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find Keyword "tensor" 34 results
  • An Improved Spectral Quaternion Interpolation Method of Diffusion Tensor Imaging

    Diffusion tensor imaging (DTI) is a rapid development technology in recent years of magnetic resonance imaging. The diffusion tensor interpolation is a very important procedure in DTI image processing. The traditional spectral quaternion interpolation method revises the direction of the interpolation tensor and can preserve tensors anisotropy, but the method does not revise the size of tensors. The present study puts forward an improved spectral quaternion interpolation method on the basis of traditional spectral quaternion interpolation. Firstly, we decomposed diffusion tensors with the direction of tensors being represented by quaternion. Then we revised the size and direction of the tensor respectively according to different situations. Finally, we acquired the tensor of interpolation point by calculating the weighted average. We compared the improved method with the spectral quaternion method and the Log-Euclidean method by the simulation data and the real data. The results showed that the improved method could not only keep the monotonicity of the fractional anisotropy (FA) and the determinant of tensors, but also preserve the tensor anisotropy at the same time. In conclusion, the improved method provides a kind of important interpolation method for diffusion tensor image processing.

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  • DYNAMIA CORRECTION OF HALLUX VALGUS DEFORMITY WITH MUSCULUS EXTENSOR HALLUCIS LONGUS SHIFTING

    Objective To discuss the mechanisms and clinical effect of musculus extensor hallucis longus shifting in correcting hallux valgus (HV) deformity. Methods From April 2004 to December 2006,25 cases of HV (38 feet) were treated by musculus extensor hallucis longus shifing. There were 2 men and 23 women, aging from 22-60 years (mean 46.3 years).HV angle was 21.45° (mean 31.30°), intermetatarsal(IM) angle was 7-21° (mean 12.52°). The HV were corrected by cutting osteophyma of the first metatarsal bone, cutting transverse head of adductor pollicis, transferring musculus extensor hallucis longus and reconstructing its insertion. Results The patients were followed up 6-14 months after operation. HV angle and IM angle were 7.30°±2.62° and 6.50°±2.46° respectively, showing significantdifferences when compared with before operation (Plt;0.05). According to the American Orthopaedic Foot amp; Ankle Society (AOFAS) score system, the foot function was excellent in 25 feet, good in 7 feet and poor in 6 feet,and the excellent and good rate was 84.2%. Hallux varus occurred in 2 feet after 2 months of operation, metatarsophalangeal joint limitation of motion in 2feet after 3 months of operation, no HV recurred. ConclusionThe HV deforemity can be corrected by shifting the musculus extensor hallucis longus and reconstructing its insertion. It makes stress of metatarsophalangeal joint balance and prevent recurrance of HV deformity.

    Release date:2016-09-01 09:20 Export PDF Favorites Scan
  • EFFECTIVENESS OF MODIFIED EXTENSOR INDICIS PROPRIUS TENDON TRANSFER FOR RECONSTRUCTION OF SPONTANEOUSLY RUPTURED EXTENSOR POLLICIS LONGUS TENDON

    ObjectiveTo investigate the effectiveness of modified extensor indicis proprius (EIP) tendon transfer for reconstruction of spontaneously ruptured extensor pollicis longus (EPL) tendon by comparing with the traditional EIP tendon transfer. MethodsBetween January 2009 and December 2011, 11 cases of spontaneously ruptured EPL tendon were treated by modified EIP tendon transfer to reconstruct extension function (modified group). On the base of traditional procedure, the proximal end of EPL tendon was sutured with EIP tendon and the distal end of EIP tendon was crossed round extensor pollicis brevis (EPB) tendon and sutured back with EPL tendon. A specific EI-EPL evaluation method (SEEM) was used to measure the EPL tendon function after transfer. The result was compared with that of the other 18 cases undergoing traditional operation (traditional group). There was no significant difference in gender, age, disease duration, and injury causes between 2 groups (P gt; 0.05). ResultsAll incisions healed by first intention. In traditional group, 5 cases were out of follow-up, and the other 24 cases were followed up 1 year and 6 months on average (range, 8 months-2 years and 6 months). At the last follow-up, according to the evaluation of SEEM, the thumb elevation and flexion deficits of modified group were significantly less than those of traditional group (P lt; 0.05). The independent elevation deficit of the index finger of modified group was similar to that of traditional group (P gt; 0.05). The effectiveness was excellent in 9 cases and good in 2 cases with an excellent and good rate of 100% in modified group, and was excellent in 5 cases, good in 6 cases, and fair in 2 cases with an excellent and good rate of 84.6%. The effectiveness of modified group was significantly better than that of traditional group (χ2=0.03, P=0.03). ConclusionReconstruction of EPL tendon function by modified EIP tendon transfer is effective and easy. It can increase strength of the transferred tendon and obtain satisfactory results, but the long-term effectiveness needs further follow-up.

    Release date:2016-08-31 05:39 Export PDF Favorites Scan
  • THE EFFECT OF REPAIR OF PARATENDON IN TENDON HEALING

    In order to investigate the effect of repair of paratendon in tendon healing, two different ways were performed to repair the transected extensor tendons of chick’s toe. End to end suture of the extensor tenon was performed in group 1 while the paratendon was also repaired simultaneously in addition to suture of the tendon in group 2. Gross observation and histological examination were undertaken in the 3rd and 6th week after operation. The result showed, in group 1, extensive adhesion and irregular proliferation of fibroblasts was found in the 3rd week, severe adhesion and irregular arrangement of fibroblasts with less collagen fiber was found in the 6th week; while in group 2, smooth and regular "fusiform structure" was formed, slight adhesion and regular proliferation of fibroblasts were found in the 3rd week, adhesion disappeared and the structure of paratendon and tondon recovered in the 6th week. It was concluded that repair of extensor tendon and paratendon simultaneously could promote the intrinsic tendon healing and prevent tendon adhesion.

    Release date:2016-09-01 11:08 Export PDF Favorites Scan
  • Structural abnormalities of default mode network in childhood absence epilepsy revealed by diffusion tensor imaging

    ObjectiveChildhood absence epilepsy (CAE) is a common syndrome of idiopathic generalized epilepsy.However, little is known about the brain structural changes in this type of epilepsy, especially in the default mode network (DMN) regions.Diffusion tensor imaging (DTI) is a noninvasive techniques that can be used to quantitatively explore structural characteristics of brain.This study aims at using the DTI technique to quantify structural abnormalities of DMN nodes in CAE patients.MethodDTI data were obtained in 14 CAE patients and 13 age-and gender-matched healthy controls.The data were analyzed using voxel-based analysis (VBA) and statistically compared between patients and controls.For the regions with significant difference in group comparison, their DTI metrics were further analyzed with clinical symptoms using Pearson's correlation.ResultsPatients showed significant increase of apparent diffusion coefficient (ADC) in left medial prefrontal cortex (MPFC) (P=0.042), while fractional anisotropy (FA) value was significantly decreased in left precuneus (P=0.010).In correlation analysis, ADC value from left MPFC was positively associated with duration of epilepsy.Neither the disease duration nor the seizure frequency showed significant correlation with FA values.ConclusionThe findings indicate that structural impairments exist in DMN regions in children suffering from absence epilepsy.This may contribute to understanding the pathological mechanisms and chronic neurological deficits of this disorder.

    Release date:2017-05-24 05:46 Export PDF Favorites Scan
  • SYNTHETICAL TREATMENT FOR FACIAL PARALYSIS USING STATIC AND DYNAMIC TECHNIQUES

    Objective To investigate a synthetical technique combining static and dynamic states for treating facial paralysis. Methods From October 1993 to November 2005, 93 patients (26 males, 67 females; aged 9-69 years; illness course, 6 months to 24 years) with facial paralysis were admitted for treatment, of whom 48 were unknown in their pathological origins, 32 had a history of intracranial or ear operation, 13 had their facial paralysis related to trauma. We applied synthetical techniques for treating facial paralysis, including denerved muscle (extensor hallucis brevis and extensor digitorum brevis) free graft using an operating or chemical technique, temporal muscular flap suspending, treatment of eye closure by uplifting zygomomalar tissues and temporal muscular flap suspending, brow lifting by the Buried Guiding Suture Appliance, Botox injection, and the nerve amputation of normal side for mandibular marginal ramus paralysis. Results After the treatment for 82 patients with the method of the denerved muscle free graft combining femporal muscular flap suspending, 3 patients with the method of uplifting zygomo-malar tissues combining temporalmuscular flap suspending for eye closure, 15 patients with the method of the Buried Giding Suture for eyebrow lifting, 4 patients with the Botox injection and nerve amputation of normal side for the mandibular marginal ramus paralysis,93 patientshad a good therapeutic result. The follow-up for 3 months to 10 years in all the patients revealed that 75 patients were satisfied with their treatment results and 13 patients were almost satisfied according to the criteria for the facialsymmetrical checking and the House-Brackmann grading system. The technique hadadvantages of a complete survival of the related small muscles, a hidden incision, less trauma for the Botox injection, and the denerved muscles for surrounding nerve inserting. Conclusion The synthetical technique combining static and dynamic states for treating facial paralysis is a good therapeutic method and the therapies for facial paralysis should vary with the different conditions of the paralysis. We advocate an individuation treatment for facial paralysis.

    Release date:2016-09-01 09:25 Export PDF Favorites Scan
  • Research on brain white matter network in cerebral palsy infant

    Present study used diffusion tensor image and tractography to construct brain white matter networks of 15 cerebral palsy infants and 30 healthy infants that matched for age and gender. After white matter network analysis, we found that both cerebral palsy and healthy infants had a small-world topology in white matter network, but cerebral palsy infants exhibited abnormal topological organization: increased shortest path length but decreased normalize clustering coefficient, global efficiency and local efficiency. Furthermore, we also found that white matter network hub regions were located in the left cuneus, precuneus, and left posterior cingulate gyrus. However, some abnormal nodes existed in the frontal, temporal, occipital and parietal lobes of cerebral palsy infants. These results indicated that the white matter networks for cerebral palsy infants were disrupted, which was consistent with previous studies about the abnormal brain white matter areas. This work could help us further study the pathogenesis of cerebral palsy infants.

    Release date:2017-10-23 02:15 Export PDF Favorites Scan
  • EFFECTIVENESS ANALYSIS OF OLD EXTENSOR TENDON INJURY IN ZONE II

    ObjectiveTo discuss the effectiveness of operative treatments for different kinds of old injury of extensor tendon in zone II so as to choose the best surgical approach based on the classification of injury. MethodsBetween May 2006 and May 2014, 68 cases of old injury of extensor tendon in zone II were treated. Among them, there were 50 males and 18 females with an average age of 36 years (range, 18-52 years). The causes included contusion injury in 50 cases, avulsion injury in 11 cases, and burn injury in 7 cases. The left side was involved in 21 cases and the right side in 47 cases. The injured finger involved the index finger in 18 cases, the middle finger in 21 cases, the ring finger in 24 cases, and the little finger in 5 cases. The disease duration was 1.5 months to 1 year (mean, 6.75 months). The central slip of extensor was repaired directly in 32 patients who had normal passive motion. Side cross stitch (8 cases) or Littler-Eaton (10 cases) method was used in 18 patients who can not extend actively and passively. Tendon graft was performed in 11 patients with tendon defect. Joint release was given in 7 patients with contracture after burn injury. ResultsPrimary healing of incision was obtained in all cases. Sixty-eight cases were followed up 3-12 months (mean, 6.9 months). Three cases had tendon adhesion in varying degrees and suffered from pain, which was treated conservatively by functional exercise. Recurrence was observed in 2 cases, and extensor tendon was repaired again. According to total active motion (TAM) function assessment, the results were excellent in 52 cases, good in 11 cases, fair in 3 cases, and poor in 2 cases with an excellent and good rate of 92.6%. ConclusionAdaptive operation method for old injury of extensor tendon in zone II should be selected based on the type of injury. The results will be satisfactory if correct method is chosen.

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  • CLINICAL SIGNIFICANCE OF ELECTROPHYSIOLOGICAL DOMINANCE ANALYSIS OF TRICEPS BRACHIIMUSCLE/EXTENSOR DIGITORUM COMMUNIS MUSCLE INNERVATION IN IPSILATERAL C7 TRANSFER

    Objective To analysis the electrophysiological dominance weight of the triceps brachii muscle/extensordigitorum communis muscle innervated by brachial plexus and to conclude its effect on the ipsilateral C7 transfer so as to offer electrophysiological data for the safety and indication of i psilateral C7 transfer. Methods From August 2007 to October 2007, 15 patients with complete brachial plexus nerve root avulsion received contralateral C7 transfer. There were 13 males and 2 females aged 18-49 years (28 years on average). Injury was caused by fall ing in 1 case, by crush in 2 cases and by traffic accident in 12 cases, involving left side in 8 cases and right side in 7 cases. The upper, middle and lower trunk of the brachial plexus were stimulated respectively, the compound muscle action potential (CMAP) at the triceps brachii muscle/extensor digitorum communis muscle was recorded, and then the electrophysiological dominance weight of the triceps brachii muscle/extensor digitorum communis muscle innervated by brachial plexus was confirmed according to the comparison of the ampl itude percentage of the CMAP by three trunks. The muscle strength of triceps brachii muscle/extensor digitorum communis muscle was evaluated and the electromyogram was taken 6 months after operation. Results All patients were followed up for 6 months. Concerning the electrophysiological dominance weight, the triceps brachii muscle was mainly innervated by uppermiddle trunk in 3 cases (20%), by middle-lower trunk in 3 cases (20%), by whole trunk in 7 cases (47%) and by middle trunk in 2 cases (13%). While the extensor digitorum communis muscle was mainly innervated by middle-lower trunk in 3 cases (20%), by whole trunk in 10 cases (67%) and by lower trunk in 2 cases (13%). Concerning the triceps brachii muscle, 2 patients got the muscle strength of 4 grade with recruitment simple phase at 1 month after operation and returned to normal at 3 month after operation, while 13 patients got the muscle strength of 5 grade with recruitment simple or mixed phase at 1 month after operation. Concerning the extensor digitorum communis muscle, the muscle strength and the recruitment phase of all 15 patients recovered to normal at 1 month after operation. Conclusion To patients with various kinds of electrophysiological dominance weight, the cutting of C7 does not substantially damage the triceps brachii muscle or extensor digitorum communis muscle, indicating that the ipsilateral C7 transfer is safe and feasible. However, it should be appl ied prudently for the patients with high dominance weight since it may result in the short-term decrease of triceps brachii muscle strength.

    Release date:2016-09-01 09:17 Export PDF Favorites Scan
  • Research on Non-rigid Registration of Multi-modal Medical Image Based on Demons Algorithm

    Non-rigid medical image registration is a popular subject in the research areas of the medical image and has an important clinical value. In this paper we put forward an improved algorithm of Demons, together with the conservation of gray model and local structure tensor conservation model, to construct a new energy function processing multi-modal registration problem. We then applied the L-BFGS algorithm to optimize the energy function and solve complex three-dimensional data optimization problem. And finally we used the multi-scale hierarchical refinement ideas to solve large deformation registration. The experimental results showed that the proposed algorithm for large deformation and multi-modal three-dimensional medical image registration had good effects.

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