Reliability of a modified Modic classification of bone marrow changes in lumbar spine MRI

ObjectiveThe purpose of this study was to determine the intra- and interobserver reliability of a modified Modic classification for bone marrow changes seen on lumbar spine magnetic resonance imaging (MRI), taking into consideration mixed signals.MethodsLumbar MRI scans from 94 patients with low back pain were assessed independently by 2 spine specialists (senior [senior1], junior) and a radiologist (senior2). One reviewer (senior1) assessed the MR images twice at a three-week interval for evaluation of intraobserver reliability. Senior2 and junior reviewers assessed the MR images once. Pure edema endplate signal changes were classified as Modic type I, and pure fatty endplate changes as Modic type II. A mixture of types I and II but predominantly edema signal changes was classified as Modic I-2 and a mixture of types I and II but predominantly fatty changes was classified as Modic II-1.ResultsThe intraobserver agreement was excellent (weighted kappa 0.85). The interobserver agreement was moderate to substantial (weighted kappa range 0.56–0.74). Interobserver reliability depended on the experience of the observer, thus highlighting the importance of a learning curve.ConclusionThis study shows that the modified Modic classification is reliable and easy to apply for observers with different clinical experience. The inclusion of mixed marrow changes in the modified classification may have clinical and therapeutic implications.     

Vertebral end-plate (Modic) changes on lumbar spine MRI: correlation with pain reproduction at lumbar discography

The vertebral end-plate has been identified as a possible source of discogenic low back pain. MRI demonstrates end-plate (Modic) changes in 20–50% of patients with low back pain. The aim of this study was to investigate the association between Modic changes on MRI and discogenic back pain on lumbar discography. The MRI studies and discograms of 58 patients with a clinical diagnosis of discogenic back pain were reviewed and the presence of a Modic change was correlated with pain reproduction at 152 disc levels. Twenty-three discs with adjacent Modic changes were injected, 21 of which were associated with pain reproduction. However, pain was also reproduced at 69 levels where no Modic change was seen. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for a Modic change as a marker of a painful disc were 23.3%, 96.8%, 91.3% and 46.5% respectively. Modic changes, therefore, appear to be a relatively specific but insensitive sign of a painful lumbar disc in patients with discogenic low back pain. Received: 24 October 1997 Revised: 11 March 1998 Accepted: 21 April 1998     

The ‘Lumbar Fusion Outcome Score’ (LUFOS): a new practical and surgically oriented grading system for preoperative prediction of surgical outcomes after lumbar spinal fusion in patients with degenerative disc disease and refractory chronic axial low back pain

In order to evaluate the predictive effect of non-invasive preoperative imaging methods on surgical outcomes of lumbar fusion for patients with degenerative disc disease (DDD) and refractory chronic axial low back pain (LBP), the authors conducted a retrospective review of 45 patients with DDD and refractory LBP submitted to anterior lumbar interbody fusion (ALIF) at a single center from 2007 to 2010. Surgical outcomes - as measured by Visual Analog Scale (VAS/back pain) and Oswestry Disability Index (ODI) - were evaluated pre-operatively and at 6 weeks, 3 months, 6 months, and 1 year post-operatively. Linear mixed-effects models were generated in order to identify possible preoperative imaging characteristics (including bone scan/99mTc scintigraphy increased endplate uptake, Modic endplate changes, and disc degeneration graded according to Pfirrmann classification) which may be predictive of long-term surgical outcomes . After controlling for confounders, a combined score, the Lumbar Fusion Outcome Score (LUFOS), was developed. The LUFOS grading system was able to stratify patients in two general groups (Non-surgical: LUFOS 0 and 1; Surgical: LUFOS 2 and 3) that presented significantly different surgical outcomes in terms of estimated marginal means of VAS/back pain (p?=?0.001) and ODI (p?=?0.006) beginning at 3 months and continuing up to 1 year of follow-up. In conclusion,  LUFOS has been devised as a new practical and surgically oriented grading system based on simple key parameters from non-invasive preoperative imaging exams (magnetic resonance imaging/MRI and bone scan/99mTc scintigraphy) which has been shown to be highly predictive of surgical outcomes of patients undergoing lumbar fusion for treatment for refractory chronic axial LBP.     

Predictive value of MRI vertebral end-plate signal changes (Modic) on outcome of surgically treated degenerative disc disease. Results of a cohort study including 60 patients

OBJECTIVE: To assess the predictive value of MRI vertebral end-plate changes (Modic) on clinical outcome of surgically treated lumbar single-level degenerative disc disease (DDD). METHODS: A cohort of 60 patients was included. Patient groups were similar in respect of age, gender and clinical presentation, allowing comparisons. Patient age ranged from 30 to 72 years (mean: 45.8 years). All patients suffered severe chronic low back pain for more than 6 months, with single-level symptomatic DDD. All patients experienced segmental instrumented interbody (n = 22) or posterolateral (n = 38) fusion. Clinical outcome was assessed by using a visual analog scale (VAS) and the functional disability scale of the Japanese Orthopaedic Association (JOA) for lumbar spine. The number of patients for each Modic group was as follows: Modic type 0, n = 15; Modic type I, n = 22; Modic type II, n = 14; and Modic type I/II, n = 9. Fusion rates were similar for each Modic group of patients. Mean follow-up was 14 months. RESULTS: The pre-operative mean VAS improved by 53.5% (from 8.2+/-2.0 to 3.8+/-1.9, p < 0.05) and the pre-operative mean JOA score by 58% (from 5.5+/-2.1 to 11.0+/-2.4, p < 0.05). Patients harboring Modic type I changes improved much better than others (p < 0.05). Conversely, clinical outcome of patients presenting with Modic type II lesions was poor. CONCLUSION: This study confirms instrumented fusion as an effective treatment in symptomatic lumbar DDD. Preoperative combination of low back pain of discal origin and severe DDD with Modic type I lesion on MRI may lead to excellent results after fusion in a large proportion of patients. Conversely, arthrodesis for patients harboring Modic type II abnormalities implicates smaller benefit of doubtful clinical significance.     

无症状成年中国人腰椎间盘MR影像分析

目的探讨无症状中国人腰椎间盘MRI征象及其临床意义。方法选取117例(585个椎间盘)21～59岁无症状中国成年人的腰椎MRI资料,采用盲法对MRI中椎间盘退变、椎间盘疝(膨出、突出、脱出和髓核游离)、局限性高信号区(HIZ)和Modic改变进行评价,并进行统计分析。结果 20～29岁患者中退变1～2级椎间盘约占89.09%(49/55),在50～59岁患者中降至20.51%(40/195),退变4、5级椎间盘所占比例分别为7.27%(4/55)和37.44%(73/195)。椎间盘膨出53例(53/117,45.30%),HIZ 40例(40/117,34.19%),椎间盘突出31例(31/117,26.50%)。患者ModicⅡ型改变发生率10.26%(12/117),高于Ⅰ型(2/117,1.71%,χ2=7.597,P<0.01)。未见髓核游离和ModicⅢ型改变。椎间盘疝、Modic改变和HIZ多发生于下腰椎。椎间盘疝的发生率随年龄增长显著升高(χ2=36.92,P<0.001)。Modic改变常见于30岁以上人群。HIZ在40～59岁相对高发。结论无症状国人腰椎间盘MRI以生理性退变表现为主;椎间盘脱出、ModicⅠ、Ⅱ型改变可能与腰痛症状相关。     

Effect of major axial skeleton trauma on preexisting lumbosacral spondylolisthesis.

The incidental occurrence of lumbar spine fractures in individuals with preexisting first degree lumbosacral isthmic spondylolisthesis may be looked upon as a simulated in vivo biomechanical experiment testing the stability of the lumbosacral subluxation. Among 200 patients with thoracolumbar spine fractures managed at the author's institution during the period of 1980-1989, five such cases were collected. All patients had a grade I isthmic spondylolisthesis at the L5-S1 level, and all sustained a burst fracture of the lumbar spine. In two patients, there was a previous history of low back pain and lumbosacral spondylolisthesis. In the other three patients, the olisthesis was judged to be old by a negative 99mTc-MDP bone scan, whereas the fractured vertebra showed intense uptake and/or by the negative operative findings at L5-S1 level during surgery. It was found that the incidence of lumbosacral spondylolisthesis in patients with thoracolumbar fractures was smaller than in the general population but the difference was not statistically significant (p = 0.213). In addition, it is concluded that mild lumbosacral spondylolisthesis can absorb considerable axial loading without an ascertainable evidence of damage.     

腰椎间盘退变性疾患下腰椎终板形态的MRI观察

【摘要】　目的：在MRI片上观察腰椎间盘退变患者下腰椎终板形态的分布规律,分析终板形态和椎间盘退变的关系。方法：回顾分析两组腰椎间盘退变性疾病患者的术前腰椎MRI,A组110例为单节段腰椎间盘突出症患者,B组35例为椎间盘源性腰痛患者。根据正中矢状面MRI T1像,将终板形态分为凹面、平坦、不规则三型;根据Pfirrmann法评定椎间盘退变程度并将Ⅰ～Ⅴ级分别计为1～5分;按Modic改变分级标准判定各节段终板有无Modic改变。分析下腰椎终板的形态特点及三种分型与椎间盘退变程度、Modic改变等的关系。结果：①435个下腰椎节段中,凹面型终板最多（215/435）,A组中占50.6％（167/330）,B组中占45.7％（48/105）,且主要分布于L3/4（108/215）、L4/5（83/215）节段;平坦型终板占29.0％（126/435）,并主要位于L5/S1节段（76/126）;不规则型终板最少（94/435）,A组中占23.0％（76/330）,B组中占17.1％（18/105）,也主要位于L5/S1节段（45/94）。②A组患者中,凹面型终板退变程度平均为3.31±0.81分,平坦型为3.66±0.64分,不规则型为4.16±0.67分,两两比较有显著差异（P＜0.05）;椎间盘突出节段以平坦型（37/110）和不规则型（43/110）终板占多数,无突出节段则以凹面型（137/220）终板占多数,差异有显著性（P＜0.05）;不规则型终板比凹面型和平坦型更容易伴发Modic改变,差异有显著性（P＜0.05）,凹面型和平坦型间无显著性差异（P＞0.05）。③B组患者中,凹面型终板的椎间盘退变程度平均为3.23±0.86分,平坦型为3.54±0.85分,不规则型为3.94±0.54分,仅凹面型和不规则型间差异有显著性（P＜0.05）。④相同终板形态时A组和B组椎间盘退变程度相比均无显著性差异（P＞0.05）。结论：终板形态与椎间盘退变、Modic改变之间有相关性。终板形态由凹面型到平坦型再到不规则型,腰椎间盘退变程度逐渐加重。影像学上终板形态改变在一定程度上反映了椎间盘退变的程度。     

Added value of SPECT/CT in patients suspected of having bone infection: preliminary results

AIM: We evaluated the contribution of SPECT/CT as an adjunct to combined three-phase bone scintigraphy (planar and SPECT) for diagnosing and localizing bone infection. Subsequently, the diagnostic performance of SPECT/CT was compared to visual fusion of SPECT with data of additional CT, X-ray, or MRI studies (SPECT + CT/X-ray/MRI). MATERIALS AND METHODS: Thirty-one patients suspected of bone infection, presenting pathological findings on triple-phase bone scintigraphy, underwent additional SPECT/CT. The SPECT/CT-technology combines the acquisition of SPECT and CT data with the same imaging device enabling perfect overlay of anatomical and functional images. (99m)Tc-DPD was used as radiopharmaceutical in all patients. For data analysis findings of bone scintigraphy (planar scans as well as SPECT) were categorized as positive, negative, or equivocal for the presence of osteomyelitis. In a second step, they were compared with SPECT/CT and SPECT + CT/X-ray/MRI with respect to localization and classification of lesions. Validation was achieved by surgery, biopsy, or by clinical follow up over at least 9 months including microbiological and radiological findings. RESULTS: Three-phase bone scan (incl. SPECT) correctly classified 7 lesions as positive and 11 lesions as negative for osteomyelitis. Six scans were interpreted false positive, two false negative, and five as equivocal. Rating the latter as positive for osteomyelitis, sensitivity of bone scan was (78%), specificity (50%). SPECT/CT was true positive in 7 patients, and true negative in 19. There were two false positive and two false negative findings, one scan was equivocal (sensitivity 78%, specificity 86%). Definition of anatomical localization of inflammatory foci was much easier by SPECT/CT due to better depiction of underlying anatomical details. SPECT + CT/X-ray/MRI yielded the highest sensitivity (100% compared to 78% of SPECT/CT), if equivocal findings (5/31 compared to 1/31 for SPECT/CT) are rated as true positive for osteomyelitis. Among radiological techniques, MRI (2 x FP) and CT (2 x FN) proved equal and expectedly superior to X-ray in delivering the correct diagnosis. CONCLUSION: SPECT/CT improves the diagnostic performance of three-phase bone scan for osteomyelitis by avoiding false positive or equivocal results. An additional benefit over visual fusion of SPECT with X-ray, CT, or MRI studies could not be confirmed in our study.     

Importance of correlating static and dynamic imaging studies in diagnosing degenerative lumbar spondylolisthesis

Degenerative spondylolisthesis in the lumbar spine is due to long-standing segmental instability. A standing plain radiograph is commonly the only imaging study needed to establish the diagnosis. Translatory motion in spondylolisthesis is traditionally assessed with lateral flexion and extension radiographs. These dynamic studies often demonstrate a decrease in the slip percentage between the vertebral segments with extension and an increase with forward flexion. Some low-grade spondylolisthetic deformities reduce anatomically on the operating table after the administration of an anesthetic. We encountered one case in which there was complete reduction of an L4-5 grade I degenerative spondylolisthesis with positioning of a non-anesthetized patient in the supine position during a lumbosacral magnetic resonance imaging (MRI) scan. The patient's condition was originally misdiagnosed, as the spondylolisthesis was not identified on recumbent plain radiographs or on lumbosacral MRI. This case stresses the importance of correlating static and dynamic imaging studies in developing a treatment plan for patients with degenerative spondylolisthesis.     

F-18 NaF PET for detection of bone metastases in lung cancer: accuracy, cost-effectiveness, and impact on patient management.

As bone metastases might be present in lung cancer despite a normal bone scan, we examined various alternatives prospectively. Positron emission tomography using F-18 sodium fluoride (PET) and single photon emission tomography (SPECT) were more sensitive than a planar bone scan. PET was more accurate with a shorter examination time than SPECT but had higher incremental costs. INTRODUCTION: Previous studies have shown that vertebral bone metastases not seen on planar bone scans may be present on F-18 fluoride positron emission tomography (PET) scan or single photon emission computed tomography (SPECT). The purpose of this study was to measure the accuracy, clinical value and cost-effectiveness of tomographic bone imaging. MATERIALS AND METHODS: A total of 103 patients with initial diagnosis of lung cancer was prospectively examined with planar bone scintigraphy (BS), SPECT of the vertebral column and PET using F-18 sodium fluoride (F-18 PET). Receiver operating characteristic (ROC) curve analysis was used for determination of the diagnostic accuracy. A decision-analysis model and the national charge schedule of the German Hospital Association were used for determination of the cost-effectiveness. RESULTS: Thirteen of 33 patients with bone metastases were false negative on BS, 4 on SPECT, and 2 on F-18 PET. The area under the ROC curve was 0.771 for BS, 0.875 for SPECT, and 0.989 for F-18 PET (p < 0.05). As a result of SPECT and F-18 PET imaging, clinical management was changed in 8 (7.8%) and 10 (9.7%) patients. Compared with BS, the costs per additional correctly diagnosed patient were 1272 Euro with SPECT and 2861 Euro with F-18 PET. The threshold for the costs of F-18 PET being more cost-effective than SPECT was 345 EUR. CONCLUSION: Routine performance of tomographic bone imaging improves the therapeutic strategy because of detection of otherwise missed metastases. F-18 PET is more effective than SPECT but is associated with higher incremental costs.     

腰痛患者下腰椎MRI上Modic改变与高信号区的发生情况及意义

目的:探讨腰痛患者下腰椎MRI上Modic改变与腰椎间盘局限性高信号区(high-intensity zone,HIZ)的发生情况及意义。方法:对511例腰痛患者(男263例,女248例;年龄20~70岁,平均48岁)腰椎MRI上L4/5和L5/S1节段的Modic改变和HIZ进行评估,统计两者及两者共存于同一节段的发生率。将有Modic改变和/或HIZ的椎间盘分为Modic组、Modic-HIZ组、HIZ组,比较3组的年龄、椎间盘高度、椎间盘退变程度、腰痛VAS和ODI评分。结果:511例患者中,190例(37.18%)209个节段有Modic改变,127例(24.85%)142个椎间盘有HIZ,18例(3.52%)18个节段出现Modic改变和HIZ共存的现象。HIZ组、Modic-HIZ组和Modic组分别为89例(124个节段)、18例(18个节段)、152例(191个节段),患者平均年龄分别为46.0±11.0岁、49.2±9.2岁和53.5±10.6岁,仅HIZ组和Modic组差异有统计学意义(P<0.05);椎间盘平均高度分别为9.93±2.46mm、8.73±2.45mm和7.57±2.21mm,组间两两比较差异有统计学意义(P<0.05);3组椎间盘退变分级均≥Ⅲ级,其中Ⅳ级+Ⅴ级退变率分别为48.39%、72.22%和75.92%,仅HIZ组与Modic组、Modic-HIZ组差异有统计学意义(P<0.05);腰痛VAS分别为8.39±0.32分、8.45±0.30分、8.61±0.54分,ODI评分分别为38.22±4.23分、38.45±4.16分、39.18±3.53分,3组间无统计学差异(P>0.05)。结论:腰痛患者下腰椎Modic改变和HIZ的发生率较高,但两者共存于同一节段的发生率低,当两者共存于同一节段时腰痛并不会明显加重。     

基于腰椎间盘退变的脊柱稳定性改变的MRI研究进展

腰椎间盘是位于两个相邻椎体之间的圆盘状纤维软骨,是维持脊柱稳定性的重要解剖结构。目前,维持脊柱稳定性的解剖结构分为被动亚系、主动亚系和神经控制亚系,称为"三亚系模型",腰椎间盘退变(intervertebral disc degeneration,IVDD)会引起该模型其它组织的病理学改变,且彼此相互作用导致脊柱稳定性下降,是下腰痛最常见的原因。IVDD患者常伴有椎小关节及韧带的退变、邻近椎体Modic改变、椎体血流量减少、椎旁肌肉脂肪浸润增加、神经轴向牵拉损伤的代偿性减少等。磁共振成像(magnetic resonance imaging,MRI)是评估脊柱稳定性首选的影像学方法,常规MRI能完整显示IVDD患者三亚系模型相关组织形态学变化,MRI功能成像能定量分析其病理生理学变化的程度。本文综述IVDD患者腰椎间盘、椎小关节、韧带、椎体、肌肉、神经的MRI形态学及定量值变化,阐述IVDD引起脊柱稳定性改变的相关机制,旨在为下腰痛患者的精准诊疗提供更全面的信息。     

The value of SPECT in the detection of stress injury to the pars interarticularis in patients with low back pain

The medical cost associated with back pain in the United States is considerable and growing. Although the differential diagnosis of back pain is broad, epidemiological studies suggest a correlation between adult and adolescent complaints. Injury of the pars interarticularis is one of the most common identifiable causes of ongoing low back pain in adolescent athletes. It constitutes a spectrum of disease ranging from bone stress to spondylolysis and spondylolisthesis. Bone stress may be the earliest sign of disease. Repetitive bone stress causes bone remodeling and may result in spondylolysis, a non-displaced fracture of the pars interarticularis. A fracture of the pars interarticularis may ultimately become unstable leading to spondylolisthesis. Results in the literature support the use of bone scintigraphy to diagnose bone stress in patients with suspected spondylolysis. Single photon emission computed tomography (SPECT) provides more contrast than planar bone scintigraphy, increases the sensitivity and improves anatomic localization of skeletal lesions without exposing the patient to additional radiation. It also provides an opportunity for better correlation with other imaging modalities, when necessary. As such, the addition of SPECT to standard planar bone scintigraphy can result in a more accurate diagnosis and a better chance for efficient patient care. It is our expectation that by improving our ability to correctly diagnose bone stress in patients with suspected injury of the posterior elements, the long-term cost of managing this condition will be lowered.     

The correlation between exaggerated fluid in lumbar facet joints and degenerative spondylolisthesis: prospective study of 52 patients

Background  

Magnetic resonance imaging (MRI) is often used to evaluate low back pain; however, MRI in the supine position does not always reveal degenerative spondylolisthesis. The existence of a linear correlation between increased fluid in the facet joints seen on the supine axial T2 MRI of the lumbosacral spine and lumbar instability seen on standing lateral flexion–extension lumbosacral radiographs has recently been reported. The objective of this prospective study was to determine the incidence of increased fluid in the lumbar facet joints seen on the supine axial T2 MRI, and to evaluate the correlation of this finding with radiographic evidence of lumbar instability.     

Video-assisted ALIF with cage and anterior plate fixation for L5-S1 spondylolisthesis

INTRODUCTION: Spondylolysis and spondylolisthesis grade 0, 1, and 2 are mainly asymptomatic but with aging process and different factors some back pain can occur and lead to chronic low back pain. The conservative treatment with physiotherapy and steroid injection is the gold standard but in some cases is not efficient enough and a surgical treatment is proposed. OBJECTIVES: The goal of this study is to propose a new technique to treat grade 0, 1, and 2 spondylolisthesis with an anterior video-assisted fusion and stabilization. METHODS: Twenty patients with chronic low back pain since more than 2 years and resistant to conservative therapy were included in this protocol. Clinical signs and radicular pain were noted. They were evaluated preoperatively and postoperatively until the last follow up using Oswestry score and visual analog score (VAS) for leg and back pain. X-rays showed grade 0 (8 cases), 1 (10 cases), and 2 (2 cases) spondylolisthesis according to Meyerding classification with disc collapse (bulging disc). MRI showed in all cases a disc degeneration with at least black disc and/or endplates changes with Modic I or II. All patients were operated using an anterior video-assisted retroperitoneal approach, with discectomy and fusion using an anterior impacted cage filled with autologous cancellous bone from the iliac crest and an anterior fixation with a triangular plate (Pyramid, Medtronic, Memphis). The follow up at 3, 6, 12, and 24 months was done with clinical and radiologic evaluation. In case of problem a computed tomography scan was performed. RESULTS: There were 11 women and 9 men, with and average age of 39 years old and a BMI of 25.6. All spondylolistheses occurred at level L5. The average slippage was 19%. All L5S1 discs were black, 8 had a Modic I changes in the endplates and 2 had Modic II. The shape of L5 vertebra was abnormal (trapezoidal) in 7 cases. All anterior approaches were performed without vascular, urologic, or digestive complication. Blood loss was inferior to 100 mL. All patients had a soft brace for 8 weeks postoperatively. There was no retrograde ejaculation for the 9 men and no sexual dysfunction reported by the women. One patient had no pain relief and was reoperated for posterior pedicular screw fixation. It was obvious that there was a pseudarthrosis even after the posterior fixation and an anterior transperitoneal revision was performed with the removal of the interbody device and iliac crest bone graft packing alone. A propioni bacterium acnes germ was found responsible for the anterior nonunion. This revision surgery with antibiotics treatment was successful. One of the patients with grade 2 had an additional posterior screw fixation with a minimally invasive pedicle screw system (Sextant, Medtronic, Memphis). Nineteen patients had a good fusion at 2 years follow-up (95%), mean Oswestry score improved from 74% preoperative to 21% postoperative at the last follow-up. Visual analog score (VAS) for back pain improved from 6.5 to 2.7 and VAS for leg pain improved from 6.2 to 3.4. Satisfaction rate was 90%. All active patients except two, were back to work at an average of 5.5 months (6 wk to 1 y). The 2 patients still not working were the nonunion and a work compensation. CONCLUSIONS: The results of this technique compare favorably with posterior stabilization and fusion (posterior lumbar interbody fusion and postero-lateral fusion) reported in the literature. Unlike posterior lumbar interbody fusion, however, it seems that the complication rate due to the approach is much lower, the fusion rate is similar. Grade 2 SPL is the limitation of the technique. The main advantage of the technique is to avoid posterior muscle damage and a quick recovery with no blood loss. Preservation of adjacent level disease can be assessed only after long-term follow-up.     

Lumbar modic changes-a comparison between findings at low- and high-field magnetic resonance imaging

STUDY DESIGN.: A cross-sectional observational study. OBJECTIVE.: To investigate whether there is a difference in findings of lumbar Modic changes in low-field (0.3 T) magnetic resonance imaging (MRI) compared with high-field (1.5 T). SUMMARY OF BACKGROUND DATA.: It is a challenge to give patients with low back pain a specific diagnosis. Modic changes as seen on MRI have been reported to be a possible source of pain. However, it is unclear whether the diagnosis is independent on the field strength. METHODS.: Twenty patients with Modic changes, 11 women and 9 men (mean age, 53.6 yr; range, 29-81 yr), with or without sciatica, seen in a Danish outpatient low back pain clinic were included. All patients obtained MRI scans on both a high-field and a low-field MRI scanner. Two radiologists evaluated all lumbar endplates independently, using a standardized evaluation protocol. Kappa statistics were used to analyze the interobserver reproducibility. We used paired t test to analyze the difference between low- and high-field MRI. RESULTS.: The total number of Modic changes diagnosed with high-field MRI was significantly higher than that with low-field MRI. However, 3 to 4 times as many Modic type 1 changes were found with low-field MRI compared with high-field MRI. Contrarily, with high-field MRI type 2 changes were diagnosed twice as often. CONCLUSION.: There was a significant difference between low- and high-field MRI regarding the overall prevalence of any Modic change, but this had opposite directions for types 1 and 2: type 2 dominated in low field and conversely in high field. The type of MRI unit should be taken into consideration when diagnosing patients with Modic changes.     

通用型脊柱椎弓根内固定系统治疗腰椎滑脱的临床研究

目的 观察自行研制的通用型脊柱内固定系统用于退行性腰椎滑脱患者手术治疗的疗效。方法 16例退行性腰椎滑脱合并椎管狭窄的患者,均接受了通用型脊柱内固定系统手术治疗。其中男10例,女6例。平均年龄58．5岁(42～72岁)。术前Ⅰ度滑脱10例,Ⅱ度滑脱6例,术后定期随访记录患者的症状改善、滑脱复位程度及并发症等情况。结果 16例患者术后平均随访21．2个月(18～24个月),术后即刻及末次随访时X线摄片显示滑脱腰椎均完全复位,于末次随访时15例患者术前临床症状均消失,滑脱复位满意且无丢失,后外侧植骨融合术后及随访过程中未发现与植入物或手术相关的并发症。结论 初步结果显示,通用型脊柱内固定系统用于腰椎滑脱的手术治疗可获得满意的滑椎复位效果和良好临床疗效。     

Usefulness of single photon emission computed tomography imaging in the detection of lumbar vertebral metastases from prostate cancer

Objective:   To determine whether single photon emission computed tomography (SPECT) is useful in the detection of prostate cancer bone metastases in the lumbar vertebrae.
Methods:   Thirty-nine patients (12 with benign prostatic hyperplasia, 27 with prostate cancer) were considered and submitted to bone SPECT. All of them had increased uptake in lumbar vertebrae on bone scintigraphy. In those with prostate cancer, definitive diagnosis of bone metastases was established by magnetic resonance imaging (MRI). SPECT axial images were classified into five accumulation patterns: mosaic, large hot, diffuse, peripheral, and articular (or pediculate). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of bone SPECT were calculated.
Results:   Overall, 116 vertebral lesions (49 metastatic, 67 degenerative) were studied. Mosaic, large hot and diffuse patterns were more frequently associated with metastatic lesions (84.2%, 70.3%, and 63.1% of the cases, respectively). On the other hand, peripheral and articular (or pediculate) patterns were mostly ascribed to degenerative lesions (100% and 87.5% of the cases, respectively). Sensitivity, specificity, PPV and NPV of bone SPECT were 95.9% (47/49), 73.1% (49/67), 72.3% (47/65), and 96.1% (49/51), respectively.
Conclusions:   Bone SPECT provides better accuracy than bone scintigraphy in differential diagnosis of lumbar vertebral lesions from prostate cancer.