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To evaluate the MRI perfusion changes in patients with risk factors for osteonecrosis and normally appearing femoral heads prior to overt femoral head osteonecrosis.Fifty-eight patients (105 hips) were prospectively included in this ethics committee-approved study. There were 46 hips with no image anomalies and no risk factors for osteonecrosis of the femoral head (ONFH) risk factors, 38 with ONFH risk factors and no image abnormalities, and 21 with overt ONFH. All patients underwent DCE-MRI. Semi-quantitative (peak enhancement [PE], area under the curve [AUC], time to maximum enhancement [TME]) and quantitative perfusion parameters (volume plasma, KTRANS, and KEP) were calculated. Excessive alcohol consumption, corticosteroid use, and trauma were considered major risk factors for osteonecrosis of the femoral head.Measured at the femoral neck and compared to the healthy hips without OFNH risk factors, PE was significantly lower in the hips of patients with OFNH risk factors. Moreover, the difference was greater in females with risk factors, who presented significantly lower PE values (p = 0.0096). A PE threshold of 1.4% yielded a 92% sensitivity and 54% specificity for the presence of associated ONFH risk factors. The hips with overt OFNH compared to those with normally appearing showed an increase of PE of 45% in the neck (p0.014). Various epiphyseal femoral head perfusion parameters (PE, TME, AUC, and KDCE-MRI can identify perfusion marrow changes related to the presence of ONFH risk factors and adjacent to osteonecrosis areas.• Bone marrow perfusion changes may occur prior to overt ONFH and extend beyond the osteonecrosis area to the entire femoral head and neck. • Peak enhancement values were significantly reduced in patients with ONFH risk factors, compared to those without. • The presence of ONFH led to a significant increase in marrow perfusion adjacent to the osteonecrosis area.

To study the relationship between opportunistic CT bone density measurements and the occurrence of new vertebral fractures after percutaneous vertebral cementoplasty (PVC) of osteoporotic vertebral compression fractures (OVCF).A prospective analysis of retrospective data of 275 patients with OVCF treated by PVC between 2014 and 2019 with a clinico-radiological follow-up one year after treatment was conducted. Opportunistic bone density measurements were obtained at the trabecular bone of the L1 or an adjacent vertebra in Hounsfield units performed on the preoperative CT study. These density measurements values ​​were then compared between patients with and without new OCVF and in various population subgroups.There were 275 patients included, with 53 (19%) presenting a new OCVF and 24 (9%) developing a fracture cascade. The median opportunistic density measurements ​​in patients with recurrent OCVF were lower than those without (median 52[40.5]) HU and 77[49] HU)(p0.00001). Among the patients with new OVCF the median opportunistic density measurements in patients with fracture cascades were also lower than those without (44 HU and 62 HU, respectively) (p0.0096). Patients with density measurements under 61 HU were 3.6 times more likely to present recurrent fractures and those with density under 54 HU were 9.8 times more likely to develop a fracture cascade. The 36 HU threshold yielded a high specificity (90-91%) for the prediction of recurrent fractures and fracture cascade but with low sensitivity (respectively 26% and 37%).Low opportunistic vertebral density measurements are associated with a higher risk of OVCF and fracture cascades after PVC.• Low opportunistic density measurements are associated with a higher risk of OVCF and fracture cascades after PVC. • Measuring bone density before performing a PVC could help predict the risk of new vertebral fracture after treatment • Patient management could be adapted according to bone density.

To compare the diagnostic performance of scapholunate gap (SLG) measurements acquired with dart throwing (DT), radio-ulnar deviation (RUD), and clenching fist (CF) maneuvers on 4D CT for the identification of scapholunate instability.In this prospective study, 47 patients with suspected scapholunate interosseous ligament (SLIL) tears were evaluated from March 2015 to March 2020 with semiautomatic quantitative analysis on 4D CT. Five parameters (median, maximal value, range, and coefficient of variation) for SLG, lunocapitate angle (LCA), and radioscaphoid angle (RSA) obtained during DT maneuver were evaluated in patients with and without SLIL tears. CT arthrography was used as the gold standard for the SLIL status. The SLG values obtained were also compared with those obtained during CF and RUD maneuvers.Significant differences in all SLG- and LCA-derived parameters are found between patients with and without SLIL tears with DT (p0.003). The best diagnostic performance for the diagnosis of SLIL tears was obtained with median and maximal SLG values (sensitivity and specificity of 86-89% and 95%) and with maximal and range LCA values (sensitivity and specificity of 86% and 74%). No significant differences were observed for RSA values (p0.275). The SLG range obtained with DT maneuver was the only dynamic parameter statistically different between patients with partial and complete torn SLIL (p = 0.037).4D CT of the wrist during DT showed a similar performance than RUD and a better performance than CF for the differentiation between patients with and without SLIL tears.• Four-dimensional computed tomography can dynamically assess scapholunate instability. • The best results for differentiating between patients with and without SLIL tears were obtained with SLG median and maximal values. • The dart throwing and radio-ulnar deviation maneuvers yielded the best results for the dynamic evaluation of scapholunate instability.

To evaluate the image quality and clinical acceptance of a deep learning reconstruction (DLR) algorithm compared to traditional iterative reconstruction (IR) algorithms.CT acquisitions were performed with two phantoms and a total of nine dose levels. Images were reconstructed with two types of IR algorithms, DLR and filtered-back projection. Spatial resolution, image texture, mean noise value, and objective and subjective low-contrast detectability were compared. Ten senior radiologists evaluated the clinical acceptance of these algorithms by scoring ten CT exams reconstructed with the DLR and IR algorithms evaluated.Compared to MBIR, DLR yielded a lower noise and a higher low-contrast detectability index at low doses (CTDIDLR yielded a gain in objective detection and noise at lower dose levels with the best clinical acceptance among the evaluated reconstruction algorithms.• DLR yielded improved objective low-contrast detection and noise at lower dose levels. • Despite the differences in objective detectability among the algorithms evaluated, there were no differences in subjective detectability. • DLR presented significantly higher clinical acceptability scores compared to MBIR and HIR.

Objectives: To ascertain the role of CT and conventional radiographs for the initial characterization of focal bone lesions. Methods: Images from 184 patients with confirmed bone tumors included in an ethics committee-approved study were retrospectively evaluated. The reference for benign-malignant distribution was based on histological analysis and long-term follow-up. Radiographs and CT features were analyzed by 2 independent musculoskeletal radiologists blinded to the final diagnosis. Lesion margins, periosteal reaction, cortical lysis, endosteal scalloping, presence of pathologic fracture, and lesion mineralization were evaluated. Results: The benign-malignant distribution in the study population was 68.5–31.5% (126 benign and 58 malignant). In the lesions that could be seen in both radiographs and CT, the performance of these methods for the benign-malignant differentiation was similar (accuracy varying from 72.8% to 76.5%). The interobserver agreement for the overall evaluation of lesion aggressiveness was considerably increased on CT compared to radiographs (Kappa of .63 vs .22). With conventional radiographs, 18 (9.7%) and 20 (10.8%) of the lesions evaluated were not seen respectively by readers 1 and 2. Among these unseen lesions, 50%–61.1% were located in the axial skeleton. Compared to radiographs, the number of lesions with cortical lysis and endosteal scalloping was 26–34% higher with CT. Conclusion: Although radiographs remain the primary imaging tool for lesions in the peripheral skeleton, CT should be performed for axial lesions. CT imaging can assess the extent of perilesional bone lysis more precisely than radiographs with a better evaluation of lesion fracture risk.

Purpose: To study the anatomy of the latero-lateral joint (LLJ) between the upper lateral (ULC) and lower lateral (LLC) crus of the nasal cartilages, usually described as a scroll articulation. Methodology: Six nasal pyramids were taken in monobloc from fresh cadavers and imaged on micro-MRI with 0.4 mm slice thickness. Images were jointly interpreted by two head and neck radiologists and one surgeon. The junction between the ULC and LLC, the presence of ligaments and of sesamoid or accessory cartilages were assessed. Results: Eight LLJs could be analyzed, with 4 types of junctions: hook-shaped cephalic border of the LLC turned towards the nasal fossa and linear caudal border of the ULC (n=3), hook-shaped caudal border of the ULC and linear cephalic border of the LLC lateral crus (n=1), hook-shaped border of both cartilaginous edges with clinging (n=1) (scroll articulation) or without clinging (n=3). No ligament or sesamoid cartilage was found, but posterior accessory cartilages were seen in 75% of the cases. Conclusion: The classical scroll articulation of the LLJ has been observed in only 1/8 cases on micro-MRI images. The anatomy of the LLJ couldexplain the surgical difficulty in raising the tip of the nose in some patients and not in others.

Hip arthroplasty is a frequently used procedure with high success rates. Its main indications are primary or secondary advanced osteoarthritis, due to acute fracture, osteonecrosis of the femoral head, and hip dysplasia. The goals of HA are to reduce pain and restore normal hip biomechanics, allowing a return to the patient’s normal activities. To reach those goals, the size of implants must suit, and their positioning must meet, quality criteria, which can be determined by preoperative imaging. Moreover, mechanical complications can be influenced by implant size and position, and could be avoided by precise preoperative templating. Templating used to rely on standard radiographs, but recently the use of EOS® imaging and CT has been growing, given the 3D approach provided by these methods. However, there is no consensus on the optimal imaging work-up, which may have an impact on the outcomes of the procedure. This article reviews the current principles of templating, the various imaging techniques used for it, as well as their advantages and drawbacks, and their expected results.

To establish national reference levels (RLs) in interventional procedures under CT guidance as required by the 2013/59/Euratom European Directive. Seventeen categories of interventional procedures in thoracic, abdominopelvic, and osteoarticular specialties (percutaneous infiltration, vertebroplasty, biopsy, drainage, tumor destruction) were analyzed. Total dose length product (DLP), number of helical acquisitions (NH), and total DLP for helical, sequential, or fluoroscopic acquisitions were recorded for 10 to 20 patients per procedure at each center. RLs were calculated as the 3rd quartiles of the distributions and target values for optimization process (TVOs) as the median. RLs and TVOs were compared with previously published studies. Results on 5001 procedures from 49 centers confirmed the great variability in patient dose for the same category of procedures. RLs were proposed for the DLPs and NHs in the seventeen categories. RLs in terms of DLP and NH were 375 mGy.cm and 2 NH for spinal or peri-spinal infiltration, 1630 mGy.cm and 3 NH for vertebroplasty, 845 mGy.cm and 4 NH for biopsy, 1950 mGy.cm and 8 NH for destruction of tumors, and 1090 mGy.cm and 5 NH for drainage. DLP and NH increased with the complexity of procedures. This study was the first nationwide multicentric survey to propose RLs for interventional procedures under CT guidance. Heterogeneity of practice in centers were found with different levels of patient doses for the same procedure. The proposed RLs will allow imaging departments to benchmark their practice with others and optimize their protocols. • National reference levels are proposed for 17 categories of interventional procedures under CT guidance. • Reference levels are useful for benchmarking practices and optimizing protocols. • Reference levels are proposed for dose length product and the number of helical acquisitions.

Background: MRI diagnostic criteria of shoulder adhesive capsulitis (AC) are nowadays widely used, but there is little information available on the association between MRI findings and clinical impairment. Purpose: To determine the correlation of MRI findings with the Constant–Murley Score (CMS), pain duration and symptoms at the one-year follow-up in AC patients. Materials and methods: This monocentric prospective study included 132 patients with a clinical diagnosis of shoulder AC who underwent shoulder MRI. Mean patient age was 54.1 ± 9.3 years, and there were 55 men and 77 women. A radiologist examined all patients and completed the CMS just prior to MRI. Pain duration was assessed along with the signal intensity and measured the maximal thickness of the inferior glenohumeral ligament (IGHL) by two radiologists. Medical record analysis was performed in a sub-group of 49 patients to assess prognosis approximately one year after the MRI examination. Linear regression analysis with the Pearson test and the Fisher exact test were used to determine the association between MRI findings and clinical impairment. Results: There was a significant difference in mean pain duration score (3.8 ± 1.2 versus 3.2 ± 0.9 and 3.8 ± 1.2 versus 3.2 ± 0.9, respectively, for readers 1 and 2) and in mean mobility scores (15.7 ± 8 points versus 19.6 ± 10.1 points and 15.8 ± 8.2 points versus 19.4 ± 10 points, respectively, for readers 1 and 2) in patients with a high IGHL signal compared to those with a low IGHL signal (p &lt, 0.05). IGHL was thicker in patients with clinical improvement at one-year follow-up compared to those presenting clinical stability or worsening (p &lt, 0.05). Conclusions: In patients with shoulder AC, the degree of signal intensity at the IGHL was inversely related to shoulder pain duration and range of motion, and a thickened IGHL indicated a favorable outcome at one-year follow-up.

The original version of this article, published on 02 May 2020, unfortunately contained a mistake.

Summary Purpose The purpose of this study was to evaluate the performance of a deep learning algorithm in detecting abnormalities of thyroid cartilage from computed tomography (CT) examination. Materials and methods A database of 515 harmonized thyroid CT examinations was used, of which information regarding cartilage abnormality was provided for 326. The process consisted of determining image abnormality and, from these preprocessed images, finding the best learning algorithm to appropriately characterize thyroid cartilage as normal or abnormal. CT images were cropped to be centered around the cartilage in order to focus on the relevant area. New images were generated from the originals by applying simple transformations in order to augment the database. Characterizations of cartilage abnormalities were made using transfer learning, by using the architecture of a pre-trained neural network called VGG16 and adapting the final layers to a binary classification problem. Results The best algorithm yielded an area under the receiving operator characteristic curve (AUC) of 0.72 on a sample of 82 thyroid test images. The sensitivity and specificity of the abnormality detection were 83% and 64% at the best threshold, respectively. Applying the model on another independent sample of 189 new thyroid images resulted in an AUC of 0.70. Conclusion This study demonstrates the feasibility of using a deep learning-based abnormality detection system to evaluate thyroid cartilage from CT examinations. However, although promising results, the model is not yet able to match an expert's diagnosis.

Hip arthroplasty (HA) is a frequently used procedure with high success rates, but 7% to 27% of the patients complain of persistent postsurgical pain 1 to 4 years post-operation. HA complications depend on the post-operative delay, the type of material used, the patient’s characteristics, and the surgical approach. Radiographs are still the first imaging modality used for routine follow-up, in asymptomatic and painful cases. CT and MRI used to suffer from metallic artifacts but are nowadays central in HA complications diagnosis, both having their advantages and drawbacks. Additionally, there is no consensus on the optimal imaging workup for HA complication diagnosis, which may have an impact on patient management. After a brief reminder about the different types of prostheses, this article reviews their normal and pathologic appearance, according to each imaging modality, keeping in mind that few abnormalities might be present, not anyone requiring treatment, depending on the clinical scenario. A diagnostic imaging workup is also discussed, to aid the therapist in his imaging studies prescription and the radiologist in their practical aspects.

Identify the most pertinent imaging features for solitary bone tumor characterization using a multimodality approach and propose a systematic evaluation system. Data from a prospective trial, including 230 participants with histologically confirmed bone tumors, typical “do not touch” lesions, and stable chondral lesions, were retrospectively evaluated. Clinical data, CT, and MR imaging features were analyzed by a musculoskeletal radiologist blinded to the diagnosis using a structured report. The benign-malignant distribution of lesions bearing each image feature evaluated was compared to the benign-malignant distribution in the study sample. Benign and malignant indicators were identified. Two additional readers with different expertise levels independently evaluated the study sample. The sample included 140 men and 90 women (mean age 40.7 ± 18.3 years). The global benign-malignant distribution was 67–33%. Seven imaging features reached the criteria for benign indicators with a mean frequency of benignancy of 94%. Six minor malignant indicators were identified with a mean frequency of malignancy of 60.5%. Finally, three major malignant indicators were identified (Lodwick-Madewell grade III, aggressive periosteal reaction, and suspected metastatic disease) with a mean frequency of malignancy of 82.4%. A bone tumor imaging reporting and data system (BTI-RADS) was proposed. The reproducibility of the BTI-RADS was considered fair (kappa = 0.67) with a mean frequency of malignancy in classes I, II, III, and IV of 0%, 2.2%, 20.1%, and 71%, respectively. BTI-RADS is an evidence-based systematic approach to solitary bone tumor characterization with a fair reproducibility, allowing lesion stratification in classes of increasing malignancy frequency. Clinical trial number NCT02895633 . • The most pertinent CT and MRI criteria allowing bone tumor characterization were defined and presented. • Lodwick-Madewell grade III, aggressive periosteal reaction, and suspected metastatic disease should be considered major malignant indicators associated with a frequency of malignancy over 75%. • The proposed evidence-based multimodality reporting system stratifies solitary bone tumors in classes with increasing frequencies of malignancy.

Purpose The purpose of this study was to compare morphologic assessment and relaxometry of patellar hyaline cartilage between conventional sequences (fast spin-echo [FSE] T2-weighted fat-saturated and T2-mapping) and synthetic T2 short-TI inversion recovery (STIR) and T2 maps at 1.5 T magnetic resonance imaging (MRI). Method The MRI examinations of the knee obtained at 1.5 T in 49 consecutive patients were retrospectively studied. There were 21 men and 28 women with a mean age of 45 ± 17.7 (SD) years (range: 18–88 years). Conventional and synthetic acquisitions were performed, including T2-weighted fat-saturated and T2-mapping sequences. Two radiologists independently compared patellar cartilage T2-relaxation time on conventional T2-mapping and synthetic T2-mapping images. A third radiologist evaluated the patellar cartilage morphology on conventional and synthetic T2-weighted images. The presence of artifacts was also assessed. Interobserver agreement for quantitative variables was assessed using intraclass correlation coefficient (ICC). Results In vitro, conventional and synthetic T2 maps yielded similar mean T2 values 58.5 ± 2.3 (SD) ms and 58.8 ± 2.6 (SD) ms, respectively (P = 0.414) and 6% lower than the expected experimental values (P = 0.038). Synthetic images allowed for a 15% reduction in examination time compared to conventional images. On conventional sequences, patellar chondropathy was identified in 35 patients (35/49; 71%) with a mean chondropathy grade of 4.8 ± 4.8 (SD). On synthetic images, 28 patients (28/49; 57%) were diagnosed with patellar chondropathy, with a significant 14% difference (P = 0.009) and lower chondropathy scores (3.7 ± 4.9 [SD]) compared to conventional images. Motion artifacts were more frequently observed on synthetic images (18%) than on conventional ones (6%). The interobserver agreement was excellent for both conventional and synthetic T2 maps (ICC > 0.83). Mean cartilage T2 values were significantly greater on synthetic images (36.2 ± 3.8 [SD] ms; range: 29-46 ms) relative to conventional T2 maps (31.8 ± 4.1 [SD] ms; range: 26-49 ms) (P Conclusion Despite a decrease in examination duration, synthetic images convey lower diagnostic performance for chondropathy, greater prevalence of motion artifacts, and an overestimation of T2 values compared to conventional MRI sequences.

BACKGROUND: To assess the influence on the spatial resolution of various Ultra-high-resolution computed tomography (CT) parameters and provide practical recommendations for acquisition protocol optimization in musculoskeletal imaging. METHODS: All acquisitions were performed with an Ultra-high resolution scanner, and variations of the following parameters were evaluated: field-of-view (150–300 mm), potential (80–140 KVp), current (25–250 mAs), focal spot size (0.4×0.5 to 0.8×1.3 mm(2)), slice thickness (0.25–0.5 mm), reconstruction matrix (512×512 to 2048×2048), and iso-centering (up to 85 mm off-center). Two different image reconstruction algorithms were evaluated: hybrid iterative reconstruction (HIR) and model-based iterative reconstruction (MBIR). CATPHAN 600 phantom images were analyzed to calculate the number of visible line pairs per centimeter (lp/cm). Task transfer function (TTF) curves were calculated to quantitatively evaluate spatial resolution. Cadaveric knee acquisitions were also performed. RESULTS: Under the conditions studied, the factor that most intensely influenced spatial resolution was the matrix size (additional visualization of up to 8 lp/cm). Increasing the matrix from 512×512 to 2048×2048 led to a 28.2% increase in TTF10% values with a high-dose protocol and a 5.6% increase with a low-dose protocol with no change in the number of visually distinguishable line pairs. The second most important factor affecting spatial resolution was the tube output (29.6% TTF10% gain and 5 additional lp/cm visualized), followed by the reconstruction algorithm choice and lateral displacement (both with a 4 lp/cm gain). Decreasing the slice thickness from 0.5 to 0.25 mm, led to an increase of 3 lp/cm (from 17 to 20 lp/cm) and a 17.3% increase in TTF10% values with no change in the “in-plane” spatial resolution. CONCLUSIONS: This study provides practical recommendations for spatial resolution optimization using Ultra-high-resolution CT.

Vascular lesions of the hand are common and are distinct from vascular lesions elsewhere because of the terminal vascular network in this region, the frequent hand exposure to trauma and microtrauma, and the superficial location of the lesions. Vascular lesions in the hand may be secondary to local pathology, a proximal source of emboli, or systemic diseases with vascular compromise. In most cases, ischaemic conditions are investigated with Doppler ultrasonography. However, computed tomography angiography (CTA) or dynamic contrast-enhanced magnetic resonance angiography (MRA) is often necessary for treatment planning. MR imaging is frequently performed with MRA to distinguish between vascular malformations, vascular tumours, and perivascular tumours. Some vascular tumours preferentially affect the hand, such as pyogenic granulomas or spindle cell haemangiomas associated with Maffucci syndrome. Glomus tumours are the most frequent perivascular tumours of the hand. The purpose of this article is to describe the state-of-the-art acquisition protocols and illustrate the different patterns of vascular lesions and perivascular tumours of the hand.

Objectives: MRI diagnostic criteria of shoulder adhesive capsulitis (AC) are widely used, but there is little information available on the association between MRI findings and clinical impairment. The aim of our study was to determine the correlation of MRI findings with the Constant-Murlay Score (CMS), pain duration, and symptoms at the one-year follow-up in AC patients. Methods: MRI of 132 patients with a clinical diagnosis of shoulder AC were prospectively studied. A radiologist examined all patients and completed the CMS just prior to MRI. Pain duration was assessed. The signal intensity and the maximal thickness of the inferior glenohumeral (IGHL) and coracohumeral (CHL) ligaments were measured by two radiologists. Medical record analysis was performed in a sub-group of 49 patients to assess correlation approximately one year after the MRI examination. Results: There was a significant difference in mean pain duration score (3.8 ± 1.2 versus 3.2 ± 0.9 and 3.8 ± 1.2 versus 3.2 ± 0.9 respectively for readers 1 and 2) and in mean mobility scores (15.7 ± 8 points versus 19.6 ± 10.1 points and 15.8 ± 8.2 points versus 19.4 ± 10 points respectively for readers 1 and 2) in patients with a high IGHL signal compared to those with a low signal (P P

International audience; Three-dimensional (3D) imaging and post processing are common tasks used daily in many disciplines. The purpose of this article is to review the new postprocessing tools available. Although 3D imaging can be applied to all anatomical regions and used with all imaging techniques, its most varied and relevant applications are found with computed tomography (CT) data in musculoskeletal imaging. These new applications include global illumination rendering (GIR), unfolded rib reformations, subtracted CT angiography for bone analysis, dynamic studies, temporal subtraction and image fusion. In all of these tasks, registration and segmentation are two basic processes that affect the quality of the results. GIR simulates the complete interaction of photons with the scanned object, providing photorealistic volume rendering. Reformations to unfold the rib cage allow more accurate and faster diagnosis of rib lesions. Dynamic CT can be applied to cinematic joint evaluations a well as to perfusion and angiographic studies. Finally, more traditional techniques, such as minimum intensity projection, might find new applications for bone evaluation with the advent of ultra-high-resolution CT scanners. These tools can be used synergistically to provide morphologic, topographic and functional information and increase the versatility of CT.

A wide variety of pathologies can affect the hallux sesamoid complex of the foot, including traumatic, micro traumatic, degenerative, inflammatory, vascular, infectious, and neoplastic conditions. Symptoms are quite nonspecific, mainly related to pain in the plantar surface of the first metatarsal head. In this context, imaging is important for the etiologic diagnosis of hallux sesamoid complex pathology with implications in patient management. The hallux sesamoid complex has a complex anatomy, and pathologic processes of this region are poorly known of radiologists. Besides, some entities such as "sesamoiditis" remain poorly defined in the literature. Schematically, conditions affecting sesamoids will be divided into two major groups: intrinsic anomalies (sesamoid bone being the center of the pathologic process) and extrinsic anomalies (diseases secondarily involving sesamoid bones). Thus, in this article, after a review of anatomical key points and pathologies affecting the hallux sesamoid complex, a practical multimodality approach for the diagnosis of hallux sesamoid pathologies will be proposed.

To evaluate the use of two alternative picture archiving and communication systems (PACS) interface devices (a graphics tablet and a handheld controller) in clinical practice and on task-oriented exercises. Eleven senior radiologists were prospectively evaluated. The participants used the two tested interface devices for 10 working periods each and answered a questionnaire to evaluate the ergonomics of this experience. The prevalence of work-related musculoskeletal discomfort with the standard PACS interface set (mouse-keyboard-recording device) and these two devices was assessed. Exercises evaluating image scrolling and selection, image zooming and panning, image windowing, performing measurements, and reporting were performed with the standard PACS interface set and with the two tested devices. The sitting posture and hand position were evaluated. The general appreciation of the two alternative interface devices was considered to be similar to that of the standard interface set. The ergonomics of the handheld controller was considered to be slightly better than that of the standard interface set. The prevalence of musculoskeletal discomfort was 81%, 45%, and 18% for the standard interface set, graphics tablet, and handheld controller, respectively. With the graphics tablet and the handheld controller in 45% and 60%, respectively, there was a working posture change with respect to the standard interface set. The mean total exercise completion times of both tested devices were 27% higher than that of the standard interface set. Despite the increase in completion time of the task-oriented exercises, the tested devices were well accepted and considered to be more comfortable than the standard set. • Alternative PACS interface devices can be used as a substitute for the standard mouse-keyboard-recording device set with a potential improvement in work ergonomics and a reduction in work-related musculoskeletal discomfort.

Tomosynthesis is an imaging technique that uses standard X-ray equipment with digital flat panel detectors to create tomographic images from very low-dose projections obtained at different angles. These images are parallel to the plane of the detector. Filtered back-projection or iterative reconstruction algorithms can be used to produce them. Iterative reconstruction used with a metal artifact reduction algorithm reduces metal artifacts, and therefore, improve image quality and in-depth spatial resolution. The radiation dose is lower compared to that of computed tomography and is two to three times the dose of a standard radiography. Tomosynthesis is intended for the analysis of high-contrast structures and especially for bones. It is superior to projection radiography when bone superimpositions are important or when metal structures hide regions of interest. The high in-plane resolution and its ability to perform exams in weight-bearing positioning are some of the main advantages of this technique. The impossible production of perpendicular multiplanar reconstruction and a limited contrast resolution are its main limitations. Tomosynthesis must be considered as an extension or an addition to standard radiography, as it can be performed in the same diagnostic step. The purpose of this article was to describe the principles, advantages and limitations, and current and future applications in musculoskeletal pathology of tomosynthesis.

The objective of this study was to describe the normal variation of bone marrow fat content in the proximal femur considering the influence of side, age, sex and body mass index using fat fraction MRI. From September 2012 to July 2016, the MRI of 131 patients (258 hips) considered to have a normal MRI appearance were retrospectively evaluated. Patient records were searched to allow calculation of the body mass index (BMI). Water-fat based chemical shift MRI was available for all patients included. Proton density fat fraction maps were calculated, and measurements were performed in the femoral epiphysis, intertrochanteric region, and greater trochanter. The influence of patient age, sex, hip side and BMI on fat fraction values was assessed. Fat fraction was significantly different in the different locations evaluated (P = 0.0001). Patient sex and age significantly influenced fat fraction values in all regions evaluated (P

To describe the aspect of the anteromedial meniscofemoral ligament on MRI and to assess its prevalence.One thousand five hundred sixty knee MRI studies were retrospectively evaluated for the presence of an anteromedial meniscofemoral ligament. In addition to these studies, nine full MRI studies from our department's image archive were also analysed. The anteromedial meniscofemoral ligament length, thickness, and angle with respect to the tibial plateau were evaluated independently by two radiologists. For comparison purposes, the anterior cruciate ligament was assessed in the same manner.There was a 0.77% prevalence of the anteromedial meniscofemoral ligament in the study population. Compared to the anterior cruciate ligament, the anteromedial meniscofemoral ligament was 80.6%-83.8% thinner according to both observers (P = 0.0002), with a mean thickness of 1.53 ± 0.47 mm and 1.80 ± 0.66 mm determined by observers 1 and 2, respectively. The anteromedial meniscofemoral ligament angles were 15%-17.7% lower than the anterior cruciate ligament angles (P 0.003). Interobserver reproducibility was considered excellent for the length and angle measurements (ICCs varying from 0.85-0.97) and good for the thickness measurements (ICCs 0.66-0.77).The anteromedial meniscofemoral ligament is a rare structure that can be differentiated from the anterior cruciate ligament based on morphologic criteria.

To study variations in the anatomical relationships of the branches of the ulnar nerve in Guyon’s canal relative to the hamulus of hamate (HH) in a grip encountered among cyclists. Forty-seven wrist examinations were performed on a 3-T MRI (soft antenna, 16 channels) in propeller sequence in the plane perpendicular to the carpus in 28 healthy volunteers in three cycling positions (neutral, hyperextension and ulnar deviation). The positions and distance between the superficial (SB) and deep (DB) branches of the ulnar nerve with respect to the HH were determined on the section passing through the HH. The mean distances between the SB (d s) and DP (d p) and HH were 2.4 and 0.6 mm, respectively. The d s in hyperextension and ulnar deviation were 2.2 mm (P = 0.3) and 3 mm (P = 0.07), respectively. The d p in hyperextension and ulnar deviation were 0.3 mm (P = 0.02) and 0.5 mm (P = 0.15), respectively. Hyperextended, 60 % of SB and 40 % of DB were close to the HH, and 26 % of DB came directly in contact with it. In ulnar deviation, 30 % of SB and 29 % of DB approached HH, and 47 % of DB were in contact with it. This study shows that SB and DB positions of the ulnar nerve vary with respect to the HH depending on the position of the wrist, and such differences may promote Guyon’s canal syndrome in cyclists.

To evaluate the diagnostic performance of digital tomosynthesis (DTS) for the diagnosis of hip prosthesis loosening (PL) compared with conventional radiographs and CT with metal artifact reduction (CT-MAR). Forty-nine patients with painful hip prosthesis were prospectively included and underwent anteroposterior and lateral radiographs, anteroposterior DTS and CT-MAR of the hip. This study was approved by the local ethics committee, and all patients signed an informed consent form. Images were evaluated independently by two radiologists. Periprosthetic radiolucent lines wider than 2 mm found in two or more Gruen or De Lee and Charnley zones were considered diagnostic of PL. All cases of PL were confirmed surgically. Patients with a stable radiological follow-up for at least 1 year with an alternative cause for the symptoms or with no surgical evidence of PL were considered PL negative. There were 21 cases of PL, 9 unilateral and 12 bilateral. For both the acetabular and femoral sides, DTS had a specificity for PL detection similar to that of conventional radiographs and CT-MAR (98.5–100%, 96.9%–100% and 96.9–95.4% respectively for both readers) and a sensitivity similar to conventional radiographs (39.9–45.4% versus 33.3–51.5% for both readers) but lower than CT-MAR (84.85% for both readers). The interobserver agreement was 0.84 for CT-MAR, 0.53 for DTS and 0.39 for conventional radiographs. DTS has a similar diagnostic performance to radiographs for the diagnosis of PL with a better interobserver agreement. The sensitivity however remains lower than that of CT-MAR. • Plain radiograph is still the first imaging step when hip prosthesis loosening is suspected. • Interobserver agreement is better with digital tomosynthesis than radiographs. • Sensitivity of CT with state-of-the-art metal artifact reduction is superior to that of digital tomosynthesis.

Vasculo-nervous structures serving the upper limbs may be compressed as they pass through three areas: the inter-scalene triangle (IST), the costo-clavicular space (CCS) and the retropectoralis minor space (RMS). The diagnosis of thoracic outlet syndrome (TOS) is essentially clinical, but requires imaging to specify the site of compression, its grade and the existence of predisposing anatomical factors, in order to guide the treatment and eliminate the main differential diagnoses.Images from 141 patients who underwent dynamic CT angiography of the thoracic outlets from June 2008 to January 2015 were analyzed retrospectively. Patients had unilateral or bilateral vascular, neurological, mixed or atypical symptoms. We studied the degree of stenosis of the subclavian artery with the following grading system: 1 (0-25%), 2 (25-50%), 3 (50-75%), 4 (75-100%). The site of stenosis and the presence of underlying anatomical predisposing factors were also taken in account.A total of 221 thoracic outlets were analyzed. Symptoms were neurological, mixed, vascular and atypical in 30%, 28%, 13% and 12%, respectively. Among patients with bilateral acquisitions, 38 outlets were asymptomatic; 40% of symptomatic outlets and only 5% of asymptomatic ones had grade 3 or 4 stenosis. 63% of the stenosis were in the CCS and 37% in the IST; 21% had a predisposing anatomical factor most often a costo-clavicular anomaly, associated with significant stenosis in 50% of cases.Vascular stenosis of more than 50% on dynamic CT angiography is strongly associated with TOS. Predisposing factors were present in 21% of cases, causing significant vascular stenosis in half, underscoring the need for functional evaluation.

Introduction L’anesthesie peridurale (APD) est la technique anesthesique de reference pour la prise en charge de la cesarienne lorsqu’une analgesie peridurale a ete precedemment debutee. Cependant, cette technique est souvent associee a une hypotension arterielle secondaire a la survenue du bloc sympathique. L’objectif de ce travail etait d’evaluer les effets d’un « preconditionnement » du blocage sympathique par une dose analgesique d’anesthesique local (AL) sur les effets hemodynamiques constates lors de l’injection ulterieure du meme AL a dose anesthesique pour la realisation d’une cesarienne programmee. Materiel et methodes Il s’agissait d’une etude prospective, randomisee, monocentrique. Toutes les parturientes ayant une indication a la realisation d’une cesarienne programmee par APD ont ete incluses. Deux groupes ont ete constitues : – le groupe « Protocole LONG » dans lequel l’induction de l’anesthesie peridurale etait realisee par 2 injections de 6 mL de ropivacaine 1 mg/mL a 5 minutes d’intervalle puis une administration d’un bolus de 12 mL de ropivacaine 7,5 mg/mL, 30 minutes apres la derniere dose analgesique ; – le groupe « Protocole COURT » dans lequel seul le bolus de 12 mL de ropivacaine 7,5 mg/mL etait realise. Le critere de jugement principal etait le taux d’utilisation d’un protocole standardise de neosynephrine, de la pose de l’APD jusqu’a l’extraction fœtale, reposant sur des variations hemodynamiques predeterminees et evaluees par la pression arterielle non invasive toutes les 2 minutes et demi et la frequence cardiaque analysee en continue. Les criteres de jugement secondaire etaient la quantite de neosynephrine administree, le niveau anesthesique obtenu, la necessite d’une reinjection d’AL et les repercussions neonatales. Le nombre de 32 patientes a inclure a ete calcule sur la base d’un test exact de Fisher. L’analyse statistique a ete realisee a l’aide d’un test de Mann-Whitney et d’une analyse de variance de deux facteurs a mesures repetees. Cette etude a recu l’avis favorable du Comite de protection des personnes. Resultats De juillet a novembre 2014, 32 patientes ont ete incluses. Le protocole neosynephrine a ete utilise chez 62,5 % des patientes dans le groupe Protocole COURT et chez 56,25 % des patientes dans le groupe Protocole LONG (p = ns). Il n’y avait pas de difference significative entre les 2 groupes pour les valeurs des differents parametres hemodynamiques. En revanche, les quantites de neosynephrine administrees en cas d’hypotension arterielle etaient significativement plus basses dans le groupe protocole long (90 μg ± 60) par rapport au protocole court (150 μg ± 90) (**p = 0,0057). Le niveau sensitif obtenu ne differait pas significativement entre les 2 groupes ( Fig. 1 ). Discussion Meme si un « preconditionnement » du blocage sympathique lors de l’induction d’une APD ne permet pas de diminuer le recours a un protocole de neosynephrine lors d’une cesarienne programmee, le retentissement hemodynamique semble plus limite au vue des doses moindres utilisees dans le groupe « Protocole LONG ». Une evaluation en continu des parametres hemodynamiques elargis au debit cardiaque par un monitorage non invasif de l’analyse de pouls portant sur un collectif plus important permettrait de confirmer cette constatation.

This study investigated the gene expression profile of human mesenchymal stem cells seeded in collagen sponge for 28 days in three different mediums: (1) basal medium as control containing ITS alone, (2) ITS+TGF-β1 alone or (3) ITS 1% supplemented sequentially by TGF-β1 (D3-D14) followed by BMP-2 (D15-D28). Differential expression of 84 genes implicated in chondrogenic and osteogenic differentiation of MSCs was analyzed at D28 by real-time RT-PCR array technology. TGF-β1 alone down-regulated two genes, CD36 and cathepsin K. Sixteen genes were significantly up-regulated, notably type 2 and type 10 collagens, COMP and Sox9. The sequential combination of TGF-β1 and BMP-2 produced a similar profile with prominent expression of type 2 collagen and the alkaline phosphatase gene. Interestingly, in this in vitro condition, RUNX2 was not up-regulated, suggesting that the sequential combination of TGF-β1/BMP2 enhances the hypertrophic chondrogenic profile without turning towards the osteoblastic pathway.