A nodular calcification of the alar ligament simulating a fracture in the craniovertebral junction

We report a case of an incidental nodular calcification of the alar ligament simulating a fracture in the craniovertebral junction of a previously healthy 24-year-old man. Three-dimensional CT and MR imaging revealed a 7.2 x 7.6 x 4.0 mm nodular calcification in the right alar ligament with normal adjacent bony structures. Serial cervical dynamic radiographs and open-mouth views showed that the cervical spine was stable without any change in the calcification.     

Helical CT in the primary trauma evaluation of the cervical spine: an evidence-based approach

This review provides a summary of the cost-effectiveness, clinical utility, performance, and interpretation of screening helical cervical spine CT for trauma patients. Recent evidence supports the use of helical CT as a cost-effective method for screening the cervical spine in high-risk trauma patients. Screening cervical spine CT can be performed at the time of head CT to lower the cost of the evaluation, and when all short- and long-term costs are considered, CT may actually save money when compared with traditional radiographic screening. In addition to having higher sensitivity and specificity for cervical spine injury, CT screening also allows more rapid radiological clearance of the cervical spine than radiography. Patients who are involved in high-energy trauma, who sustain head injury, or who have neurological deficits are candidates for CT screening. Screening with CT may enhance detection of other potentially important injuries of the cervical region. Received: 17 March Revision requested: 14 April 2000 Revision received: 19 July 2000 Accepted: 19 July 2000     

The crowned dens syndrome. Evaluation with CT imaging

PURPOSE: The purpose of this study was to verify the value of computed tomography (CT) in the diagnosis of the "crowned dens" syndrome, not only in crystal deposition diseases, but also in other rheumatic or nonrheumatic conditions. MATERIALS AND METHODS: Thirty-eight patients (15 men and 23 women; mean age 55 years; age range 35-79) with neck pain were examined and divided into two groups: (1) patients already identified as rheumatic and referred for further investigation of the atlantoaxial region; (2) patients with symptoms confined to the cervical spine, with inconclusive radiographic findings. Unenhanced CT of the cervical spine (Tomoscan SR 7000 Philips, Eindhoven, Netherlands) was performed in all patients. There were 11 cases of rheumatoid arthritis (ten women and one man), two calcium pyrophosphate dihydrate crystal deposition disease (both women), one of systemic sclerosis (a woman), one of osteoarthritis (a man), one of seronegative arthritis (a man), four of neoplasm (one woman and three men) with suspected cervical involvement, one (a man) of haematological disease (lymphoma), one (a woman) of menopausal osteoporosis, ten (five men and five women) of recent or previous trauma with suspected involvement of the skull base and first cervical vertebrae and six of unknown painful cervical dysfunction (three men and three women). RESULTS: CT demonstrated calcific deposits around the dens in 12 patients (three men and nine women), in the transverse and alar ligaments, and in the anterior atlantooccipital membrane. CT revealed horseshoe- or crown-like calcification surrounding the odontoid process. In our series, other rheumatic diseases, especially rheumatoid arthritis, showed similar irregular calcifications of the atlantoaxial joint. Discussion. In calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, the spine may be the only site of involvement, generally asymptomatic. Crystals located in the transverse ligament of the atlas give rise to the crowned dens syndrome, usually in patients affected by severe degenerative lesions of the atlantoaxial joint and peripheral chondrocalcinosis. Symptoms may be absent, or a neurological compressive syndrome may develop. Symptoms tend to worsen with age. The diagnosis is not always easy, as the symptoms are similar to those of other diseases, such as meningitis, cervicobrachial pain, occipitotemporal headache, calcific tendinitis of the longus colli muscle, spondylodiscitis and retropharyngeal abscess. CONCLUSION: CT is the gold standard in identifying crowned dens syndrome, as it is able to depict the shape and site of calcification and any bone erosions. Radiography of other joints (wrist, knee, pubic symphysis) may help to ascertain whether the disease is due to calcium pyrophosphate dihydrate or hydroxyapatite crystals, and is therefore recommended for routine patient management. Magnetic resonance imaging (MRI) is indicated for the study of neurological complications.     

螺旋CT扫描多平面重建（MPR）诊断颈椎退行性病变

目的 :探讨螺旋CT扫描并多平面重建 (MPR)对颈椎退行性病变的诊断价值。材料和方法 :对 45例颈椎病患者利用常规颈椎CT扫描和螺旋CT扫描并行MPR重建 ,对比分析扫描结果。结果 :螺旋CT扫描并MPR重建除显示 42例表现为一个以上椎间盘突出并压迫神经根及硬脊膜囊外 ,还显示椎体后缘骨质增生 3 0例 ,钩椎关节骨质增生 2 1例 ,2 3例共 2 7个椎间孔狭窄 ,12例共 15个横突孔狭窄 ,9个狭窄横突孔边缘骨质硬化增白 ,并可整体直观的观察韧带骨化、肥厚及椎管狭窄情况。结论 :螺旋CT扫描并MPR重建在显示颈椎退行性变各种病理改变方面比常规CT扫描具有重要的价值。     

Exclusion of unstable cervical spine injury in obtunded patients with blunt trauma: is MR imaging needed when multi-detector row CT findings are normal?

PURPOSE: To retrospectively determine what information, if any, magnetic resonance (MR) imaging of the cervical spine in obtunded and/or "unreliable" patients with blunt trauma adds to multi-detector row computed tomography (CT) of the entire cervical spine (including routine multiplanar sagittal and coronal reformations) when the CT findings are normal. MATERIALS AND METHODS: The study was HIPAA compliant and institutional review board approved. Informed consent was not required. From April 2001 to November 2003, 1400 trauma patients underwent MR imaging of the cervical spine to evaluate potential cervical spine injuries. Multi-detector row CT of the cervical spine was performed with a four- or 16-detector row scanner. MR imaging of the cervical spine was performed with transverse gradient-echo, sagittal intermediate-weighted, sagittal short inversion time inversion-recovery, and sagittal T1- and T2-weighted fast spin-echo sequences. Many MR examinations were performed to exclude soft-tissue injuries in the cervical spine of obtunded patients with blunt trauma in whom cervical spine injury could not be excluded with physical examination. Complete cervical spine MR studies were obtained to evaluate soft-tissue injuries in 366 obtunded patients with blunt trauma (281 male and 85 female patients; age range, 13-92 years; mean age, 42.1 years). The patients had previously undergone total cervical spine multi-detector row CT with normal findings. The results obtained with these two modalities were compared. RESULTS: MR images were negative for acute injury in 354 of the 366 patients and negative for cervical spine ligamentous injury in 362. Seven of the 366 patients had cervical cord contusions, four patients had ligamentous injuries, three patients had intervertebral disk edema, and one patient had a cord contusion, a ligamentous injury, and an intervertebral disk injury. Four patients had ligamentous injuries; however, all of these patients had ligament injuries limited to only one of the three columns of cervical spine ligament support. Multi-detector row CT had negative predictive values of 98.9% (362 of 366 patients) for ligament injury and 100% (366 of 366 patients) for unstable cervical spine injury. CONCLUSION: A normal multi-detector row CT scan of the total cervical spine in obtunded and/or "unreliable" patients with blunt trauma enabled the authors to exclude unstable injuries on the basis of findings at follow-up cervical spine MR imaging.     

寰齿关节退行性变的CT表现及临床分析

目的描述寰齿（ＡＯ）关节退行性变的ＣＴ表现，统计其临床发病率，探讨ＡＯ关节退行性变与临床症状的关系。方法利用薄层ＣＴ扫描对３１７例接受头颅及下位颈椎ＣＴ检查病人的ＡＯ关节进行前瞻性研究。采用双盲法阅片，主要观察内容：骨质增生性改变，关节间隙的改变，横韧带的改变，记录阳性病人的相关临床症状。结果ＡＯ关节退变的ＣＴ表现主要包括：骨赘形成，关节间隙变窄，横韧带钙化及关节内真空现象。４０岁以上的人群中，ＡＯ关节退行性变的发病率随年龄增大逐渐升高（Ｐ＜０．００１）。结论ＡＯ关节退变在中老人中并不少见，ＣＴ可以较好地显示其病理改变     

Delayed diagnosis of isolated alar ligament rupture: A case report

Ligament disruptions at the craniovertebral junction are typically associated with atlantoaxial rotatory dislocation during upper cervical spine injuries and require external orthoses or surgical stabilization. Only in few patients isolated ruptures of the alar ligament have been reported. Here we present a further case, in which the diagnosis was initially obscured by a misleading clinical symptomatology but finally established six month following the trauma, demonstrating the value of contrast-enhanced high resolution 3 Tesla magnetic resonance imaging in identifying this particular lesion.     

MRI of cervical spine injuries complicating ankylosing spondylitis

OBJECTIVE: The objective was to study characteristic MRI findings in cervical spine fractures complicating ankylosing spondylitis (AS). Technical issues related to MRI are also addressed. MATERIALS AND METHODS: A review of 6,774 consecutive cervical spine multidetector CT (MDCT) scans obtained during 6.2 years revealed 33 ankylosed spines studied for suspected acute cervical spine injury complicating AS. Of these, 20 patients also underwent MRI. RESULTS: On MRI, of these 20 patients, 19 had a total of 29 cervical and upper thoracic spine fractures. Of 20 transverse fractures traversing both anterior and posterior columns, 7 were transdiskal and exhibited less bone marrow edema than did those traversing vertebral bodies. One Jefferson's, 1 atlas posterior arch (Jefferson's on MDCT), 2 odontoid process, and 5 non-contiguous spinous process fractures were detectable. MRI showed 2 fractures that were undetected by MDCT, and conversely, MDCT detected 6 fractures not seen on MRI; 16 patients had spinal cord findings ranging from impingement and contusion to complete transection. CONCLUSION: Magnetic resonance imaging can visualize unstable fractures of the cervical and upper thoracic spine. Paravertebral hemorrhages and any ligamentous injuries should alert radiologists to seek transverse fractures. Multiple fractures are common and often complicated by spinal cord injuries. Diagnostic images can be obtained with a flexible multipurpose coil if the use of standard spine array coil is impossible due to a rigid collar or excessive kyphosis.     

翼状韧带的影像解剖学研究

目的探讨翼状韧带的位置、形态及走行，并深入研究其断面解剖形态及CT和MRI表现。方法采用经福尔马林固定的正常成人头颅标本12例，其中3例用于大体解剖观察，3例制成5．0mm厚的冰冻切片，6例制成0．5mm厚的薄层切片；选取2组各51例健康志愿者分别行CT和MRI检查。结合大体和断面解剖，分析翼状韧带的CT和MRI表现，并对其进行影像学测量。结果大体和断层解剖均能清晰显示翼状韧带的位置、形态及走行。齿状突上部的横断面和齿状突中部的冠状面是显示翼状韧带的理想层面。翼状韧带在CT和MRI横断面、冠状面及矢状面上的显示率均为100％（51／51）。对于翼状韧带结构的显示，MRI优于CT，尤其是质子密度加权成像的显示效果最佳。翼状韧带宽度在男女性别及左右侧别间的差异无统计学意义（P〉0．05）。结论CT和MRI均能较好地显示翼状韧带，结合大体和断层解剖进行研究，可为翼状韧带创伤、畸形及感染等病变的诊断提供影像解剖学支持。     

Ultrasound-guided aspiration of posterior cruciate ligament ganglion cysts

Intra-articular ganglion cysts of the knee joint are rare. Percutaneous aspiration of ganglion cysts of the knee, which has both diagnostic and therapeutic value, has been described, but usually under guidance by computed tomography (CT). We describe ultrasound-guided aspiration of posterior cruciate ligament cysts in two patients. Received: 20 November 2000 Revision requested: 23 January 2001 Revision received: 13 March 2001 Accepted: 15 March 2001     

Ossification of the ligamentum flavum associated with osteoblastoma: a report of three cases

We report three cases of spinal osteoblastoma with ossification of the ligamentum flavum (OLF) adjacent to the tumor. The patients in this report, all young adults, had no symptoms except for back pain. Computed tomography (CT) demonstrated a typical radiolucent nidus in the spinal pedicle/lamina with a dense sclerotic rim. In addition, ectopic bone formation at the insertion point of the ligamentum flavum adjacent to the tumor was clearly illustrated. Magnetic resonance imaging (MRI) revealed the tumor and surrounding inflammatory responses, but OLF was not detected clearly. Histological examination revealed endochondral ossification of the ligamentum flavum that is quite unusual for normal young adults. Immunohistochemical assays in one case demonstrated that bone morphogenetic protein (BMP)-2/4 was expressed in the osteoblastic tumor cells. This case raises the possibility that BMPs secreted from the tumor cells triggered ectopic ossification in the spinal ligament. Received: 7 August 2000 Revision requested: 15 November 2000 Revision received: 15 December 2000 Accepted: 19 December 2000     

Cervical spine injury in the elderly: imaging features

An increase in the elderly population has resulted in an increased incidence of cervical spine injury in this group. No specific type of cervical spine trauma is seen in the elderly, although dens fractures are reported to be common. Hyperextension injuries due to falling and the resultant central cord syndrome in the mid and lower cervical segments due to decreased elasticity as a result of spondylosis may be also characteristic. The imaging features of cervical spine injury are often modified by associated spondylosis deformans, DISH and other systemic disorders. The value of MR imaging in such cases is emphasized. Received: 14 April 2000 Revision requested: 30 June 2000 Revision received: 18 August 2000 Accepted: 4 October 2000     

Computed tomography of the upper cervical spine in Down syndrome

Axial CT of the upper cervical spine was performed on 25 Down syndrome patients. Measurements of the degree of atlantoaxial displacement, the sagittal diameters of the spinal canal and spinal cord, thickness of the transverse ligament, and the ratio of sagittal diameter of spinal cord to canal were made. Thirty-six percent of the group showed evidence of cord compression. These patients demonstrated a significant decrease in the anteroposterior diameter of the spinal canal and the cord with an increase in the degree of subluxation and the cord:canal ratio when compared with the remainder.     

Functional diagnostics of the cervical spine using computer tomography

Summary 35 healthy adults and 137 patients after cervical spine injury were examined by functional CT. The range of axial rotation at the level occiput/atlas, atlas/axis and the segment below were measured in all subjects. A rotation occiput/atlas of more than 7°, and C1/C2 more than 54° could indicate segmental hypermobility, a rotation at the segment C1/C2 less than 29° to hypomobility. According to the postulated normal values based upon a 98% confidence level, out of 137 patinets examined after cervical spine injury and with therapyresistant neck pain, 45 showed signs of segmental hypermobility of the upper cervical spine, 17 showed hyper- or hypomobility at different levels, 10 patients presented segmental hypomobility at C1/C2 level alone. In all patients, according to the clinical assessment, functional pathology was suspected in the upper cervical spine. Surgical correction of rotatory instability should be considered as a possible therapeutic procedure after successful diagnostic stabilisation of the cervical spine by minerva cast.Paper presented at the Meeting of the Cervical Spine Research Society, June 21–24, 1987, Pavia, Italy     

Calcium pyrophosphate dihydrate crystal deposition in and around the atlantoaxial joint: association with type 2 odontoid fractures in nine patients

PURPOSE: To investigate the histopathologic anatomy of calcium pyrophosphate dihydrate (CPPD) crystal deposition in and around the atlantoaxial joint and the association between CPPD crystal deposition and subchondral cysts, erosions, and fracture involving the odontoid process of the axis. MATERIALS AND METHODS: One adult cadaver demonstrating calcification in the retro-odontoid area at computed tomography (CT) was selected for further radiography, CT, and magnetic resonance (MR) imaging at the C1-2 level. Anatomic sectioning and histologic evaluations were performed in the specimen. For clinical study, radiographs (n = 5), CT scans (n = 8), and MR images (n = 6) in nine patients (mean age, 74.4 years) with odontoid process fractures and CPPD crystal deposits in and around the atlantoaxial joint were reviewed. RESULTS: In the cadaveric specimen, radiography and CT demonstrated calcifications in the transverse ligament; histologic evaluation confirmed that these calcifications were CPPD crystal deposits. In all nine patients, radiography (n = 5) and CT (n = 8) also showed calcification in areas adjacent to the odontoid process, which included the transverse ligament. T1- and T2-weighted MR imaging showed a retro-odontoid mass of low signal intensity that compressed the cervical cord in six patients. CT, MR imaging, or both demonstrated subchondral cysts, osseous erosions, or a type 2 odontoid fracture in all patients. CONCLUSION: CPPD crystal deposition disease involving the C1-C2 articulation can be a clinically important entity that may place affected patients at increased risk of pathologic fracture of the odontoid process.     

Association of diffuse idiopathic skeletal hyperostosis (DISH) and calcification and ossification of the posterior longitudinal ligament.

Diffuse idiopathic skeletal hyperostosis (DISH) is a common ossifying diathesis in middle-aged and elderly patients characterized by bone proliferation along the anterior aspect of the spine and at extraspinal sites of ligament and tendon attachment to bone. Four patients with DISH revealed extensive calcification and ossification of the posterior longitudinal ligament in the cervical spine. Review of cervical spine radiographs in 74 additional patients with DISH demonstrated bony hyperostosis of the posterior aspect of the vertebrae in 41%, posterior spinal osteophytosis in 34%, and posterior longitudinal ligament calcification and ossification in 50%. These ligamentous findings, which have previously been described almost exclusively in Japanese people, appear to be an additional skeletal manifestation of DISH.     

Put your back into it: pathologic conditions of the spine at chest CT

It is common to encounter pathologic processes of the lower cervical, thoracic, or upper lumbar spine in the course of routine computed tomography (CT) of the chest. Although magnetic resonance (MR) is the imaging modality of choice for evaluating known spinal disease, evaluation of the spine is an integral part of interpreting a chest CT study. Spinal diseases often have a characteristic CT appearance that allows the radiologist to make the diagnosis or provide a structured differential diagnosis. Pathologic conditions of the spine that can be identified at chest CT are categorized into benign or incidental findings, congenital anomalies, traumatic injuries, infectious spondylitis, primary or secondary neoplastic involvement, and associations with systemic disease. CT also provides information about bone mineralization and lesion calcification that complements the superior soft-tissue imaging capability of MR. In addition, chest CT data may be reformatted to create volumetric or multiplanar images of the spine to facilitate management decisions about spinal stabilization in symptomatic patients.     

Unstable Jefferson variant atlas fractures: an unrecognized cervical injury.

We retrospectively reviewed the plain films and CT scans of 11 unstable atlas fractures from a series of 72 atlas fractures to better characterize these injuries and to determine if the correct diagnosis could have been made. These 11 atlas fractures were unstable because either the anterior bony ring was disrupted (six cases), the posterior longitudinal ligament was torn (one case), or both the anterior bony ring and the posterior longitudinal ligament were disrupted (four cases), allowing C1-C2 subluxation to occur. Although all the fractures were potentially unstable, only eight demonstrated subluxation on the lateral radiography. Despite the abnormal open mouth view in all cases, the plain films showed minimal abnormalities, requiring CT for definitive diagnosis. Less than half (five of 11) of the patients had other levels of spine injury or associated transverse ligament tear. Three of the 11 patients were quadriplegic, and two died as a result of their spinal cord injury. These unstable atlas fractures were similar to the classical Jefferson fracture in appearance and mechanism, except that they had fewer than four breaks in the atlas ring and were associated with severe neurologic injury and lower level spine injuries. The pattern of bilateral anterior arch fractures was associated more often with neurologic injury. Because of these differences, we chose to refer to them as Jefferson variant fractures to distinguish them from the classical Jefferson fracture and to emphasize the seriousness of this injury.     

螺旋CT三维重建对颈椎狭窄症的术前评价

目的探讨螺旋CT三维重建对颈椎狭窄症术前的诊断价值。方法用螺旋CT对45例拟行手术治疗的颈椎狭窄症患者行薄层容积扫描,采用合适的重建参数及阈值在工作站上进行三维重建,多角度、多层面拍片。结果三维重建图像清晰显示颈椎椎管、横突孔及椎间孔的狭窄情况,45例患者中,其CT表现有椎体骨质增生(n=36),骨质增生合并后纵韧带肥厚骨化(n=6),椎问盘钙化(n=3),横突孔狭窄(n=9)以及椎间孔不规则狭窄(n=24)。上述CT诊断均经病理证实。结论螺旋CT三维重建简化了观察者的思维过程,可直观地了解颈椎狭窄症的三孔立体空间的实际大小、形态、位置及周围组织的立体解剖显示,可为制订手术方案提供重要的信息。     

Computed tomography of the craniocervical junction in rheumatoid arthritis

Thirty-three patients with rheumatoid arthritis had computed tomographic examination of the craniocervical junction. This demonstrated soft tissue features which have not previously been described in published reports. A low attenuation lesion between the odontoid and the transverse ligament shown in 11 patients was considered a premonitory sign of rupture of the transverse ligament or a manifestation of active disease. Computed tomography revealed spinal cord compression in 3 patients and ligamentous changes in the transverse ligament and the alar and spinal ligaments in 26 patients. Erosion of the odontoid was shown in 19 patients and subluxation in 20 patients. No relationship could be found between the clinical signs and symptoms and the radiological abnormalities except in the case of cord compression.