Cartilage assessment of the metacarpophalangeal joints: cadaveric study with magnetic resonance arthrography and finger traction

We investigated the efficacy of axial traction of the fingers combined with magnetic resonance (MR) arthrography in assessing the metacarpophalangeal (MCP) joint cartilage in cadavers. Cartilage was imaged and graded before/after MR arthrography, with/without traction, then correlated with cadaveric sectioning. The application of traction with MR arthrography is a promising technique for improved visualization of the articular cartilage of the MCP joints compared with similar imaging without traction and/or without arthrography, but its true benefit requires further study.     

MRI of the cartilage

With the introduction of fat-suppressed gradient-echo and fast spin-echo (FSE) sequences in clinical routine MR visualization of the hyaline articular cartilage is routinely possible in the larger joints. While 3D gradient-echo with fat suppression allows exact depiction of the thickness and surface of cartilage, FSE outlines the normal and abnormal internal structures of the hyaline cartilage; therefore, both sequences seem to be necessary in a standard MRI protocol for cartilage visualization. In diagnostically ambiguous cases, in which important therapeutic decisions are required, direct MR arthrography is the established imaging standard as an add-on procedure. Despite the social impact and prevalence, until recent years there was a paucity of knowledge about the pathogenesis of cartilage damage. With the introduction of high-resolution MRI with powerful surface coils and fat-suppression techniques, visualization of the articular cartilage is now routinely possible in many joints. After a short summary of the anatomy and physiology of the hyaline cartilage, the different MR imaging methods are discussed and recommended standards are suggested. Electronic Publication     

MR Arthrography of the Hip

Magnetic resonance imaging (MRI) of the hip has been valuable in the diagnosis of occult osseous abnormalities and of periarticular soft tissue disorders. MRI has been less useful in the evaluation of acetabular labral tears and other intra-articular abnormalities. Image optimization is more technically challenging in the hip than in smaller joints because the overlying soft tissues are thicker, resulting in decreased spatial and contrast resolutions that may not be adequate to distinguish the acetabular labrum from subchondral bone, articular cartilage, and joint capsule. MR arthrography (MRA) extends the capabilities of conventional MRI because contrast solution separates intra-articular structures and outlines abnormalities. In hips with suspected acetabular labral injury, arthrographic MR images demonstrate the location and length of tears and the presence of associated capsular defects. Arthrographic MR images may also enable the accurate diagnosis of cartilage lesions and intra-articular loose bodies. This article illustrates normal arthrographic MR features of the hip as well as pathologic disorders of the acetabular labrum, capsule, and articular cartilage     

Metatarsophalangeal joint of the great toe: normal MR,MR arthrographic,and MR bursographic findings in cadavers

OBJECTIVE: To demonstrate the normal anatomy of the metatarsophalangeal (MTP) joint of the great toe with MR imaging, MR arthrography, and MR bursography. MATERIALS AND METHODS: MR images of 12 cadaveric MTP joints of the great toe were obtained before and after arthrography, busography, or both. The MR appearances of all articular and periarticular structures were analyzed and correlated with those seen on anatomic sections. RESULTS: The sesamoid bones and ligaments, the deep transverse metatarsal ligament, and the tendon attachments of the abductor and adductor hallucis muscles were seen best in the coronal plane. The sagittal plane was best for evaluating the plantar plate, the articular cartilage, and the tendon attachments of the flexor and extensor hallucis brevis muscles. The main collateral ligaments were evaluated best in the axial plane. MR arthrography improved the visualization of all articular and periarticular structures except the collateral ligament complexes. MR bursography did not enhance the visualization of these structures. CONCLUSIONS: MR imaging and MR arthrography allow accurate visualization of the important anatomic structures in and about the MTP joint of the great toe.     

MR imaging of the metacarpophalangeal joints of the fingers: part I. Conventional MR imaging and MR arthrographic findings in cadavers

PURPOSE: To demonstrate the normal anatomy of the metacarpophalangeal (MCP) joints of the fingers with magnetic resonance (MR) imaging and MR arthrography in cadavers. MATERIALS AND METHODS: MR images of 20 MCP joints of the fingers of five fresh human cadaveric hands in the extended and flexed positions were obtained before and after arthrography. The MR appearances of all articular and periarticular structures were analyzed and compared with those seen on anatomic sections. Two readers independently graded the visibility of these structures. Interobserver agreement was tested by using the kappa statistic. RESULTS: The main collateral ligaments could be best evaluated on the transverse images of flexed fingers. The accessory bands of the collateral ligament complex were best seen on the transverse images of extended fingers. Sagittal MR images were best for evaluating the palmar plate and the capsule. MR arthrography improved the visualization of all articular and periarticular structures. The kappa values related to conventional MR imaging findings at all sequences, 0.42-0.71, indicated moderate to substantial agreement. The kappa values for the MR arthrographic sequences, 0.59-0.74, were slightly higher than those for the nonenhanced sequences. CONCLUSION: Conventional MR imaging and MR arthrography enable accurate visualization of the important anatomic structures of the MCP joints. MR arthrography enhances visualization of the intraarticular elements.     

Comparison of multislice CT arthrography and MR arthrography for the detection of articular cartilage lesions of the elbow

The objective of this study was to compare the value of multislice CT arthrography and MR arthrography in the assessment of cartilage lesions of the elbow joint. Twenty-six cadaveric elbow specimens were examined with the use of CT arthrography and MR arthrography prior to joint exploration and macroscopic inspection of articular cartilage. Findings at CT and MR arthrography were compared with macroscopic assessments in 104 cartilage areas. At macroscopic inspection, 45 cartilage lesions (six grade 2 lesions, 25 grade 3 lesions, 14 grade 4 lesions) and 59 areas of normal articular cartilage were observed. With macroscopic assessment as the gold standard CT and MR arthrography showed an overall sensitivity/specificity of 80/93% and 78/95% for the detection of cartilage lesions, respectively. Only two of six grade 2 lesions were detected by CT and MR arthrography. For the diagnosis of grade 3 and 4 lesions, the sensitivity/specificity was 87/94% with CT arthrography, and 85/95% with MR arthrography. In an experimental setting multislice CT arthrography and MR arthrography showed a similar performance in the detection of cartilage lesions. Both methods indicated limited value in the diagnosis of grade 2 articular cartilage lesions.     

Direct MR arthrography of the hip with leg traction: feasibility for assessing articular cartilage

OBJECTIVE: Hip arthrography is an accurate diagnostic method for evaluation of the peripheral compartment, but its depiction of cartilage lesions is moderate. The purpose of this study was to add leg traction to MR arthrography of the hip to test its effect on visualization of cartilage surfaces. CONCLUSION: Hip MR arthrography with leg traction is a technically feasible and safe procedure that improves visualization of the femoral and acetabular cartilage surfaces.     

3.0T常规MRI与MR髋关节造影诊断髋臼唇撕裂的对比研究

目的 在3.0 T场强中,比较常规髋关节MRI及MR髋关节造影对髋臼唇撕裂的诊断价值.方法 回顾分析44例髋关节病变患者的患侧髋关节常规MRI及MR髋关节造影资料,将每例患者的臼唇划分为前、上、后3处区域(共计132处),确定有无撕裂,并进行分型.其中5例患者经髋关节镜检查.对于常规MRI及MR髋关节造影获得的臼唇撕裂及分型数据差异比较采用Wilcoxon秩和检验,一致性比较采用Kappa检验.结果 常规MRI与MR髋关节造影诊断完全相同者计116处臼唇,只有16处存在诊断差异.其中,前者诊断无撕裂而后者诊断撕裂者9处,前者诊断撕裂但后者诊断无撕裂者6处,其余1处两者均诊断为撕裂但分型不同.常规MRI与MR髋关节造影的评价差异没有统计学意义(Z=0.347,P＞0.05),且具有极好的一致性(K=0.781,P＜0.01).在接受关节镜的5例患者中,常规MRI、MR髋关节造影及关节镜结果均完全吻合.结论 对髋臼唇撕裂,3.0 T常规髋关节MRI可获得与MR髋关节造影基本相同的诊断效果.     

Evaluation of the acetabular labrum at 3.0-T MR imaging compared with 1.5-T MR arthrography: preliminary experience

Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. The purpose of this study was to prospectively compare imaging of the acetabular labrum with 3.0-T magnetic resonance (MR) imaging and 1.5-T MR arthrography. Eight patients (four male, four female; mean age, 38 years) with hip pain suspicious for labral disease were examined at both MR arthrography and MR imaging. Presence of labral lesions, paralabral cysts, articular cartilage lesions, subchondral cysts, osteophytes, and synovial herniation pits was recorded. There was arthroscopic correlation of findings in five patients. MR imaging depicted four surgically confirmed labral tears that were identified at MR arthrography, as well as one that was not visualized at MR arthrography. MR imaging helped identify all other pathologic conditions that were diagnosed at MR arthrography and helped identify one additional surgically confirmed focal articular cartilage lesion. These results provide encouraging support for evaluation with 3.0-T MR imaging over 1.5-T MR arthrography.     

Magnetic resonance imaging of cartilage and cartilage repair

Magnetic resonance (MR) imaging of articular cartilage has assumed increased importance because of the prevalence of cartilage injury and degeneration, as well as the development of new surgical and pharmacological techniques to treat damaged cartilage. This article will review relevant aspects of the structure and biochemistry of cartilage that are important for understanding MR imaging of cartilage, describe optimal MR pulse sequences for its evaluation, and review the role of experimental quantitative MR techniques. These MR aspects are applied to clinical scenarios, including traumatic chondral injury, osteoarthritis, inflammatory arthritis, and cartilage repair procedures.     

Subluxation of the patella: evaluation of patellar articular cartilage with MR imaging.

In patients with subluxation of the patella, injury of the patellar articular cartilage is frequently observed, and correct evaluation of this cartilage injury is extremely important for the management of these patients. Magnetic Resonance (MR) studies were performed on 102 patellofemoral (PF) joints of 51 patients with subluxation of the patella and 20 PF joints of 10 healthy volunteers. In 77 of the 102 PF joints with subluxation, arthroscopy and/or operation were performed. MR images were obtained with spin-echo and FLASH sequences, and para-axial images were obtained. We retrospectively analysed the MR findings of the 77 joints with special attention to the surface and thickness of the cartilage, and classified them into four grades. These MR grades were compared with the grades on arthroscopy, and the following results were obtained: MR grade 0, normal cartilage (n = 27, sensitivity 90.9%, specificity 74.2%); MR grade 1, thickening of the cartilage (n = 24, sensitivity 50%, specificity 89.1%); MR grade 2, surface irregularity of the cartilage (n = 20, sensitivity 85%, specificity 94.7%); MR grade 3, loss of the cartilage (n = 6, sensitivity 100%, specificity 100%). Although the early changes observed by arthroscopy were underestimated from the MR images, MR imaging proved to be extremely useful for evaluating moderately or advanced patellar cartilage injury.     

Lesser metatarsophalangeal joints: standard MR imaging,MR arthrography,and MR bursography--initial results in 48 cadaveric joints

PURPOSE: To delineate the normal magnetic resonance (MR) imaging anatomy of the lesser metatarsophalangeal (MTP) joints in a cadaveric model and compare the MR arthrographic and MR bursographic findings with the standard MR imaging findings. MATERIALS AND METHODS: T1-weighted spin-echo MR imaging of 48 lesser MTP joints of 12 cadaveric feet was performed. The specimens were subsequently evaluated with MR arthrography, MR bursography, or both examinations. Musculoskeletal radiologists evaluated standard MR images to determine the normal appearances of the joint structures, especially the fibrous capsule, plantar plate, and collateral ligament complex (CLC). Signal intensity, morphology, joint thickness, relationships with adjacent structures, and best plane for analysis were analyzed. The contrast material-enhanced (ie, arthrographic and bursographic) MR imaging findings were compared with the standard MR imaging findings. RESULTS: The coronal plane was best for simultaneous depiction of the fibrous capsule, plantar plate, and collateral ligament complex and for assessment of the relationship between the CLC and the plantar plate. The sagittal plane was best for analysis of the bone attachments of the plantar plate and the transverse plane for evaluation of the CLC attachment sites in the phalanges. MR arthrography enabled identification of the bare areas and recesses of the joints, better delineation of the plantar plate articular surface, and better evaluation of the integrity of the soft-tissue components of the joints. Compared with the other examinations, MR bursography did not help improve these evaluations. CONCLUSION: MR imaging is an excellent examination for delineating the anatomy of the lesser MTP joints. Compared with standard MR imaging, only MR arthrography helps improve visualization of the fibrous capsule, plantar plate, and CLC of the lesser MTP joints.     

MRI of articular cartilage: revisiting current status and future directions

OBJECTIVE: The purpose of this article is to review the current understanding of the MRI appearance of articular cartilage and its relationship to the microscopic and macroscopic structure of articular cartilage, the optimal pulse sequences to be used in imaging, the appearance of both degenerative and traumatic chondral lesions, the appearance of the most common cartilage repair procedures, and future directions and developments in cartilage imaging. CONCLUSION: Articular cartilage plays an essential role in the function of the diarthrodial joints of the body but is frequently the target of degeneration or traumatic injury. The recent development of several surgical procedures that hold the promise of forming repair tissue that is hyaline or hyalinelike cartilage has increased the need for accurate, noninvasive assessment of both native articular cartilage and postoperative repair tissue. MRI is the optimal noninvasive method for assessment of articular cartilage.     

MR imaging of cartilage repair surgery of the knee

Articular cartilage is a complex tissue with unique properties that are essential for normal joint function. Many processes can result in cartilage injury, ranging from acute trauma to degenerative processes. Articular cartilage lacks vascularity, and therefore most chondral defects do not heal spontaneously and may require surgical repair. A variety of cartilage repair techniques have been developed and include bone marrow stimulation (microfracture), osteochondral autograft transfer system (OATS) or osteochondral allograft transplantation, autologous chondrocyte implantation (ACI), matrix-assisted chondrocyte implantation (MACI), and other newer processed allograft cartilage techniques. Although arthroscopy has long been considered as the gold standard for evaluation of cartilage after cartilage repair, magnetic resonance (MR) imaging is a non-invasive method to assess the repair site and can be scored using Magnetic resonance Observation of Cartilage Repair Tissue (MOCART). MR also provides additional evaluation of the subchondral bone and for other potential causes of knee pain or internal derangement. Conventional MR can be used to evaluate the status of cartilage repair and potential complications. Compositional MR sequences can provide supplementary information about the biochemical contents of the reparative tissue. This article reviews the various types of cartilage repair surgeries and their postoperative MR imaging appearances.     

MR imaging of cartilage repair surgery of the knee

Articular cartilage is a complex tissue with unique properties that are essential for normal joint function. Many processes can result in cartilage injury, ranging from acute trauma to degenerative processes. Articular cartilage lacks vascularity, and therefore most chondral defects do not heal spontaneously and may require surgical repair. A variety of cartilage repair techniques have been developed and include bone marrow stimulation (microfracture), osteochondral autograft transfer system (OATS) or osteochondral allograft transplantation, autologous chondrocyte implantation (ACI), matrix-assisted chondrocyte implantation (MACI), and other newer processed allograft cartilage techniques. Although arthroscopy has long been considered as the gold standard for evaluation of cartilage after cartilage repair, magnetic resonance (MR) imaging is a non-invasive method to assess the repair site and can be scored using Magnetic resonance Observation of Cartilage Repair Tissue (MOCART). MR also provides additional evaluation of the subchondral bone and for other potential causes of knee pain or internal derangement. Conventional MR can be used to evaluate the status of cartilage repair and potential complications. Compositional MR sequences can provide supplementary information about the biochemical contents of the reparative tissue. This article reviews the various types of cartilage repair surgeries and their postoperative MR imaging appearances.     

MR and CT arthrography of the knee

MR and CT arthrography are important imaging modalities for the assessment of the knee in certain situations. Indications for MR arthrography of the knee include assessment of the postoperative meniscus, the presence of chondral and osteochondral lesions, and the presence of intra-articular bodies. The major indication for CT arthrography is evaluating suspected internal derangement in patients who are unable to undergo MRI. In addition to reviewing the established clinical indications for MR and CT arthrography of the knee, the commonly used techniques, normal variants that can simulate disease, and the most commonly found pathologies that can be diagnosed with these modalities are discussed. Potential indications that are not currently well established in the literature including the evaluation of anterior cruciate ligament injury and autologous chondrocyte implants are examined. Where appropriate, the literature on controversial topics or diagnoses is reviewed. The use of conventional imaging versus CT and MR arthrography is also compared.     

弥散法MR膝关节造影可行性研究

目的评价MR对比剂静脉内注射、膝关节腔内弥散关节造影的可行性研究并寻找最佳检查参数. 资料与方法选取膝关节正常者24名,按常规方法进行扫描后再将其分为运动组和未运动组.每组再分为3小组.3个小组分别从静脉注入不同剂量的Gd-DTPA.注射完后未运动组受检者静卧于检查床,进行延迟扫描;运动组步行10 min后再进行扫描,并进行延迟.扫描结束后,对平扫和增强图像中的关节腔周围组织及关节腔内信号进行测量.采集后的数据按组归类,并进行统计处理,观察对比剂注射后关节腔内信号增加程度并选取最佳检查方法. 结果弥散法膝关节造影可使关节腔信号强度明显增加,与周围组织产生明显信号差,以采用注射剂量为0.2 mmol/kg体重,注射后受检者正常步行10 min后造影效果最佳. 结论弥散法MR膝关节造影可起到关节造影的效果,造影效果良好,是一种操作简单、危险性小、并发症少的检查方法.     

质子加权预饱和脂肪抑制序列对膝关节软骨损伤的诊断与关节镜对照研究

目的：比较质子加权预饱和脂肪抑制序列（PDW-FS）和自旋回波T2WI对诊断膝关节软骨损伤的准确性,探讨PDW-FS对软骨损伤的诊断价值。方法：对关节镜探查手术的37例45只膝关节,术前行MR检查,作回顾性分析,比较PDW-FS、T2WI序列诊断软骨损伤的价值。结果：以关节镜为标准,PDW-FS和T2WI序列的Kappa值分别为0.88和0.68,PDW-SF检查结果与关节镜结果一致性好。PDW-FS敏感度89.7%,特异度97.1%,T2WI敏感度79.1%,特异度94.8%,差异有统计学意义（χ2=4.50,P〈0.05）。结论：PDW-FS序列诊断膝关节软骨损伤的准确性优于T2WI,可准确地判断软骨损伤的范围和深度,为临床医生选择合适的治疗方案提供可靠依据。     

Assessment of knee cartilage in cadavers with dual-detector spiral CT arthrography and MR imaging

PURPOSE: To assess dual-detector spiral CT arthrography in the evaluation of the entire knee cartilage obtained from cadavers. MATERIALS AND METHODS: Two independent observers characterized articular cartilage in 12 cadaver knees in which MR imaging and dual-detector spiral CT arthrography were performed and compared their findings to those found during macroscopic assessment. The sensitivity and specificity of MR imaging and spiral CT arthrography for detecting grade 2A or higher and grade 2B or higher cartilage lesions, the Spearman correlation coefficient between arthrographic and macroscopic grading, and kappa statistics for assessing interobserver reproducibility were determined. RESULTS: At spiral CT arthrography, sensitivities and specificities ranged between 80% and 88% for the detection of grade 2A or higher cartilage lesions and ranged between 85% and 94% for the detection of grade 2B or higher cartilage lesions. At MR imaging, sensitivities and specificities ranged between 78% and 86% and between 76% and 91% for the detection of grade 2A or higher and grade 2B or higher cartilage lesions, respectively. Spearman correlation coefficients between spiral CT arthrography or MR imaging and macroscopic grading of articular surfaces were 0.797 and 0.702, respectively. CONCLUSION: Dual-detector spiral CT arthrography of the knee is a valuable method for the assessment of open cartilage lesions of the entire knee.     

Magnetic resonance imaging ofarticular cartilage injuries of the knee

Magnetic resonance imaging (MRI) is a widely available, powerful imaging modality in the United States that has rapidly become a mainstay for evaluation of the musculoskeletal system, largely because of its unparalleled depiction of most osseous and soft-tissue pathology. The application of MRI to detect cartilage injuries has evolved to the point where it is possible to noninvasively diagnose cartilage lesions that previously required an invasive examination, eg, arthrography or arthroscopy. However, successful cartilage imaging requires knowledge of the unique technical considerations and limitations of MRI. In this chapter we review current state-of-the-art knee MRI for three groups of chondral disorders: acute osteochondral fractures, osteochondritis dissecans, and degenerative lesions. The role of MRI in osteochondral fractures includes the demonstration of purely chondral intra-articular fragments and the identification of associated injuries, especially previously unrecognized subchondral bruises. MRI may also play a role in surveillance for osteochondral sequelae after injury. For osteochondritis dissecans, MRI can provide evidence supporting the diagnosis of a loose fragment and may aid in the evaluation of cartilage overlying osteochondral defects. Current MRI techniques can show moderate and severe lesions of chondromalacia and chondrosis. Newer techniques show potential for diagnosing these degenerative conditions at earlier stages when the changes are mild. We review these issues and provide examples showing the MRI appearance of common articular injuries.