A perspective on the evolution of semi-quantitative MRI assessment of osteoarthritis: Past, present and future.

OBJECTIVE: This perspective describes the evolution of semi-quantitative (SQ) magnetic resonance imaging (MRI) in characterizing structural tissue pathologies in osteoarthritis (OA) imaging research over the last 30 years. METHODS: Authors selected representative articles from a PubMed search to illustrate key steps in SQ MRI development, validation, and application. Topics include main scoring systems, reading techniques, responsiveness, reliability, technical considerations, and potential impact of artificial intelligence (AI). RESULTS: Based on original research published between 1993 and 2023, this article introduces available scoring systems, including but not limited to Whole-Organ Magnetic Resonance Imaging Score (WORMS) as the first system for whole-organ assessment of the knee and the now commonly used MRI Osteoarthritis Knee Score (MOAKS) instrument. Specific systems for distinct OA subtypes or applications have been developed as well as MRI scoring instruments for other joints such as the hip, the fingers or thumb base. SQ assessment has proven to be valid, reliable, and responsive, aiding OA investigators in understanding the natural history of the disease and helping to detect response to treatment. AI may aid phenotypic characterization in the future. SQ MRI assessment's role is increasing in eligibility and safety evaluation in knee OA clinical trials. CONCLUSIONS: Evidence supports the validity, reliability, and responsiveness of SQ MRI assessment in understanding structural aspects of disease onset and progression. SQ scoring has helped explain associations between structural tissue damage and clinical manifestations, as well as disease progression. While AI may support human readers to more efficiently perform SQ assessment in the future, its current application in clinical trials still requires validation and regulatory approval.

Emerging Quantitative Imaging Techniques in Sports Medicine.

This article describes recent advances in quantitative imaging of musculoskeletal extremity sports injuries, citing the existing literature evidence and what additional evidence is needed to make such techniques applicable to clinical practice. Compositional and functional MRI techniques including T2 mapping, diffusion tensor imaging, and sodium imaging as well as contrast-enhanced US have been applied to quantify pathophysiologic processes and biochemical compositions of muscles, tendons, ligaments, and cartilage. Dual-energy and/or spectral CT has shown potential, particularly for the evaluation of osseous and ligamentous injury (eg, creation of quantitative bone marrow edema maps), which is not possible with standard single-energy CT. Recent advances in US technology such as shear-wave elastography or US tissue characterization as well as MR elastography enable the quantification of mechanical, elastic, and physical properties of tissues in muscle and tendon injuries. The future role of novel imaging techniques such as photon-counting CT remains to be established. Eventual prediction of return to play (ie, the time needed for the injury to heal sufficiently so that the athlete can get back to playing their sport) and estimation of risk of repeat injury is desirable to help guide sports physicians in the treatment of their patients. Additional values of quantitative analyses, as opposed to routine qualitative analyses, still must be established using prospective longitudinal studies with larger sample sizes.

Three-dimensional turbo spin-echo (TSE) MRI assessment of indirect acute muscle injuries in athletes: comparison with two-dimensional TSE MRI.

OBJECTIVE: To evaluate three-dimensional (3D) turbo spin-echo (TSE) magnetic resonance imaging (MRI) for the assessment of acute muscle injuries in elite athletes in comparison with two-dimensional (2D) MRI. METHODS: Elite athletes with clinically suspected acute muscle injury of the thigh who underwent both 2D and 3D MRI protocols on the same day were retrospectively included. Two musculoskeletal radiologists independently assessed 2D and 3D MRIs, with both techniques evaluated separately 1-month apart. Muscle injuries were evaluated using the BAMIC and the INSEP classifications. A second assessment of injuries was performed by each reader 2 months after the initial readings. Agreement was determined using weighted kappa statistics. The level of diagnostic confidence in classifying injuries was also assessed for both MRI protocols. RESULTS: A total of 40 athletes were included. Intra-reader agreement when comparing injury grades from 2D vs. 3D for both INSEP and BAMIC classifications was almost perfect for both readers and ranged between 0.84 and 0.98. Inter-reader agreement was substantial to almost perfect and ranged from 0.78 to 0.93 for the 2D protocol, and from 0.78 to 0.95 for the 3D protocol. Intra-reader agreement for each MRI protocol separately was almost perfect to perfect for both readers and ranged between 0.84 and 1.00. Diagnostic confidence for grading injuries improved for both readers when using the 3D protocol. CONCLUSIONS: Compared to 2D MRI, 3D TSE MRI is a reliable technique for acute muscular injury assessment, providing faster acquisition times and improving the diagnostic confidence. KEY POINTS: • Compared to 2D MRI, 3D TSE MRI is a reliable technique for the assessment of acute muscular injuries. • 3D TSE MRI has the advantage of faster total acquisition times, thinner sections, and multiplanar reconstruction, improving the confidence for structural assessment including connective tissue involvement.

Joint interventions in osteoarthritis.

Osteoarthritis (OA) is among the most common diseases affecting both axial and appendicular joints and the lead cause of disability worldwide. OA incidence is rising due to extended life expectancy and the increasing obesity epidemic. Several joint interventions are available to manage pain and joint function in patients with OA, most of these treatments being widely applied using intra-articular injections. In this chapter, we will describe the different joint interventions available for the management of pain in OA focusing on intra-articular injections, including discussion on the evidence regarding the efficacy of these treatments, based on the most recent systematic reviews and meta-analyses available. We also discuss the importance of imaging in guiding these treatments, including the different imaging modalities available for intra-articular injection guidance, their advantages, and disadvantages. Finally, we briefly discuss safety data and the consensus regarding the most used intra-articular treatments to manage pain in OA.

Imaging of muscle injuries in soccer.

Accurate diagnosis of muscle injuries is a challenge in everyday clinical practice and may have profound impact on the recovery and return-to-play decisions of professional athletes particularly in soccer. Imaging techniques such as ultrasound and magnetic resonance imaging (MRI), in addition to the medical history and clinical examination, make a significant contribution to the timely structural assessment of muscle injuries. The severity of a muscle injury determined by imaging findings has a decisive influence on therapy planning and affects prognosis. Imaging is of high importance when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be needed. This narrative review will discuss ultrasound and MRI for the assessment of sports-related muscle injuries in the context of soccer, including advanced imaging techniques, with the focus on the clinical relevance of imaging findings for the prediction of return to play.

Improved detection of subchondral erosions in the sacroiliac joints with T1-weighted fat-suppressed MRI.

OBJECTIVE: To compare the diagnostic performance of two different sets of magnetic resonance imaging (MRI) for the detection of subchondral erosions in the sacroiliac joints regarding the application of fat-water separation techniques when acquiring T1-weighted (T1w) images, using multi-detector computed tomography (MDCT) as the reference standard. METHODS: We retrospectively included 31 consecutive patients having or being suspected for axial spondyloarthritis (SpA) assessed using both MRI and MDCT. Three sets of images were independently assessed for the presence of erosions by two musculoskeletal radiologists (R1, R2): (1) MRI with standard T1w without fat suppression, (2) MRI with both T1w with and without fat suppression, and (3) MDCT. The diagnostic performance of both sets of MRIs was assessed using MDCT as the referent. RESULTS: The assessment of T1w images with fat suppression substantially increased sensitivity (76% vs. 63% R1; 70% vs. 60% R2), specificity (97% vs. 84% R1; 96% vs. 81% R2), positive predictive value (85% vs. 45% R1; 81% vs. 40% R2), and overall accuracy (94% vs. 80% R1; 92% vs. 77% R2) in the detection of erosions when compared to the assessment using T1w images without fat suppression. CONCLUSION: The assessment of T1w images with fat suppression substantially improves the diagnostic performance of MRI in the detection of erosions in the sacroiliac joints. KEY POINTS: • The presence of erosions in the sacroiliac joints may influence the decision on the diagnosis of axial spondyloarthritis. • T1w fat-suppressed MR imaging relatively increases the contrast between the joint space (high signal) and the adjacent subchondral bone (low signal), potentially improving the detection of erosions in the sacroiliac joints. • T1w fat-suppressed images improve the diagnostic performance of MRI in the detection of erosions in the sacroiliac joints compared to T1w without fat suppression, using MDCT as the reference.

Sports injuries at the Rio de Janeiro 2016 Summer Paralympic Games: use of diagnostic imaging services.

OBJECTIVE: To describe the occurrence of imaging-depicted sports-related injuries (bone, muscle, tendon, and ligament injuries) during the Rio 2016 Summer Paralympic Games. METHODS: Descriptive data on all imaging examinations by using radiography, ultrasonography (US), and MRI were collected and retrospectively analyzed centrally by five musculoskeletal radiologists according to imaging modality, country of origin of the athletes, type of sport, type of disability, and type and location of injury. RESULTS: We report 109 injuries in 4378 athletes. A total of 382 radiologic examinations were performed in 261 athletes, including 118 (31%) radiographic, 22 (6%) US, and 242 (63%) MRI examinations. Para athletes from Africa had the highest utilization rate (20.1%, 67 out of 333). Athletes from Europe underwent the most examinations with 29 radiographic, 12 US, and 66 MRI examinations. The highest utilization rate of imaging modalities by sport was among Judo para athletes (16.7%, 22 out of 132). Most injuries were reported in athletics discipline (37.6%, 41 out of 109). Most injuries were also reported among para athletes with visual impairment (40 injuries, 36.7% of all injuries). Bone stress injuries were most common among para athletes with visual impairment (6 out of 7). Para athletes with visual impairment were also more prone to bone stress injuries than traumatic fractures, unlike para athletes with neurologic and musculoskeletal impairments. CONCLUSIONS: Imaging was used in 6.0% of para athletes. MRI comprised 63% of imaging utilization. Identification of patterns of injuries may help building future prevention programs in elite para athletes. KEY POINTS: • The highest imaging utilization rates were found among para athletes competing in Judo, sitting volleyball, powerlifting, and football. • Utilization of diagnostic imaging at the Rio 2016 Paralympic Games demonstrated similar trends to what was observed at the Rio 2016 Olympic Games. • Comparison of the rate of imaging-depicted injuries between Olympic and Paralympic athletes is limited due to inherent differences between the two athlete populations and the manner in which injury risk in the Paralympic athlete varies dependent on impairment type, which is not the case for the Olympic athlete.

State of the Art: Imaging of Osteoarthritis-Revisited 2020.

Osteoarthritis (OA) is a highly prevalent chronic condition with marked implications for affected individuals and public health care. There are available treatments to manage pain and symptoms but no effective treatment for OA. In the past 10 years, joint imaging, particularly MRI, has evolved rapidly due to technical advances and their application to clinical research, which has led to abundant evidence regarding the natural history of the disease. Radiography remains the primary imaging modality in clinical practice for the diagnosis and follow-up of OA. The many developments in MRI techniques capable of assessing cartilage morphologic features and the methods for evaluating its biochemical composition will be discussed. Advances in quantitative morphologic cartilage assessment and semiquantitative whole-organ assessment will be reviewed, as will other modalities such as US, CT and CT arthrography, and nuclear medicine techniques that play a complementary role. Various therapeutic approaches and ongoing developments, including the impact of artificial intelligence on the field of OA imaging, will also be discussed.

Absence of pain in subjects with advanced radiographic knee osteoarthritis.

BACKGROUND: To investigate the frequency of pain among subjects with advanced radiographic knee osteoarthritis (OA) defined as Kellgren-Lawrence (KL) grade 4 and clinical features associated with pain. METHODS: Subjects from the Hallym Aging Study (HAS), the Korean National Health and Nutrition Examination Survey (KNHANES), and the Osteoarthritis Initiative (OAI) were included. Participants were asked knee-specific questions regarding the presence of knee pain. Clinical characteristics associated with the presence of pain were evaluated with multivariable logistic regression analysis. RESULTS: The study population consisted of 504, 10,152 and 4796 subjects from HAS, KNHANES, and OAI, respectively. KL grade 4 OA was identified in 9.3, 7.6, and 11.5% of subjects, while pain was absent in 23.5, 31.2, and 5.9% of subjects in KL grade 4 knee OA, respectively. After multivariable analysis, female gender showed a significant association with pain in the KNHANES group, while in the OAI group, younger age did. Advanced knee OA patients without pain did not differ from non-OA subjects in most items of SF-12 in both Korean and OAI subjects. Total WOMAC score was not significantly different between non-OA and advanced knee OA subjects without pain in the OAI. CONCLUSIONS: Our study showed that a considerable number of subjects with KL grade 4 OA did not report pain. In patients whose pain arises from causes other than structural damage of the joint, therapeutic decision based on knee X-ray would lead to suboptimal result. In addition, treatment options focusing solely on cartilage engineering, should be viewed with caution.

MRI-detected spinal disc degenerative changes in athletes participating in the Rio de Janeiro 2016 Summer Olympics games.

OBJECTIVE: To describe the frequency and the distribution of degenerative disc disease (DDD) detected in athletes who underwent spine MRI in the 2016 Summer Olympic Games in Rio de Janeiro. METHODS: Data on spine MRI examinations from the 2016 Summer Olympics were retrospectively analyzed. We assessed the frequency of DDD of the cervical (Cs), thoracic (Ts), and lumbar (Ls) spine using Pfirrmann's classification. Grade II and III were considered as mild, grade IV as moderate, and grade V as severe disc degeneration. Data were analyzed according to the location of the degenerative disc, type of sport, age-groups, and gender of the athletes. RESULTS: One hundred out of 11,274 athletes underwent 108 spine MRI's (21 C, 6 T, and 81 L) (53% Females (F), 47% Males (M)). The frequency of DDD was 40% (42% F, 58% M) over the entire spine (28% mild, 9% moderate and 3% severe). There were 58% (12%F, 88%M) of the cervical spine discs that showed some degree of degeneration (44% mild, 13.5% moderate and 1% severe). Athletics, Boxing, and Swimming were the sports most affected by DDD in the Cs. There were 12.5% of the thoracic discs that showed some degree of degeneration, all were mild DDD and were exclusively seen in female athletes. There were 39% (53% F, 47% M) of the lumbar discs with DDD (26% mild, 9% moderate, and 4% severe). CONCLUSION: Athletes who underwent spine MRI during the 2016 Summer Olympic Games show a high frequency of DDD of cervical and lumbar spines. Recognition of these conditions is important to develop training techniques that may minimize the development of degenerative pathology of the spine.

Intra-articular Corticosteroid Injections in the Hip and Knee: Perhaps Not as Safe as We Thought?

Osteoarthritis (OA) of the hip and knee is among the most common joint disorders. Intra-articular corticosteroid (IACS) injections are frequently performed to treat OA and other joint-related pain syndromes; however, there is conflicting evidence on their potential benefit. There is a lack of prospective and large retrospective studies evaluating potential joint findings, including increased risk for accelerated OA progression or adverse joint events, after treatment with IACS injection. Four main adverse joint findings have been structurally observed in patients after IACS injections: accelerated OA progression, subchondral insufficiency fracture, complications of osteonecrosis, and rapid joint destruction, including bone loss. Physicians, including radiologists, should be familiar with imaging findings and patient characteristics that may help them identify potential joints at risk for such events. The purpose of this report is to review the existing literature, describe observed adverse joint events after IACS injections, and provide an outlook on how this may affect clinical practice. Additional research endeavors are urgently needed to better understand and identify risk factors prior to intervention and to detect adverse joint events after injection as early as possible to prevent or minimize complications.

MRI of ankle sprain: the association between joint effusion and structural injury severity in a large cohort of athletes.

OBJECTIVE: To test the hypothesis if presence and amount of effusion in the tibiotalar and talocalcaneal joints are associated with an increased risk for severe structural injury in ankle sprains. METHODS: A total of 261 athletes sustaining acute ankle sprains were assessed on MRI for the presence and the amount of joint effusion in the tibiotalar and talocalcaneal joints, as well as for ligamentous and osteochondral injury. Specific patterns of injury severity were defined based on lateral collateral ligament, syndesmotic, and talar osteochondral involvement. The presence and the amount effusion (grades 1 and 2) were considered as risk factors for severe injury, while physiological amount of fluid (grade 0) was considered as the referent. Conditional logistic regression was used to assess the risk for associated severe injuries (syndesmotic ligament rupture and talar osteochondral lesions) based on the presence and amount of tibiotalar and talocalcaneal effusions. RESULTS: For ankles exhibiting large (grade 2) effusion in the tibiotalar joint (without concomitant grade 2 effusion in the talocalcaneal joint), the risk for partial or complete syndesmotic ligament rupture was increased more than eightfold (adjusted odds ratio 8.7 (95% confidence intervals 3.7-20.7); p < 0.001). The presence of any degree of effusion in any of the joints was associated with an increased risk for severe talar osteochondral involvement (several odds ratio values reported; p < 0.001), including large subchondral contusions and any acute osteochondral lesion. CONCLUSION: The presence of tibiotalar and talocalcaneal effusions is associated with an increased risk for severe concomitant structural injury in acute ankle sprains. KEY POINTS: • For ankles exhibiting severe (grade 2) effusion in the tibiotalar joint after sprain, the risk for partial or complete syndesmotic ligament rupture increases more than eightfold. • The presence of effusion in both tibiotalar and talocalcaneal joints is associated with an increased risk for severe ligament injury such as complete ATFL rupture as well as partial or complete syndesmotic ligament rupture. • The presence of effusion in the tibiotalar or talocalcaneal joints after sprain is associated with an increased risk for severe talar osteochondral involvement.

Sports Injuries at the Rio de Janeiro 2016 Summer Olympics: Use of Diagnostic Imaging Services.

Purpose To describe the occurrence of imaging-depicted sports-related stress injuries, fractures, and muscle and tendon disorders during the 2016 Summer Olympic Games in Rio de Janeiro, Brazil. Materials and Methods Data on radiologic examinations were collected and retrospectively analyzed centrally by two board-certified musculoskeletal radiologists (with a third musculoskeletal radiologist acting as an adjudicator in case of discrepancies). Descriptive data on all imaging examinations by using radiography, ultrasonography (US), and magnetic resonance (MR) imaging were collected and analyzed according to imaging modality, country of origin of the athletes, type of sport, and type and location of injury. Results There were 1101 injuries that occurred in 11 274 (9.8%) athletes. A total of 1015 radiologic examinations were performed, including 304 (30.0%) radiographic, 104 (10.2%) US, and 607 (59.8%) MR examinations. Excluding 10 athletes categorized as refugees, athletes from Africa had the highest utilization rate (14.8%, 148 of 1001). Athletes from Europe underwent the most examinations with 103 radiographic, 39 US, and 254 MR examinations. Gymnastics (artistic) had the highest percentage of athletes who underwent imaging (15.5%, 30 of 194). Athletics (track and field) had the most examinations (293, including 53 radiographic, 50 US, and 190 MR examinations). Conclusion The overall occurrence of imaging used to help diagnose sports-related injuries at the Rio de Janeiro 2016 Summer Olympics was 6.4% of athletes. In these cases, MR imaging comprised 60% of imaging utilization. © RSNA, 2018 Online supplemental material is available for this article.

MRI-Detected Sports-Related Knee Injuries and Abnormalities at the Rio de Janeiro 2016 Summer Olympic Games.

OBJECTIVE: The purpose of this article is to describe knee abnormalities and the occurrence of MRI-detected sports-related knee abnormalities by evaluating MRI examinations performed during the Rio de Janeiro Olympic Games held in August 2016. CONCLUSION: There were 11,274 athletes at the Rio 2016 Olympic Games, and 113 of them underwent at least one knee MRI in the Olympic Village. Cartilage abnormalities, followed by meniscal tears and ligament sprains, were the most frequent abnormalities.

The epidemiology of MRI detected shoulder injuries in athletes participating in the Rio de Janeiro 2016 Summer Olympics.

BACKGROUND: To use Magnetic Resonance Imaging (MRI) to characterize the severity, location, prevalence, and demographics of shoulder injuries in athletes at the Rio de Janeiro 2016 Summer Olympic Games. METHODS: This was a retrospective analysis of all routine shoulder MRIs obtained from the Olympic Village Polyclinic during the Rio 2016 Summer Olympics. Imaging was performed on 1.5 T and 3 T MRI, and interpretation was centrally performed by a board-certified musculoskeletal radiologist. Images were assessed for tendon, muscle, bone, bursal, joint capsule, labral, and chondral abnormality. RESULTS: A total of 11,274 athletes participated in the Games, of which 55 (5%) were referred for a routine shoulder MRI. Fifty-three (96%) had at least two abnormal findings. Seven (13%) had evidence of an acute or chronic anterior shoulder dislocation. Forty-nine (89%) had a rotator cuff partial tear and / or tendinosis. Subacromial / subdeltoid bursitis was present in 29 (40%). Thirty (55%) had a tear of the superior labrum anterior posterior (SLAP). CONCLUSION: Our study demonstrated a high prevalence of both acute and chronic shoulder injuries in the Olympic athletes receiving shoulder MRI. The high rates of bursal, rotator cuff, and labral pathology found in these patients implies that some degree of glenohumeral instability and impingement is occurring, likely due to fatigue and overuse of the dynamic stabilizers. Future studies are needed to better evaluate sport-specific trends of injury.

MDCT arthrography assessment of scaphoid nonunion advanced collapse: distribution of cartilage damage and relationship with scaphoid nonunion features.

OBJECTIVES: Our primary aim was to evaluate the distribution and severity of cartilage damage in a sample of patients with scaphoid nonunion advanced collapse (SNAC), assessed on MDCT arthrography, with regard to two well-known SNAC staging systems. Secondarily, we wanted to see if the degree of cartilage damage varied with the location of the nonunion. METHODS: We retrospectively included 35 patients with a history of SNAC who had undergone MDCT arthrography. The location of the fracture was defined as the proximal, middle, or distal third of the scaphoid. Cartilage damage was assessed in 14 distinct regions of the wrist using a modified Whole-Organ Magnetic Resonance Imaging Score (WORMS) system. Staging of SNAC for each patient was based on the distribution of cartilage damage seen on MDCT arthrography. The one-way ANOVA test was used to evaluate whether global cartilage damage scores differed between patients with proximal vs middle and distal nonunion. RESULTS: The radial styloid-scaphoid (85.7%), the scaphoid-trapezium-trapezoid (60%), the scapho-capitate (57.1%), and the proximal radio-scaphoid joints (42.9%) were most commonly affected by degenerative cartilage damage. A substantial number of patients could not be classified according to the two SNAC staging systems. Patients with proximal nonunion exhibited a higher mean score of global cartilage damage than patients with middle or distal nonunion: 14.3 ± 9.5 (95% CI 9.8, 18.7) vs 8.6 ± 6.9 (95% CI 4.7, 12.4); p < 0.0001. CONCLUSION: The distribution of cartilage damage does not always follow the pattern of progressive osteoarthritis widely described in SNAC. Proximal scaphoid nonunion is related to greater severity of global cartilage damage.

Magnetic resonance imaging-based morphological and alignment assessment of the patellofemoral joint and its relationship to proximal patellar tendinopathy.

OBJECTIVE: To assess the differences in morphology and alignment of the knee between patients with proximal patellar tendinopathy (PPT) and a control group, using MRI and focusing on the patellofemoral joint. METHODS: We retrospectively included 35 patients with clinically diagnosed and unequivocal findings of PPT on knee MRI, the case group. For the control group, we included 70 patients who underwent knee MRI for other reasons, with no clinical or MRI evidence of PPT. Patients and controls were matched for age and gender, with all subjects reporting frequent physical activity. MRIs were evaluated by two musculoskeletal radiologists, who assessed parameters of patellar morphology, trochlear morphology, patellofemoral alignment, and tibiofemoral alignment. The differences in parameters between cases and controls were assessed using Student's t test. Logistic regression was applied to assess the associations between the MRI parameters and the presence of PPT. RESULTS: The patellar height Insall-Salvati ratio was different between cases and controls (1.37 ± 0.21 vs. 1.24 ± 0.19; p = 0.003). The subchondral Wiberg angle was higher in cases than controls (136.8 ± 7.4 vs. 131.7 ± 8.8; p = 0.004). After applying logistic regression, significant associations with PPT were found [odds ratios (95% CI)] for patellar morphology [1.1 (1.0, 1.2)] and patellar height [1.3 (1.0, 1.7)]. CONCLUSIONS: Patellar height and the subchondral patellar Wiberg angle were greater in patients with PPT and significantly associated with PPT.

Epidemiology of imaging-detected tendon abnormalities in athletes participating in the Rio de Janeiro 2016 Summer Olympics.

BACKGROUND: Tendon abnormalities are prevalent among both elite and non-elite athletes. Cross-sectional imaging modalities are used to confirm and evaluate the severity of such lesions. AIM: To describe the demographics, prevalence, anatomical location and characteristics of tendon abnormalities in athletes who participated in the Rio de Janeiro 2016 Summer Olympic Games. METHODS: We recorded all sports injuries reported by the National Olympic Committee (NOC) medical teams and the Organizing Committee medical staff during the Rio 2016 Summer Olympics. Diagnostic imaging was performed through the official IOC clinic within the Olympic Village, using digital ultrasound machines and 3T and 1.5T MR scanners. Image interpretation was performed centrally by board-certified musculoskeletal radiologists with expertise in sports injuries. RESULTS: In total, 11 274 athletes (5089 women (45%), 6185 men (55%)) from 207 NOCs were included. NOC and Rio de Janeiro 2016 medical staff reported 1101 injuries. Central review of radiological images revealed 156 tendon abnormalities in 109 athletes (51.2% male, mean age: 26.8, range 18-39). The supraspinatus tendon was the most commonly involved tendon (31 cases, 19.9%), followed by the Achilles tendon (20 cases, 12.8%) and patellar and infraspinatus tendons (12 cases, 7.7%). Tendon abnormalities were most commonly seen in track and field athletes (54 abnormalities, 34.6%). CONCLUSION: 156 tendon abnormalities were reported, most commonly in track and field athletes, and involving mainly the shoulder tendons, as well as Achilles and patellar tendons.

Imaging-detected acute muscle injuries in athletes participating in the Rio de Janeiro 2016 Summer Olympic Games.

BACKGROUND: Acute muscle injuries in elite athletes are responsible for a large portion of time loss injuries. AIM: To describe the frequency, the anatomic distribution, and severity of imaging-detected acute muscle injuries among athletes who competed in the Rio de Janeiro 2016 Summer Olympics. METHODS: We recorded all sports injuries reported by the National Olympic Committee medical teams and the Organising Committee medical staff during the 2016 Summer Olympics. Imaging of acute muscle injuries was performed at the IOC's polyclinic within the Olympic Village using ultrasound and 3.0 T and 1.5 T MRI scanners. The assessment of images was performed centrally by three musculoskeletal radiologists. The distribution of injuries by anatomic location and sports discipline and the severity of injuries were recorded. RESULTS: In total, 11 274 athletes from 207 teams were included. A total of 1101 injuries were reported. Central review of radiological images revealed 81 acute muscle injuries in 77 athletes (66% male, mean age: 25.4 years, range 18-38 years). Athletics (track and field) athletes were the most commonly affected (n=39, 48%), followed by football players (n=9, 11%). The majority of injuries affected muscles from lower limbs (n=68, 84%), with the hamstring being the most commonly involved. Most injuries were grade 2 injuries according to the Peetrons classification (n=44, 54%), and we found 18 injuries exhibiting intramuscular tendon involvement on MRI. CONCLUSION: Imaging-detected acute muscle injuries during the 2016 Summer Olympics affected mainly thigh muscles in athletics disciplines.

Imaging of Muscle Injuries in Sports Medicine: Sports Imaging Series.

In sports-related muscle injuries, the main goal of the sports medicine physician is to return the athlete to competition-balanced against the need to prevent the injury from worsening or recurring. Prognosis based on the available clinical and imaging information is crucial. Imaging is crucial to confirm and assess the extent of sports-related muscle injuries and may help to guide management, which directly affects the prognosis. This is especially important when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be necessary. Several imaging techniques are widely available, with ultrasonography and magnetic resonance imaging currently the most frequently applied in sports medicine. This state of the art review will discuss the main imaging modalities for the assessment of sports-related muscle injuries, including advanced imaging techniques, with the focus on the clinical relevance of imaging features of muscle injuries. © RSNA, 2017 Online supplemental material is available for this article.