Study in Agaricus subgenus Minores and allied clades reveals a new American subgenus and contrasting phylogenetic patterns in Europe and Greater Mekong Subregion.

Within Agaricus subg. Minores, A. sect. Minores remains a little-studied section due generally to its delicate sporocarps often lacking taxonomically relevant morphological characters. To reconstruct the section, using the recent taxonomic system based on divergence times, and to evaluate the species diversity of A. sect. Minores in the Greater Mekong Subregion, 165 specimens were incorporated in phylogenetic analyses. A dated tree based on nuclear ITS, LSU and tef1-α sequence data allowed us to better circumscribe A. subg. Minores and to propose a new subgenus, A. subg. Minoriopsis, which is only known from tropical and subtropical regions of the Americas. A larger tree based on ITS sequences indicated that, with 81 phylogenetic species, the reconstructed section Minores is now one of the largest sections in the genus. Within A. subg. Minores, a new section, A. sect. Leucocarpi, and eleven new species are described from the Greater Mekong Subregion. Thirty-eight species of A. sect. Minores from this region of Asia were distributed in multiple clades that successively diverged over the past 24 million years. In contrast, species reported from Europe mostly grouped in a single non-tropical clade, suggesting a major species diversification following the middle Miocene climatic optimum.

Magnetic resonance arthrography of the wrist with axial traction: An iconographic review.

Stress maneuvers inspired by arthroscopic techniques have been previously studied for MRA of shoulder, hip, knee and wrist. Axial traction in MRA of the wrist is advantageous to study intrinsic ligaments and cartilage, but seems useless to assess tendons or nerves disorders. Based on our experience and a well-chosen iconography, we would like to emphasize the contribution of axial traction in MRA of wrist disorders.

Pseudo-cysts, lipomas, infarcts and simple cysts of the calcaneus: are there different or related lesions?

Pseudocysts, lipomas, infarcts and simple cysts of the calcaneus are described as different entities in the medical literature. However, some evolutions or associations may suggest a relationship which is not yet demonstrated in all cases. The aim of this article is to describe each lesion and emphasize their different characteristics that may suggest a relationship between them.

[Evaluation of the risk of overheating and displacement of orthodontic devices in magnetic resonance imaging]. / Evaluation des risques d'échauffement et de déplacement des appareils orthodontiques en imagerie par résonance magnétique.

The use of magnetic resonance imaging (MRI) in the exploration of the orofacial region of patients who have orthodontic appliances can be disturbed by artifacts, with a theoretical risk of displacement and overheating of the different materials used in odontology. The purpose of this study was to evaluate the thermal effects and the risk of displacement induced by MRI on certain metallic devices used in orthodontics. The results show a very moderate increase in temperature of the materials during MRI exposure, less than 1 degrees C, in particular in the metal wire linking the brackets. The maximal forces observed were on the order of 0.27 N. The risk of detachment and displacement seems to be nonexistent at 1.5 Tesla when the usual recommendations are respected. Temporary removal of the wire and verification of the adhesive is recommended. However, priority should be given to nonmagnetic or slightly magnetic material to limit artifacts as much as possible when exploring the head region.

[Interventional sonography]. / L'échographie interventionnelle.

Diagnostic and therapeutic interventional procedures are rapidly expanding and, when guided by imaging, are more efficient then when performed with a blinded technique. Compared to fluoroscopy and CT, ultrasound does not utilize ionizing radiation. It can facilitate needle placement for arthrography, tenography or bursography or it can guide a variety of procedures such as aspiration, arthrocentesis, local steroid injections and needling of tendon calcifications. Technological improvements have increased the precision of ultrasound guidance and have contributed to reduce the risk of complication. Real time scanning allows simultaneous visualization of the target and of needle progression and has diminished the rate of complications, that are infrequent if the operator uses a strict sterile technique and respects the contraindications.

[Is the rings and arcs pattern of mineralization specific for chondroid matrix tumors?]. / Les calcifications annulaires sont-elles spécifiques des matrices tumorales cartilagineuses?

The rings and arcs pattern of mineralization is considered pathognomonic for cartilaginous tumors. The authors report four cases of osteoblastomas in which the presence of such a pattern of mineralization mistakenly lead to a diagnosis of cartilaginous tumor. These densities are not explained by the histologic findings.

[Monostotic fibrous dysplasia of the calcaneus: two case reports]. / Dysplasie fibreuse monostotique du calcaneus: à propos de 2 cas.

The authors report two unusual cases of aggressive monostotic fibrous dysplasia involving the calcaneus. This lesion occurs on the 2th decade of life. The main symptom is talalgia. On plain films, differential diagnosis includes aggressive cystic or pseudocystic lesions of the calcaneus. On MR imaging, the tumor matrix is more suggestive of the diagnosis. Treatment of this aggressive form of fibrous dysplasia consists of a surgical curettage completed by cryotherapy and graft because of a high level of recurrence.

[Imaging of chilhood and adolescent scoliosis]. / Imagerie des scolioses de l'enfant et de l'adolescent.

Scoliosis is frequent, especially during the peripubertal period, which corresponds to the period of greatest activity. About 75% of scoliosis are idiopathic, while the remaining 25% can be divided into neuromuscular, congenital and miscellaneous etiologies. When it is associated with pain, a comprehensive work up should be undertaken to identify the underlying etiology of the scoliosis. Idiopathic scoliosis is typically evaluated using standard radiographs. The number of follow-up radiographs and radiation exposure must be maintained to a minimum. Radiation safety guidelines and protocols must be implemented. Large cassettes can be replaced by digital acquisitions using units with reconstruction software. The technique of evaluation of these scoliosis series radiographs as well as their results will be reviewed. Recent data regarding the evaluation of spinal and pelvic balance parameters in the standing position will be introduced. Atypical idiopathic and other scoliosis require additional evaluation. Computed tomography, with 2D and 3D reformations, is ideal for evaluation of bony anomalies. MRI is ideal for evaluation of the spinal canal and cord, from the skull base down to the sacrum, for all patients with surgical scoliosis or patients with neurological symptoms. The increased availability of MR imaging has resulted in an increased number of so-called idiopathic asymptomatic scoliosis where an underlying anomaly can be identified.

Giant cystic Schmorl's nodes: imaging findings in six patients.

OBJECTIVE: We describe the imaging findings of an unusual type of Schmorl's node appearing as giant cystlike lesion of the vertebral bodies. CONCLUSION: Giant cystic Schmorl's nodes are unusual entities; their radiologic appearance differs dramatically from the classic description and is diagnostically challenging. However, the appearance of these nodes on conventional radiographs and especially on MR images is characteristic. Knowledge of this entity would help to eliminate unnecessary invasive diagnostic or therapeutic procedures.

Anterolateral compartment of the ankle in the lateral impingement syndrome: appearance on CT arthrography.

OBJECTIVE: This article describes the appearance of the anterolateral recess of the posttraumatic ankle on CT arthrography and clearly shows the benefit of this technique in the diagnosis of soft-tissue impingement. MATERIALS AND METHODS: The study was carried out on 44 patients examined by CT arthrography and arthroscopy for chronic, posttraumatic ankle pain. The analysis principally concerned the lateral compartment--in particular, the synovial regularity and the cartilage of the talar dome. RESULTS: Four CT patterns were identified: type 0, uniform filling of the recess with clear limits; type I, intraarticular linear structure outlined by contrast agent; type II, nodular formation in the lateral groove; and type III, irregular appearance of the edges of the lateral groove. Ninety-one percent (10/11) of type II patterns were characterized as meniscoid lesions by arthroscopic examination, 100% (14/14) of type III patterns corresponded to an abundant fibrous reaction, and arthroscopic findings were normal for 100% (2/2) of type 0 patterns and 88% (15/17) of type I patterns. The latter was thus considered as a normal variant outlining the accessory anterior inferior tibiofibular ligament. Type II and III lesions were statistically associated (p = .001) with a chondropathy when time from initial trauma was greater than 22 months. CONCLUSION: CT arthrography provides evidence of anterolateral soft-tissue impingement--in particular, in type II or III patterns. These lesions are statistically associated with a chondropathy.

[Para-articular and intraosseous synovial cysts and articular mucoid cysts]. / Kystes synoviaux et kystes mucoïdes articulaires, para-articulaires et intra-osseux.

The authors review the mechanism and imaging findings of intraarticular, juxtaarticular, and intraosseous ganglion cysts. They specially emphasize particular features according to the most frequent locations.

[Imaging of Erdheim-Chester disease]. / Imagerie de la maladie d'Erdheim-Chester.

Erdheim-Chester disease is a form of Histiocytosis which involves the adults and is distinct from Histiocytosis X. It is characterized by a constant diaphyseal and metaphyseal bone involvement predominating in the lower links. The diagnosis can readily be envisaged when the typical radiological findings are present. Bone involvement may be isolated and well tolerated, or can be associated with systemic involvement and a severe prognosis. We describe three cases of women aged 46, 50 and 73 years. One patient presented with isolated bone lesions, while the two others had a multiorgan localization. From the three cases and from an extensive review of the literature, we describe the spectrum of bone and visceral lesions that can be seen by imaging. The emphasis is put on lesions of the skeletal system, the retroperitoneum, the nervous system, and the pericardium. Furthermore, the relationships between Erdheim-Chester disease and Histiocytosis X are discussed.

Distal rupture of the tendon of biceps brachii. Evaluation by MRI and the results of repair.

We report ten cases of rupture of the distal part of the tendon of biceps brachii in patients aged from 27 to 58 years. MRI allowed assessment of the degree of retraction of the tendon which was related to the integrity of the bicipital expansion. When the retraction exceeded 8 cm the expansion was always ruptured. When there was doubt, or in longstanding injury, MRI allowed the lesions to be defined. Surgical repair was by reinsertion on the radial tuberosity at one or two fixation points in eight patients and reinsertion on the anterior brachial muscle in one. The other patient refused surgery. The MRI findings were confirmed at operation. Use of fixation points allowed minimal intervention, thereby reducing the risk of damaging the radial nerve. One year after operation, dynamometric evaluation of the strength of flexion and supination confirmed that the best results were obtained by reinsertion to the radial tuberosity.

[Acromio-clavicular joint cyst. Surgical treatment]. / Kyste de l'articulation acromio-claviculaire. Traitement chirurgical.

A chronic cyst of the acromioclavicular joint was treated in 3 patients who were followed up for an average period of 26 months. All three were over 60 years old and presented with a massive rupture of the rotator cuff with a subnormal range of passive motion; active motion was variably affected and was painful. The patients underwent resection of one cm of the lateral end of the clavicle, together with resection of the cyst and synovectomy of the upper part of the pathologic humero-acromial joint; the coraco-acromial ligament was left in place. With a mean follow-up of 26 months, the 3 patients have significant pain relief and no cyst has recurred. The authors propose a mechanism to explain the persistence of the cysts in patients with massive rotator cuff tear: elevation of the arm brings the humeral head upwards and forces synovial fluid into the acromioclavicular joint through a perforation in the frayed capsule; this communication is later obstructed by synovial fringes which prevent drainage of the fluid. Excision of the synovium cures the problem.

Traumatic tear of the rotator interval.

We studied 10 patients with capsular tear of the glenohumeral joint in the rotator interval -- the triangular space separating the supraspinatus and subscapular tendons. The patients, manual laborers and athletic people, had no previous shoulder pain. Tears appeared after forced internal rotation caused by trauma. The pain was anterior and radiated distally. Pain was absent at rest but recurred immediately after activity was resumed. On examination, range of motion was normal. Hawkins' impingement sign and the palm-up test usually caused pain. Radiographic findings were normal. Arthrography showed leakage of contrast medium into the subscapularis fossa. The tear was not visualized with ultrasonography or magnetic resonance imaging. Eight patients underwent an operation consisting of minimal acromioplasty with coracoacromial ligament resection, coracoidplasty, and suture of the rotator interval. All patients had relief of pain and return of full function.

[Deep muscular lipoma of the shoulder. Apropos of 4 cases]. / Lipomes musculaires profonds de l'épaule. A propos de 4 cas.

PURPOSE OF THE STUDY: The authors report 4 cases of inter and intra-muscular lipoma of the shoulder and make a review of the diagnosis of this localization. MATERIAL AND METHODS: All 4 cases had shoulder pain and some limitation of shoulder motion, one had hypoesthesia on the lateral side of the arm. 3 had magnetic resonance imaging (MRI) and two ultrasonography examination, three of them had a surgical resection and for one surgery was considered too aggressive and had a MRI control one year later. RESULTS: There was no problem for the surgical procedure and the histology confirmed the diagnosis. The last patient had a rehabilitation program and the MRI control showed lesion stability. DISCUSSION: Lipoma are rare, X-rays, ultra-sonography and CT scans are not sufficient, MRI is the best exploration to differentiate lipoma and lipo-sarcoma, but the main problem is for low grade sarcoma. Histology is the only way to make the diagnosis with the whole tumor.

[Epicondylitis induced by fluoroquinolones in athletes. Apropos of 2 cases]. / Epicondylites induites par les fluoroquinolones chez le sportif. A propos de 2 cas.

Epicondylitis occurred in two leisure athletes who were taking fluoroquinolones. No similar cases have been reported in the literature. In both cases, pain occurred early after initiating drug therapy. Pain was intense and was not controlled by usual care. Echography demonstrated major inflammatory lesions with pseudo-necrosis. Magnetic resonance imaging confirmed the lesions and gave evidence of infraclinical lesions of the adjacent tendons. Surgical disinsertion of the epicondyles with biopsy was indicated due to the persistent pain. Histological examination revealed unspecific lesions of hyalin degeneration and a few giant cells in one case. Pain disappeared after surgery and the patients were able to return to their work, but neither was able to continue his sports activity. Lesions of the Achilles tendon have been observed in patients taking fluoroquinolone and the two cases reported here confirm the possibility of other localizations. Care must therefore be taken when prescribing these antibiotics in patients at risk (dialysis patients, those on corticosteroids, high-performance athletes).

Isolated avulsion fracture of the lesser tubercle of the humerus in children.

Isolated avulsion fracture of the lesser tuberosity of the humerus has been reported in few instances. We present a case in a 15-year-old boy who was injured 2 years earlier. Clinical, radiological and interoperative findings are presented and discussed.