Study of Thoracic CT in COVID-19: The STOIC Project.

Background There are conflicting data regarding the diagnostic performance of chest CT for COVID-19 pneumonia. Disease extent at CT has been reported to influence prognosis. Purpose To create a large publicly available data set and assess the diagnostic and prognostic value of CT in COVID-19 pneumonia. Materials and Methods This multicenter, observational, retrospective cohort study involved 20 French university hospitals. Eligible patients presented at the emergency departments of the hospitals involved between March 1 and April 30th, 2020, and underwent both thoracic CT and reverse transcription-polymerase chain reaction (RT-PCR) testing for suspected COVID-19 pneumonia. CT images were read blinded to initial reports, RT-PCR, demographic characteristics, clinical symptoms, and outcome. Readers classified CT scans as either positive or negative for COVID-19 based on criteria published by the French Society of Radiology. Multivariable logistic regression was used to develop a model predicting severe outcome (intubation or death) at 1-month follow-up in patients positive for both RT-PCR and CT, using clinical and radiologic features. Results Among 10 930 patients screened for eligibility, 10 735 (median age, 65 years; interquartile range, 51-77 years; 6147 men) were included and 6448 (60%) had a positive RT-PCR result. With RT-PCR as reference, the sensitivity and specificity of CT were 80.2% (95% CI: 79.3, 81.2) and 79.7% (95% CI: 78.5, 80.9), respectively, with strong agreement between junior and senior radiologists (Gwet AC1 coefficient, 0.79). Of all the variables analyzed, the extent of pneumonia at CT (odds ratio, 3.25; 95% CI: 2.71, 3.89) was the best predictor of severe outcome at 1 month. A score based solely on clinical variables predicted a severe outcome with an area under the curve of 0.64 (95% CI: 0.62, 0.66), improving to 0.69 (95% CI: 0.6, 0.71) when it also included the extent of pneumonia and coronary calcium score at CT. Conclusion Using predefined criteria, CT reading is not influenced by reader's experience and helps predict the outcome at 1 month. ClinicalTrials.gov identifier: NCT04355507 Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Rubin in this issue.

Muscular MRI-based algorithm to differentiate inherited myopathies presenting with spinal rigidity.

OBJECTIVES: Inherited myopathies are major causes of muscle atrophy and are often characterized by rigid spine syndrome, a clinical feature designating patients with early spinal contractures. We aim to present a decision algorithm based on muscular whole body magnetic resonance imaging (mWB-MRI) as a unique tool to orientate the diagnosis of each inherited myopathy long before the genetically confirmed diagnosis. METHODS: This multicentre retrospective study enrolled 79 patients from referral centres in France, Brazil and Chile. The patients underwent 1.5-T or 3-T mWB-MRI. The protocol comprised STIR and T1 sequences in axial and coronal planes, from head to toe. All images were analyzed manually by multiple raters. Fatty muscle replacement was evaluated on mWB-MRI using both the Mercuri scale and statistical comparison based on the percentage of affected muscle. RESULTS: Between February 2005 and December 2015, 76 patients with genetically confirmed inherited myopathy were included. They were affected by Pompe disease or harbored mutations in RYR1, Collagen VI, LMNA, SEPN1, LAMA2 and MYH7 genes. Each myopathy had a specific pattern of affected muscles recognizable on mWB-MRI. This allowed us to create a novel decision algorithm for patients with rigid spine syndrome by segregating these signs. This algorithm was validated by five external evaluators on a cohort of seven patients with a diagnostic accuracy of 94.3% compared with the genetic diagnosis. CONCLUSION: We provide a novel decision algorithm based on muscle fat replacement graded on mWB-MRI that allows diagnosis and differentiation of inherited myopathies presenting with spinal rigidity. KEY POINTS: • Inherited myopathies are rare, diagnosis is challenging and genetic tests require specialized centres and often take years. • Inherited myopathies are often characterized by spinal rigidity. • Whole body magnetic resonance imaging is a unique tool to orientate the diagnosis of each inherited myopathy presenting with spinal rigidity. • Each inherited myopathy in this study has a specific pattern of affected muscles that orientate diagnosis. • A novel MRI-based algorithm, usable by every radiologist, can help the early diagnosis of these myopathies.

Pediatric laminopathies: Whole-body magnetic resonance imaging fingerprint and comparison with Sepn1 myopathy.

INTRODUCTION: We sought to define the whole-body MRI (WB-MRI) fingerprint of muscle involvement in pediatric LMNA-related dystrophy (LMNA-RD) and to compare it with SEPN1-related myopathy (SEPN1-RM). METHODS: Signal abnormality and atrophy in 109 muscles were scored by semiquantitative scales in 8 children with LMNA-RD and represented by heatmaps. These features were compared with those from 9 SEPN1-RM patients by random forests. RESULTS: LMNA-RD showed predominant signal abnormalities in erector spinae, serratus anterior, subscapularis, gluteus medius and minimus, vastii, adductor magnus and longus, semimembranosus, medial gastrocnemius, and soleus muscles. Psoas, sternocleidomastoid, gracilis, and sartorius muscles often had normal signal but showed atrophy. Cranial, flexor digitorum longus, and tibialis posterior muscles were spared. According to random forests, atrophied semimembranosus in SEPN1-RM was the most relevant feature to distinguish these patients from LMNA-RD. CONCLUSIONS: A selective pattern in WB-MRI for pediatric LMNA-RD exists and can be differentiated from SEPN1-RM by machine learning. Muscle Nerve 54: 192-202, 2016.

Whole-body muscle magnetic resonance imaging in SEPN1-related myopathy shows a homogeneous and recognizable pattern.

INTRODUCTION: The aim of this study was to delineate the spectrum of muscle involvement in patients with a myopathy due to mutations in SEPN1 (SEPN1-RM). METHODS: Whole-body magnetic resonance imaging (WBMRI) was used in 9 patients using T1-weighted turbo spin-echo (T1-TSE) sequences and short tau inversion recovery (STIR) in 5 patients. RESULTS: Analysis of signal and volume abnormalities by T1-TSE sequences in 109 muscles showed a homogeneous pattern characterized by a recognizable combination of atrophy and signal abnormalities in selected muscles of the neck, trunk, pelvic girdle, and lower limbs. Severe wasting of sternocleidomastoid muscle and atrophy of semimembranosus were detected. Selective paraspinal, gluteus maximus, and thigh muscle involvement was also observed. The lower leg was less constantly affected. CONCLUSIONS: WBMRI scoring of altered signal and atrophy in muscle can be represented by heatmaps and is associated with a homogeneous, recognizable pattern in SEPN1-RM, distinct from other genetic muscle diseases.

Whole-body muscle MRI to detect myopathies in non-extrapyramidal bent spine syndrome.

OBJECTIVE: Bent spine syndrome (BSS), defined as an abnormal forward flexion of the trunk resolving in supine position, is usually related to parkinsonism, but can also be encountered in myopathies. This study evaluates whole-body muscle MRI (WB-mMRI) as a tool for detecting underlying myopathy in non-extrapyramidal BSS. MATERIALS AND METHODS: Forty-three patients (90 % women; 53-86 years old) with a non-extrapyramidal BSS were prospectively included. All underwent a 1.5-T WB-mMRI and a nerve conduction study. Muscle biopsy was performed if a myopathy could not be eliminated based on clinical examination and all tests. Systematic MRI interpretation focused on peripheral and axial muscle injury; spinal posture and incidental findings were also reported. RESULTS: WB-mMRI was completed for all patients, with 13 muscle biopsies ultimately needed and myopathy revealed as the final etiological diagnosis in five cases (12 %). All biopsy-proven myopathies were detected by the WB-mMRI. Relevant incidental MRI findings were made in seven patients. CONCLUSIONS: This study supports WB-mMRI as a sensitive and feasible tool for detecting myopathy in BSS patients. Associated with electroneuromyography, it can better indicate when a muscle biopsy is needed and guide it when required. Rigorous radiological interpretation is mandatory, so as not to miss incidental findings of clinical consequence.

Asbestos-related diseases in automobile mechanics.

PURPOSE: Automobile mechanics have been exposed to asbestos in the past, mainly due to the presence of chrysotile asbestos in brakes and clutches. Despite the large number of automobile mechanics, little is known about the non-malignant respiratory diseases observed in this population. The aim of this retrospective multicenter study was to analyse the frequency of pleural and parenchymal abnormalities on high-resolution computed tomography (HRCT) in a population of automobile mechanics. METHODS: The study population consisted of 103 automobile mechanics with no other source of occupational exposure to asbestos, referred to three occupational health departments in the Paris area for systematic screening of asbestos-related diseases. All subjects were examined by HRCT and all images were reviewed separately by two independent readers; who in the case of disagreement discussed until they reached agreement. Multiple logistic regression models were constructed to investigate factors associated with pleural plaques. RESULTS: Pleural plaques were observed in five cases (4.9%) and interstitial abnormalities consistent with asbestosis were observed in one case. After adjustment for age, smoking status, and a history of non-asbestos-related respiratory diseases, multiple logistic regression models showed a significant association between the duration of exposure to asbestos and pleural plaques. CONCLUSIONS: The asbestos exposure experienced by automobile mechanics may lead to pleural plaques. The low prevalence of non-malignant asbestos-related diseases, using a very sensitive diagnostic tool, is in favor of a low cumulative exposure to asbestos in this population of workers.

Early mechanical ventilation in patients with Guillain-Barré syndrome at high risk of respiratory failure: a randomized trial.

INTRODUCTION: About 30% of patients with Guillain-Barré syndrome become ventilator dependent, of whom roughly 75% develop pneumonia. This trial aimed at assessing the impact of early mechanical ventilation (EMV) on pneumonia occurrence in GBS patients. We hypothesize that EMV will reduce the incidence of pneumonia. METHODS: This was a single centre, open-label, randomized controlled trial performed on two parallel groups. 50 intensive care unit adults admitted for Guillain-Barré syndrome and at risk for acute respiratory failure. Patients were randomized to early mechanical ventilation via face-mask or endotracheal intubation owing to the presence or absence of impaired swallowing (experimental arm), or to conventional care (control arm). The primary outcome was the incidence of pneumonia up to intensive care unit discharge (or 90 days, pending of which occurred first). FINDINGS: Twenty-five patients were randomized in each group. There was no significant difference between groups for the incidence of pneumonia (10/25 (40%) vs 9/25 (36%), P = 1). There was no significant difference between groups for the time to onset of pneumonia (P = 0.50, Gray test). During follow-up, there were 16/25 (64%) mechanically ventilated patients in the control group, and 25/25 (100%) in the experimental arm (P < 000·1). The time on ventilator was non-significantly shorter in the experimental arm (14 [7; 29] versus 21.5 [17.3; 35.5], P = 0.10). There were no significant differences between groups for length of hospital stay, neurological scores, the proportion of patients who needed tracheostomy, in-hospital death, or any serious adverse events. CONCLUSIONS: In the present study including adults with Guillain-Barré syndrome at high risk of respiratory failure, we did not observe a prevention of pneumonia with early mechanical ventilation. TRIAL REGISTRATION: ClinicalTrials.gov under the number NCT00167622. Registered 9 September 2005, https://clinicaltrials.gov/ct2/show/NCT00167622?cond=Guillain-Barre+Syndrome&cntry=FR&draw=2&rank=1.

CT and MRI of spinal neuroarthropathy.

OBJECTIVE: The objective of this article is to describe the different stages of spinal neuroarthropathy as assessed by CT and MRI and to discuss their contribution to the management of affected patients. CONCLUSION: Early-stage findings consisted of inflammatory changes involving adjacent vertebral endplates and mimicking degenerative disk disease with inflammation. Subsequently, progression of the lesions led to complete destruction of the intervertebral joint. Knowledge of the initial features of spinal neuroarthropathy may allow earlier treatment, which may improve outcomes.

Diaphragm sniff ultrasound: Normal values, relationship with sniff nasal pressure and accuracy for predicting respiratory involvement in patients with neuromuscular disorders.

BACKGROUND: In patients with neuromuscular disorders, assessment of respiratory function relies on forced vital capacity (FVC) measurements. Providing complementary respiratory outcomes may be useful for clinical trials. Diaphragm sniff ultrasound (US) is a noninvasive technique that can assess diaphragm function that may be affected in patients with neuromuscular disorders. PURPOSE: We aimed to provide normal values of sniff diaphragm ultrasound, to assess the relationship between sniff diaphragm US, vital capacity (VC) and sniff nasal pressure. Additionally, we aimed to evaluate the diagnostic accuracy of sniff diaphragm US for predicting restrictive pulmonary insufficiency. MATERIALS AND METHODS: We included patients with neuromuscular disorders that had been tested with a sniff diaphragm US and functional respiratory tests. Healthy subjects were also included to obtain normal diaphragm sniff ultrasound. We performed diaphragm tissue Doppler imaging (TDI) and time movement (TM) diaphragm echography combined with sniff maneuver. RESULTS: A total of 89 patients with neuromuscular diseases and 27 healthy subjects were included in our study. In patients, the median age was 32 years [25; 50] and the median FVC was 34% of predicted [18; 55]. Sniff diaphragm motion using TM ultrasound was significantly associated with sniff nasal pressure, both for the right hemidiaphragm (r = 0.6 p <0.0001) and the left hemidiaphragm (r = 0.63 p = 0.0008). Right sniff peak TDI velocity was also significantly associated with FVC (r = 0.72, p<0.0001) and with sniff nasal pressure (r = 0.66 p<0.0001). Sniff diaphragm ultrasound using either TM mode or TDI displayed significant accuracy for predicting FVC<60% with an area under curve (AUC) reaching 0.93 (p<0.0001) for the right sniff diaphragm ultrasound in TM mode and 0.86 (p<0.001) for right peak diaphragm TDI velocity. CONCLUSION: Sniff diaphragm TM and TDI measures were significantly associated with sniff nasal pressure. Sniff diaphragm TM and TDI had a high level of accuracy to reveal respiratory involvement in patients with neuromuscular disorders. This technique is useful to assess and follow up diaphragm function in patients with neuromuscular disorders. It may be used as a respiratory outcome for clinical trials.

Human muscle-derived CLEC14A-positive cells regenerate muscle independent of PAX7.

Skeletal muscle stem cells, called satellite cells and defined by the transcription factor PAX7, are responsible for postnatal muscle growth, homeostasis and regeneration. Attempts to utilize the regenerative potential of muscle stem cells for therapeutic purposes so far failed. We previously established the existence of human PAX7-positive cell colonies with high regenerative potential. We now identified PAX7-negative human muscle-derived cell colonies also positive for the myogenic markers desmin and MYF5. These include cells from a patient with a homozygous PAX7 c.86-1G > A mutation (PAX7null). Single cell and bulk transcriptome analysis show high intra- and inter-donor heterogeneity and reveal the endothelial cell marker CLEC14A to be highly expressed in PAX7null cells. All PAX7-negative cell populations, including PAX7null, form myofibers after transplantation into mice, and regenerate muscle after reinjury. Transplanted PAX7neg cells repopulate the satellite cell niche where they re-express PAX7, or, strikingly, CLEC14A. In conclusion, transplanted human cells do not depend on PAX7 for muscle regeneration.

Echographic Assessment of Diaphragmatic Function in Duchenne Muscular Dystrophy from Childhood to Adulthood.

BACKGROUND: Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic muscle disorder. Respiratory muscle function is classically affected in this disease. Ultrasound recently emerged as a non-invasive tool to assess diaphragm function. However, there are only a few studies using diaphragm ultrasound (US) in DMD. PURPOSE: We aimed to assess diaphragm ultrasound patterns in DMD, their relationship with age and their association with home mechanical ventilation (HMV). METHODS: We included DMD patients followed at Raymond Poincaré Hospital who benefited from diaphragm ultrasound and pulmonary function tests. RESULTS: There were 110 DMD patients and 17 male sex-matched healthy subjects included. In all, 94% of patients were permanent wheelchair users. Median body mass index (BMI) was 18 kg/m2. DMD patients disclosed a reduced forced vital capacity (VC) (12% of predicted value), and 78% of patients were on HMV. In patients, right and left diaphragmatic motions on deep inspiration were reduced and end expiratory diaphragm thickness was borderline normal. In patients, right and left diaphragmatic thickening fractions (TF) were reduced 12.7% and 15.5%, respectively. Age and end expiratory thickness were significantly inversely associated (p = 0.005 for the right diaphragm, p = 0.018 for the left diaphragm). Diaphragm TF was significantly inversely associated with age (p = 0.001 for the right side, p < 0.0001 for the left side). Right and left inspiratory diaphragm motions were significantly inversely associated with age (p < 0.0001). CONCLUSION: This study describes the severity of diaphragm dysfunction in patients with DMD. Diaphragm US may be a non-invasive outcome measure for DMD.

Diaphragm: Pathophysiology and Ultrasound Imaging in Neuromuscular Disorders.

Respiratory muscles are classically involved in neuromuscular disorders, leading to a restrictive respiratory pattern. The diaphragm is the main respiratory muscle involved during inspiration. Ultrasound imaging is a noninvasive, radiation-free, accurate and safe technique allowing assessment of diaphragm anatomy and function. The authors review the pathophysiology of diaphragm in neuromuscular disorders, the methodology and indications of diaphragm ultrasound imaging as well as possible pitfalls in the interpretation of results.

Actinomyces graevenitzii pulmonary abscess mimicking tuberculosis in a healthy young man.

Pulmonary actinomycosis is a rare disease that is often misdiagnosed as tuberculosis or lung cancer. Actinomyces graevenitzii is a relatively new recognized Actinomyces species isolated from various clinical samples. The authors report a case of pulmonary actinomycosis caused by A graevenitzii. A computed tomography examination revealed an excavated consolidation in the middle right lobe of a previously healthy young man who presented with a long history of moderate cough. Cultures of the bronchoalveolar lavage fluid confirmed the diagnosis of pulmonary abscess caused by A gravenitzii. At the three-month follow-up consultation and, after six weeks of high-dose amoxicillin, the pulmonary lesion had completely disappeared.

Whole-body muscle MRI in 20 patients suffering from late onset Pompe disease: Involvement patterns.

To describe muscle involvement on whole-body MRI scans in adult patients at different stages of late-onset Pompe disease. Twenty patients aged 37 to 75 were examined. Five were bedridden and required ventilatory support. Axial and coronal T1 turbo-spin-echo sequences were performed on 1.5T or 3T systems. MRI was scored for 47 muscles using Mercuri's classification. Whole-body scans were obtained with a mean in-room time of 29 min. Muscle changes consisted of internal bright signals of fatty replacement without severe retraction of the muscles' corpus. Findings were consistent with previous descriptions of spine extensors and pelvic girdle, but also provided new information on recurrent muscle changes particularly in the tongue and subscapularis muscle. Moreover thigh involvement was more heterogeneous than previously described, in terms of distribution across muscles as well as with respect to the overall clinical presentation. Whole-body MRI provides a very evocative description of muscle involvement in Pompe disease in adults.

Occupational paraffin-induced pulmonary fibrosis: a 25-year follow-up.

Exogenous lipid pneumonia can exceptionally be caused by occupational exposure to paraffin. The authors report a case of severe interstitial pulmonary disease induced by occupational exposure to paraffin, leading to delayed fibrosis over a 25-year follow-up, despite cessation of exposure.

Osteoporotic vertebral collapse: percutaneous vertebroplasty and local kyphosis correction.

Forty-six cases of osteoporotic vertebral collapse (27 thoracic, 19 lumbar) were treated by means of percutaneous vertebroplasty in a hyperlordosis position. Institutional review board approval and informed consent were obtained. Kyphosis reducibility was preprocedurally estimated from the angular difference between neutral and hyperlordosis positions. Effective reduction was the angular difference in neutral positions before and after vertebroplasty. Reduction (< or =14 degrees ; mean, 6.43 degrees) was obtained in cases with estimated reducibility greater than 5 degrees (31 cases, 67%), which is a 34% (6.5 degrees of 19.1 degrees ) mean reduction. A significantly greater level of kyphosis reduction was observed in cases with intravertebral clefts (20 cases, 43%) at hyperlordosis than in those without (7.2 degrees vs 4.9 degrees ; P < .01). Vertebroplasty may reduce kyphosis due to localized collapsed vertebrae; intravertebral mobility and cleft suggest this possibility.

Anterior cruciate ligament reconstruction with bioabsorbable polyglycolic acid interference screws: MR imaging follow-up.

PURPOSE: To examine at magnetic resonance (MR) imaging the degradation of an interference screw made of polyglycolic acid (67.5%) and trimethylene carbonate (32.5%) and compare the MR findings with the clinical evaluation results. MATERIALS AND METHODS: Clinical and MR imaging studies were performed concomitantly 6 months (in 20 patients), 1 year (in 10 patients), and 2 years (in eight patients) after surgery. Screw resorption rate, tibial tunnel appearance and contents, epiphyseal reaction, reconstructed ligament appearance, bone plug healing, joint effusion, and synovitis were evaluated. RESULTS: The screw was observed to be partially resorbed (by approximately one-third) at 6 months and totally resorbed at 1 year. Enhancement of the tunnel content, which can be linked to bone healing and screw replacement, was seen without a surrounding inflammatory reaction. Bone tunnel enlargement was observed and remained stable over time; this phenomenon has often been reported with metallic or polylactic acid interference screws and could be due to the position of the screw within the tunnel. The tissue that was seen at MR imaging to be replacing the screw was either fibrous or fatty and fibrous but never bone. CONCLUSION: Resorption of the screw does not appear to be related to clinical results.