Founder's lecture of the ISS 2006: borderlands of normal and early pathological findings in MRI of the foot and ankle

The purpose of this article is to highlight the anatomical variants, technical pitfalls, and the prevalence of abnormal conditions in the asymptomatic population in magnetic resonance imaging of the foot and ankle. Special attention is drawn to the complex anatomy of the deltoid ligament (the superficial tibionavicular ligament, tibiospring ligament, the tibiocalcaneal ligament, and the deep anterior and posterior tibiotalar ligaments) and the posterior tibial tendon insertion including the magic angle artifact and the high prevalence of asymptomatic findings such as "hypertrophied” peroneal tubercle (abnormal only when larger than 5mm), peroneus quartus (prevalence 17%), and cysts (vascular remnants) just inferior to the angle of Gissan

Snake and spider toxins induce a rapid recovery of function of botulinum neurotoxin paralysed neuromuscular junction

Botulinum neurotoxins (BoNTs) and some animal neurotoxins (-Bungarotoxin, -Btx, from elapid snakes and -Latrotoxin, -Ltx, from black widow spiders) are pre-synaptic neurotoxins that paralyse motor axon terminals with similar clinical outcomes in patients. However, their mechanism of action is different, leading to a largely-different duration of neuromuscular junction (NMJ) blockade. BoNTs induce a long-lasting paralysis without nerve terminal degeneration acting via proteolytic cleavage of SNARE proteins, whereas animal neurotoxins cause an acute and complete degeneration of motor axon terminals, followed by a rapid recovery. In this study, the injection of animal neurotoxins in mice muscles previously paralyzed by BoNT/A or /B accelerates the recovery of neurotransmission, as assessed by electrophysiology and morphological analysis. This result provides a proof of principle that, by causing the complete degeneration, reabsorption, and regeneration of a paralysed nerve terminal, one could favour the recovery of function of a biochemically- or genetically-altered motor axon terminal. These observations might be relevant to dying-back neuropathies, where pathological changes first occur at the neuromuscular junction and then progress proximally toward the cell body

Lactate and T 2 measurements of synovial aspirates at 1.5T: differentiation of septic from non-septic arthritis

Objective: The aim of this study was to differentiate septic from non-septic arthritis by measuring lactate concentration with 1H magnetic resonance spectroscopy (HMRS) and by estimating total protein content with the assessment of T 2 values. Materials and methods: In 30 patients with acute arthritis, synovial fluid was aspirated. Lactate concentrations were analyzed with single voxel HMRS at 1.5T. T 2 relaxation times were mapped with a multi-spin echo sequence. All samples underwent microbiological testing and routine laboratory analysis to quantify lactate concentration and total protein content. Values obtained in septic and non-septic arthritis were compared with a Mann-Whitney U test. Results: Synovial fluid from patients with septic arthritis (n = 10) had higher concentrations of lactate (11.4 ± 4.0mmol/L) and higher total protein content (51.8 ± 10.7g/L) than fluid obtained in non-septic arthritis (n = 20; 5.2 ± 1.1mmol/L and 40.4 ± 6.9g/L, respectively, p 6mmol/L) in combination with low T 2 values (<550ms) identify septic arthritis with a sensitivity of 70% and a specificity of 89%. Conclusion: Spectroscopic measurements of lactate concentration in combination with the estimation of protein content using T 2 may be of value in the differentiation of septic from non-septic arthriti

CT-guided cervical nerve root injections: comparing the immediate post-injection anesthetic-related effects of the transforaminal injection with a new indirect technique

Objective: To describe an "indirect” cervical nerve root injection technique with a dorsal approach that should carry less inherent risk than the "direct” cervical transforaminal injection approach, and to compare the immediate post-injection results of the two procedures. Materials and methods: The indirect and direct cervical nerve root injection procedures are described in detail. Fifty-three consecutive patients receiving the indirect nerve root injections during 2009-2010 were age- and gender-matched to 53 patients who underwent direct transforaminal nerve root injections performed in 2006. Pain level data were collected immediately before and 20-30min after each procedure. The percentages of pain change in the two groups were compared using the unpaired Student'st test. Results: Fifty-two men (mean age 49) and 54 women (mean age 55) were included. The mean percentage of pain reduction for patients receiving indirect nerve root injections was 38.4% and for those undergoing the direct nerve root injections approach it was 43.2%. This was not significantly different (P = 0.455). No immediate or late adverse effects were reported after either injection procedure. Conclusions: The indirect cervical nerve root injection procedure is a potentially safer alternative to direct cervical transforaminal nerve root injections. The short-term pain reduction is similar using the two injection method

Role of MR imaging in chronic wrist pain

Magnetic resonance (MR) imaging for chronic wrist pain is challenging. Correct assessment of the triangular fibrocartilage, hyaline cartilage, ligaments, and tendons has become mandatory for comprehensive decision making in wrist surgery. The MR technique, potential and limits of MR imaging in patients with chronic wrist pain will be discussed. MR arthrography with injection of gadolinium-containing contrast material into the distal radioulnar joint is suggested for evaluation of the triangular fibrocartilage. The clinically meaningful ulnar-sided peripheral tears are otherwise hard to diagnose. The diagnostic performance of MR imaging for interosseous ligament tears varies considerably. The sensitivity for scapholunate ligament tears is consistently better than for lunotriquetral ligament tears. Gadolinium-enhanced MR imaging is considered to be the best technique for detecting established avascularity of bone, but the assessment of the MR results remains challenging. Most cases of ulnar impaction syndrome have characteristic focal signal intensity changes in the ulnar aspect of the lunate. Avascular necrosis of the lunate (Kienböck's disease) is characterized by signal changes starting in the proximal radial aspect of the lunate. MR imaging is extremely sensitive for occult fractures. Questions arise if occult posttraumatic bone lesions seen on MR images only necessarily require the same treatment as fractures evident on plain films or computed tomography (CT) images. MR imaging and ultrasound are equally effective for detecting occult carpal ganglia. Carpe bossu (carpal boss) is a bony protuberance of a carpometacarpal joint II and III which may be associated with pai

Ultrasound for the evaluation of femoroacetabular impingement of the cam type. Diagnostic performance of qualitative criteria and alpha angle measurements

Objective: To develop and assess a technique to evaluate cam type femoroacetabular impingement (FAI) using ultrasound (US). Methods: Fifty patients (24 women, 26 men) were included (mean age: 39.1years; age range: 16-59). US images of the anterior and anterosuperior contour of the femoral neck were obtained and analysed in 50 patients. Non-spherical shape of the head-neck junction (cam deformity), bony protuberances at the femoral neck, shape of the femoral neck (waist deficiency) and alpha angle were assessed. Magnetic resonance (MR) arthrography served as the standard of reference. Diagnostic performance and receiver operating characteristics (ROC) curves were calculated. Results: Based on MR arthrography 28 patients had cam-type FAI. On US, an anterosuperior cam deformity was seen in 40/44 patients (Reader 1/Reader 2; sensitivity 93%/89%, specificity 36%/14%). A bony protuberance anterosuperiorly in 23/13 patients (sensitivity 71%/32%, specificity 86%/82%) and an anterosuperior waist deficiency in 19/35 patients (sensitivity 25%/54%, specificity 100%/54%). Sensitivity and specificity of the other criteria were lower than 70% (average of Reader 1 & 2). Conclusion: A technique to evaluate cam type FAI using US is presented. The detection of an anterosuperior cam deformity is sensitive, and presence of an anterosuperior bony protuberance is specific for cam FAI. Alpha angle measurements are not helpful in establishing the diagnosi

Improved visualization of collateral ligaments of the ankle: multiplanar reconstructions based on standard 2D turbo spin-echo MR images

The purpose of the study was to evaluate the visualization of the collateral ankle ligaments on multiplanar reconstructions (MPR) based on standard 2D turbo spin-echo images. Coronal and axial T2-weighted turbo spin-echo and MPR angled parallel to the course of the ligaments of 15 asymptomatic and 15 symptomatic ankles were separately analyzed by two musculoskeletal radiologists. Image quality was assessed in the asymptomatic ankles qualitatively. In the symptomatic ankles interobserver agreement and reader confidence was determined for each ligament. On MPR the tibionavicular and calcaneofibular ligaments were more commonly demonstrated on a single image than on standard MR images (reader 1: 13 versus 0, P=0.002; reader 2: 14 versus 1, P=0.001 and reader 1: 13 versus 2, P=0.001; reader 2: 14 versus 0, P<0.001). The tibionavicular ligament was considered to be better delineated on MPR by reader 1 (12 versus 3, P=0.031). In the symptomatic ankles, reader confidence was greater with MPR for all ligaments except for the tibiocalcanear ligament (both readers) and the anterior and posterior talofibular ligaments (for reader 2). Interobserver agreement was increased with MPR for the tibionavicular ligament. Multiplanar reconstructions of 2D turbo spin-echo images improve the visualization of the tibionavicular and calcaneofibular ligaments and strengthen diagnostic confidence for these ligament

The impact of IoT technologies on product-oriented PSS: The 'home delivery' service case

The contribution aims to evaluate the impact that IoT technologies can have on PSS and services. Particularly, the analysis considers two dimensions: the typology of services enabled by the IoT, and the PSS lifecycle phases of the home delivery. By means of multiple use cases, authors found out that IoT technologies have huge impacts both on order placement and delivery phases. Particularly, they have a two-fold advantage for the main stakeholders involved: on one side they speed up operations and on the other they reduce the number of activities for completing the overall home delivery process