Imaging of the articular cartilage in osteoarthritis of the knee joint: 3D spatial-spectral spoiled gradient-echo vs. fat-suppressed 3D spoiled gradient-echo MR imaging

PURPOSE: To compare three-dimensional (3D) spatial-spectral (SS) spoiled gradient-recalled acquisition in the steady state (SPGR) imaging with fat-suppressed 3D SPGR sequences in MR imaging of articular cartilage of the knee joint in patients with osteoarthritis. MATERIALS AND METHODS: MR images of six patients with osteoarthritis of the knee were prospectively examined with a 1.5T MR scanner. For quantitative analyses, the signal-to-noise ratios, contrast-to-noise ratios, and contrast of cartilage and adjacent structures including meniscus, synovial fluid, muscle, fat tissue, and bone marrow were measured. RESULTS: In patients with osteoarthritis, 3DSS-SPGR images demonstrated higher spatial resolution and higher mean signal-to-noise (S/N) ratios (cartilage, 24.9; synovial fluid, 12.3; muscle, 20.7; meniscus, 21.6), with shorter acquisition times (7 minutes 20 seconds), when compared to fat-suppressed 3D SPGR images (cartilage, 22.3; synovial fluid, 10.8; muscle, 16.7; meniscus, 13.4). CONCLUSION: 3DSS-SPGR imaging is a promising method for evaluating cartilage pathology in patients with osteoarthritis of the knee and has the potential to replace fat-suppressed 3D SPGR imaging.     

MR imaging of articular cartilage

With the advent of new treatments for articular cartilage disorders, accurate noninvasive assessment of articular cartilage, particularly with MR imaging, has become important. Understanding the MR imaging features of articular cartilage has led to the development of two types of routinely available MR imaging techniques which have demonstrated clinical accuracy and interobserver reliability. Received: 25 January 2000 Revision requested: 21 March 2000 Revision received: 31 March 2000 Accepted: 3 April 2000     

Variations in meniscofemoral ligaments at anatomical study and MR imaging

Purpose To demonstrate variations in the meniscofemoral ligaments (ligaments of Wrisberg and Humphrey) at anatomical study and magnetic resonance (MR) imaging. Design Twenty-eight cadaveric knees were partially dissected for the examination of the meniscofemoral ligaments. One hundred knee MR examinations were reviewed by two experienced musculoskeletal radiologists. Proximal variations in the meniscofemoral ligaments at MR imaging were classified into three types according to the attachment site: type I, medial femoral condyle; type II, proximal half of the posterior cruciate ligament (PCL); type III, distal half of the PCL. Distal variations were classified into vertical or oblique types according to the orientation of the intermediate signal at the interface of the ligament and lateral meniscus. Results At anatomical study, six cases showed variations in the proximal insertion site of the meniscofemoral ligaments. At MR imaging 93 cases had one or more meniscofemoral ligaments, giving a total of 107 ligaments: 90 ligaments of Wrisberg and 17 ligaments of Humphrey. Forty-one ligaments of Wrisberg were type I, 28 type II, 19 type III, and with two indeterminate type, while 6 ligaments of Humphrey were type I and the remaining 11 were indeterminate. Seven cases showed no meniscofemoral ligament. Of the 107 meniscofemoral ligaments, the distal insertion orientation was of vertical type in 10 ligaments, oblique type in 70 and unidentified in 27. Conclusion An understanding of the high incidence of meniscofemoral ligament variations may help in the interpretation of knee MR studies. Received: 16 February 1998 Revision requested: 16 June 1998 Revision received: 6 October 1998 Accepted: 7 December 1998     

MR imaging of hyaline cartilage at 0.5 T: a quantitative and qualitative in vitro evaluation of three types of sequences

Objective. To identify an optimal pulse sequence for in vitro imaging of hyaline cartilage at 0.5 T. Materials and methods. Twelve holes of varying diameter and depth were drilled in cartilage of two pig knees. These were submerged in saline and scanned with a 0.5-T MR system. Sixteen T1-weighted gradient echo (GE), two T2-weighted GE, and 16 fast spin echo sequences were used, by varying repetition time (TR), echo time (TE), flip angle (FA), echo train length, profile order, and by use of fat saturation. Contrast-to-noise ratios (CNR) of cartilage versus saline solution and cartilage versus subchondral bone were measured. Cartilaginous lesions were evaluated separately by three independent observers. Interobserver variability and correlation between the quantitative and qualitative analyses were calculated. Results. The mean CNRs of two specimens of cartilage versus saline solution ranged from 6.3 (±2.1) to 27.7 (±2.5), and those of cartilage versus subchondral bone from 0.3 (±0.2) to 22.5 (±1.4). The highest CNR was obtained with a T1-weighted spoiled 3D-GE technique (TR 65 ms, TE 11.5 ms, FA 45°). The number of lesions observed per sequence varied from 35 to 69. Observer agreement was fair to good. The T1-weighted spoiled GE sequences with a TR of 65 ms, TE of 11.5 ms and FA of 30° and 45° were significantly superior to the other 34 sequences in the qualitative analysis. Conclusion. T1-weighted spoiled 3D-GE sequences with a TR of 65 ms, a TE of 11.5 ms, and a FA of 30–45° were found to be optimal for in vitro imaging of cartilage at 0.5 T.     

Texture analysis of articular cartilage traumatic changes in the knee calculated from morphological 3.0 T MR imaging

Objectives

In the present work, we aim to identify changes in the cartilage texture of the injured knee in young, physically active, patients by computer analysis of MRI images based on 3.0 T morphological sequences.

Methods

Fifty-three young patients with training injury or trauma in one knee underwent MRI and arthroscopy. Textural features were computed from the MRI images of the knee-cartilages and two classes were formed of 28 normal and 16 with pathology only in the medial femoral condyle (MFC) cartilage.

Results

Textural features with statistically significant differences between the two classes were found only at the MFC and the medial tibial condyle (MTC) areas. Three features-combinations, at the MFC or the MTC, maximized the between classes separation, thus, rendering alterations in cartilage texture due to injury more evident. The MFC cartilage in the pathology class was found more inhomogeneous in the distribution of gray-levels and of lower texture anisotropy and the opposed MTC cartilage, though normal on MRI and arthroscopy, was found to have lower texture anisotropy than cartilage in the normal class.

Conclusion

Texture analysis may be used as an adjunct to morphological MR imaging for improving the detection of subtle cartilage changes and contributes to early therapeutic approach.     

Gender differences in knee joint cartilage thickness, volume and articular surface areas: assessment with quantitative three-dimensional MR imaging

Objective: To compare the cartilage thickness, volume, and articular surface areas of the knee joint between young healthy, non-athletic female and male individuals. Subjects and design. MR imaging was performed in 18 healthy subjects without local or systemic joint disease (9 female, age 22.3±2.4 years, and 9 male, age 22.2±1.9 years.), using a fat-suppressed FLASH 3D pulse sequence (TR=41 ms, TE=11 ms, FA=30°) with sagittal orien- tation and a spatial resolution of 2×0.31×0.31 mm³. After three- dimensional reconstruction and triangulation of the knee joint cartilage plates, the cartilage thickness (mean and maximal), volume, and size of the articular surface area were quantified, independent of the original section orientation. Results and conclusions: Women displayed smaller cartilage volumes than men, the percentage difference ranging from 19.9% in the patella, to 46.6% in the medial tibia. The gender differences of the cartilage thickness were smaller, ranging from 2.0% in the femoral trochlea to 13.3% in the medial tibia for the mean thickness, and from 4.3% in the medial femoral condyle to 18.3% in the medial tibia for the maximal cartilage thickness. The differences between the cartilage surface areas were similar to those of the volumes, with values ranging from 21.0% in the femur to 33.4% in the lateral tibia. Gender differences could be reduced for cartilage volume and surface area when normalized to body weight and body weight×body height. The study demonstrates significant gender differences in cartilage volume and surface area of men and women, which need to be taken into account when retrospectively estimating articular cartilage loss in patients with symptoms of degenerative joint disease. Differences in cartilage volume are primarily due to differences in joint surface areas (epiphyseal bone size), not to differences in cartilage thickness. Received: 19 June 2000 Revision requested: 4 August 2000 Revision received: 30 November 2000 Accepted: 6 December 2000     

MRI of patellar articular cartilage: Evaluation of an optimized gradient-echo sequence (3D-DESS)

Our purpose was to evaluate the diagnostic efficacy of a gradient-echo sequence optimized for cartilage imaging in patellar cartilage abnormalities and to compare it to a standard turbo-spin-echo sequence. Fifty-eight consecutive patients who underwent, within 3 months both MRI and arthroscopy or surgery, were included in the investigation. Two radiologists specializing in musculoskeletal imaging independently assessed axial three-dimensional double-echo steady state (3D-DESS) gradient-echo images and sagittal proton- and T2-weighted turbo-spin-echo images with regard to retropatellar cartilage abnormalities. Possible findings were: 0: normal, 1: cartilage softening, and 2: lesion of the articular surface. Inter- and intraobserver variability was assessed. For cartilage softening, the axial 3D-DESS sequence had a sensitivity of 73%, a specifity of 75%, and an accuracy of 70%. The corresponding results for the sagittal turbo-spin-echo sequence were 53%, 65%, and 62%. For surface lesions, the results for the 3D-DESS sequence were 43%, 92%, and 83% and for the turbo-spin-echo sequence were 60%, 92%, and 86%. Intra- and interobserver agreement was moderate (k = 0.59 and 0.45 [DESS], 0.6 and 0.46 [turbo -spin-echo]). We conclude that the 3D-DESS sequence is moderately accurate in detecting patellar cartilage abnormalities. Compared with the sagittal turbo-spin-echo sequence, the axial 3D-DESS sequence is superior in diagnosing cartilage softening but not surface lesions.     

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.     

Chondromalacia of the knee: Evaluation with a fat-suppression three-dimensional SPGR imaging after intravenous contrast injection

Twenty-one MRI studies with a fat-suppression three-dimensional spoiled gradient-recalled echo in a steady state (3D SPGR) pulse sequence after intravenous contrast injection were evaluated to assess the accuracy in depicting chondromalacia of the knee. On the basis of MR images, chondromalacia and its grade were determined in each of five articular cartilage regions (total, 105 regions) and then the results were compared to arthroscopic findings. The sensitivity, specificity, and accuracy of MRI were 70%, 99%, and 93%, respectively. MR images depicted 7 of 11 lesions of arthroscopic grade 1 or 2 chondromalacia, and seven of nine lesions of arthroscopic grade 3 or 4 chondromalacia. The cartilage abnormalities in all cases appeared as focal lesions with high signal intensity. Intravenous contrast-injection, fat-suppression 3D SPGR imaging showed high specificity in excluding cartilage abnormalities and may be considered as an alternative to intra-articular MR arthrography when chondromalacia is suspected.     

Magnetic resonance imaging of the brain with gadopentetate dimeglumine-DTPA: Comparison of T1-weighted spin-echo and 3D gradient-echo sequences

Short TR, short TE, high resolution, 3D gradient-recalled echo (GRE) imaging was evaluated for lesion detection in the brain. High resolution 3D GRE data acquisition was used to reduce partial volume effects and flow artifacts, to better visualize smaller structures, to minimize signal losses caused by field inhomogeneities, and to allow better image reformatting. Spin-echo (SE) and 3D GRE approaches were compared for lesion detection after the administration of an MR contrast agent, gadopentetate dimeglumine. Preliminary clinical studies demonstrated that the signal-to-noise ratio (SNR) in each slice of the GRE scan was worse than that of the SE scan because of the much thicker slices acquired with the SE technique. However, by averaging two adjacent 3D slices, the SNR of the two methods was essentially equivalent. In the averaged GRE slices, large lesions were seen just as well as in the SE images. More importantly, small lesions were better visualized in the thin 3D GRE images than in the thick SE images for the lesions studied in this work and the protocols used. These observations were confirmed by theoretical simulations.     

Assessment of normal patellar cartilage volume and thickness using MRI: an analysis of currently available pulse sequences

 Objective. The objective of this study was to analyse the potential of magnetic resonance imaging for valid determination of patellar cartilage thickness, comparing currently available pulse sequences. Design. In six patients and one cadaver the cartilage was repetitively imaged employing three spin-echo and six three-dimensional gradient-echo sequences. In the cadaveric specimen the total volume and the regional distribution of cartilage thickness were assessed and compared with the values obtained from anatomical sections by image analysis. Results and conclusions. The FLASH and fat-suppressed FLASH sequences allowed the most accurate determination of the cartilage volume and thickness. Fat-suppression considerably increased the contrast of the cartilage to the synovial fluid, fat and bone marrow, yielding higher reproducibility of the volumetric measurements. The remaining difference from the anatomical volume and thickness may be because the calcified cartilage is not delineated by magnetic resonance imaging.     

MR imaging of articular cartilage in the ankle: comparison of available imaging sequences and methods of measurement in cadavers

 Objective. To assess hyaline cartilage of cadaveric ankles using different magnetic resonance (MR) imaging techniques and various methods of measurement. Design and patients. Cartilage thicknesses of the talus and tibia were measured in ten cadaveric ankles by naked eye and by digitized image analysis from MR images of fat-suppressed T1-weighted gradient recalled (FS-SPGR), sequences and pulsed transfer saturation sequences with (FS-STS) and without fat-suppression (STS); these measurements were compared with those derived from direct inspection of cadaveric sections. The accuracy and precision errors were evaluated statistically for each imaging technique as well as measuring method. Contrast-to-noise ratios of cartilage versus joint fluid and marrow were compared for each of the imaging sequences. Results. Statistically, measurements from FS-SPGR images were associated with the smallest estimation error. Precision error of measurements derived from digitized image analysis was found to be smaller than that derived from naked eye measurements. Cartilage thickness measurements in images from STS and FS-STS sequences revealed larger errors in both accuracy and precision. Interobserver variance was larger in naked eye assessment of the cartilage. Contrast-to-noise ratio of cartilage versus joint fluid and marrow was higher with FS-SPGR than with FS-STS or STS sequences. Conclusion. Of the sequences and measurement techniques studied, the FS-SPGR sequence combined with the use of digitized image analysis provides the most accurate method for the assessment of ankle hyaline cartilage.     

T1 mapping联合常规MRI扫描方案评估膝关节软骨损伤

目的 评估在常规MRI扫描方案中加入T1 mapping成像能否提高对膝关节软骨损伤的诊断效能.方法 选取86例患者的88个膝关节接受了膝关节MRI检查和关节镜检查.MRI检查采用常规方案并加入T1 mapping成像.术前2位影像科医师对所有MRI检查图像进行一致的诊断,评估是否存在软骨损伤并进行软骨损伤MRI分级,...     

MR imaging evaluation of the postoperative knee: ligaments, menisci, and articular cartilage

The surgical management of knee injuries has increased in recent years. Postoperative magnetic resonance (MR) imaging of the knee following surgical intervention serves an important role in the diagnostic evaluation of patients with recurrent or residual symptoms following surgical intervention. MR imaging additionally assists in the noninvasive documentation of temporal changes at the surgical site potentially reflective of procedural success, or failure. Background understanding of the common surgical procedures performed, their normal postoperative MR imaging appearance, and imaging features of potential procedural complications are essential in the accurate evaluation of patients following prior knee surgery. The focus of the following article is to review the clinical and MR imaging features of the postoperative knee following prior surgical treatment of ligamentous, meniscal, and articular cartilage injuries of the joint.     

MR imaging evaluation of knee collateral ligaments and related injuries: Comparison of T1-weighted,T2-weighted,and fat-saturated T2-weighted sequences—correlation with clinical findings

The objectives of this study were to compare the ability of T1-weighted (T1W), proton density/T2-weighted (PD/T2W), and fat saturation (FS) PD/T2W magnetic resonance (MR) sequences for depiction of the knee collateral ligaments and related injuries, and to compare MR findings with clinical findings. Ten subjects with normal knee ligaments and 64 patients with suspected collateral ligament injuries underwent coronal T1W, PD/T2W, and FS PD/T2W imaging. Abnormalities ranged from edema surrounding the collateral ligaments (grade I) to complete disruption of ligamentous fibers (grade III). FS PD/T2W images improved definition of the medial collateral ligament (MCL) and lateral collateral ligament (LCL) compared with other sequences in 78% and 81% of patients, respectively. While the apparent grade of collateral ligament injury was similar with all pulse sequences in most patients, depiction of such injury was usually most conspicuous on FS PD/T2W images (MCL, 92% of patients; LCL, 38% of patients). In no patients were clinically diagnosed collateral ligament injuries undetected or understaged with MR imaging. MR findings indicated higher-grade MCL and LCL injuries than did clinical examination in 24 and 15 patients, respectively.     

Comparison of 3D vs. 2D fast spin echo imaging for evaluation of articular cartilage in the knee on a 3T system scientific research

Purpose

We sought to retrospectively compare the accuracy of a three-dimensional fat-suppressed, fast spin-echo sequences acquired in the sagittal plane, with multiplanar reconstructions to that of two-dimensional fat-suppressed, fast spin echo sequences acquired in three planes on a 3 T MR system for the evaluation of articular cartilage in the knee.

Materials and methods

Our study group consisted of all patients (N = 34) that underwent 3 T MR imaging of the knee at our institution with subsequent arthroscopy over an 18-month period. There were 21 males and 13 females with an average age of 36 years. MR images were reviewed by 3 musculoskeletal radiologists, blinded to operative results. 3D and 2D sequences were reviewed at different sittings separated by 4 weeks to prevent bias. Six cartilage surfaces were evaluated both with MR imaging and arthroscopically with a modified Noyes scoring system and arthroscopic results were used as the gold standard. Sensitivity, specificity, and accuracy were calculated for each reader along with Fleiss Kappa assessment agreement between the readers. Accuracies for each articular surface were compared using a difference in proportions test with a 95% confidence interval and statistical significance was calculated using a Fisher's Exact Test.

Results

Two hundred and four articular surfaces were evaluated and 49 articular cartilage lesions were present at arthroscopy. For the patellofemoral surfaces, the sensitivity, specificity, and accuracy were 76.5%, 83%, and 78.2% for the 3D sequences and were 82.3%, 76%, and 82% respectively for the 2D sequences. For the medial compartment surfaces, the sensitivity, specificity, and accuracy were 81.1%, 65.1%, and 78.5% for the 3D sequences and were 82.5%, 48%, and 76.7% respectively for the 2D sequences. For the lateral compartment surfaces, the sensitivity, specificity, and accuracy were 89.3%, 39%, and 79.5% for the 3D sequences and were 94.7%, 18.8%, and 79.5% respectively for the 2D sequences. The accuracies were not significantly different between 3D and 2D sequences. Fleiss Kappa agreement values for the assessment of inter-observer agreement ranged from substantial for the patella and medial femur to moderate for the trochlea and fair for the medial tibia and lateral compartment.

Conclusion

There was no significant difference in accuracy for the evaluation of articular cartilage of a single three-dimensional, fast spin echo sequence with multi-planar reformatted images vs. two-dimensional, fast spin echo sequences acquired in all three imaging planes in the knee.     

Signs of patellar chondromalacia on sagittal T2-weighted magnetic resonance imaging

We incidentally noted distinctive high signal defects or fissures in the patellar articular cartilage on sagittal T2-weighted magnetic resonance (MR) images in 4 patients. At subsequent arthroscopy all 4 patients were found to have patellar chondromalacia. To determine the reliability of these signs, we retrospectively evaluated, in a blinded manner, sagittal T2-weighted MR images of the knee in 75 patients who were undergoing arthroscopic assessment of their patellar articular cartilage. We identified high signal defects or fissures in the patellar cartilage of 5 patients. Patellar chondromalacia was noted at arthroscopy in all 5 patients. Arthroscopy demonstrated patellar chondromalacia in an additional 21 patients with normal MR images. We conclude that high signal defects or fissures on sagittal T2-weighted images are useful signs of patellar chondromalacia. This single imaging sequence will, however, detect only a small number of the cartilage lesions that may be present.     

水激励技术在关节软骨MR成像中的应用

目的 探讨水激励技术在关节软骨MR成像中的应用价值.方法 应用三维快速梯度回波水激励(3D-FFE-WATS)及三维快速梯度回波预饱和反转恢复法脂肪抑制(3D-FFE-SPIR)序列组合对15名健康志愿者进行单膝关节检查,计算关节软骨信号噪声比(SNR),软骨与周围组织的对比噪声比(CNR)及其效率值,统计分析试验结果.采用上述2种序列对29例疑诊关节软骨损伤的30个膝关节进行检查,综合分析各序列中软骨病变表现特征及其对病变的检出能力.结果 健康志愿者软骨SNR:3D-FFE-SPIR为197.93±18.58,3D-FFE-WATS为187.32±21.50(P=0.159);软骨与骨皮质CNR:3D-FFE-SPIR为185.50±18.34,3D-FFE-WATS为169.55±24.57(P=0.054);软骨与肌肉CNR:3D-FFE-SPIR为61.40±19.04,3D-FFE-WATS为47.27±21.05(P=0.064),差异均无统计学意义.软骨与液体CNR:3D-FFE-SPIR为91.53±14.46,3D-FFE-WATS为149.28±32.30(P=0.000);软骨与骨髓CNR:3D-FFE-SPIR为159.26±18.83,3D-FFE-WATS:176.87±22.50(P=0.028);软骨与脂肪CNR:3D-FFE-SPIR为134.56±15.80,3D-FFE-WATS为154.01±22.42(P=0.010),差异均有统计学意义.30个膝关节病变中,2种序列分别对损伤的检出:3D-FFE-WATS为39处,3D-FFE-SPIR为45处,两者间差异无统计学意义(P=0.37).结论 3D-FFE-WATS序列可清晰显示关节软骨,脂肪抑制均匀,扫描速度快,病变检出率高,可用于常规临床检查.     

Anterior Cruciate Ligament Tear: Reliability of MR Imaging to Predict Stability after Conservative Treatment

Objective

The aim of this study is to evaluate the reliability of MR imaging to predict the stability of the torn anterior cruciate ligament (ACL) after complete recovery of the ligament''s continuity.

Materials and Methods

Twenty patients with 20 knee injuries (13 males and 7 females; age range, 20-54) were enrolled in the study. The inclusion criteria were a positive history of acute trauma, diagnosis of the ACL tear by both the physical examination and the MR imaging at the initial presentation, conservative treatment, complete recovery of the continuity of the ligament on the follow up (FU) MR images and availability of the KT-2000 measurements. Two radiologists, who worked in consensus, graded the MR findings with using a 3-point system for the signal intensity, sharpness, straightness and the thickness of the healed ligament. The insufficiency of ACL was categorized into three groups according to the KT-2000 measurements. The statistic correlations between the grades of the MR findings and the degrees of ACL insufficiency were analyzed using the Cochran-Mantel-Haenszel test (p < 0.05).

Results

The p-values for each category of the MR findings according to the different groups of the KT-2000 measurements were 0.9180 for the MR signal intensity, 1.0000 for sharpness, 0.5038 for straightness and 0.2950 for thickness of the ACL. The MR findings were not significantly different between the different KT-2000 groups.

Conclusion

MR imaging itself is not a reliable examination to predict stability of the ACL rupture outcome, even when the MR images show an intact appearance of the ACL.     

MRI of the knee: value of short echo time fast spin-echo using high performance gradients versus conventional spin-echo imaging for the detection of meniscal tears

Objective. Fast spin-echo (FSE) sequences reduce imaging time compared with conventional spin-echo (CSE) sequences, but may result in blurring. High-performance gradients permit shorter interecho spacing and use of the second echo as the effective TE (20 ms); both improvements reduce blurring. This randomized observer study compared a short TE, second-echo FSE sequence obtained using high-performance gradients and a CSE sequence with similar TR/TE for the detection of meniscal tears in the knee. Design and patients. One hundred consecutive MR examinations of the knee using FSE and CSE sequences at 1.5 T were evaluated. The FSE sequence used an effective TE of 20 ms (centered on the second echo at 2 times minimal interecho spacing) and an echo train length of 4. FSE and CSE parameters were otherwise similar. Four independent, masked readers reviewed randomized sagittal FSE and CSE sequences. Results. Cases were assessed for the presence or absence of meniscal tears and, if present, whether tears were medial or lateral and anterior or posterior. Sequence concordance was 93.5% (1496 of 1600 meniscal segments); the intermethod kappa value was 0.78. Sequence quality was graded from 1 to 5. Average quality of CSE images was slightly but statistically significantly preferred by three of the four readers. Conclusion. There was no statistically significant difference between CSE imaging and FSE imaging centered on the second echo (20 ms) using high-performance gradients for the detection of meniscal tears in the knee. There was a small preference for the quality of CSE images. Received: 22 July 1999 Revision requested: 27 October 1999 Revision received: 7 February 2000 Accepted: 21 March 2000