BACKGROUND Percutaneous endoscopic lumbar decompression(PELD)shows promise for lumbar spinal stenosis(LSS)treatment,but its use is limited by the disease's complexity and procedural challenges.AIM In this study,th...BACKGROUND Percutaneous endoscopic lumbar decompression(PELD)shows promise for lumbar spinal stenosis(LSS)treatment,but its use is limited by the disease's complexity and procedural challenges.AIM In this study,the effects of preoperative planning and intraoperative guidance with computed tomography(CT)/magnetic resonance imaging(MRI)registration techniques on PELD for LSS and postoperative rehabilitation outcomes were evaluated.METHODS This retrospective study was conducted with data from patients who underwent PELD for LSS between January 2021 and December 2023.Patients were assigned to preoperative CT/MRI registration and control groups.Data collected included the operative time,length of hospital stay,visual analog scale(VAS)scores for low back and leg pain,and the Japanese Orthopaedic Association(JOA)lumbar spine score.Differences between groups were assessed using Student’s t test.RESULTS Data from 135 patients(71 in the CT/MRI registration group,64 in the control group)were analyzed.The operative time was significantly shorter in the CT/MRI registration group(P=0.007).At 2 months postoperatively,both groups showed significant reductions in VAS leg and low back pain scores(all P<0.001)and improvements in the JOA score(both P<0.001).No complication or death occurred.Preoperatively,pain and JOA scores were similar between groups(P=0.830,P=0.470,and P=0.287,respectively).At 2 months postoperatively,patients in the CT/MRI registration group reported lower leg and low back pain levels(P<0.001 and P=0.001,respectively)and had higher JOA scores(P=0.004)than did patients in the control group.CONCLUSION Preoperative CT/MRI registration for PELD for LSS reduced the operative time and VAS pain scores at 2 months and improved JOA scores,demonstrating enhanced effectiveness and safety.展开更多
There is a large amount of fat in the postganglionic segment of the brachial plexus nerve.The use of short T1 inversion recovery pulse sequence may improve signal strength of the brachial plexus postganglionic segment...There is a large amount of fat in the postganglionic segment of the brachial plexus nerve.The use of short T1 inversion recovery pulse sequence may improve signal strength of the brachial plexus postganglionic segment.The present study revealed that the combination of three-dimensional fast imaging employing steady-state acquisition with phase-cycled and short T1 inversion recovery pulse sequence clearly displayed the anatomical morphology and structure of the brachial plexus nerve,together with maximum intensity projection,volume rendering and other three-dimensional reconstruction techniques.Our results suggested that this method is also suitable for providing accurate assessment and diagnosis of the site,severity and scope of brachial plexus injury.展开更多
There have been many advances in the diagnosis and management of focal epilepsies particularly with neuroimaging techniques and magnetic resonance imaging(MRI).Special MRI sequences can be employed to localize and res...There have been many advances in the diagnosis and management of focal epilepsies particularly with neuroimaging techniques and magnetic resonance imaging(MRI).Special MRI sequences can be employed to localize and resect the epileptogenic lesions responsible for focal epilepsy.This study aims to show the benefit of dedicated epilepsy MRI sequences in the diagnosis of focal epilepsies.A general electric 1.5 Tesla MRI machine was used with standard and special sequences.Also,a Nihon Kohden electroencephalography(EEG)machine was used.This is a prospective observational study that included 51 patients with focal epilepsies who had an initial negative brain imaging.They underwent epilepsy MRI sequences along with a prolonged video EEG monitoring to localize the lesion,and then results were analyzed statistically using SPSS 22 program.The majority of patients were males(62.75%)with a mean age of 30 years.The grand majority of patients(74.5%,p value of 0.001)had their lesion localized by the epilepsy MRI.The most commonly found pathology was mesial temporal sclerosis.A significant number of patients(23.5%)were sent for an epilepsy surgery(p value 0.002).This study shows the significant impact of dedicated epilepsy MRI sequences on the diagnosis and management of focal epilepsy in the Lebanese population.展开更多
AIM To assess the correlation of lateral recess stenosis(LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS Nine hundred and twenty-seven patients with history of low back pain were ...AIM To assess the correlation of lateral recess stenosis(LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS Nine hundred and twenty-seven patients with history of low back pain were included in this uncontrolled study.On magnetic resonance images(MRI) the lateral recesses(LR) at lumbar levels L4/5 and L5/S1 were evaluated and each nerve root was classified into a 4-point grading scale(Grade 0-3) as normal,not deviated,deviated or compressed.Patient symptoms and disability were assessed using ODI.The Spearman's rank correlation coefficient was used for statistical analysis(P < 0.05).RESULTS Approximately half of the LR revealed stenosis(grade 1-3;52% at level L4/5 and 42% at level L5/S1) with 2.2% and 1.9% respectively reveal a nerve root compression.The ODI score ranged from 0%-91.11% with an arithmetic mean of 34.06% ± 16.89%.We observed a very weak statistically significant positive correlation between ODI and LRS at lumbar levels L4/5 and L5/S1,each bilaterally(L4/5 left:rho < 0.105,P < 0.01;L4/5 right:rho < 0.111,P < 0.01;L5/S1 left:rho 0.128,P < 0.01;L5/S1 right:rho < 0.157,P < 0.001).CONCLUSION Although MRI is the standard imaging tool for diagnosing lumbar spinal stenosis,this study showed only a weak correlation of LRS on MRI and clinical findings.This can be attributed to a number of reasons outlined in this study,underlining that imaging findings alone are not sufficient to establish a reliable diagnosis for patients with LRS.展开更多
AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects wit...AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated. In each study, the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table (A-angle), as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum (B-angle). RESULTS: The total study population consisted of 100 subjects (46 males, 54 females, 51 ± 16 years old). There were no differences in age and sex between the two groups. Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls (P < 0.05). The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8° (sensitivity = 80%, specificity = 80%, accuracy = 83%; 95% confidence interval = 74%-89%, P = 0.0001) and 35.9° (sensitivity = 80%, specificity = 54%, accuracy = 69%; 95% confidence interval = 59%-78%, P = 0.0005), respectively. CONCLUSION: On sagittal MR images of the lumbar spine, an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV.展开更多
AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects w...AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects with CLSS and 48 control subjects were retrospectively evaluated. In each examination, the five lumbar levels were assessed for the presence or absence of circumferential or shallow annular bulges, annular tears, anterior or posterior disc herniations, epidural lipomatosis, Schmorl's nodes,spondylolisthesis, pars defects, and stress reactions of the posterior vertebral elements. RESULTS: Compared to control individuals, subjects with CLSS exhibited increased incidence of circumferential and shallow annular bulges, annular tears, discherniations and spondylolisthesis(P < 0.05). CONCLUSION: CLSS is associated with increased incidence of degenerative changes in specific osseous and soft-tissue elements of the lumbar spine.展开更多
BACKGROUND Most cases of Apert syndrome(AS)are found after birth.Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging(MRI)and whole exome sequencing(WES)during pregnancy are rare.CASE SUMMARY W...BACKGROUND Most cases of Apert syndrome(AS)are found after birth.Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging(MRI)and whole exome sequencing(WES)during pregnancy are rare.CASE SUMMARY We present the case of a 34-year old female patient(gravida 2,para 1)whose fetus was diagnosed with AS during pregnancy.Fetal ultrasound performed at 30,2/7 wk of pregnancy showed abnormalities.MRI and three-dimensional ultrasound performed at 31,1/7 wk of pregnancy showed the possibility of AS.Chromosome examination and core family WES were conducted at 31,5/7 wk of pregnancy.The results showed that FGFR2 in the fetus had a c.755C>G missense mutation in its nucleotide,and AS was confirmed.CONCLUSION This case highlights the importance of imaging examinations.Prenatal ultrasound combined with MRI can identify fetal morphological abnormalities accurately,which can be confirmed by WES.展开更多
BACKGROUND The response to axial physiological pressure due to load transfer to the lumbar spine structures is among the various back pain mechanisms.Understanding the spine adaptation to cumulative compressive forces...BACKGROUND The response to axial physiological pressure due to load transfer to the lumbar spine structures is among the various back pain mechanisms.Understanding the spine adaptation to cumulative compressive forces can influence the choice of personalized treatment strategies.AIM To analyze the impact of axial load on the spinal canal’s size,intervertebral foramina,ligamenta flava and lumbosacral alignment.METHODS We assessed 90 patients using three-dimensional isotropic magnetic resonance imaging acquisition in a supine position with or without applying an axial compression load.Anatomical structures were measured in the lumbosacral region from L1 to S1 in lying and axially-loaded magnetic resonance images.A paired t test atα=0.05 was used to calculate the observed differences.RESULTS After axial loading,the dural sac area decreased significantly,by 5.2%on average(4.1%,6.2%,P<0.001).The intervertebral foramina decreased by 3.4%(2.7%,4.1%,P<0.001),except for L5-S1.Ligamenta flava increased by 3.8%(2.5%,5.2%,P<0.001),and the lumbosacral angle increased.CONCLUSION Axial load exacerbates the narrowing of the spinal canal and intervertebral foramina from L1-L2 to L4-L5.Cumulative compressive forces thicken ligamenta flava and exaggerate lumbar lordosis.展开更多
Objective: To assess the importance of incidental extraspinal findings on Magnetic Resonance Imaging of the lumbar spine in two hospital facilities. Materials and Methods: It was a descriptive and retrospective study ...Objective: To assess the importance of incidental extraspinal findings on Magnetic Resonance Imaging of the lumbar spine in two hospital facilities. Materials and Methods: It was a descriptive and retrospective study from November 2015 to March 2016. The records of patients who had done a Magnetic Resonance Imaging (MRI) scan of the lumbar spine were re-read in search of incidental findings. The incidental findings found were classified using Colonography Reporting and Data System(C-RADS) classification of extracolonic lesions to assess clinical significance. The prevalence of incidental findings was calculated for each facility, as well as the distribution according to age, the organs involved and the clinical importance. A non-detection rate was calculated by confronting the findings of the study with the original reports. Results: The prevalence of incidental findings was respectively 33% (19 out of 36) in Jordan Medical Center (JMC) in Yaounde and 27.74% (106 out of 292) in Jacques Monod Hospital. The extraspinal incidental findings were classified mainly as extracolonic 2 (E2): 58% in each facility. The percentage detection of incidental findings was 5% at JMS and 1.7% at Jacques Monod Hospital. Conclusion: Extraspinal incidental findings are frequent in both hospitals. However, the rate of detection remains very low.展开更多
BACKGROUND Redundant nerve roots(RNRs)of the cauda equina are often a natural evolutionary part of lumbar spinal canal stenosis secondary to degenerative processes characterized by elongated,enlarged,and tortuous nerv...BACKGROUND Redundant nerve roots(RNRs)of the cauda equina are often a natural evolutionary part of lumbar spinal canal stenosis secondary to degenerative processes characterized by elongated,enlarged,and tortuous nerve roots in the superior and/or inferior of the stenotic segment.Although magnetic resonance imaging(MRI)findings have been defined more frequently in recent years,this condition has been relatively under-recognized in radiological practice.In this study,lumbar MRI findings of RNRs of the cauda equina were evaluated in spinal stenosis patients.AIM To evaluate RNRs of the cauda equina in spinal stenosis patients.METHODS One-hundred and thirty-one patients who underwent lumbar MRI and were found to have spinal stenosis between March 2010 and February 2019 were included in the study.On axial T2-weighted images(T2WI),the cross-sectional area(CSA)of the dural sac was measured at L2-3,L3-4,L4-5,and L5-S1 levels in the axial plane.CSA levels below 100 mm^2 were considered stenosis.Elongation,expansion,and tortuosity in cauda equina fibers in the superior and/or inferior of the stenotic segment were evaluated as RNRs.The patients were divided into two groups:Those with RNRs and those without RNRs.The CSA cut-off value resulting in RNRs of cauda equina was calculated.Relative length(RL)of RNRs was calculated by dividing the length of RNRs at mid-sagittal T2WI by the height of the vertebral body superior to the stenosis level.The associations of CSA leading to RNRs with RL,disc herniation type,and spondylolisthesis were evaluated.RESULTS Fifty-five patients(42%)with spinal stenosis had RNRs of the cauda equina.The average CSA was 40.99±12.76 mm^2 in patients with RNRs of the cauda equina and 66.83±19.32 mm^2 in patients without RNRs.A significant difference was found between the two groups for CSA values(P<0.001).Using a cut-off value of 55.22 mm^2 for RNRs of the cauda equina,sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)values of 96.4%,96.1%,89.4%,and 98.7%were obtained,respectively.RL was 3.39±1.31(range:0.93-6.01).When the extension of RNRs into the superior and/or inferior of the spinal canal stenosis level was evaluated,it was superior in 54.5%,both superior and inferior in 32.8%,and inferior in 12.7%.At stenosis levels leading to RNRs of the cauda equina,29 disc herniations with soft margins and 26 with sharp margins were detected.Disc herniation type and spondylolisthesis had no significant relationship with RL or CSA of the dural sac with stenotic levels(P>0.05).As the CSA of the dural sac decreased,the incidence of RNRs observed at the superior of the stenosis level increased(P<0.001).CONCLUSION RNRs of the cauda equina are frequently observed in patients with spinal stenosis.When the CSA of the dural sac is<55 mm^2,lumbar MRIs should be carefully examined for this condition.展开更多
Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the s...Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the spine.The semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar diseases.It is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation accuracy.This work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra S1.Pseudo-colour mask images were generated and used as ground truth for training the model.The work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley Data.The proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.展开更多
Far lateral lumbar disc herniations(FLLDH)represent a separate category of disc pathology which includes both intraforaminal and extraforaminal lumbar disc herniations,that are characterized by a peculiar clinical pre...Far lateral lumbar disc herniations(FLLDH)represent a separate category of disc pathology which includes both intraforaminal and extraforaminal lumbar disc herniations,that are characterized by a peculiar clinical presentation,diagnostic and treatment modalities as compared to the more frequent median and paramedian disc hernias.Surgical treatment often represents the only effective weapon for the cure of this disease and over the years different approaches have been developed that can reach the region of the foramen or external to it,with different degrees of invasiveness.The diagnosis is more demanding and still underestimated as it requires a more detailed knowledge in the spine anatomy and dedicated radiological studies.Computerized tomography and in particular magnetic resonance imaging are the appropriate tools for the diagnosis of FLLDH.Despite the widespread use of these diagnostic tests,many cases of FLLDH are overlooked due to insufficiently detailed radiological examinations or due to the execution of exams not focused to the foraminal or the extraforaminal region.Neurophysiological studies represent a valid aid in the diagnostic classification of this pathology and in some cases they can facilitate the differential diagnosis with other types of radiculopathies.In the present study,a comprehensive review of the clinical presentation,epidemiology,radiological study and the neurophysiological aspects is presented.展开更多
Because of the small diameter and complex anatomic course of the cranial nerves except for the optic nerve, trigeminal nerve, facial nerve, and cochlear and vestibular nerve, other cranial nerves are difficult to be v...Because of the small diameter and complex anatomic course of the cranial nerves except for the optic nerve, trigeminal nerve, facial nerve, and cochlear and vestibular nerve, other cranial nerves are difficult to be visualized in magnetic resonance imaging (MRI) scanning with conventional thickness (5-10 mm). With the rapid development of MRI technology high spatial resolution, three-dimensional and two-dimensional magnetic resonance imaging technologies have been used in recent years in the observation of normal and abnormal cranial nerves, including three-dimensional constructive interference in steady state (3D CISS) sequence, three- dimensional magnetization-prepared rapid gradient-echo (3D MP-RAGE) sequence, three-dimensional fast inflow with steady-state precession (3D FISP) seohuence, and some fast spin-echo (FSE) sequences. - Threedimensional fast imaging employing steady-state acquisition (3D-FIESTA) is a fast three-dimensional steady-state imaging sequence with high spatial resolution and contrast between the organizational structures. And this sequence was reportedly used in the study on the diseases in the cerebellopontine angle; inner ear and posterior fossa tumors.7'8 However, the reports about the value of 3D-FIESTA sequence for the visualization of normal cranial nerves are still rare.展开更多
Objective This study aimed to develop and test a model for predicting dysthyroid optic neuropathy(DON)based on clinical factors and imaging markers of the optic nerve and cerebrospinal fluid(CSF)in the optic nerve she...Objective This study aimed to develop and test a model for predicting dysthyroid optic neuropathy(DON)based on clinical factors and imaging markers of the optic nerve and cerebrospinal fluid(CSF)in the optic nerve sheath.Methods This retrospective study included patients with thyroid-associated ophthalmopathy(TAO)without DON and patients with TAO accompanied by DON at our hospital.The imaging markers of the optic nerve and CSF in the optic nerve sheath were measured on the water-fat images of each patient and,together with clinical factors,were screened by Least absolute shrinkage and selection operator.Subsequently,we constructed a prediction model using multivariate logistic regression.The accuracy of the model was verified using receiver operating characteristic curve analysis.Results In total,80 orbits from 44 DON patients and 90 orbits from 45 TAO patients were included in our study.Two variables(optic nerve subarachnoid space and the volume of the CSF in the optic nerve sheath)were found to be independent predictive factors and were included in the prediction model.In the development cohort,the mean area under the curve(AUC)was 0.994,with a sensitivity of 0.944,specificity of 0.967,and accuracy of 0.901.Moreover,in the validation cohort,the AUC was 0.960,the sensitivity was 0.889,the specificity was 0.893,and the accuracy was 0.890.Conclusions A combined model was developed using imaging data of the optic nerve and CSF in the optic nerve sheath,serving as a noninvasive potential tool to predict DON.展开更多
We want to explore the analgesic brain effect of the moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation(LDH)and myofascial pain syndrome(MPS).In an assessor-blinded observational st...We want to explore the analgesic brain effect of the moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation(LDH)and myofascial pain syndrome(MPS).In an assessor-blinded observational study,we will include 15 LDH and 15 MPS.They will accept same treatment of heat-sensitive moxibustion at Yaoyangguan(GV3).The resting-state functionality magnetic resonance imaging image data of brain activities before and after treatment will be analyzed by mean fractional amplitude of low-frequency fluctuation,regional homogeneity analysis and brain functional connection.We select seed of first sensory cortex,second sensory cortex,insula cortex,periaqueductal gray and anterior cingulate cortex as the regions of interest to analyse the relationship between brain functional connectivity of pain-related networks and clinical data.Our study could disclose key brain targets and central response characteristics of the analgesic brain effect and the brain functional connection of heat-sensitive moxibustion.展开更多
Magnetic Resonance Elastography (MRE) is a noninvasive technique to measure elas-ticity of tissues in vivo. In this paper, a mechanical shear wave MR imaging system experiment is set for MRE. A novel actuator is propo...Magnetic Resonance Elastography (MRE) is a noninvasive technique to measure elas-ticity of tissues in vivo. In this paper, a mechanical shear wave MR imaging system experiment is set for MRE. A novel actuator is proposed to generate me-chanical shear waves propagating inside a gel phantom. The actuator is made of piezoelectric ce-ramics, and fixed on a plexiglass bracket. Both of the gel phantom and the actuator are put into a head coil inside the MR scanner’s bore. The actuator works synchronously with an MR imaging sequence running on the MR scanner. The sequence is modified from a FLASH sequence into a motion-sensitizing phase- contrast sequence for shear wave MR imaging. Shear wave images are presented, and these effects on the shear wave MR imaging system, including the stiffness of phantoms, the frequency of the actuator, the parameters of the motion-sensitizing gradient, and the oscillation of the patient bed, are discussed.展开更多
Background Detection rate of retropharyngeal lymph node metastasis in patients with nasopharyngeal carcinoma (NPC) needs to be improved. The purpose of this study was to compare three magnetic resonance (MR) seque...Background Detection rate of retropharyngeal lymph node metastasis in patients with nasopharyngeal carcinoma (NPC) needs to be improved. The purpose of this study was to compare three magnetic resonance (MR) sequences for detecting lymph nodes in patients with NPC. Methods Between July 2007 and March 2008, MR staging of pre-treated tumor was conducted on 120 patients with pathologically confirmed NPC. The outcome of three different sequences for MR NPC staging were compared: coronal short T1 inversion recovery (STIR), axial proton density fat-suppressed (PDWI fs), and coronal contrast enhanced fast spin echo T1 weighted fat-suppressed (CE FSE TlWl fs). Nodal classification method (1999) was applied to count the number of retropharyngeal and cervical lymph nodes discovered by each MR sequence. Paired t tests were used for statistical analysis. Results A total of 2575 lymph nodes were found using coronal STIR sequence; 1816 lymph nodes for coronal CE FSE TIWI fs sequence and 2638 lymph nodes for axial PDWl fs sequence. Significant differences existed in the number of lymph nodes detected by axial PDWI fs and coronal CE FSE T1WI fs sequence (paired t test, P 〈0.05), with the former sequence getting higher numbers. Statistical differences also existed between coronal STIR and coronal CE FSE TlWl fs sequence (paired ttest, P 〈0.05), with the former sequence getting higher numbers. No significant difference was found between coronal STIR sequence and axial PDWI fs sequence (paired ttest, P 〉0.05). Conclusions For the detection of retropharyngeal and cervical lymph nodes, coronal STIR sequence and axial PDWI fs sequence have similar performance and both sequences showed better detection than CE FSE TIWI fs sequence. Furthermore, by combining coronal STIR sequence and axial PDWI fs sequence, we can improve the detection of lymph nodes in NPC N-staging before treatment, especially for lymph nodes located in the thoracic entrance.展开更多
Fat-suppression technology of magnetic resonance is very important in clinical practice.This article is written to interpret the principle, advantages/disadvantages and clinical applications of some regular fat-suppre...Fat-suppression technology of magnetic resonance is very important in clinical practice.This article is written to interpret the principle, advantages/disadvantages and clinical applications of some regular fat-suppression sequences in the diagnosis of Bone-Joint Disease, including 1) frequency-selective saturation (FS);2) short-TI inversion recovery (STI-R);3)frequency selective inversion pulse;4) fat suppression water or fat selective excitation technique;5) Dixon technology and 6) magnetization transfer contrast (MTI).展开更多
The purpose of this study was to analyze the lesion brightness (image contrast) in multiple MRI sequences in patients with relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), primary progressive MS (PPMS),...The purpose of this study was to analyze the lesion brightness (image contrast) in multiple MRI sequences in patients with relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), primary progressive MS (PPMS), and clinically isolated syndrome (CIS);and to correlate the lesion contrast with lesion volumes and neurological disability. MRI ex- amination at 1.5 T was performed on 80 patients with RRMS, SPMS, PPMS, or CIS. The protocol included T1- and T2-weighted spin echo (SE), fluid attenuated inversion recovery (FLAIR), T1-weighted SE with magnetization transfer preparation, and diffusion weighted imaging (DWI). Contrast was measured between MS lesions and normal appearing white matter. Lesion volume was calculated in T1-weighted- and FLAIR-images. All patients were examined neurologically including evaluation of expanded disability status scale (EDSS) score. Lesion contrast correlated with total brain lesion volume (p = 0.000 - 0.040). In patients with low EDSS, three sequences were able to differentiate between CIS and RRMS. SPMS and PPMS were separated by DWI. Lesion contrast correlated with EDSS score on T1-weighted imaging, with or without magnetization transfer preparation. Patient age correlated with lesion contrasts. Contrast measurements seem limited in radiological and clinical diagnosis of MS in reference to disease course, its activity and progression. The differentiation between MS subgroups might improve at 3 T and could help in leading to earlier treatment of the disease.展开更多
Purpose:To preliminarily investigate the application value of rapid sequences FFE and SSh-TSE in ocular magnetic resonance imaging(MRI).Methods:Ocular MRI was performed in 18 subjects without ocular conditions,and dem...Purpose:To preliminarily investigate the application value of rapid sequences FFE and SSh-TSE in ocular magnetic resonance imaging(MRI).Methods:Ocular MRI was performed in 18 subjects without ocular conditions,and demonstration of 15 delicate anatomic structures on two sequences in each subject was rated by three proficient physicians.Results:FFE sequence was comparatively advantageous in demonstrating delicate structures on ocular wall and ocular adnexa(P<0.001) over SSh-TSE;while SSh-TSE sequence better revealed the delicate anatomy within anterior chamber(P<0.001) and optic nerve sheath(P<0.05),with statistically significant differences compared with FFE.Conclusion:Optimized FFE and SSh-TSE sequences are able to effectively eliminate the impact from motion artifact and thus result in desirable images with high spatial resolution.The application of high-resolution MR microscopic imaging technique has improved the ability to demonstrate delicate ocular structures.展开更多
基金Supported by Health Commission of Shanxi Province,No.2021XM39.
文摘BACKGROUND Percutaneous endoscopic lumbar decompression(PELD)shows promise for lumbar spinal stenosis(LSS)treatment,but its use is limited by the disease's complexity and procedural challenges.AIM In this study,the effects of preoperative planning and intraoperative guidance with computed tomography(CT)/magnetic resonance imaging(MRI)registration techniques on PELD for LSS and postoperative rehabilitation outcomes were evaluated.METHODS This retrospective study was conducted with data from patients who underwent PELD for LSS between January 2021 and December 2023.Patients were assigned to preoperative CT/MRI registration and control groups.Data collected included the operative time,length of hospital stay,visual analog scale(VAS)scores for low back and leg pain,and the Japanese Orthopaedic Association(JOA)lumbar spine score.Differences between groups were assessed using Student’s t test.RESULTS Data from 135 patients(71 in the CT/MRI registration group,64 in the control group)were analyzed.The operative time was significantly shorter in the CT/MRI registration group(P=0.007).At 2 months postoperatively,both groups showed significant reductions in VAS leg and low back pain scores(all P<0.001)and improvements in the JOA score(both P<0.001).No complication or death occurred.Preoperatively,pain and JOA scores were similar between groups(P=0.830,P=0.470,and P=0.287,respectively).At 2 months postoperatively,patients in the CT/MRI registration group reported lower leg and low back pain levels(P<0.001 and P=0.001,respectively)and had higher JOA scores(P=0.004)than did patients in the control group.CONCLUSION Preoperative CT/MRI registration for PELD for LSS reduced the operative time and VAS pain scores at 2 months and improved JOA scores,demonstrating enhanced effectiveness and safety.
文摘There is a large amount of fat in the postganglionic segment of the brachial plexus nerve.The use of short T1 inversion recovery pulse sequence may improve signal strength of the brachial plexus postganglionic segment.The present study revealed that the combination of three-dimensional fast imaging employing steady-state acquisition with phase-cycled and short T1 inversion recovery pulse sequence clearly displayed the anatomical morphology and structure of the brachial plexus nerve,together with maximum intensity projection,volume rendering and other three-dimensional reconstruction techniques.Our results suggested that this method is also suitable for providing accurate assessment and diagnosis of the site,severity and scope of brachial plexus injury.
文摘There have been many advances in the diagnosis and management of focal epilepsies particularly with neuroimaging techniques and magnetic resonance imaging(MRI).Special MRI sequences can be employed to localize and resect the epileptogenic lesions responsible for focal epilepsy.This study aims to show the benefit of dedicated epilepsy MRI sequences in the diagnosis of focal epilepsies.A general electric 1.5 Tesla MRI machine was used with standard and special sequences.Also,a Nihon Kohden electroencephalography(EEG)machine was used.This is a prospective observational study that included 51 patients with focal epilepsies who had an initial negative brain imaging.They underwent epilepsy MRI sequences along with a prolonged video EEG monitoring to localize the lesion,and then results were analyzed statistically using SPSS 22 program.The majority of patients were males(62.75%)with a mean age of 30 years.The grand majority of patients(74.5%,p value of 0.001)had their lesion localized by the epilepsy MRI.The most commonly found pathology was mesial temporal sclerosis.A significant number of patients(23.5%)were sent for an epilepsy surgery(p value 0.002).This study shows the significant impact of dedicated epilepsy MRI sequences on the diagnosis and management of focal epilepsy in the Lebanese population.
文摘AIM To assess the correlation of lateral recess stenosis(LRS) of lumbar segments L4/5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS Nine hundred and twenty-seven patients with history of low back pain were included in this uncontrolled study.On magnetic resonance images(MRI) the lateral recesses(LR) at lumbar levels L4/5 and L5/S1 were evaluated and each nerve root was classified into a 4-point grading scale(Grade 0-3) as normal,not deviated,deviated or compressed.Patient symptoms and disability were assessed using ODI.The Spearman's rank correlation coefficient was used for statistical analysis(P < 0.05).RESULTS Approximately half of the LR revealed stenosis(grade 1-3;52% at level L4/5 and 42% at level L5/S1) with 2.2% and 1.9% respectively reveal a nerve root compression.The ODI score ranged from 0%-91.11% with an arithmetic mean of 34.06% ± 16.89%.We observed a very weak statistically significant positive correlation between ODI and LRS at lumbar levels L4/5 and L5/S1,each bilaterally(L4/5 left:rho < 0.105,P < 0.01;L4/5 right:rho < 0.111,P < 0.01;L5/S1 left:rho 0.128,P < 0.01;L5/S1 right:rho < 0.157,P < 0.001).CONCLUSION Although MRI is the standard imaging tool for diagnosing lumbar spinal stenosis,this study showed only a weak correlation of LRS on MRI and clinical findings.This can be attributed to a number of reasons outlined in this study,underlining that imaging findings alone are not sufficient to establish a reliable diagnosis for patients with LRS.
文摘AIM: To evaluate two simple angle measurements for predicting lumbosacral transitional vertebra (LSTV) in magnetic resonance imaging (MRI) studies of the spine. METHODS: The lumbar spine MRI studies of 50 subjects with LSTV and 50 subjects with normal lumbosacral anatomy were retrospectively evaluated. In each study, the mid-sagittal T2-weighted image was used to measure the angle formed by a line parallel to the superior surface of the sacrum and a line perpendicular to the axis of the scan table (A-angle), as well as the angle formed by a line parallel to the superior endplate of the L3 vertebra and a line parallel to the superior surface of the sacrum (B-angle). RESULTS: The total study population consisted of 100 subjects (46 males, 54 females, 51 ± 16 years old). There were no differences in age and sex between the two groups. Both A-angle and B-angle were significantly increased in subjects with LSTV compared to controls (P < 0.05). The optimal cut-off values of A-angle and B-angle for the prediction of LSTV were 39.8° (sensitivity = 80%, specificity = 80%, accuracy = 83%; 95% confidence interval = 74%-89%, P = 0.0001) and 35.9° (sensitivity = 80%, specificity = 54%, accuracy = 69%; 95% confidence interval = 59%-78%, P = 0.0005), respectively. CONCLUSION: On sagittal MR images of the lumbar spine, an increased A-angle and/or B-angle should alert the radiologist to the presence of LSTV.
文摘AIM: To investigate whether congenital lumbar spinal stenosis(CLSS) is associated with a specific degenerative changes of the lumbar spine. METHODS: The lumbar spine magnetic resonance imaging studies of 52 subjects with CLSS and 48 control subjects were retrospectively evaluated. In each examination, the five lumbar levels were assessed for the presence or absence of circumferential or shallow annular bulges, annular tears, anterior or posterior disc herniations, epidural lipomatosis, Schmorl's nodes,spondylolisthesis, pars defects, and stress reactions of the posterior vertebral elements. RESULTS: Compared to control individuals, subjects with CLSS exhibited increased incidence of circumferential and shallow annular bulges, annular tears, discherniations and spondylolisthesis(P < 0.05). CONCLUSION: CLSS is associated with increased incidence of degenerative changes in specific osseous and soft-tissue elements of the lumbar spine.
文摘BACKGROUND Most cases of Apert syndrome(AS)are found after birth.Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging(MRI)and whole exome sequencing(WES)during pregnancy are rare.CASE SUMMARY We present the case of a 34-year old female patient(gravida 2,para 1)whose fetus was diagnosed with AS during pregnancy.Fetal ultrasound performed at 30,2/7 wk of pregnancy showed abnormalities.MRI and three-dimensional ultrasound performed at 31,1/7 wk of pregnancy showed the possibility of AS.Chromosome examination and core family WES were conducted at 31,5/7 wk of pregnancy.The results showed that FGFR2 in the fetus had a c.755C>G missense mutation in its nucleotide,and AS was confirmed.CONCLUSION This case highlights the importance of imaging examinations.Prenatal ultrasound combined with MRI can identify fetal morphological abnormalities accurately,which can be confirmed by WES.
文摘BACKGROUND The response to axial physiological pressure due to load transfer to the lumbar spine structures is among the various back pain mechanisms.Understanding the spine adaptation to cumulative compressive forces can influence the choice of personalized treatment strategies.AIM To analyze the impact of axial load on the spinal canal’s size,intervertebral foramina,ligamenta flava and lumbosacral alignment.METHODS We assessed 90 patients using three-dimensional isotropic magnetic resonance imaging acquisition in a supine position with or without applying an axial compression load.Anatomical structures were measured in the lumbosacral region from L1 to S1 in lying and axially-loaded magnetic resonance images.A paired t test atα=0.05 was used to calculate the observed differences.RESULTS After axial loading,the dural sac area decreased significantly,by 5.2%on average(4.1%,6.2%,P<0.001).The intervertebral foramina decreased by 3.4%(2.7%,4.1%,P<0.001),except for L5-S1.Ligamenta flava increased by 3.8%(2.5%,5.2%,P<0.001),and the lumbosacral angle increased.CONCLUSION Axial load exacerbates the narrowing of the spinal canal and intervertebral foramina from L1-L2 to L4-L5.Cumulative compressive forces thicken ligamenta flava and exaggerate lumbar lordosis.
文摘Objective: To assess the importance of incidental extraspinal findings on Magnetic Resonance Imaging of the lumbar spine in two hospital facilities. Materials and Methods: It was a descriptive and retrospective study from November 2015 to March 2016. The records of patients who had done a Magnetic Resonance Imaging (MRI) scan of the lumbar spine were re-read in search of incidental findings. The incidental findings found were classified using Colonography Reporting and Data System(C-RADS) classification of extracolonic lesions to assess clinical significance. The prevalence of incidental findings was calculated for each facility, as well as the distribution according to age, the organs involved and the clinical importance. A non-detection rate was calculated by confronting the findings of the study with the original reports. Results: The prevalence of incidental findings was respectively 33% (19 out of 36) in Jordan Medical Center (JMC) in Yaounde and 27.74% (106 out of 292) in Jacques Monod Hospital. The extraspinal incidental findings were classified mainly as extracolonic 2 (E2): 58% in each facility. The percentage detection of incidental findings was 5% at JMS and 1.7% at Jacques Monod Hospital. Conclusion: Extraspinal incidental findings are frequent in both hospitals. However, the rate of detection remains very low.
基金This study was reviewed and approved by the Ethics Committee of the Tokat Gaziosmanpasa University Faculty of Medicine(No.19-KAEK-099).
文摘BACKGROUND Redundant nerve roots(RNRs)of the cauda equina are often a natural evolutionary part of lumbar spinal canal stenosis secondary to degenerative processes characterized by elongated,enlarged,and tortuous nerve roots in the superior and/or inferior of the stenotic segment.Although magnetic resonance imaging(MRI)findings have been defined more frequently in recent years,this condition has been relatively under-recognized in radiological practice.In this study,lumbar MRI findings of RNRs of the cauda equina were evaluated in spinal stenosis patients.AIM To evaluate RNRs of the cauda equina in spinal stenosis patients.METHODS One-hundred and thirty-one patients who underwent lumbar MRI and were found to have spinal stenosis between March 2010 and February 2019 were included in the study.On axial T2-weighted images(T2WI),the cross-sectional area(CSA)of the dural sac was measured at L2-3,L3-4,L4-5,and L5-S1 levels in the axial plane.CSA levels below 100 mm^2 were considered stenosis.Elongation,expansion,and tortuosity in cauda equina fibers in the superior and/or inferior of the stenotic segment were evaluated as RNRs.The patients were divided into two groups:Those with RNRs and those without RNRs.The CSA cut-off value resulting in RNRs of cauda equina was calculated.Relative length(RL)of RNRs was calculated by dividing the length of RNRs at mid-sagittal T2WI by the height of the vertebral body superior to the stenosis level.The associations of CSA leading to RNRs with RL,disc herniation type,and spondylolisthesis were evaluated.RESULTS Fifty-five patients(42%)with spinal stenosis had RNRs of the cauda equina.The average CSA was 40.99±12.76 mm^2 in patients with RNRs of the cauda equina and 66.83±19.32 mm^2 in patients without RNRs.A significant difference was found between the two groups for CSA values(P<0.001).Using a cut-off value of 55.22 mm^2 for RNRs of the cauda equina,sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)values of 96.4%,96.1%,89.4%,and 98.7%were obtained,respectively.RL was 3.39±1.31(range:0.93-6.01).When the extension of RNRs into the superior and/or inferior of the spinal canal stenosis level was evaluated,it was superior in 54.5%,both superior and inferior in 32.8%,and inferior in 12.7%.At stenosis levels leading to RNRs of the cauda equina,29 disc herniations with soft margins and 26 with sharp margins were detected.Disc herniation type and spondylolisthesis had no significant relationship with RL or CSA of the dural sac with stenotic levels(P>0.05).As the CSA of the dural sac decreased,the incidence of RNRs observed at the superior of the stenosis level increased(P<0.001).CONCLUSION RNRs of the cauda equina are frequently observed in patients with spinal stenosis.When the CSA of the dural sac is<55 mm^2,lumbar MRIs should be carefully examined for this condition.
文摘Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people everywhere.Due to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the spine.The semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar diseases.It is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation accuracy.This work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra S1.Pseudo-colour mask images were generated and used as ground truth for training the model.The work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley Data.The proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.
文摘Far lateral lumbar disc herniations(FLLDH)represent a separate category of disc pathology which includes both intraforaminal and extraforaminal lumbar disc herniations,that are characterized by a peculiar clinical presentation,diagnostic and treatment modalities as compared to the more frequent median and paramedian disc hernias.Surgical treatment often represents the only effective weapon for the cure of this disease and over the years different approaches have been developed that can reach the region of the foramen or external to it,with different degrees of invasiveness.The diagnosis is more demanding and still underestimated as it requires a more detailed knowledge in the spine anatomy and dedicated radiological studies.Computerized tomography and in particular magnetic resonance imaging are the appropriate tools for the diagnosis of FLLDH.Despite the widespread use of these diagnostic tests,many cases of FLLDH are overlooked due to insufficiently detailed radiological examinations or due to the execution of exams not focused to the foraminal or the extraforaminal region.Neurophysiological studies represent a valid aid in the diagnostic classification of this pathology and in some cases they can facilitate the differential diagnosis with other types of radiculopathies.In the present study,a comprehensive review of the clinical presentation,epidemiology,radiological study and the neurophysiological aspects is presented.
文摘Because of the small diameter and complex anatomic course of the cranial nerves except for the optic nerve, trigeminal nerve, facial nerve, and cochlear and vestibular nerve, other cranial nerves are difficult to be visualized in magnetic resonance imaging (MRI) scanning with conventional thickness (5-10 mm). With the rapid development of MRI technology high spatial resolution, three-dimensional and two-dimensional magnetic resonance imaging technologies have been used in recent years in the observation of normal and abnormal cranial nerves, including three-dimensional constructive interference in steady state (3D CISS) sequence, three- dimensional magnetization-prepared rapid gradient-echo (3D MP-RAGE) sequence, three-dimensional fast inflow with steady-state precession (3D FISP) seohuence, and some fast spin-echo (FSE) sequences. - Threedimensional fast imaging employing steady-state acquisition (3D-FIESTA) is a fast three-dimensional steady-state imaging sequence with high spatial resolution and contrast between the organizational structures. And this sequence was reportedly used in the study on the diseases in the cerebellopontine angle; inner ear and posterior fossa tumors.7'8 However, the reports about the value of 3D-FIESTA sequence for the visualization of normal cranial nerves are still rare.
基金supported financially by grants from the National Natural Science Foundation of China(No.81771793).
文摘Objective This study aimed to develop and test a model for predicting dysthyroid optic neuropathy(DON)based on clinical factors and imaging markers of the optic nerve and cerebrospinal fluid(CSF)in the optic nerve sheath.Methods This retrospective study included patients with thyroid-associated ophthalmopathy(TAO)without DON and patients with TAO accompanied by DON at our hospital.The imaging markers of the optic nerve and CSF in the optic nerve sheath were measured on the water-fat images of each patient and,together with clinical factors,were screened by Least absolute shrinkage and selection operator.Subsequently,we constructed a prediction model using multivariate logistic regression.The accuracy of the model was verified using receiver operating characteristic curve analysis.Results In total,80 orbits from 44 DON patients and 90 orbits from 45 TAO patients were included in our study.Two variables(optic nerve subarachnoid space and the volume of the CSF in the optic nerve sheath)were found to be independent predictive factors and were included in the prediction model.In the development cohort,the mean area under the curve(AUC)was 0.994,with a sensitivity of 0.944,specificity of 0.967,and accuracy of 0.901.Moreover,in the validation cohort,the AUC was 0.960,the sensitivity was 0.889,the specificity was 0.893,and the accuracy was 0.890.Conclusions A combined model was developed using imaging data of the optic nerve and CSF in the optic nerve sheath,serving as a noninvasive potential tool to predict DON.
基金Supported by Key Project of Jiangxi Provincial Youth Science Foundation:to Explore the Analgesic Mechanism of Brain Functional Network Regulation of moxibustion on Heat-sensitive Acupoints Based on rfMRI and MRS(No.20192ACB21007)Jiangxi Province Introduces and Cultivates Innovative and Entrepreneurial High-level Talent Projects:Brain Functional Network Regulation and Neurobiochemical Mechanism of Heat-sensitive Moxibustion Analgesia(No.jxsq2019201104)。
文摘We want to explore the analgesic brain effect of the moxibustion at heat-sensitized Yaoyangguan(GV3)in patients with lumbar disc herniation(LDH)and myofascial pain syndrome(MPS).In an assessor-blinded observational study,we will include 15 LDH and 15 MPS.They will accept same treatment of heat-sensitive moxibustion at Yaoyangguan(GV3).The resting-state functionality magnetic resonance imaging image data of brain activities before and after treatment will be analyzed by mean fractional amplitude of low-frequency fluctuation,regional homogeneity analysis and brain functional connection.We select seed of first sensory cortex,second sensory cortex,insula cortex,periaqueductal gray and anterior cingulate cortex as the regions of interest to analyse the relationship between brain functional connectivity of pain-related networks and clinical data.Our study could disclose key brain targets and central response characteristics of the analgesic brain effect and the brain functional connection of heat-sensitive moxibustion.
文摘Magnetic Resonance Elastography (MRE) is a noninvasive technique to measure elas-ticity of tissues in vivo. In this paper, a mechanical shear wave MR imaging system experiment is set for MRE. A novel actuator is proposed to generate me-chanical shear waves propagating inside a gel phantom. The actuator is made of piezoelectric ce-ramics, and fixed on a plexiglass bracket. Both of the gel phantom and the actuator are put into a head coil inside the MR scanner’s bore. The actuator works synchronously with an MR imaging sequence running on the MR scanner. The sequence is modified from a FLASH sequence into a motion-sensitizing phase- contrast sequence for shear wave MR imaging. Shear wave images are presented, and these effects on the shear wave MR imaging system, including the stiffness of phantoms, the frequency of the actuator, the parameters of the motion-sensitizing gradient, and the oscillation of the patient bed, are discussed.
基金This study was supported by a grant from the Natural Science Foundation of Fujian Province (No. 2004Y008).
文摘Background Detection rate of retropharyngeal lymph node metastasis in patients with nasopharyngeal carcinoma (NPC) needs to be improved. The purpose of this study was to compare three magnetic resonance (MR) sequences for detecting lymph nodes in patients with NPC. Methods Between July 2007 and March 2008, MR staging of pre-treated tumor was conducted on 120 patients with pathologically confirmed NPC. The outcome of three different sequences for MR NPC staging were compared: coronal short T1 inversion recovery (STIR), axial proton density fat-suppressed (PDWI fs), and coronal contrast enhanced fast spin echo T1 weighted fat-suppressed (CE FSE TlWl fs). Nodal classification method (1999) was applied to count the number of retropharyngeal and cervical lymph nodes discovered by each MR sequence. Paired t tests were used for statistical analysis. Results A total of 2575 lymph nodes were found using coronal STIR sequence; 1816 lymph nodes for coronal CE FSE TIWI fs sequence and 2638 lymph nodes for axial PDWl fs sequence. Significant differences existed in the number of lymph nodes detected by axial PDWI fs and coronal CE FSE T1WI fs sequence (paired t test, P 〈0.05), with the former sequence getting higher numbers. Statistical differences also existed between coronal STIR and coronal CE FSE TlWl fs sequence (paired ttest, P 〈0.05), with the former sequence getting higher numbers. No significant difference was found between coronal STIR sequence and axial PDWI fs sequence (paired ttest, P 〉0.05). Conclusions For the detection of retropharyngeal and cervical lymph nodes, coronal STIR sequence and axial PDWI fs sequence have similar performance and both sequences showed better detection than CE FSE TIWI fs sequence. Furthermore, by combining coronal STIR sequence and axial PDWI fs sequence, we can improve the detection of lymph nodes in NPC N-staging before treatment, especially for lymph nodes located in the thoracic entrance.
文摘Fat-suppression technology of magnetic resonance is very important in clinical practice.This article is written to interpret the principle, advantages/disadvantages and clinical applications of some regular fat-suppression sequences in the diagnosis of Bone-Joint Disease, including 1) frequency-selective saturation (FS);2) short-TI inversion recovery (STI-R);3)frequency selective inversion pulse;4) fat suppression water or fat selective excitation technique;5) Dixon technology and 6) magnetization transfer contrast (MTI).
文摘The purpose of this study was to analyze the lesion brightness (image contrast) in multiple MRI sequences in patients with relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), primary progressive MS (PPMS), and clinically isolated syndrome (CIS);and to correlate the lesion contrast with lesion volumes and neurological disability. MRI ex- amination at 1.5 T was performed on 80 patients with RRMS, SPMS, PPMS, or CIS. The protocol included T1- and T2-weighted spin echo (SE), fluid attenuated inversion recovery (FLAIR), T1-weighted SE with magnetization transfer preparation, and diffusion weighted imaging (DWI). Contrast was measured between MS lesions and normal appearing white matter. Lesion volume was calculated in T1-weighted- and FLAIR-images. All patients were examined neurologically including evaluation of expanded disability status scale (EDSS) score. Lesion contrast correlated with total brain lesion volume (p = 0.000 - 0.040). In patients with low EDSS, three sequences were able to differentiate between CIS and RRMS. SPMS and PPMS were separated by DWI. Lesion contrast correlated with EDSS score on T1-weighted imaging, with or without magnetization transfer preparation. Patient age correlated with lesion contrasts. Contrast measurements seem limited in radiological and clinical diagnosis of MS in reference to disease course, its activity and progression. The differentiation between MS subgroups might improve at 3 T and could help in leading to earlier treatment of the disease.
文摘Purpose:To preliminarily investigate the application value of rapid sequences FFE and SSh-TSE in ocular magnetic resonance imaging(MRI).Methods:Ocular MRI was performed in 18 subjects without ocular conditions,and demonstration of 15 delicate anatomic structures on two sequences in each subject was rated by three proficient physicians.Results:FFE sequence was comparatively advantageous in demonstrating delicate structures on ocular wall and ocular adnexa(P<0.001) over SSh-TSE;while SSh-TSE sequence better revealed the delicate anatomy within anterior chamber(P<0.001) and optic nerve sheath(P<0.05),with statistically significant differences compared with FFE.Conclusion:Optimized FFE and SSh-TSE sequences are able to effectively eliminate the impact from motion artifact and thus result in desirable images with high spatial resolution.The application of high-resolution MR microscopic imaging technique has improved the ability to demonstrate delicate ocular structures.