The role of magnetic resonance imaging in the diagnostic work-out of myopathies: differential diagnosis between inflammatory myopathies and muscular dystrophies.

OBJECTIVES: The differential diagnosis between idiopathic inflammatory myopathies (IIM) and muscular dystrophies (MD) may be challenging. We analysed the potential role of muscular magnetic resonance imaging (MRI) in the differential diagnosis between IIM and MD. METHODS: MRI of patients (91 IIM and 43 MD), studied with a standardised protocol, have been collected. The presence of oedema, muscular atrophy and intramuscular adipose changes were evaluated. Moreover, we computed a composite score for each MRI item to better discriminate between the two diseases. RESULTS: Oedema was significantly more prevalent in IIM compared with MD in pelvis muscles (p<0.001), anterior lodge and medial lodges (p=0.044) of the thighs. Adipose infiltration/substitution and muscular atrophy were more prevalent in MD, in particular adipose tissue was prevalent in all the compartments of the thighs (p<0.05), atrophy was prevalent at the thighs and pelvis muscles (p<0.001). The probability of IIM increased with higher oedema score and decreased with higher atrophy and intramuscular adipose infiltration/substitution scores. CONCLUSIONS: A different distribution of muscular involvement between IIM and MD has been identified. Muscular MRI may be useful in the differential diagnosis, potentially reducing the number of muscular biopsies that may be reserved only for doubtful cases.

A case of intravascular large B cell lymphoma with brain involvement mimicking progressive multifocal leukoencephalopathy.

Intravascular large B-cell lymphoma (IVLBCL) is a very rare form of extranodal lymphoma, characterized by the proliferation of neoplastic B cells within the lumen of small vessels. Due to its high aggressivity, for years the prognosis had been really poor with only anectodical cases of remission after traditional chemotherapy. More recently, new therapeutic protocols allowed a significant increase in overall survival. It can virtually involve every organ, being skin and central nervous system the most affected. The clinical presentation is often unspecific and insidious; therefore, diagnosis can be challenging. Tissue biopsy, in particular random deep skin biopsy, is the gold standard for definitive diagnosis. We describe the case of a 58-year-old woman with a previous diagnosis of myelofibrosis, who presented with a rapidly progressive neurological deterioration and a brain MRI suggestive of Progressive Multifocal Leukoencephalopathy. Due to the absence of BK and JC viruses in cerebrospinal fluid and the presence of severe myalgias and subcutaneous nodules, a skin and muscle biopsy was performed, allowing diagnosis of IVLBCL. We describe the diagnostic pitfalls of this case, briefly reviewing existing literature about IVLBCL.

The added value of the visual analysis of DWI in post-surgery follow-up of soft tissue sarcoma of the extremities: do we really need ADC?

INTRODUCTION: MRI has a fundamental role in the follow-up of soft tissue sarcomas (STSs). However, the differentiation of recurrences/residual disease from post-surgical changes is a complex task, with a central role for the radiologist. MATERIALS AND METHODS: We retrospectively evaluated 64 post-surgery MRI for extremities STSs. MR protocol included DWI (b = 0, 1000). Two radiologists were asked to consensually evaluate: presence/absence of tumoral nodules, lesion conspicuity, imaging diagnostic confidence, ADC values, and DWI overall image quality. The gold standard was histology or MR follow-up. RESULTS: Thirty-seven lesions in 29/64 patients were confirmed as local recurrence or residual disease (n = 16 ≤ 1 cm) with 1 MR false positive. On DWI, the conspicuity of the proved tumor lesions resulted excellent in 29/37, good in 3/37 and low in 5/37, higher than conventional imaging. A statistically significant higher diagnostic confidence of DWI compared to conventional imaging (p < 0.001) and DCE (p = 0.009) was observed. In the 37 histologically confirmed lesions, mean ADC value was 1.31 × 10-9 m2/s. Overall scar tissues mean ADC was 1.70 × 10-9 m2/s. DWI quality resulted adequate in 81% and unsatisfactory in 5%. CONCLUSIONS: In this highly heterogeneous group of tumors, the role of ADC seems to be limited. Based on our experience, looking at DWI images makes the lesions promptly and easily detectable. This technique gives less deceptive findings making the reader more confident in detecting/excluding tumoral tissue; the main drawback is the image quality and the lack of standardization.

Thigh magnetic resonance imaging for the evaluation of disease activity in patients with idiopathic inflammatory myopathies followed in a single center.

INTRODUCTION: In patients with idiopathic inflammatory myopathies (IIM), magnetic resonance imaging (MRI) has been proposed as a useful tool for diagnosis and follow-up. It may identify muscle inflammation (edema) and fatty infiltration for evaluation of disease activity and damage. Little information is available on the role of MRI in assessment of large cohorts of adult patients with IIM. METHODS: Fifty-one patients underwent MRI of the thigh muscles, laboratory tests, and clinical evaluation, including Physician Global Assessment (PGA) of myositis activity and the Manual Muscle Test 8 (MMT8). RESULTS: Muscle edema correlated significantly with creatine kinase values (P = 0.017) and PGA (P < 0.001). A significant correlation between edema and MMT8 values (P = 0.025) was observed when patients with muscle fatty infiltration were excluded. With respect to clinical diagnosis, the sensitivity of MRI was 92.3%, and specificity was 83.3%. CONCLUSIONS: MRI appears to provide additional information that complements clinical and biochemical examinations. Muscle Nerve 54: 666-672, 2016.

Osteoid osteoma mimicking monoarticular juvenile idiopathic arthritis in a girl.

Osteoid osteoma (OO) is a benign osteogenic neoplasm, usually affecting children and young adults, that is typically characterized by nocturnal pain and response to non-steroidal anti-inflammatory drugs. OO is frequently misdiagnosed because it mimics juvenile idiopathic arthritis (JIA), bone infection or malignancy. Herein we report the case of a girl who presented with chronic monoarthritis of the knee mimicking JIA. After 1 year, OO of the femoral distal metaphysis was diagnosed. OO was treated with computed tomography-guided radiofrequency ablation with disappearance of the symptoms and resolution of the neoplasm. No recurrences have been observed 3 years after the treatment. This case highlights that intra-articular or juxta-articular OO should be suspected in the case of misleading symptoms and signs, such as swelling, lack of typical pain and synovial thickening on ultrasound; needle biopsy of the lesion is necessary in the case of confusing imaging.

Automatic 2D registration of renal perfusion image sequences by mutual information and adaptive prediction.

UNLABELLED: The objective of this study was to develop an automatic image registration technique capable of compensating for kidney motion in renal perfusion MRI, to assess the effect of renal artery stenosis on the kidney parenchyma. MATERIALS AND METHODS: Images from 20 patients scheduled for a renal perfusion study were acquired using a 1.5 T scanner. A free-breathing 3D-FSPGR sequence was used to acquire coronal views encompassing both kidneys following the infusion of Gd-BOPTA. A two-step registration algorithm was developed, including a preliminary registration minimising the quadratic difference and a fine registration maximising the mutual information (MI) between consecutive image frames. The starting point for the MI-based registration procedure was provided by an adaptive predictor that was able to predict kidney motion using a respiratory movement model. The algorithm was validated against manual registration performed by an expert user. RESULTS: The mean distance between the automatically and manually defined contours was 2.95 ± 0.81 mm, which was not significantly different from the interobserver variability of the manual registration procedure (2.86 ± 0.80 mm, P = 0.80). The perfusion indices evaluated on the manually and automatically extracted perfusion curves were not significantly different. CONCLUSIONS: The developed method is able to automatically compensate for kidney motion in perfusion studies, which prevents the need for time-consuming manual image registration.

Role of dynamic MRI in the follow-up of acute Charcot foot in patients with diabetes mellitus.

PURPOSE: To evaluate the usefulness of magnetic resonance imaging (MRI) in assessing the level of activity of acute Charcot foot, monitoring treatment response and predicting healing time. MATERIALS AND METHODS: Forty diabetic patients with acute Charcot foot were prospectively enrolled. Patients underwent limb immobilization and were followed every 3 months by clinical examination (skin temperature and circumferences) and MRI. MR protocol included T1-weighted and fast spin echo inversion recovery (FSE-IR) sequences, and a dynamic study (fast spoiled gradient echo), after gadolinium administration (0.1 ml/kg). The contrast medium uptake rate at D-MRI and the signal intensity (SI) ratio on the FSE-IR sequence were measured. RESULTS: At baseline, mean contrast medium uptake rate was 136 ± 49.7% and the mean SI ratio was 5 ± 3. A high intra- and inter-observer agreement was found for the contrast medium uptake rate, whereas a low agreement was observed for the SI ratio. At 3 months' follow-up, reduction of the contrast medium uptake rate was observed in all patients with improved clinical findings (n = 34), whereas the SI ratio was reduced in 15/34 (44.1%) patients. Mean healing time was significantly related to the baseline contrast medium uptake rate (P=0.005); it was 5.3 ± 2.7 months in patients with contrast medium uptake rate ≤ 100%, compared with 9.1 ± 2.5 months in the remaining patients (P=0.0003). CONCLUSIONS: Contrast medium uptake rate obtained at D-MRI represents a reproducible parameter that is reliable for predicting and monitoring treatment outcome in acute Charcot foot.

Humeral greater tuberosity osteolysis as a complication of intraosseous calcification migration: natural history depicted by imaging.

Migration of calcification within the bone leading to greater tuberosity osteolysis is a peculiar complication of the calcifying tendinitis of the rotator cuff. The case of a 38-year-old woman complaining of right shoulder pain, which had been going on for one year, is hereby described. The evolution of the infraspinatus tendon calcifying tendinitis leading to osteolysis of the greater tuberosity of the humerus is depicted by imaging and, particularly, by the MR and CT features changing over time. In this paper we focus on the importance of both MR and CT exams in the diagnostic process of the different phases of the disease. The correlation between clinical symptoms and imaging features is also helpful for imaging interpretation: the most painful phase corresponds to the migration of the calcification, whereas pain tends to decrease when the osteolysis develops. Awareness of the existence of this condition may prevent unnecessary invasive procedures.

Bioactive Glass in a Rare Case of Osteomyelitis of the Heel in a Guillain-Barré Syndrome: A Case Report.

Guillain-Barré syndrome (GBS) represents an acute inflammatory immune-mediated demyelinating polyradiculoneuropathy with an incidence of 0.6 per 100 000 people. In this article, we report the case of a 19-year-old girl affected by GBS since the age of 2 who presented at our clinic complaining for a chronic plantar hindfoot-infected ulceration. Serology showed increase of inflammatory markers and leukocytosis, and magnetic resonance imaging revealed osteomyelitis of calcaneum and soft tissue alterations with air bubbles. The patient was treated in our clinic by an integrated multidisciplinary approach consisting of immediate admission, soft tissue and bone debridement, and administration of antibiotics under the close control of infectious disease specialist. After the control of acute condition, the patient underwent negative pressure therapy associated with instillation of antiseptic solution until the restoration of bone and soft tissue loss of substance and, eventually, to the application of bioactive glass substitute until the achievement of complete wound healing.

Acral Dedifferentiated Chondrosarcoma: Report of a Case Arising in the Proximal Phalanx of the Fourth Finger.

Dedifferentiated chondrosarcoma is a well-recognized entity, but its occurrence in the distal extremities is exceedingly rare. We present the case of a 49-year-old woman who experienced local recurrence of an "enchondroma" of the proximal phalanx of the fourth finger of the left hand, which had been initially treated with intralesional curettage at another hospital 4 years before, and 1 year before for a local recurrence. The imaging findings indicated an aggressive behavior, and an incisional biopsy showed a highly cellular proliferation of spindle and pleomorphic elements without evidence of matrix production intermixed with few fragments of a well-differentiated cartilaginous neoplasm with bland cellular atypia, focal nuclear hyperchromatism, and binucleation. An isocitrate dehydrogenase 2 R172S mutation was detected. The final diagnosis was dedifferentiated chondrosarcoma. Despite amputation of the fourth finger, the patient developed lung metastases and further local relapse. Recurrent cartilaginous tumors of the extremities should not be underestimated and should be followed in view of the possible acquisition of aggressive clinical behavior.

Musculoskeletal MRI at 7 T: do we need more or is it more than enough?

Ultra-high field magnetic resonance imaging (UHF-MRI) provides important diagnostic improvements in musculoskeletal imaging. The higher signal-to-noise ratio leads to higher spatial and temporal resolution which results in improved anatomic detail and higher diagnostic confidence. Several methods, such as T2, T2*, T1rho mapping, delayed gadolinium-enhanced, diffusion, chemical exchange saturation transfer, and magnetisation transfer techniques, permit a better tissue characterisation. Furthermore, UHF-MRI enables in vivo measurements by low-γ nuclei (23Na, 31P, 13C, and 39K) and the evaluation of different tissue metabolic pathways. European Union and Food and Drug Administration approvals for clinical imaging at UHF have been the first step towards a more routinely use of this technology, but some drawbacks are still present limiting its widespread clinical application. This review aims to provide a clinically oriented overview about the application of UHF-MRI in the different anatomical districts and tissues of musculoskeletal system and its pros and cons. Further studies are needed to consolidate the added value of the use of UHF-MRI in the routine clinical practice and promising efforts in technology development are already in progress.

MRI anatomical preoperative evaluation of distally based peroneus brevis muscle flap in reconstructive surgery of the lower limb.

BACKGROUND: The distally based peroneus brevis muscle flap has proved to be a simple solution for small- to moderate-sized wounds of the lower limb. The length of the muscle belly suitable for coverage is a crucial parameter. In this study, we evaluated the capability of 3D MRI of the lower limb to measure it preoperatively. METHODS: Between 2008 and 2017, 32 patients with lower limb defects underwent preoperative MRI to measure the peroneus brevis muscle length. All patients underwent reconstruction, and the muscle was measured again intraoperatively during surgical dissection. Surgical measurements were then compared to the MRI ones. RESULTS: MRI measures of the peroneus brevis muscle belly ranged from 9 to 21 cm (µ = 14.44 ± 3.43 cm), and intraoperative measures ranged from 9 to 20 cm (µ = 14.2 ± 2.3 cm). Thirty of 32 intraoperative measures corresponded to the MRI ones (variation = ± 1 cm, r = 0.92, p = 0.002). One patient showed an intraoperative muscle length 3 cm shorter than the MRI measure, and another patient had intraoperative muscle length 3 cm longer than the MRI one. All flaps survived, and no secondary local flap coverage was required, with no flap-related complication, limited donor site morbidity, and acceptable patient discomfort. CONCLUSIONS: The reverse peroneus brevis muscle flap is a versatile alternative to free flap reconstruction in small- to moderate-sized defects of the lower limb. Preoperative 3D MRI is accurate to evaluate the anatomy of the muscle when performed by an expert radiologist. In our experience, it should become part of preoperative workup before performing a peroneus brevis flap procedure.

A Metastatic Squamous Cell Carcinoma in a Diabetic Foot: Case Report.

A 72-year-old male was referred to our hospital for a plantar ulceration that had occurred many years earlier. The lesion, with exuberant granulation and large areas of necrosis and fibrin, had long been treated by plastic surgeons with no positive evolution. At admission in our hospital no ischemia was detected, and foot radiograph was negative for bone involvement. The patient underwent a foot magnetic resonance imaging, which showed high vascularization in the plantar region and early capture of the contrast medium. We then performed multiple biopsies of the ulceration that revealed a moderately differentiated squamous cell carcinoma. The total body computed tomography exam raised a systemic involvement. A lymph node biopsy and immunohistochemistry assay on the pleural cytological sample proved the presence of a primary squamous cell carcinoma of the foot with systemic dissemination. Although rare, squamous cell carcinoma could be associated with chronic nonhealing ulcers; therefore, when a lesion does not heal, despite adequate standard treatment, its etiopathogenesis should be challenged.

Semiquantitative analysis of the histopathological features of the neuropathic foot ulcer: effects of pressure relief.

OBJECTIVE: This study was designed to evaluate the histopathology of neuropathic ulcers and whether pressure relief could change such histological patterns. RESEARCH DESIGN AND METHODS: We compared neuropathic plantar ulcers tissue excised from 10 diabetic patients (group A) with those taken from 10 patients with comparable lesions and glycemic control after 20 days in a total contact cast (group B). Tissue specimens were blindly examined by two independent pathologists for hyperkeratosis, fibrosis, cutaneous annexes, capillaries, inflammation, cellular debris, and granulating tissue. For each parameter, quantification was obtained according to an arbitrary score: 0, absent; 1, present in <33%; 2, present in 34-66%; and 3, present in >67% of the lesion. RESULTS: Patients in group B showed a marked reduction in ulcer size after 20 days of casting (P < 0.01). The histopathological features of the two groups markedly differed. Group A patients showed a predominance of inflammatory elements as well as matrix alterations, vessel disruptions, inflammation, and debris. Group B ulcers showed a shift toward a reparative pattern with prevalence of neoformed capillaries and fibroblasts. Semiquantitative analysis confirmed the prevalence of hyperkeratosis, fibrosis, inflammation, and cellular debris in group A patients (P < 0.05), whereas cutaneous annexes, capillaries, and granulating tissue were more prevalent in group B lesions (P < 0.01). CONCLUSIONS: These results indicate that pressure relief with a total contact cast is associated with changes in the histology of neuropathic foot ulcers, indicating reduction of inflammatory and reactive components and acceleration of reparative processes.

Muscle exercise in limb girdle muscular dystrophies: pitfall and advantages.

Different genetic mutations underlying distinct pathogenic mechanisms have been identified as cause of muscle fibers degeneration and strength loss in limb girdle muscular dystrophies (LGMD). As a consequence, exercise tolerance is affected in patients with LGMD, either as a direct consequence of the loss of muscle fibers or secondary to the sedentary lifestyle due to the motor impairment. It has been debated for many years whether or not muscle exercise is beneficial or harmful for patients with myopathic disorders. In fact, muscular exercise would be considered in helping to hinder the loss of muscle tissue and strength. On the other hand, muscle structural defects in LGMD can result in instability of the sarcolemma, making it more likely to induce muscle damage as a consequence of intense muscle contraction, such as that performed during eccentric training. Several reports have suggested that supervised aerobic exercise training is safe and may be considered effective in improving oxidative capacity and muscle function in patients with LGMD, such as LGMD2I, LGMD2L, LGMD2A. More or less comfortable investigation methods applied to assess muscle function and structure can be useful to detect the beneficial effects of supervised training in LGMD. However, it is important to note that the available trials assessing muscle exercise in patients with LGMD have often involved a small number of patients, with a wide clinical heterogeneity and a different experimental design. Based on these considerations, resistance training can be considered part of the rehabilitation program for patients with a limb-girdle type of muscular dystrophy, but it should be strictly supervised to assess its effects and prevent possible development of muscle damage.

Predictive value of clinical findings for temporomandibular joint effusion.

OBJECTIVE: The aim of this work was to evaluate the predictive value of clinical symptoms for magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) effusion. STUDY DESIGN: Sixty-one patients with TMJ pain were assessed by means of a standardized clinical examination and MRI. A calibrated investigator evaluated the presence of 8 clinical indicators (predictors) of TMJ effusion (outcome variable). A logistic regression analysis was performed to detect significant associations between clinical symptoms and MRI findings of TMJ effusion. The accuracy of the final logit to predict effusion was compared with that derived from univariate analysis. RESULTS: A clinical examination based upon the assessment of pain in the TMJ with lateral palpation, with posterior palpation, during motion, and during maximum assisted opening, and the presence of click and crepitus sounds has an accuracy of 78.7% to predict TMJ effusion. Among the single clinical symptoms, the most reliable predictor of TMJ effusion is the presence of pain with lateral palpation (accuracy 76.2%; K =.525). CONCLUSION: The use of a multiple regression approach demonstrated that an extensive clinical assessment which considers 6 main indicators consents to predict accurately the presence of MRI TMJ effusion. Based on these findings, MRI assessment should be reserved for patients in which the exact disc-condyle relationship needs to be evaluated.

Could the sling position influence the clinical outcome in male patients treated for urinary incontinence? A magnetic resonance imaging study with a 3 tesla system.

OBJECTIVE: To analyze the morphologic changes visible on magnetic resonance imaging (MRI) after sling procedure in continent patients and to compare MRI findings with the incontinent ones, to detect possible factors explaining the different clinical outcomes. METHODS: Twenty-seven male patients who were treated with Advance sling for urinary stress incontinence after prostate surgery were enrolled: 16 had clinical recovery, whereas 11 had persistent incontinence. Patients after sling were defined as continent if used 0-1 dry "security pad" or incontinent >1 pad. Magnetic Resonance examinations were performed with a 3 Tesla system and included 3-dimensional T2-weighted sequence. Three readers performed a qualitative (representation of the bulb and indentation of the sling) and a quantitative analysis (length of the bulb posterior to the sling and distance of the sling from a line bisecting the pubic symphysis). RESULTS: The sling was clearly recognizable in all 16 continent patients but only in 2 of 11 incontinent ones. The length of the bulb posterior to the sling was >10 mm (range, 10-28) in all continent patients and in 2 of the incontinent ones. The sling was coincident with a line drawn through the long axis of the pubic bone in 9 of 16 continent patients. A statistically significant association was found between MRI qualitative findings and continence status (P <.0001). CONCLUSION: On the basis of our MRI results, the position of the sling and, in particular, the length of the urethral bulb posterior to the sling seem to be correlated with continence and must be considered in case of treatment failure.