Pathologic vertebral compression in spinal malignancy secondary to intervertebral disk expansion.

A retrospective analysis of the MR appearance of the intervertebral disks in 17 patients with spinal malignancy was performed. Disk expansion, related to neoplastic structural weakening of the bone in the face of unaltered disk biomechanics, was present in 20% of all visualized disks in association with a 77% incidence of malignant involvement of the vertebral bodies studied. This compared with a frequency in benign disk expansion (i.e., osteoporosis) of 2% in the age-matched, but randomly selected, control group. On careful review, there was no strict correlation between disk expansion and patient symptoms. Although this finding may be seen in non-neoplastic conditions, it is felt that the higher incidence of disk expansion associated with osseous vertebral malignancy nevertheless reflects the underlying gravity of the pathologic changes accompanying neoplasia.     

压缩性骨折椎体真空征的病理与影像表现对照研究

目的 研究压缩性骨折椎体真空征(intravertebral vacuum phenomenon,IVP)的影像表现.方法 对209例椎体压缩性骨折行经皮椎体成形术(percutaneous vertebroplasty,PVP)与经皮椎体后凸成形术(percutaneous kyphoplasty,PKP)患者常规实施椎体组织活检.所有患者术前行常规X线、CT、MR检查,评价IVP与病理学结果的一致性及IVP诊断压缩性骨折椎体骨坏死的阳性预测值、阴性预测值、特异度、敏感度及Youden指数,对IVP与骨坏死一致性行Fisher确切概率法检验.结果 病理学检查,209例椎体压缩性骨折中单纯骨质疏松146例(69.9%),骨质疏松合并骨坏死10例(4.8%),恶性肿瘤53例(25.4%).术前影像检查发现10例IVP,常规X线检查显示椎体线性透亮区,CT能更好显示椎体内积气,MR T_1WI均表现为低信号,随患者仰卧时间不同,T_2WI信号可有多种变化,其中9例病理学检查发现骨坏死;病理学检查10例骨坏死中9例有IVP,1例影像仅表现为骨质疏松征,IVP与病理学诊断有明显相关性(P<0.01).IVP诊断骨坏死的阳性预测值为90.0%(9/10),阴性预测值为99.5%(198/199),敏感度为90.0%(9/10),特异度为99.5%(198/199),Youden指数为0.9.结论 压缩性骨折椎体中出现IVP,提示椎体局部骨出现坏死.     

The intravertebral vacuum phenomenon or gaseous dissection of the vertebral body

The intravertebral vacuum phenomenon is rather uncommon. It is determined by the collapse of the body of the vertebra with successive aspiration ex vacuo of gas (nitrogen) from the surrounding tissues, which collects under the endplates, causing them to appear disconnected. To date, the one who has reported the highest number of cases is Maldague, with sixty examples. Our report concerns four cases seen during the past five years. According to the most widely accepted pathogenetic theory, this phenomenon represents, together with vertebral collapse and increased bone density, a pathognomonic sign of ischemic osteonecrosis of the vertebrae, similar to osteonecrosis of the head of the thigh bone and, like this, favored by many different factors, such as old age, repeated traumas, alcoholism, rheumatoid arthritis, arteriosclerosis and corticosteroid therapy.     

Degenerative lumbar disk disease: pitfalls and usefulness of MR imaging in detection of vacuum phenomenon

Magnetic resonance (MR) images of the lumbar spine from 150 patients were retrospectively reviewed. In 14 of these patients, at 18 disk levels, a vacuum phenomenon (VP) had been identified on plain radiographs and/or computed tomographic scans. The MR imaging appearance of these gas collections in 17 disks was an area without signal, best seen on spin-echo sequences with short repetition time and echo time in the sagittal view. MR imaging precisely located the VP in the anulus fibrosus, the nucleus pulposus, and Schmorl nodes. In all but one case, degeneration of the disk was complete and associated with adjacent changes in vertebral bone. Pitfalls of MR imaging detection of VP included chemical shift artifact, calcifications, and tears without gas in the disk.     

Intervertebral disk cyst: a case report

This case describes a patient who presented with chronic low back pain which developed over the course of 1 year. Imaging revealed a 1.1-cm cystic lesion at the L4-L5 vertebral level posterior to the intervertebral disk. Following both magnetic resonance and computed tomography imaging, diagnosis of intervertebral disk cyst was confirmed by both imaging modalities. A computed tomography-guided aspiration of the lesion was performed, and the patient was given a course of steroid injections with complete resolution of the lesion.     

经皮椎体后凸成形术治疗伴椎体内真空征的骨质疏松性椎体骨折和塌陷

目的 探讨经皮椎体后凸成形术(percutaneous kyphoplasty,PKP)治疗伴椎体内真空征的骨质疏松性椎体骨折和塌陷的临床疗效. 方法 回顾性分析2009年6月-2011年6月应用PKP治疗的31例伴椎体内真空征的骨质疏松性椎体骨折和塌陷患者的临床资料,分析本组患者的临床及影像学特点,通过测量术前、术后1周、术后3～6个月随访时骨折椎体高度变化,同时采用视觉模拟评分(visual analogue scale,VAS)和Oswestry功能障碍指数(Oswestry disability index,ODI)评价PKP的临床疗效. 结果 31例患者均顺利完成手术,术后24 h内患者腰背部疼痛均有明显缓解.术后1周和术后3～6个月随访时骨折椎体的高度分别为(17.2±4.2) mm、(16.8±5.1) mm,与术前(11.4±1.7)mm比较差异均有统计学意义(P＜0.01),两次随访差异无统计学意义(P＞0.05).术后1周VAS评分、ODI分别为(2.8±1.7)分、31.6±8.4,与术前(8.6±1.3)分、78.3±8.5比较差异均有统计学意义(P＜0.01),术后3～6个月随访VAS评分、ODI分别为(2.3±0.8)分、(23.7±2.3),与术前比较差异有统计学意义(P＜0.01),与术后1周比较差异无统计学意义(P＞0.05). 结论 PKP治疗伴椎体内真空征的骨质疏松性椎体骨折和塌陷患者,可有效缓解疼痛,恢复骨折椎高度,具有良好的临床效果.     

Intervertebral disk: normal age-related changes in MR signal intensity

The effect of age on the signal intensity of normal lumbar intervertebral disks was studied. Twenty-seven cadavers ranging in age from newborn to 79 years were studied with use of a 1.5-T magnetic resonance (MR) imager within 48 hours of death. The signal intensity in the central area of the disk was measured on a sagittal image obtained with a long repetition time (TR) and a long echo time (TE) and correlated to the age. A significant correlation between the decrease in signal intensity and age was found, although signal intensity changed less than 6% in 80 years. The decrease in signal intensity is concomitant with decreases in water and glycosaminoglycans and increases in collagen in the disk.     

Osteoporotic vertebral collapse: percutaneous vertebroplasty and local kyphosis correction

Forty-six cases of osteoporotic vertebral collapse (27 thoracic, 19 lumbar) were treated by means of percutaneous vertebroplasty in a hyperlordosis position. Institutional review board approval and informed consent were obtained. Kyphosis reducibility was preprocedurally estimated from the angular difference between neutral and hyperlordosis positions. Effective reduction was the angular difference in neutral positions before and after vertebroplasty. Reduction (< or =14 degrees ; mean, 6.43 degrees) was obtained in cases with estimated reducibility greater than 5 degrees (31 cases, 67%), which is a 34% (6.5 degrees of 19.1 degrees ) mean reduction. A significantly greater level of kyphosis reduction was observed in cases with intravertebral clefts (20 cases, 43%) at hyperlordosis than in those without (7.2 degrees vs 4.9 degrees ; P < .01). Vertebroplasty may reduce kyphosis due to localized collapsed vertebrae; intravertebral mobility and cleft suggest this possibility.     

Intervertebral disk calcification of the spine in an elderly population: radiographic prevalence, location, and distribution and correlation with spinal degeneration

PURPOSE: To determine the prevalence, distribution, and location of intervertebral disk calcification (IDC) in the thoracic and lumbar spine and the association of IDC with radiographically evident spinal degenerative changes in cadavers. MATERIALS AND METHODS: Anterior vertebral columns comprising T1 through L5 were removed from 223 cadavers (183 men, 40 women; mean age at death, 67 years; range, 37-94 years). Approximately 5-mm-thick parasagittal sections were investigated with high-contrast radiography. The presence of IDC, osteophytes, vertebral endplate abnormalities, and vacuum phenomena was recorded, and the height of disk space was measured at 3,568 intervertebral levels. Logistic regression analysis was performed. RESULTS: IDC was identified in 178 (80%) of the 223 cadavers. Of 3,568 disks, 459 (13%) had IDC, and 289 cases (63%) were located in the annulus fibrosus. IDC was most common in the lower thoracic spine, occurring in 275 (60%) of 459 disks. IDC occurred in 159 (87%) of 183 men and 19 (48%) of 40 women. Logistic regression analysis was adjusted for age, and results showed that the frequency of IDC was significantly higher in men in upper, middle, and lower segments of the thoracic spine (P <.05) but not in the lumbar spine (P =.09). IDC correlated with increasing age (P <.001) and disk space loss (P <.001) at all spinal levels. There was no association of IDC with vacuum phenomena or vertebral endplate abnormalities at any spinal level. CONCLUSION: IDC is common in elderly persons, especially in the annulus fibrosus and lower thoracic spine. The prevalence of IDC increases with age and extent of disk space loss.     

Acute bilobar collapse secondary to endobronchial metastatic seminoma

We report here a patient with tracheal and endobronchial metastatic seminoma who presented with acute respiratory failure with right upper and middle lobe collapse. Diagnosis of the etiology of the atelectasis was made by fiberoptic bronchoscopy. Radiation therapy caused a marked reversal of the atelectasis.     

Diffuse vertebral body edema due to calcified intraspongious disk herniation

We describe the case of a patient with a recent history of high back pain, with magnetic resonance imaging (MRI) of the thoracic spine showing intervertebral disk herniation into the spongious bone of the vertebral body of T9 that might have caused diffuse, low signal intensity on fluid-attenuated inversion recovery T1-weighted (FLAIR-T1W) images, high signal intensity magnetic resonance (MR) on T2-weighted (T2W) images and T2-weighted fat-suppressed images (T2W-FSIs) and marked enhancement on the vertebral body of T9 with gadolinium on T1-weighted fat-suppressed images (T1W-FSIs) images. Those findings suggested diffuse edema and might be indistinguishable from tumoral or inflammatory diseases, but the plain films and the reformatted sagittal computed tomography scans of the thoracic spine were helpful to show a calcified part of the intervertebral disk migrating into the vertebral body of T9. The patient made full recovery from the symptoms after conservative treatment and at the follow-up MRI showed normalization of the bone marrow signal intensity of the vertebral body of T9.     

The vacuum phenomenon: a CT sign of nonunited fracture

OBJECTIVE: The purpose of this study was to describe on CT scans the presence of a gas collection within a bone fracture reflecting the vacuum phenomenon as a sign of nonunited fracture. CONCLUSION: A gas collection between fractured bone fragments suggests a nonunited fracture.     

Intravertebral vacuum phenomenon following fractures: CT study on frequency and etiology

PURPOSE: The purpose of this work was to determine the frequency and etiology of the intravertebral vacuum phenomenon (IVP). METHOD: CT examinations of 96 vertebral fractures were evaluated for IVP. Bone mineral density (BMD) was determined in nonfractured vertebrae. For calibration purposes, densities of a standard phantom measured in 30 patients who underwent quantitative CT examinations in the same time period were used and precision was calculated. RESULTS: Eleven of 96 fractures (11.5%) showed IVP. IVP was present in 4 of 20 fractures at T12 (20%), in 4 of 23 at L1 (17.4%), and 1 IVP was found at L2-4 each. Mean +/- SD age of patients with IVP was 68.3 +/- 10.5 years and without 47.8 +/- 19.4 years (p < 0.001). Mean +/- SD density of nonaffected vertebra was 45.9 +/- 17.0 mg of hydroxyapatite/ml for patients with IVP and 139.5 +/- 62.6 mg/ml for those without IVP (p < 0.0005). An average precision of 1.2% was calculated for the density measurements over the investigated time. CONCLUSION: Following vertebral fractures, IVP on CT scans is more common than presumed and increases with age. There exists a significant inverse correlation between the BMD and the frequency of IVP.     

The spinal vacuum phenomenon. Radiographic and tomodensitometry aspects

The spinal vacuum phenomenon is readily recognized by computed tomography: there fore its observation has become frequent enough. The side of the gaseous collection (intervertebral disk, vertebral body, apophyseal joint) depends on the disease inducing the phenomenon. Radiological and CT aspects of this findings are discussed. The usefulness of vacuum phenomenon in the diagnosis of several pathological conditions is examined.