Calcification of the alar ligament of the cervical spine: imaging findings and clinical course

Ligamentous calcification of the cervical spine has been reported in the yellow ligament, anterior and posterior longitudinal ligaments and interspinous ligament. Calcification in the upper cervical spine is rare, although some cases with calcification of the transverse ligament of the atlas have been reported. Two patients with calcification of the alar ligament with an unusual clinical presentation and course are described. Examination by tomography and computed tomography (CT) showed calcification of the alar ligament and the transverse ligament of the atlas. CT documented decreased calcification as symptoms resolved. There may be a role for CT in the search for calcifications in the upper cervical spine in patients presenting with neck pain and pharyngodynia if radiographs are normal. Received: 13 October 2000 Revision requested: 17 November 2000 Revision received: 18 December 2000 Accepted: 19 December 2000     

Neural foraminal ligaments of the lumbar spine: appearance at CT and MR imaging.

Axial and parasagittal computed tomographic (CT) scans and magnetic resonance (MR) images and exactly corresponding sections obtained with the freezing microtome in 18 human cadavers were examined to characterize the radiologic appearance of the lumbar neural forminal ligaments, which have been thought to contribute to nerve root compression. In the CT component of this study, 114 neural foramina at 57 spinal levels were studied; in the MR component, 27 neural foramina were studied. The ligaments originated from the posterolateral margin of the intervertebral disk and attached to the inferior pedicle, superior articular process, transverse process, or ligamentum flavum. On CT scans, they appeared as linear structures with higher attenuation coefficients than those of the adjacent fat and areolar tissue; on MR images, as linear structures with lower signal intensities than those of the adjacent fat and areolar tissue in the neural foramina. It is concluded that the ligaments in the neural foramen can be effectively depicted with CT or MR imaging.     

Interosseous ligament tears of the wrist: comparison of multi-detector row CT arthrography and MR imaging

PURPOSE: To compare the accuracy of multi-detector row computed tomographic (CT) arthrography and magnetic resonance (MR) imaging in depicting tears of dorsal, central, and palmar segments of scapholunate (SL) and lunotriquetral (LT) ligaments in cadavers. MATERIALS AND METHODS: Cadaver wrists were obtained and used according to institutional guidelines and with informed consent of donors prior to death. Nine cadaver wrists of eight subjects were evaluated. MR images were obtained with a 1.5-T MR unit. Imaging protocol included intermediate-weighted coronal and transverse fast spin-echo and coronal three-dimensional gradient-echo sequences. Multi-detector row CT arthrography was performed after tricompartmental injection of 3-6 mL of contrast material with a concentration of 160 mg per milliliter of iodine. Palmar, dorsal, and central segments of both ligaments were analyzed on transverse and coronal MR images and multiplanar multi-detector row CT reconstructions by two musculoskeletal radiologists working independently. Open inspection of the wrists was the reference standard. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated from the imaging and gross pathologic readings. Statistical significance was calculated with the McNemar test. Weighted kappa values for interobserver agreement were calculated for both imaging modalities. RESULTS: All ligament segments could be visualized in all cases with both imaging modalities. CT arthrography was more sensitive (100%) than MR imaging (60%) in detection of palmar segment tears (P = .62); specificity of both imaging modalities was 77%. Sensitivity (CT arthrography, 86%; MR imaging, 79%) and specificity (CT arthrography, 50%; MR imaging, 25%) for detection of the central segment tears were determined. Dorsal segment tears were detected only with CT arthrography, while all tears were missed with MR imaging (P = .02). Interobserver agreement was better for multi-detector row CT arthrography (kappa = 0.37-0.78) than for MR imaging (kappa = -0.33 to -0.10). CONCLUSION: Performance in depiction of palmar and central segment tears of SL and LT ligaments is almost equal for multi-detector row CT arthrography and MR imaging, with much higher interobserver reliability for CT arthrography. CT arthrography is significantly superior to MR imaging in the detection of dorsal segment tears of SL and LT ligaments.     

正常颅颈交界区韧带结构的影像研究

目的 探讨颅颈交界区(CCJ)韧带结构的影像特点,优化该区域韧带的检查方法 及序列.方法 各选取51名健康志愿者,分别行CT和MR检查.分析CCJ韧带结构的CT和MRI表现,并由2名高年资影像医师比较T1WI、T2WI、质子密度加权像(PDWI)、T2*WI、短时反转恢复序列(STIR)及质子密度加权脂肪饱和序列(PDFSAT)对CCJ韧带的显示效果.对原始数据进行标准正态秩变换,然后进行重复测量方差分析.结果 CT和MRI均能清晰显示除寰枕前膜(仅在MRI上显示)以外的CCJ韧带结构及其毗邻结构,其中MRI更具优势.寰枕前膜在MRI上显示率为100%(51/51),齿突尖韧带在CT和MRI上显示率分别为29.4%(15/51)、43.1%(22/51),寰枕后膜-硬膜复合体、覆膜-硬膜复合体、横韧带及翼状韧带在CT和MRI上的显示率均为100%(51/51).2名医师对于PDWI的评分结果 M均为5.0分,差异无统计学意义(F=0.000 P>0.05);PDWI明显高于T1WI(M=3.0分)、T2WI(M=3.0分)、T2*WI(M=1.0分)、STIR(M=1.0分)及PDFSAT(M=3.0分),P值均<0.01.结论 MRI在显示CCJ韧带结构方面优于CT,PDWI为CCJ韧带的最佳MR成像序列.通过对正常CCJ韧带的影像学研究,能够为该区各韧带病变的诊断和治疗提供客观依据.     

Surface coil MR of spinal trauma: preliminary experience

Nineteen fractured vertebral bodies involving the spine from C1 to L2 in 14 patients were imaged with a 0.6-T magnet using prototypical surface coils. Ten of these patients were studied within the first week of trauma. CT and plain films are superior to MR in detecting fractures and identifying the origin of displaced fragments in cases of extensive comminution. However, all body fractures and most posterior element fractures in the thoracolumbar spine were visible on MR. Fractures involving the cervical neural arch were difficult to detect on transverse section without CT correlation. Our results indicate that MR can probably replace CT in the thoracolumbar region. MR is superior to CT in demonstrating ligamentous injury and trauma to the disk. Unlike CT, MR shows the relation of the thecal sac and spinal cord to retropulsed fragments and epidural hematoma. MR also visualizes cord parenchyma; two cases of cord hemorrhage were not seen on CT. Even at this early stage of development, surface coil MR promises to become important in the evaluation of spinal trauma, not only in assessing the integrity of the spinal canal and cord, but in separating stable from unstable fractures on the basis of disruption of the posterior ligaments and elements. Additionally, the demonstration of rupture of specific ligaments may have an impact on surgical management.     

Computed tomography of the cruciate ligaments.

Computed tomography was used to delineate the cruciate ligaments of the knee joint in 31 patients. Optimal positioning for demonstrating the length and body of the anterior and posterior cruciate ligaments is described and the CT, arthrographic, surgical, and clinical findings are correlated. The potential and limitations of CT and its role in combination with double-contrast arthrography in the clinical setting are discussed.     

CT of the normal suspensory ligaments of the ossicles in the middle ear.

PURPOSETo establish the range of normal variation in the CT appearance of the middle ear ligaments and the stapedius tendon as an aid in detecting abnormal changes in these structures.METHODSCT scans of the temporal bone in 75 normal middle ears, obtained with 1-mm-thick sections, were reviewed by two observers, who rated the visibility of the structures of interest on a scale of 1 to 5.RESULTSThe anterior, superior, and lateral malleal ligaments and the medial and lateral parts of the posterior incudal ligament were seen in 68%, 46%, 95%, 26%, and 34% of the ears, respectively. The stapedius tendon was seen in 27% of the cases. When visible, the ligaments were judged to be complete in 90% to 100% of the ears and the stapedius tendon was complete in 65% of cases. Their width varied considerably. Interobserver variability was high for most observations.CONCLUSIONCT scans are more likely to show the malleal than the incudal ligaments. Although the interobserver agreement was statistically significant for most study parameters, the percentage of agreement above that expected by chance was low. When seen, the ligaments usually appeared complete. Understanding the normal range of appearance may help identify abnormalities of the ligaments and tendons of the middle ear.     

MR imaging of normal extrinsic wrist ligaments using thin slices with clinical and surgical correlation

Eighty-nine MR examinations of the wrist were retrospectively analyzed. MRI results were compared with clinical findings and/or arthroscopy. Thin proton density and T2 weighted sequences and 3D DESS weighted sequences were applied on a 1.5 T scanner. On the palmar side three radiocarpal ligaments are recognized including the radioscaphocapitate, radiolunotriquetral, radioscapholunate, and midcarpal triquetroscaphoidal ligaments. Ulnocarpal ligaments include the ulnolunate ligament and the ulnotriquetral ligament. On the dorsal side three ligaments are recognized: the dorsal radiolunotriquetral, and the midcarpal triquetroscaphoidal and triquetro-trapezoido-trapezial. The collateral ligaments include the radial and ulnar collateral ligament. MR is a valuable technique in the assessment of the extrinsic and midcarpal ligaments. Depiction of the extrinsic ligaments can best be accomplished with coronal 3D DESS sequences and sagittal and transverse proton density and T2 weighted sequences with thin slices.     

Computed arthrotomography with multiplanar reformations and three-dimensional image analysis in the evaluation of the cruciate ligaments: preliminary investigation

The normal cruciate ligaments in patient and cadaver knees were imaged with computed tomography (CT) using a graphic system that allowed reformation of the CT data in multiple planes, as well as three-dimensional display. This imaging format afforded excellent visualization of the cruciate ligaments. When the results were correlated with anatomic findings in sections of the knee from cadavers, the image data were found to be accurate.     

Meniscal lesions of the knee joint: CT diagnosis

Computed tomography (CT) resulted in a diagnostic accuracy of 89.2% and 96.1% for medial and lateral meniscal lesions, respectively, in 109 patients who underwent surgery after a direct CT study of the knee joint for a clinically suspected meniscal lesion. The meniscal lesions were the only pathologic condition found in 59 patients, while in 35 patients they were associated with various lesions of the cruciate ligaments (31 cases) and collateral ligaments (15 cases) and with cystic bursitis (6 cases). In the remaining 15 patients, the menisci were normal, but in eight of these cases, lesions of other knee joint structures were present. If meniscal lesions are clinically suspected, direct CT study of the knee joint may be considered the elective radiologic diagnostic method, rather than the more invasive arthrography. It may also be helpful in selecting patients for diagnostic and therapeutic arthroscopy.     

Lateral arcuate ligaments of the diaphragm: anatomic variations at abdominal CT.

The authors have occasionally observed nodular areas abutting the lateral diaphragmatic surface and extending into the posterior pararenal space on computed tomographic (CT) scans. Review of the anatomy literature revealed that this finding represents inferolateral extension of the lateral arcuate ligaments, which reflect over the quadratus lumborum muscles to fuse with the diaphragm. CT scans from 100 consecutive patients were reviewed to determine the frequency, relationship to habitus, and appearance of this finding. Nodularity was found in five patients (bilateral in three, unilateral in two). The average size was 9.4 mm in the transverse plane, 6.3 mm in the anteroposterior plane, and 4.3 cm in the cephalocaudal plane. The extent of retroperitoneal fat was normal in all five patients. In one patient, there were easily visible lobulations; three patients had prominent lobulations, and one patient had few lobulations. It is important to recognize this anatomic variant to avoid confusion with disease.     

Extrinsic carpal ligaments: normal MR arthrographic appearance in cadavers

PURPOSE: To describe the normal magnetic resonance (MR) arthrographic anatomy of the major carpal ligaments (excluding scapholunate and lunotriquetral ligaments) and their osseous attachments by using standard imaging planes. MATERIALS AND METHODS: MR images of 22 wrists derived from fresh human cadaveric hands were obtained after tricompartmental arthrography. The MR arthrographic appearance of the carpal ligaments and their bone attachments were analyzed and correlated to those seen on anatomic sections. Two readers determined in consensus which was the best plane to observe the course and attachment sites for each ligament. They further analyzed the size and sites of attachment of these ligaments in two orthogonal planes chosen for optimal viewing. RESULTS: Each ligament was well seen as a hypointense linear structure with MR arthrography. The radioscaphocapitate, radiolunotriquetral, radioscapholunate, dorsal radiotriquetral, palmar scaphotriquetral, and dorsal scaphotriquetral ligaments were best evaluated in the transverse plane. The palmar and dorsal ulnotriquetral and ulnolunate ligaments were best visualized in the sagittal plane. The radial collateral ligament was best analyzed in the coronal plane. The attachment sites of all ligaments were best analyzed either in the transverse or sagittal planes. CONCLUSION: MR arthrography allows visualization of the carpal ligaments. Detailed knowledge of the normal appearance of these ligaments can serve as a baseline for future studies in which MR arthrography is used to characterize wrist instability.     

MR analysis of the transverse ligament in the late stage of whiplash injury

PURPOSE: To analyse and classify structural changes in the transverse ligament in the late stage of whiplash injury by use of high-resolution MRI, and to evaluate the reliability of our classification. MATERIAL AND METHODS: Ninety-two whiplash-injured (2-9 years previously, mean 6 years) and 30 non-injured individuals underwent proton-weighted MR imaging of the craniovertebral junction in three orthogonal planes. Structural changes in the transverse ligaments were graded twice (grades 1-3) based on increased signal, independently by 3 radiologists with a 4-month interval. Inter- and intraobserver statistics were calculated by ordinary and weighted kappa (K). RESULTS: Image quality was excellent in 109 cases and slightly reduced in 13. Twenty-two out of 30 ligaments in the control group were classified as normal (73%) compared with only 32 out of 92 in the injured group (36%). Two or all 3 observers agreed in their grading in 101 out of 122 ligaments (83%). Intraobserver agreement (weighted K) was fair to good (0.33-0.73). Pair-wise interobserver agreement was fair (0.24-0.39). Reasons for divergent grading were insufficient knowledge of normal variations, low signal intensity in the peridental soft tissue obscuring the ligament and interpretation flaw. CONCLUSION: Whiplash trauma can damage the transverse ligament. By use of high-resolution proton-weighted MR images such lesions can be detected and classified. The reliability of this classification still needs improvement.     

An x-ray computed tomographic study of peritoneal ligaments and various mesos

The CT analysis of peritoneal ligaments and mesos is possible thanks to the fluid contrast introduced by ascites, but also by identification of their contents: fat and opacified vascular elements. Ascites renders easy the display of the falciform ligament. Other displayed ligaments are the smaller omentum, the gastrosplenic ligament, the splenopancreatic ligament, the phrenolienal and phrenocolonic ligaments, the mesocolon, the mesosigmoid, the mesentery and the broad ligaments. The radioanatomic patterns of those peritoneal elements are depicted.     

急性胰腺炎累及横结肠系膜的CT表现与临床严重程度相关性分析

目的探讨急性胰腺炎(AP)中横结肠系膜受累的CT表现分级与临床严重程度的相关性。方法回顾性分析98例AP螺旋CT表现,重点观察横结肠系膜受累的严重程度并进行CT分级,同时记录AP的临床严重程度。结果横结肠系膜的CT表现形态评分与AP的临床严重程度评分呈正相关(r=0.55,P<0.01)。本组轻症AP 64例,其中7例横结肠系膜积液;34例重症AP,20例横结肠系膜积液。若以横结肠系膜积液作为判断重症AP的阳性标准,则其敏感度为60%(20/34),特异度为89%(57/64),阳性预测值为74%(20/27),阴性预测值为80%(57/71),准确度为79%(77/98)。结论横结肠系膜积液的CT表现能在一定程度上反映AP的严重程度。     

MRI of the transverse and alar ligaments in rheumatoid arthritis: feasibility and relations to atlantoaxial subluxation and disease activity

Introduction  

Dysfunctional transverse and alar craniovertebral ligaments can cause instability and osseous destruction in rheumatoid arthritis (RA). This study examined (1) the feasibility of high-resolution magnetic resonance imaging (MRI) of these ligaments in RA and (2) the relation between ligament high-signal changes and atlantoaxial subluxation and RA duration/severity.     

Polygonal deformation of the dural sac in lumbar epidural lipomatosis: anatomic explanation by the presence of meningovertebral ligaments

BACKGROUND AND PURPOSE: In patients with epidural lipomatosis, axial lumbar spine CT and MR images occasionally reveal a geometric, polygonal or stellar, shape of the dural sac. The purpose of this study was to define the anatomic structures responsible for this radiologic appearance. We hypothesized that meningovertebral ligaments could anchor the dura mater to the osteofibrous walls of the spinal canal and account for the geometric deformation of the dural sac. METHODS: The epidural spaces were examined in 15 adult cadaveric and seven aborted fetal lumbar spines. For macroscopic studies, 70 adult vertebral segments were separated and dissected by removing the extradural fat. For microscopic examination, axial histologic sections were obtained from 35 fetal and five adult undissected vertebral segments. RESULTS: Meningovertebral ligaments were observed in the median, paramedian, and lateral aspects of the anterior and posterior epidural spaces of both adult and fetal lumbar spines. These ligaments anchor the outer surface of the dura mater to the osteofibrous walls of the lumbar canal. They may form an irregular longitudinal septum partitioning the epidural space. Histologic examination demonstrated the fibroelastic composition of these ligaments and suggested their possible perivascular morphogenetic origin. CONCLUSION: The morphologic and topographic features of the meningovertebral ligaments explain the polygonal, stellar, or Y-shaped deformation of the dural sac observed on axial CT and MR images in patients with lumbar epidural lipomatosis.     

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.     

Pneumoperitoneum resembling air in the biliary tree: CT features

The various CT appearances of free abdominal air have been described. We present a hitherto undescribed CT manifestation of this condition. When subhepatic free air tracks along the porta hepatis and suspensory ligaments of the liver, it may resemble biliary air.     

Computed tomography of the anterior cruciate ligament

The anterior cruciate ligaments of 20 patients with suspected pathology in one ligament were studied by thin-section computed tomography (CT) and reformating techniques. In 19 patients, the suspect anterior cruciate ligament was abnormal and this was confirmed by subsequent arthroscopy or arthrotomy in thirteen. Thin-section CT and reformatting techniques provide a useful means of non-invasively imaging the anterior cruciate ligament.