Multi-slice spiral CT angiography (CTA) can show 3D vascular structure in whole body, CTA is helpful in guiding vascular operation and stent transplantation

Objective To study CT value in diagnosing cystic lymphangioma.Methods There were 14 cases with cystic lymphangioma confirmed by pathology.Male were 6 cases and female were 8 cases,ranged in age from 1～57 years old,CT scans were performed in all patients.CT findings by comparison to operation and pathology were studied.Results Patients were subdivided into head-neck 4 cases; body 3 cases; viscus 7 cases based on the location of the lesions.The density in all lesions were homogeneous except one case with bleeding,the CT value were ?10 HU.The diameter of the lesions were 5～15cm, the margin of the lesions were clear, the adjacent tissue were compressed. The lesions were cycle or similar cycle, the septum in some lesions and the wall of lesions were thin, the septum and wall could be partially enhanced. The histories of disease were 1～10 years, average 4.5?1.6 years. No pain in patients except one case with bleeding were found, 3 cases in body had just a little uncomfortable.Conclusion The location and extent of cystic lymphangioma can be detected by CT and it is of valuable in guiding clinical treatment.

Objective To investigate the suitable injection rate and dose in multi-slice CT perfusion imaging.Methods Randomized block design was adopted in this study.The treatment factor-contrast medium injection rate was classified into 3,4,5,6 and 8 ml/s;thesubjects were divided into 5 blocks grouped by contrast medium injection dose: 0.5,0.75,1,1.25 and 1.5 ml/kg.25 Beagles wererandomly enrolled to undergo cerebral CT perfusion imaging.After post processing,time to peak(TTP) and rise value(RV) were measured in superior sagital venous.Results Injection rate had a significant effect on TTP of superior sagital venous.There was no significant difference among group 5,6 and 8 ml/s.Compared with 8 ml/s,TTP of superior sagital venous was prolonged when injection rate 3,4 ml/swere adopted.Injection dose had a significant effect on RV of superior sagital venous.There was no significant difference among group 1,1.25 and 1.5 ml/kg.In comparison with 1 ml/kg,RV of superior sagital venous was prolonged when injection dose 0.5 and 0.75 ml/kg were adopted.Conclusion The quality of cerebral CT perfusion imaging is well enough even injection rate as low as 5 ml/s or injection dose as few as 1 ml/kg.

Objective To explore the application value of susceptibility weighted imaging(SWI)in measuring brain iron deposition in the diagnosis and the assessment of Parkinson’s disease(PD).Methods Thirty cases with PD underwent head routine magnetic resonance imaging and SWI scanning.The unified PD rating scale(UPDRS)was used to assess the severity of PD.The phase values of substantia nigra (SN),red nucleus(RN),caudate nucleus (CA),globus pallidus(GP)and putamen (PUT)were measured manually on the phase map.The correlation between the phase values of the region of interest(ROI)and the UPDRS scores of PD was analyzed.Results There were no significant differences between the phase values of the less severe body side and those of the more severe body side (SN,P=0.120;RN, P=0.402;CA,P=0.196;GP,P=0.616;PUT,P =0.985).Significant negative correlations were found between the phase values of SN, CA,GP and the UPDRS Ⅲ scores,respectively (SN-UPDRS Ⅲ:r=-0.407,P =0.026;CA-UPDRS Ⅲ:r =-0.424,P =0.02;GP-UPDRS Ⅲ:r=-0.363,P =0.048).Significant negative correlation was found between the phase values of SN and the UPDRSⅤranks (r=-0.373 ,P =0.043 ),while the similar correlation was found between the phase values of CA and the UPDRSⅠ scores (r=-0.367,P =0.046)and the medium negative correlation was found between the phase values of GP and the gait disorder scores of UPDRS Ⅲ(r=-0.41 1,P =0.024).But no correlation was found between the phase values of other ROIs and the UPDRS scores. Conclusion SWI could quantitatively assess the brain iron deposition of the PD patient,which provided reference for clinical diagnosis and assessment of PD.

Objective To identify anatomical characteristics of neurovascular compression associated with trigeminal newralgia(TN).Methods Fifty patients with TN (23 of 50 patients underwent microvascular decompression) and 50 patients without facial pain underwent 3.0 T MRI scanning for analysis of 50 trigeminal nerves ipsilaterai to TN symptoms,50 contralateral to TN symptoms,and 100 in asymptomatic patients.MRI sequences included balanced fast-field echo and 3D MR angiography.Images were fused and reconstructed into virtual cisternoscopy images to determine the degree (severity of compression was defined as follows:1=no compression; 2 =compressed by a vein; 3 =contacted by an artery; 4 =indented by an artery; and 5 =nerve displaced or distorted by an artery) and site of neurovascular compression ( the point of each offending vascular structure:proximal was defined as located in 1/3 length of the cisternal segment of the trigeminal nerve near root entry zone; the place of superior was defined as above the cisternal segment of the trigeminal nerve).Reconstructed MPR images were used to measure nerve length and cross sectional area.The chi-square test was used for all 2 × 2 contingency tables.The t-test was used for dependent samples.The Logistic regression was used for prediction of occurrence of the event of TN.Results Twenty-three of 50 patients with TN underwent microvascular decompression,which confirmed predicted neurovascular relationships in all cases,and 21of 23 patients were pain free after the operation.The incidence of neurovascular compression on asymptomatic nerves ( no.of level 1=79,level 2 =5,level 3 =8,level 4 =8),on nerves contralateral to TN symptoms( no.of level 1=27,level 2 =6,level 3 =9,level 4 =8),and on nerves ipsilateral to TN symptoms(no.of level 1=4,level 2 =12,level 3 =12,level 4 =7,level 5 =15) was 21.0％ (21/100),46.0％ (23/50),and 92.0％ (46/50),respectively.The difference between symptomatic and asymptomatic nerves was significant regarding nerve distortion ( level 4 and 5,x2 =27.0,P ＜ 0.01),the point of compression ( no.of proximal of symptomatic nerves =32,not proximal of symptomatic nerves =14,proximal of asymptomatic nerves =4,not proximal of asymptomatic nerves =17,x2 =14.8,P ＜ 0.01),the place of vascular compression ( no.of superior of symptomatic nerves =36,not superior of symptomatic nerves =10,superior of asymptomatic nerves =5,not superior of asymptomatic nerves =16,x2 =18.0,P ＜0.01) and the mean cross-sectional area of the CPA cistern [ ipsilateral:( 183.9 + 52.5 ) mm2,contralateral:( 217.8 + 58.8 )mm2,t =- 3.04,P ＜ 0.01].Decreased nerve size was observed in patients with TN [ the section area of ipsilateral nerve ( 6.3 ±1.3) mm2,contralateral (7.7+1.6) mm2,t =-4.80,P ＜0.01; length of ipsilateral nerve:(8.0 ±1.9) mm,contralateral:(9.0 + 2.0) mm,t =- 2.64,P ＜ 0.05 ].Conclusions Trigeminal neurovascular compression can occur in asymptomatic patients,but is more severe,more proximal,more superior and with smaller size of cross-sectional area of the CPA cistern in patients with TN.This information may help identify patients who are likely to benefit from microvascular decompression.

Objective To observe the lumbosacral plexus nerves by diffusion tensor tractography (DTT) and quantitatively evaluate them by using diffusion tensor imaging (DTI) in healthy volunteers.Methods A total of 60 healthy volunteers (30 males and 30 females) underwent DTI scanning.Mean FA values of the lumbosacral plexus nerves (both sides of lumbar roots L3 to S1,proximal and distal to the lumbar foraminal zone) were quantified.Differences among various segments of lumbar nerve roots were compared with ANOVA test and SNK test.Differences between two sides of the lumbar nerve roots at the same lumbar segment were compared with paired-samples t test.Differences between the proximal and the distal nerve to the the lumbar foraminal zone at the same lumbar segment were compared with paired-samples t test.The lumbosacral plexus nerve was visualized with tractography.Results (1) The lumbosacral plexus nerve was clearly visualized with tractography.(2) Mean FA values of the lumbar nerve roots L3 to S1 were as followings:proximal to the left lumbar foraminal zone 0.202 ± 0.021,0.201 ± 0.026,0.201 ± 0.027,0.191 ±0.016,distal to the left lumbar foraminal zone 0.222 ± 0.034,0.250 ± 0.028,0.203 ± 0.026,0.183 ± 0.020,proximal to the right lumbar foraminal zone 0.200 ± 0.023,0.202 ± 0.023,0.205 ± 0.027,0.191 ±0.017,distal to the right lumbar foraminal zone 0.225 ±0.032,0.247 ±0.027,0.205 ± 0.033,0.183 ±0.021.Mean FA values were significantly different between the proximal nerve to the distal nerve in lumbar nerve roots L3,L4,S1 (t =-9.114-2.366,P ＜ 0.05),but not significantly different in L5 (P ＞ 0.05).Differences were not found between the right and left side nerves at the same lumbar segment (P ＞ 0.05).(3) The whole length of the lumbar roots nerve L3 to S1 can be visualized clearly by using DTT.Conclusions Diffusion tensor imaging and tractography can show and provide quantitative information of human lumbosacral plexus nerves.DTI is a potential tool for the diagnosis of lumbosacral plexus nerve disease.