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Local-area cartilage segmentation (LACS) software was developed to segment medial femur (MF) cartilage on magnetic resonance imaging (MRI). Our objectives were 1) to extend LACS to the lateral femur (LF), medial tibia (MT), and lateral tibia (LT), 2) to compare LACS to an established manual segmentation method, and 3) to visualize cartilage responsiveness over each cartilage plate.Osteoarthritis Initiative participants with symptomatic knee osteoarthritis (OA) were selected, including knees selected at random (n = 40) and knees identified with loss of cartilage based on manual segmentation (Chondrometrics GmbH), an enriched sample of 126 knees. LACS was used to segment cartilage in the MF, LF, MT, and LT on sagittal 3D double-echo steady-state MRI scans at baseline and at 2-year follow-up. We compared LACS and Chondrometrics average thickness measures by estimating the correlation in each cartilage plate and estimating the standardized response mean (SRM) for 2-year cartilage change. We illustrated cartilage loss topographically with SRM heatmaps.The estimated correlation between LACS and Chondrometrics measures was r = 0.91 (95% confidence interval [95% CI] 0.86, 0.94) for LF, r = 0.93 (95% CI 0.89, 0.95) for MF, r = 0.97 (95% CI 0.96, 0.98) for LT, and r = 0.87 (95% CI 0.81, 0.91) for MT. Estimated SRMs for LACS and Chondrometrics measures were similar in the random sample, and SRM heatmaps identified subregions of LACS-measured cartilage loss.LACS cartilage thickness measurement in the MF and LF and tibia correlated well with established manual segmentation-based measurement, with similar responsiveness to change, among knees with symptomatic knee OA. LACS measurement of cartilage plate topography enables spatiotemporal analysis of cartilage loss in future knee OA studies.

Purpose Trochlear dysplasia (TD) is a developmental condition and classified in to four types by Dejour. Patients with TD are more likely to have anterior cruciate ligament (ACL) injury. Increased ACL loading caused by TD may result in ACL-mucoid degeneration (MD). The purpose of this study was to evaluate the presence of ACL-MD in patients with TD and investigate whether there was a correlation between ACL-MD and TD grade and tibial tuberosity-trochlear groove (TT-TG) distance. Materials and Methods Knee MR examinations of one hundred five patients with TD were included in this study. TD was graded according to Dejour (type A, B, C, and D), and Lippacher classification (low and high grade). TT-TG distance was also measured (15 mm considered as normal). Then ACL was assessed on MRI sequences for MD. Criteria for ACL-MD were thickened ACL with increased signal intensity on all MR sequences. Results Among 105 patients with TD, 35 patients (33,3%) had ACL-MD. One-half of the ACL-MD was noted in knees with type A TD (50,0%). According to Lippacher classification, one half of the patients with low-grade dyspslasia had ACL-MD (50,0%). There was also a positive correlation between ACL-MD and TT-TG distance. Conclusion TD and patellar instability are significant risk factors for ACL-MD. Due to the high prevelance of ACL-MD with TD we advised the preoperative evaluation of ACL with knee MRI.

Early investigations into the magnetic resonance imaging (MRI) appearance of articular cartilage imaging relied on assessment of the morphology, with subsequent investigators reporting identifying increased T2 signal intensity, bright signal, in degenerated cartilage. The cartilage “black line sign” is a finding that has recently been described in the radiology literature to characterize cartilage pathology. This sign refers to a focal linear hypointense signal within articular cartilage that is oriented perpendicular to the subchondral bone on T2-weighted MRI. The diagnostic significance and clinical relevance of this sign is debated. Since its first description, several papers have further delineated the etiology, prevalence, and clinical relevance of these and other dark cartilage abnormalities. The intent of this article is to summarize these findings, with hopes of bringing to light the importance of dark cartilage lesions and their clinical implication in the world of knee surgery. We will briefly discuss the most probable etiologies of dark cartilage abnormalities and the major factors determining the unique signal intensity. The described anatomical patterns of this finding, the clinical importance, potential mimics, and current treatment recommendations will be reviewed.

The knee is the most commonly examined joint with magnetic resonance imaging (MRI) and, as such, it is the joint that most trainee radiologists start reporting. This article addresses the main pathologies encountered on MRI examination of the knee, outlining the key features to note and report, as well as providing examples of terminology used to describe these findings.

Introduction: The integrity of articular cartilage determines the functional state of the joint. In recent years, the development of MRI sequences of various articular cartilage has become the focus of many research topics. Objective: The accuracy of diagnosis of knee cartilage injury caused by motion injury was studied retrospectively by meta-three-dimensional software. Methods: Forty-six knee joints of 45 patients with sports injuries, multi-sequence MRI was performed before surgery, including conventional knee MRI (SET1WI, FSEPD/T2WI), 3D SPGR, and 3D FIESTA sequences. Results: According to the operation results, the sensitivity, specificity, positive predictive value, and negative predictive value of 3D SPGR combined with conventional MRI sequence evaluation of cartilage damage are the highest, 73%, 98%, 95%, and 90%. Conclusions: 3D SPGR combined with conventional MRI sequences can improve accurate evaluation and diagnosis of cartilage disease over a reasonable scan time. Level of evidence II; Therapeutic studies - investigation of treatment results. RESUMO Introdução: A integridade da cartilagem articular determina o estado funcional da articulação. Nos últimos anos, o desenvolvimento de sequências de ressonância magnética de várias cartilagens articulares se tornou o foco de muitos tópicos de pesquisa. Objetivo: A precisão do diagnóstico de lesão da cartilagem do joelho causada por lesão de movimento foi estudada retrospectivamente por software meta-tridimensional. Métodos: Quarenta e seis articulações de joelho de 45 pacientes com lesões esportivas, várias sequências de ressonância magnética foram realizadas antes da cirurgia, incluindo ressonância magnética de joelho convencional (SET1WI, FSEPD / T2WI), 3D SPGR e sequências 3D FIESTA. Resultados: De acordo com os resultados da operação, a sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo de 3D SPGR combinado com avaliação de sequência de ressonância magnética convencional de danos na cartilagem são os mais altos, 73%, 98%, 95% e 90%. Conclusões: 3D SPGR combinado com sequências convencionais de ressonância magnética pode melhorar a avaliação precisa e diagnóstico de doença da cartilagem em um tempo de varredura razoável. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento. RESUMEN Introducción: La integridad del cartílago articular determina el estado funcional de la articulación. En los últimos años, el desarrollo de secuencias de resonancia magnética de varios cartílagos articulares se ha convertido en el foco de muchos temas de investigación. Objetivo: La precisión del diagnóstico de la lesión del cartílago de la rodilla causada por una lesión por movimiento se estudió retrospectivamente mediante un software meta-tridimensional. Métodos: Cuarenta y seis articulaciones de rodilla de 45 pacientes con lesiones deportivas, se realizó una resonancia magnética de secuencia múltiple antes de la cirugía, incluida la resonancia magnética de rodilla convencional (SET1WI, FSEPD/T2WI), secuencias 3D SPGR y 3D FIESTA. Resultados: De acuerdo con los resultados de la operación, la sensibilidad, la especificidad, el valor predictivo positivo y el valor predictivo negativo de 3D SPGR combinados con la evaluación de la secuencia de resonancia magnética convencional del daño del cartílago son los más altos, 73%, 98%, 95% y 90%. Conclusiones: 3D SPGR combinado con secuencias de resonancia magnética convencionales puede mejorar la evaluación y el diagnóstico precisos de la enfermedad del cartílago en un tiempo de exploración razonable. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.

PURPOSE: To determine the relationship between femoral–tibial morphometries and anterior cruciate ligament (ACL) pathologies using magnetic resonance imaging (MRI). METHODS: We retrospectively evaluated 455 patients (211 females and 244 males) who underwent knee MRI with suspected ACL pathology. Imaging findings were classified as normal ACL (n = 119), degeneration of the ACL (n = 116), partial ACL tear (n = 103), and complete ACL tear (n = 117). In all groups, the femoral intercondylar notch width (INW), intercondylar distance (CD), notch width index (NWI), and intercondylar notch angle (INA), the angles between the tibial plateau and tibial spines (MPA and LPA), intercondylar eminence peak angle (IEA), and tibial slope angles (MSA and LSA) were measured. RESULTS: Femoral INW and NWI were significantly lower in patients with ACL pathology (p

Objective: While articular cartilage defects are common incidental findings among adult athletes, the effect of running on the cartilage of adolescent athletes have rarely been assessed. This study aims to assess the variations in the articular cartilage of the knees in healthy adolescent basketball players using quantitative T2 MRI (magnetic resonance imaging). Design: Fifteen adolescent basketball players were recruited (13.8 ± 0.5 years old). Girls were excluded to avoid potential gender-related confounding effects. Players underwent a pre-run MRI scan of both knees. All participants performed a 30-minute run on a treadmill. Within 15 minutes after completion of their run, players underwent a second, post-run MRI scan. Quantitative T2 maps were generated using the echo modulation curve (EMC) algorithm. Pre-run scans and post-run scans were compared using paired t test. Results: Participants finished their 30-minute run with a mean running distance of 5.77 ± 0.42 km. Pre-run scans analysis found statistically significant ( P < 0.05) changes in 3 regions of the knee lateral compartment representing the cartilaginous tissue. No differences were found in the knee medial compartment. Post-run analysis showed lower T2 values in the medial compartment compared to the pre-run scans in several weight-bearing regions: femoral condyle central (pre/post mean values of 33.9/32.2 ms, P = 0.020); femoral condyle posterior (38.1/36.8 ms, P = 0.038); and tibial plateau posterior (34.1/31.0 ms, P < 0.001). The lateral regions did not show any significant changes. Conclusions: Running leads to microstructural changes in the articular cartilage in several weight-bearing areas of the medial compartment, both in the femoral and the tibial cartilage.

Comparisons of 5-minute five-sequence knee MRI using simultaneous multislice and parallel imaging acceleration and 10-minute five-sequence knee MRI using parallel imaging acceleration only suggest ...

This study aimed to investigate the morphological variations in the cross-sectional anatomy of the meniscus between similar-sized matched menisci. Knee MRI of 329 patients with intact menisci were retrospectively reviewed, and the meniscal length (ML), meniscal width (MW), and cross-sectional dimensions (meniscal height and width) of the anterior, posterior horns, and the corpus were measured. Patients with similar-sized menisci who had less than 1 mm difference in ML and MW were matched. 330 male-to-male medial menisci (MM), 623 male-to-male lateral menisci (LM), 82 female-to-female MM, 233 female-to-female LM, 176 cross-gender MM, and 265 cross-gender LM unique combination of ideally matched pairs (total: 1709) were generated. The disparity in the cross-sectional dimensions, absolute difference, and the paired percent differences was statistically analyzed. The ML and MW in all groups were statistically similar, with a predefined absolute difference of 1 mm both for ML and MW (paired percent difference

Place: France; International audience; PURPOSE: The purpose of this study was to assess and compare the prevalence of meniscal, ligament and cartilage lesions on knee MRI in a series of age- and sex-matched patients with and without medial meniscal ossicle.MATERIALS AND METHODS: Forty-two knee MRI examinations obtained in 42 patients (36 men, 6 women; mean age, 42.5±22.2 [SD] years; range: 19-65years) on which a medial meniscal ossicle was present were compared to 42 knee MRI examinations obtained in 42 age- and sex-matched patients (36 men, 6 women; mean age, 41.8±20.6 [SD] years; range: 19-65years) on which no medial meniscal ossicles were present. Two radiologists (R1, R2) blinded to the presence of meniscal ossicle by reading only the fat-saturated intermediate-weighted MR images separately assessed the presence of meniscal, ligament and cartilage lesions on these 84 knee MRI examinations. Prevalence of meniscal and ligament lesions and degree of cartilage degradation at MRI were compared between knees with and those without medial meniscal ossicle.RESULTS: In knees with medial meniscal ossicle, R1 and R2 detected 33 (79%) and 38 (90%) medial meniscal lesions, respectively that involved the posterior root (n=25/32 for R1/R2), the posterior horn (n=19/14 for R1/R2) or the body (n=8/10 for R1/R2). The prevalence of posterior root tear (60% [25/42]/76% [32/42] for R1/R2) and that of anterior cruciate ligament (ACL) lesions (48% [20/42]/57% [24/42] for R1/R2) as well as the medial cartilage degradation score (3.35±0.87 [SD] for R1 and 3.92±0.78 [SD] for R2) were significantly greater in knees with than in knees without medial meniscal ossicle (root lesions: P\textless0.01 for both readers; ACL lesions and medial cartilage score: P\textless0.01 for both readers).CONCLUSION: On MRI examination, knees with a medial meniscal ossicle demonstrate a greater frequency of medial posterior root tear and of ACL lesions and a greater degree of medial femoro-tibial cartilage degradation by comparison with knees without medial ossicle.

Background Bone-cartilage mismatch is a variation in which the surface curvature of the articular cartilage is incongruent with the curvature of the underlying subchondral bone. The purpose of this study is to investigate the prevalence of this variant in the medial tibial plateau (MTP) and examine potential association with clinical findings and intra-articular derangements using MRI. Methods A quantitative and qualitative retrospective analysis of 98 knee MRI studies was performed. Bone and cartilage depths of the MTP were measured to assess bone-cartilage morphology and classified into congruent (concave bone-concave cartilage) and incongruent (concave bone-convex cartilage) patterns. Associations between bone-cartilage mismatch and clinical findings and other MRI changes were assessed using Fisher’s exact test. Results By quantitative assessment, four individuals (4%) had MTP incongruent morphology (bone-cartilage mismatch). The mean bone depth ± standard deviation (SD) was 2.3 ± 0.6 mm concave in the congruent group, and 1.4 ± 0.6 mm concave in the incongruent group. The mean cartilage depth ± SD was 0.7 ± 0.7 mm concave in the congruent group, and 0.9 ± 0.5 mm convex in the incongruent group. By qualitative assessment, three individuals (3%) had incongruent morphology. Although not statistically significant, a higher proportion of individuals (3 of 4; 75%) with incongruent cartilage demonstrated chondromalacia patellae compared to those with congruent cartilage (38 of 94; 40%). Conclusion Bone-cartilage mismatch was present in 3–4% of the knees. Individuals with incongruent cartilage demonstrated a trend of a higher proportion of chondromalacia patellae. Larger studies are needed to evaluate this further.

Age estimation is a crucial element of forensic medicine to assess the chronological age of living individuals without or lacking valid legal documentation. Methods used in practice are labor-intensive, subjective, and frequently comprise radiation exposure. Recently, also non-invasive methods using magnetic resonance imaging (MRI) have evaluated and confirmed a correlation between growth plate ossification in long bones and the chronological age of young subjects. However, automated and user-independent approaches are required to perform reliable assessments on large datasets. The aim of this study was to develop a fully automated and computer-based method for age estimation based on 3D knee MRIs using machine learning. The proposed solution is based on three parts: image-preprocessing, bone segmentation, and age estimation. A total of 185 coronal and 404 sagittal MR volumes from Caucasian male subjects in the age range of 13 and 21 years were available. The best result of the fivefold cross-validation was a mean absolute error of 0.67 ± 0.49 years in age regression and an accuracy of 90.9%, a sensitivity of 88.6%, and a specificity of 94.2% in classification (18-year age limit) using a combination of convolutional neural networks and tree-based machine learning algorithms. The potential of deep learning for age estimation is reflected in the results and can be further improved if it is trained on even larger and more diverse datasets.

OBJECTIVE: Deep learning (DL) image reconstruction has the potential to disrupt the current state of MRI by significantly decreasing the time required for MRI examinations. Our goal was to use DL to accelerate MRI to allow a 5-minute comprehensive examination of the knee without compromising image quality or diagnostic accuracy. MATERIALS AND METHODS. A DL model for image reconstruction using a variational network was optimized. The model was trained using dedicated multisequence training, in which a single reconstruction model was trained with data from multiple sequences with different contrast and orientations. After training, data from 108 patients were retrospectively undersampled in a manner that would correspond with a net 3.49-fold acceleration of fully sampled data acquisition and a 1.88-fold acceleration compared with our standard twofold accelerated parallel acquisition. An interchangeability study was performed, in which the ability of six readers to detect internal derangement of the knee was compared for clinical and DL-accelerated images. RESULTS. We found a high degree of interchangeability between standard and DL-accelerated images. In particular, results showed that interchanging the sequences would produce discordant clinical opinions no more than 4% of the time for any feature evaluated. Moreover, the accelerated sequence was judged by all six readers to have better quality than the clinical sequence. CONCLUSION. An optimized DL model allowed acceleration of knee images that performed interchangeably with standard images for detection of internal derangement of the knee. Importantly, readers preferred the quality of accelerated images to that of standard clinical images.

Clinically measured Quadriceps angle (Q-angle) has low reliability. Measurement of angle between femoral shaft and patellar tendon (FSPT angle) on routine knee MRI was described in this study to represent the lateral vector forces of quadriceps mechanism. The cross-sectional study was designed to compare this angle between subjects with objective patellofemoral instability (PFI) versus those without PFI, to assess its reliability, and to assess its validity in terms of its ability to differentiate between PFI and non-PFI subjects using the “Receiver Operating Characteristic” (ROC) curve. MRI scans of 20 subjects with PFI and 20 without PFI were obtained. FSPT angle was measured in each MRI by three different raters. In addition, the clinical Q-angle was also measured in the control group. The FSPT angle was significantly higher in PFI group as compared with the non-PFI group (p

OBJECTIVE. Cartilage loss on preoperative knee MRI is a predictor of poor outcomes after arthroscopic partial meniscectomy. The purpose of this study was to compare the ability to predict outcomes after arthroscopic partial meniscectomy with a clinically used modified Outerbridge system versus a semiquantitative MRI Osteoarthritis Knee Score system for grading cartilage loss. MATERIALS AND METHODS. Patients who underwent preoperative knee MRI within 6 months of arthroscopic partial meniscectomy and who had outcomes available from the time of surgery and 1 year later were eligible for inclusion. Cases were evaluated by two radiologists and one radiology fellow with the use of both grading systems. The accuracy of each system in discriminating between surgical success and failure was estimated using the ROC curve (AUC) with 95% CIs. A Wald test was used to assess noninferiority of the clinical grading system. Interreader agreement regarding the accuracy of the grading systems in predicting outcomes was also compared. RESULTS. A total of 78 patients (38 women and 40 men; mean age, 56.6 years) were included in the study. A prediction model using clinical grading (AUC = 0.695; 95% CI, 0.566-0.824) was noninferior (p = 0.047) to a model using MRI Osteoarthritis Knee Score grading (AUC = 0.683; 95% CI, 0.539-0.827). Both MRI prediction models performed better than a model using demographic characteristics only (AUC = 0.667; 95% CI, 0.522-0.812). Inter-reader agreement with clinical grading (80.8%) was higher than that with MRI Osteoarthritis Knee Score grading (65.0%; p = 0.012). CONCLUSION. A clinically used system to grade cartilage loss on MRI is as effective as a semiquantitative system for predicting outcomes after arthroscopic partial meniscectomy, while also offering improved interreader agreement.

The aim of this study was to propose and validate a new six-item topographical classification of knee bone marrow lesions in coronal MRI images, to provide an easy-to-use aid to describe their location in a more reproducible and accurate way. This study was conducted in four phases. The first was to do a literature search for methods of describing bone marrow lesions in MRI of the knee. The second was creation of a six-area topographic classification of bone marrow lesions in coronal MRI of the knee. The third phase was selection of cases with bone marrow lesions on knee MRI performed in a single hospital between January of 2017 and December of 2018. The fourth phase was categorization of the bone marrow lesions’ location according to the new proposed classification by three independent examiners, two orthopedic surgeons and one radiologist. Patient’s demographic data and associated lesions were collected. The inter-observer and intra-observer reliability of the proposed classification was then calculated. MRI examination of 4000 patients were studied and in 520 patients a total of 666 bone marrow lesions were identified and their location classified using the new system. The inter-observer and intra-observer reliability analysis found a Fleiss’ Kappa value of 0.96 (0.95–0.97) and 0.97 (0.96–0.97), respectively, confirming the high reproducibility of the proposed classification. The proposed six-location classification of bone marrow lesions is highly reproducible and can help researchers develop studies and share information in a more accurate and reliable way. The correct classification of bone marrow lesions can lead to a more accurate description of this pathology and help clinicians to propose appropriate therapies for this group of patients. V.

Amaç: Patella tiplerindeki farklılıkların, menisküs üzerindeki yükü değiştirerek ve yürüme mekaniğinde değişikliğe neden olarak menisküs rüptürünün etiyolojisinde rol oynayabileceğini düşünüyoruz. Bu çalışmada patella tiplerinin dağılımı ve menisküs rüptürü ile ilişkisi araştırıldı.Materyal ve Metod: Bu çalışmada, Ocak 2017- Temmuz 2018 tarihleri arasında Fizik Tedavi ve Rehabilitasyon polikliniğine başvuran 510 hastanın diz manyetik rezonans (MR) incelemeleri patella tiplerinin ayırımı ve menisküs rüptürünün dağılımı açısından PACS sisteminde retrospektif olarak tekrar değerlendirildi. Hastaların klinik öyküleri, muayene bulguları, yaşları ve cinsiyetleri hastanenin kayıt sisteminden alındı. On sekiz yaş altındaki hastalar, majör travma öyküsü olan ve ameliyat edilen hastalar çalışma dışı bırakıldı. Diz MR incelemesi 3-Tesla magnet gücüne sahip MR cihazı (MagnetomSkyra, Siemens Healthcare, Erlangen, Almanya) ile standart diz koili kullanılarak gerçekleştirildi. Patella tipi sınıflamasında aksiyel PD görüntüleri kullanılarak, Baumgartl ve arkadaşlarının yaptıkları sınıflama esas alındı. Buna göre; Tip I: İçbükey ve eşit uzunluktaki medial ve lateral fasetler. Tip II: Medial faset düz veya içbükeydir, lateral faset medial fasetten daha belirgindir. Tip III: Daha küçük medial faset mevcut ve dışbükeydir. Tip IV: Medial faset veya merkez kenarı yoktur, jokey şapkası olarak adlandırılır. Elde edilen sayısal veriler, yaş, cinsiyet patella tipi ve menisküs yırtılması açısından SPSS 20.0 (SPSSInc., Chicago IL, USA) versiyonu istatistik paket programı kullanılarak işlendi. Bulgular: Çalışmaya alınan 238 (%46,7) kadın, 272 (%53,3) erkek toplam 510 hasta, patella tipi ve menisküs rüptürü açısından değerlendirildi. Hastaların ortalama yaşları 38.83 ± 0.5 idi (en az 18, en çok 76). Tüm hastalarda Tip I patella 132 (%25,9) Tip II 354 (%69,4) Tip III 24 (%4,7) olarak bulundu. 376 hastada, %73,7 oranında menisküs yırtılması tespit edilmedi ve 134 (%26,3) hastada menisküs yırtılması vardı. Menisküs yırtığı olan hastaların 68'i (%50,7) kadın, 66'sı (%49,3) erkekti. Sonuç: Farklı patella tiplerinde simetrik ve simetrik olmayan yükleme sonucu menisküs üzerindeki orantısız veya simetrik olmayan basınç sonucu menisküs rüptürü eğiliminin artacağını düşündük. Ancak çalışmamızda meniskal rüptür ile patella tipleri arasında istatistiksel olarak anlamlı bir ilişki bulamadık.

To quantify the prevalence of complete tibial insertion of the biceps femoris tendon in patients presenting for knee MRI scans. Knee MRI scans over a 4-year period (2014–2018) were accessed at a tertiary referral centre and community-based private practice. A total of 433 scans were reviewed. 30 scans were excluded from the study due to repeat imaging or incomplete coverage of the biceps femoris tendon insertion. Appearances of the distal biceps tendon bony insertion were scrutinized on the remaining 403 scans. Each biceps femoris tendon insertion was classified into one of the four categories—complete fibular insertion, predominant fibular insertion, predominant tibial insertion and complete tibial insertion. Out of the final 403 scans included in the study, five cases of complete tibial insertion of the biceps femoris tendon were identified (just over 1% of the total population). 42 cases were identified as having predominant tibial insertion (10% of the total population). 113 cases had predominantly fibular insertion and 243 cases had complete fibular insertion. Complete anomalous insertion of the biceps femoris tendon on the anterolateral tibia is an uncommon entity. Such an attachment is found in approximately 1% of patients presenting for MRI evaluation of the knee.

Purpose Knee tibiofemoral osteoarthritis (KOA) is a major health problem, affecting approximately 30% of elderly. Several studies have reported that the loss of patellar cartilage is associated with an increased risk of KOA. However, no study has reported the optimal cut off value of patellar cartilage cross-sectional area (PCA) in KOA. We hypothesize that PCA is a new sensitive morphologic parameter in the diagnosis of KOA. The purpose of this study was to determine whether PCA could be used as an important adjuvant morphological parameter in the diagnosis of KOA. Patients and methods Data regarding PCA were collected from 88 subjects with KOA. A total of 77 subjects in the control group underwent knee MRI as part of nonsymptomatic medical examination. T2-weighted axial images were acquired from both groups. Using a picture archiving communications system, we analyzed the cross-sectional area of the patellar cartilage on MRI. Results The average PCA was 98.66±22.18 mm2 in the control group, which was significantly (p

Purpose We compared two imaging techniques to assess whether 3D VISTA imaging could replace 2D FSE in diagnosing PCL reconstruction complications. Materials and methods This retrospective study included 40 patients who underwent surgery of PCL reconstruction and follow-up knee MRI (3D VISTA and 2D FSE) for evaluation of PCL graft integrity. Each image was interpreted independently by two radiologists without knowledge of radiologic reports or clinical history. The diagnostic performance of the 2D FSE PCL view, 3D VISTA PCL view, orthogonal 2D FSE image, and combined sequences were evaluated in terms of sensitivity, specificity, and accuracy for diagnosing complications of PCL graft. The reference diagnoses were made arthroscopically or clinically. Results The sensitivities of the 3D VISTA PCL view were similar to those of the 2D PCL view. The sensitivities of the combination of the orthogonal view and the 3D VISTA PCL view were also similar to those of the combination of the orthogonal view and the 2D PCL view. The specificities and accuracies of each image exhibited similar results. There was no statistically significant difference in diagnostic performance between the 3D VISTA PCL view and the 2D PCL view (solitary or combined with the orthogonal view). Conclusions The diagnostic performance of the PCL views on 3D VISTA images is comparable to that of 2D FSE images in the diagnosis of PCL graft complications.

To evaluate the appropriateness of MRI ordering practices and their effect on clinical management for nontraumatic knee pain at the primary care clinics of a large public urban hospital.In all, 196 consecutive MRIs for nontraumatic knee pain ordered from primary care clinics in a large public urban hospital over an 18-month period were studied. ACR Appropriateness Criteria (AC) scores for nontraumatic knee pain were retrospectively calculated from medical record reviews. The record was also reviewed to assess whether knee MRI changed clinical management. Knee osteoarthritis grading was performed. Tests were performed for differences in age, body mass index (BMI), gender, and ethnicity among appropriate and inappropriate MRIs.Of the MRIs, 57% (108 knees) had "usually appropriate" (ie, 7-9) and 43% (8 knees) had "usually not appropriate" (ie, 1-3) AC scores (P.1). Clinical management was changed in 26% of knees with "usually appropriate" and 20% of knees with "usually inappropriate" scores (P.05), and 70% of the knees with "usually appropriate" and 61% of the knee with "usually not appropriate" scores had moderate to severe osteoarthritis. Age, BMI, gender, and ethnicity had no significant effect on AC scores.In patients referred from primary care for MRI for nontraumatic knee pain, adherence to AC was low. Additional focus on reducing "appropriate" studies that do not impact clinical management (eg, cases with radiographically evident moderate to severe osteoarthritis) is also warranted.

This article highlights five knee injuries that, in the author's experience, are commonly overlooked by readers inexperienced in knee MRI: ramp lesions, meniscocapsular tears, meniscal root ligament tears, posterior capsular ligament tears, and partial anterior cruciate ligament tears. Although these injuries are readily apparent when the images are assessed for the given abnormality, the author believes they may be overlooked because either the injury is not considered or the affected area is not closely inspected. These injuries may not alter immediate clinical management or require surgical intervention; nevertheless, they may result in patient symptoms and may potentially increase the risk of further knee injury. Moreover, these injuries are difficult to recognize clinically and arthroscopically. This review presents these five injuries, emphasizing relevant anatomy, normal MRI appearances, common injury patterns, and tips to avoid overlooking them. Routine review of these areas when interpreting knee MRI, with additional imaging as necessary, will allow these injuries to be recognized more regularly.

In this paper we evaluate two unsupervised approaches to denoise Magnetic Resonance Images (MRI) in the complex image space using the raw information that k-space holds. The first method is based on Stein’s Unbiased Risk Estimator, while the second approach is based on a blindspot network, which limits the network’s receptive field. Both methods are tested on two different datasets, one containing real knee MRI and the other consists of synthetic brain MRI. These datasets contain information about the complex image space which will be used for denoising purposes. Both networks are compared against a state-of-the-art algorithm, Non-Local Means (NLM) using quantitative and qualitative measures. For most given metrics and qualitative measures, both networks outperformed NLM, and they prove to be reliable denoising methods.

Background and aim: Recently, there has been a growing interest in the use of Dixon sequence for knee MRI in order to save time spent on the scanner, and improving diagnostic utility. Our purpose was to compare the diagnostic performance of Dixon sequence on low-field MRI with the proton-density sequence on high-field MRI. Methods: This prospective study included 40 patients who underwent 0.25T knee MRI, using the routine protocol with the addition of a sagittal 4-point Dixon sequence (SPED), and an additional sequence on 1.5T scanner, consisting in a fat-suppressed proton-density fast-spin-echo (FS PD-FSE). Two radiologists independently examined the images, evaluating the anatomic identification score and diagnostic performances of the two sequences. Interreader agreement was evaluated using an intraclass correlation coefficient (ICC). Results: Final population counted 34 patients (36 knee MR images) with a mean age of 52.9 years (range, 18–75 years). Interreader agreement was very high except for cartilage injuries at medial femoral condyle and medial tibial plateau (ICC SPED: 0.757, ICC FS PD-FSE: 0.746), even if not statistically significant. There were no significant differences in mean signal-to-noise ratio (SNR), artifacts presence and diagnostic confidence between SPED and PD-FS sequence. Conclusions: Dixon sequences on low-field scanner have a comparable diagnostic accuracy to PD-FS sequence obtained on a high field scanner for knee MR imaging. (www.actabiomedica.it)

This paper focuses on different types of backbone networks for machine learning architectures which perform classification of knee Magnetic Resonance Imaging (MRI) images. This paper aims to compare different types of feature extraction networks for the same classification task, in terms of accuracy and performance. Multiple variations of machine learning models were trained based on the MRNet architecture, choosing AlexNet, ResNet, VGG-11, VGG-16, and Efficientnet as the backbone. The models were evaluated on the MRNet validation dataset, computing Area Under the Receiver Operating Characteristics Curve (ROC-AUC), accuracy, f1 score, and Cohen’s Kappa as evaluation metrics. The MRNet-VGG16 model variant shows the best results for Anterior Cruciate Ligament (ACL) tear detection. For general abnormality detection, MRNet-VGG16 is dominated by MRNet-Resnet in confidence between 0.5 and 0.75 and by MRNet-VGG11 for confidence more than 0.8. Due to the non-uniform nature of backbone network performance on different MRI planes, it is advisable to use an LR ensemble of: VGG16 on a coronal plane for all classification tasks; on an axial plane for abnormality and ACL tear detection; Alexnet on a sagittal plane for abnormality detection, and an axial plane for meniscal tear detection; and VGG11 on a sagittal plane for ACL tear detection. The results also indicate that the Cohen’s Kappa metric is valuable in model evaluation for the MRNet dataset, as it provides deeper insights on classification decisions.

Background Osteoarthritis (OA) of the knee joint is a common cause of chronic disability in older adults. During the past 10 years, the infrapatellar fat pad (IPFP) has emerged as a new player in the pathogenesis of knee OA. Its exact role in the pathogenesis of knee OA remains uncertain. While many studies focused on the detrimental effect of the chemical mediators released by IPFP and their role in the accentuation of the development of OA, only few studies elucidated the beneficial effect of IPFP maximal area as a local shock absorber protecting the adjacent articular structures from progressive damage. The aim of this study was to evaluate the relation between the IPFP maximal area and the prevalence of OA manifestations. We also studied the relation between the subcutaneous (SC) fat thicknesses on the medial aspect of the knee as a surrogate marker of body obesity and the IPFP area. Results A total of 216 knee scans for 188 adult patients (64 males and 124 females) who met the inclusion criteria were examined. They were between 45 and 66 years (mean 52.5 years). The mean IPFP area for all patients was 6.9 cm2 (± 1.6 SD) (ranged from 4.5 to 11 cm2). After adjustment for potential confounders, there was a significant negative association between IPFP area and radiographic manifestations of OA (osteophites, joint space narrowing, and grade of OA) (P value P value Conclusion In our study, we found supportive evidence that IPFP maximal area is associated with fewer osteoarthritic knee changes and less cartilage damage, suggesting that it plays a protective role against the development and progression of OA. Further large-scale clinical studies are awaited to confirm the obtained results. Based on our findings, it would be recommended to avoid IPFP resection during surgery in order to maintain its protective effect.

View planning is the process of prescribing slices for diagnostic imaging. It is an important part of the magnetic resonance imaging (MRI) investigation workflow affecting both speed and quality of diagnoses made by physicians. In this chapter, we present a framework for automatic view planning (AVP) consisting of a universal, deep multi-layer discriminative architecture for landmark detection and several pre-processing and post-processing algorithms designed for different kinds of MRI data. The framework is applicable to a wide variety of MRI procedures such as brain, cardiac, knee and spine MRI. The AVP framework and performance of underlying algorithms were calculated on real clinical MRI data and implemented as a product-ready solution. Evaluation results show superior quality and speed over competitors.

Radiologists tend to possess human error during pathologies scans for any abnormalities; thus, the introduction of automation shall has a great impact on accurately detecting injuries and more musculoskeletal examinations. Magnetic Resonance Imaging (MRI) scans are an effective method to detect injured sections but the process tends to be time-consuming and prone to human error. Therefore, our paper highlights the automation impact on knee MRI for abnormal, anterior cruciate ligament (ACL), meniscal damages using deep learning. Deep learning model such as Convolutional Neural Network (CNN) can infer the representation of images due to its properties: local connection and shared weights. We have explored two deep CNN models (VGG16 and VGG19) with transfer learning approach to predict knee injury on MRNet dataset collected by Stanford University. The classification accuracy obtained for abnormal, ACL tear, and meniscal tear are 83.19%, 84.96%, and 70.80%, respectively, using VGG16, whereas 84.07%, 84.96%, and 74.34%, respectively, using VGG19 model.

Background This work was conducted to assess the diagnostic efficiency of isotropic three-dimensional VISTA-fast spin echo versus standard two-dimensional fast spin echo at 1.5 T MRI, in the assessment of internal knee derangement in symptomatic patients, aiming to obtain similar diagnostic accuracy in a shorter time span, with reduction of partial volume artifacts by thin continuous sections. Results This was a non-randomized control study including 39 patients (32 male and 7 females, mean age 37 years old). A correlative study was done utilizing MRI standard 2D FSE (protocol A) versus 3D-VISTA-FSE (protocol B) for medial meniscus (MM) and lateral meniscus (LM), as well as anterior cruciate ligament ACL lesions, comparing the MRI results with the findings of arthroscopy as the gold standard. Both protocols depicted medial meniscus lesions with accuracy, specificity, and sensitivity (97.44%, 96.30%, and 100% respectively), lateral meniscus lesions with accuracy, specificity, and sensitivity (97.44%, 100%, and 50% respectively), and ACL lesions with accuracy, specificity, and sensitivity (100%, 100%, and 100% respectively), while there were no PCL lesions depicted through the study population. Comparing the time factor between both protocols revealed protocol A to consume 13.7 min, while protocol B consumed 6.6 min. Conclusion Three-dimensional isotropic VISTA-FSE sequence, although having similar accuracy in diagnosing cruciate and meniscal lesions as the standard sequences, facilitates thin-section data acquisition and multi-planar image reformation in standard and non-standard planes, without intersection gaps that are crucial for the detection and dissection of compound structures; also, it allows a shorter time span, which is more advantageous for patients, particularly the traumatized and emergency patients.

Osteoarthritis (OA) of the knee is a major source of disability that has no known treatment or cure. Morphological and compositional MRI is commonly used for assessing the bone and soft tissues in the knee to enhance the understanding of OA pathophysiology. However, it is challenging to extend these imaging methods and their subsequent analysis techniques to study large population cohorts due to slow and inefficient imaging acquisition and postprocessing tools. This can create a bottleneck in assessing early OA changes and evaluating the responses of novel therapeutics. The purpose of this review article is to highlight recent developments in tools for enhancing the efficiency of knee MRI methods useful to study OA. Advances in efficient MRI data acquisition and reconstruction tools for morphological and compositional imaging, efficient automated image analysis tools, and hardware improvements to further drive efficient imaging are discussed in this review. For each topic, we discuss the current challenges as well as potential future opportunities to alleviate these challenges. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Approximately two-thirds of the routine knee magnetic resonance imaging (MRI) demonstrates an articular cartilage damage [1]. Chondral injuries can occur de novo or in association with degenerative or traumatic etiologies. Therefore, a careful evaluation of the articular cartilage is an integral part of the knee MRI examination. With an increase in the availability of the treatment options for the articular cartilage lesions, MRI has taken a front seat in the identification and determination of the extent and severity of the chondral lesions. MRI is the investigation of choice and the best non-invasive modality for the evaluation of chondral lesions with an arthroscopy being accepted as the gold standard. The purpose of this chapter is to differentiate between chondral, osteochondral, subchondral, and osteoarthritis lesions on MRI and to discuss the various radiological terminologies pertaining to these lesions. The chapter also utilizes the commonly recommended grading systems for the chondral and the osteochondral lesions.

Please see the Editorial Comment by Derik L. Davis discussing this article. BACKGROUND. Potential approaches for abbreviated knee MRI, including prospective acceleration with deep learning, have ac...

To evaluate potential clinical acceleration factors of Compressed SENSE (CS)Twenty healthy volunteers were scanned with a 3 T scanner, all receiving a standard, fs 2D PD, three CS (CS 2, CS 3, CS 5) as well as time-equivalent SENSE accelerations (S 2, S 3, S 5). The fs 3D PD sequence was acquired with four CS (CS 6, CS 8, CS 10, CS 15) and equivalent SENSE (S 5.72, S 7.69, S 9.57, S 14) factors. Three independent readers rated the images. Signal-to-noise, contrast-to-noise, root-mean-square error and structural similarity index were analyzed for objective evaluation.Scan time decreased with increasing CS factor (2D CS 2: 145 s, 2D CS 3: 95 s, 2D CS 5: 57 s, 3D CS 6: 293 s, 3D CS 8: 220 s, 3D CS 10: 176 s, 3D CS 15: 119 s). The 2D standard sequence was rated best for diagnostic certainty and overall image impression with an average of 4.97 ± 0.10 and 4.80 ± 0.24 (all p 0.05), except for 2D CS 2 and 2D S 2. For the 3D sequences, the standard sequence performed better for both parameters for CS 15, S 9.57 and S 4, as well as S 7.69 for overall image impression while CS 8 was non-inferior for all tested criteria and CS 10 only inferior for delineation of the anterior cruciate ligament, both outperforming the time-equivalent SENSE accelerations.Compressed SENSE can significantly decrease (34.39 % for 2D CS 2 and 54.17 % for 3D CS 10) scan time in knee imaging with unchanged diagnostic certainty and overall image impression compared to the clinical reference.

Purpose To investigate the diagnostic performance of three-dimensional (3D) MRI for depicting meniscal injuries of the knee by using surgery as the standard of reference. Materials and Methods A literature search was performed to identify original studies published between 1985 and 2017. Summary receiver operating characteristic curve and sensitivity analyses were performed to compare the diagnostic performance of 3D versus two-dimensional (2D) MRI for the assessment of knee meniscal injuries and to evaluate the impact of relevant covariates on the diagnostic performance for assessment of knee meniscal injuries. Results Of identified records, 31 studies (1743 3D knee MRI examinations) were included (23 studies also reported the results of 2D MRI). All studies before 2008 used gradient-echo (GRE) sequences, whereas all studies after 2011 used fast spin-echo (FSE) sequences. By comparing FSE and GRE sequences with 2D MRI, pooled estimate of sensitivity (90.0%; P = .2 and 90.1%; P = .2 vs 88.5%) and pooled estimate of specificity (91%; P = .3 and 89.8% vs 90.1%; P = .7) were comparable. The 3D FSE sequences demonstrated similar diagnostic performance as 3D GRE sequences, except for slightly improved sensitivity for depicting lateral meniscal injuries (FSE, 84.6%; GRE, 75%; P = .01). The specificity of 3D sequences improved when multiplanar reformatting was performed (P = .02). Conclusion Both three-dimensional (3D) fast spin-echo (FSE) and 3D gradient-echo (GRE) sequences had similar diagnostic performance as two-dimensional sequences, with slight superior sensitivity of 3D FSE sequences compared with 3D GRE sequences for depicting lateral meniscal injuries of the knee. © RSNA, 2018 Online supplemental material is available for this article.

Pigmented villonodular synovitis (PVNS) is caused by a proliferation of the synovial membrane and can be a rare cause of pain and locking of the knee. In its localized form, it can be removed arthroscopically. We describe in detail a step-by-step arthroscopic technique applied to treat a 27-year-old patient who had been suffering from pain and episodes of locking for a year and whose left knee MRI revealed an intra-articular mass. The formation was completely enucleated arthroscopically and histological analyses confirmed the diagnosis of localized PVNS. There were no complications, and the patient was symptom-free at the six-month follow-up with no clinical or radiological evidence of recurrence.

BACKGROUND: Clinical knee MRI protocols require upwards of 15 minutes of scan time. PURPOSE/HYPOTHESIS: To compare the imaging appearance of knee abnormalities depicted with a 5-minute 3D double-echo in steady-state (DESS) sequence with separate echo images, with that of a routine clinical knee MRI protocol. A secondary goal was to compare the imaging appearance of knee abnormalities depicted with 5-minute DESS paired with a 2-minute coronal proton-density fat-saturated (PDFS) sequence. STUDY TYPE: Prospective. SUBJECTS: Thirty-six consecutive patients (19 male) referred for a routine knee MRI. FIELD STRENGTH/SEQUENCES: DESS and PDFS at 3T. ASSESSMENT: Five musculoskeletal radiologists evaluated all images for the presence of internal knee derangement using DESS, DESS+PDFS, and the conventional imaging protocol, and their associated diagnostic confidence of the reading. STATISTICAL TESTS: Differences in positive and negative percent agreement (PPA and NPA, respectively) and 95% confidence intervals (CIs) for DESS and DESS+PDFS compared with the conventional protocol were calculated and tested using exact McNemar tests. The percentage of observations where DESS or DESS+PDFS had equivalent confidence ratings to DESS+Conv were tested with exact symmetry tests. Interreader agreement was calculated using Krippendorff’s alpha. RESULTS: DESS had a PPA of 90% (88–92% CI) and NPA of 99% (99–99% CI). DESS+PDFS had increased PPA of 99% (95–99% CI) and NPA of 100% (99–100% CI) compared with DESS (both P < 0.001). DESS had equivalent diagnostic confidence to DESS+Conv in 94% of findings, whereas DESS+PDFS had equivalent diagnostic confidence in 99% of findings (both P < 0.001). All readers had moderate concordance for all three protocols (Krippendorff’s alpha 47–48%). DATA CONCLUSION: Both 1) 5-minute 3D-DESS with separated echoes and 2) 5-minute 3D-DESS paired with a 2-minute coronal PDFS sequence depicted knee abnormalities similarly to a routine clinical knee MRI protocol, which may be a promising technique for abbreviated knee MRI.

The objective of our study was to evaluate the association between anterior tibial translation and injuries on the posterior horn medial meniscus (PHMM) and the integrity of the brake stop mechanism of the PHMM in the anterior cruciate ligament (ACL)-deficient knee.This retrospective study included 85 consecutive patients with an arthroscopically confirmed complete ACL tear. Anterior tibial translation was quantitatively measured using sagittal MRI at the midpoint of the lateral femoral condyle. The "uncovered medial meniscus" sign was considered positive if a vertical line tangent to the posteriormost margin of the medial tibial plateau intersected the PHMM at the midpoint of the medial femoral condyle on sagittal MRI. Concomitant injuries on the structures of the posteromedial and posterolateral corners of the knee, including PHMM tear and meniscal ramp lesion, were recorded. Stratified subgroup analysis and multivariable regression analysis were performed to identify factors associated with anterior tibial translation.The uncovered medial meniscus sign was positive in 21.2% (18/85) of patients and was significantly associated with anterior tibial translation. In the stratified subgroup analysis and multivariable regression analysis, positive uncovered medial meniscus sign consistently showed a significant association with anterior tibial translation and generated an additional 2.8 mm of anterior tibial translation. Other injuries, including PHMM tear and meniscal ramp lesion, were not associated with anterior tibial translation.The uncovered medial meniscus sign showed a statistically significant correlation with anterior tibial translation and could be a useful marker for the lost brake stop mechanism of PHMM in the ACL-deficient knee.

Introduction The aim of the study was to evaluate the performance of radiographers in image interpretation of magnetic resonance imaging (MRI) brain, spine and knee examinations following a nine-month work based postgraduate MRI module. Methods Twenty-seven participants each submitted 60 image commentaries taken from prospective clinical workloads. The image interpretations (n = 1620) comprised brain, spine, and knee MRI examinations. Prevalence of abnormal examinations approximated 53% (brain), 74% (spine), and 73% (knee), and included acute and chronic pathology, normal variants and incidental findings. Each image interpretation was graded against reference standard consultant radiologist definitive report. Results The radiographer's performance on brain image interpretations demonstrated mean accuracy at 86.7% (95% CI 83.4–89.3) with sensitivity and specificity of 84% (95% CI 80.9–86.4) and 89.7% (95% CI 86.2–92.6) respectively. For spinal interpretations the mean accuracy was 86.4% (95% CI 83.4–89.0), sensitivity was 90.2% (95% CI 88.2–92), mean specificity was 75.3% (95% CI 69.4–80.4). The mean results for knee interpretation accuracy were 80.9% (95% CI 77.3–84.1), sensitivity was 83.3% (95% CI 80.8–85.5), with 74.3% specificity (95% CI 67.4–80.4). Conclusions The radiographer's demonstrated skills in brain, spine and knee MRI examination image interpretation. These skills are not to replace radiologist reporting but to meet regulating body standards of proficiency, and to assist decision making in communicating unexpected serious findings, and/or extend scan range and sequences. Further research is required to investigate the impact of these skills on adjusting scan protocols or flagging urgent findings in clinical practice.

The studies of the relationship between anterior cruciate ligament (ACL) injury and notch size were in 2-D parameters in Han Chinese, the largest nation in the world, while few studies referred to the 3-D notch volume. The purpose of this study was to determine the differences in notch volume between individuals with and without ACL injuries and the optimal criterion value for abnormal notch volume and its sensitivity in predicting the risk of ACL injuries. Two hundred eighty individuals were included in this study, including 140 patients with non-contact sports ACL injuries only and 140 age- and gender-matched individuals without ACL injuries. Both groups underwent pre-operative knee MRI examinations and femoral notches were traced manually on 2-D MRI images, then 3-D notch volume was calculated. The notch volume was extremely smaller in the ACL-injured group than that in the control group (5.94 ± 1.35 versus 6.86 ± 1.61 cm3, P

A fully automated knee MRI segmentation method to study osteoarthritis (OA) was developed using a novel hierarchical set of random forests (RF) classifiers to learn the appearance of cartilage regions and their boundaries. A neighborhood approximation forest is used first to provide contextual feature to the second-level RF classifier that also considers local features and produces location-specific costs for the layered optimal graph image segmentation of multiple objects and surfaces (LOGISMOS) framework. Double echo steady state (DESS) MRIs used in this work originated from the Osteoarthritis Initiative (OAI) study. Trained on 34 MRIs with varying degrees of OA, the performance of the learning-based method tested on 108 MRIs showed a significant reduction in segmentation errors (\emph{p}$, Comment: IEEE Transactions in Medical Imaging, 11 pages

Objective: Osteophytes, also small ones, are an important imaging feature of OA. However, due to their high prevalence on MR, the question has arisen whether these are truly pathophysiologic features of early OA, a result of physiologic aging, or rather a merely transient phenomenon. The aim of this study was to explore the prevalence of osteophytes on MR in various locations of the knee, with special emphasis on small osteophytes, across multiple large studies conducted in our institution comprising a wide range of subjects at different ages. Method: Retrospective explorative study of the prevalence of osteophytes, particularly grade 1 according to MOAKS, among four studies with a wide variety in age and OA risk factors. Results: A large number of grade 1 osteophytes were found in all four studies. The largest number of osteophytes were present in the youngest age group of

The purpose of this study is to determine the association between polyethylene surface damage and the severity of frondlike hypertrophied synovitis, joint distention, capsular thickness, and osteolysis on MRI compared with other patient factors. Another goal of this study is to ascertain the interobserver reliability in MRI evaluation of synovitis.MR images of 61 patients who had undergone revision total knee arthroplasty (TKA) were retrospectively reviewed. The two MRI reviewers were blinded to clinical and retrieval data. The retrieved polyethylene tibial inserts were graded to determine the severity of surface damage. The association of MRI features with surface damage was assessed using Spearman correlation coefficients and multiple linear regression. Interobserver reliability was assessed using the kappa statistic.Correlations were moderate between the surface damage score and MRI synovitis severity (r = 0.46; p0.001) and joint distention (r = 0.41; p = 0.001). Multiple linear regression showed that the MRI synovitis score (p = 0.045), male sex (p = 0.007), body mass index (p = 0.041), and the time since implantation (p0.0001) predicted the surface damage score. Substantial interobserver agreement was shown for MRI grading of synovitis (κ = 0.72; 95% CI, 0.65-0.80).The magnitude of frondlike hypertrophied synovitis on MRI is significantly associated with polyethylene surface damage in patients who undergo revision TKA. The finding of severe frondlike synovitis on MR images of patients with TKA should raise the possibility of polyethylene surface damage. However, time since implantation is a stronger predictor of surface damage.

To compare diagnostic performance of a 5-min knee MRI protocol to that of a standard knee MRI. One hundred 3 T (100 patients, mean 38.8 years) and 50 1.5 T (46 patients, mean 46.4 years) MRIs, consisting of 5 fast, 2D multi-planar fast-spin-echo (FSE) sequences and five standard multiplanar FSE sequences, from two academic centers (1/2015–1/2016), were retrospectively reviewed by four musculoskeletal radiologists. Agreement between fast and standard (interprotocol agreement) and between standard (intraprotocol agreement) readings for meniscal, ligamentous, chondral, and bone pathology was compared for interchangeability. Frequency of major findings, sensitivity, and specificity was also tested for each protocol. Interprotocol agreement using fast MRI was similar to intraprotocol agreement with standard MRI (83.0–99.5%), with no excess disagreement (≤ 1.2; 95% CI, −4.2 to 3.8%), across all structures. Frequency of major findings (1.1–22.4% across structures) on fast and standard MRI was not significantly different (p ≥ 0.215), except more ACL tears on fast MRI (p = 0.021) and more cartilage defects on standard MRI (p

Rationale and Objectives The increasing availability of personal health portals has made it easier for patients to obtain their imaging results online. However, the radiology report typically is designed to communicate findings and recommendations to the referring clinician, and may contain many terms unfamiliar to lay readers. We sought to evaluate a web-based interface that presented reports of knee MRI (magnetic resonance imaging) examinations with annotations that included patient-oriented definitions, anatomic illustrations, and hyperlinks to additional information. Materials and Methods During a 7-month observational trial, a statement added to all knee MRI reports invited patients to view their annotated report online. We tracked the number of patients who opened their reports, the terms they hovered over to view definitions, and the time hovering over each term. Patients who accessed their annotated reports were invited to complete a survey. Results Of 1138 knee MRI examinations during the trial period, 185 patients (16.3%) opened their report in the viewing portal. Of those, 141 (76%) hovered over at least one term to view its definition, and 121 patients (65%) viewed a mean of 27.5 terms per examination and spent an average of 3.5 minutes viewing those terms. Of the 22 patients who completed the survey, 77% agreed that the definitions helped them understand the report and 91% stated that the illustrations were helpful. Conclusions A system that provided definitions and illustrations of the medical and technical terms in radiology reports has potential to improve patients' understanding of their reports and their diagnoses.