Moderated mediation analysis for symptoms of attention deficit/hyperactivity disorder with the symptoms of anxiety in children / 中国当代儿科杂志

OBJECTIVE@#To study the moderated mediation for attention deficit/hyperactivity disorder (ADHD) with the symptoms of anxiety in children.@*METHODS@#A total of 12 271 students were included with an average age of 8.9±1.9 years, including 6 743 male students and 5 508 female students, and 20 students with missing data on gender. Child psychological trauma questionnaires (parents version) and Conners questionnaires (parent version) were completed by the parents of primary school students. The data was studied by univariate analysis, multivariate analysis and moderated mediation analysis.@*RESULTS@#The results of the univariate analysis showed that in all subjects, boys, and girls, the scores of hyperactivity index and childhood trauma were positively correlated with the score of anxiety (P<0.01), and ADHD and childhood trauma positively predicted anxiety disorder (P<0.001). The results of the multivariate analysis showed that in all subjects, boys, and girls, the scores of hyperactivity index (ADHD symptoms) and childhood trauma positively predicted the score of anxiety (P<0.001), and both ADHD and childhood trauma positively predicted anxiety disorder (P<0.001). The results of the moderated mediation analysis showed that childhood trauma was a mediating factor for the relationship between hyperactivity index and anxiety index in boys and girls (P<0.05), and sex moderated the relationship between hyperactivity index and anxiety index (P<0.001).@*CONCLUSIONS@#ADHD symptoms/ADHD are closely associated with anxiety symptoms/anxiety disorder. Childhood trauma exerts a mediating effect on the relationship between ADHD symptoms and anxiety symptoms, and sex moderates the relationship between ADHD symptoms and anxiety symptoms.

Sleep fragmentation as an important clinical characteristic of sleep disorders in Parkinson’s disease: a preliminary study / 中华医学杂志(英文版)

Background@#Sleep disorders are one of the earliest non-motor symptoms of Parkinson’s disease (PD). Sleep disorders could, therefore, have value for recognition and diagnosis in PD. However, no unified classification and diagnostic criteria exist to evaluate sleep disorders by polysomnography (PSG). Utilizing PSG to monitor sleep processes of patients with PD and analyze sleep disorder characteristics and their relationship with demographic parameters could aid in bridging this gap. This preliminary study aimed to evaluate the clinical characteristic of sleep disorders in PD using PSG.@*Methods@#PSG was used to evaluate sleep disorders in 27 patients with PD and 20 healthy volunteers between August 2015 and July 2018 in Fujian Medical University Union Hospital. Total sleep time (TST), sleep efficiency (SE), total wake time, and other parameters were compared between the two groups. Finally, the correlation between sleep disorders and age, disease duration, Unified Parkinson’s Disease Rating Scale-III scores, Hoehn-Yahr stage, and levodopa dose were analyzed. The main statistical methods included Chi-square test, two independent samples t test, Fisher exact test, and Pearson correlation.@*Results@#Sleep fragmentation in the PD group was significantly increased (74.1%) while difficulty falling asleep and early awakening were not, as compared to healthy controls. No significant differences were found in time in bed, sleep latency (SL), non-rapid eye movement (NREM) stage 1 (N1), N1%, N2, N2%, N3%, and NREM% between PD and control groups; but TST (327.96 ± 105.26 min vs. 414.67 ± 78.31 min, P = 0.003), SE (63.26% ± 14.83% vs. 76.8% ± 11.57%, P = 0.001), R N3 (20.00 [39.00] min vs. 61.50 [48.87] min, P = 0.001), NREM (262.59 ± 91.20 min vs. 337.17 ± 63.47 min, P = 0.003), rapid-eyemovement (REM) (32.50 [33.00] min vs. 85.25 [32.12] min, P < 0.001), REM% (9.56 ± 6.01 vs. 15.50 ± 4.81, P = 0.001), REM sleep latency (157.89 ± 99.04 min vs. 103.47 ± 71.70 min, P = 0.034) were significantly reduced in PD group.@*Conclusion@#This preliminary study supported that sleep fragmentation was an important clinical characteristic of sleep disorders in PD. Whether sleep fragmentation is a potential quantifiable marker in PD needs to be further investigated in the future study.

Sleep fragmentation as an important clinical characteristic of sleep disorders in Parkinson's disease: a preliminary study / 中华医学杂志(英文版)

BACKGROUND@#Sleep disorders are one of the earliest non-motor symptoms of Parkinson's disease (PD). Sleep disorders could, therefore, have value for recognition and diagnosis in PD. However, no unified classification and diagnostic criteria exist to evaluate sleep disorders by polysomnography (PSG). Utilizing PSG to monitor sleep processes of patients with PD and analyze sleep disorder characteristics and their relationship with demographic parameters could aid in bridging this gap. This preliminary study aimed to evaluate the clinical characteristic of sleep disorders in PD using PSG.@*METHODS@#PSG was used to evaluate sleep disorders in 27 patients with PD and 20 healthy volunteers between August 2015 and July 2018 in Fujian Medical University Union Hospital. Total sleep time (TST), sleep efficiency (SE), total wake time, and other parameters were compared between the two groups. Finally, the correlation between sleep disorders and age, disease duration, Unified Parkinson's Disease Rating Scale-III scores, Hoehn-Yahr stage, and levodopa dose were analyzed. The main statistical methods included Chi-square test, two independent samples t test, Fisher exact test, and Pearson correlation.@*RESULTS@#Sleep fragmentation in the PD group was significantly increased (74.1%) while difficulty falling asleep and early awakening were not, as compared to healthy controls. No significant differences were found in time in bed, sleep latency (SL), non-rapid eye movement (NREM) stage 1 (N1), N1%, N2, N2%, N3%, and NREM% between PD and control groups; but TST (327.96 ± 105.26 min vs. 414.67 ± 78.31 min, P = 0.003), SE (63.26% ± 14.83% vs. 76.8% ± 11.57%, P = 0.001), R N3 (20.00 [39.00] min vs. 61.50 [48.87] min, P = 0.001), NREM (262.59 ± 91.20 min vs. 337.17 ± 63.47 min, P = 0.003), rapid-eye-movement (REM) (32.50 [33.00] min vs. 85.25 [32.12] min, P < 0.001), REM% (9.56 ± 6.01 vs. 15.50 ± 4.81, P = 0.001), REM sleep latency (157.89 ± 99.04 min vs. 103.47 ± 71.70 min, P = 0.034) were significantly reduced in PD group.@*CONCLUSION@#This preliminary study supported that sleep fragmentation was an important clinical characteristic of sleep disorders in PD. Whether sleep fragmentation is a potential quantifiable marker in PD needs to be further investigated in the future study.

Polymorphism of XRCC1 and chromosome damage in workers occupationally exposed to benzene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between the polymorphisms of DNA repair gene (XRCC1 194, 280 and 399) and the chromosomal damage induced by benzene.</p><p><b>METHODS</b>The chromosomal damage of the peripheral lymphocytes in 459 workers occupationally exposed to benzene and 88 non-exposed controls were detected with cytokinesis-block micronucleus (CBMN) assay. PCR-RFLP technique was used to measure polymorphisms in XRCC1 194, 280 and 399.</p><p><b>RESULTS</b>It was found that the MN frequency (2.12‰ ± 1.88‰) of the exposed group was significantly higher than that (1.19‰ ± 1.68‰) of the control group (P < 0.05), in the exposed group, the MN frequency (3.00‰ ± 2.76‰) of older workers (> 35 years) was significantly higher than that (2.02‰ ± 1.71‰) of younger workers (≤ 35 years) (P < 0.05). The effect of genetic polymorphisms of XRCC1 on CBMN was not found. The haplotypes AAA/BAA, AAB/AAB, ABA/ABA, ABB/ABB could associated with the increased frequencies of total micronucleus (P < 0.05).</p><p><b>CONCLUSION</b>Benzene exposure could result in chromosome damage. Age of workers and diplotypes of XRCC1 could associated with chromosomal damage induced by benzene.</p>

CT features of colloid carcinomas of the pancreas / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Colloid carcinomas of the pancreas have better prognosis than ordinary ductal adenocarcinoma, and preoperative distinction of colloid carcinoma from other pancreatic tumors is valuable for patient therapeutic planning and prognosis assessment. However, data about CT features of colloid carcinoma are very limited. This study aimed to investigate the CT features of this tumor.</p><p><b>METHODS</b>Institutional review board approval was obtained for this study. Seven patients with pathologically proven colloid carcinoma of the pancreas were included. Unenhanced and dynamic enhanced CT was performed in all the patients. CT features were analyzed retrospectively and correlations with pathological findings were evaluated.</p><p><b>RESULTS</b>Mean age of the patients was 59.8 years (41 - 76 years). Five tumors were located in the pancreatic head, and the other two in body and tail respectively. The maximum mean diameter of the tumors on axial scanning was 3.9 cm (3.0 - 6.7 cm). Tumors were round (n = 5) and lobular (n = 2). Tumors appeared slight hyp-attenuation on unenhanced CT, and peripheral and internal meshlike progressive delayed enhancement with great percent of cystic areas on enhanced CT. Calcification and gas in the tumor was seen in one patient whose duodenum was invaded by the tumor.</p><p><b>CONCLUSIONS</b>Colloid carcinomas of the pancreas appear as round or labular masses with great percent of cystic areas and slight hyp-attenuation on unenhanced CT and peripheral and internal meshlike progressive delayed enhancement on enhanced CT.</p>

Magnetic resonance imaging of artificial lumbar disks: safety and metal artifacts / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study was to investigate the safety of two types of commercially available lumbar artificial discs (CHARITE and PRODISC-L) during a magnetic resonance imaging (MRI) procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences.</p><p><b>METHODS</b>A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency (RF) magnetic field was evaluated by using "worst-case" imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc (used as a control) were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences.</p><p><b>RESULTS</b>The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC-L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6 degrees C, respectively. The size of metal artifacts on images of TSE (T1/T2 -weighted), STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE (T1-weighted) sequences.</p><p><b>CONCLUSIONS</b>The CHARITE and the PRODISC-L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5 T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located (e.g., vertebral canal at affected segment).</p>

In vivo proton magnetic resonance spectroscopy of hepatocellular carcinoma and cholangiocarcinoma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the value of in vivo proton magnetic resonance spectroscopy (1H MRS) in the assessment of hepatocellular carcinoma (HCC) and cholangiocarcinoma.</p><p><b>METHODS</b>1H MRS was performed in normal volunteers and in patients with pathologically confirmed HCC and cholangiocarcinomas using a whole-body 1.5-T scanner. The choline-to-lipid ratios were measured by dividing the peak area of choline at 3.2 ppm and lipid at 1.3 ppm.</p><p><b>RESULTS</b>The ratio of choline-to-lipid for normal liver, cholangiocarcinomas, and HCC were 0.07 +/- 0.04, 0.11 +/- 0.06, and 0.52 +/- 0.15, respectively. The ratio of choline-to-lipid was significantly higher in HCC compared than those in cholangiocarcinomas or normal livers (P < 0.05). However, it was not significantly different between cholangiocarcinomas and normal livers (P > 0.05).</p><p><b>CONCLUSION</b>In vivo 1H MRS can reflect the pathological changes of HCC and cholangiocarcinomas at metabolic level and thus is useful in the diagnosis of these two cancers.</p>

Magnaporthe oryzae MTP1 gene encodes a type III transmembrane protein involved in conidiation and conidial germination / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp1 protein is 520 amino acids long and is comparable to the Ytp1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtp1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Deltamtp1 mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.

A simple and effective method for total RNA isolation of appressoria in Magnaporthe oryzae / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Appressorium formation is an important event in establishing a successful interaction between the rice blast fungus, Magnaporthe oryzae, and its host plant, rice. An understanding of molecular events occurring in appressorium differentiation will give new strategies to control rice blast. A quick and reliable method to extract total RNA from appressorium is essential for studying gene expression during appressorium formation and its mechanism. We found that duplicate film is an efficient substratum for appressorium formation, even when inoculated with high density conidia. When inoculated with conidia at 1x10(6) ml(-1), the percentages of conidium germination and appressorium formation were (97.98+/-0.67)% and (97.88+/-0.45)%, respectively. We applied Trizol before appressorium collection for total RNA isolation, and as much as 113.6 microg total RNA was isolated from the mature appressoria at 24 h after inoculation. Functional analysis of two genes, MNH6 and MgATG1, isolated from the cDNA subtractive library, revealed that the quantity of RNA was good enough to construct a cDNA (complementary DNA) library or a cDNA subtractive library. This method may be also applicable for the appressorium RNA isolation of other pathogenic fungi in which conidia differentiate into appressoria in the early stages of host infection.

Therapeutic effects of aspiration with a directional soft tube and conservative treatment on mild hemorrhage in the basal ganglion / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the therapeutic effects of aspiration via a directional soft tube and conservative treatment in patients with mild hemorrhage in the basal ganglion.</p><p><b>METHODS</b>Seventy-five patients with mild cerebral hemorrhage (10~30 ml) were randomly divided into two groups for aspiration treatment with minimally invasive directional soft tube placement (minimally invasive group, n=36) and conservative treatment (medication group, n=39). The patients in the two groups had comparable mean GCS scores of 11-15 on admission. The clinical outcomes of the patients were compared between the two groups.</p><p><b>RESULTS</b>In the minimally invasive group, complete removal or absorption of the hematoma occurred within an average of 3.8 days, significantly shortened in comparison with the 24 days in the medication group. The short-term (1 month) follow-up of the patients showed good neurological recovery in 58% of the patients in the minimally invasive group, significantly greater than the rate of 29% in the medication group; 6 months after the treatment, good neurological recovery was achieved in 50% of the patients in the minimally invasive group, but only 16% in the medication. No death occurred in the minimally invasive group, and 2 patients died in the medication group. The cost of hospitalization averaged 5136.3 Yuan in the minimally invasive group and 11843.6 Yuan in the medication group.</p><p><b>CONCLUSION</b>Compared with conservative treatment, the minimally invasive treatment with soft tube placement can significantly shorten the hospital stay, promote neurological function recovery, lower the mortality rate, and reduce the cost of hospitalization.</p>

Cloning, sequencing and expression analysis of the NAR promoter activated during hyphal stage of Magnaporthe grisea / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The promoter of NAR gene in Magnaporthe grisea was isolated and sequenced. The promoter sequences contained the "TATA" box, the "CAAT" box, and binding sites for fungal regulatory proteins. Programs that predict promoter sequences indicated that promoter sequence lies between locations 430 and 857 of the NAR promoter fragment. GFP expression under the NAR promoter and NAR transcript analysis revealed that this promoter is activated primarily at the mycelial stage in the rice blast fungus and could be used to express native or extrinsic genes in the mycelia of the rice blast fungus.

Promoter trapping in Magnaporthe grisea / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Application of promoter trapping based on transformation in Magnaporthe grisea is reported in this paper. Two promoter-trapping vectors, designated as pCBGFP and pEGFPHPH, were constructed and transformed into protoplasts of M. grisea. A library of 1,077 transformants resistant to hygromycin B was generated. Of which, 448 transformants were found to express eGFP gene in different structures of M. grisea. Three transformants grew slowly, 5 transformants decreased in conidiation and 7 transformants reduced in pathogenicity greatly among these 448 transformants. Eleven transformants were checked by genomic southern blot randomly, and 9 of which were single-copy insertions. The promoter trapping technique has been applied successfully in M. grisea and can be used as a tool for functional genomic analysis.

Structural changes of oviduct of freshwater shrimp, Macrobrachium nipponense (Decapoda, Palaemonidae), during spawning / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The structural change of the oviduct of freshwater shrimp (Macrobrachium nipponense) during spawning was examined by electron microscopy. The oviduct wall structural characteristics seem to be influenced significantly by the spawning process. Before the parturition and ovulation, two types of epithelial cells (types I and II) are found in the epithelium. The free surfaces of type I and type II cells have very dense long microvilli. Under the type I and type II cells, are a relatively thick layer of secreting material and a layer of mostly dead cells. After ovulation, two other types of epithelial cells (types III and IV) are found in the oviduct wall epithelium. The free surface of type III cells only has short microvilli scattered on the surface. The thick layer with secreting material and the dead cell layer disappeared at this stage. In some type III cells, the leaking out of cytoplasm from broken cell membrane led to the death of these type III cells. The transformation of all four types of epithelial cells was in the order: IV-->I-->II-->III.

Evaluation of cerebral vasospasm resulting from subarachnoid hemorrhage with 1H-magnetic resonance spectroscopy / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of (1)H-magnetic resonance spectroscopy ((1)H-MRS) in evaluating cerebral vasospasm resulting from subarachnoid hemorrhage (SAH).</p><p><b>METHODS</b>Six dogs were subjected to autologous non-heparinized blood injection via cisternal puncture twice at one-day interval to establish models of SAH, and another 6 received injections with normal saline in an identical manner. (1)H-MRS scan was performed on the 3rd, 7th and 14th days after the injections to measure the changes of N-acetylaspartate (NAA), creatine (Cr) and choline (Cho). After the (1)H-MRS scan, all the dogs underwent brain digital subtraction angiography (DSA) for determining the basilar artery diameter.</p><p><b>RESULTS</b>DSA results on day 3 presented development of obvious vasospasm of the basilar artery, which was most evident on day 7 and recovered obviously on day 14. (1)H-MRS results demonstrated obvious changes of NAA, Cho and Cr on days 3 and 7 in SAH model group, and NAA declined to the lowest level on day 3 followed by gradual ascending till reaching the normal level on day 14. Cho decreased slightly on day 3, then increased and reached the peak level on day 7 and then decreased. Cr rose steadily from day 3 to 14, but since day 7, the rise slowed down obviously and Cr maintain a level not significantly different from that on day 14 (P>0.05). The functional results of (1)H-MRS were consistent with the DSA results.</p><p><b>CONCLUSION</b>(1)H-MRS can be used to monitor the development of cerebral vasospasm resulting from SAH as a good evaluation method for functional imaging.</p>

Natural history of small hepatocellular carcinoma: studied by MRI / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study natural history of small hepatocellular carcinoma (sHCC) and value of MRI in this research.</p><p><b>METHODS</b>From 1999 to 2002, serial MR imagings were performed in 192 patients with cirrhosis no less than twice in order to detect sHCC focus. Characteristic MRI findings of focus were analysed. Diameters of focus (D) were measured. Tumorigenesis detected time (T) was counted; T and D were analysed by statistics and tumor volume doubling time (T(d)) was calculated.</p><p><b>RESULTS</b>Fifty-eight new tumor foci in 33 patients were found, including 31 foci in 23 patients developed on the basis of cirrhosis, with a 12.0% cumulative tumorigenic rate of three years. The tumorigenesis detected time (T) was 386.9 +/- 256.4 days and the maximum diameter (D) was 2.258 +/- 1.074 cm. T was statistical correlated with D(3) (P < 0.01) and regressive formulas were established: D(3) = -2.69 + 0.058T (P = 0.0007), D(3) = -72.13 + 16.04lnT (P = 0.0064). Tumor volume doubling time was 20 approximately 279 days (mean: 104 days).</p><p><b>CONCLUSION</b>The percentage of tumorigenesis is high in patients with cirrhosis. Regular MRI examinations are necessary to detect sHCC early. The optimal interval time is 3 approximately 6 months.</p>

Representative appressorium stage cDNA library of Magnaporthe grisea / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

A mature appressorium cDNA library of rice blast fungus, Magnaporthe grisea, was constructed in a lambdaTriplEx2 vector by SMART cDNA library containing 2.37x10(6) independent clones about 100% of which harbor foreign cDNA inserts with average size of 660 bp. Of 9 randomly selected clones, 2 expressed sequence tags (ESTs) sequences did not have homologous EST sequences of M. grisea in GenBank. The appressorium cDNA library is suitable for gene expression analysis and function analysis of the late stages of appressorium formation and the early stages of penetration of M. grisea.

Sequence analysis and expression pattern of MGTA1 gene in rice blast pathogen Magnaporthe grisea / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

MGTA1, a putative fungal Zn(II)(2)Cys(6) transcriptional activator-encoding gene, was isolated from rice blast pathogen Magnaporthe grisea, which is homologous to CLTA1 from Colletotrichum lindemuthianum with 51% identity at protein level. MGTA1 cassette contains a 2370 bp open reading frame, consisting of 6 exons, coding a 790 amino acid peptide. MGTA1 gene exists as a single copy in genomes of 7 strains of M. grisea, and is expressed in tip hyphae, conidia, and mature appressoria of strain Guy11.

Clinical value of MR cholangiopancreatography combining with dynamic enhanced MRI in the detection of cholangiocarcinoma / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To evaluate the clinical value of breath-hold magnetic resonance cholangiopancreatography (MRCP) combining with dynamic enhanced MRI in the diagnosis of cholangiocarcinoma.</p><p><b>METHODS</b>MRCP findings of 88 cholangiocarcinoma patients proved surgically and pathologically were analyzed retrospectively.</p><p><b>RESULTS</b>MRCP examination succeeded in all the 88 patients and the pancreaticobiliary ducts were shown satisfactorily. The accuracy of MRCP in the location of both hilar and extrahepatic cholangiocarcinoma was 100%, and the accuracy of detecting hilar and extrahepatic cholangiocarcinoma were 100% and 52.2%, respectively. Combining with dynamic enhanced MRI, the detecting accuracy of extrahepatic cholangiocarcinoma improved to 91.3%.</p><p><b>CONCLUSIONS</b>MRCP examination has a high successful rate and can accurately determine the location of hilar and extrahepatic cholangiocarcinoma, and the accuracy of qualitative diagnosis for the former two is high. Combining with dynamic enhanced MRI, the specificity of determining extrahepatic cholangiocarcinoma is also high.</p>

Diffusion tensor tractography of normal and compressed spinal cord:a preliminary study at 3.0 T MR / 中华放射学杂志

Objective To study the feasibility and clinical values of diffusion tensor tractography (DTT)in the spinal cord at 3.0 T MR.Methods Forty patients with spinal cord compression including cervical cord herniation and cervical spondylosis(30 cases),tumors in spinal canal(9 cases)and old injury in cervical vertebrae(1 cases)and 20 healthy volunteers participated in this study.Single-shot spin- echo echo-planar diffusion tensor sequence for tractography of the spinal cord was performed.The fibers of spinal cord were visualized by using fiber tracking software.Results On the DTT maps,the normal spinal cord was depicted as a fiber tract showing color-encoded cephaloeaudally,which indicated anisotropy in the cephalocaudal direction.By setting two ROI,the main spinal cord fiber tracts,such as corticospinal or spinothalamic tract,were visualized.The tracts from two sides of the brain did not completely cross.It was asymmetric in the number of tracts on the two sides in most normal subjects(8/10).The tracts of all patients with cord compression were seen oppressed or damaged in different degrees.The DrrT in patients with cervical spondylosis and extramedullary-intradural neurolemmoma demonstrated that tracts were oppressed but not damaged.The DTT in one ependymoma showed that tract was markedly compressed and slightly damaged.Conclusion DTT is a promising tool for demonstrating the spinal cord tracts and abnormalities,can provide useful information for the localization of compression and evaluation of the impairment extent on the white matter tracts of the spinal cord.

Three-dimensional contrast-enhanced MR angiography in diagnosis of cerebral arteriovenous malformation / 中华放射学杂志

Objective To evaluate the value of three-dimensional contrast-enhanced angiography (3D CE MRA) and MRI in the diagnosis and delineation of cerebral arteriovenous malformation(AVM). Methods Twenty-two cases of cerebral AVM examined by MRI and 3D CE,MRA.DSA was performed in 17 cases.A three-dimensional fast low angle shot (3D FLASH) was used for 3D CE MRA with Gd-DTPA dosage of 0.2 mmol per kilogram for body weight.The source images were subtracted from mask images and transferred to computer workstation using three-dimensional reconstruction.Results Among 22 cases, 19 showed typical AVM“flow void”signal on MR images.3D CE MRA clearly displayed the nidus,feeding artery and draining vein.All of the foci were above the cerebellum tentorium.13 located within one lobe, 3 exceeded one lobe and 3 situated in the deep of cerebrum.Feeding arteries were derived from single artery in 9 cases,and mixed supply in 10 cases.Draining veins diverted to sagittal sinus and/or sigmoid sinus in 6,deep cerebral veins in 8 and mixed in 5.In the 14 cases examined by both DSA and 3D CE MRA,3D CE MRA was superior to DSA in three-dimensional demonstration of the nidus,but inferior to DSA in demonstration of some details.3D CE MRA depicted 78.4% feeding arteries and 84.0% draining veins in addition,tiny pathologic blood vessels smaller than 1 centimeter were detected by DSA,but could not be found by 3D CE MRA and were only shown as hemorrhage lesions on MR images in 3 cases.Conclusion As a non-invasive technique,3D CE MRA combined with MRI is accurate in diagnosis and localization of cerebral AVM,and should be used as the first choice for those clinically suspected of AVM.But DSA remains needed for demonstration of details and tiny AVM.