Comparison of 3T MR arthrography and 3T MRI in intra-articular hip pathology: a cost-analysis.

BACKGROUND: MR arthrography (MRA) has previously been the radiological gold standard for investigating labral and chondral lesions of the hip joint. In recent years, 3T MRI has demonstrated comparable accuracy, being adopted as the first-line imaging investigation in many institutions. AIMS: We compare the associated increased cost and radiation dose of the fluoroscopic component of the MRA compared to MRI. METHODS: In this retrospective review over 2 years, 120 patients (mean age 27.3 years ± 13.2, range 8-67) underwent 3T MRA or non-contrast 3T MRI. Three musculoskeletal radiologists reported the data independently. Primary objectives included cost-comparison between each and radiation dose of the fluoroscopic component of the MRA. Secondary objectives included comparing detection of pathology involving the acetabular labrum, femoral cartilage, and acetabular cartilage. RESULTS: Then, 58 (48%) underwent 3T MRA and 62 (52%) patients underwent 3T MRI. The added cost of the fluoroscopic injection prior to MRA was €116.31/patient, equating to €7211.22 savings/year. MRA was associated with a small radiation dose of 0.003 mSv. CONCLUSIONS: Transitioning from 3T MRA to 3T MRI in the investigation of intra-articular hip pathology increases cost savings and reduces radiation dose.

Are brake response times altered post CT-guided cervical spine nerve root injections?

OBJECTIVES: To assess if brake response times are altered pre and post CT-guided cervical spine nerve root injections. METHODS: Brake response times were assessed before and after CT-guided cervical spine nerve root injections in a cohort of patients. The average of 3 brake response times was recorded before and 30 min after injection. Statistical analysis was performed using GraphPad. A paired Student t-test was used to compare the times before and after the injections. RESULTS: Forty patients were included in this study. The mean age was 55 years. There were 17 male and 23 female patients. There was no significant difference in the mean pre and post CT-guided cervical spine nerve root injection brake response times; 0.94 s (range 0.4-1.2 s) and 0.93 s (range 0.5-1.25 s), respectively (P = .77). CONCLUSIONS: Brake response time did not significantly differ pre and 30 min post CT-guided cervical spine nerve root injections. ADVANCES IN KNOWLEDGE: To the authors' best knowledge, there are no current studies assessing brake response times post CT-guided cervical spine nerve root injections. While driving safety cannot be proven by a single metric, it is a useful study in demonstrating that this is not inhibited in a cohort of patients.

Imaging of acute lower limb muscle injury and potential gender differences.

OBJECTIVES: To assess the most common lower limb acute muscle injuries on MRI imaging in a national specialist centre for orthopaedics and sports medicine and to explore potential gender differences. METHODS: Over a 3-year time period, all MRI lower limb studies with acute muscle injury (AMI) were reviewed. A British Athletics muscle injury classification (BAMIC) was given and a statistical analysis was performed. RESULTS: A total of 195 AMIs were diagnosed: 177 (91%) male and 18 (9%) female injuries (M to F = 9.8:1). The most common lower limb AMIs were BAMIC grade 1a injuries (n = 48, 25%). The most commonly injured muscle was biceps femoris (n = 87, 45%), specifically grade 1b and grade 2b injuries. There was no significant difference in age between men and women with acute lower limb muscle injuries (p = 0.19). Females were 1.5 times more likely to have a lower grade AMI than males, although this did not reach statistical significance (p = 0.7) owing to a striking lower number of female patients. There was no significant difference between genders in the likelihood of sustaining a hamstring or quadricep AMI (hamstrings OR = 2.47, p = 0.14 and quadriceps OR = 0.926, p 0.99). CONCLUSIONS: Grade 1a is the most common lower limb AMI grade in our institution, accounting for 25%. Biceps femoris is the most commonly injured muscle (45%) with grade 1b and grade 2b being the most frequently encountered grades of biceps femoris injuries. Lower-grade injuries are more common in females compared to males, although not significantly so. Further studies are required to explore possible reasons for this gender gap.

The value of injectable viscoelastic supplements for joints.

Intra-articular viscoelastic supplements are commonly administered by musculoskeletal radiologists for the treatment of symptomatic osteoarthritis (OA). This article provides an overview of the putative mechanism of action of the agents, a brief review of the evidence base underlying the practice, a commentary on some of the major society guidelines regarding the treatment, and a description of the adverse events that are associated with intra-articular hyaluronic acid administration.

Denervation pseudo hypertrophy of the calf: An important cause of lower limb swelling.

Denervation pseudohypertrophy is an uncommon cause of limb swelling, which may be overlooked. It is an important diagnosis to arrive at, as it instructs the search for an underlying cause which may itself require intervention. We present the case of a 32-year-old male rugby player with a 2-year history of left calf swelling and intermittent pain and tightness. He described a previous history of 2 left sided lumbar micro-discectomy surgeries. There was no tenderness or sensory deficit on examination. MRI of the left calf revealed muscular enlargement, with fat interspersed between the muscle fibers, in keeping with pseudohypertrophy. This has a number of causes, in this cause attributed to lumbar radiculopathy. This case highlights a rare but important cause of limb swelling which should be considered in the workup of a unilateral swollen limb.

Complications in image-guided musculoskeletal injections.

OBJECTIVE: To establish the incidence and define the nature of complications occurring following image-guided musculoskeletal injections at our institution. MATERIALS AND METHODS: All patients undergoing image-guided musculoskeletal injection during the study period (16/3/2016 to 24/01/2020) were included. Departmental records were reviewed to identify all patients describing possible complications following injection, what therapy was required (if any) and what the outcome was. No patients were excluded. Complications were classified as minor or major. Injections were categorised as follows: cervical spine, lumbar facet joint, lumbar nerve root, caudal epidural and 'other'. The complication rate for each individual category of procedure was compared with the combined complication rate for all other categories by constructing contingency tables and using Fisher's exact test. RESULTS: A total of 8226 patients underwent image-guided musculoskeletal injections within the study period. Exactly 100 patients were identified as having reported a complication, producing an overall complication rate of 1.2%. One complication was categorised as 'major', with the patient requiring expedited surgery. The remainder (99 patients) were categorised as having experienced minor complications. The incidence of complications after 'other' injections was significantly greater than for other categories of injection (1.86%, p = 0.028). There was no significant difference in the complication rate for cervical spine (0.93%, p = 0.257), lumbar nerve root (0.85%, p = 0.401), lumbar facet joint (0.67%, p = 0.326) or caudal epidural (1.29%, p = 0.687) injections. 'Other' injections were subsequently further sub-categorised by anatomical site and imaging modality used. Glenohumeral (2.97%, p = 0.0361) and sacro-iliac (3.51%, p = 0.0498) joint injections were associated with a significantly increased risk of complications. There was no difference in the incidence of complications with fluoroscopic or ultrasound guidance. CONCLUSION: In conclusion, image-guided musculoskeletal injections are safe and well-tolerated procedures. Complications are rare, occurring in just 1.2% of patients. 99% of complications are minor, either not requiring intervention or resolving with simple supportive treatment.

Gaelic Sport Injuries.

The Gaelic sports of hurling and football, native to Ireland, are increasing in popularity worldwide. The injury profile of these sports requires multidisciplinary management by sports physicians, orthopaedic surgeons, and musculoskeletal (MSK) radiologists, among others. Advances in imaging modalities and interventional techniques have aided the diagnosis and treatment of sport injuries. In this article, we review the literature and our own institutional experience to describe common injury patterns identified in Gaelic games athletes, their main imaging features and relevant therapeutic interventions. We discuss the increasing prevalence of imaging services at sporting events and the central role of MSK radiologists in sports injury management.

Pigmented villonodular synovitis of the hip joint: Three cases demonstrating characteristic MRI features.

Pigmented villonodular synovitis is a rare benign proliferative disease of synovial membranes, causing villonodular synovial hyperplasia and hemosiderin deposition. Its intra-articular forms most commonly affect the knee and less commonly the hip. PVNS of the hip is most common in the second to fifth decades and presentation is typically with pain and occasionally joint dysfunction. We review the existing literature and demonstrate characteristic magnetic resonance imaging features of pigmented villonodular synovitis in the hip joint using three biopsy-proven cases, with the aims of increasing awareness and aiding diagnosis of this rare but potentially debilitating and progressive condition. Recognition of its clinical presentation, appropriate use of magnetic resonance imaging and identification of imaging characteristics are essential to guiding biopsy interpretation and treatment.

Perylene Bisimide Dyes with up to Five Independently Introduced Substituents: Controlling the Functionalization Pattern and Photophysical Properties Using Regiospecific Bay Substitution.

We report herein a versatile and user-friendly synthetic methodology based on sequential functionalization that enables the synthesis of previously unknown perylene bisimide (PBI) dyes with up to five different substituents attached to the perylene core (e.g., compound 15). The key to the success of our strategy is a highly efficient regiospecific 7-mono- and 7,12-di-phenoxy bay substitution at the "imide-activated" 7- and 12-bay positions of 1,6,7,12-tetrachloroperylene monoimide diester 1. The facile subsequent conversion of the diester groups into an imide group resulted in novel PBIs (e.g., compound 14) with two phenoxy substituents specifically at the 7- and 12-bay positions. This conversion led to the activation of C-1 and C-6 bay positions, and thereafter, the remaining two chlorine atoms were substituted to obtain tetraphenoxy-PBI (compound 15) that has two different imide and three different bay substituents. The methodology provides excellent control over the functionalization pattern, which enables the synthesis of various regioisomeric pairs bearing the same bay substituents. Another important feature of this strategy is the high sensitivity of HOMO-LUMO energies and photoinduced charge transfer toward sequential functionalization. As a result, systematic fluorescence on-off switching has been demonstrated upon subsequent substitution with the electron-donating 4-methoxyphenoxy substituent.

A 5-year review of a pitch side radiology unit at an international sports stadium.

BACKGROUND: The increased strength and conditioning of elite athletes has led to greater potential for high impact injuries. With increasing concerns for player welfare, the decision to return to play after sustaining an on-field injury is complex. AIM: Review of a 5-year experience of a pitch side radiology unit (PSRU) at a large international sports stadium. METHODS: X-rays were acquired in a purpose built pitch side radiology unit (PSRU) within a large international sports stadium (Aviva Stadium) using a mobile digital X-ray unit. All x-rays were performed at the Aviva stadium's PSRU from October 2012 to March 2018. RESULTS: From October 2012 to March 2018, 89 competitive sport matches were held at the international sports stadium. 43/89 (48%) matches required the PSRU, with rugby matches having the highest utilization rates (34/47, 72.3%). In 89 matches, a total of 79 x-rays were performed (0.89 x-rays/match). The highest percentage of sports players undergoing imaging was rugby players (70/79, 88.6%). Overall, the majority of x-rays were of the upper limbs (49/79, 62.0%) and lower limbs (25/79, 31.6%). 17/79 (21.5%) x-rays demonstrated an acute bony injury, 15/17 (88%) of which were rugby players. CONCLUSION: The PSRU at the Aviva international sports stadium is well utilized and allows for a rapid diagnosis of osseous injuries sustained on the field of play. It provides a useful adjunct to the pitch side clinical assessment by medical staff. It provides a privacy and strategic advantage to players compared with hospital-based services. Consideration should be given to installing similar PSRUs at major sports stadiums around the world.

Whole-body MRI of bone marrow: A review.

Technical advances in the last two decades have allowed rapid, high-resolution whole-body magnetic resonance imaging (WBMRI). MRI allows unparalleled visualization and detail in the imaging of bone marrow and surrounding soft tissues. The properties of nuclear magnetic resonance allow superb characterization of bone marrow constituents. WBMRI allows superb characterization of the different types of bone marrow and their natural evolution during the life cycle. Diffusion-weighted WBMRI is an exciting development that adds functional information to anatomical detail. The mainstay of WBMRI for bone marrow abnormalities to date has centered upon staging multiple myeloma and other hematologic bone marrow conditions, and as a valuable tool in quantifying skeletal metastases. Increasingly, WBMRI is being utilized in a variety of additional malignant and nonmalignant conditions. Due to the absence of ionizing radiation, WBMRI represents a valuable screening tool in areas such as malignant transformation in hereditary multifocal exostoses or for the development of ischemic marrow insult in at-risk patients. An additional novel area of use includes postmortem WBMRI for characterization of skeletal injuries. This article provides a state-of-the-art and current review of WBMRI of the bone marrow and highlights potential future areas of development. Level of Evidence: 5 Technical Efficacy Stage: 3 J. MAGN. RESON. IMAGING 2019. J. Magn. Reson. Imaging 2019;50:1687-1701.

Therapeutic Intervention in Musculoskeletal Radiology: Current Practice and Future Directions.

Over the last several decades, the volume and range of therapeutic musculoskeletal (MSK) interventions that radiologists can offer their patients has dramatically increased. With new materials and improving imaging modalities, as well as significant investment in research, the field of MSK interventional radiologic intervention will likely continue to expand. In this article, we summarize the range of interventions currently available to the MSK radiologist. We also seek to explore new and emerging techniques that may become commonplace in the near future while considering the challenges that may lie ahead in the field of MSK radiology.

Role of Musculoskeletal Radiology in Modern Sports Medicine.

Musculoskeletal radiology's role in the recent and continued evolution of sports medicine is an exciting and expanding one. In this article we explore a variety of the ways that musculoskeletal radiology contributes to current practices in modern sports medicine, discussing advances across a variety of imaging modalities in the care of both elite athletes and so-called weekend warriors. We describe the technical and ethical factors pertaining to image-guided therapeutic intervention in athletes and speculate on the potential for future developments in the role of imaging in deciding when an athlete may return to participation. We also explore the recent shift to the delivery of imaging facilities at sporting events and in stadiums.

Training in Musculoskeletal Radiology in Europe: Philosophy, Challenges, and Practical Implementation.

This article provides an overview of the philosophy, mechanisms, and difficulties involved in the establishment of integrated training programs in medicine, radiology, and specifically musculoskeletal radiology across the European Union.

Separating Thermodynamics from Kinetics-A New Understanding of the Transketolase Reaction.

Transketolase catalyzes asymmetric C-C bond formation of two highly polar compounds. Over the last 30 years, the reaction has unanimously been described in literature as irreversible because of the concomitant release of CO2 if using lithium hydroxypyruvate (LiHPA) as a substrate. Following the reaction over a longer period of time however, we have now found it to be initially kinetically controlled. Contrary to previous suggestions, for the non-natural conversion of synthetically more interesting apolar substrates, the complete change of active-site polarity is therefore not necessary. From docking studies it was revealed that water and hydrogen-bond networks are essential for substrate binding, thus allowing aliphatic aldehydes to be converted in the charged active site of transketolase.

Injectable Viscoelastic Supplements: A Review for Radiologists.

OBJECTIVE: Hyaluronic acid (HA) is increasingly used by musculoskeletal radiologists in the treatment of osteoarthritis (OA). Although the evidence base for its efficacy is controversial, it remains in common use. With initial evidence suggesting its efficacy in the knee, it is now offered for treating OA of the hip, ankle, and elsewhere. CONCLUSION: HA is available in a wide variety of preparations, which may vary in concentration and chemical composition. Clinicians offering intraarticular HA injection should be familiar with the common preparations available and the principal differences between them, its mechanism of action, and the profile of adverse effects associated with its use.

Sports-Related Groin Pain Secondary to Symphysis Pubis Disorders: Correlation Between MRI Findings and Outcome After Fluoroscopy-Guided Injection of Steroid and Local Anesthetic.

OBJECTIVE: The objective of our study was to correlate patterns of injury on preprocedural MRI with outcome after targeted fluoroscopy-guided steroid and local anesthetic injection of the symphysis pubis and its muscular attachments in a group of athletes with chronic groin pain. MATERIALS AND METHODS: Forty-five patients with chronic sports-related groin pain underwent MRI of the pelvis and a targeted fluoroscopy-guided symphyseal corticosteroid and local anesthetic injection. Preprocedural MRI was reviewed. The presence or absence of a "superior cleft" sign (i.e., rectus abdominis-adductor longus attachment microtearing), "secondary cleft" sign (i.e., short adductor [gracilis, adductor brevis, and pectineus muscles] attachment microtearing), osteitis pubis, and extrasymphyseal pelvic abnormalities was recorded. Patients were followed up a mean time of 23 months after the procedure, and outcome was recorded. Correlation was made between preprocedural MRI findings and outcome. RESULTS: Forty-two percent of the patients had an isolated superior cleft sign, 7% had an isolated secondary cleft sign, and 11% had isolated osteitis pubis. Thirty-one percent of patients had a more complex injury, and 9% had a normal symphysis pubis. Overall, 89% of the patients experienced an improvement in symptoms. The response was sustained after a minimum of 6 months in 58% of the patients. The presence of the superior cleft sign was more frequently associated with a complete recovery. CONCLUSION: Fluoroscopy-guided corticosteroid symphyseal injection is a safe and effective treatment of sports-related groin pain. It is more frequently associated with a complete recovery in patients who display an isolated superior cleft sign on MRI. MRI not only is useful in characterizing groin injuries but also may be helpful in predicting response to therapeutic injection.

Acetabular paralabral cyst causing compression of the sciatic nerve.

Acetabular paralabral cysts are common. They vary in their clinical presentation and may be asymptomatic or cause pain and restriction at the hip joint. In rare instances they may cause symptoms by compressing local neurovascular structures. We report a case of symptomatic compression of the sciatic nerve by a posteriorly displaced acetabular paralabral cyst.