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find Keyword "MRI" 95 results
  • DISTRIBUTION CHARACTERISTICS OF MODIC CHANGES OF LUMBAR ENDPLATE AND ITS RELATIONSHIP WITH LOW BACK PAIN

    Objective To investigate the incidence of Modic changes of lumbar endplate and its cl inical significances. Methods The imaging data of 562 patients (2 810 lumbar intervertebral discs) with lumbar degenerative disease undergoingposterior operation from June 2006 to June 2009 were retrospectively reviewed. There were 297 males and 265 femalesaged 26-77 years old (average 49 years old). The course of disease was 2 months to 40 years (median 10.4 years). Imaging examinations excluded the tuberculosis, cancer, infection, trauma, etc. The association of Modic changes with low back pain (LBP) and patients’ weight was analyzed according to the incidence and types of Modic changes as well as the distribution of gender, age and disc level through imaging data of MRI. Results Modic changes were observed in 106 patients (18.9%) of 113 intervertebral discs, including 40 (13.5%) males and 66 (24.9%) females. The difference between male proportion and female proportion had a significant difference (P lt; 0.05). Modic changes was distributed from age 26 to 77 years old (average 49 years old). Among all the patients, 33 cases (5.9%) were type I, 66 cases (11.7%) were type II, and 7 cases (1.2%) were type III. According to the segment, the lesions involved L5, S1 disc for 58 discs (51.3%), L4, 5 for 35 (31.0%), L3, 4 for 11 (9.7%), L2, 3 for 6 (5.3%), and L1, 2 for 3 (2.7%). The incidence of Modic change was 15.5% (41/264) in the normal body weight group, 16.3% (34/208) in the over-weight group, and 34.4% (31/90) in the obesity group. There was a significant association between obesity and the Modic change (P lt; 0.05). Preoperatively, there were 59 patients (55.7%) with LBP in the Modic group, including 27 cases of type I Modic change, 27 cases of type II Modic change, and 5 cases of type III Modic change. Postoperatively, the LBP of 40 patients (67.8%) were rel ieved, including 24 cases of type I Modic change, 14 cases of type II Modic change, and 2 cases of type III Modic change. In non-Modic change group, there were 126 patients (27.6%) with LBP preoperatively, and 96 patients (76.2%) eased the symptoms postoperatively. There was significant difference between two groups on incidence rate (P lt; 0.05),but no significant difference on the remission rate of LBP (P gt; 0.05). Conclusion The most common Modic change is typeII and the most frequently involved level is the L5, S1. Modic changes are more common in female than in male and mainly happen to the obesity group. The incidence of LBP is higher in the patients with Modic change.

    Release date:2016-09-01 09:08 Export PDF Favorites Scan
  • SIGNIFICANCE OF BNIP3 GENE EXPRESSION AND CELL APOPTOSIS IN NUCLEUS PULPOSUS OF DEGENERATIVE INTERVERTEBRAL DISC IN RABBITS

    Objective To detect the cell density, apoptotic rate, and the expressions of BNIP3 in nucleus pulposus of degenerative intervertebral disc of rabbits, so as to further understand the mechanism of intervertebral disc degeneration. Methods Thirty male New Zealand white rabbits, aging 3 months and weighing (2.3 ± 0.2) kg, were divided into sham operation group (control group, n=10) and intervertebral disc degeneration model group (experimental group, n=20). Interbertebral disc degeneration models were establ ished by puncture of L3,4, L4,5, and L5,6 intervertebral discs in the experimental group; intervertebral discs were exposed only and then sutured in the control group. The degree of intervertebral disc degeneration was evaluated according to Pfirrmann classification by MRI at 4 and 8 weeks after establ ishing models. Apototic cells were determined by TUNEL and histological methods, and the immunohistochemical staining was performed to detect the expressions of BNIP3 in nucleus pulposus of intervertebral disc. Results MRI examination showed that the signal intensity decreased gradually at 4 and 8 weeks in the experimental group. There wassignificant difference in the degree of intervertebral disc degeneration between at 4 weeks and at 8 weeks in the experimental group (P lt; 0.05). The histological observation and TUNEL test showed that high density of nucleus pulposus cells and only a few apoptotic cells were observed in the control group; at 4 and 8 weeks, the density of nucleus pulposus cells decreased gradually with more apoptotic cells in the experimental group. There were significant differences in the nucleus pulposus cell density and positive rate of TUNEL staining between 2 groups, and between at 4 weeks and at 8 weeks in the experimental group (P lt; 0.05). The expression of BNIP3 of nucleus pulposus was negative in the control group; however, in the experimental group, the positive expression rates of BNIP3 of nucleus pulposus (the gray values) were 13.45% ± 1.16% and 32.00% ± 1.82% (194.32 ± 4.65 and 117.54 ± 2.11) at 4 and 8 weeks respectively, showing significant differences (P lt; 0.05). Conclusion The decrease of cell density in nucleus pulposus is involved in the development of intervertebral disc degeneration. Cell apoptosis is one of reasons in the decrease of nucleus pulposus cell; BNIP3 is involved in nucleus pulposus cell apoptosis in the degenerative intervertebral disc.

    Release date:2016-09-01 09:04 Export PDF Favorites Scan
  • FACTORS TO AFFECT SEVERITY OF HYPEREXTENSION INJURY OF CERVICAL SPINAL CORD

    Objective To explore the factors to affect severity of hyperextension injury of the cervical spinal cord (HEICSC). Methods Forty-five patients with HEICSC, 35 males and 10 females, aged 27-67 years old (mean 48.2 years old), were retrospectively analyzed. The disease course was 30 minutes to 16 days. According to modified Frankel grading, there were 6 cases of grade A, 8 cases of grade B, 16 cases of grade C and 15 cases of grade D. Spinal cord injuries (SCI) segments were determined according to SCI plane and high signal change (HSC) in spinal cord on MR images. The whole or large part of HSC segments were supposed to be main injured spinal cord segments (MISCSs) and the staccato or patchy HSC ones were supposed to be common injured spinal cord segments (CISCSs). When the external force acting on head or face suffered was larger, the force produced during high-speed movement or forehead and/or face had severe contused and/or) lacerated wound, the force was defined severe traumatic strength, whereas the reverse was true for sl ight traumatic strength. According to signal magnitude of the cervical discs on T2-weighted MR images, degeneration of cervical discs and cervical vertebras were classified into 5 grades: grade 0-4. Cervical spinal stenosis were graded to 5 grades according to the width of anterior or posterior cerebrospinal fluid layer to spinal cord on T2-weighted MR images and compressed degree of spinal cord on T1-weighted MR images. The influence of traumatic strength, cervical spinal degeneration or cervical spinal stenosis on SCI were explored. Results Among the 45 cases, 12 cases were caused by sl ight traumatic strength, 33 cases were caused by severe one. The cervical spinal cord was injuried more sl ightly and the patients were older in the sl ight traumatic strength cases than in the severe ones (P lt; 0.05). The number of MISCSs were 45 in 40 cases and the 25 segments were located at C3, 4 level. The number of CISCSs were 39 in 21 cases. All the cervical vertebraes of the 45 patients had degenerated. The most were in grade 3 in 22 patients and the severest degenerative segments were mostly located in C5,6 discs in 35 ones. The number of the MISCSs in different degenerative grades of discs was 0 in grade 0, 9 in grade 1, 20 in grade 2, 14 in grade 3, and 2 in grade 4. The ratios of the segment number of injuried spinal cord to the segment number of spinal stenosis in every grade of stenosis were 1/62 in grade 0, 2/11 in grade 1, 27/52 in grade 2, 33/33 in grade 3, 21/22 in grade 4. Conclusion Three main factors including the magnitude of traumatic strength, the degree of instabil ity of cervical vertebrae and the degree of cervical stenosis contribute to development and progress of HEICSC.

    Release date:2016-09-01 09:08 Export PDF Favorites Scan
  • Pancreatic neuroendocrine neoplasm: current status and advancement in imaging

    ObjectiveTo summarize the status and progress of imaging studies of pancreatic neuroendocrine neoplasms (pNENs).MethodThe relevant literatures published recently at domestic and abroad about the imaging of pNENs were collected and reviewed.ResultsDue to poor visibility of pancreatic body and tail, the application of ultrasound (US) was limited. Compared with US, endoscopic ultrasound (EUS) and contrast-enhanced ultrasound (CEUS) could improve the detection rate of pNENs. The ability of plain CT scans to differentiate pathological grades was still controversial, but the value of enhanced scan was higher. CT texture analysis was feasible in the discrimination of nonhypervascular pNENs and pancreatic ductal adenocarcinoma (PDAC). Teta2 was the parameter with the highest diagnostic performance. The enhanced features of MRI were similar to CT. Combined with the apparent diffusion coefficient (ADC) value, the diagnostic and classification capabilities of MRI were improved, and the sensitivity and specificity of different ADC thresholds were also different. 68Ga-tetraazacyclododecane tetraacetic acid (68Ga-DOTA) peptide PET-CT had good preliminary diagnostic value for well-differentiated pNENs, and 18Fluoro-fluorodeoxyglucose (18F-FDG) PET-CT had limited diagnostic value.ConclusionsSomatostatin receptor imaging is of high diagnostic value and can guide clinical treatment and predict prognosis, but it has not been widely used in China. Conventional morphological images have advantages in the diagnosis and classification of pNENs. Therefore, it is important to choose a proper image inspection method.

    Release date:2020-04-28 02:46 Export PDF Favorites Scan
  • Research progress of lateral femoral notch sign in diagnosis of anterior cruciate ligament rupture

    ObjectiveTo summarize the relationship between lateral femoral notch sign (LFNS) and anterior cruciate ligament (ACL) rupture. MethodsThe relevant literature of LFNS at home and abroad in recent years was retrospectively reviewed, and its mechanism, diagnostic criteria and influencing factors in diagnosis of ACL rupture were summarized and analyzed.ResultsThe LFNS is associated with rotational stability of the knee. As an indirect sign of ACL rupture, the LFNS has high clinical diagnostic value, especially the diagnosis of ACL rupture with lateral meniscus injury.ConclusionThe diagnostic criteria and influencing factors of LFNS in diagnosis of ACL rupture are still unclear and controversial, which needs further study.

    Release date:2021-09-28 03:00 Export PDF Favorites Scan
  • MAGNETIC RESONANCE IMAGING AND PATHOLOGICAL EVALUATION OF VACUUM SEALING DRAINAGE EFFICACY OF EARLY TREATED LIMB GUNSHOT

    Objective Gunshot wound spreads to the surrounding tissues and organs, it is difficult to debride and easy to infect. The conventional treatment is thorough, extensive debridement, fully open drainage, which often causes normal tissue damage and compl ications. To evaluate the effectiveness of vacuum seal ing drainage (VSD) treating thepenetrating wound in porcine extremity by MRI and pathological methods so as to provide theoretical basis for future cl inical use. Methods Eight healthy adult pigs, weighing (45 ± 5) kg, were selected. Eight pairs of hind l imb penetrating wounds (16 wounds) were made by using Chinese-made 95-type rifle at 25 meters distance, which were randomly divided into experimental group (left side, n=8) and the control group (right side, n=8). After debriding and disinfecting the penetrating wounds at 6 hours after injury, wounds were treated with VSD in experimental group. The ball istics exports of the wounds were covered with single-layer gauze and imports were directly sutured and covered with sterile gauze in control group. The trajectory and the general condition of the adjacent skin were observed. MRI and histological observation were taken at 5, 24, 48, and 72 hours after injury, bacterial counting analysis was done at 0, 12, 24, 48, and 72 hours after injury. Results The aperture of the trajectory exit and entry were (5.00 ± 2.50) cm and (0.30 ± 0.15) cm immediately after injury. The wound surface was clean, rosy without leakage and swell ing after 72 hours in experimental group; wound and adjacent tissue were swell ing obviously, pus, muscle necrosis and exfol iative tissue was observed, and deep defect cavity at the trajectory exit could be seen in control group. MRI showed that pairs of l inear low signal in T1WI and T2WI was seen in trajector of experimental group at 5 hours after injury, and signal in T1WI gradually increased at disrupted area and tissue deformation area at 24, 48, and 72 hours; in control group, low signal in T1WI was observed at 5 hours after injury, and signal in T2WI gradually increased and a clear boundari between edema and surrounding tissue, and the increase of signal in T1WI was not obvious at 24, 48, and 72 hours. The histological observation showed that wound was dominated by effusion at 5 hours after injury, granulation tissue gradually increased, muscle tissue dissolved and inflammatory cell infiltration was not obvious at 24, 48, and 72 hours in experimental group; in control group, the gradual dissolution of muscle fibers and inflammatory cell infiltration were observed at 5, 24, and 48 hours, muscle tissue became swell ing, dissolving and degeneration and a large number of inflammatory cell infiltration gathered into the bacteria group at 72 hours. There was no significant difference in the number of bacteria per gram of tissue (P gt; 0.05) between experimental group and control group at 0 hour after injury; the numbers of bacteria in control group were significantly higher than those in experimental group at 12, 24, 48, and 72 hours (P lt; 0.05). Conclusion MRI combined with pathology show diagnostic meaning in treatment of gunshot wound with VSD. MRI can accurately reflect the scope of l imb gunshot wound 72 hours after injury. VSD may be an approach to delay infective time, shorten wound heal ing time, and promote the growth of healthy granulation tissue.

    Release date:2016-08-31 05:47 Export PDF Favorites Scan
  • Study on the evaluation of glenoid bone defects by MRI three-dimensional reconstruction

    Objective To investigate the feasibility of MRI three-dimensional (3D) reconstruction model in quantifying glenoid bone defect by comparing with CT 3D reconstruction model measurement. Methods Forty patients with shoulder anterior dislocation who met the selection criteria between December 2021 and December 2022 were admitted as study participants. There were 34 males and 6 females with an average age of 24.8 years (range, 19-32 years). The injury caused by sports injury in 29 cases and collision injury in 6 cases, and 5 cases had no obvious inducement. The time from injury to admission ranged from 4 to 72 months (mean, 28.5 months). CT and MRI were performed on the patients’ shoulder joints, and a semi-automatic segmentation of the images was done with 3D slicer software to construct a glenoid model. The length of the glenoid bone defect was measured on the models by 2 physicians. The intra-group correlation coefficient (ICC) was used to evaluate the consistency between the 2 physicians, and Bland-Altman plots were constructed to evaluate the consistency between the 2 methods. Results The length of the glenoid bone defects measured on MRI 3D reconstruction model was (3.83±1.36) mm/4.00 (0.58, 6.13) mm for physician 1 and (3.91±1.20) mm/3.86 (1.39, 5.96) mm for physician 2. The length of the glenoid bone defects measured on CT 3D reconstruction model was (3.81±1.38) mm/3.80 (0.60, 6.02) mm for physician 1 and (3.99±1.19) mm/4.00 (1.68, 6.38) mm for physician 2. ICC and Bland-Altman plot analysis showed good consistency. The ICC between the 2 physicians based on MRI and CT 3D reconstruction model measurements were 0.73 [95%CI (0.54, 0.85)] and 0.80 [95%CI (0.65, 0.89)], respectively. The 95%CI of the difference between the two measurements of physicians 1 and 2 were (–0.46, 0.49) and (–0.68, 0.53), respectively. Conclusion The measurement of glenoid bone defect based on MRI 3D reconstruction model is consistent with that based on CT 3D reconstruction model. MRI can be used instead of CT to measure glenoid bone defects in clinic, and the soft tissue of shoulder joint can be observed comprehensively while reducing radiation.

    Release date:2023-05-11 04:44 Export PDF Favorites Scan
  • An MRI study of lateral vascular safety zones in oblique lumbar interbody fusion surgery

    ObjectiveTo study the anatomical characteristics of blood vessels in the lateral segment of the vertebral body through the surgical approach of oblique lumbar interbody fusion (OLIF) using MRI imaging, and evaluate its potential vascular safety zone. Methods The lumbar MRI data of 107 patients with low back and leg pain who met the selection criteria between October 2019 and November 2022 were retrospectively analyzed. The vascular emanation angles, vascular travel angles, and the length of vessels in the lateral segments of the left vertebral body of L1-L5, as well as the distance between the segmental vessels in different Moro junctions of the vertebral body and their distances from the edges of the vertebrae in the same sequence (bottom marked as I, top as S) were measured. The gap between the large abdominal vessels and the lateral vessels of the vertebral body was set as the lateral vascular safe zones of the lumbar spine, and the extent of the safe zones (namely the area between the vessels) was measured. The anterior 1/3 of the lumbar intervertebral disc was taken as the simulated puncture center, and the area with a diameter of 22 mm around it as the simulated channel area. The proportion of vessels in the channel was further counted. In addition, the proportions of segmental vessels at L5 without a clear travel and with an emanation angel less than 90° were calculated. Results Except for the differences in the vascular emanation angles between L4 and L5, the vascular travel angles between L1, L2 and L4, L5, and the length of vessels in the lateral segments of the vertebral body among L1-L4 were not significant (P>0.05), the differences in the vascular emanation angles, vascular travel angles, and the length of vessels between the rest segments were all significant (P<0.05). There was no significant difference in the distance between vessels of L1, L2 and L2, L3 at Moro Ⅰ-Ⅳ junctions (P>0.05), in L3, L4 and L4, L5 at Ⅱ and Ⅲ junction (P>0.05). There was no significant difference in the vascular distance of L2, L3 between Ⅱ, Ⅲ junction and Ⅲ, Ⅳ junction, and the vascular distance of L3, L4 between Ⅰ, Ⅱ junction and Ⅲ, Ⅳ junction (P>0.05). The vascular distance of the other adjacent vertebral bodies was significant different between different Moro junctions (P<0.05). Except that there was no significant difference in the distance between L2I and L3S at Ⅰ, Ⅱ junction, L3I and L4S at Ⅱ, Ⅲ junction, and L2I and L3S at Ⅲ, Ⅳ junction (P>0.05), there was significant difference of the vascular distance between the bottom of one segment and the top of the next in the other segments (P<0.05). Comparison between junctions: Except for the L3S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ junction, and L5S between Ⅰ, Ⅱ junction and Ⅱ, Ⅲ and Ⅲ, Ⅳ junctions had no significant difference (P>0.05), there were significant differences in the distance between the other segmental vessels and the vertebral edge of the same sequence in different Moro junctions (P<0.05). The overall proportion of vessels in the simulated channels was 40.19% (43/107), and the proportion of vessels in L1 (41.12%, 44/107) and L5 (18.69%, 20/107) was higher than that in the other segments. The proportion of vessels in the channel of Moro zone Ⅰ (46.73%, 50/107) and zone Ⅱ (32.71%, 35/107) was higher than that in the zone Ⅲ, while no segmental vessels in L1 and L2 were found in the channel of zone Ⅲ (χ2=74.950, P<0.001). Moreover, 26.17% (28/107) of the segmental vessels of lateral L5 showed no movement, and 27.10% (29/107) vascular emanation angles of lateral L5 were less than 90°. Conclusion L1 and L5 segmental vessels are most likely to be injured in Moro zones Ⅰ and Ⅱ, and the placement of OLIF channels in L4, 5 at Ⅲ, Ⅳ junction should be avoided. It is usually safe to place fixation pins at the vertebral body edge on the cephalic side of the intervertebral space, but it is safer to place them on the caudal side in L1, 2 (Ⅰ, Ⅱ junction), L3, 4 (Ⅲ, Ⅳ junction), and L4, 5 (Ⅱ, Ⅲ, Ⅳ junctions).

    Release date:2023-09-07 04:22 Export PDF Favorites Scan
  • VALUE OF MRI IN DIAGNOSIS OF OBSTETRICAL BRACHIAL PLEXUS PALSY PRE-GANGLIONIC INJURY

    Objective To evaluate the value of MRI in diagnosis of obstetrical brachial plexus palsy pre-gangl ionic injury. Methods From November 2006 to February 2008, 10 patients with obstetrical brachial plexus palsy were treated, 8 males and 2 females, aged from 2 months to 3 years (11.4 months on average). There were 7 cases of left side and 3 of right side.According to Tassin classification, 2 cases were type II, 6 type III and 2 type IV. All patients were performed MRI examinations before the operation, whose results were compared with those of exploration during the operation. Results MRI examinations showed 1 patient was normal and 9 patients had post-traumatic spinalmeningolcele. The 6 patients had displacement of spinal cord (4 towards the healthy side and 2 towards the sick side), 6 had deformity of spinal cord, and 2 had avulsed nerve root thickening. MRI detected 19 nerve roots were positive, 16 were true positive and 3 false positive in surgical exploration. MRI detected 6 nerve roots were negative, 4 were true negative and 2 false negative in surgical exploration. The sensitivity, specificity and accuracy of MRI in diagnosis of obstetrical brachial plexus palsy pre-gangl ionic injury were 84.2%, 80.0% and 83.3%, respectively. There were significant differences in the results by preoperative MRI examinations and by exploration during the operation (P lt; 0.05). Conclusion MRI can show pre-gangl ionic injury of brachial plexus of the patients with obstetrical brachial plexus palsy and can supply references for early diagnosis and operation time. MRI can be routinely conducted as a preoperative examination.

    Release date:2016-09-01 09:19 Export PDF Favorites Scan
  • Comparative Study of Quantitative Diagnosis of Hepatic Fat Content by MRI and Patholgy

    ObjectiveTo investigate the diagnostic value of spectral saturation inversion recovery, gradient-echo chemical shift MRI, and proton magnetic resonance spectroscopy in quantifying hepatic fat content. MethodsConventional T1-weighted and T2-weighted scanning (without fat saturation and with fat saturation), gradient-echo T1W in-phase (IP) and opposedphase (OP) images and 1H-MRS were performed in 31 healthy volunteers and 22 patients who were candidates for liver surgery. Signal intensities of T1WI amp; T1WIFS (SInonfat1, SIfat1), T2WI amp; T2WI-FS (SInonfat2, SIfat2), and IP amp; OP (SIin, SIout) were measured respectively, the relative signal intensity one (RSI1), relative signal intensity two (RSI2), and fat index (FI) were calculated. Peak values and the area under peak of 1H-MRS were measured, and the relative lipid content of liver cells (RLC ) were calculated. Twenty-two patients accepted liver resection and histological examination after MRI scanning, the proportion of fatty degenerative cells were calculated by image analysis software. Results①Hepatic steatosis group showed higher average values of RSI1, FI, and RLC to non-hepatic steatosis group (Plt;0.05), while there was no significant difference in RSI2 between two groups (Pgt;0.05). ②There was a statistical significant difference in RLC among different histopathological grades of hepatic steatosis, and RLC increased in parallel with histopathological grade (Plt;0.05).There was no significant difference in RSI2, RSI1, and FI among different histopathological grades, although the latter two had a tendency of increasing concomitant with histopathological grade (Pgt;0.05). ③The values of FI and RLC were positively correlated with the PFDC (r=0468, P=0.027; r=0771, Plt;0.000 1), while they were not in RSI1 and RSI2 (r=0.411, P=0.057; r=0.191, P=0.392). ConclusionsSPIR, Gradient-echo chemical shift MRI and 1H-MRS can help to differentiate patients with hepatic steatosis from normal persons, the latter also can help to classify hepatic steatosis. In quantifying hepatic fat content, 1H-MRS is superior to gradient-echo chemical shift MRI, while SPIR’s role is limited.

    Release date:2016-09-08 10:41 Export PDF Favorites Scan
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