The accuracy of MRI for the diagnosis of ramp lesions.

OBJECTIVES: To assess the diagnostic accuracy of MRI in diagnosing ramp lesions in patients with an acute lesion of the anterior cruciate ligament (ACL). MATERIALS AND METHODS: All consecutive patients over 15 years of age who underwent surgical repair of the ACL at a single hospital between January and May 2019, with MRI data available, were included in this retrospective study, except patients who had previous knee surgery. The gold standard was arthroscopic evaluation. Two trained radiologists with 5 and 14 years of experience did a blinded review of the MRIs. The following pathological signs were studied: complete fluid filling between the capsule and the posterior horn of the medial meniscus, irregular appearance of the posterior wall of the medial meniscus, oedema of the capsule, fluid hyperintensity in contact with the medial meniscus and anterior subluxation of the medial meniscus. Logistic regressions in univariate then multivariate analysis were carried out and measures of diagnostic accuracy and interobserver agreement were calculated with R software (version 3.6). RESULTS: Fifty-seven patients were included. Twelve had a ramp lesion diagnosed by arthroscopy (21%). Only complete fluid hyperintensity between the posterior horn of the medial meniscus and the capsule was significantly associated with ramp lesions (P value < 0.01). The diagnostic accuracy of this specific sign was moderate, with a specificity of 84%, sensitivity of 75%, PPV of 56%, NPV of 93% and a good level of inter-observer agreement (k = 0.79). CONCLUSION: The complete fluid filling is the only significant pathological MRI sign for ramp lesions, with moderate accuracy.

Description and ultrasound targeting of the origin of the suprascapular nerve.

Anatomical variations in the suprascapular nerve (SSN) and its depth in the suprascapular notch can make it difficult to target with ultrasonography (US). One alternative could be a proximal approach to the SSN, if US provides a reliable description of its origin (orSSN). The primary objective of this study was to demonstrate that US can reliably locate the orSSN. The secondary objective was to describe the features of the proximal SSN. Seventy brachial plexuses (BPs) from 30 healthy volunteers (60 BPs) and 5 cadavers (10 BPs) were included. There were two parts to this study: (1) description of the proximal SSN in healthy volunteers using US to determine the diameter, depth and location of the orSSN; (2) targeting of the orSSN with US in cadaver limbs to determine its distance from the needle, ink marking and locating the orSSN. In Part I, the diameter of the orSSN averaged 1.33 mm (1-9 mm) and its depth averaged 5.12 mm (2.7-10.6 mm). The orSSN was located in the upper trunk of the BP (53) or its posterior division (7). In Part II, the orSSN was successfully targeted in nine of the 10 specimens by US; the needle/orSSN distance averaged 3.8 mm (0-8 mm). The implanted needle was at the orSSN in two cases, proximal to it in seven and distal to it in one. US is a valid modality for describing and pinpointing the orSSN, irrespective of patient morphology. Clin. Anat. 30:747-752, 2017. © 2017Wiley Periodicals, Inc.

SHANK3 mutations identified in autism lead to modification of dendritic spine morphology via an actin-dependent mechanism.

Genetic mutations of SHANK3 have been reported in patients with intellectual disability, autism spectrum disorder (ASD) and schizophrenia. At the synapse, Shank3/ProSAP2 is a scaffolding protein that connects glutamate receptors to the actin cytoskeleton via a chain of intermediary elements. Although genetic studies have repeatedly confirmed the association of SHANK3 mutations with susceptibility to psychiatric disorders, very little is known about the neuronal consequences of these mutations. Here, we report the functional effects of two de novo mutations (STOP and Q321R) and two inherited variations (R12C and R300C) identified in patients with ASD. We show that Shank3 is located at the tip of actin filaments and enhances its polymerization. Shank3 also participates in growth cone motility in developing neurons. The truncating mutation (STOP) strongly affects the development and morphology of dendritic spines, reduces synaptic transmission in mature neurons and also inhibits the effect of Shank3 on growth cone motility. The de novo mutation in the ankyrin domain (Q321R) modifies the roles of Shank3 in spine induction and morphology, and actin accumulation in spines and affects growth cone motility. Finally, the two inherited mutations (R12C and R300C) have intermediate effects on spine density and synaptic transmission. Therefore, although inherited by healthy parents, the functional effects of these mutations strongly suggest that they could represent risk factors for ASD. Altogether, these data provide new insights into the synaptic alterations caused by SHANK3 mutations in humans and provide a robust cellular readout for the development of knowledge-based therapies.

Ultrasonographic anatomy of the long thoracic nerve: A reappraisal using high frequency (24-MHz) probe.

PURPOSE: The purpose of this study was to analyze the potential of ultrasound with a high frequency probe (24-MHz) in the assessment of the long thoracic nerve (LTN) and describe ultrasonographic landmarks that can be used for standardization. MATERIAL AND METHODS: Ultrasonography analysis of the LTN was done on 2 LTNs in a cadaver specimen and then on 30 LTNs in 15 healthy volunteers (12 men, 3 women; mean age, 28.8±3.8 [SD] years; age range: 24-39 years) by two independent radiologists (R1 and R2) using a 24-MHz probe. Interrater agreement was assessed using Kappa test (K) and intraclass correlation coefficient (ICC). RESULTS: In the cadaver, dissection confirmed that the India ink was injected near the LTN in the middle scalene muscle. In volunteers, visibility of the LTN above the clavicle was highly reproducible for the branches arising from C5 (R1: 87% [26/30]; R2: 90% [27/30]; K=0.83) and from C6 (R1: 100% [30/30]; R2: 97% [29/30]; K=0.94). Where the nerve emerged from the middle scalene muscle, the mean diameter was 0.85±0.24 (SD) mm (range: 0.4-1.6mm) for R1 and 0.9±0.23 (SD) mm (range: 0.4-1.7mm) for R2 (ICC: 0.96; 95% CI: 0.92-0.98%). Along the thoracic wall, where LTN run along the lateral thoracic artery, the mean diameter was 0.83±0.19 (SD) mm (range: 0.5-1.27mm) for R1 and 0.89±0.21 (SD) mm (range: 0.6-1.2mm) for R2 (ICC: 0.86; 95% CI: 0.72-0.93%). CONCLUSION: The LTN can be analyzed with ultrasound using high-frequency probe by using the C5 and C6 roots, the middle scalene muscle above the clavicle and the lateral thoracic artery on the chest wall as landmarks.

[Cross-sectional imaging of peripheral involvement in psoriatic arthritis]. / Nouvelle imagerie des atteintes périphériques du rhumatisme psoriasique.

The purpose of this article is to: 1) describe the main plain film, ultrasound and MR imaging features of peripheral involvement in psoriatic arthritis, 2) describe the advantages of ultrasound and MRI at the early stages of the disease; 3) describe how to use MRI and ultrasound in order to assess response to tumor necrosis factor-alpha blocker therapy.

[Pelvic and spinal MR follow-up of multiple myeloma patients after high-dose chemotherapy and autologous peripheral blood stem cell transplant]. / Suivi par IRM pelvi-rachidienne d'une cohorte de patients atteints de myélome multiple, traités par chimiothérapie à haute dose et autogreffe de cellules souches périphériques.

PURPOSE: To evaluate the changes of bone marrow lesions on pelvic and spinal MR in patients with multiple myeloma after high-dose chemotherapy and autologous peripheral blood stem cell transplant. PATIENTS AND METHODS: Pelvic and spinal MR examinations were obtained at presentation (myeloma diagnosis) and 1 year after transplant in 20 patients that were part of a group of 39 patients enrolled in a prospective study. The type of marrow replacement (classified in stages with stage 0: normal; stage 1: salt and pepper; stage 2: focal infiltration; stage 3: diffuse infiltration), the number and size of marrow lesions and the number of vertebral compression fractures were recorded. We have compared the findings prior to and following transplant, with correlation to the response to treatment and the use of biphosphonates. RESULTS: The type of marrow replacement was improved following transplant in 65% of patients (not statistically significant). The number and size of nodules > 20 mm showed significant reduction (p = 0.0224 and p = 0.0237 respectively). Lesions on MR improved in 50% of patients with good response and 75% of patients with poor response to treatment. Patients receiving biphosphonates showed more vertebral compression fractures. CONCLUSION: The evolution of marrow replacing lesions on MR is discordant compared to the biological and clinical response to treatment. Pelvic and spinal MR evaluation at the time of diagnosis does not appear to be a good predictive factor of response to treatment. Biphosphonates do not appear to prevent new vertebral compression fractures. Pelvic and spinal MR provides interesting data in the follow-up of patients with myeloma following autologous transplant, especially in the local evolution of marrow replacing lesions, but our results do not justify its use in routine clinical practice.

PDZ domain suppression of an ER retention signal in NMDA receptor NR1 splice variants.

The NMDA receptor NR1 subunit has four splice variants that differ in their C-terminal, cytoplasmic domain. We investigated the contribution of the C-terminal cassettes, C0, C1, C2, and C2', to trafficking of NR1 in heterologous cells and neurons. We identified an ER retention signal (RRR) in the C1 cassette of NR1, which is similar to the RXR motif in ATP-sensitive K(+) channels (Zerangue et al., 1999). We found that surface expression of NR1-3, which contains C1, is due to a site on the C2' cassette, which includes the terminal 4 amino acid PDZ-interacting domain. This site suppresses ER retention of the C1 cassette and leads to surface expression. These findings suggest a role for PDZ proteins in facilitating the transition of receptors from an intracellular pool to the surface of the neuron.

[Elbow: plain radiographs]. / Coude: radiographies standard.

Plain radiographs usually allow accurate diagnosis. In this paper, the main radiographic projections will be reviewed along with their normal imaging features. In spite of significant advances in imaging of the elbow (multiplanar capabilities of MRI, volumetric CT imaging), conventional radiographs of the elbow remain a firstline imaging technique in the evaluation of disorders of the elbow.

[High resolution MR imaging of the skin: normal imaging features]. / IRM haute résolution de la peau: aspects normaux.

PURPOSE: To describe the qualitative and quantitative MR imaging features of normal skin. MATERIALS AND METHODS: Thirty-one normal subjects underwent MR evaluation on a 1.5 Tesla magnet using a dedicated coil. Several skin sites were evaluated (back at the scapular level, posterior calf and inferior heel). Two pulse sequences were acquired: a SE T1W and a gradient-echo sequence (FIESTA). Qualitative and quantitative analysis was performed for all three sites. RESULTS: In normal subjects, the different skin layers (callus, epidermis, dermis, hypodermis and pilosebaceous follicles) can be separated and measured on MR. Epidermis and hypodermis are hyperintense whereas dermis is hypointense. Our results confirm the presence of qualitative and quantitative variations between different skin regions. In some cases, a differentiation between papillary and reticular dermis can be achieved. Pilosebaceous follicles and the deep vascular network were clearly depicted on the FIESTA sequence. Measurements for each skin layer were compared based on sex, site and MR pulse sequence. CONCLUSION: MRI provides evaluation of the different skin layers, epidermis, dermis, and hypodermis, and their different components.

[Shoulder radiography: useful radiographic views in current practice]. / Radiographies de l'épaule: les incidences utiles en pratique courante.

The purposes of this paper are: 1) to review the different radiographic projections commonly used to explore shoulder pathology; 2) to propose a practical approach for radiographic evaluation of the shoulder, adapted to the main clinical situations; 3) to recognize the different imaging features of the most frequent shoulder diseases.

[Imaging of traumatic injuries of the shoulder]. / Imagerie des traumatismes de l'épaule.

The goals of this article are: 1) to review the different radiographic projections commonly used at the time of initial imaging evaluation of patients presenting with traumatic injuries of the shoulder; 2) to review the indications and findings of cross-sectional imaging modalities in the assessment of shoulder trauma; 3) to recognize the main anatomical lesions secondary to traumatic injuries of the shoulder.

[Shoulder pain: image guided management]. / Douleur de l'épaule: apport de la radiologie interventionnelle.

Different interventional radiology techniques used in the management of the painful shoulder will be reviewed in this article. The etiology of shoulder pain is variable, and several image guided procedures are available, from simple to more complex. US and fluoroscopy guided intra-articular and bursal infiltration techniques will be described. Percutaneous needle removal of calcific deposits and capsular distension/infiltration of adhesive capsulitis will be discussed. Cysts in the spinoglenoid or suprascapular notch may cause impingement of the suprascapular nerve and may be aspirated under US guidance. Finally, percutaneous radio-frequency treatment of symptomatic bone metastases under CT guidance may at times be performed. Musculoskeletal radiologists should be familiar with this spectrum of image guided interventional procedures.

Ultrasonography study of the suprascapular nerve.

PURPOSE: The aim of the study was to evaluate the assessability of the suprascapular nerve (SSN) by ultrasonography in cadavers and healthy volunteers. MATERIALS AND METHODS: With ultrasonography guidance, needles were placed at origin of the SSN of four cadavers and evaluated by dissection. Two blinded radiologists performed 60 ultrasonography scans in 30 healthy volunteers to study the entire SSN at five anatomical landmarks. RESULTS: Dissection revealed that the needles were correctly located at the nerve's origin. There were no significant differences between the two radiologists' measurements of nerve size and depth. The interobserver correlation for the description of the nerve at the five predefined anatomical landmarks was very good (ICC=0.7-1). CONCLUSION: Five anatomical landmarks were used to analyze the SSN with ultrasonography. Its supraclavicular portion was easier to describe than its scapular portion; a segment of the SSN was not visible between these two portions.

Scedosporium apiospermum mycetoma with bone involvement successfully treated with voriconazole.

Treatment of Scedosporium apiospermum mycetoma usually requires limb amputation. A 49-year-old woman, from Ivory Coast, was diagnosed with Madura foot in 1995. She failed to respond to several treatments including itraconazole, fluconazole and co-trimoxazole, and refused limb amputation. In December 2002 she was admitted to hospital in France with a painful, swollen right leg and foot. She had no fever and C-reactive protein was 120 mg/l. Magnetic resonance imaging (MRI) confirmed the destruction of tarsus bones with a tibia extension. Voriconazole (400 mg/day) treatment was initiated in March 2003; a significant clinical improvement was observed within 4 months as confirmed by C-reactive protein (16 mg/l) and MRI. Voriconazole was maintained for 18 months with good tolerance. Cholestasis appeared after the first month and remained stable. In October 2004 voriconazole was discontinued due to side effects on the liver (alanine aminotransferase 17 times the normal level); MRI showed impressive regression of bone lesions. As of July 2005, the patient remains clinically well. Voriconazole appears to be a promising drug for the treatment of S. apiospermum mycetomas.

[Use of SSFSE sequence for cine-MRI of the cervical spine in professional front-line rugby players]. / Utilisation de la séquence SSFSE pour la Ciné-IRM du rachis cervical du rugbyman professionnel de première ligne.

A SSFSE sequence is proposed in the sagittal plane for a cine-MRI of the cervical spine in front-line rugby players. Thus one can complete the static study and improve the detection of canal stenosis and the prevention of spinal cord injuries.

[Ultrasound features of entesopathy in patients with psoriatic dactylitis]. / Signes échographiques d'enthésopathies au cours des dactylites psoriasiques.

PURPOSE: To describe the sonographic features of entesopathy in patients with psoriatic dactylitis. Materials and methods. Clinical, radiographic and sonographic evaluation of 120 hand joints with clinical abnormality including 20 fingers in 17 patients with rheumatoid arthritis (RA) and 20 fingers in 17 patients with psoriatic arthritis (PA). RESULTS: Forty cases of dactylitis. In patients with RA: 29 cases of synovitis, 15 cases of tenosynovitis, and 2 cases of tendinitis; in patients with PA: 21 cases of synovitis and 3 cases of tenosynovitis. Bone erosions were present in RA patients whereas erosions with bone production were present in PA patients. A total of 60% of RA and PA patients showed erosions on conventional radiographs. Features suggesting entesopathy were present in PA patients only: specific changes of P3, capsular hyperostosis and periarticular periostitis. CONCLUSION: Based on evaluation of PA patients, it seems that sonographic features suggesting entesopathy in patients with dactylitis may be present.

Imaging of meniscus and ligament injuries of the knee.

Magnetic resonance imaging has now an indisputable role for the diagnosis of meniscus and ligament injuries of the knee. Some technical advances have improved the diagnostic capabilities of magnetic resonance imaging so that diagnoses, which may change the therapeutic approach, such as a partial tear of the anterior cruciate ligament or confirmation of unstable meniscal injuries, are now made easier. This article describes the essential about magnetic resonance imaging technique and pathological results for the menisci, collateral ligaments and damage to the central pivot of the cruciate knee ligaments.

Imaging of traumatic injury and impingement of anterior knee fat.

Fat is not just used by the body as bulk tissue. In addition to its role in storing energy and regulating hormone action, fat is used in some parts of the body for its mechanical properties. The anatomy of anterior knee fat is more complex than it appears at first sight and is capable of withstanding considerable compressive and shear stress. Specific lesions occur when such mechanical stress exceeds the physiological limits and are yet little known. Superficial fat can be the site of either acute injury by closed degloving called the Morel-Lavallée lesion or chronic injury, when subject to repeat excessive shear forces, due to more complex and less well-defined disruptions that result in pseudo-bursitis. There are three main anterior, intracapsular and extrasynovial fat pads in the knee joint, which are the infrapatellar fat pad (IFP) or Hoffa's fat pad, the quadriceps fat pad and the prefemoral fat pad. The IFP plays an important role as a mechanical shock absorber and guides the patella tendon and even the patella itself during flexion-extension movements. In response to repeated excessive stress, an inflammatory reaction and swelling of the IFP is first observed, followed by a fibrotic reaction with metaplastic transformation into fibrous, cartilaginous or bone tissue. More rarely, the two other deep fat pads (quadriceps and prefemoral) can, if subject to repeated stress, undergo similar restructuring inflammatory reactions with metaplasia resulting in tissue hardening, anterior pain and partial loss of function.

Bone abnormalities of the knee: MRI features.

The knee is one of the most studied anatomical structures by magnetic resonance imaging (MRI). Bone abnormalities are very frequently detected, whether or not related to the symptoms for which imaging was indicated. The aim of this pictorial study is to review the most commonly observed bone abnormalities of the knee, bearing in mind that the interpretation of MR images should always take into consideration both clinical and laboratory data, as well as the results of conventional X-ray imaging.

Synapse-associated protein 97 selectively associates with a subset of AMPA receptors early in their biosynthetic pathway.

The regulation of AMPA receptors at the postsynaptic membrane is a fundamental component of synaptic plasticity. In the hippocampus, the induction of long-term potentiation increases the delivery of GluR1, a major AMPA receptor subunit in hippocampal pyramidal neurons, to the synaptic plasma membrane through a mechanism that requires the PDZ binding domain of GluR1. Synapse-associated protein 97 (SAP97), a member of the membrane-associated guanylate kinase family, is believed to associate with AMPA receptors (AMPARs) containing the GluR1 subunit, but the functional significance of these interactions is unclear. We investigated the interaction of GluR1 with SAP97, the only PDZ protein known to interact with GluR1. We find that interactions involving SAP97 and GluR1 occur early in the secretory pathway, while the receptors are in the endoplasmic reticulum or cis-Golgi. In contrast, few synaptic receptors associate with SAP97, suggesting that SAP97 dissociates from the receptor complex at the plasma membrane. We also show that internalization of GluR1, as triggered by NMDAR activation, does not require SAP97. These results implicate GluR1-SAP97 interactions in mechanisms underlying AMPA receptor targeting.