Observation on impact of activity on knee meniscus with T1 rho and T2 mapping sequences / 中国医学影像技术

Objective To observe the impact of walking,running and stair activity on knee meniscus with T1 rho and T2 mapping sequences.Methods Twenty-three participants immediately after 30 minutes of rest,walking,running and stair activity underwent MRI scanning of the right knee,respectively.The 30 minutes rest was conducted before every physical activity.The physical activities were performed randomly to every participant in the morning every other week.T1 rho andT2 values of the meniscus in different physiological activities were estimated.Results T1 rho and T2 values reduced after physiological activities in posterior horn,body of medial meniscus and body of lateral meniscus compared with those of rest state (all P＜50.05).Compared with rest,reduction rate of T1 rho and T2 values of medial meniscus after different physiological activities reduced in the following order:Posterior horn ＞ body ＞ anterior horn,while those of lateral meniscus reduced in the following order:Body ＞ posterior horn ＞ anterior horn.Conclusion T1 rho and T2 mapping sequences are sensitive technologies to monitor the impacts of different activities on knee meniscus.

Analysis of microstructure and blood perfusion in thalamus and basal ganglia in patients with untreated depressive disorder / 中国医学影像技术

Objective To investigate the changes of microstructure and blood perfusion of thalamus and basal ganglia in patients with untreated depressive disorder using diffusion kurtosis imaging (DKI) and three-dimensional arterial spin labeling (3D ASL) perfusion imaging.Methods Totally 21 untreated patients with depressive disorder (disease group) and 32 healthy volunteers (control group) underwent DKI,3D ASL and routine MR scanning were enrolled.DKI parameters (mean kurtosis [MK],axial kurtosis [Ka],radial kurtosis [Kr],fractional anisotropy [FA],mean diffusivity [MD],axial diffusivity [Da] and radial diffusivity [Dr]) and 3D ASL parameters (cerebral blood flow [CBF]) of bilateral heads of caudate nucleus,thalamus and putamens were measured and compared between the 2 groups.Results Compared with control group,Ka of left caudate head in disease group was significantly higher,while Kr was significantly lower (both P＜ 0.05).Ka of right putamens in disease group was significantly higher than that in control group (P＜0.05).Compared with control group,CBF of left caudate head and bilateral putamens decreased significantly in disease group (all P＜0.05).Conclusion Untreated depressed patients show abnormal DKI parameters and blood perfusion in basal ganglia,which indicating that microstructure integrity is impaired and blood perfusion decreases.The abnormalities in basal ganglia microstructure and blood perfusion may serve as one of the neuroimaging features of depressive disorders.

T1ρmagnetic resonance imaging for detection of early articular cartilage degeneration in knees of rabbit model treatment by Epimedium / 实用放射学杂志

Objective To explore the role of MRI(T1ρ)in the early osteoarthritis,curative efficacy monitoring and speculated that the mechanism of curative effect.Methods (1)(early OA model)A total of 28 New Zealand white rabbits were randomly divided into A,B,C three groups.group A(treatment)and B(control)were both for 1 1 rabbits,and 6 rabbits were considered as blank control group(group C).0.5 mL 1.6% papain was injected into the right knee joint cavity both group A and B according to three times (1,4,7 days).The equivalent dilution was injected into the left knee joint cavity simultaneously.3 weeks after the first injection,and T2 WI,3D-FS-SPGR,and T1ρ mapping in sagittal plain were scanned for three groups.Randomly selected two models pathology test in the group A and B,confirm early OA model is established.(2)(treat models)Then give epimedium lavage to group A two month.The equivalent sterile saline lavage to group B.A certain time (T0 = 0,T1 = 1 mon,T2 = 2 mon)after treated do MR scanned for group A and B.Analysis of the image.T1ρvalues and the cartilage thickness in bilateral femoral condyle cartilage were measured by post-processing software.The all femurs were pathological examined.T1ρvalues and the cartilage thickness were statistic analysis. Results (1)Articular cavity injection of papain can successfully establish early osteoarthritis rabbit model which pathology has been confirmed.T1ρvalues of the experimental (group A,B)were significant higher than of the control side(P0.05).(2)T1ρvalues of the Epimedium treat model (right side)were significant lower than of the pre-treatment that of the preintervention (P 0.05).Conclusion (1)T1ρvalues of the early and advanced stage of OA had increased in various degree,and the values related cartilage matrix composition.(2 )Single herb Epimedium has effective to treat early stages osteoarthritis in knee joint.Spec-ulated that the possible mechanism for treatment common channel in the development of OA,which inhibition protease formation and promote proteoglycan secretion.

Applied Value of Diffusion Tensor Imaging in Early Evaluation of Prognosis of Hypoxic-Ischemic Encephalopathy in New Infants / 实用放射学杂志

Objective To study the value of diffusion tensor imaging(DTI) in early assessment of prognosis of hypoxic-ischemicencephalopathy(HIE) in new infants. Methods 96 cases of full term infants with HIE underwent DTI examinations at 0～12 days and 6～36 months. Based on clinical diagnostic criteria, 96 cases were divided into three groups: mild, moderate and severe HIE groups. Fractional anisotropy(FA) values in the corpus callosum splenium and the posterior limb of internal capsules were measured. Results (1) Varying degrees of FA groups was significantly different from the same site, increased linearly with time,but the magni-tude of change was different;(2)When FA value of corpus callosum splenium in the cut-off point was ≥0.437,the sensitivity(SE) was 83.8% , the specificity(SP) was 18.6% , ROC area under the curve was 0.903 , 95% confidence interval was from 0.846 to 0.961,standard error was 0.029;when FA value of posterior limb of internal capsule in the cut-off point ≥0.391,SE was 86.5%, SP was 11.9% ,ROC area under the curve was 0.940,95% confidence interval was from 0.898 to 0.984,standard error was 0.022. Conclusion MR DTI examination is of significant value in evaluating early the prognosis of HIE in infants.

Comparison between MR relaxometry techniques and dual-energy X-ray absorptiometry in evaluation of osteoporotic postmenopausal rats / 中华放射学杂志

Objective To evaluate MR relaxometry techniques and dual-energy X-ray absorptiometry (DXA) for the diagnosis of osteoporotic diseases in rats. Methods Thirty 3-month-old female rats were randomly divided (using completely randomized grouping method) into two groups (each contained 15 rats). Animals in group A without osteoporotic castration were included as normal controls, whereas osteoporotic castration was created in each animal in group B. Three parameters (BMC, BMD, Hbmdl)was measured for both groups by DXA at two time points, one immediately before the castration and another at the 12 th week after the castration. Then animals from the control group and the osteoporotic group went through the following three diagnostic procedures using a 1.5 T MR system: (1) A fast multi echo gradient echo (MEGRE) pulse train sequence with different inter-echo intervals (1000, 500, 400, 300, 200, 100) to obtain the T_2~* value. (2) A multi-echo fast spin echo sequence to obtain the T_2map. (3) A conventional spin-echo (CSE) sequence to obtain the T_1map. The statistical difference between group A and group B was tested by t-test to analyze parameters. And, the most significant parameter for diagnosis ofosteoporotic diseases was picked out from all parameters by Fisher Sequential diseriminant analysis. At the end of experiments, animals were killed and histopathological examination was performed on the femurs of animals from both control and osteoporotic groups. Results (1) Histopathological examination confirmed the presence of osteoperosis in all animals in group B. (2) BMD was picked out from 3 DXA parameters (BMC,BMD,Hbmdl) by fisher stepwise discriminant analysis, and its discriminant rates was 87.6%. (3) All 2-sample t-test results(t=6.20, 4.79, 5.18, 5.22, 5.59, 4.37, 6.14, 5.12, 5.09, 4.99, 5.57, 4.84, 4.07, 2.98, 6.75 individually) for MR relaxometry parameters(T_2~* 1000,R_2~* 1000,T_2~* 500,R-2~* 500,T_2~* 400,R_2~* 400,T_2~* 300,R_2~* 300,T_2~* 200, R_2~* 200, T_2~* 100, R_2~* 100, T_2map, R_2map, T_1map) showed statistically significant differences between groups A and B (P=0.01 for T_2~* map, P=0.00 for all other parameters) except the R_2map(P=0.07). (4) Using fisher stepwise discriminafion method in the analysis of 14 parameters of MR relaxometry techniques and 3 parameters of dual X-ray absorptiometry(T_2~* 1000,T_2~* 500,T_2~* 400,T_2~* 300,T_2~* 200,T_2~* 100,T_2map, R_2~* 1000, R_2~* 500, R_2~* 400, R_2~* 300, R_2~* 2OO, R_2~* 100,T_1map,BMC,BMD,Hbmdl), we found that the most significant difference was from the T_2map and T_1map. Conclusions The MR relaxometry parameter-T_2map in the present study is shown to be appropriate parameter for the diagnosis of osteoperotie diseases, and stability of magnetic field plays an important role in this process. It would be the optimal method to make a diagnosis of osteoporotic diseases with both MR relaxometry and DXA technological means.

The preliminary diffuse tensor MR imaging study of correlation of white matter anisotropy with age in normal adults / 中华老年医学杂志

0.05). Conclusions DTI is valuable in assessing the directionality and density of white matter and can reflect the age-related physiological changes of white matter in vivo non- invasively.

The Posterior Contour Sign of the Lumbar Intervertebral Disc----A Sign to Show the Posterior Border of Disc in Plain Film / 实用放射学杂志

Objective:To eveluate and study the anatomic basis of the posterior contour sign of lumbar intervertebral disc.Methods:The most protruding length of the soft tissue mass behind intervertebral spase on lumbar plain film were measured in 100 cases and compared with CT or MR findings.Results:41 posterior contour sign of the interlumbar disc were fined in 39 cases,of which there were 25 in L4/5(61.0%),15 in L3/4(15.6%)and 1 in L2/3(2.4%).The protruding was less than 0.2 cm in 26 and larger than 0.2 cm in 15,there were 10 lumbar disc protruding confirmed by CT or MR ,7 of which the pesterior contour ≥0.2 cm,and 3＞0.3 cm,none was ≤0.2 cm.Conclusion:The adipose tissue in the posterior border of lumbar body and disc was the anatomic basis of the sign,and it was an importent sign for diagnosing of lumbar disc hernia on plain film.

The application of diffusion weighted imaging and apparent diffusion coefficients mapping in monitoring the development of cerebral infarction / 中华放射学杂志

Objective To study the roles of isotropic diffusion weighted imaging and apparent diffusion coefficients (ADC) mapping in diagnosing cerebral infarction, monitoring the development of cerebral infarction and defining the infarction stages.Methods 86 work-ups in 70 patients with cerebral infarction (8 hyperacute, 13 acute, 32 subacute, 11 steady, and 22 chronic) were imaged with both conventional MRI and single-shot echo-planar isotropic diffusion weighted imaging.The change of the infarct lesion in DWI and T_2WI was also analyzed.The average ADC, relative ADC (rADC), and the ADC from center to periphery of the lesion were calculated.Results 8 hyperacute cerebral ischemic regions were revealed at DWI and ADC mapping.Hyperacute and acute infarcts appeared as areas of hyperintensity on DWI, and their average ADC was significantly depressed compared with that of homologous contralateral tissue [(0.698?0.104) ?10 -3 mm 2/s versus (0.990?0.161)?10 -3 mm 2/s; t=-14.372, P

Normal Articular Cartilage of the Adult Knee:Evaluated with Multiple MR Sequences Imaging / 实用放射学杂志

Objective To compare with the advantage or shortage of several scan series in imaging of normal articular cartilage in knee.The MR manifestation were observed and thickness of different location of cartilage in knee in different series were calulated.Methods The knees of 30 healthy volunteers were imaged with five different MR imaging sequences including T 1-weighted,proton density-weighted,T 2-weighted FSE,STIR and 3D-FS-SPGR.The value of CNR were determined for cartilage versus a saline fluid phantom,marrow fat,and muscle.The MR 2D and 3D manifestation were observed and thickness of different location of cartilage in knee in different series were calculated.Results The value of CNR of 3D-FS-SPGR for cartilage versus a saline fluid phantom,marrow fat,and muscle were compared with other sequences and were significantly different.The values of cartilage thickness with 3D-FS-SPGR were more than those with other series.The mulplaner appearance was observed.There was five-plane manifestation when cartilage thickness was more than 4 mm.The value of cartilage thickness of male and female were 2.63 mm and 2.52 mm,respectively.Conclusion 3D-FS-SPGR sequences have significant advantage compared with other series in imaging normal articular cartilage of knee.The cartilage is show clearly than other sequences.The value of cartilage thickness with 3D-FS-SPGR is more accurate.Moreover it can also provide much information adding to 3D construction of cartilage.

The Evaluation of Monitoring Devices in the Intensive Care Unit with Bedside Chest Computed Radiography / 实用放射学杂志

Objective To assess the contribution of the portable chest computed radiography (CR) in evaluation of monitoring devices of the patients in the intensive care unit (ICU). Methods One hundred and sixty-two cases with 387 chest radiographs in the ICU were analysed retrospectively. The location of the catheters of monitoring devices and complications were observed.Results The malposition of the catheters was detected in 47 cases(16.9%),including the endotracheal (ET) tubes too deep at the position, the central venous catheters placed into the internal jugular veins,and the position of the thoracic drain tubes to be deep not enough causing the drain to fall.The complications after operation of monitoring devices were not common,including pneumothorax caused by ventilatory assistance,atelectasis and pneumonia caused by malposition of the ET tubes,totally in 11 cases.10 cases with cardiopulmonary abnormalities were discovered accidentally in all 162 cases(6.2%) when evaluation of monitoring devices.Conclusion Bedside chest CR not only can show the catheter position and the complications of the monitoring devices ,but also the cardiopulmonary abnormalities of patients in the ICU.

Bedside Chest Radiography in the Intensive Care Unit / 实用放射学杂志

Objective To evaluate the applied value of bedside chest radiography in the intensive care unit ( ICU ) . Methods One hundred and ninety-three cases with 507 chest radiographs (CXRs) in the ICU were analysed retrospectively. The appearances of cardiopulmonary abnormalities were analysed.Results 97.4% of the CXRs were satisfied for diagnosis. 83.9% of the CXRs showed cardiopulmonary abnormalities, including atelectasis, pneumonia, pulmonary edema, ARDS, pneumothorax, mediastinal and subcataneous emphysema,pleural effusion,pericardial effusion and pulmonary thromboembolism, and 6.2% out of these positive cases was discovered accidentally. The chest radiograph has moderate accuracy (77.9%) in visualizing cardiopulmonary abnormalities at the initial CXR including atelectasis,pneumonia,pulmonary edema and pleural effusion. Misdiagnosis occurred mainly on the patients with a small quantity of pneumothorax and pulmonary thromboembolism. About one-third cases of cardiogenic edema and ARDS were indistinguishable.Conclusion Bedside chest radiographs are of significant value for the patients in the ICU.

Preliminary Study of Cerebrovascular Capacity with MR Perfusion-Weighted Imaging after Administration of Acetazolamide / 实用放射学杂志

Objective To study the value of MR perfusion-weighted imaging(PWI)after administration of acetazolamide(ACZ)in evaluating the cerebrovascular capacity.Methods MR perfusion-weighted imaging were performed before and after ACZ administeredorally in 7 cases with cerebral infarction.The values of rCBV and rMTT were analysed and the cerebrovascular capacity were evaluated.Results The prolonged rMTT was found in rMTT map before and after ACZ in all cases.Only 5 subjects were abnormal at rCBV map visually.rMTT was increased at the abnormal region on rMTT map.The abnormal regions at rCBV maps included both rCBV increased or decreased.The abnormal region was larger at rMTT map than that at rCBV map.Conclusion MR perfusion-weighted imaging with ACZ test has significant value in assessing the cerebrovascular capacity.

Neonatal Hypoxic-Ischemic Encephalopathy:Follow-up Value with MRI / 实用放射学杂志

Objective To study the follow-up value of MRI in the sequela hypoxic-ischemic encephalopathy(HIE).Methods MRI features of HIE in 81 neonates were analyzed retrospectively,every child had two cranial MRI scans,the first scan at the end of the newborn stage,the second scan at 4 months to 4 years.There were 66 full-term neonates and 15 preterm neonates.Results Of 81 cases,79 cases were abnormal on second MRI examination,including myelinogenetic abnormal in 59 cases(72.8%),external hydrocephalus(EH) in 53 cases(65.4%),brain malacia in 26 cases(32.1%),cerebaral atrophy in 25 cases(30.1%),white matter decrease in 24 cases(29.6%) and dysplasia of corpus callosum in 9 cases(11.1%).EH(26/35cases) and myelinogenetic abnormal(16/35 cases) in mild HIE group,brain malacia(12/29 cases) in moderate HIE group,cerebaral atrophy(16/17 cases) and white matter decrease(15 /17 cases)in severe HIE group were often seen.Conclusion MRI findings can reflect the pathological changes of sequela of HIE,and provide objective basis for diagnosis and assessment of prognosis.

Imaging diagnosis of the articular cartilage disorders / 中华放射学杂志

Objective To evaluate the diagnosis and differential diagnosis among the chronic osteoarthritis, rheumatoid arthritis and other chronic cartilage lesions on the plain films and MR images. Methods Eighty-nine cases, including 115 joints, underwent plain film and MRI examination, and enhanced MRI scan was performed on 32 of them, including 44 joints. MRI scan sequences consisted of T 1WI, T 2WI+PDWI, STIR, and 3D FS SPGR. There were 90 knee joints in this group and each of the articular cartilage was divided into four parts: patella, femoral medial condyle, femoral lateral condyle, and tibia facet on MR images. The cartilage disorders were classified according to the outerbridge method. In addition, 61 cases including 75 joints were observed as a control group on the plain films and MR images. Results 115 cartilage lesions were found on MR images, in which thinness of the cartilage (58 cases, 50 4%), bone changes under the cartilage (22 cases, 19.7%), medullar edema (22 cases, 19.7%), and synovial hyperplasia (52 cases, 45.2%) were seen. The patella cartilage was the most likely affected part (81/90, 90%). So the patellar cartilage lesions were divided as group 1 (grade Ⅰ-Ⅱ) and group 2 (grade Ⅲ-Ⅳ) on MR images, which were compared with the plain film signs. The narrowing of the joint space and saccules under the articular surface were statistically significant with each other, and ? 2 values were 9.349 and 9.885, respectively (P=0.002). Conclusion No constant signs could be seen on the plain films with grade Ⅰ-Ⅱ cartilage disorders. While the narrowing joint space and saccules under the joint surface could be seen on them with grade Ⅲ-Ⅳ cartilage disorders, which were mainly correlated with the cartilage disorders and bone changes under the articular cartilages. A combination of the plain films and MR images is the best imaging method for examining the joints and joint cartilages. Enhanced MRI scan is very helpful on the diagnosis and differential diagnosis of the synovial lesions.

The Application of Fat-suppressed Spoiled Gradient-Echo (3D-FS-SPGR) Sequence in Association withThree-Dimensional Reconstruction in Cartilage Disorder of Knee / 实用放射学杂志

Objective To evaluate the clinical value of 3D-FS-SPGR and 3D-reconstructional technique in detecting the lesion of articular cartilage of knee.Methods Fifty eight knees with OA(42 cases)or trauma (9 cases) in 54 cases (12 cases were confirmed by operation) were imaged with eight different MR imaging sequences including T 1-weighted,proton density-weighted,T 2-weighted FSE,STIR,3D-FS-SPGR,2D-FS-SPGR,3D-SPGR and 3D-FS-GRE.The classification and three-dimensional reconstruction of cartilage in four locations of knee were performed on different MR sequences.The detecting rate of cartilage lesion were calculated.The results in partly cases were analysed compared to operation. Results The detecting rate was different on each sequence as follow:T 1WI,GRE,STIR,PDWI,T 2WI and SPGR were 8.91%,16.36%,19.32%,19.57%,21.36% and 24.09% respectively (? 2=23.523,?

The application of DWI and ADC mapping in acute cerebral infarction and basis of pathophysiology / 中国病理生理杂志

AIM: To study the roles of isotropic diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)mapping in diagnosing early cerebral infarction.METHODS: 21 patients with cerebral in farction (8hyperacute,13 acute)were imaged with both conventional MRI and single-shot echo-planar isotropic diffusion weighted imaging.Among them 12 patients had CT scanning simultaneously within 24 hours after onset.The positive rate of early infarction was comparted on CT,T 2WI and DEI.The change of the infarct lesion in DWI and T 2WI was also analysed.The average ADC,relative ADC(rADC)and the ADC from center to periphery of the lesion were calculated.RESULTS: 8 hyperacute cerebral ischemic regions were revealed at DWI and ADC mapping,but CT and conventional MR were not.Hyperacute and acute infarcts appeared as areas of hyperintensity on DWI,and their average ADC was significantly depressed comparted with homologous contralateral tissue (0 698?0 104 ?s 0 990?0 161?10 -3 mm 2/s; P