Imaging features of gluteal in vitro fertilization injection granulomas, with delayed clinical presentation simulating soft tissue sarcoma.

OBJECTIVES: To review the clinical and imaging findings of patients with remote history of intramuscular (IM) in vitro fertilization (IVF) gluteal injections, presenting with signs and symptoms of a possible gluteal soft tissue sarcoma. METHODS AND METHODS: Retrospective review of consecutive patients with a history of prior IVF therapy referred for MRI evaluation of a gluteal soft tissue mass was performed. Six patients were reviewed, with 5 patients meeting study inclusion criteria. Imaging exams (ultrasound n = 3, MRI n = 5) were assessed for lesion location, morphology, and intrinsic imaging characteristics. One case proceeded to percutaneous biopsy with histopathologic correlation. RESULTS: Average patient age was 43 years (range 38-50). Mean time interval between IVF IM injections and MRI was 5.7 years (range 2.2-13 years). Clinical findings included palpable gluteal mass (5/5) and local pain (4/5). Ultrasound showed heterogeneous subcutaneous lesions with varying complex cystic/solid internal echogenicity. On MRI, each case illustrated an irregularly marginated lesion, mean maximal dimension 3.5 cm (range 1.5-5.9 cm), within the deep gluteal subcutaneous fat composed of solitary (1/5) or multifocal (4/5) lobules demonstrating internal areas of high T1 and homogeneous low T2 fat suppressed signal with surrounding peripheral reticular high T2 signal. Correlative histological assessment showed central areas with features of fat necrosis and a peripheral inflammatory rim. CONCLUSIONS: In the setting of prior IVF therapy, imaging features of an irregularly marginated, deep subcutaneous gluteal lesion with inflammatory soft tissue changes surrounding solitary or multifocal areas of loculated fat signal may be seen as an inflammatory response to previous inadvertent subcutaneous injection(s).

Trunnionosis: the latest culprit in adverse reactions to metal debris following hip arthroplasty.

The imaging findings of periprosthetic soft tissue lesions (pseudotumours) have been typically defined in the context of newer second-generation metal-on-metal hip arthroplasty. More recently, similar findings have been described in the setting of non-metal-on-metal prostheses. Although uncommon, wear and corrosion between the metal surfaces at the head-neck ('trunnionosis') and neck-stem interfaces are the potential culprits. With modular junctions containing at least one cobalt chromium component frequently present in hip arthroplasty prostheses, the incidence of this mode of adverse wear may be higher than previously thought (irrespective of the specific bearing couple used). In the present report, we described a case of a severe adverse local tissue reaction secondary to suspected corrosion at the head-neck taper in a metal-on-polyethylene total hip arthroplasty and reviewed the literature. Knowledge of this topical entity should help radiologists facilitate early diagnosis and ensure early management of this potentially serious complication.

Magnetic resonance imaging features of osseous manifestations of early acquired syphilis.

We report the case of a 64-year-old man who initially presented with a maculopapular rash followed several weeks later by bilateral shin pain and infiltrative cutaneous lesions over the lower legs. The plain radiographs were not contributory, and the patient was referred for a whole-body bone scan, which demonstrated multifocal osseous lesions, including such lesions in the lower legs, skull and facial bones. Magnetic resonance imaging (MRI) demonstrated numerous small tibial and fibular nodular lesions involving the medullary cavity and the cortex. A diagnosis of acquired syphilis was made, based on skin biopsy. Results of serological testing were consistent with recent infection. The patient was treated with intramuscular injection of penicillin, and follow-up MRI demonstrated gradual resolution of the osseous lesions. Bone involvement is a relatively rare manifestation of early acquired syphilis. Although the plain radiographic features of the bony changes in acquired syphilis are well documented, there have been no reports of the magnetic resonance imaging findings in the appendicular skeleton.

Clinical and radiographic response to a local infliximab injection in a patient with chronic sacroiliitis.

BACKGROUND: A 49-year-old man presented to a rheumatology clinic with a 2-month history of low back pain. The pain seemed to be inflammatory in origin, with nocturnal occurrence and substantial early morning stiffness. The patient was previously well, with no history of psoriasis, inflammatory bowel disease or iritis. INVESTIGATIONS: Physical examination, anteroposterior X-ray of the pelvis, isotope bone scan, CT and MRI of the sacroiliac joints, measurement of serum inflammatory markers, HLA-B27 testing, routine and mycobacterial culture of the sacroiliac joint fluid aspirate, tuberculosis skin testing and chest X-ray. DIAGNOSIS: An HLA-B27-negative patient with chronic unilateral sacroiliitis refractory to conventional management. MANAGEMENT: After unsuccessful treatment with various NSAIDs and physical therapy, local corticosteroid injections on two occasions in the affected sacroiliac joint provided transient relief. A subsequent 20 mg injection of infliximab into the affected joint resulted in clinical and radiological improvement that has been sustained for more than 2 years.

Recurrent symptoms after shoulder instability repair: direct MR arthrographic assessment--correlation with second-look surgical evaluation.

PURPOSE: To retrospectively determine the accuracy of direct magnetic resonance (MR) arthrography of the shoulder in patients with recurrent or residual signs and/or symptoms of instability after prior instability repair, with surgical findings as the reference standard. MATERIALS AND METHODS: After institutional ethics review board approval was obtained and informed consent was waived, 40 patients (31 men, eight women; mean age, 28 years) with recurrent instability after previous instability repair who underwent direct shoulder MR arthrography before repeat surgery were studied. Two musculoskeletal radiologists reviewed direct MR arthrographic studies by using consensus agreement in a blinded fashion. MR assessment included evaluation of the labrum (overall, superior, anterior and anteroinferior, posterior and posteroinferior), rotator cuff, biceps tendon, articular cartilage, and presence or absence of a Hill-Sachs lesion. Mean interval between MR arthrography and repeat surgery was 6.2 months (range, 6 days to 36 months). Surgical reports were compared with MR arthrographic results, and accuracy, sensitivity, and specificity of direct MR arthrography were determined. RESULTS: Accuracy, sensitivity, and specificity, respectively, of direct MR arthrography in diagnosis of overall labral tears (n = 26) were 91.9%, 96.2%, and 81.8%; those of superior labral tears (n = 16) were 89.2%, 93.8%, and 85.7%; and those of anteroinferior tears (n = 17) were 91.9%, 100%, and 85%. Overall accuracy for detecting rotator cuff injury (n = 17) was 87.2% (sensitivity, 94.1%; specificity, 81.8%); accuracy for biceps injury (n = 7) was 95.7% (sensitivity, 85.7%; specificity, 100%); accuracy for glenoid and/or humeral articular cartilage abnormality (n = 15) was 76.2% (sensitivity, 73.3%; specificity, 83.3%); and accuracy for Hill-Sachs lesion (n = 14) was 93.3%. CONCLUSION: Direct MR arthrography is accurate (91.9%) for assessing labral pathologic conditions and other internal derangements of the shoulder in patients with recurrent or residual signs and/or symptoms after prior shoulder instability repair.

MR imaging findings of anterior interosseous nerve lesions.

OBJECTIVE: To study and characterise the MR imaging findings of lesions of the anterior interosseous nerve (AIN). MATERIALS AND METHODS: Magnetic resonance imaging (MRI) findings of the forearm of ten patients referred to our institution with suspected AIN lesions were retrospectively studied. Five healthy volunteers with normal forearm MRI findings formed a control group. Two musculoskeletal radiologists assessed the forearm musculature for oedema in the distribution of the AIN, median, posterior interosseous and radial nerves on T2-weighted (T2W) fat-saturated sequences. T1-weighted (T1W) images were assessed and graded for the presence of muscle atrophy and fatty involution. RESULTS: Six patients had undergone surgical exploration; five of these had surgically confirmed AIN compression. Four patients had diagnoses other than AIN compression made on imaging features. Of the cases of proven AIN compression, oedema within the pronator quadratus (PQ) muscle was identified in all cases. PQ atrophy and fatty involution were seen in three (43%) surgically confirmed cases. Cases 2 and 3 also demonstrated oedema in the flexor digitorum profundus (FDP)1 and FDP2 muscles. These cases also showed oedema in the flexor-carpi radialis (FCR) and FDP3/FDP4 muscles, respectively. The four cases of non-AIN compression demonstrated muscle oedema patterns that were atypical for the AIN distribution. They included a rupture of the flexor pollicis longus (FPL) tendon, brachial neuritis, amyotrophic lateral sclerosis and compression of the proximal median nerve. CONCLUSIONS: MRI is a useful investigation in the diagnostic workup of AIN syndrome. AIN syndrome is likely when there is diffuse oedema of AIN innervated muscles on T2W fat-saturated images. The most reliable sign of an AIN lesion is oedema within the PQ. Oedema in the flexor carpi radialis, FDP3 and FDP4, although not in the classical distribution of the AIN, does not preclude the diagnosis of AIN syndrome.

Scoring sacroiliac joints by magnetic resonance imaging. A multiple-reader reliability experiment.

Magnetic resonance imaging (MRI) of the sacroiliac (SI) joints and the spine is increasingly important in the assessment of inflammatory activity and structural damage in clinical trials with patients with ankylosing spondylitis (AS). We investigated inter-reader reliability and sensitivity to change of several scoring systems to assess disease activity and change in disease activity in patients with AS. Twenty sets of consecutive MRI, derived from a randomized clinical trial comparing an active drug with placebo and selected on the basis of the presence of activity at baseline, were presented electronically to 7 experienced readers from different countries (Europe, Canada). Readers scored the MRI by 3 different methods including: a global score (grading activity per SI joint); a more comprehensive global score (grading activity per SI joint per quadrant); and a detailed scoring system [Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system], which scores 6 images, divided into quadrants, with additional scores for "depth" and "intensity." A fourth and a fifth scoring system were constructed afterwards. The fourth method included the SPARCC score minus the additional scores for "depth" and "intensity," and the fifth method included the SPARCC slice with the maximum score. Inter-reader reliability was investigated by calculating intraclass correlation coefficients (ICC) for all readers together and for all possible reader pairs. Sensitivity to change was investigated by calculating standardized response means (SRM) on change scores that were made positive. Overall inter-reader ICC per method were between 0.47 and 0.58 for scoring status, and between 0.40 and 0.53 for scoring change. ICC per possible reader pairs showed much more fluctuation per method, with lowest observed values close to zero (no agreement) and highest observed values over 0.80 (excellent agreement). In general, agreement of status scores was somewhat better than agreement of change scores, and agreement of the comprehensive SPARCC scoring system was somewhat better than agreement of the more condensed systems. Sensitivity to change differed per reader, but in general was somewhat better for the comprehensive SPARCC system. This experiment under "real life," far from optimal conditions demonstrates the feasibility of scoring exercises for method comparison, provides evidence for the reliability and sensitivity to change of scoring systems to be used in assessing activity of SI joints in clinical trials, and sets the conditions for further validation research in this field.

Magnetic resonance imaging of the shoulder in asymptomatic professional baseball pitchers.

The purpose of this study was to evaluate the magnetic resonance imaging findings in both shoulders of asymptomatic professional baseball pitchers. Fourteen pitchers who were without significant prior injury underwent a blinded clinical assessment and magnetic resonance imaging of both shoulders. All images were interpreted by two experienced musculoskeletal radiologists. The appearance of the rotator cuff tendons was graded, with additional evaluation of the biceps, labrum, and osseous structures. Ten athletes were found to have stable shoulders and painless full range of motion. Clinically, four athletes had at least a 40 degrees loss in internal rotation as compared with the nonthrowing arm. There were no significant differences in magnetic resonance imaging findings of the supraspinatus and infraspinatus tendons between the throwing and nonthrowing shoulders. The labrum was abnormal in 79% of the 28 shoulders. Enthesopathic changes of the posterior glenoid labrum were identified in the four pitchers who had loss of internal rotation. We conclude that unenhanced magnetic resonance imaging of the shoulder in asymptomatic high performance throwing athletes reveals abnormalities that may encompass a spectrum of "nonclinical" findings. These data can be useful in separating symptomatic pathologic findings from these variants. Enthesopathic changes of the posterior glenoid labrum in the throwing arm may represent an early Bennett-type lesion. The cause may be excessive traction on the posterior capsule during the pitching motion, with subclinical injury to this area.