Sectional neuroanatomy of the lower thoracic spine and chest

This is the fourth in a series of articles on the spine. The first reviewed the anatomy of the neck; the second reviewed the upper thoracic spine and chest (T1-T4); and the third reviewed the middle thoracic spine and chest (T5-T8). The procedures performed in the lower thoracic spine include percutaneous biopsies of the liver and kidneys, percutaneous nephrolithotomy, spinal injections, radiofrequency ablations, electromyography of the diaphragm, trigger point injections, chemodenervation with botulinum toxin, acupuncture, aneurysm repair, and, occasionally, chest tube placement in the lower lung fields. Complications include subcapsular hematomas, infections, pneumothorax, hemothorax, spinal cord ischemia and resultant paraplegia, and, rarely, nephropleural fistulas. This article provides anatomically accurate schematics of innervations of the lower thoracic chest and spine (T9-T12) that can be used to interpret the magnetic resonance images of the muscles and the nerves. Cross-sectional schematics of the lower thoracic chest and spine were drawn as they appear on imaging projections. The relevant nerves were color coded. The muscles and skin surfaces were labeled and assigned the color of the appropriate nerves. An organized comprehensive map of the motor innervation of the lower thoracic chest and spine allows the physician to increase the accuracy and the efficacy of interventional procedures. This could also assist the electromyographer in correlating the clinical and electrophysiological findings with magnetic resonance images.     

Sectional neuroanatomy of the middle thoracic spine (t5-t8) and chest

This is the third in a series of articles on the spine. The first reviewed the anatomy of the neck. The second reviewed the upper thoracic spine and chest (T1-T4). A fourth article is planned for the lower thoracic spine. Procedures in the midthoracic spine include chest tube placement, trigger point injections, chemodenervation with botulinum toxin, video-assisted thoroscopic surgery, and spinal injections. Complications include pneumothorax, hemothorax, diaphragmatic irritation, sympathetic trunk irritation, postthoracotomy pain, and intradural abscesses. This article provides anatomically accurate schematics of innervations of the middle thoracic chest and spine (T5-T8) that can be used to interpret magnetic resonance images of the muscles and nerves. Cross-sectional schematics of the middle thoracic chest and spine were drawn as they appear on imaging projections. The relevant nerves were color coded. The muscles and skin surfaces were labeled and assigned the color of the appropriate nerves. An organized comprehensive map of the motor innervation of the middle thoracic chest and spine allows the physician to increase the accuracy and efficacy of interventional procedures. This could also assist the electromyographer in correlating the clinical and electrophysiologic findings with magnetic resonance images.     

Sectional neuroanatomy of the face

Needle electromyography and the injection procedures of the face are difficult because of the small size and close anatomic relations of the facial structures. Local injections of the face have increased in frequency since the introduction of botulinum toxin. This article intends to provide anatomically accurate schematics of innervation of the muscles of facial expression that can be used to interpret magnetic resonance images of the muscles and nerves. Cross-sectional schematics of the face were drawn as they appear in imaging projections. The relevant cranial and spinal nerves were color coded. The muscles and skin surfaces were labeled and assigned the color of the appropriate nerves. An organized comprehensive map of the motor innervation of the face allows the physician to increase the accuracy and efficacy of interventional procedures. This could also assist the electromyographer in correlating the clinical and electrophysiologic findings with magnetic resonance images.     

Sectional neuroanatomy of the upper thoracic spine and chest

This is the second in a series of articles on the spine. The first reviewed the anatomy of the neck. Subsequent articles are planned to cover the anatomy of the middle and lower thoracic spine. Procedures and trauma of the upper thoracic spine and chest are fraught with potentially serious complications. Hemothorax, pneumothorax, nerve damage, pulmonary collapse, and thoracic aortic aneurysm are included in the list. This article provides anatomically accurate schematics of innervation of the upper thoracic chest and spine that can be used to interpret magnetic resonance images of the muscles and nerves. Cross-sectional schematics of the upper chest and spine were drawn as they appear in imaging projections. The relevant nerves were color coded. The muscles and skin surfaces were labeled and assigned the color of the appropriate nerves. An organized comprehensive map of the motor innervation of the upper chest and spine allows the physician to increase the accuracy and efficacy of interventional procedures. This could also assist the electromyographer in correlating the clinical and electrophysiologic findings with magnetic resonance images.     

Procedure-oriented sectional anatomy of the elbow

This is the second in a series of papers related to procedure-oriented joint anatomy. This article will review the anatomy of the elbow and its relationship to procedures in the clinical setting. Needle procedures of the elbow joint include medial and lateral epicondyle injections, olecranon bursa injection, elbow joint aspiration, phlebotomies in the antecubital fossa, and intramuscular injections such as trigger point and botulinum toxin injections. Complications related to these procedures include infection, skin atrophy, injuries to peripheral nerves, tendon rupture associated with the use of corticosteroids, iatrogenic vascular injuries, and chronic local pain. This article provides anatomically accurate schematics of the elbow anatomy relevant to needle procedures. Cross-sectional anatomical schematics of the elbow were drawn as they appear on axial and coronal projections. Superficial and deep landmarks are highlighted as well as sources of potential complications. These schematics allow for safer and more accurate needle procedures in the elbow area, for both nonguided and musculoskeletal ultrasound-guided techniques.     

Incremental value of magnetic resonance neurography of Lumbosacral plexus over non-contributory lumbar spine magnetic resonance imaging in radiculopathy: A prospective study

AIM: To test the incremental value of 3T magnetic resonance neurography (MRN) in a series of unilateral radiculopathy patients with non-contributory magnetic resonance imaging (MRI).METHODS: Ten subjects (3 men, 7 women; mean age 54 year and range 22-74 year) with unilateral lumbar radiculopathy and with previous non-contributory lumbar spine MRI underwent lumbosacral (LS) plexus MRN over a period of one year. Lumbar spine MRI performed as part of the MRN LS protocol as well as bilateral L4-S1 nerves, sciatic, femoral and lateral femoral cutaneous nerves were evaluated in each subject for neuropathy findings on both anatomic (nerve signal, course and caliber alterations) and diffusion tensor imaging (DTI) tensor maps (nerve signal and caliber alterations). Minimum fractional anisotropy (FA) and mean apparent diffusion coeffcient (ADC) of L4-S2 nerve roots, sciatic and femoral nerves were recorded.RESULTS: All anatomic studies and 80% of DTI imaging received a good-excellent imaging quality grading. In a blinded evaluation, all 10 examinations demonstrated neural and/or neuromuscular abnormality corresponding to the site of radiculopathy. A number of contributory neuropathy findings including double crush syndrome were observed. On DTI tensor maps, nerve signal and caliber alterations were more conspicuous. Although individual differences were observed among neuropathic appearing nerve (lower FA and increased ADC) as compared to its contralateral counterpart, there were no significant mean differences on statistical comparison of LS plexus nerves, femoral and sciatic nerves (P > 0.05).CONCLUSION: MRN of LS plexus is useful modality for the evaluation of patients with non-contributory MRI of lumbar spine as it can incrementally delineate the etiology and provide direct objective and non-invasive evidence of neuromuscular pathology.     

脊神经丛MR成像的研究进展

脊神经丛各组成支神经细小,周围结构复杂,脊神经丛的MR成像一直是研究的重点和难点。常用于脊神经丛成像的MRI技术包括多种重T₂WI抑脂序列、扩散张量成像(DTI)、扩散峰度成像(DKI)、计量T₂值的T₂-mapping和三维神经鞘信号增高并背景抑制弛豫增强的快速采集定量成像(3D SHINKEI-Quant)、磁化转移率(MTR)成像等。此外,对比剂成像、显微神经成像等技术还有待进一步发展。对上述MRI技术在脊神经丛中的臂丛及腰骶丛中的应用作一综述。     

Magnetic resonance--guided musculoskeletal interventional radiology

As an imaging modality, magnetic resonance (MR) guidance has great potential to direct diagnostic and therapeutic procedures performed in the musculoskeletal region and influence patient management. MR-guided interventional procedures involving bone, soft tissue, intervertebral discs, and joints are safe and sufficiently effective for use in clinical practice. This article discusses and illustrates the procedural characteristics and techniques when performing MR-guided musculoskeletal interventions. Biopsy procedures are similar to other modalities for bone and soft tissue lesions. MR guidance is advantageous if the lesion is not visible by other modalities and for regions adjacent to hardware and implants, subselective targeting, intra-articular locations, and periarticular cyst aspiration. MR guidance has also been used for a host of spine injections and pain management procedures such as sacroiliac joint injections, discography, transforaminal epidural injection, selective nerve block, sympathetic block, celiac plexus block, and facet joint cryotherapy neurotomies. Future directions of clinical applications include tumor ablation and multimodality procedure suites. MR-guided musculoskeletal procedures will continue to be a growth area particularly for the diagnosis and treatment of bone and soft tissue neoplasia.     

Acquired degenerative changes of the intervertebral segments at and suprajacent to the lumbosacral junction. A radioanatomic analysis of the nondiskal structures of the spinal column and perispinal soft tissues

In earlier evolutionary times, mammals were primarily quadrupeds. However, other bipeds have also been represented during the course of the Earth's several billion year history. In many cases, either the bipedal stance yielded a large tail and hypoplastic upper extremities (e.g., Tyrannosaurus rex and the kangaroo), or it culminated in hypoplasia of the tail and further development and specialization of the upper extremities (e.g., nonhuman primates and human beings). In the human species this relatively recently acquired posture resulted in a more or less pronounced lumbosacral kyphosis. In turn, certain compensatory anatomic features have since occurred. These include the normal characteristic posteriorly directed wedge-shape of the L5 vertebral body and the L5-S1 intervertebral disk; the L4 vertebral body and the L4-L5 disk may be similarly visibly affected. These compensatory mechanisms, however, have proved to be functionally inadequate over the long term of the human life span. Upright posture also leads to increased weight bearing in humans that progressively causes excess stresses at and suprajacent to the lumbosacral junction. These combined factors result in accelerated aging and degenerative changes and a predisposition to frank biomechanical failure of the subcomponents of the spinal column in these spinal segments. One other specific problem that occurs at the lumbosacral junction that predisposes toward premature degeneration is the singular relationship that exists between a normally mobile segment of spine (i.e., the lumbar spine) and a normally immobile one (i.e., the sacrum). It is well known that mobile spinal segments adjacent to congenitally or acquired fused segments have a predilection toward accelerated degenerative changes. The only segment of the spine in which this is invariably normally true is at the lumbosacral junction (i.e., the unfused lumbar spine adjoining the fused sacrum). Nevertheless, biomechanical failures of the human spine are not lethal traits; in most cases today, mankind reaches sexual maturity before spinal biomechanical failure precludes sexual reproduction. For this gene-preserving reason, degenerative spinal disorders will likely be a part of modern societies for the foreseeable eternity of the race. The detailed alterations accruing from the interrelated consequences of and phenomena contributing to acquired degenerative changes of the lumbosacral intervertebral segments as detailed in this discussion highlight the extraordinary problems that are associated with degenerative disease in this region of the spine. Further clinicoradiologic research in this area will progressively determine the clinical applications and clinical efficacy of the various traditional and newer methods of therapy in patients presenting with symptomatic acquired collapse of the intervertebral disks at and suprajacent to the lumbosacral junction and the interrelated degenerative alterations of the nondiskal structures of the spine.     

Sonography of occult dysraphism in neonates and infants with MR imaging correlation.

High-resolution spinal sonography has become an accepted study to screen for occult dysraphic lesions (ODLs) in neonates and infants. These defects are thought to be caused by abnormal fusion or closure of embryonic dorsal midline structures. Sonographic findings suggestive of an ODL include low position of the conus, nontapered bulbous appearance of the conus, dorsal location of the cord within the bony canal, solid or cystic masses in the distal canal or soft tissue of the back extending toward the canal, patulous distal thecal sac, and thick filum. Physical findings suggestive of ODLs include lumbosacral skin dimples, lumbosacral masses, lower extremity weakness, and an extra appendage arising from the back. The appearances of a normal infant spine, dorsal dermal sinus, lipoma, lipomyelomeningocele, lipomyelocele, myelocystocele, and diastematomyelia are depicted sonographically and correlate with those on magnetic resonance (MR) images. MR imaging is most useful when sonographic findings are abnormal or equivocal or when normal skeletal maturation limits sonographic visualization of the intracanalicular contents.     

Late diagnosis of dorsolumbar lipomyelomeningocele with tethered cord in a middle aged adult: A case report from Nepal

Closed spinal dysraphism can present with diagnostic issues in settings with limited resources, when knowledge of the disorder and specialized radiological studies, such as magnetic resonance imaging (MRI), may not be readily available. Undiagnosed cases can develop serious neurological deficits. Here, we describe a case of dorsolumbar lipomyelomeningocele, a type of closed spinal dysraphism, presenting in a middle aged with paraplegia complicated by bed sores. A 38-year-old female with no significant past medical history experienced gradually progressive weakness of bilateral lower limbs over 9 years. On physical examination, patient had a soft swelling with hairy tuft over the lumbar spine, paraplegia, grade III bed sore over the gluteal region, and sensory loss below L1 sensory level. Her bowel and bladder sensation were decreased. The soft tissue swelling over her back was not evaluated appropriately before this presentation. MRI of the spine revealed dorsolumbar lipomyelomeningocele with tethered spinal cord.     

Degenerative endplate changes of the lumbosacral spine: dynamic contrast-enhanced MRI profiles related to age, sex, and spinal level

Purpose

To investigate differences in perfusion profiles between degenerative endplate marrow changes and normal vertebral marrow in relation to spinal level, age, and sex with dynamic contrast‐enhanced magnetic resonance imaging (DCE MRI).

Materials and Methods

Ninety‐two consecutive patients referred for evaluation of low back pain or sciatica, without history of malignant or chronic disease, underwent conventional and DCE MRI of the lumbosacral spine. Fifty‐two of them demonstrated degenerative endplate marrow changes. Regions of interest were placed on sites of normal marrow (group A) and degenerative changes (group B) on subtracted images. Fitted time‐intensity curves (fTICs) were generated and evaluated for curve pattern. Both groups were stratified into upper (L1‐L2) and lower (L3‐I1) levels, males and females younger or older than 50 years. Perfusion parameters were calculated and statistically compared for both groups and subgroups. Receiver operator curve (ROC) analysis was also performed.

Results

Two fTIC patterns were identified. Perfusion parameters of degenerative changes and normal marrow differed significantly, even when groups were stratified for spinal level, age, and sex (P < 0.05). A time to peak value >108 seconds was characteristic for degenerative changes with sensitivity 69.5% and specificity 84.6%.

Conclusion

DCE MRI profiles of degenerative endplate marrow changes of the lumbosacral spine differ significantly from normal marrow regardless of spinal level, age, or sex. J. Magn. Reson. Imaging 2011;33:382–389. © 2011 Wiley‐Liss, Inc.     

Assessment of the spine with CT and MRI prior to interspinous/interlaminar spinal procedures: a pictorial review

Imaging of the spine is increasingly available, whether as dedicated spine examinations or as studies that include the spine in the images obtained (e.g. CT abdomen). This pictorial review discusses imaging of the spine with CT and MRI and how prior review of this imaging can be helpful with potentially difficult spinal procedures. Pathologies illustrated include osteoarthritis, scoliosis, inflammatory spondyloarthropathies and post-operative spines.Many spinal procedures are performed using the interspinous (midline) or interlaminar (paramedian) approach with high success rates. These procedures include myelograms for diagnosis, epidural corticosteroid injections for pain relief, central neuraxial blocks in regional anaesthesia and lumbar punctures for cerebrospinal fluid (CSF) analysis. The causes for difficult spinal procedures are wide in range and include pathological/anatomical conditions of the spine. As with all imaging as a whole, spinal imaging is increasingly more available with each individual patient [1], and review of such imaging can be helpful for difficult procedures.This pictorial review will discuss imaging (CT, MRI) of spinal conditions that can contribute to difficult spinal procedures, in particular osteoarthritis, scoliosis and the inflammatory spondyloarthropathies. The illustrations will focus on the interspinous/interlaminar approach for the thoracolumbar spine, but the principles provided can be used for other approaches.     

Bildgebung extraduraler Raumforderungen

There is a wide variety of spinal extradural tumors. In addition to real neoplasms, degenerative diseases, congenital abnormalities and inflammatory disorders can be causes of extradural masses. Due to the bony boundary of the spinal canal, both benign as well as malignant masses can cause progressive neurological deficits including paraplegia. Most of the spinal tumors are benign (hemangioma of the vertebral body, degenerative diseases). In younger patients congenital abnormalities and primary tumors of the spine have to be considered, whereas in adults the list of differential diagnoses should include secondary malignancies such as metastases and lymphomas as well as metabolic disorders such as osteoporotic vertebral compression fracture and Paget's disease. Cross-sectional imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) of the spine often help to make a specific diagnosis of extradural spinal lesions and represent important tools for tumor staging and preoperative evaluation.     

乳房假体植入后破裂及泄漏的MRI表现

目的：探讨磁共振诊断乳房假体破裂和（或）泄漏的临床价值。方法：对17例隆乳术后患者行MR扫描，对1个体外正常硅胶液硅胶囊袋假体行相同序列MR扫描作为正常参照。对囊袋假体及注射聚丙烯酰胺假体的MR表现进行分类分析。结果：正常硅胶囊袋单腔假体7例12个，其中4例8个囊内为硅胶液；3例4个囊内为生理盐水。生理盐水硅胶囊袋单腔假体破裂2例2个，其中1 个属囊内破裂，MRI示残留塌陷的硅胶囊袋呈长条状长T1、短T2信号；另1个属囊外破裂，MRI示假体内有多条丝状短T2低信号，即“条丝征”，同侧乳房外见假体内容物颗粒。注射聚丙烯酰胺假体10例20个，其中1例2个完整；8例16个完全破裂，表现为多发条块状、结节状长T1、长T2信号，8例中有7例见双侧乳房腺体内及乳房外有注射物颗粒；1例2个内部撕裂，MRI表现为假体内有多发“条丝征”。结论：MR检查可明确乳房假体的类型、位置；明确假体破裂类型及漏出物的分布范围；因此能为临床手术提供准确定位，为随访复查提供客观资料。     

乳房假体植入后破裂及漏出的MRI表现

目的 探讨MRI诊断乳房假体破裂和(或)泄漏的临床价值. 资料与方法 对15例隆乳术后患者行MR扫描,对囊袋假体及注射聚丙烯酰胺假体的MR表现进行分类分析,与正常假体对照. 结果 硅胶囊袋单腔假体13例26个,囊内为硅胶液;1例2个为双囊假体,外囊为生理盐水,内囊为硅胶液.其中正常假体5例,均为单囊硅胶囊袋假体.硅胶囊袋单腔假体破裂8例16个,其中1例属囊内破裂,MRI示残留塌陷的硅胶囊袋呈长条状长T1、短T2信号;其余为囊内、外均破裂,MRI示假体内有多发条、丝状长T1短T2信号,即"条丝征"、"舌样征",同侧乳房外见假体内容物颗粒.注射聚丙烯酰胺假体1例2个,完全破裂,表现为多发条块状、结节状长T1、长T2信号,MRI表现为假体内有多发"条丝征". 结论 MR检查可明确乳房假体的类型、位置;明确假体破裂的类型及漏出物的分布范围;因此能为临床手术提供准确定位,为随访复查提供客观资料.     

Multifocal Pott's disease (tuberculous spondylitis) incidentally detected on Tc-99m MDP bone and Ga-67 citrate scintigraphy in a patient with diabetes

Pott's disease is an uncommon extrapulmonary form of tuberculosis. Delay in diagnosis and management may cause serious complications. The authors describe Pott's disease incidentally detected on Tc-99m MDP bone and Ga-67 imaging in a patient with diabetes. Tc-99m MDP bone scintigraphy showed intensely increased uptake in the lower cervical spine and lumbosacral regions. Ga-67 scintigraphy revealed intensely increased uptake corresponding to the areas noted on Tc-99m MDP bone scintigraphy. Magnetic resonance imaging showed destructive lesions in the C5-C6 and L5-S1 intervertebral discs with destruction of adjacent end plates. Biopsy of the lumbosacral area was guided by computed tomography, and histologic examination of the bone specimen showed caseation, giant cells, and acid-fast bacilli. Posterior decompression and posterolateral spinal fusion with bone grafts were performed. Antituberculous chemotherapy with isoniazid, rifampicin, pyrazinamide, and ethambutol was started. The patient showed remarkable relief of symptoms during a period of 9 months of therapy. Both Tc-99m MDP bone and Ga-67 imaging can offer the convenience of screening the entire body to detect multiple sites of Pott's disease.     

The assessment of intersegmental motion and pelvic tilt in elite oarsmen

Low back pain (LBP) is a common problem in elite oarsmen. The relevance of spinal and pelvic flexibility to good rowing technique and the incidence of LBP is unclear. PURPOSE: The aim of this study was to investigate patterns of spinal and pelvic mobility in a group of elite oarsmen with and without a history of LBP. METHODS: Twenty elite oarsmen were recruited into this study, including nine with no history of spinal problems, four with a current spinal problem, and the remainder with a history of LBP. Subjects were scanned using an interventional magnetic resonance imaging (MRI) scanner. Four key stages of the rowing stroke were simulated within the scanner, and sagittal images of the lumbar spine and sacrum were obtained. From these images intersegmental motion was determined along with the angle of lordosis and position of the lumbar spine and sacrum. RESULTS: Different mobility trends were seen; oarsmen with no history of LBP demonstrated the greatest mobility in their lower lumbar regions (at the L5/S1 level in the catch position 7.5 degrees +/-1.3 in normals; 4.8 degrees +/-1.2 in previous LBP groups; and 2.8 degrees +/-5.5 in current LBP group) and the lowest rotation of their pelvis (level in the catch position 13.9 degrees +/-11.2 in normals; 16.1 degrees +/-6.8 in previous back pain groups; and 15.2 degrees +/-11.2 in current back pain group). In contrast, those with either current or previous LBP presented with a hypomobility of their spine which appeared to be compensated for by increased pelvic rotation. CONCLUSIONS: Marked differences were observed in the motion characteristics of these 3 groups of oarsmen. At present it is not known if these changes are causative or effect.     

Oblique plane MR imaging of the cervical spine

Surface coil magnetic resonance (MR) imaging of the spine in conventional sagittal and parasagittal planes has been reported to show the cervical tissues with great clarity. Theoretically, an imaging plane perpendicular to the cervical neural foramina would be particularly effective for demonstrating the cervical spinal nerves and roots. We correlated MR images and cryomicrotome sections of the cervical spine to analyze the MR appearance of the neural foramina in this view. The normal MR appearances of the dorsal and ventral roots in cross section and, for the first time, the interradicular cleft were identified. New criteria for diagnosis of nerve root compression were suggested by the anatomic observations.     

The value of fat saturation sequences and contrast medium administration in MRI of degenerative disease of the posterior/perispinal elements of the lumbosacral spine

Degenerative-inflammatory lumbar spinal pathology is one of the most common reasons why individuals seek medical care, and low back pain is the main symptom among those most commonly associated with this pathologic condition. Pain is commonly attributed to degenerative disc disease, particularly herniated discs, but many different spinal and perispinal structures may undergo degenerative-inflammatory phenomena and produce pain: discs, bone, facet joints, ligaments and muscles. In particular, in patients with non-radicular low back pain, this syndrome may arise from changes of the posterior elements/perispinal tissues of the lumbar spine (i.e., the “posterior vertebral compartment”). They include: facet joint pathology (e.g., osteoarthritis, joint effusion, synovitis and synovial cysts), spondylolysis, spinal/perispinal ligamentous degenerative-inflammatory changes and perispinal muscular changes. It is well known that magnetic resonance is the most sensitive imaging method for the evaluation of spinal degenerative pathology, even in the initial stages of the disease. T2-weighted sequences with fat saturation, and when indicated the use of contrast-enhanced T1-weighted images with fat saturation, permit the visualization of degenerative-inflammatory changes of the posterior elements of the lumbar spine that in most cases would have been overlooked with conventional non-fat suppressed imaging.