Do dermatomyositis and polymyositis affect similar thigh muscles? A comparative MRI-based study.

OBJECTIVES: Dermatomyositis (DM) and polymyositis (PM) commonly cause weakness of the thigh muscles. However, it is debated whether DM and PM affect similar thigh muscles. Muscle oedema on fat-suppressed MRI sequences is thought to represent active inflammation. In this study, we aimed to assess which thigh muscle groups are preferentially inflamed in DM and PM, respectively, using short-tau inversion-recovery MRI sequences. METHODS: We analysed 71 patients from 2 Rheumatology centres, 31 with DM and 40 with PM diagnosed according to the Bohan and Peter criteria. MRI oedema (1=present, 0=absent) was assessed bilaterally on fat-suppressed sequences in 17 pelvic floor and thigh muscles. An MRI oedema score (range 0-17) was calculated by adding the separate scores bilaterally and dividing them by two. Inter-rater variability was assessed by intraclass correlation coefficient. Fisher's exact test was used to compare binomial data. RESULTS: Age and gender ratio were similar in patients with DM and PM. Disease duration (months, mean±SD) was shorter (20±31) in DM than in PM (53±69) (p=0.02). The intraclass correlation coefficient between the radiologists involved was 0.78. Muscle oedema was more common in DM than in PM except in the posterior thigh muscles. In particular, 68% of patients with DM had involvement of at least one anterior thigh muscle versus 38% of patients with PM (p=0.02). CONCLUSIONS: Compared with PM, DM affects more thigh muscles, except those of the posterior compartment, which are equally involved in both disorders. These findings may be useful to target physiotherapy at the more frequently affected muscles.

18F-Fluorodeoxyglucose positron emission tomography for the assessment of myositis: a case series.

OBJECTIVES: To establish whether 18FFluorodeoxyglucose (FDG) positron emission computerised tomography (FDG-PET/CT) might reveal active disease in patients with myositis. METHODS: We studied 12 patients with active myositis (2 polymyositis, 10 dermatomyositis). The controls consisted of 14 randomly chosen subjects without muscle disease. FDG uptake was expressed as the ratio of maximum proximal muscle to liver standardised uptake value. Magnetic resonance of the thigh and pelvic floor muscles was performed on a 1.0 or 1.5T scanner using a surface coil. Oedema (1= present, 0=absent) was assessed by fat suppressed sequences in 17 muscles and a score (0-17) calculated by adding the separate scores. Muscle strength was evaluated in 12 muscle groups by manual muscle test and graded according to the extended Medical Research Council scale (0-5). RESULTS: FDG uptake in proximal muscles was significantly higher in patients with myositis (median 0.58, interquartile range 0.52) than in those without (median 0.30, interquartile range 0.09; p<0.001 Mann-Whitney U-test). FDG muscle uptake in patients with myositis did not correlate with disease duration, creatine kinase levels, muscle strength, or magnetic resonance scores. CONCLUSIONS: FDG-PET/CT can reveal FDG uptake by affected muscles of patients with myositis and might potentially be useful to assess myositis activity.

Administration of conscious sedation by a neuroradiology team during percutaneous vertebroplasty and spinal biopsy procedures.

INTRODUCTION: Percutaneous vertebroplasty, i.e. the consolidation of a vertebral body with polymethylmethacrylate, is a safe and effective image-guided technique increasingly used as a treatment option for different pathologic conditions, mainly vertebral body fractures secondary to osteoporosis, hemangiomas and metastasis. The procedure, although minimally invasive, could be painful and is better tolerated if a conscious sedation regimen is added to local anesthesia. An anesthesiologist usually performs the sedo/analgesia, but frequently, he is not available in our angiography unit, so we have begun to perform the sedo/analgesia ourselves following an analogous situation that physicians of the Digestive Endoscopic Unit of our institution experienced some years ago. METHODS: Using the guidelines developed by Italian Society of Digestive Endoscopy, Italian Society of Anesthesia, Analgesia, Reanimation and Intensive Therapy and National Association of Endoscopy Operators and Technicians as a starting point, we then adapted their protocol to our vertebroplasty requirements, after an adequate training period carried out by our anesthesiologist staff. RESULTS: The results have been very satisfactory, greatly appreciated by patients for good pain control; we have never registered any adverse effects nor have we had any particular problems in controlling sedation or monitoring procedures. CONCLUSION: In our experience, we have observed that conscious sedation can be safely administered by neuroradiologists during spinal procedures, provided that some basic rules are respected regarding patient selection and monitoring, personnel training and angiography equipment.

MRI patterns of invasive lobular breast cancer.

Dr. Schelfout and colleagues, in the March 2004 issue of European Radiology described six tumor morphologic patterns of invasive lobular breast cancer. We retrospectively compared findings on preoperative MR imaging in 18 patients with invasive lobular cancer performed at our institution and we found an additional morphologic pattern in our population: a mass with regular margins (five cases).

Desmoplastic fibroma of the distal tibia: A case report of a minimally invasive histological diagnosis.

Desmoplastic fibroma (DF) is a benign, rare fibroblastic intraosseous neoplasm histologically resembling a desmoid soft tissue tumor. Although classified as benign, DF frequently exhibits an aggressive behavior, has a moderate-to-high recurrence rate, and often causes pathological fractures and extensive bone destruction. This case report presents an incidentally detected DF of the tibia, which was diagnosed using a minimally invasive approach. A 36-year-old African female patient was referred to the Department of Diagnostic Imaging of Arcispedale Santa Maria Nuova-IRCCS (Reggio Emilia, Italy), to be examined by a computed tomography scan on an outpatient basis, after an x-ray examination of the tibia, which was performed after an injury to exclude the presence of a fracture, revealed a hyperlucency of unknown origin. The aim of this study was to discuss the clinical, histological, immunohistochemical and radiographic characteristics of this rare neoplasm, with a focus on image-guided bone biopsy.