Publications by authors named "Pieter Van Dyck"

31 Publications

Suture tape augmentation ACL repair, stable knee, and favorable PROMs, but a re-rupture rate of 11% within 2 years.

Knee Surg Sports Traumatol Arthrosc 2021 Jan 2. Epub 2021 Jan 2.

Antwerp University Hospital, Orthopaedics, Drie Eikenstraat 655, 2650, Edegem, Belgium.

Purpose: The aim of this study is to investigate clinical and magnetic resonance imaging (MRI) outcomes after anterior cruciate ligament (ACL) repair using the suture tape augmentation (STA) technique.

Methods: This prospective interventional case series included 35 patients who underwent STA ACL repair and were all followed up for 2 years. The ACL rupture was between 4 and 12 weeks old and per-operatively confirmed repairable. The International Knee Documentation Committee (IKDC), and Lysholm and Tegner scores were collected together with return to work (RTW), return to sport (RTS), re-rupture, and re-intervention rate. Lachman testing was performed and ACL healing was evaluated on MRI using a grading scale based on the ACL's morphology and signal intensity with grade 1 representing good ACL healing and grade 3 representing poor ACL healing.

Results: The number of patients who returned to their pre-rupture level for IKDC, Lysholm, and Tegner scores at 2 years of follow-up are 17/26 (65.4%), 13/25 (52.0%), and 18/27 (66.7%) patients, respectively. Median RTW and RTS periods were 5.5 weeks (range 0-32 weeks) and 6 months (range 2-22 months), respectively. The Lachman side-to-side difference decreased significantly (P < 0.001) to less than 3 mm after surgery and remained stable. Four patients [11.4%, 95% CI (3.2, 26.7)] suffered from a re-rupture and three other patients [8.6%, 95% CI (1.8, 23.1)] needed a re-intervention for another reason than re-rupture. MRI follow-up of 31 patients showed overall grade 1 ACL healing in 14 (45.2%) patients, grade 2 ACL healing in 11 (35.5%) patients, and grade 3 ACL healing in 6 (19.4%) patients. A higher risk of re-rupture was associated with grade 3 ACL healing at 6 months post-operatively and a pre-operative Tegner score of  ≥  7.

Conclusion: This study shows that treatment of the acute, repairable ACL with the STA technique leads to a stable knee and favorable patient-reported outcome measures (PROMs). However, the re-rupture rate of 11.4% within the 2-year follow-up is a concern.

Level Of Evidence: IV.
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http://dx.doi.org/10.1007/s00167-020-06399-2DOI Listing
January 2021

Diffusion tensor imaging of the anterior cruciate ligament graft following reconstruction: a longitudinal study.

Eur Radiol 2020 Dec 14;30(12):6673-6684. Epub 2020 Jul 14.

Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.

Objective: To longitudinally monitor remodeling of human autograft following anterior cruciate ligament (ACL) reconstruction with DTI.

Methods: Twenty-eight patients underwent DTI follow-up at 3, 8, and 14 months after clinically successful ACL reconstruction with tendon autograft. Among these, 18 patients had a concomitant lateral extra-articular procedure (LET). DTI data from 7 healthy volunteers was also obtained. Diffusion parameters (fractional anisotropy, FA; mean diffusivity, MD; axial diffusivity, AD; and radial diffusivity, RD) were evaluated within the fiber tractography volumes of the ACL graft and posterior cruciate ligament (PCL) in all patients. Data were analyzed using a linear mixed-effects model with post hoc testing using Bonferroni-Holm correction for multiple testing. The effect of additional LET was studied.

Results: The ACL graft showed a significant decrease of FA over time (F = 4.00, p = 0.025), while the diffusivities did not significantly change over time. For PCL there were no significant DTI changes over time. A different evolution over time between patients with and without LET was noted for all diffusivity values of the ACL graft with reduced AD values in patients with LET at 8 months postoperatively (p = 0.048; adjusted p = 0.387). DTI metrics of the ACL graft differed largely from both native ACL and tendon at 14 months postoperatively.

Conclusion: Our study has shown the potential of DTI to longitudinally monitor the remodeling process in human ACL reconstruction. DTI analysis indicates that graft remodeling is incomplete at 14 months postoperatively.

Key Points: • DTI can be used to longitudinally monitor the remodeling process in human ACL reconstruction. • DTI analysis indicates that autograft remodeling is incomplete at 14 months postoperatively. • DTI may be helpful for evaluating new ACL treatments.
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http://dx.doi.org/10.1007/s00330-020-07051-wDOI Listing
December 2020

Harmonization of Brain Diffusion MRI: Concepts and Methods.

Front Neurosci 2020 6;14:396. Epub 2020 May 6.

imec-Vision Lab, University of Antwerp, Antwerp, Belgium.

MRI diffusion data suffers from significant inter- and intra-site variability, which hinders multi-site and/or longitudinal diffusion studies. This variability may arise from a range of factors, such as hardware, reconstruction algorithms and acquisition settings. To allow a reliable comparison and joint analysis of diffusion data across sites and over time, there is a clear need for robust data harmonization methods. This review article provides a comprehensive overview of diffusion data harmonization concepts and methods, and their limitations. Overall, the methods for the harmonization of multi-site diffusion images can be categorized in two main groups: diffusion parametric map harmonization (DPMH) and diffusion weighted image harmonization (DWIH). Whereas DPMH harmonizes the diffusion parametric maps (e.g., FA, MD, and MK), DWIH harmonizes the diffusion-weighted images. Defining a gold standard harmonization technique for dMRI data is still an ongoing challenge. Nevertheless, in this paper we provide two classification tools, namely a feature table and a flowchart, which aim to guide the readers in selecting an appropriate harmonization method for their study.
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http://dx.doi.org/10.3389/fnins.2020.00396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7218137PMC
May 2020

Super-Resolution Magnetic Resonance Imaging of the Knee Using 2-Dimensional Turbo Spin Echo Imaging.

Invest Radiol 2020 08;55(8):481-493

imec-Vision Lab, Department of Physics, University of Antwerp, Wilrijk, Belgium.

Objectives: The purpose of this study was to assess the technical feasibility of 3-dimensional (3D) super-resolution reconstruction (SRR) of 2D turbo spin echo (TSE) knee magnetic resonance imaging (MRI) and to compare its image quality with conventional 3D TSE sampling perfection with application optimized contrast using different flip angle evolutions (SPACE) MRI.

Materials And Methods: Super-resolution reconstruction 2D TSE MRI and 3D TSE SPACE images were acquired from a phantom and from the knee of 22 subjects (8 healthy volunteers and 14 patients) using a clinical 3-T scanner. For SRR, 7 anisotropic 2D TSE stacks (voxel size, 0.5 × 0.5 × 2.0 mm; scan time per stack, 1 minute 55 seconds; total scan time, 13 minutes 25 seconds) were acquired with the slice stack rotated around the phase-encoding axis. Super-resolution reconstruction was performed at an isotropic high-resolution grid with a voxel size of 0.5 × 0.5 × 0.5 mm. Direct isotropic 3D image acquisition was performed with the conventional SPACE sequence (voxel size, 0.5 × 0.5 × 0.5 mm; scan time, 12 minutes 42 seconds). For quantitative evaluation, perceptual blur metrics and edge response functions were obtained in the phantom image, and signal-to-noise and contrast-to-noise ratios were measured in the images from the healthy volunteers. Images were qualitatively evaluated by 2 independent radiologists in terms of overall image quality, edge blurring, anatomic visibility, and diagnostic confidence to assess normal and abnormal knee structures. Nonparametric statistical analysis was performed, and significance was defined for P values less than 0.05.

Results: In the phantom, perceptual blur metrics and edge response functions demonstrated a clear improvement in spatial resolution for SRR compared with conventional 3D SPACE. In healthy subjects, signal-to-noise and contrast-to-noise ratios in clinically relevant structures were not significantly different between SRR and 3D SPACE. Super-resolution reconstruction provided better overall image quality and less edge blurring than conventional 3D SPACE, yet the perceived image contrast was better for 3D SPACE. Super-resolution reconstruction received significantly better visibility scores for the menisci, whereas the visibility of cartilage was significantly higher for 3D SPACE. Ligaments had high visibility on both SRR and 3D SPACE images. The diagnostic confidence for assessing menisci was significantly higher for SRR than for conventional 3D SPACE, whereas there were no significant differences between SRR and 3D SPACE for cartilage and ligaments. The interreader agreement for assessing menisci was substantial with 3D SPACE and almost perfect with SRR, and the agreement for assessing cartilage was almost perfect with 3D SPACE and moderate with SRR.

Conclusions: We demonstrate the technical feasibility of SRR for high-resolution isotropic knee MRI. Our SRR results show superior image quality in terms of edge blurring, but lower image contrast and fluid brightness when compared with conventional 3D SPACE acquisitions. Further contrast optimization and shortening of the acquisition time with state-of-the-art acceleration techniques are necessary for future clinical validation of SRR knee MRI.
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http://dx.doi.org/10.1097/RLI.0000000000000676DOI Listing
August 2020

Diffusion tensor imaging of the anterior cruciate ligament following primary repair with internal bracing: A longitudinal study.

J Orthop Res 2021 Jun 15;39(6):1318-1330. Epub 2020 Apr 15.

Icometrix, Leuven, Belgium.

Diffusion tensor imaging (DTI) provides information about tissue microstructure and its degree of organization by quantifying water diffusion. We aimed to monitor longitudinal changes in DTI parameters (fractional isotropy, FA; mean diffusivity, MD; axial diffusivity, AD; radial diffusivity, RD) of the anterior cruciate ligament (ACL) following primary repair with internal bracing (IBLA). Fourteen patients undergoing IBLA were enrolled prospectively and scheduled for clinical follow-up, including instrumented laxity testing, and DTI at 3, 6, 12, and 24 months postoperatively. DTI was also performed in seven healthy subjects. Fiber tractography was used for 3D segmentation of the whole ACL volume, from which median DTI parameters were calculated. The posterior cruciate ligament (PCL) served as a control. Longitudinal DTI changes were assessed using a linear mixed model, and repeated measures correlations were calculated between DTI parameters and clinical laxity tests. At follow-up, thirteen patients had a stable knee and one patient sustained an ACL rerupture after 12 months postoperatively. The ACL repair showed a significant decrease of FA within the first 12 months after surgery, followed by stable FA values thereafter, while ACL diffusivities decreased over time returning towards normal values at 24 months postoperatively. For PCL there were no significant DTI changes over time. There was a significant correlation between ACL FA and laxity tests (r = -0.42, P = .017). This study has shown the potential of DTI to longitudinally monitor diffusion changes in the ACL following IBLA. The DTI findings suggest that healing of the ACL repair is incomplete at 24 months postoperatively.
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http://dx.doi.org/10.1002/jor.24684DOI Listing
June 2021

Tips and Tricks to Optimize Surgical Outcomes After ACL Repair Using Dynamic Intraligamentary Stabilization.

Surg Technol Int 2020 May;36:309-316

Department of Radiology, Antwerp University, Hospital and University of Antwerp, Edegem, Belgium.

Purpose: This paper describes technical difficulties and outcomes for the first 15 patients treated with Dynamic Intraligamentary Stabilization (DIS) for anterior cruciate ligament (ACL) repair.

Methods: The first 15 patients treated with DIS were included. To optimize the inclusion process, a new pre-operative pathway was developed. All intra-operative technical problems were recorded. During the 2-year follow-up period, patient-related outcome measures, return to work, anterior-posterior knee laxity using a Rolimeter and ACL healing as revealed by MRI follow-up scans were recorded.

Results: During 11 DIS procedures, 15 technical problems were encountered. Six were surgeon-related and 9 were material-related. All problems were resolved intra-operatively. Repeat surgery was performed in 4 patients due to arthrofibrosis and in 1 due to a cyclops lesion. The DIS implant was removed in all 5 patients. According to the Tegner score, 7 of 10 (70%) patients returned to the pre-injury level of sporting activity within 6 months. The mean return to work time was 5.4 (SD 3.6) weeks. On MRI, 10 patients showed normal ACL healing (Grade 1) and 3 showed a high repair signal intensity (Grade 2). Although 2 patients showed no signs of ACL healing on MRI (Grade 3), no instability was reported or measured post-operatively or after the DIS implant was removed.

Conclusion: All intra-operative technical problems were resolved and did not lead to conversion to ACL reconstruction. We share tips and tricks that could assist surgeons who are just starting to use the DIS technique.
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May 2020

Study protocol: a single-blind, multi-center, randomized controlled trial comparing dynamic intraligamentary stabilization, internal brace ligament augmentation and reconstruction in individuals with an acute anterior cruciate ligament rupture: LIBRƎ study.

BMC Musculoskelet Disord 2019 Nov 18;20(1):547. Epub 2019 Nov 18.

Department of Radiology, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium.

Background: The current gold standard for the treatment of an anterior cruciate ligament (ACL) rupture is reconstruction with tendon graft. Recently, two surgical ACL repair techniques have been developed for treating an acute ACL rupture: Dynamic Intraligamentary Stabilization (DIS, Ligamys®) and Internal Brace Ligament Augmentation (IBLA, InternalBrace™). We will conduct a single-blind, multi-center, randomized controlled trial which compares DIS, IBLA and reconstruction for relative clinical efficacy and economic benefit.

Methods: Subjects, aged 18-50 years, with a proximal, primary and repairable ACL rupture will be included. DIS is preferably performed within 4 weeks post-rupture, IBLA within 12 weeks and reconstruction after 4 weeks post-rupture. Patients are included in study 1 if they present within 0-4 weeks post-rupture and surgery is feasible within 4 weeks post-rupture. Patients of study 1 will be randomized to either DIS or IBLA. Patients are included in study 2 if they present after 4 weeks post-rupture and surgery is feasible between 5 and 12 weeks post-rupture. Patients of study 2 will be randomized to either IBLA or reconstruction. A total of 96 patients will be included, with 48 patients per study and 24 patients per study arm. Patients will be followed-up for 2 years. The primary outcome is change from baseline (pre-rupture) in International Knee Documentation Committee score to 6 months post-operatively. The main secondary outcomes are the EQ-5D-5 L, Tegner score, Lysholm score, Lachman test, isokinetic and proprioceptive measurements, magnetic resonance imaging outcome, return to work and sports, and re-rupture/failure rates. The statistical analysis will be based on the intention-to-treat principle. The economic impact of the surgery techniques will be evaluated by the cost-utility analysis. The LIBRƎ study is to be conducted between 2018 and 2022.

Discussion: This LIBRƎ study protocol is the first study to compare DIS, IBLA and ACL reconstruction for relative clinical efficacy and economic benefit. The outcomes of this study will provide data which could aid orthopaedic surgeons to choose between the different treatment options for the surgical treatment of an acute ACL rupture.

Trial Registration: This study is registered at ClinicalTrials.gov; NCT03441295. Date registered 13.02.2018.
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http://dx.doi.org/10.1186/s12891-019-2926-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6862787PMC
November 2019

Assessment of Anterior Cruciate Ligament Graft Maturity With Conventional Magnetic Resonance Imaging: A Systematic Literature Review.

Orthop J Sports Med 2019 Jun 3;7(6):2325967119849012. Epub 2019 Jun 3.

Imec/Vision Lab, Department of Physics, University of Antwerp, Wilrijk, Belgium.

Background: Magnetic resonance imaging (MRI) signal intensity (SI) measurements are being used increasingly in both clinical and research studies to assess the maturity of anterior cruciate ligament (ACL) grafts in humans. However, SI in conventional MRI with weighted images is a nonquantitative measure dependent on hardware and software.

Purpose: To conduct a systematic review of studies that have used MRI SI as a proxy for ACL graft maturity and to identify potential confounding factors in assessing the ACL graft in conventional MRI studies.

Study Design: Systematic review; Level of evidence, 4.

Methods: A systematic review was conducted by searching the MEDLINE/PubMed, Scopus, and Cochrane Library electronic databases according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify studies that examined the healing of the intra-articular portion of the ACL graft by assessing SI on MRIs.

Results: A total of 34 studies were selected for inclusion in this systematic review. The MRI acquisition techniques and methods to evaluate the ACL graft SI differed greatly across the studies. No agreement was found regarding the time frames of SI changes in MRI reflecting normal healing of the ACL tendon graft, and the graft SI and clinical outcomes after ACL reconstruction were found to be poorly correlated.

Conclusion: The MRI acquisition and evaluation methods used to assess ACL grafts are very heterogeneous, impeding comparisons of SI between successive scans and between independent studies. Therefore, quantitative MRI-based biomarkers of ACL graft healing are greatly needed to guide the appropriate time of returning to sports after ACL reconstruction.
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http://dx.doi.org/10.1177/2325967119849012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6547178PMC
June 2019

Primary Posterior Cruciate Ligament Repair With The Novel Suture Tape Augmentation Technique.

Surg Technol Int 2019 May;34:469-475

Department of Orthopaedic Surgery, Antwerp University Hospital, Edegem, Belgium.

Background: A posterior cruciate ligament (PCL) rupture is less common than an anterior cruciate ligament (ACL) rupture. PCL reconstruction remains controversial with variable outcomes and problems. The encouraging results of the novel ACL repair techniques led to renewed interest in PCL repair. Primary arthroscopic PCL repair has been rarely discussed and literature is scarce. To the best of our knowledge, no PCL repair patient outcome has been reported with one of the novel PCL repair techniques. We present the first case report of two patients who have been treated with the novel PCL repair technique, the suture tape augmentation technique.

Case Description: Two patients who underwent primary PCL repair after an acute PCL rupture with a two-year follow up are presented. Patients were evaluated according to the Lysholm scale, the International Knee Documentation Committee (IKDC), and the Tegner activity scale. Follow up also included objective physical examinations-knee function and posterior drawer test using a rolimeter-and magnetic resonance imaging (MRI). Physical examinations were performed at three months, six months, one year, and two years after surgery.

Outcomes: At two-year follow up, both patients had a full range of motion and experienced no pain, nor swelling. IKDC scores were 83% (good) and 100% (excellent), Lysholm scores were 99 and 100 two years after surgery. At three months postoperative, the Tegner activity scale equaled the preinjury Tegner activity scale. One patient was horseback riding within three months. There were some increased posterior translation differences after two years-+2 and +3mm-compared with six weeks postoperative. MRI showed a healed PCL in both cases.

Discussion: PCL repair could be a promising treatment option for acute PCL ruptures. Advantages of this technique are the retaining of the natural proprioceptive capacities due to preserving native PCL fibers, the surgical technique is less invasive compared to a reconstruction, and no donor graft morbidity is expected as no graft is needed.

Conclusion: In these two cases, good subjective and objective results are demonstrated after PCL repair using the novel suture tape augmentation technique. MRI confirmed the healing of the PCL. Although this is a small case series, as PCL ruptures are less common compared to ACL ruptures, it is a stepping-stone for further PCL repair research.
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May 2019

Assessment of Anterolateral Complex Injuries by Magnetic Resonance Imaging in Patients With Acute Rupture of the Anterior Cruciate Ligament.

Arthroscopy 2019 02 3;35(2):521-527. Epub 2019 Jan 3.

Department of Orthopedics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium.

Purpose: To assess anterolateral complex (ALC) injuries in patients with acute anterior cruciate ligament (ACL) rupture on magnetic resonance imaging (MRI).

Methods: Patients with acute ACL rupture who underwent ACL surgery between 2015 and 2017 and underwent MRI within 6 weeks of the initial trauma were included. Two radiologists assessed magnetic resonance images retrospectively for the status of the ALC, including the iliotibial band (ITB), Kaplan fibers, and anterolateral ligament (ALL), as follows: grade 0, normal; grade 1, periligamentous edema; grade 2, partial tear; and grade 3, complete tear. The findings were analyzed using the Friedman test and weighted κ values.

Results: Sixty-nine MRI scans were reviewed. Of the 69 patients, 51% had associated injuries to the ITB (grade 1, n = 31; grade 2, n = 4), 33% had associated injuries to the Kaplan fibers (grade 1, n = 21; grade 2, n = 2), and 57% had associated injuries to the ALL (grade 1, n = 12; grade 2, n = 22; grade 3, n = 5). We found a significant difference in the frequency and grading between ITB, Kaplan fiber, and ALL injuries (P ≤ .032). Inter-reader agreement for assessing the ALC on MRI was almost perfect (κ ≥ 0.922).

Conclusions: On the basis of MRI analysis, ALL injuries were found with varying degrees of severity and intensity with noted injuries to associated surrounding fibers in patients with acute ACL rupture.

Level Of Evidence: Level IV, case series.
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http://dx.doi.org/10.1016/j.arthro.2018.08.032DOI Listing
February 2019

Pitfalls in MR imaging of acute anterior cruciate ligament injuries.

Authors:
Pieter Van Dyck

Knee Surg Sports Traumatol Arthrosc 2020 11 4;28(11):3622-3624. Epub 2017 Sep 4.

Department of Radiology, Antwerp University Hospital, University of Antwerp, Wilrijkstraat 10, 2650, Edegem, Antwerp, Belgium.

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http://dx.doi.org/10.1007/s00167-017-4701-9DOI Listing
November 2020

Diffusion tensor imaging of the anterior cruciate ligament graft.

J Magn Reson Imaging 2017 11 14;46(5):1423-1432. Epub 2017 Feb 14.

Imec/Vision Lab, Department of Physics, University of Antwerp, Wilrijk, Belgium.

Purpose: A great need exists for objective biomarkers to assess graft healing following ACL reconstruction to guide the time of return to sports. The purpose of this study was to evaluate the feasibility and reliability of diffusion tensor imaging (DTI) to delineate the anterior cruciate ligament (ACL) graft and to investigate its diffusion properties using a clinical 3T scanner.

Materials And Methods: DTI of the knee (b = 0, 400, and 800 s/mm , 10 diffusion directions, repeated 16 times for a total of 336 diffusion-weighted volumes) was performed at 3T in 17 patients between 3 and 7 months (mean, 4 months) following ACL reconstruction. Tractography was performed by two independent observers to delineate the ACL graft. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated within the graft. Interrater reliability was assessed using the intraclass correlation coefficient (ICC) and the scan-rescan reproducibility was evaluated based on the percentage coefficient of variance (%CV) across 20 repetition bootknife samples.

Results: In all subjects, tractography of the ACL graft was feasible. Quantitative evaluation of the diffusion properties of the ACL graft yielded the following mean ± SD values: FA = 0.23 ± 0.04; MD = 1.30 ± 0.11 × 10 mm /s; AD = 1.61 ± 0.12 × 10 mm /s, and RD = 1.15 ± 0.11 × 10 mm /s. Interrater reliability for the DTI parameters was excellent (ICC = 0.91-0.98). Mean %CVs for FA, MD, AD, and RD were 4.6%, 3.5%, 3.7%, and 4.4%, respectively.

Conclusion: We demonstrated the feasibility and reliability of DTI for the visualization and quantitative evaluation of the ACL graft at 3T.

Level Of Evidence: 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1423-1432.
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http://dx.doi.org/10.1002/jmri.25666DOI Listing
November 2017

Common Mistakes and Pitfalls in Magnetic Resonance Imaging of the Knee.

J Belg Soc Radiol 2016 Nov 19;100(1):99. Epub 2016 Nov 19.

UZ Antwerpen, BE.

This pictorial review presents an overview of common interpretation errors and pitfalls in magnetic resonance imaging (MRI) of the knee. Instead of being exhaustive, we will emphasize those pitfalls that are most commonly encountered by young residents or less experienced radiologists.
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http://dx.doi.org/10.5334/jbr-btr.1206DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6100447PMC
November 2016

Imaging of the Postoperative Anterior Cruciate Ligament: Emphasis on New Surgical and Imaging Methods.

Semin Musculoskelet Radiol 2016 Feb 14;20(1):33-42. Epub 2016 Apr 14.

Department of Radiology, Antwerp University Hospital and University of Antwerp, Edegem, Belgium.

The aim of anterior cruciate ligament (ACL) reconstruction is to restore normal function of the knee, but unfortunately abnormal kinematics and a predisposition to knee osteoarthritis occur in a significant percentage of patients. So there is an ongoing need to improve treatment options and long-term outcome of patients with a ruptured ACL. With the recent advancements in the field of ACL tissue engineering, the focus of treatment for ACL injuries is changing from resection and reconstruction toward repair and regeneration. Several new ACL repair methods were recently introduced as an alternative to traditional ACL reconstructive procedures. Radiologists must become familiar with these new surgical methods to interpret their appearance correctly on postoperative imaging studies. This article provides an overview of the latest advancements in ACL surgical methods and discusses the role of imaging to assess the postoperative ACL including both standard and advanced imaging methods.
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http://dx.doi.org/10.1055/s-0036-1579678DOI Listing
February 2016

The Anterolateral Ligament of the Knee: What the Radiologist Needs to Know.

Semin Musculoskelet Radiol 2016 Feb 14;20(1):26-32. Epub 2016 Apr 14.

Department of Radiology, Antwerp University Hospital and University of Antwerp, Edegem, Belgium.

The anterolateral ligament (ALL) was recently identified as a distinct component of the anterolateral capsule of the human knee joint with consistent origin and insertion sites. Biomechanical studies revealed that the current association between the pivot shift and an injured anterior cruciate ligament (ACL) should be loosened and that the rotational component of the pivot shift is significantly affected by the ALL. This may change the clinical approach toward ACL-injured patients presenting with anterolateral rotatory instability (ALRI), the most common instability pattern after ACL rupture. Radiologists should be aware of the importance of the ALL to ACL injuries. They should not overlook pathology of the anterolateral knee structures, including the ALL, when reviewing MR images of the ACL-deficient knee. In this article, the current knowledge regarding the anatomy, biomechanical function, and imaging appearance of the ALL of the knee is discussed with emphasis on the clinical implications of these findings.
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http://dx.doi.org/10.1055/s-0036-1579679DOI Listing
February 2016

Anterolateral ligament abnormalities in patients with acute anterior cruciate ligament rupture are associated with lateral meniscal and osseous injuries.

Eur Radiol 2016 Oct 8;26(10):3383-91. Epub 2016 Jan 8.

Department of Radiology, Antwerp University Hospital and University of Antwerp, Wilrijkstraat 10, B-2650, Edegem, Antwerp, Belgium.

Objective: To determine the frequency of anterolateral ligament (ALL) injury in patients with acute anterior cruciate ligament (ACL) rupture and to analyse its associated injury patterns.

Methods: Ninety patients with acute ACL rupture for which MRI was obtained within 8 weeks after the initial trauma were retrospectively identified. Two radiologists assessed the status of the ALL on MRI by consensus. The presence or absence of an ALL abnormality was compared with the existence of medial and lateral meniscal tears diagnosed during arthroscopy. Associated collateral ligament and osseous injuries were documented with MRI.

Results: Forty-one of 90 knees (46 %) demonstrated ALL abnormalities on MRI. Of 49 knees with intact ALL, 15 (31 %) had a torn lateral meniscus as compared to 25 torn lateral menisci in 41 knees (61 %) with abnormal ALL (p = 0.008). Collateral ligament (p ≤ 0.05) and osseous injuries (p = 0.0037) were more frequent and severe in ALL-injured as compared with ALL-intact knees.

Conclusion: ALL injuries are fairly common in patients with acute ACL rupture and are statistically significantly associated with lateral meniscal, collateral ligament and osseous injuries.

Key Points: • ALL injuries are fairly common in patients with acute ACL rupture. • ALL injuries are highly associated with lateral meniscal and osseous injuries. • MRI assessment of ACL-injured knees should include evaluation of the ALL.
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http://dx.doi.org/10.1007/s00330-015-4171-8DOI Listing
October 2016

Morphological MR imaging of the articular cartilage of the knee at 3 T-comparison of standard and novel 3D sequences.

Insights Imaging 2015 Jun 9;6(3):285-93. Epub 2015 Apr 9.

Department of Radiology, Antwerp University Hospital and University of Antwerp, Wilrijkstraat 10, 2650, Antwerp (Edegem), Belgium,

Objectives: This study sought to compare various 3D cartilage sequences and to evaluate the usefulness of ultrashort TE (UTE) imaging, a new technique to isolate signal from the osteochondral junction.

Methods: Twenty knees were examined at 3 T with 3D spoiled GRE (FLASH), double-echo steady-state (DESS), balanced SSFP, 3D turbo spin-echo (TSE), and a prototype UTE sequence. Two radiologists independently evaluated all images. Consensus readings of all sequences were the reference standard. Statistical analysis included Friedman and pairwise Wilcoxon tests. Retrospective analysis of UTE morphology of osteochondral tissue in normal and abnormal cartilage seen at conventional MR was also performed.

Results: Three-dimensional TSE was superior to other sequences for detecting cartilage lesions. FLASH and DESS performed best in the subjective quality analysis. On UTE images, normal cartilage exhibited a high-intensity linear signal near the osteochondral junction. Retrospective analysis revealed abnormal UTE morphology of the osteochondral junction in 50 % of cartilage lesions diagnosed at conventional MR.

Conclusions: Cartilage imaging of the knee at 3 T can be reliably performed using 3D TSE, showing high accuracy when compared to standard sequences. Although UTE depicts signal from the deep cartilage layer, further studies are needed to establish its role for assessment of cartilage.

Main Messages: • MRI is the best available imaging method for assessment of knee cartilage. • Cartilage imaging can be reliably performed using 3D TSE. • UTE cannot be used as a single sequence to assess cartilage.
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http://dx.doi.org/10.1007/s13244-015-0405-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4444789PMC
June 2015

Comparison of 1.5- and 3-T MR imaging for evaluating the articular cartilage of the knee.

Knee Surg Sports Traumatol Arthrosc 2014 Jun 9;22(6):1376-84. Epub 2013 Oct 9.

Department of Radiology, Antwerp University Hospital and University of Antwerp, Wilrijkstraat 10, Edegem, 2650, Antwerp, Belgium,

Purpose: The aim of this prospective study was to compare routine MRI scans of the knee at 1.5 and 3 T obtained in the same individuals in terms of their performance in the diagnosis of cartilage lesions.

Methods: One hundred patients underwent MRI of the knee at 1.5 and 3 T and subsequent knee arthroscopy. All MR examinations consisted of multiplanar 2D turbo spin-echo sequences. Three radiologists independently graded all articular surfaces of the knee joint seen at MRI. With arthroscopy as the reference standard, the sensitivity, specificity, and accuracy of 1.5- and 3-T MRI for detecting cartilage lesions and the proportion of correctly graded cartilage lesions within the knee joint were determined and compared using resampling statistics.

Results: For all readers and surfaces combined, the respective sensitivity, specificity, and accuracy for detecting all grades of cartilage lesions in the knee joint using MRI were 60, 96, and 87% at 1.5 T and 69, 96, and 90% at 3 T. There was a statistically significant improvement in sensitivity (p < 0.05), but not specificity or accuracy (n.s.) for the detection of cartilage lesions at 3 T. There was also a statistically significant (p < 0.05) improvement in the proportion of correctly graded cartilage lesions at 3 T as compared to 1.5 T.

Conclusion: A 3-T MR protocol significantly improves diagnostic performance for the purpose of detecting cartilage lesions within the knee joint, when compared with a similar protocol performed at 1.5 T.

Level Of Evidence: III.
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http://dx.doi.org/10.1007/s00167-013-2704-8DOI Listing
June 2014

Prospective comparison of 1.5 and 3.0-T MRI for evaluating the knee menisci and ACL.

J Bone Joint Surg Am 2013 May;95(10):916-24

Departments of Radiology, Antwerp University Hospital and University of Antwerp, Wilrijkstraat 10, 2650 Antwerp (Edegem), Belgium.

Background: MRI (magnetic resonance imaging) is widely used to diagnose meniscal pathology and ACL (anterior cruciate ligament) tears. Because of the enhanced signal-to-noise ratio and improved image quality at higher field strength, knee MRI equipment is shifting from 1.5 to 3.0 T. To date, objective evidence of improved diagnostic ability at 3.0 T is lacking. The purpose of this prospective study was to assess the accuracy of 1.5 and 3.0-T MRI of the knee, in the same individuals, for diagnosing meniscal pathology and ACL tears, utilizing arthroscopy as the reference standard.

Methods: Two hundred patients underwent MRI of the knee at 1.5 and 3.0 T. All MRI examinations consisted of multiplanar turbo spin-echo sequences. One hundred patients underwent subsequent knee arthroscopy. Two blinded independent radiologists assessed all MRI studies to identify meniscal pathology and ACL tears. In patients with MRI results indicating the need for surgical treatment, the sensitivity and specificity of the 1.5 and 3.0-T protocols for detecting these lesions were determined, utilizing arthroscopy as the reference standard, and compared with use of the McNemar test. The kappa statistic for inter-reader agreement in the 200 patients was calculated.

Results: For medial meniscal tears, the mean sensitivity and specificity for the two readers were 93% and 90%, respectively, at 1.5 T and 96% and 88%, respectively, at 3.0 T. For lateral meniscal tears, the mean sensitivity and specificity were 77% and 99%, respectively, at 1.5 T and 82% and 98%, respectively, at 3.0 T. For ACL tears, the mean sensitivity and specificity were 78% and 100%, respectively, at 1.5 T and 80% and 100%, respectively, at 3.0 T. None of the values for either reader differed significantly between the 1.5 and 3.0-T MRI protocols. Inter-reader agreement was almost perfect to perfect (kappa = 0.82 to 1.00).

Conclusions: Routine use of a 3.0-T MRI protocol did not significantly improve accuracy for evaluating the knee menisci and ACL compared with a similar 1.5-T protocol.
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http://dx.doi.org/10.2106/JBJS.L.01195DOI Listing
May 2013

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

Insights Imaging 2012 Dec 26;3(6):603-10. Epub 2012 Oct 26.

Department of Radiology, University Hospital Antwerp, Wilrijkstraat 10, 2650, Edegem, Belgium,

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.
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http://dx.doi.org/10.1007/s13244-012-0197-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3505565PMC
December 2012

A comparison between histopathology and findings on magnetic resonance imaging of subcutaneous lipomatous soft-tissue tumors.

Insights Imaging 2011 Oct 24;2(5):599-607. Epub 2011 May 24.

OBJECTIVE: To retrospectively analyse the magnetic resonance (MR) findings of subcutaneous lipomatous soft-tissue tumours (SLSTT) in order to define a diagnostic and therapeutic strategy. METHODS: The MR findings of 46 SLSTT were registered for the following data: area, location within the subcutaneous compartment, dimensions, shape and delineation, signal intensity (SI) on different pulse sequences, signal homogeneity, degree and pattern of contrast enhancement. The MR findings, together with patients' age and gender, were compared with histopathological findings. RESULTS: Sixty-eight percent of the lipomas had a homogeneous T1-SI identical to the SI of subcutaneous fat. Heterogeneity in other lipomas was due to fat necrosis and small septa. Other lesions with homogeneous T1-SI identical to the SI of subcutaneous fat included lipoblastoma, lipomatosis and lipoma-like hibernoma. None of the liposarcomas were homogeneous and isointense to SI of subcutaneous fat on T1-weighted imaging (WI). Lipoma variants and liposarcomas showed overlapping MR characteristics. CONCLUSIONS: SLSTT with homogeneous T1-SI identical to the SI of subcutaneous fat are benign. If a SLSTT has other MR characteristics, differentiation based on MRI cannot be made and biopsy is needed. We used this finding in defining a diagnostic and therapeutic strategy for subcutaneous soft tissue tumours that are hyperintense on T1-WI.
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http://dx.doi.org/10.1007/s13244-011-0107-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259327PMC
October 2011

Pseudotumoural soft tissue lesions of the foot and ankle: a pictorial review.

Insights Imaging 2011 Aug 1;2(4):439-452. Epub 2011 May 1.

In the foot and ankle region, benign neoplasms and pseudotumoural soft tissue lesions are significantly more frequent than malignant tumours. The pseudotumoural lesions constitute a heterogeneous group, with highly varied aetiology and histopathology. This article reviews the imaging features of the most common pseudotumours of the soft tissues in the foot and ankle. Although the imaging characteristics of several of the lesions discussed are non-specific, combining them with lesion location and clinical features allows the radiologist to suggest a specific diagnosis in most cases.
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http://dx.doi.org/10.1007/s13244-011-0087-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259410PMC
August 2011

Pseudotumoural soft tissue lesions of the hand and wrist: a pictorial review.

Insights Imaging 2011 Jun 25;2(3):319-333. Epub 2011 Feb 25.

Mimickers of soft tissue tumours in the hand and wrist are more frequent than true neoplastic lesions. Pseudotumours belong to a large and heterogeneous group of disorders, varying from normal anatomical variants, cystic lesions, post-traumatic lesions, skin lesions, inflammatory and infectious lesions, non-neoplastic vascular lesions, metabolic disorders (crystal deposition disease and amyloidosis) and miscellaneous disorders. Although the imaging approach to pseudotumoural lesions is often very similar to the approach to "true" soft tissue tumoral counterparts, further management of these lesions is different. Biopsy should be performed only in doubtful cases, when the diagnosis is unclear. Therefore, the radiologist plays a pivotal role in the diagnosis of these lesions. Awareness of the normal anatomy and existence and common imaging presentation of these diseases, in combination with relevant clinical findings (clinical history, age, location and skin changes), enables the radiologist to make the correct diagnosis in most cases, thereby limiting the need for invasive procedures.
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http://dx.doi.org/10.1007/s13244-011-0076-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259322PMC
June 2011

Partial tear of the anterior cruciate ligament of the knee: injury patterns on MR imaging.

Knee Surg Sports Traumatol Arthrosc 2012 Feb 20;20(2):256-61. Epub 2011 Jul 20.

Department of Radiology, University Hospital Antwerp and University of Antwerp, Wilrijkstraat 10, 2650 Edegem, Belgium.

Purpose: To describe rupture patterns of partial anterior cruciate ligament (ACL) tears on magnetic resonance (MR) imaging.

Methods: MR images of 51 patients with a surgically confirmed partial ACL tear were retrospectively and independently interpreted by 2 experienced, blinded radiologists. Using previously described MR criteria, ACLs were categorized as follows: complete tear, partial tear, isolated anteromedial or posterolateral bundle tear, mucoid degeneration or normal ACL. MR interpretations were compared with the arthroscopic results as the standard of reference. Inter- and intraobserver agreements were determined using kappa (к) coefficients.

Results: On MR imaging, ACL injuries were categorized as complete tears (16-23%), partial tears (20-47%), mucoid degeneration (12-27%) or normal ACLs (18-23%). Isolated ACL bundle tears were diagnosed on MR in 6% of our patients. Accuracy of MR for the diagnosis of partial ACL tears was 25-53%. Interobserver agreement was moderate (к = 0.48-0.56). Intraobserver agreement was good (к = 0.72-0.76).

Conclusion: MR diagnosis of a partial ACL tear is difficult because various tear patterns may be seen. Many partial tears demonstrate MR features that are indistinguishable from complete ACL tear, mucoid ACL degeneration or normal ACL. An isolated ACL bundle tear is infrequently detected on MR images.
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http://dx.doi.org/10.1007/s00167-011-1617-7DOI Listing
February 2012

Experience with a frontal core biopsy device in soft tissue and bone lesions.

Skeletal Radiol 2012 Apr 12;41(4):447-58. Epub 2011 May 12.

Department of Radiology, University of Antwerp and Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium.

Objective: To assess the efficacy and cost of a new frontloading biopsy system, Spirotome® (system 1), in musculoskeletal lesions, and to compare the results with those obtained with commonly used biopsy devices.

Methods: System 1 was used in all soft tissue lesions (STL) and osteolytic bone lesions (OBL) of patients who presented at our department for CT-guided biopsy between January 2009 and June 2010. Accuracy and cost were compared to those of Bonopty® (system 2) and Tru-cut (system 3) procedures.

Results: The efficacy of system 1 was 85% in STL and 89% in OBL. The procedure was well tolerated and caused no complications. System 3 had an efficacy of 84% in STL and OBL combined. The efficacy of system 2 in OBL was 85%. The cost of single-use system 1 and system 2 was comparable, the cost of system 3 and multiuse system 1 compared to single-use system 1 was 25 and 7%, respectively.

Conclusions: The efficacy of system 1 in biopsy of STL and OBL was better than that of system 3. In OBL, the efficacy of system 1 was better than that of system 2. In STL at hazardous locations and small OBL with a thin cortical shell, system 1 offers the advantage of variable length and controlled loading. In these cases, single-use system 1 was cost-effective when compared to surgical biopsy. The cost per procedure of multiuse system 1 was lower than of system 3.
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http://dx.doi.org/10.1007/s00256-011-1191-6DOI Listing
April 2012

Stable or unstable tear of the anterior cruciate ligament of the knee: an MR diagnosis?

Skeletal Radiol 2012 Mar 19;41(3):273-80. Epub 2011 Apr 19.

Department of Radiology, University Hospital Antwerp and University of Antwerp, Wilrijkstraat 10, 2650, Edegem, Belgium.

Purpose: To determine the usefulness of magnetic resonance (MR) imaging to distinguish stable from unstable tears of the anterior cruciate ligament (ACL) of the knee.

Materials And Methods: MR images of 97 patients with surgically confirmed ACL tear were retrospectively reviewed. According to arthroscopic and clinical examination, these patients had 36 stable and 61 unstable (9 partial and 52 complete) ACL tears. MR images were interpreted by two blinded reviewers and scored with respect to previously reported primary and secondary MR signs of ACL injury. Based on a comprehensive assessment of all the MR findings, ACLs were categorized as being stable or unstable. MR accuracy was calculated considering only primary MR signs and considering both primary and secondary MR signs of ACL injury, separately. Accuracy of each individual primary and secondary MR sign was calculated.

Results: Considering only primary MR signs, sensitivity, specificity, and accuracy of MR were 77, 92, and 82%, respectively. Considering both primary and secondary MR signs, sensitivity, specificity, and accuracy of MR were 59, 81, and 67%, respectively. Of all MR signs, discontinuity and abnormal orientation had highest test accuracy (79 and 87%, respectively). Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL were only seen in unstable ACLs (specificity 100%), but these secondary findings had low sensitivity (23%). Bone contusion around the lateral knee compartment was seen in both unstable and stable ACLs (accuracy 64%).

Conclusion: Previously reported MR imaging signs do not allow accurate distinction between clinically stable and unstable ACL injuries. Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL, if present, are helpful signs in the diagnosis of an unstable tear. The presence of bone marrow edema around the lateral knee compartment is not predictive of ACL insufficiency.
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http://dx.doi.org/10.1007/s00256-011-1169-4DOI Listing
March 2012

Three tesla magnetic resonance imaging of the anterior cruciate ligament of the knee: can we differentiate complete from partial tears?

Skeletal Radiol 2011 Jun 8;40(6):701-7. Epub 2010 Oct 8.

Department of Radiology, University Hospital Antwerp and University of Antwerp, Wilrijkstraat 10, 2650, Antwerp (Edegem), Belgium.

Purpose: To determine the ability of 3.0T magnetic resonance (MR) imaging to identify partial tears of the anterior cruciate ligament (ACL) and to allow distinction of complete from partial ACL tears.

Materials And Methods: One hundred seventy-two patients were prospectively studied by 3.0T MR imaging and arthroscopy in our institution. MR images were interpreted in consensus by two experienced reviewers, and the ACL was diagnosed as being normal, partially torn, or completely torn. Diagnostic accuracy of 3.0T MR for the detection of both complete and partial tears of the ACL was calculated using arthroscopy as the standard of reference.

Results: There were 132 patients with an intact ACL, 17 had a partial, and 23 had a complete tear of the ACL seen at arthroscopy. Sensitivity, specificity, and accuracy of 3.0T MR for complete ACL tears were 83, 99, and 97%, respectively, and, for partial ACL tears, 77, 97, and 95%, respectively. Five of 40 ACL lesions (13%) could not correctly be identified as complete or partial ACL tears.

Conclusion: MR imaging at 3.0T represents a highly accurate method for identifying tears of the ACL. However, differentiation between complete and partial ACL tears and identification of partial tears of this ligament remains difficult, even at 3.0T.
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http://dx.doi.org/10.1007/s00256-010-1044-8DOI Listing
June 2011

Three-Tesla magnetic resonance imaging of the meniscus of the knee: What about equivocal errors?

Acta Radiol 2010 Apr;51(3):296-301

Department of Radiology, University Hospital Antwerp and University of Antwerp, Antwerp (Edegem), Belgium.

Background: The significance of borderline magnetic resonance (MR) findings that are equivocal for a tear of the knee meniscus remains uncertain. Given their higher signal-to-noise ratio (SNR) and greater spatial resolution, these equivocal meniscal tears could be expected to be less frequent using a 3.0T MR system.

Purpose: To investigate the prevalence of equivocal meniscal tears using 3.0T MR, and to study their impact on MR accuracy compared with arthroscopy in the detection of meniscal tears.

Material And Methods: The medical records of 100 patients who underwent 3.0T MR imaging and subsequent arthroscopy of the knee were retrospectively reviewed. Two observers interpreted MR images in consensus, and menisci were diagnosed as torn (abnormality on two or more images), equivocal for a tear (abnormality on one image), or intact, using arthroscopy as the standard of reference. The prevalence of equivocal meniscal tears was assessed, and MR accuracy was calculated as follows: first, considering both torn menisci and equivocal diagnoses as positive for a tear; and second, considering only torn menisci as positive for a tear.

Results: Evidence of meniscal tears on MR images was equivocal in 12 medial (12%) and three lateral (3%) menisci. Of these equivocal MR diagnoses, tears were found at arthroscopy in eight medial and one lateral meniscus. In our study, the specificity and positive predictive value increased for both the medial and lateral meniscus when only menisci with two or more abnormal images were considered to be torn: from 80% and 89% to 91% and 94% for the medial meniscus, and from 91% and 73% to 93% and 78% for the lateral meniscus, respectively.

Conclusion: Subtle findings that are equivocal for a tear of the knee meniscus still make MR diagnosis difficult, even at 3.0T. We recommend that radiologists should rather be descriptive in reporting subtle or equivocal MR findings, alerting the clinician of possible meniscal tear.
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http://dx.doi.org/10.3109/02841850903515403DOI Listing
April 2010

Chronic exertional compartment syndrome of the forearm in motocross racers: findings on MRI.

Skeletal Radiol 2009 Dec 17;38(12):1153-61. Epub 2009 Jul 17.

Department of Radiology, Antwerp University Hospital, Antwerp, Belgium.

Introduction: The purpose of this prospective study was to demonstrate the findings of MRI in motocross racers with chronic exertional compartment syndrome (CECS) of the forearm.

Materials And Methods: Racers with proven CECS and without CECS and male individuals not involved in strenuous activities with the forearm were included. Signal intensity (SI) and signal-to-noise ratio (SNR) obtained before and after exercise were compared (D-SNR).

Results: Magnetic resonance imaging after exercise showed an increase in SI and SNR in the muscles on T2-WI. The SI increase was obvious in the flexor digitorum superficialis (FDS) and profundus (FDP) in all CECS patients. In addition, a minor SI and SNR increase in the extensor carpi radialis longus (ECRL) was noted. In the non-symptomatic group of motocross racers, there was only a minor increase in SI and the SNR, which was similar in the FDP and ECRL muscles. In the untrained individuals a remarkable increase in the SI and SNR of the FDS/FDP-ECRL was noted. This increased SI and SNR was not present in the majority of non-symptomatic racers.

Conclusion: Post-exertional MRI produces significant findings in CECS of the forearm. The motocross racers without post-exertional oedema in the FDP/FDS had no CECS.
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http://dx.doi.org/10.1007/s00256-009-0746-2DOI Listing
December 2009

Sports-related acute and chronic avulsion injuries in children and adolescents with special emphasis on tennis.

Br J Sports Med 2007 Nov 22;41(11):827-31. Epub 2007 Jun 22.

Department of Radiology, AZ St-Maarten, campus Duffel, Rooienberg, Duffel, Belgium.

Acute and chronic sports-related muscle and tendon injuries are not infrequent in youngsters. In particular, the physis is prone to trauma as it constitutes the weakest part of the immature skeleton. The type of sports activity determines the location of the lesion. Most commonly, apophyses of the hip and pelvis are subject to avulsion. The purpose of this paper is to give a short overview of the pathogenesis, location, prevalence and imaging characteristics of acute and chronic avulsion injuries in the immature skeleton, with special emphasis on tennis-related injuries. Tennis-related injuries particularly involve apophyses of the ischial tuberosity, the anterior inferior or superior iliac spine and the iliac crest.
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http://dx.doi.org/10.1136/bjsm.2007.036921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2465275PMC
November 2007
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