An anatomical study of the indirect tendon of the rectus femoris using ultrasonography.

UNLABELLED: The aim of this study was to demonstrate that ultrasound can allow a precise assessment of the indirect tendon of the rectus femoris using a new lateral approach. METHODS AND MATERIALS: Four hips were dissected for the anatomical study of the proximal rectus femoris insertions. Under ultrasonographic guidance, spinal needles piercing the direct tendon were placed in the indirect tendon, following by dissection. Then, high-resolution ultrasound was performed in 20 volunteers with assessment of the indirect tendon of the rectus femoris. RESULTS: At dissection, the spinal needles were located in or immediately adjacent to the indirect tendon, thus confirming that it was correctly depicted by ultrasound. The indirect tendon could be identified in each cadaver and each volunteer with ultrasound. The optimal position of the probe to allow assessment of the indirect tendon could be defined. No significant changes in the appearance or thickness of the tendon could be observed. CONCLUSION: The results of our study showed that the indirect tendon of the rectus femoris muscle can be clearly depicted by sonography in healthy adult subjects. The potential applications of this new use of sonography must now be confirmed by clinical studies. KEY POINTS: • The anatomy of the proximal rectus femoris is reviewed • Until now, sonography was limited for assessing direct and conjoined tendons • The indirect tendon can be clearly depicted by sonography • A new lateral approach for studying the indirect tendon is described.

Pisotriquetral joint disorders: an under-recognized cause of ulnar side wrist pain.

Pisotriquetral joint disorders are often under-recognized in routine clinical practice. They nevertheless represent a significant cause of ulnar side wrist pain. The aim of this article is to present the main disorders of this joint and discuss the different imaging modalities that can be useful for its assessment.

[Spinal infections: typical and atypical imaging features]. / Infections rachidiennes: aspects typiques et atypiques.

While the imaging features of established spondylodiscitis are well known, other presentations may be misleading. The purpose of this article is to review the typical imaging features of spondylodiscitis as well as some more atypical and unusual imaging features (early spondylodiscitis, sceptic spondylitis, septic arthritis of facet joints, primary epidural abscess, unusual germs, neonate).

Three artificial intelligence data challenges based on CT and MRI.

PURPOSE: The second edition of the artificial intelligence (AI) data challenge was organized by the French Society of Radiology with the aim to: (i), work on relevant public health issues; (ii), build large, multicentre, high quality databases; and (iii), include three-dimensional (3D) information and prognostic questions. MATERIALS AND METHODS: Relevant clinical questions were proposed by French subspecialty colleges of radiology. Their feasibility was assessed by experts in the field of AI. A dedicated platform was set up for inclusion centers to safely upload their anonymized examinations in compliance with general data protection regulation. The quality of the database was checked by experts weekly with annotations performed by radiologists. Multidisciplinary teams competed between September 11th and October 13th 2019. RESULTS: Three questions were selected using different imaging and evaluation modalities, including: pulmonary nodule detection and classification from 3D computed tomography (CT), prediction of expanded disability status scale in multiple sclerosis using 3D magnetic resonance imaging (MRI) and segmentation of muscular surface for sarcopenia estimation from two-dimensional CT. A total of 4347 examinations were gathered of which only 6% were excluded. Three independent databases from 24 individual centers were created. A total of 143 participants were split into 20 multidisciplinary teams. CONCLUSION: Three data challenges with over 1200 general data protection regulation compliant CT or MRI examinations each were organized. Future challenges should be made with more complex situations combining histopathological or genetic information to resemble real life situations faced by radiologists in routine practice.

[Value of imaging in posterolateral corner injuries of the knee]. / Apport de l'imagerie dans les lésions du point d'angle postéro-latéral du genou.

Lesions of the posterolateral corner are usually post-traumatic in etiology. They are most frequently associated with tear of the ACL and/or PCL. When unrecognized, they may lead to short-term failure of cruciate ligament reconstruction or long-term knee joint degeneration. Early detection of such lesions, especially in the preoperative period, is important since more severe injuries usually require dedicated early surgical management. The anatomy of the posterolateral corner will be reviewed and the normal and abnormal imaging features on MRI and US will be illustrated. The main clinical and surgcal features will also be presented.

Impact of the rise of artificial intelligence in radiology: What do radiologists think?

PURPOSE: The purpose of this study was to assess the perception, knowledge, wishes and expectations of a sample of French radiologists towards the rise of artificial intelligence (AI) in radiology. MATERIAL AND METHOD: A general data protection regulation-compliant electronic survey was sent by e-mail to the 617 radiologists registered in the French departments of Nord and Pas-de-Calais (93 radiology residents and 524 senior radiologists), from both public and private institutions. The survey included 42 questions focusing on AI in radiology, and data were collected between January 16th and January 31st, 2019. The answers were analyzed together by a senior radiologist and a radiology resident. RESULTS: A total of 70 radiology residents and 200 senior radiologists participated to the survey, which corresponded to a response rate of 43.8% (270/617). One hundred ninety-eight radiologists (198/270; 73.3%) estimated they had received insufficient previous information on AI. Two hundred and fifty-five respondents (255/270; 94.4%) would consider attending a generic continuous medical education in this field and 187 (187/270; 69.3%) a technically advanced training on AI. Two hundred and fourteen respondents (214/270; 79.3%) thought that AI will have a positive impact on their future practice. The highest expectations were the lowering of imaging-related medical errors (219/270; 81%), followed by the lowering of the interpretation time of each examination (201/270; 74.4%) and the increase in the time spent with patients (141/270; 52.2%). CONCLUSION: While respondents had the feeling of receiving insufficient previous information on AI, they are willing to improve their knowledge and technical skills on this field. They share an optimistic view and think that AI will have a positive impact on their future practice. A lower risk of imaging-related medical errors and an increase in the time spent with patients are among their main expectations.

Artificial intelligence to diagnose meniscus tears on MRI.

PURPOSE: The purpose of this study was to build and evaluate a high-performance algorithm to detect and characterize the presence of a meniscus tear on magnetic resonance imaging examination (MRI) of the knee. MATERIAL AND METHODS: An algorithm was trained on a dataset of 1123 MR images of the knee. We separated the main task into three sub-tasks: first to detect the position of both horns, second to detect the presence of a tear, and last to determine the orientation of the tear. An algorithm based on fast-region convolutional neural network (CNN) and faster-region CNN, was developed to classify the tasks. The algorithm was thus used on a test dataset composed of 700 images for external validation. The performance metric was based on area under the curve (AUC) analysis for each task and a final weighted AUC encompassing the three tasks was calculated. RESULTS: The use of our algorithm yielded an AUC of 0.92 for the detection of the position of the two meniscal horns, of 0.94 for the presence of a meniscal tear and of 083 for determining the orientation of the tear, resulting in a final weighted AUC of 0.90. CONCLUSION: We demonstrate that our algorithm based on fast-region CNN is able to detect meniscal tears and is a first step towards developing more end-to-end artificial intelligence-powered diagnostic tools.

Automatic knee meniscus tear detection and orientation classification with Mask-RCNN.

PURPOSE: This work presents our contribution to a data challenge organized by the French Radiology Society during the Journées Francophones de Radiologie in October 2018. This challenge consisted in classifying MR images of the knee with respect to the presence of tears in the knee menisci, on meniscal tear location, and meniscal tear orientation. MATERIALS AND METHODS: We trained a mask region-based convolutional neural network (R-CNN) to explicitly localize normal and torn menisci, made it more robust with ensemble aggregation, and cascaded it into a shallow ConvNet to classify the orientation of the tear. RESULTS: Our approach predicted accurately tears in the database provided for the challenge. This strategy yielded a weighted AUC score of 0.906 for all three tasks, ranking first in this challenge. CONCLUSION: The extension of the database or the use of 3D data could contribute to further improve the performances especially for non-typical cases of extensively damaged menisci or multiple tears.

[Plain radiographs of the wrist and hand]. / Les radiographies simples du poignet et de la main.

The purpose of this review is to describe the value of the different radiographic projections of the wrist and hand, provide criteria for quality control and key interpretation points. Plain radiographs of the hand and wrist are still, in this era of cross-sectional imaging, of great importance in the assessment and understanding of bone and joint disorders, particularly in the setting of trauma. Indeed postero-anterior and lateral views have to be completed with additional projections depending on the suspected lesion and clinical presentation.

Perfusion MR imaging at 3-Tesla: Can it predict tumor grade and histologic necrosis rate of musculoskeletal sarcoma?

PURPOSE: To identify quantitative perfusion parameters that are best associated with tumor grade and tumor necrosis at magnetic resonance (MR) imaging at 3-Tesla. METHODS: MR perfusion studies of 31 patients with a musculoskeletal sarcoma were retrospectively evaluated by two readers. There were 18 men and 13 women with a mean age of 34.9±24.4 (standard deviation [SD] years) (range: 6-87 years). All patients underwent carcinologic tumor resection less than 3 months after MR imaging. For all patients six perfusion parameters (three semi-quantitative and three permeability parameters) were analyzed. The percentage of tumor necrosis was estimated using MR imaging. Perfusion data were compared between groups of tumors with different grades and necrosis ratios. Interobserver variability was calculated using intraclass correlation coefficient (ICC). RESULTS: Interobserver variability among the perfusion parameters was good to excellent (ICC: 0.72-0.9). The area under the curve and maximum slope values showed a significant association with the degree of tumor necrosis (P=0.02-0.04). When tumors with low necrosis ratios were compared to those with high ratios the former parameter was 80% lower. In the same groups, the imaging necrosis index was 56.9-59.8% higher in patients with grade 2 necrosis (P=0.01). Extracellular space volume (Ve) was 31.4% to 55.8% lower in tumors with high grade while the backflow constant (Kep) was 33.6% to 40.1%% higher in tumors with high grade. CONCLUSION: Semi-quantitative MR perfusion parameters have an excellent reproducibility and are associated with the degree of histologic tumor necrosis in musculoskeletal sarcomas. The utility of permeability parameters for determining tumor grade needs further investigations.

Results and limitations of humeral head resurfacing: 105 cases at a mean follow-up of 5 years.

BACKGROUND: The objective of this study was to assess clinical and computed-tomography (CT) outcomes at least 2 years after humeral head resurfacing to treat concentric gleno-humeral osteoarthritis. HYPOTHESIS: Humeral head resurfacing provides similar outcomes to those achieved with stemmed humeral head implants. MATERIALS AND METHODS: This single-centre retrospective study included 40 Copeland™ and 65 Aequalis™ humeral resurfacing heads implanted between 2004 and 2012. Mean patient age at diagnosis was 64 years. The diagnoses were osteoarthritis with an intact (68%) or torn (21%) rotator cuff, avascular necrosis (5%), osteoarthritis complicating chronic instability (3%), post-traumatic osteoarthritis (2%), and chronic inflammatory joint disease (1%). Validated clinical scores, radiographs, and CT before surgery and at last follow-up were compared. RESULTS: During the mean follow-up of 56 months, complications occurred in 24 implants. Revision surgery with reverse shoulder replacement was required in 18 cases, after a mean of 43.6 months, to treat glenoid wear or a rotator cuff tear. At last follow-up, for the implants that did not require revision surgery, the mean Constant score was 64/100. The implants had a mean varus of 5° and mean retroversion of -13.3°. The mean increase in glenoid cavity depth was 2.4mm. Mean increases in medial and lateral humeral offset were 1.9mm and 2.7mm, respectively. Pre-operative factors significantly associated with failure were rotator cuff tear (P=0.017) and glenoid erosion (P=0.001). DISCUSSION: We found a high failure rate related to glenoid wear or progressive rotator-cuff impairment, although CT showed no evidence of implant malposition or overstuffing. Previous studies of stemmed humeral head implants showed better outcomes. Given the low medium-term prosthesis survival rate, we now reserve humeral head resurfacing for concentric osteoarthritis without glenoid erosions or rotator cuff damage. LEVEL OF EVIDENCE: IV, retrospective study.

A specific clinical pattern of camptocormia in Parkinson's disease.

BACKGROUND: Camptocormia, characterised by extreme forward flexion of the thoracolumbar spine and severe stooping in the supine position, seems to be prevalent in Parkinson's disease. OBJECTIVE: The aim of this study was to identify features of parkinsonian camptocormia and to describe the main clinical characteristics of patients with Parkinson's disease who develop the condition. METHODS: An extensive range of clinical, biochemical and imaging data were gathered for 23 patients with Parkinson's disease with camptocormia, notably including magnetic resonance imaging (MRI) of the brain and spine, electromyographic recordings of the paravertebral muscles and muscle biopsies. RESULTS: Camptocormia occurred in severe Parkinson's disease with axial predominance, motor fluctuations and dysautonomic symptoms. The condition was often associated with spondyloarthritic changes and pain. MRI showed paraspinal muscle signal abnormalities in five patients and fatty involution in seven patients. The seven patients had motor unit reductions on the spinal erector electromyogram. The MRI results for the girdle muscles were normal. Cranial MRI showed signal abnormalities for the basal ganglia in three patients. DISCUSSION: Various mechanisms may contribute to the development of parkinsonian camptocormia: dopaminergic depletion in Parkinson's disease induces functional changes in the organisation of the corticospinal and reticulospinal tracts, where dysfunction could contribute to axial rigidity. Furthermore, rigidity of the spinal flexion muscles could lead to under-use of the spinal extension muscles, which become progressively atrophic. Rigidity may also induce spinal deformations, leading to a neurogenic syndrome via compression of the spinal nerves. CONCLUSION: The screening and early management of camptocormia in Parkinson's disease is likely to be important for preventing axial disorders and spinal deformations.

Correlation between primary flat foot and lower extremity rotational misalignment in adults.

PURPOSE: The goal of this study was to identify rotational abnormalities of the lower limb in adult patients with primary symptomatic flatfoot. MATERIALS AND METHODS: From September 2009 to May 2012, 24 patients (12 women, 12 men; mean age: 40 years) were prospectively included in the study. Each patient underwent radiographs of the flat foot and weight-bearing upright EOS® examination. Three-dimensional reconstructions of the lower extremities were performed with derived measurements (length, hip and knee parameters, rotations). A total of 31 symptomatic primary flat feet (bilateral flat foot, n=7 patients; unilateral flat foot, n=17 patients) were studied and compared to 30 control subjects matched for age and gender. A comparison between the two groups was made with the Student t-test. RESULTS: No significant differences were found between patients and control subjects on the coronal and sagittal planes. Similarly, no significant differences were observed between the 2 groups for rotation of the lower limbs (femoral torsion, tibial torsion, tibiofemoral rotation). CONCLUSION: There are no rotational abnormalities of the lower extremities in adult patients with primary symptomatic flat foot.

[Parkinson's disease, progressive lumbar kyphosis and focal paraspinal myositis]. / Maladie de Parkinson, camptocormie et myosite focale paraspinale.

INTRODUCTION: The camptocormia (bent spine) is characterized by a severe forward flexion of the thoracolumbar spine which disappears in the supine position. Clinical case. We describe a typical case observed in a parkinsonian patient. The MRI, electromyogram and biopsy of the paraspinal muscles revealed a typical myositis pattern. DISCUSSION: This case, the sixth published to our knowledge, confirms that focal myositis is associated with the camptocormia in Parkinson's disease. Typically it is observed in male subjects, appearing 4 to 6 years after the onset of Parkinson's disease, in fluctuating patients treated by an association of L-Dopa and agonist. It appears quickly and becomes the most important symptom. Antiparkinsonian drugs are useless. CONCLUSION: This exceptional picture raises original pathophysiological and therapeutic questions. Systematic studies should be performed in order to detail the pathophysiological link between these 3 entities: Parkinson's disease, focal myositis and camptocormia.

[Usefulness of musculoskeletal ultrasonography in a University Department of Radiology]. / Place de l'échographie parmi les méthodes d'imagerie de l'appareil locomoteur: point de vue d'un chef de service hospitalo-universitaire.

The excellent architectural analysis of muscles, tendons and nerves, the dynamic assessment of theses structures and the easy comparison with the controlateral side explain the usefulness of ultrasonography in the assessment of many musculoskeletal diseases. This technique also represents a pleasant way to learn the musculoskeletal anatomy and allows a better understanding of the physiology and pathophysiology of the musculoskeletal system. Finally, musculoskeletal ultrasonography is more and more used in clinical and fundamental research studies.

Assessment of normal values of fractional anisotropy and mean diffusivity of mobile lumbar spine roots by diffuson tensor MRI: comparison between 1.5 and 3T.

PURPOSE: To assess the normal values of fractional anisotropy (FA) and mean diffusivity (MD) of L4, L5 and S1 nerve roots using diffusion tensor imaging (DTI) in healthy volunteers. MATERIALS AND METHODS: 37 subjects without previous history of lumbalgia or radiculalgia were prospectively examined: 27 at 1.5T and 10 at 3T MRI. The protocol included standard anatomical sequences and a DTI acquisition. Nerve root fibers were semi automatically extracted from DTI tractography. FA and MD values were measured at 4 key portions along each L4, L5 and S1 nerve roots. RESULTS: At 1.5T MRI, FA and MD were 0.221 ± 0.011 and 460.9 ± 35.5 mm2.s-1 respectively; at 3T MRI, FA and MD were 0.216 ± 0.01 and 480.1 ± 36.1 mm2.s-1 respectively, which may be considered as normal values for mobile lumbar spine nerve roots, independently of intersomatic space level (p = 0.06) and nerve root portion (p = 0.08) or magnetic field (p = 0.06). CONCLUSION: Normal FA and MD values can be measured along lumbar mobile spine nerve roots in healthy subjects. These values were not dependent on intersomatic space level, side or anatomical portion of the nerve root or magnetic field.

Magnetic resonance imaging of the forearm: cross-sectional anatomy in a cadaveric model.

RATIONALE AND OBJECTIVES: Compartmental anatomy of the forearm is complex and controversial. The purpose of this investigation was to demonstrate via magnetic resonance the anatomy of forearm compartments and their preferential ways of communication in a human cadaveric model. METHODS: Twelve forearm spaces (11 muscles and one intermuscular) were injected with a solution containing gadopentetate dimeglumine. The extent and distribution of leakage were evaluated on axial fat-suppressed T1-weighted spin-echo images. The findings were related to known descriptions of compartmental anatomy of the forearm. RESULTS: Contrast leakage occurred mostly into the intermuscular space and into the muscles adjacent to the injected muscle. A frank communication within the classically described three forearm compartments (volar, radial, and dorsal) was not present. The interosseous membrane was not an absolute barrier between flexor and extensor compartments. CONCLUSION: The classic description of three forearm compartments may not be sufficient to explain distribution of soft tissue abnormalities.

Comparison of double-contrast CT arthrography image quality with nonionic contrast agents: isotonic dimeric iodixanol 270 mg I/mL and monomeric iohexol 300 mg I/mL.

RATIONALE AND OBJECTIVES: The authors evaluated the image quality on delayed CT arthrography images with the use of the nonionic dimeric contrast agent, iodixanol 270 mg I/mL, compared with iohexol 300 mg I/mL. METHODS: A total of 132 patients with shoulder pain were included in a randomized, parallel, double-blind study. Sixty seven patients received iodixanol and 65 patients received iohexol. Patients underwent two CT-arthrography examinations: the first was performed 20 to 30 minutes after contrast injection and the second, 50 to 70 minutes after contrast injection. Data from 31 patients were excluded from the efficacy analysis. The overall quality of CT arthrography images was graded into four categories: excellent, good, moderate, and bad. RESULTS: The overall quality of delayed CT arthrography images was significantly better in the iodixanol group (P = 0.001, alpha = 0.05). On the first CT examination, image quality was good or excellent in 88% of the cases in the iodixanol group and in 96.1% in the iohexol group. The results on the delayed CT arthrography examination indicated that image quality was good or excellent in 88% of the cases when iodixanol was used and in 63.5% when iohexol was used. CONCLUSIONS: The overall quality of delayed images was significantly better with iodixanol than with iohexol.

Cervical myelopathy secondary to Hunter syndrome in an adult.

We present a case of type II mucopolysaccharidosis in which the diagnosis was delayed until the onset of cervical myelopathy in adulthood. Radiographic features were characteristic, with striking dural thickening shown on CT and MR imaging.

Preoperative percutaneous injection of methyl methacrylate and N-butyl cyanoacrylate in vertebral hemangiomas.

PURPOSE: To investigate the usefulness of preoperative percutaneous injections in vertebral hemangiomas. METHODS: Four patients presented with complicated vertebral hemangioma (spinal cord compression in three cases, intermittent spinal claudiction in one case). A three-part treatment was performed: initially, arterial embolization in three cases; 1 day later, percutaneous injections of methyl methacrylate into the vertebral body to strengthen it and of N-butyl cyanoacrylate into the posterior arch to optimize hemostasis during surgery; finally, the day after percutaneous injections, decompressive laminectomy and epidural hemangioma excision (when present). RESULTS: Laminectomy was performed with minimal blood loss. The epidural component present in three cases was excised without any difficulty. The follow-up (average, 20 months) showed no evidence of vertebral collapse. CONCLUSION: Percutaneous injections of methyl methacrylate and N-butyl cyanoacrylate might be useful before surgery for vertebral hemangiomas.