Benign versus malignant osseous lesions in the lumbar vertebrae: differentiation by means of bone SPET

Bone scanning is a well-accepted and frequently performed diagnostic procedure with a high sensitivity, especially when single-photon emission tomography (SPET) acquisitions are added. However, the differentiation of benign from malignant osseous lesions often poses difficulty. The purpose of this study was to find out whether the particular localisation of an intraosseous lesion in a lumbar vertebra is an indicator of its aetiology. Bone scintigraphy including planar whole-body scans as well as SPET imaging of the lumbar spine was performed in 109 patients. The diagnoses of osseous lesions in the lumbar vertebrae were made strictly on the basis of the findings of magnetic resonance imaging, computed tomography or plain radiography. Sixteen patients had to be excluded from the study because they did not undergo adequate radiological examination. To determine the particular localisation of vertebral lesions in the bone scan, two experienced nuclear medicine physicians examined the studies independently while blinded to the radiological results. Four anatomical regions were differentiated within the vertebra: the vertebral body, the pedicle, the facet joints and the spinous process. Clopper-Pearson analysis, which takes into account the number of examinations, yielded the following probability intervals for the malignancy of intraosseous lesions in the lumbar spine: vertebral body 36.8%–57.3%, pedicle 87.7%– 100%, facet joints 0.8%–21.4% and spinous process 18.7%–81.3%. It was concluded that lesions affecting the pedicle are a strong indicator for malignancy, whereas involvement of the facet joints is usually related to benign disease. Lesions affecting the vertebral body or the spinous process do not show a clear tendency towards either malignancy or benignity. In contrast to other studies, a significant probability of malignancy (35.6%) was observed in lesions affecting exclusively the vertebral body. Received 23 November 1999 and in revised form 12 February 2000     

Pathophysiology, neurology and diagnostic radiology of degenerative diseases of the lumbar spine

Degenerative diseases of the lumbar spine have a high medical and socioeconomic impact. The leading symptom is back pain, but there are many reasons for this. The aim of this paper is to describe the pathogenesis of degenerative diseases of the lumbar spine and their clinical symptoms in relation to the functional anatomy and biomechanics of the spine. Discs, vertebral facet joints, osseous and ligamentous structures as well as the erector trunci muscles are a functional unit. Progressive degenerative changes of the discs induce bone overgrowth and ligamentous thickening, affect the orientation of the vertebral facet joints and change the pressure, tension and shear forces of the spine. The different radiological diagnostic tools are presented and discussed according to the different degenerative diseases of the lumbar spine.     

Vertebral pneumatocysts

Objective: To review the prevalence and location of vertebral pneumatocysts and evaluate the CT findings of these benign lesions.Material and Methods: Retrospectively we reviewed CT images of 89 patients with suspected disc disease during a 6-month period.Results: Distinctive CT pattern of intraosseous pneumatocysts involving the cervical, thoracic and lumbar spine was found. In 8 patients (9%), 10 vertebral pneumatocysts were detected. Five were located in the vertebral body and 4 of these were associated with vacuum phenomenon in adjacent intervertebral discs. Five were located near the facet joint and all were associated with vacuum phenomenon in adjacent facet joint.Conclusion: Intraosseous pneumatocyst is a benign lesion, therefore biopsy and follow-up are unnecessary. Although vertebral pneumatocysts seem to be uncommon with a few reported cases, this study shows them to be more frequent than previously thought.     

腰腿痛中西医结合治疗前后的影像学评价

目的 :对中西医结合疗效显著的腰腿痛病人进行治疗前后影像学评价。方法 :分析 6 2例经中西医结合疗效显著的腰腿痛病人治疗前后的腰椎正侧位片及椎间盘CT片 ,评估治疗前后的影像学变化。结果 :治疗前 ,6 2例CT检查中单纯腰椎间盘膨出 2 8例 ,单纯腰椎间盘突出 12例 ,10例同时有腰椎间盘突出及膨出 ,12例CT扫描无异常 ,但平片 5 3例腰椎均有不同程度侧弯畸形 ,同时有不同程度的旋转伴椎小关节结构紊乱 13例。治疗后复查平片 ,4 5例腰椎侧弯、旋转畸形以及 11例伴有椎小关节紊乱的病例 (占 85 % )均有明显改善 ,CT检查仅 8例椎间盘膨出及突出得到不同程度的回纳 (占 16 % ) ,4 2例椎间盘膨出及突出的程度无明显改善 ,骨性椎管形态及椎体终板疝黄韧带肥厚、腰椎骨质增生等无明显差异。结论 :中西医结合治疗可有效地改善腰腿痛病人的临床症状 ,治疗后腰椎的影像学形态可得到一定程度的改善。     

Comparison of bone single-photon emission tomography and planar imaging in the detection of vertebral metastases in patients with back pain

Bone scan has long been considered to be an important diagnostic test in searching for bone metastases. However, considerable difficulty is encountered in the vertebral region due to the complexity of structures and the fact that other benign lesions, especially degenerative changes, are very common there. Single-photon emission tomography (SPET) has been reported to be useful in the differentiation of benign from malignant conditions. Here we report our experience with bone SPET in the diagnosis of vertebral metastases. This is a retrospective study of technetium-99m methylene diphosphonate (MDP) bone scans in 174 consecutive patients who were referred for the investigation of back pain in our department. MDP planar and SPET images were obtained. Of teh 174 patients, 98 had a known history of malignant tumours. The diagnosis of vertebral metastasis was made on the basis of the patients’ clinical histories and the findings with other imaging techniques such as magnetic resonance imaging, computed tomography or follow-up bone scan. We found that the presence of pedicle involvement as seen on SPET was an accurate diagnostic criterion of vertebral metastasis. SPET had a sensitivity of 87%, a specificity of 91%, a positive predictive value of 82%, a negative predictive value of 94% and an accuracy of 90%. On the other hand, planar study had a sensitivity of 74%, a specificity of 81%, a positive predictive value of 64%, a negative predictive value of 88% and an accuracy of 79% in diagnosing vertebral metastasis. Except with regard to the negative predictive value, SPET performed statistically better than planar imaging. Only 9/147 (6.4%) lesions involving the vertebral body alone and 3/49 (6.1%) lesions involving facet joints alone were subsequently found to be metastases. We conclude that bone SPET is an accurate diagnostic test for the detection of vertebral metastases and is superior to planar imaging in this respect. Received 20 December 1997 and in revised form 16 March 1998     

The benefit of SPECT when added to planar scintigraphy in patients with bone metastases in the spine.

PURPOSE: This study compared the efficiency of SPECT with planar bone scans in differentiating malignant from benign lesions and in detecting metastases to the spine. METHODS: Planar scintigraphy and SPECT were performed in 37 patients with low back pain without known malignancy and in 38 patients with confirmed malignancy. The type, location, and intensity of tracer accumulation were compared on the planar and SPECT scans. The malignant or benign nature of lesions was proved by radiologic methods, histologic findings, 6 month follow-up, or all of these. RESULTS: More metastases were detected by SPECT (SPECT, 58 of 64; planar, 42 of 64; P < 0.01). In three of seven patients with known malignancy who had a normal result of planar scan, only SPECT detected metastases. Fifty-nine metastases were radiologically mainly osteolytic, one was osteoblastic and four were mixed. Most lesions showed increased radioactivity (40 of 42 on planar scans vs. 45 of 58 on SPECT) and 2 of 42 (5%) vs. 12 of 58 (21%) were cold with marginally increased uptake. One of 58 metastases was a cold lesion seen on SPECT only. Lesions were more often malignant than benign when seen on SPECT in a pedicle (n = 5; malignant = 3, benign = 2), in the body and pedicle (n = 22; malignant = 14, benign = 8), within the vertebral body (n = 5; malignant = 4, benign = 1) and in the whole vertebra (n = 6; malignant = 4, benign = 2). The lesion to background ratio was higher on SPECT than on planar scans (SPECT, 2.26; planar scans, 1.86; P < 0.05 in malignant lesions). CONCLUSIONS: SPECT of the spine improved the diagnostic accuracy of bone scans when added to a planar scan in patients with known malignancy and clinical suspicion of spinal metastases when the planar scan was borderline abnormal. It helps in differentiating between benign and malignant lesions of the spine.     

Vertebral venous channels: CT appearance and differential considerations

A comprehensive study of the anatomy, radiologic images, and pathology of venous channels in the thoracic and lumbar vertebral bodies was performed using cadavers and patients. These structures may be mistaken for fractures, lytic lesions, or other abnormalities on high-resolution axial computed tomographic (CT) scans of the spine. A distinct osseous wall, absence of extension over multiple contiguous levels, lack of displacement, and predominant localization in the mid-axial plane of the vertebral body are characteristic features of venous channels. An understanding of the normal intraosseous venous anatomy should prevent misinterpretation of clinical CT studies in most instances.     

腰椎相关结构的退变规律

目的 研究腰椎退变患者腰椎骨质、椎间盘、韧带、椎小关节退变及腰椎退变性失稳与年龄、性别的相关性,探讨腰椎退变规律.资料与方法 对1 180例腰椎退变患者的腰椎CT进行分析,观察不同年龄段、不同性别间椎体骨质、椎间盘、椎小关节、韧带退变以及退变性腰椎失稳的发生率.结果 腰椎退变患者腰椎间盘的退变率最高,其次是腰椎骨质、椎小关节、韧带、腰椎失稳.以36岁为年龄分界,36岁以下为腰椎低退变率年龄,以上是腰椎高退变率年龄,不同结构伴随年龄增长的退变率并不是同步递增的,腰椎骨质、椎小关节、韧带退变率及腰椎失稳发生率最高在65岁以上年龄段,而腰椎间盘退变率最高在36～45岁年龄段.男性腰椎间盘、骨质的退变率明显高于女性;椎小关节、韧带的退变率在男、女性间无显著差异;而女性腰椎失稳率明显高于男性.结论 总体上伴随年龄增长的腰椎退变,其不同结构的退变规律不一,在不同年龄段及性别间都存在明显差异,全面分析腰椎退变的影像表现有利于对腰椎退变性疾病的理解和治疗.     

The direct and computed radiographic assessment of vertebral locations in children with acute lymphatic leukemia]

The children affected with acute lymphoblastic leukemia (ALL) often exhibit secondary lesions of the spine. The diagnosis of spinal involvement is currently made by means of conventional radiography in postero-anterior and lateral views. The osteolytic lesions of the vertebral body present with collapse of the vertebral plates in a wide range of severity. Body evaluation is usually made by comparison with the adjacent vertebrae. Since leukemia is a systemic disease, several vertebrae are possibly involved in each case. In the attempt to develop a more sensitive method, which is less dependent on observers' evaluation, a quantitative and comparative analysis of vertebral bodies was performed. The radiographs in lateral view of the dorsal and lumbar spine of 14 children with ALL were analyzed: previous radiological reports suggested the lesion of one or more vertebral bodies. The area of each vertebral body was measured and digitalized by means of a backlighted graphic table and of a software developed to this purpose. The criteria to define the collapse of a vertebral body were the ratio between areas of adjacent vertebral bodies, in conformity to the anatomic and radiographic principle that, in the dorsal and lumbar spine, the body of a normal vertebra is equal to or bigger than that of the upper one. The data obtained by quantitative analysis were compared with conventional radiologic reports. A hundred and fifty-five vertebrae were analyzed by computerized analysis; 17 (10.9%) vertebrae, undetected at conventional analysis, were collapsed. This method allows a more precise diagnosis of collapsed vertebral lesions; its accuracy can be improved with further development of digital technology.     

Transarticular invasion of joints by bone tumors: hypothesis

Eight bone tumors with associated transarticular invasion of the sacroiliac joints are described. All invaded the true synovial joint and spread to the opposing bone. One tumor was benign, and the other seven were malignant. Five of the seven were primary and two were metastatic cancer. One, a myeloma, invaded the disc spaces between the fourth and fifth lumbar vertebrae and the fifth lumbar vertebra and sacrum as well as the sacroiliac joint. The right facet joints of the two vertebrae were also invaded. After a thorough search of the literature, we find that the sacroiliac joint is the most common joint to be invaded by tumors. This is followed by the vertebral disc spaces and, last, the facet joints. Apart from these joints, we were unable to find any radiographic documentation of other joints being transarticularly invaded by tumors. We noted that there is a direct relation between transarticular tumor spread and joints that lack mobility and that certain tumors, benign and malignant, tend to invade these joints.     

Multisegmental pneumatocysts of the lumbar spine mimic osteolytic lesions

Circumscribed radiolucencies within the vertebral bones can be due to a variety of changes including benign and malignant tumours or tumour-like lesions. Radiolucencies due to degenerative intraosseous pneumatocyst are very uncommon but have to be taken into the differential diagnosis in well-circumscribed lytic lesions of the vertebral bodies. We describe the first case of multisegmental pneumatocysts in the lumbar spine mimicking osteolytic lesions. On computed tomography, the air-equivalent attenuation values of the lesions and the close vicinity to the degenerated vertebral endplates with vacuum phenomenon led to the correct diagnosis. Received: 17 December 1999 Revised: 13 April 2000 Accepted: 18 April 2000     

Percutaneous Vertebroplasty

Percutaneous vertebroplasty (PVP) with acrylic cement [polymethylmethacrylate (PMMA)]consists of injecting PMMA into vertebral bodies weakened by osseous lesions. The aim of PVP with PMMA is to obtain an antalgic effect by consolidation in destructive lesions of the spine. There are three major indications: vertebral angiomas, osteoporotic vertebral crush syndromes, and malignant vertebral tumors. Indications in vertebral angiomas only concern patients with aggressive clinical signs (severe pain or nervous compression) and/or aggressive radiological signs. Indications in osteoporotic vertebral crush syndromes only concern patients suffering from back pain related to one or two adjacent vertebral collapses resistant to medical treatment for several weeks. Indications in malignant vertebral tumors only concern patients suffering from severe back pain related to a destruction of the vertebral body, not involving the major part of the cortical bone. Complications of PVP occur essentially in patients with vertebral metastasis. In the great majority of cases, these complications heal under medical treatment. In patients with osteoporotic vertebral crush syndromes or vertebral angiomas, the complications are represented by the increase or onset of radiculalgias (in less than 1%), which disappear after local anesthetic injection.     

Utility of SPECT imaging for determination of vertebral metastases in patients with known primary tumors

Determining the etiology of a focal lesion seen on bone scan in patients with primary tumors usually requires the use of other imaging procedures or biopsy. Single positron emission computed tomography (SPECT) with high resolution multidetector systems can localize the specific site of a vertebral lesion and in this way potentially differentiate between benign and metastatic disease. SPECT images of the lower thoracic and lumbar spine were reviewed for lesion location and intensity by two experienced interpreters. Follow-up data were adequate to ascertain the cause of 71 lesions seen on SPECT in 29 patients. Twenty-six of these lesions were not seen on planar images. Of the 71 lesions, 44 were benign and 27 metastatic. Of the 15 lesions where the pedicle was involved, 11 were found to metastatic. There were a total of 14 facet lesions, 9 of which were present in vertebra with no lesions at sites other than the facets. All 9 of these isolated facet lesions turned out to be benign. Lesion intensity did not distinguish benign from malignant disease. We conclude that SPECT imaging is useful in determining the etiology of focal lesions seen on bone scan in patients with a known primary tumor referred for evaluation of metastatic disease.     

Bone marrow changes adjacent to the sacroiliac joints after pelvic radiotherapy mimicking metastases on MRI

Radiation-induced changes in the sacroiliac joints mimicking metastases on MR images were evaluated. Twelve patients who received radiotherapy to the pelvic region due to pelvic malignancy were included in the study. All patients had undergone external beam radiation therapy to the pelvic region, and 2 patients received supplementary internal radiation. The changes in the sacroiliac joints were evaluated. Computed-tomography-guided core bone biopsy from the bone marrow was taken from their corresponding MR sections in 5 of the patients. T1 hypointense and T2 hyperintense areas with ill-defined margins in the bone marrow adjacent to the sacroiliac joints were observed in all patients. On bone scintigraphy all the lesions demonstrated increased activity. Other radiological modalities excluded fracture, soft tissue mass, and osseous destruction. Bone biopsies demonstrated peritrabecular fibrosis and inflammatory cell infiltration. Patients receiving radiotherapy to the pelvis may demonstrate T1 hypointense/T2 hyperintense, ill-defined postradiotherapeutic benign changes in the sacroiliac joints. In the absence of any other signs of disease progression and when the imaging pattern is typical, close radiological follow-up should be sufficient to rule out metastases.     

Contrasting natural histories of thoracic spine pneumatocysts: resolution versus rapid enlargement

An intraosseous pneumatocyst is an unusual cause of gas in a vertebral body and is rarely reported in the thoracic spine. We report the evolution of thoracic spine pneumatocysts, one that enlarged rapidly with resorption of fluid and one that resolved. A 65-year-old female with lower back and left leg pain underwent MRI of the lumbar spine, which demonstrated a well-defined lesion in a T10 vertebral body of low-signal on T(1) and T(2) weighted imaging. CT confirmed this as a gas-containing cyst. Review of previous imaging showed that this lesion had initially contained fluid and had expanded rapidly over 14 months. It also showed smaller pneumatocysts, which had resolved. The variable natural history and imaging features of pneumatocysts make them an important differential diagnosis of an intravertebral lesion. Their aetiology is not known, but previous case reports suggest that they can occur spontaneously or in association with vacuum phenomenon in adjacent discs or facet joints. Previous reports have observed that they can fill with granulation tissue or fluid, and the case we report demonstrates that this fluid can be resorbed and that the pneumatocyst can undergo rapid enlargement. A pneumatocyst is a differential diagnosis for an expanding intravertebral lesion of indeterminate MRI characteristics. The diagnosis can be made with CT if the lesion is gas or gas and fluid filled.     

Anatomy and pathology of the aging spine

The vertebral column is a complicated anatomical structure which is composed of the intervertebral discs and the vertebrae. Both components develop special degenerative changes and morphologic features during life. This paper first reviews the anatomical fundamentals and then describes the morphological features of the aging intervertebral disc and the subsequent osseous changes of the vertebral bodies and the zygapophyseal joints. The aging intervertebral disc is characterised by processes which are labeled as intervertebral chondrosis and intervertebral osteochondrosis. Often these processes are combined with typical dislocations of intervertebral disc tissue in an anterior or dorsolateral direction. The well known Schmorl's nodules must also be mentioned in this context. Furthermore calcification and ossification of the intervertebral disc tissue can take place. More severe processes lead to osseous changes of the vertebral bodies. In particular, an osteophytosis of the vertebral bodies can be established. These sturdy osteophytes are able to stiffen the vertebral column. Furthermore the arthrotic changes of the zygapophyseal joints are delineated in this paper. The special appearances of these changes are discussed according to the different and specialised regions of the vertebral column. The advanced degenerative changes of the zygapophyseal and uncovertebral joints of the cervical spine are of essential clinical interest because the compression of the vertebral artery or the narrowing of the intervertebral foramina by these processes may cause severe neurological symptoms. The arthrotic changes of the medial atlantoaxial joint, which lead to the crowned odontoid, and the pseudospondylolisthesis (so called M. Junghanns) of the lumbar spine must also be mentioned. It is the aim of this paper, not only to explain and review the degenerative changes, but to illustrate the anatomy and pathology of the aging spine on the basis of macerated osseous specimens in order to make radiological investigations and pictures more understandable and clear.     

CT导向经皮穿刺椎体活检术在椎体病变中的诊断价值

目的探讨CT导向下经皮穿刺椎体活检技术及其对椎体病变定性诊断的价值。资料与方法62例椎体病变患者,男45例,女17例,单椎体病变38例,两椎体病变14例,多椎体病变10例。其中颈椎2例,胸椎28例,腰椎25例,骶尾椎7例。颈椎病变患者取仰卧位,胸、腰、骶椎病变患者取俯卧位。在CT横断扫描导向下,对病变部位穿刺活检,穿刺标本送病理学检查。结果62例患者均穿刺成功,52例(80.8%)成功取得病理组织并得到明确的病理结果,6例未取得病理组织,3例病理诊断不明确,1例不相符。行免疫组织化学检查10例,得到了明确的组织学诊断,4例恶性病变因细胞组织太少仍不能明确组织学特征。结论CT引导下椎体穿刺活检术,具有微创、安全、取材准确、可靠、方便等优点,是脊柱病变活检的理想方法,可以为临床提供可靠的组织学依据。     

The radiologic assessment of post-traumatic vertebral stability

The stability of the vertebral column depends upon the integrity of the bones, ligaments, and joints. The vertebral column can be divided into three distinct anatomic zones: anterior, middle, and posterior. Disruption of any single zone does not produce instability. Disruption of two contiguous zones will, however, significantly decrease the load-carrying capability of the spine and result in instability. Five radiographic signs indicative of vertebral instability have been identified: (1) displacement implies injury to major ligamentous and articular structures; (2) a wide interlaminar space implies injury to the posterior ligamentous structures and the facet joints; (3) wide facet joints imply injury to the posterior ligamentous structures; (4) a disrupted posterior vertebral body line implies burst injury with disruption of anterior bony and posterior ligamentous structures; (5) a wide vertebral canal implies injury to the entire vertebra in the sagittal plane. Each of these signs indicates disruption of a major skeletal, ligamentous, or articular structure and the presence of only one is sufficient to establish a diagnosis of instability. These conclusions are based upon a study of 138 injuries observed in 125 patients.     

MRI全景扫描在脊柱转移瘤中的应用

目的 探讨MRI全景扫描在脊柱转移瘤中的应用价值. 资料与方法 对25例怀疑有脊柱转移的患者,应用MRI全景扫描,行全身及全脊柱分段扫描后,采用对接方法 得到全身及全脊柱全景图像. 结果 25例均获得直观、准确地显示全身冠状位及全脊柱矢状位的连续图像,椎体单发转移瘤11例(颈段1例,胸段4例,腰段6例),椎体多发转移瘤14例(胸腰段6例,全脊柱8例).发现全景扫描前未发现的原发肿瘤8例. 结论 MRI全景扫描可以很好地显示脊柱转移瘤的部位、数目及邻近组织结构受侵的程度和范围,同时有利于原发病灶的发现,大大提高了定位及定性诊断的准确性.     

脊柱转移瘤在椎骨上的分布与血行播散模式(附68例分析)

目的：分析脊柱转移瘤的CT表现，探讨转移瘤在椎骨上的分布与血行播散模式的相关性。方法：68例经临床及组织学证实的脊柱转移瘤病人，每个椎骨在CT横断面上被分成18个部分，每个部分的病灶数被统计。结果：68例患者167个椎骨受累，共210个病灶，其中。196个定位于椎体，168个定位于椎体中后部，49个椎骨的椎弓根受到侵犯。结论：转移瘤在椎骨上的分布与血行播散模式相关(尤其是Batson静脉丛)，并且在鉴别诊断中也有意义。