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

Ex Vivo Comparison of the Diagnostic Performance of Two-Dimensional and Three-Dimensional Three-Tesla Magnetic Resonance Imaging Sequences in Depicting Normal Articular Cartilage in Equine Stifle Cadavers

The objective of this study was to compare articular cartilage thickness observed in the different 2D and 3D sequences to the cartilage thickness of the equine stifle in cadavers to determine the accuracy of each sequence. The study was conducted as a blinded laboratory study using seven equine stifle specimens. The 2D (T2W TSE) and 3D (3D VIEW T2W HR, T2 3D mFFE, T1W VISTA SPAIR, 3D PDW SPAIR) 3-tesla MRI sequences of each stifle were obtained. Cartilage thickness was measured at 30 locations on MRI and on gross pathology. Thickness measurements were compared using a Bland-Altman plot and post hoc analysis tests. The 3D sequences were found to be generally more accurate than the 2D sequence (p < 0.001). The smallest difference to macroscopic measurements was observed in the 3D VIEW T2W HR and T1W VISTA SPAIR sequences with no statistical difference between each other. Knowing the accuracy of different sequences will improve the evaluation of equine cartilage and the early detection of cartilage pathologies. This would promote MRI as a noninvasive imaging modality for horses suffering from stifle lameness with no findings in conventional imaging methods. Furthermore, since 3D sequences seem to have better accuracy in depicting cartilage, they may replace 2D sequences, thereby shortening scanning times.

Magnetic resonance imaging is able to detect patellofemoral focal cartilage injuries: a systematic review with meta-analysis

PURPOSE

The purpose of this study was to analyze the diagnostic accuracy of magnetic resonance imaging (MRI) to detect and grade the severity of patellofemoral (PF) cartilage injuries.

METHODS

A systematic review was conducted on PubMed, EMBASE and Cochrane Library databases (up to July 1st 2022) to search for studies that reported the diagnostic accuracy of MRI to detect and grade PF cartilage injuries as compared to diagnostic arthroscopy. Risk of bias was judged using the QUADAS-2 tool. Quantitative syntheses were performed to calculate the diagnostic accuracy metric-sensitivity, specificity, positive likelihood (LR+) and negative likelihood (LR-) ratios, diagnostic odds ratio (DOR)-and presented as median with 25% and 75% percentiles. The summary receiver operating characteristic (SROC) curves were also calculated. Diagnostic accuracy metrics were calculated for all PF cartilage injuries and then sub-grouped by patellar and trochlear lesions. Diagnostic accuracy was also calculated according to the grading of cartilage injuries.

RESULTS

Forty-five studies were included for qualitative analyses and forty studies were included for quantitative synthesis. A total of 3534 participants with a weighted mean age of 38.1 years were included. Diagnostic accuracy was generally high: sensitivity (0.8, 0.6-1.0), specificity (0.9, 0.8-1.0), LR+ (6.4, 3.1-15.3), LR- (0.3, 0.2-0.4) and DOR (21.3, 9.9-121.1). The area under the curve (AUC) of the SROC was 0.9. The diagnostic accuracy was slightly higher for patellar (sensitivity 0.8, specificity 0.8, LR+ 5.3, LR- 0.2, DOR 28.8) than for trochlear lesions (sensitivity 0.7, specificity 0.9, LR+ 5.5, LR- 0.4, DOR 14.3). The sensitivity was generally higher when grading advanced (vs. early or intermediate) cartilage injuries of the patella.

CONCLUSION

The MRI is able to diagnose PF cartilage injuries with reasonably high diagnostic accuracy (as compared to arthroscopy). Clinicians can rely on MRI to reliably diagnose PF cartilage injuries (with some limitations) which will play an important role in deciding for surgical or non-operative treatment.

LEVEL OF EVIDENCE

Level III.

Clinical value of MRI in evaluating and diagnosing of humeral lateral condyle fracture in children

Background

Humeral lateral condyle fractures (HLCFs) are common paediatric fractures. Radiographs are hard to accurately evaluate and diagnose the damage of articular epiphyseal cartilage in HLCFs.

Methods

60 children who should be suspected to be HLCFs in clinical practice from Dec 2015 to Nov 2017 were continuously included as the first part patients. Subsequently, 35 HLCFs patients with complete follow-up information who had no obvious displacement on radiograph were the second part patients. The sensitivity and specificity of radiograph and MRI in diagnosing of HLCFs and their stability were calculated respectively. Calculated the sensitivity and specificity of each scan sequence of MRI in diagnosing of HLCFs osteochondral fractures. The degree of fracture displacement was measured respectively. Compared the ratio of surgical treatment, secondary fracture displacement and complications between the stable fracture group and the unstable fracture group on MRI in part 2 patients.

Results

Sensitivity of diagnosing HLCFs by MRI was significantly higher than radiograph (100.00% vs. 89.09%, P = 0.03). Sensitivity of diagnosing integrity of trochlear cartilage chain by MRI was 96.30%, which was significantly higher than that by radiograph (62.96%, P < 0.01). The sensitivity of cartilage sensitive sequence (3D-FS-FSPGR/3D-FSPGR) was different with FS-PDWI and FS-T2WI (P = 0.01 and P = 0.02, respectively). The degree of HLCFs displacement by MRI was higher than radiograph (P < 0.05). In the unstable fracture group, 5 cases (45.45%) had a fracture displacement of more than 2 mm on MRI, which was significantly higher than that in stable fracture group (0.00%, P < 0.01).

Conclusions

MRI is superior to the radiograph of elbow joint in evaluating and diagnosing children HLCFs and their stability. The coronal 3D-FS-FSPGR/3D-FSPGR sequence is a significant sequence for diagnosing osteochondral fractures in HLCFs. MRI can provide important clinical value for treatment decisions of HLCFs without significant displacement.

3D MRI of Articular Cartilage

Osteoarthritis, characterized by the breakdown of articular cartilage and other joint structures, is one of the most prevalent and disabling chronic diseases in the United States. Magnetic resonance imaging is a commonly used imaging modality to evaluate patients with joint pain. Both two-dimensional fast spin-echo sequences (2D-FSE) and three-dimensional (3D) sequences are used in clinical practice to evaluate articular cartilage. The 3D sequences have many advantages compared with 2D-FSE sequences, such as their high in-plane spatial resolution, thin continuous slices that reduce the effects of partial volume averaging, and ability to create multiplanar reformat images following a single acquisition. This article reviews the different 3D imaging techniques available for evaluating cartilage morphology, illustrates the strengths and weaknesses of 3D approaches compared with 2D-FSE approaches for cartilage imaging, and summarizes the diagnostic performance of 2D-FSE and 3D sequences for detecting cartilage lesions within the knee and hip joints.

Five-Minute Five-Sequence Knee MRI Using Combined Simultaneous Multislice and Parallel Imaging Acceleration: Comparison with 10-Minute Parallel Imaging Knee MRI

Background Rapid knee MRI using combined simultaneous multislice (SMS) technique and parallel imaging (PI) acceleration can add value through reduced acquisition time but requires validation of clinical efficacy. Purpose To evaluate the performance of clinical fourfold SMS-PI-accelerated, 5-minute, five-sequence, multicontrast knee MRI protocols compared with standard twofold PI-accelerated, 10-minute knee MRI protocols. Materials and Methods Adults with painful knee conditions were prospectively enrolled from April 2018 to October 2019. Participants underwent fourfold SMS-PI-accelerated, 5-minute, turbo spin-echo (TSE) knee MRI and standard-of-care twofold PI-accelerated, 10-minute, TSE knee MRI at either 1.5 T or 3.0 T. Three radiologists independently evaluated the knee MRI studies for meniscal, tendinous, ligamentous, and osseocartilaginous injuries. Statistical analyses included k-based intermethod agreements and diagnostic performance testing. P < .05 was considered indicative of a statistically significant difference. Results A total of 252 adults were evaluated (mean age ± standard deviation, 47 years ± 17; 134 men). Among the participants, 104 (mean age, 42 years ± 18; 57 women) were in the 1.5-T arm and 148 (mean age, 46 years ± 17; 87 men) were in the 3.0-T arm. Twenty-nine participants (mean age, 38 years ± 12; 15 men) in the 1.5-T arm and 42 (mean age, 41 years ± 16; 24 men) in the 3.0-T arm underwent arthroscopy a mean of 45 days ± 31 and 45 days ± 22 after MRI, respectively. Intermethod agreements were good at 1.5 T (κ >0.71 [95% CI: 0.56, 0.83]) and very good at 3.0 T (κ >0.85 [95% CI: 0.69, 0.96]). The diagnostic performances of corresponding 5-minute and 10-minute MRI protocols were similar for 1.5 T, with areas under the receiver operating characteristic curve (AUCs) greater than 0.78 (95% CI: 0.71, 0.84) (P > .32), and 3.0 T, with AUCs greater than 0.83 (95% CI: 0.78, 0.88) (P > .32). Conclusion Comparisons of 5-minute five-sequence simultaneous multislice- and parallel imaging (PI)-accelerated and 10-minute five-sequence PI-accelerated turbo spin-echo MRI of the knee suggest similar performances at 1.5 and 3.0 T. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Subhas in this issue.

Routine clinical knee MR reports: comparison of diagnostic performance at 1.5 T and 3.0 T for assessment of the articular cartilage

OBJECTIVE

Accurate assessment of knee articular cartilage is clinically important. Although 3.0 Tesla (T) MRI is reported to offer improved diagnostic performance, literature regarding the clinical impact of MRI field strength is lacking. The purpose of this study is to compare the diagnostic performance of clinical MRI reports for assessment of cartilage at 1.5 and 3.0 T in comparison to arthroscopy.

MATERIALS AND METHODS

This IRB-approved retrospective study consisted of 300 consecutive knees in 297 patients who had routine clinical MRI and arthroscopy. Descriptions of cartilage from MRI reports of 165 knees at 1.5 T and 135 at 3.0 T were compared with arthroscopy. The sensitivity, specificity, percent of articular surfaces graded concordantly, and percent of articular surfaces graded within one grade of the arthroscopic grading were calculated for each articular surface at 1.5 and 3.0 T. Agreement between MRI and arthroscopy was calculated with the weighted-kappa statistic. Significance testing was performed utilizing the z-test after bootstrapping to obtain the standard error.

RESULTS AND CONCLUSIONS

The sensitivity, specificity, percent of articular surfaces graded concordantly, and percent of articular surfaces graded within one grade were 61.4%, 82.7%, 62.2%, and 77.5% at 1.5 T and 61.8%, 80.6%, 59.5%, and 75.6% at 3.0 T, respectively. The weighted kappa statistic was 0.56 at 1.5 T and 0.55 at 3.0 T. There was no statistically significant difference in any of these parameters between 1.5 and 3.0 T. Factors potentially contributing to the lack of diagnostic advantage of 3.0 T MRI are discussed.

A new MRI grading system for chondromalacia patellae

Background Chondromalacia patellae is a very common disorder. Although magnetic resonance imaging (MRI) is widely used to investigate patellar cartilage lesions, there is no descriptive MRI-based grading system for chondromalacia patellae. Purpose To propose a new MRI grading system for chondromalacia patellae with corresponding high resolution images which might be useful in precisely reporting and comparing knee examinations in routine daily practice and used in predicting natural course and clinical outcome of the patellar cartilage lesions. Material and Methods High resolution fat-saturated proton density (FS PD) images in the axial plane with corresponding T2 mapping images were reviewed. A detailed MRI grading system covering the deficiencies of the existing gradings has been set and presented on these images. Two experienced observers blinded to clinical data examined 44 knee MR images and evaluated patellar cartilage changes according to the proposed grading system. Inter- and intra-rater validity testing using kappa statistics were calculated. Results A descriptive and detailed grading system with corresponding FS PD and T2 mapping images has been presented. Inter-rater agreement was 0.80 (95% confidence interval [CI], 0.71-0.89). Intra-rater agreements were 0.83 (95% CI, 0.74-0.91) for observer A and 0.79 (95% CI, 0.70-0.88) for observer B (k-values). Conclusion We present a new MRI grading system for chondromalacia patellae with corresponding images and good inter- and intra-rater agreement which might be useful in reporting and comparing knee MRI examinations in daily practice and may also have the potential for using more precisely predicting prognosis and clinical outcome of the patients.

Magnetic resonance imaging is the preferred method to assess treatment-related skeletal changes in children with brain tumors

PURPOSE

To evaluate the growing skeleton for potential altered skeletalgenesis associated with antiangiogenesis therapy.

PATIENTS AND METHODS

Knee radiographs and magnetic resonance imaging (MRI) were prospectively obtained on patients enrolled on two consecutive clinical trials using vandetanib, a potent oral (VEGF receptor 2) VEGFR-2 inhibitor alone or combined with dasatinib, a multiple tyrosine kinase inhibitor, in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

RESULTS

Fifty-nine patients (32 females) underwent 119 MRIs; 51 patients underwent 89 radiographs of the knees. The median age at enrollment was 6.2 years (range, 2.4-17.6 years). The dose of vandetanib ranged from 50 to 145 mg/m(2) /day. The median treatment duration was 205 days. Only two patients have not experienced disease progression after 18 and 60 months from diagnosis. MRI identified clinically significant premature physeal fusion in both knees of one patient, focal physeal thickening in one, osteonecrosis in eight patients (present at enrollment in one), and bony spicules crossing the physis in two patients (bilateral in one). MRI follow-up period averaged 5.3 months (range, 0-25.5 months; median, 3.5 months). Radiographs delineated normally fused physes in two patients but no cases of premature physeal fusion, osteonecrosis or bony spicules.

CONCLUSIONS

As MRI provided greater information than radiographs, and thus would be a more sensitive test to assess skeletalgenesis in pediatric patients.

Diagnostic performance of 3D SPACE for comprehensive knee joint assessment at 3 T

Objective

To assess the diagnostic performance of 3D sampling perfection with application-optimised contrasts using variable flip-angle evolution (SPACE) turbo spin-echo (TSE) sequences compared to 2D TSE for comprehensive knee assessment at 3 T.

Methods

From January to July 2011, isotropic 3D SPACE was added to a 2D knee protocol at 3 T. Forty patients underwent subsequent arthroscopy. Three readers independently assessed MR images for meniscus, anterior cruciate ligament (ACL) and cartilage lesions. Readers 1 and 2 evaluated 3D and 2D data at separate sittings; reader 3 interpreted the complete exam including 3D and 2D sequences. Accuracies were calculated using arthroscopy as reference standard. McNemar’s test (p < 0.05) was used to compare 3D and 2D techniques.

Results

The highest diagnostic yield was obtained by reader 3 (accuracies ≥88 %). For the medial meniscus, readers performed better with the 2D technique than with 3D SPACE (accuracies 85–88 % vs. 78–80 %, respectively) (p > 0.05). For the lateral meniscus and ACL, 3D and 2D techniques had similar performance (accuracies ≥93 %). For cartilage lesions, 3D SPACE had significantly lower specificity (p = 0.0156) than the 2D protocol for one reader.

Conclusion

The conventional 2D TSE acquisition is more reliable than 3D SPACE for comprehensive assessment of the knee at 3.0 T.

Main Messages

• 3D SPACE is a valuable component of a knee MR protocol at 3 T.

• 3D SPACE cannot be used as a single sequence in the MR evaluation of the knee at 3 T.

• Knee MR protocols at 3 T should include both 2D and 3D TSE sequences.

The paediatric wrist revisited--findings of bony depressions in healthy children on radiographs compared to MRI

BACKGROUND

The presence of erosions is used for diagnosis and monitoring of disease activity in juvenile idiopathic arthritis (JIA). Assessment of carpal bone erosions in children is challenging due to lack of normal references.

OBJECTIVE

To define normal appearances of bony depressions in the wrist on radiographs and MRI.

MATERIALS AND METHODS

MRI and radiography of the wrist were performed in 88 healthy children, 5-15 years of age. We assessed the number of bony depressions within the carpals/proximal metacarpals on both modalities, separately and combined.

RESULTS

A total of 75 carpal depressions were identified on radiography compared to 715 on MRI. The number of bony depressions identified radiographically showed no statistically significant difference across age-groups. Within the metacarpals, there was no significant difference between bony depressions identified by MRI or radiography, except at the bases of the second metacarpal.

CONCLUSION

Bony depressions that resemble erosions are normal findings in the wrist in children. MRI identifies more depressions than radiographs in the carpus. Some bony depressions occur at typical locations and should be accounted for when assessing the wrist in JIA to avoid overstaging.