Sonoanatomy Observation And Visualization Research Of Brachial Plexus And The Clinical Significance

BACKGROUND&OBJECTIVEIn the past, the main diagnostic tools for disorders of the upper extremities has been X ray, CT and MRI, which have many limitations. Recently, with continuous improvement of the ultrasonography and high-frequency probe, the demonstration of the brachial plexus by ultrasonography has achieved great progress. In1978. La Grange et first reported using ultrasonography in61cases for indirect location of the brachial plexus in nerve blocking. In1988, Fomage used ultrasonography for examination of the muscle and the peripheral nerve in cadavers, and compared the outcomes with those of anatomical dissections. The ultrasonography has the advantage of the no trauma, exact location, dynamic observation, and easy operation. It is gaining momentum in observation of the anatomical features of the brachial plexus, diagnosis of the trauma and guidance for block of the brachial plexusThe application of the computer technology has change the situation. By combination of the graphics obtained through several imaging modes and subjecting them for specific transfiguration, match at the special coordinates can be achieved. And by obtaining complementary information from image overlapping, the shortcomings of isolated imaging mode can be circumvented. Image fusion not only make the clinical diagnosis and treatment more accurate, it also plays an important role in the stereotactic-guided surgical navigation.The study has employed the high-frequency ultrasonography with virtual navigation using various imaging modes, aiming to address the4issues as follows①To sonographic anatomical characteristics and clinical application value of the brachial plexus.②To evaluate the safety and outcomes of interscalene brachial plexus block by ultrasound-guided, nerve stimulation techniques and guided by anatomical landmarks, in order to provide some references for clinical application of ultrasound-guided interscalene brachial plexus block.③The goal of this study was analysed28cases with brachial plexus injury by MRI and ultrasonography which were confirmed by surgical, and discussed the potential of ultrasound in recognizing lesions in the region and defining their sonographic morphology, site, extent, and relations to adjacent anatomic structures,④The goal of this study was analysed28cases with brachial plexus injury by MRI and ultrasonography which were confirmed by surgical, and discussed the potential of ultrasound in recognizing lesions in the region and defining their sonographic morphology, site, extent, and relations to adjacent anatomic structures.[METHODS]1. sonographic examination to the brachial plexus:high-resolution ultrasonography was carried out in110volunteers to examined the brachial plexus for that visualize the ultrasonographic characteristics and anatomical modification, and confirmed distribution features and the relationship with the surrounding tissue anatomic localization,with scanning in intervertebral foraminal, interscalene, supraclavicular, subclavian and armpit. We compared analysed bony structure of the intervertebral foraminal in the form and the imaging and observed where is brachial plexus root imaged between the20volunteers who had undergone CT and ultrasonography. 2. Brachial plexus block:one hundred and fifty patients of ASA Ⅰ or Ⅱ scheduled for upper extremity operation were randomly divided into three groups:Group A(ultrasoun-guided), Group B(nerve stimulation techniques), Group C(aguided by anatomical landmarks). A mixture of local anaesthetic(0.375%ropivacaine and1.0%lidocaine)was injected in each group. Each group was blocked under corresponding diverse ways.The operation time of block, the duration of analgesia and the complications were recorded, the time of pain deprivation of axillary nerve, cutaneous nerve,ulnar nerve, median nerve and radial nerve were measured, and the extent of pain sensory block(completeness、part、lack), the effects of anesthesia(excellent、good、failure)during operation were assessed.3. Ultrasound and MRI for depiction of brachial plexus injury:the28cases with brachial plexus lesions which were confirmed with by surgical had examined bilaterally contrast ultrasound at the level of the vertebral foramina and then were followed longitudinally and axially down to the axillary region, we recorded the ultrasonographic characteristics and anatomical modification, and confirmed distribution features and the relationship with the adjacent tissue anatomic localization.and then compared with MRI and the surgical findings.4. Multimodality medical imaging fusion and virtual navigation:eight patients with thoracic outlet syndrome and10cases scheduled for upper extremity operation involvement were studied. After performing1.5T MRI (T1, T2and short time inversion recovery sequences) of brachial plexus, images were recorded in a US machine equipped with a virtual navigator system. Ultrasonography was performed in the same position. Image MRI/US superposition was carried out, with real-time contemporary visualization of the US and related MRI images. The percentage of successful image fusion and the time for image fusion, as well as the result of virtual navigation assisted brachial plexus procedures. [RESULTS]1. Compared with the20volunteers who had undergone CT, High-resolution ultrasonography can clearly performed parapophysis so that we can observed the brachial plexus root. The normal brachial plexus root out of intervertebral foraminal showed a symmetrical hypoecho structure. The C5-C7nerve root detection rate was100%. and the C8and T1detection rate was83%and68%. The C7nerve root vertebral body is the sign of identifying nerve root.The normal brachial plexus were displayed on the cross-sectional views as round or elliptical structures with hyperechogenic and a multiple linear parallel low-medium echo with small focal Weak echo on the longitudinal views.The parapophysis, scalene fissure, subclavian artery and arteria cervicalis profunda of C7is an important sign of the check. The C5-C7detection rate was100%(12/12case), and the Cg and T1detection rate was83%(10/12case).The brachial plexus of interscalene, supraclavicular and armpit detection rate all for100%and the brachial plexus of subclavian detection rate was97%.2. Interscalene brachial plexus were identified as oval hypoe-ehoie structure in transverse view and defined internally small echogenic dots.The nerves were infiltrated after local anesthesia. Time required to perform the block was shorter in Group A as compared with Group B and C. The effects of pain sensory block of radial nerve, ulnar nerve and axillary nerve in Group B and C were more complete than that in Group A (P<0.05), there was no significant difference between B and C Group in the effects of pain sensory block of axillary nerve, musclecutaneous nerve, medial nerve and radial nerve(P>0.05). The effects of pain sensory block of radial nerve, ulnar nerve and axillary nerve in Group B and C were more complete than that in Group A (P<0.05), The excellent anesthesia rate in Group A and Group B was higher than that in Group C(P<0.05). The duration of analgesia in Group A and B was longer than that in Group C (P<0.05). No complication occurred in Group A. Four adverse events occurred in Group C(4cases of vascular puncture.2case of mild toxic reaction).3. Abnormal ultrasound findings were detected in24of28patients and the detection rate was85.7%(24/28). Disruption of nerve continuity and the normal structure disappeared was found in5case,and three of them are nerve root avulsioned and one of them accompanied vertebral the cyst.2case are partial disruptions with distal nerve as sample swelling spindle.17case partial brachial plexus are swelling and thickening with with the surrounding soft tissue echo obscureed, disordered, adhered,and formed as scar tissue. Brachial plexus lesions included preganglionic neuron and postganglionic neuron injured in MRI.Two of28case are preganglionic neuron injured in MRI,and26of them are postganglionic neuron injured,and the detection rate was100%(28/28). Preganglionic neuron injured in the canalis vertebralis performaned that2case are nerve root of the dural sac and foramen intervertebrale disappeared,1case are spinal cord edema and haemorrhage,1case are spinal cord translocation, and2case are sacral meningeal cyst trauma. Postganglionic neuron injured out of canalis vertebralis with MRI performaned that2case are disruption of nerve continuity and the structure disappeared,2case are neural stem thinner and the structure disordered but partial brachial plexus are swelling and thickening,18case are nerve continuity existed but the diameter are disaffinity thickening,T2WI sign heightened and T1WI sign reduced,and4case are nerve continuity existed but poor displayed, distribution stiffed and the structure disordered. Surgical result:2case are nerve root avulsion,2case are partial disruptions,1case are following with false paravertebral anesthesia cyst,1case can’t be found the stump nerve,12case are nerve edema, thickening and fibrosis,12case are stiff and formed as scar tissue in the nerve trunk,and adhered with the surrounding tissue, and2case are formed as false neurofibroma. 4. Image fusion of MRI by ultrasound was obtained successfully in all cases. The number of identifiable lesions by US increased by using the fusion-guided US, and the method was helpful as guidance for brachial plexus procedures as it enabled us to focus on a specific area.[CONCLUSION]1. High-resolution ultrasonography can provide a new observation methods for the morphological of the brachial plexus, and ultrasonography can clearly showed morphology and relateed with the surrounding tissue, in addition, high-resolution ultrasonography can identified the brachial plexus root through transverse processes of the vertebrae.and the C7nerve root vertebral body is the sign of identifying nerve root, which is provided the radiographic support for diagnosis brachial plexus disease, therefore improve the accuracy of the neural positioning.2. Advanced ultrasound technology can clearly generate brachial plexus and surrounding tissue images in interscalene groove, guide block needle placement real-time to targeted nerves, and make it easy to observe the diffuse pattern of the injected local anaesthetics. These advantages of real-time ultrasonic monitoring provide imaging suppor for the precise positioning of brachial plexus block.3. High-resolution Ultrasound provided valuable information regarding the lesion site, extent, and anatomic relationships particularly to blood vessels; and sonography should be recommended as part of the evaluation process brachial plexus pathology.4. Virtual navigator assisted increased diagnostic confidence of the lesions using different imaging modalities, more precise monitoring of interventional procedures, which may make the technique a promising method for further clincal application.