MR Imaging of the Upper Limb: Pitfalls, Tricks, and Tips

The assessment of atlantoaxial joint involvement in patients with rheumatoid arthritis, results from an observational "real-life" study

Atlantoaxial joint is a possible affected site during rheumatoid arthritis (RA) and, in this work, we evaluated its occurrence and associated characteristics in a "real-life" cohort. By a medical records review study of RA patients longitudinally followed-up, the occurrence of severe atlantoaxial joint involvement was estimated (incidence proportion and incidence rate per 1000 person-years at risk). Regression analyses were also exploited to evaluate possible associated factors. Based on these findings, a prospective recruitment was performed to build a descriptive cross-sectional study in evaluating a subclinical atlantoaxial joint involvement in patients with the same clinical characteristics. Retrospectively, 717 patients (female 56.6%, age 64.7 ± 12.3 years) were studied. The incidence proportion of severe atlantoaxial joint involvement was 2.1% [1.5-2.5], occurring in 15 out of 717 patients, and identified by both MRI and CT scan. Considering over 3091 person-years, an incidence rate of 5.2 × 1000 [2.9-8.3] person-years was estimated. Regression analyses suggested that male gender, a longer disease duration, ACPA positivity and extra-articular manifestations resulted to be significantly associated with a severe atlantoaxial joint involvement. Given these findings, 30 asymptomatic patients were selected according to these clinical characteristics and underwent MRI of cervical spine. To date, almost 50% of these asymptomatic patients showed a subclinical atlantoaxial joint involvement. The occurrence of the severe atlantoaxial joint involvement in RA patients was estimated in a "real-life" setting. Male gender, ACPA positivity, long disease duration, and extra-articular manifestations could be associated with the severe atlantoaxial joint involvement in RA. MRI could provide a useful clinical tool to early evaluate the atlantoaxial joint involvement in RA, also in asymptomatic patients.

Inter- and Intra-Rater Reliability of Ultrasound Measurements of Superficial and Deep Fasciae Thickness in Upper Limb

Ultrasound (US) imaging is increasingly the most used tool to measure the thickness of superficial and deep fasciae, but there are still some doubts about its reliability in this type of measurement. The current study sets out to assess the inter-rater and intra-rater reliability of US measurements of superficial and deep fasciae thicknesses in the arm and forearm. The study involved two raters: the first (R1) is an expert in skeletal–muscle US imaging and, in particular, the US assessment of fasciae; the second (R2) is a radiologist resident with 1 year’s experience in skeletal–muscle US imaging. R2, not having specific competence in the US imaging of fasciae, was trained by R1. R1 took US images following the protocol by Pirri et al. 2021, and the US-recorded images were analyzed separately by the two raters in different sessions. Each rater measured both types of fasciae at different regions and levels of the arm and forearm. Intra- and inter-rater reliability was excellent for the deep fascia and good and excellent for the superficial fascia according to the different regions/levels (for example for the anterior region of the arm: deep fascia: Ant 1: ICC_2,2 = 0.95; 95% CI = 0.81–0.98; superficial fascia: Ant 1: ICC_2,2 = 0.85, 95% CI = 0.79–0.88). These findings confirm that US imaging is a reliable and cost-effective tool for evaluating both fasciae, superficial and deep.

Imaging of traumatic shoulder injuries – Understanding the surgeon’s perspective

Imaging plays a key role in the assessment and management of traumatic shoulder injuries, and it is important to understand how the imaging details help guide orthopedic surgeons in determining the role for surgical treatment. Imaging is also crucial in preoperative planning, the longitudinal assessment after surgery and the identification of complications after treatment. This review discusses the mechanisms of injury, key imaging findings, therapeutic options and associated complications for the most common shoulder injuries, tailored to the orthopedic surgeon’s perspective.

Diagnostic performance of DIXON sequences on low-field scanner for the evaluation of knee joint pathology

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).

The joint involvement in adult onset Still's disease is characterised by a peculiar magnetic resonance imaging and a specific transcriptomic profile

Adult onset Still's disease (AOSD) is a rare systemic autoinflammatory disease, characterised by fever, arthritis, and skin rash, and joint involvement is one of its clinical manifestations. The aims of this work were to assess joint involvement, to describe main patterns of involvement, and associated clinical characteristics. In this work, we aimed at assessing the joint involvement in AOSD by using MRI, to describe main patterns and associated clinical characteristics. In addition, we aimed at assessing the global transcriptomic profile of synovial tissues in AOSD to elucidate possible pathogenic pathways involved. We also evaluated the global transcriptomic profile of synovial tissues to elucidate possible pathogenic pathways involved in the disease. Thus, AOSD patients, who underwent to MRI exam on joints, were assessed to describe patterns of joint involvement and associated clinical characteristics. Some synovial tissues were collected for RNA-sequencing purposes. The most common MRI finding was the presence of synovitis on 60.5%, mainly in peripheral affected joints, with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. Bone oedema and MRI-bone erosions were reported on 34.9% and 25.6% MRI exams, respectively. Patients with MRI-bone erosions showed a higher prevalence of splenomegaly, a more frequent chronic disease course, lower levels of erythrocyte sedimentation rate, and ferritin. In AOSD synovial tissues, a hyper-expression of interleukin (IL)-1, IL-6, and TNF pathways was shown together with ferritin genes. In conclusion, in AOSD patients, the most common MRI-finding was the presence of synovitis, characterised by intermediate to high signal intensity on T2-fat-saturated weighted and STIR images. MRI-bone erosions and bone oedema were also observed. In AOSD synovial tissues, IL-1, IL-6, and TNF pathways together with ferritin genes resulted to be hyper-expressed.

Multimodality Pitfalls of Wrist Imaging With a Focus on Magnetic Resonance Imaging: What the Radiologist Needs to Know

Numerous pitfalls are frequently encountered at multimodality imaging of the wrist, which may mimic various tendinous, osseous, capsuloligamentous, muscular, and neurovascular pathologic conditions. These pitfalls may be secondary to variant anatomy, artifactual due to magnetic resonance imaging or sonographic technique, or represent varying ranges of structure-specific normal including a spectrum of findings associated with aging in asymptomatic subjects. When an imaging finding of questionable significance is encountered, it is critical that the interpreting radiologist make every attempt to review any relevant clinical information in an effort to determine whether the imaging findings in question may account for the patient's presenting symptomology. In order to accurately diagnose true pathology at wrist imaging, it is imperative that the radiologist be familiar with the pitfalls discussed throughout this manuscript that may mimic disease. This familiarity will allow the radiologist to provide a more useful report for referring providers focusing on true pathology while eliminating potentially confusing or misleading findings which are inconsistent with the patient's clinical presentation.

Imaging of Acute Shoulder Trauma

Acute injuries to the shoulder girdle are common and frequently encountered by the practicing radiologist. The type of injury is highly dependent on the age of the patient and mechanism of trauma with injuries occurring at the site of greatest mechanical weakness. In this review, we discuss the main clinical features and key imaging findings for the most common shoulder injuries. For each injury, we also provide a section on the important features that the orthopedic surgeon needs to know in order to guide surgical versus nonsurgical management.