Clinical experience with high-viscosity cements for percutaneous vertebral body augmentation: occurrence, degree, and location of cement leakage compared with kyphoplasty.

BACKGROUND AND PURPOSE: Vertebroplasty is known for its high leakage rate compared with kyphoplasty. In recent preclinical studies, high-viscosity cements were shown to significantly enhance the uniformity of cement filling and decrease the incidence of leakage in cancellous bonelike substrates compared with low-viscosity cements. In this study, the incidence and pattern of cement leakage by using a new high-viscosity cement (Confidence spinal cement system) was compared with that of standard kyphoplasty. MATERIALS AND METHODS: Postoperative radiographs of patients treated with either kyphoplasty or Confidence were analyzed for cement leakage by using a stringent and thorough 4-point scale (none, minimal, moderate, or severe). When leakage was observed, the location of the cement leakage was also recorded and described as diskal, venous, paravertebral, or epidural. Sixty-two consecutive patients with 112 treated levels were included in this retrospective review. There were 46 kyphoplasty- versus 66 Confidence-treated levels, which ranged from T3 to L5. RESULTS: The average vertebral collapse reached 27.9 +/- 20.7% in the Confidence group versus 25.0 +/- 19.1% in the kyphoplasty group. There was no or mild leakage in 92% of Confidence and 91% of the kyphoplasty cases (mild, 39% Confidence versus 50% kyphoplasty). Severe leakage was only reported in 1 (2%) Confidence and 1 (2%) kyphoplasty case. In both cases, the severe leakage was found in the disk space. No significant leakage that required any surgical intervention was noticed. CONCLUSIONS: This finding confirms prior observations that highly viscous cements may increase the safety of vertebral augmentation techniques compared with less viscous cements. The high-viscosity Confidence cement results in a leakage rate comparable with that of kyphoplasty.

Percutaneous cement augmentations of malignant lesions of the sacrum and pelvis.

BACKGROUND AND PURPOSE: Although cement augmentation has been described in the literature for the treatment of benign sacral insufficiency fractures, only a few case reports have described the procedure's usage in the treatment of malignant lesions. The purpose of this study was to evaluate the feasibility, effectiveness, safety, and clinical outcome for percutaneous cement augmentation of patients with malignant lesions in the sacrum and pelvis. MATERIALS AND METHODS: A prospective study of 12 patients (7 men and 5 women) with a median age of 64.5 years was conducted under appropriate institutional review board protocol. Patients had different types of malignant metastatic lesions of the sacrum and pelvic bones. All but 1 patient underwent preprocedure CT and MR imaging. All patients had a postprocedure CT, and all but 1 had sacral lesions. Six patients had a second lesion in the iliac bones. Under CT guidance, percutaneous cement augmentation was performed in 8 cases and under fluoroscopy guidance in 2 cases. In 2 cases, needles were placed under CT guidance, and the injection was performed under fluoroscopy. In 5 patients, a single needle was used; in another 5 patients, 2 needles were used. One patient had 3 needles, and another patient required 4 needles. RESULTS: Adequate cement deposition was seen in all cases. Three patients had minimal clinically insignificant cement leakage. All treated patients (except 1 patient) reported decreased pain level with use of the visual analog scale (VAS) within 2 to 4 weeks of follow-up. No other subsequent surgical interventions were required. CONCLUSIONS: Percutaneous cement augmentation of metastatic lesions of the sacrum and pelvic bones is a feasible and safe technique that can be performed under CT or fluoroscopic guidance. The technique results in decreased pain relief on short-term follow-up that can allow patients to tolerate future treatment.

Bone cement deposition patterns with plasma-mediated radio-frequency ablation and cement augmentation for advanced metastatic spine lesions.

BACKGROUND AND PURPOSE: Combining percutaneous plasma-mediated radio-frequency (pmRF) ablation with vertebral body augmentation offers an alternative treatment to surgical intervention options for advanced metastatic spinal lesions and is particularly useful for cases with cortical destruction and/or epidural extension. This study evaluates bone cement deposition patterns and extravasation in treated vertebral bodies in relation to the metastatic lesion after using this combined approach. MATERIALS AND METHODS: Retrospective assessments of CT images performed before/after the procedures were evaluated in 37 patients (44 levels) with advanced metastatic lesions. A void was created in the anterior portion of the tumor-infiltrated vertebral body by using a bipolar plasma-mediated radio-frequency-based wand, followed by deposition of bone cement. Pain measured by visual analog scale score was recorded preprocedure and 2-4 weeks afterward. RESULTS: In 19 (43%) levels, 90%-100% of the cement was deposited in the anterior two thirds of the vertebral body. In 34 levels (77%), 75% or more of the cement was deposited in the anterior two thirds of the vertebral body. In 13/15 (86%) levels with posterior lesions, cement was deposited anterior to the lesion. No extravasation was observed in 13 levels (29.5%). Two clinically insignificant incidences of epidural extravasation were noted. Pain relief after the procedure was reported by 25/28 (89.5%) patients with available data. CONCLUSIONS: pmRF ablation may allow greater cement-deposition control, increasing the likelihood of successfully stabilizing the anterior two thirds of the vertebral body. This combined technique appeared particularly useful in cases with posteriorly located lesions. The incidence of cement extravasation was relatively high but clinically insignificant.

Metastatic spinal lesions: state-of-the-art treatment options and future trends.

The purpose of this article is to review the current state of the art for treating symptomatic spinal fractures associated with malignant lesions and to present potential future trends in treatments for this patient population. Epidemiology, clinical presentation, and biomechanical ramifications of these lesions are summarized and treatment regimes, clinical outcomes, and complications and technical issues associated with treatments are presented. Potential future trends and new technologies for performing vertebral body augmentation in patients with metastatic spinal lesions are also discussed.

Plasma-mediated radiofrequency ablation assisted percutaneous cement injection for treating advanced malignant vertebral compression fractures.

BACKGROUND AND PURPOSE: Using percutaneous cement injection to treat vertebral compression fractures (VCF) stemming from advanced malignancy, particularly those showing posterior cortical defect and epidural extension, is associated with higher risk of complications compared with treating benign osteoporotic VCF. The purpose of this study was to examine the clinical feasibility of a technique designed to improve control of cement placement. MATERIALS AND METHODS: A prospective series of patients (n = 15) with metastatic lesions having epidural extension of tumor and/or cortical disruption were treated. The percutaneous procedure consisted of using a plasma-mediated radio-frequency-based device to etch a cavity within the affected vertebral body and filling the cavity and adjacent interstices with bone cement. Change in pain status was determined by asking the patient to grade back pain preoperatively and at the 2-4-week postprocedure examination using a visual analog scale. RESULTS: An adequate amount of cement was injected in all cases. Extraosseous extension of cement was observed in 4 cases (anterior cortex, n = 3; through neural foramen, n = 1) but was clinically inconsequential. No thermal or neuronal insult was observed during the procedure in any case. Thirteen of the 15 (87%) patients reported decreased pain. CONCLUSION: Dissolution of tissue rather than displacement to create a cavity before injecting bone cement permitted well-directed cement deposition into the compromised vertebral body, which may allow a safer procedure to be conducted in patients with advanced malignant VCF. Clinical benefits may include avoiding more extensive surgery and reducing the risk of complications associated with conventional bone cement injection procedures.

Neuroradiologic findings in Marinesco-Sjögren syndrome.

PURPOSE: Our purpose was to determine the neuroradiologic findings of Marinesco-Sjögren syndrome on plain skull radiographs, CT, and MR images. METHODS: Eight patients with proved Marinesco-Sjögren syndrome (age range, 4 to 56 years) had a total of nine CT scans, seven MR imaging studies, and two plain radiographic examinations of the skull. The findings were reviewed retrospectively, with particular attention to the size of the posterior fossa and cerebellum. RESULTS: All patients had hypoplastic cerebellar hemispheres and a hypoplastic vermis in a small posterior fossa. One patient had a midline posterior fossa cyst and another had agenesis of the corpus callosum. CONCLUSION: Hypoplasia of the cerebellar hemispheres and the vermis and a small posterior fossa are the most prominent neuroradiologic findings in Marinesco-Sjögren syndrome.

Quantitative analysis of signal intensities and contrast after fat suppression in contrast-enhanced magnetic resonance imaging of the spine.

RATIONALE AND OBJECTIVES: We studied the effect of fat suppression on signal intensity and contrast on contrast-enhanced magnetic resonance (MR) images of the spine. METHODS: Contrast-enhanced T1-weighted MR images were obtained at identical levels with and without fat suppression. Signal intensity and contrast were measured in regions of interest in fat, muscle, spinal bone marrow, and enhancing lesions. The differences in the mean values of these signal intensities and the mean values of contrast between enhanced tissues and bone marrow, fat, and muscle were subjected to statistical validation. RESULTS: Mean signal intensity of the extraspinal fat and bone marrow was lower after fat suppression (70% and 46% reduction, p < .001 and p < .05, respectively), whereas the signal intensity of muscle showed no significant change (p < .9). Enhancing spinal lesions showed a difference in mean signal intensity after fat suppression (22% increase, p < .2). Contrast between enhanced lesions and bone marrow and fat was higher after fat suppression (78% increase, p < .01 for bone marrow; 8% increase, p < .001 for fat). CONCLUSION: In contrast-enhanced MR examinations of the spine, the use of fat suppression may increase the signal intensity of the enhancing lesion by expanding the dynamic gray scale of the image and increases the contrast between the lesion and adjacent bone marrow and suppressed fat.

MR imaging of spinal nerve roots: techniques, enhancement patterns, and imaging findings.

The purpose of this report was to review the MR techniques, contrast enhancement patterns, and MR imaging findings for the spinal nerve roots. The phenomenon of contrast enhancement of the nerve roots and its relationship to disk disease and failed-back-surgery syndrome are discussed. The MR imaging findings for various inflammatory and neoplastic disorders affecting the spinal nerve roots are described and illustrated.

Fat-suppression contrast-enhanced MRI in the failed back surgery syndrome: a prospective study.

We examined 25 patients with recurrent pain after lumbar disk surgery with MRI to evaluate the usefulness of gadolinium (Gd)-enhanced fat-suppression (FS) imaging in patients with failed back surgery. Pulse sequences included T1-weighted (T1W) images, Gd-enhanced T1W images, and Gd-enhanced T1W images with FS. The addition of FS to Gd-enhanced T1W images improved visualization of enhancing scar in all cases, helped distinguish scar from recurrent herniated disk, and showed more clearly the relationship of scar to the nerve roots and thecal sac. The images also demonstrated enhancement of the facet joints and theca in 23 and 11 cases, respectively. Intradural nerve roots were more conspicuous with FS in 21 cases. The combination of unenhanced and Gd-enhanced T1W images with FS is recommended for routine examination of the postoperative back.

MR imaging of the spine: recent advances in pulse sequences and special techniques.

A number of new techniques have been developed to enhance MR imaging of the spine. Fat-suppression techniques used in conjunction with gadolinium-based contrast material improve visualization of enhancing inflammatory and neoplastic diseases. Fast spin-echo (FSE) sequences can be used to decrease imaging times, to increase resolution, or to improve signal-to-noise ratios on T2-weighted images. In general, FSE images provide a better myelographic effect with reduced magnetic susceptibility compared with gradient-recalled echo (GRE) techniques. With volume GRE sequences, thin contiguous sections can be obtained, and images can be reformatted into multiple planes from a single data set. High-contrast imaging can be accomplished by using three-dimensional (3D) turbo-fast low-angle shot (FLASH) or magnetization prepared rapid acquisition gradient-echo (MP RAGE) techniques with gadolinium contrast enhancement. Finally, CSF flow dynamics within the subarachnoid space and within cystic lesions can be elucidated with phase-contrast techniques. Judicious selection of these methods and other innovative MR techniques is necessary to maximize the potential of MR in diagnosis of spinal disease.

Evaluation of fat suppression in contrast-enhanced MR of neoplastic and inflammatory spine disease.

PURPOSE: To determine the benefit of fat suppression in conjunction with gadolinium enhancement for evaluating neoplastic and inflammatory diseases of the spine. METHODS: Contrast-enhanced T1-weighted images were compared with the corresponding contrast-enhanced T1-weighted images with fat suppression in 14 patients with various neoplastic and inflammatory spine diseases. RESULTS: Contrast-enhanced T1-weighted images with fat suppression showed enhancing lesions in all cases of vertebral disease (five cases), but in one case some metastases did not enhance. Paravertebral (nine lesions), epidural (seven lesions), and intradural-extramedullary (six lesions) were delineated better with contrast-enhanced fat suppression. In the 14 cases (29 lesions), nine lesions were seen only on contrast-enhanced images with fat suppression. Integrity of the vertebral end plates was assessed more accurately on fat-suppressed images. CONCLUSION: Although noncontrast T1-weighted images are sufficient to screen for vertebral disease, contrast-enhanced images with fat suppression may detect additional lesions. Fat suppression should be used in conjunction with gadolinium for evaluating epidural, paravertebral, and intradural-extramedullary spinal lesions.

MR of the spine in Guillain-Barré syndrome.

MR examination of the spine after injection of gadopentetate dimeglumine showed enhancement of the cauda equina in a case of Guillain-Barré syndrome. These MR observations may help confirm the diagnosis of Guillain-Barré syndrome.

MR imaging of the corpus callosum.

The corpus callosum is the major axonal commissure of the brain, connecting the two cerebral hemispheres and providing communication between the cortical and subcortical neurons. With MR imaging in the sagittal plane, the corpus callosum can be depicted in great detail. We review the normal anatomy, development, and process of myelination of the corpus callosum. The MR features of various pathologic conditions involving the corpus callosum are described. Finally, we discuss the evolving role of MR imaging in neuropsychiatric diseases with respect to the corpus callosum.