Lumbrical muscle enhancement on MRI and its association with rheumatoid arthritis.

OBJECTIVE: To investigate the significance of lumbrical muscle enhancement (LME) on magnetic resonance imaging (MRI) in rheumatoid arthritis (RA). MATERIALS AND METHODS: Blinded to the diagnoses, contrast-enhanced bilateral hand MRIs of patients with suspected early RA between 2014 and 2019 were reviewed by two observers for the presence and degree (weak/strong) of LME. The presence of other inflammatory findings was also noted. The patients were then stratified into RA (n = 41), control (n = 31), and other arthritides groups(n = 28) based on their final diagnoses in the hospital records within the following 12 months. Categorical variables were compared by chi-square test or Fisher's exact test. Differences among the groups were evaluated by one-way ANOVA or Kruskal-Wallis tests. When the p-value from the Kruskal-Wallis test was statistically significant, multiple comparison test was used to identify group differences. Correlations between LME and flexor tenosynovitis were evaluated by Spearman rank correlation test. The agreement between two observers was assessed by Cohen's Kappa (κ) statistic. P-value < 0.05 was considered as statistically significant. RESULTS: There were 100 patients (88 females) with mean age of 47.2 ± 11.2. There were no significant differences for age or sex between groups (p = 0.17, p = 0.84, respectively). RA patients showed significantly more frequent (p < 0.001) and stronger LME (p = 0.001). There were no correlations between LME and flexor tenosynovitis (p > 0.05). Interrater agreement for the degree of LME on right and left sides was substantial (κ = 0.74, κ = 0.67, respectively). CONCLUSION: RA patients demonstrated significantly more frequent and stronger LME with substantial interrater agreement. LME could constitute a subtle radiological clue for early RA.

Multifocal concomitant scapulothoracic and subgluteal-ischiofemoral elastofibromas.

PURPOSE: To evaluate the frequency, imaging findings, and patient demographics of synchronous elastofibroma dorsi (ED) and pelvic elastofibromas. METHODS: Image archives between 2011 and 2021 were retrospectively searched for CT and MRI reports including the keyword "elastofibroma". Patients with concomitant CT and/or MRI of the chest and pelvic regions were included. The greatest thickness and side of ED were noted. Subsequently, pelvic soft tissues were evaluated for a soft tissue mass with similar radiological features to ED. When detected, its location, greatest transverse diameter, and ischiofemoral space widths were noted. Wilcoxon matched-pairs signed-rank and Mann-Whitney U-tests were performed when appropriate. Pearson's correlations were used to assess the association of presence of subgluteal-ischiofemoral elastofibromas (SGIFE) and ED thickness. The model discrimination of ED thickness was evaluated by calculating the AUC of the ROC. RESULTS: Eighty-eight patients (Male:Female = 8:80) with a mean age of 70.6 (±10.3) years were included. 96.6 % of patients had bilateral ED. 18.2 % of patients (all females) had at least one concomitant SGIFE. Patients with SGIFE had significantly thicker ED (p < 0.001 right; p = 0.049 left). There was a significant positive correlation between the thickness of ED and presence of SGIFE (r = 0.43, p < 0.001 right; r = 0.25, p = 0.019 left). An AUC of 0.781 (p < 0.001, 95 %-CI:0.675-0.887) and 0.659 (p = 0.049, 95 %-CI:0.523-0.794) were revealed regarding the presence of ipsilateral right and left SGIFE, respectively. CONCLUSION: Concomitant SGIFE may accompany ED in up to 18.2% of cases, particularly in women with thick ED. Knowledge of this co-occurrence and the described SGIFE characteristics can facilitate correct diagnosis.

A new significance of an old structure: Aponeurotic expansion of supraspinatus tendon and its relationships with biceps brachii long head and rotator cuff tendons.

PURPOSE: To investigate the relationship between aponeurotic expansion of supraspinatus tendon and disorders of biceps brachii long head (LHB), supraspinatus and subscapularis tendons. METHODS: Images of 3.0 T shoulder magnetic resonance images (MRI) of a total of 154 patients and 157 shoulders (3 cases with bilateral imaging) between the ages of 18-45 were retrospectively evaluated for the presence of aponeurotic expansion. When identified it was further categorized according to its thickness. Tendinopathy and tears of LHB, supraspinatus and subscapularis tendons and LHB subluxations were evaluated individually. Statistical analyses were performed using Chi-square, Fisher's exact, Mann-Whitney U and Kruskall-Wallis tests. Odds ratio and multiple logistic regression analyses were performed when applicable. p < 0.05 was considered as statistically significant. RESULTS: A total of 82 male and 72 female cases with a mean age of 34 (±8.2) were included. Aponeurotic expansion could be identified in 31 cases (19.8 %). MRI findings for LHB disorders in this group was significantly higher (p = 0.01). The adjusted odds ratio of having LHB tendinopathy in the presence of aponeurotic expansion was 3.25 (% 95 CI:1.29-8.19). No significant correlation was found between presence of aponeurotic expansion and subscapularis or supraspinatus tendon disorders (p = 0.66 and p = 0.792 respectively). Age was a significant variable for disorders of all three tendons (p < 0.001). CONCLUSION: On 3.0 T MRI, findings of LHB tendon disorders were significantly more common in cases with aponeurotic expansion of supraspinatus tendon. This anatomical variation may have an unrecognized clinical significance.

Periosteal chondrosarcoma of the foot: a case report.

A 19-year-old girl presented with painless swelling of the first left toe of 6 years' duration. Magnetic resonance imaging (MRI) of the lesion demonstrated a soft tissue mass adjacent to the surface of the bone with slight erosion of the underlying cortex. Surgical excision was performed and the histopathological diagnosis was low-grade periosteal chondrosarcoma, which is quite uncommon in this location.

Assessment of peritrochanteric high T2 signal depending on the age and gender of the patients.

INTRODUCTION: The aim of this study is to evaluate the incidence of peritrochanteric high T2 signal (peritrochanteric edema, peritendinitis) on routine MR imaging studies and to determine whether reporting peritrochanteric edema is always clinically relevant depending on the age and gender of the patients. MATERIALS AND METHODS: We evaluated 79 consecutive bilateral hip MR images performed in our department between January 2006 and December 2006 (57 female, 22 male patients, mean age 49 years). Each study was evaluated for areas of T2 hyperintensity representing edema around the greater trochanter. Patients with a known fracture, tumor, history of radiation therapy, history of hip surgery and prothesis were excluded from the study. Patients with signal intensity alterations within the thickened gluteus medius/minimus tendons (tendinitis) or peritrochanteric bursal fluid accumulation (bursitis) were also excluded. All patients were scanned with our routine MR imaging protocol for hip imaging. RESULTS: In 55 of the 79 patients (70%) peritrochanteric edema was detected on MR images and 52 of these 55 patients (95%) had these changes on both hips. The median age was 56 years for the patients with peritrochanteric edema and 35.5 years for the patients without peritrochanteric edema. There was statistical significance between the median ages of the patients and a significant increased risk of peritrochanteric edema was found over 40 years of age. There was no significant difference between male and female patients. CONCLUSION: Bilateral peritrochanteric high T2 signal may be a part of the degeneration process and we suggest that it may not be necessarily reported if the clinical findings do not support greater trochanteric pain syndrome.

An overview of MR arthrography with emphasis on the current technique and applicational hints and tips.

Magnetic resonance (MR) arthrography has been investigated in every major peripheral joint of the body, and has been proven to be effective in determining the integrity of intraarticular ligamentous and fibrocartilaginous structures and in the detection or assessment of osteochondral lesions and loose bodies in selected cases. Several methods could be used to create arthrogram effect during MR imaging, however, direct MR arthrography using diluted gadolinium as the contrast agent is the most commonly used technique and is the most reliable of all. MR arthrography is useful for demonstrating labrocapsular-ligamentous abnormalities and distinguishing partial thickness rotator cuff tears from focal full thickness tears in the shoulder, identifying or excluding recurrent tears following meniscal operations in the knee, demonstrating perforations of the triangular fibrocartilage complex (TFCC) and ligaments in the wrist, showing labral tears in the hip, diagnosing ligament tears in the ankle and identifying osteochondral lesions or loose bodies in any of the aforementioned joints. In this article, an overview of techniques of MR arthrography is provided with emphasis on direct MR arthrography using diluted gadolinium as the contrast agent. The current applications of the technique in major peripheral joints are reviewed, with emphasis given to the shoulder joint where the role of this technique has become well established.

Virtual MR arthroscopy of the wrist joint: a new intraarticular perspective.

OBJECTIVE: The aim of this study is to investigate whether virtual MR arthroscopy could be used to visualize the internal architecture of the radiocarpal compartment of the wrist joint in comparison to surgical arthroscopy. DESIGN: Diluted paramagnetic contrast material was injected into the radiocarpal compartment prior to MR examination in all patients. A fat-suppressed T1-weighted three-dimensional fast spoiled gradient echo sequence was acquired in addition to our standard MR imaging protocol in each patient. Three-dimensional data sets were then transferred to an independent workstation and were postprocessed using navigator software to generate surface rendered virtual MR arthroscopic images. PATIENTS: Nineteen patients referred for chronic ulnar-sided wrist pain were evaluated with conventional MR arthrography prospectively. RESULTS AND CONCLUSION: Virtual MR arthroscopic images demonstrating the triangular fibrocartilage complex (TFCC) in an intraarticular perspective were achieved in 12 out of 19 patients. Our preliminary investigation suggests that although it has several limitations, virtual MR arthroscopy shows promise in visualizing the TFCC from an intraarticular perspective.

Neuroarthropathy of the extremities: magnetic resonance imaging features.

The objective of this article was to review the magnetic resonance imaging (MRI) findings of four different neuroarthropathic extremities, and discuss the role of MRI in establishing a correct diagnosis. The shoulder, ankle, and knee had predominantly atrophic neuroarthropathic changes, whereas both atrophic and productive changes could be seen in the elbow. Bone marrow edema, suggesting a recent stress fracture, was detected in the elbow and knee. Osteochondral defects, or "detritic" synovitis with effusion, were extensive in all joints but exceptionally profound in the shoulder with amputation-like osteolysis and a total loss of the humeral head. Radiologists may encounter the joint manifestations of neuropathy, which may be confused with various pathologies, including tumor and septic arthritis, before the neurological diagnosis is established. MRI is helpful in detecting the extension of the disease as well as to differentiate chronic Charcot's arthropathy from septic arthritis before radiographic findings suggest the diagnosis.