Infection versus neoplasm in the spine: differentiation by MRI and diagnostic pitfalls

MRI images of 135 patients with spine infection and 81 patients with spine neoplasm were retrospectively analysed in order to identify criteria that will help in distinguishing infection from neoplasm and in differentiating the forms of spine infection. Disc involvement occurred in 93% of infections and only 1% of neoplasms. Features of tuberculous spondylitis included paraspinal soft tissue abscesses (95%), vertebral collapse (91%), pathognomonic intraosseous abscess seen on Gd-enhanced images (84%), epidural extension (68%), gibbus (26%), skip lesions (16%) and posterior element involvement (11%). Pyogenic and brucellar infections had comparable features, i. e. predilection for the lower lumbar spine, preservation of vertebral morphology, minimal granulation tissue production and epidural extension. Primary neoplasms affected solitary vertebrate while secondary neoplasms demonstrated skip lesions and frequent extraosseous soft tissue masses. Posterior elements were frequently affected in both. MRI is a useful method for distinguishing infection from neoplasm in the spine and for differentiating tuberculous spondylitis from other infections in the majority of cases. Correspondence to: M. C. Haddad     

Synovial cysts of the lumbar spine: CT and MRI correlations

Intraspinal synovial cysts were diagnosed in six patients during a 5-year period and retrospectively studied. Plain films of the lumbar spine showed degenerative changes in all patients. Lumbar myelography showed a posterior and lateral defect caused by extradural compression. Using CT without constrast enhancement established the diagnosis in five of the six-patients. in four cases MRI was performed, three before and after injection of gadolinium diethyline-triamine penta-acetic acid )Gd-DTPA). Including the patient with a false negative CT, MRI was positive in all patients.     

儿童脊柱正常MRI与胎儿脊柱骨发育

目的 :探讨胎儿椎体和椎间盘的组织学结构以及儿童脊柱的正常X线和MRI表现。方法 :44周胎儿X线平片 1例 ;儿童脊柱正常椎体MRI 13例 ;胎儿脊柱标本 2 6例 ,全部标本经固定、水冲洗、分批脱水、火棉胶包埋后制成脊柱标本整体切片 ,HE染色。结果 :44周胎儿脊柱每个椎体前面X线表现均有“V”字形凹陷。 13例儿童脊柱正常椎体MRI ,共分析了110个椎体的信号变化 ,其T1WI和T2 WI表现 :44 %的椎体前面“V”形凹陷呈高信号 ,63 %的椎体后面“V”形凹陷 ;16.4%的椎体前后面均凹陷 ;47%的椎体中心有雪花样高信号 ;13例中有 9例各椎体内均有双层低信号生长线。 2 6例胎儿脊柱椎体的组织学结构 :① 12周和 15周胎儿 ,椎体软骨内血管数量较多 ;②胎儿椎体前、后面中部凹陷 ,以膜内成骨形成“V”字形骨皮 ,不同病例椎体前面或后面均可见凹陷 ,出现率 9.6%～ 2 7.1% ,有 2例在椎体前面“V”字骨皮内形成松质骨小梁 ,并有骨髓形成 ;③椎体骨化中心有红髓和血管 :椎体后面“V”字骨皮内的大静脉窦与骨化中心静脉窦相通 ;④椎间盘 :只见于 12周的胎儿椎间盘内有血管 ,2例紧贴椎间盘的软骨椎体内见无细胞区 ,且部分髓核物突入椎体软骨内。结论 :4～ 11岁儿童脊柱正常椎体MRI表现仍然相应的保持着胎儿脊柱骨发育的组织学特点     

MR imaging of the cervical spine: assessment of image quality with parallel imaging compared to non-accelerated MR measurements

To compare the quality of cervical spine MR images obtained by parallel imaging [generalized autocalibrating partially parallel acquisition (GRAPPA)] with those of non-accelerated imaging, we conducted both phantom studies and examinations of ten volunteers at 1.5Tesla with a dedicated 12-element coil system and a head-spine-neck coil combination. Acquisitions included axial T2-weighted (T2w) images with both methods, and sagittal T2w and T1w images in vivo with the latter coil combination. Non-accelerated MRI with two averages and GRAPPA (acceleration factor 2) with two averages (GRAPPA/2AV, time reduction of approximately 50%) and four averages (GRAPPA/4AV) were compared. In the phantom, the signal-to-noise ratio of the GRAPPA/2AV was lower than that of the other two settings. In vivo, the image inhomogeneity (non-uniformity, NU) was significantly higher in T2w GRAPPA/2AV than in both other settings, and in T1w GRAPPA/2AV compared to GRAPPA/4AV. Subjectively, the delineation of anatomical structures was sufficient in all sequences. Only the spinal cord was considered to be better delineable on the non-accelerated T1w sequence compared to GRAPPA/2AV. In part, GRAPPA/4AV performed better than the other settings. The subjective image noise was lowest with GRAPPA/4AV. In cervical spine MRI, the examination time can be reduced by nearly 42% with GRAPPA, while preserving sufficient image quality.     

MR imaging of the neural foramina of the cervical spine. Comparison of 3D-DESS and 3D-FISP sequences

Purpose: To assess whether a single three-dimensional double-echo steady state (3D-DESS) sequence can produce equivalent results when compared to a 3D free induction with steady precession (3D-FISP) sequence for the evaluation of the neural foraminal diameter and structures.Material and Methods: Five phantoms were imaged on CT with 3-mm axial slices followed by reformatted axial 3D-DESS and 3D-FISP sequences. In addition, 3D-DESS and 3D-FISP sequences of 20 healthy subjects were compared with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural foramina, and differentiation between vertebrae and neural foramina.Results: Compared with CT, 3D-DESS and 3D-FISP sequences consistently underestimated the diameters of the neural foramina. The mean difference values for the 3D-DESS was 12.8%, compared to 9.5% for the 3D-FISP sequence. Concerning the in vivo studies, the 3D-DESS sequence was superior but not statistical significant to the 3D-FISP sequence with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural formina, and identification of the nerve roots.Conclusion: The 3D-DESS sequence is moderately accurate in the evaluation of the neural foraminal size. Compared to the 3D-FISP sequence, the 3D-DESS sequence is compatible concerning the image quality, differentiation between the cervical vertebrae and discs, and between the discs and neural foramina.     

Fibrogenesis imperfecta ossium: MR imaging of the axial and appendicular skeleton and correlation with a unique radiographic appearance

We describe a distinctly unusual MR appearance of the cancellous bone never before described in a patient with biopsy-proven fibrogenesis imperfecta ossium.     

Longitudinal study of vertebral type-1 end-plate changes on MR of the lumbar spine

The purpose of this study was to investigate the temporal evolution of type-1 end-plate changes on MRI in patients with degenerative disease of the lumbar spine and to evaluate whether any correlation exists between such evolution and the change in patients symptoms. Forty-four patients with 48 Modic type-1 end-plate changes (low TI signal and high T2 signal) were studied. All patients had an initial and a follow-up non-contrast lumbar MRI with variable intervals between the studies (12–72 months). Severity of the end-plate changes was assessed by eyeball estimation. Correlation with patients symptoms was studied with the help of the Visual Analogue Score (VAS), Oswestry Questionnaire Score (OQS) and patients subjective assessment. Of the 48 disc levels with type-1 changes, 18 (37.5%) converted fully to type 2 (high T1 signal and intermediate to high T2 signal), 7 (14.6%) partially converted to type 2, 19 (39.6%) became worse (i.e. type 1 changes became more extensive) and 4 (8.3%) showed no change. Higher average VAS (5.7) and OQS (42.3) scores were noted in patients where there was worsening type-1 change and lower scores (3.8 and 27, respectively) were seen in those where there was conversion to type-2 change. These trends, however, did not reach statistical significance (P values 0.16 and 0.09 for VAS and OQS, respectively). The statistical relationship was stronger after exclusion of patients with confounding factors (i.e. changes in lumbar MRI other than end-plate changes that could independently explain the evolution of patients symptoms) with P-values of 0.08 and 0.07 for VAS and OQS, respectively. Type-1 end-plate change represents a dynamic process and in a large majority of cases either converts to type-2 change or becomes more extensive. The evolution of type-1 change relates to change in patients symptoms, but not to a statistically significant level.     

MR imaging in the evaluation of trauma

Although computed tomography (CT) and radiographs are primary modalities in the evaluation of patients undergoing trauma, the indications for magnetic resonance (MR) imaging in trauma have grown. MR has been most useful in patients with central nervous system or musculoskeletal trauma. In head trauma, MRI is most useful in the evaluation of patients with neurologic deficit greater than that expected from CT findings. MRI is useful in such situations because of its improved sensitivity to nonhemorrhagic and microhemorrhagic lesions as well as posterior fossa pathology. In the spine, MRI provides detailed assessment of the disc space, spinal cord, and ligamentous structures; guiding therapeutic decisions; and offering prognostic information. In the musculoskeletal system, MRI offers a noninvasive means of imaging injuries to the muscles, tendons, ligaments, and cartilage of the knee, shoulder, ankle, and elbow. Additionally, MRI may define a subset of radiographically occult bony injuries.     

Surgically induced intracranial contrast enhancement: potential source of diagnostic error in intraoperative MR imaging.

BACKGROUND AND PURPOSE: Intraoperative MR imaging is being used increasingly during neurosurgical interventions. The aim of this study was to describe and classify different forms of surgically induced intracranial contrast enhancement observed during intraoperative MR examinations. METHODS: A total of 51 intraoperative MR examinations were performed to assess the extent of brain tumor removal. The intraoperative MR results (T1-weighted images, unenhanced and obtained serially after the IV administration of paramagnetic contrast material) were compared with preoperative and early postoperative MR findings. Animal experiments were conducted to obtain further evidence of the mechanism of surgically induced contrast enhancement. RESULTS: Four different types of surgically induced contrast enhancement were found: meningeal enhancement, increased enhancement of the choroid plexus, delayed enhancement at the resection margins, and immediate intraparenchymal contrast enhancement. The types of surgically induced contrast enhancement differ regarding their location, configuration, and time course. Their potential to be confused with contrast-enhancing, residual tumor also varies. Three of the four types of surgically induced contrast enhancement were reproducible in an animal model. CONCLUSION: Surgically induced contrast enhancement is a potential source of error in intraoperative MR imaging. Careful analysis of the location, configuration, and time course of intraoperatively observed intracranial enhancement is critical to avoid confusing surgically induced contrast enhancement with contrast-enhancing, residual tumor.     

Evaluation of the cervical spine in the obtunded patient

Assessment of cervical spine stability in the posttraumatic obtunded patient can be difficult to accomplish with currently available imaging modalities. Dynamic fluoroscopy during passive flexion and extension has been proposed by some authors as a method for the evaluation of cervical spine stability. We present our experience with dynamic fluoroscopy, the general opinions of multiple trauma centers, and alternative methods for evaluating cervical spine stability in the obtunded patient. The potential risks and problems associated with each method are discussed.     

脊椎骨巨细胞瘤的MRI表现：附7例报告

本文分析了７例脊柱骨巨细胞瘤的ＭＲＩ表现，ＭＲＩ能清楚地显示肿瘤的边缘及其对周围组织的压迫和侵犯，但定性诊断仍缺少特征性诊断依据。     

Whole-body imaging of the musculoskeletal system: the value of MR imaging

In clinical practice various modalities are used for whole-body imaging of the musculoskeletal system, including radiography, bone scintigraphy, computed tomography, magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT). Multislice CT is far more sensitive than radiographs in the assessment of trabecular and cortical bone destruction and allows for evaluation of fracture risk. The introduction of combined PET-CT scanners has markedly increased diagnostic accuracy for the detection of skeletal metastases compared with PET alone. The unique soft-tissue contrast of MRI enables for precise assessment of bone marrow infiltration and adjacent soft tissue structures so that alterations within the bone marrow may be detected before osseous destruction becomes apparent in CT or metabolic changes occur on bone scintigraphy or PET scan. Improvements in hard- and software, including parallel image acquisition acceleration, have made high resolution whole-body MRI clinically feasible. Whole-body MRI has successfully been applied for bone marrow screening of metastasis and systemic primary bone malignancies, like multiple myeloma. Furthermore, it has recently been proposed for the assessment of systemic bone diseases predisposing for malignancy (e.g., multiple cartilaginous exostoses) and muscle disease (e.g., muscle dystrophy). The following article gives an overview on state-of-the-art whole-body imaging of the musculoskeletal system and highlights present and potential future applications, especially in the field of whole-body MRI.     

A case of ochronosis: MRI of the lumbar spine

We present the MRI features of the lumbar spine in a patient with ochronosis. Received: 25 October 1999/Accepted: 8 April 2000     

Refinements of the anteroposterior angled caudad view of the lumbar spine

In a previous article describing the anteroposterior angled caudad view the authors described a technique to more clearly evaluate the posterior elements of the lumbosacral spine, especially the articular facets, using standard radiographic techniques. This article details the specific pathology which can be evaluated. Multiple cases and examples of the view are given and comments regarding calcifications of the capsule of the articular facets and findings in trauma and post-surgical changes are described.     

放疗后脊柱MRI表现

探讨放疗后脊柱骨髓ＭＲＩ的特征。材料与方法；本组５５例脊柱放疗后患者，放疗剂量２１００－７５００ｃＧｙ，各病例开始放疗后ＭＲ检查之间的间隔时间不等，最短的是７周，最长的是２０年。结果：ＭＲＩ表现为：Ｔ１ＷＩ像椎体呈明显高信号改变，且信号均匀，与非照射野的脊柱分界清晰；Ｇ２ＷＩ像呈均匀的稍高信号；ＳＴＩＲ或Ｔ１ＷＩ抑脂成像显示椎体呈明显低信号改变。     

Candida osteomyelitis and disc space infection of the lumbar spine

 Candida osteomyelitis is an uncommon complication of immunosuppressive therapy. Its radiographic manifestations are similar to those of other relatively indolent infectious agents. We report the CT and MR findings in a patient who developed this condition following treatment for acute myelogenous leukemia, and review the imaging literature covering similar cases.     

腰椎轴向负荷的CT、MR检查对腰椎退行性病变的诊断价值

目的：评价腰椎轴向负荷的CT、MR检查对腰椎退行性病变的诊断价值。方法：对100例腰腿痛的患者（79例表现为坐骨神经痛，20例为下腰痛，1例为神经性跛行）分别行腰大肌放松体位（PRP）和腰椎轴向负荷仰卧位（ACE）的CT或MR检查。其中CT检查40例，MR检查60例。硬膜囊面积在ACE检查中较PRP明显减小（〉15mm^2）并降到75mm^2以下、侧隐窝和（或）椎间孔狭窄、椎间盘突出程度增加及出现滑膜囊肿为腰椎轴向负荷检查的附加信息（AVI）。结果：40例CT检查的患者中，16例发现AVI。其中硬膜囊面积减小13例，椎间盘突出程度增加7例，侧隐窝和（或）椎间孔狭窄4例，未见滑膜囊肿的病例。60例MR检查的患者中，19例发现AVI，其中硬膜囊面积减小13例，椎间盘突出程度增加10例，侧隐窝和（或）椎间孔狭窄8例，未见出现滑膜囊肿的病例。79例坐骨神经痛的患者中32例（40．5％）出现AVI，20例下腰痛的患者中2例（10．0％）出现AVI（X2=7．45，P〈0．05）。结论：与常规腰椎CT、MR方法比较，腰椎轴向负荷的CT、MR检查更能反映腰椎直立状态下的椎间盘、硬膜囊、侧隐窝的状态。     

Epidural fat interposition between dura mater and spinous process: a new sign for the diagnosis of spondylolysis on MR imaging of the lumbar spine

The purpose of this study was to assess the diagnostic value of epidural fat interposition between the dura mater and spinous process of L5 as an indirect sign of spondylolysis on mid-sagittal MR imaging of the lumbar spine. Mid-sagittal T1-weighted MR images of the lumbar spine of 85 patients with spondylolysis and 93 patients without pars interarticularis fractures were randomized and evaluated by a masked reader. After a training sample of five cases, the reader was asked to note the presence or absence of epidural fat interposition between the dura mater and spinous process of L5 on the randomized images. The epidural fat interposition between the dura mater and spinous process of L5 was noted in 67 out of the 85 patients with spondylolysis (78.8%) and three of the patients without pars interarticularis fracture (3.2%). The difference was statistically significant (P<0.01). This sign has a specificity of 96.7%, sensitivity of 78.8%, positive predictive value of 95.7%, negative predictive value of 83.3% and accuracy of 88.2% for diagnosis of spondylolysis. Epidural fat interposition between the dura mater and spinous process may be a helpful sign for the diagnosis of spondylolysis on mid-sagittal MR imaging of the lumbar spine.     

Segmental enhancement on breast MR images: differential diagnosis and diagnostic strategy

The histopathological variations of segmental enhancement on breast magnetic resonance imaging (MRI) were investigated, with the aim of identifying imaging characteristic clues to their differential diagnosis. We reviewed 70 breast MRI examinations demonstrating segmental enhancement, classified them based on their histopathology, and assessed their MRI findings as follows: (1) confluent or not confluent, (2) late enhancement pattern, and the absence or presence of (3) clustered ring enhancements and (4) surrounding high signal intensity (SI) on T2-weighted imaging. Thirteen lesions (18.5%) were benign, eight (11.5%) were high risk, 25 (36%) were ductal carcinoma in situ (DCIS) and 24 (34%) were infiltrating mammary carcinomas (IMC). Clustered ring enhancements were demonstrated in 74% of malignancies (high risk, DCIS and IMC) but no benign lesions (P = 0.0001). The surrounding high SI on T2-weighted imaging was seen in four of five IMC with marked lymphatic involvement. Clustered ring enhancement was not demonstrated in six of seven IMC of tubular and/or lobular types. Segmental enhancement was seen in not only DCIS but also IMC, high-risk and benign lesions. Clustered ring enhancement and surrounding high SI on T2-weighted imaging were clues to their differential diagnosis and helpful to decide their diagnostic strategy.     

Anomalies of the long head of the biceps brachii tendon: clinical significance,MR arthrographic findings,and arthroscopic correlation in two patients

Two patients with clinically relevant anomalies of the long head of the biceps brachii tendon (LHBT) are presented with MR arthrography and surgical correlation. Such variations in the LHBT can mimic tears of the tendon itself or the adjacent superior labrum both on MR arthrography and at surgery. MR arthrographic features are recognizable and allow for correct prospective diagnosis, possibly averting unnecessary surgery. Although further study is needed, patients with these anomalies may be at increased risk for developing shoulder instability.