Artificial intelligence solution to classify pulmonary nodules on CT.

PURPOSE: The purpose of this study was to create an algorithm to detect and classify pulmonary nodules in two categories based on their volume greater than 100 mm3 or not, using machine learning and deep learning techniques. MATERIALS AND METHOD: The dataset used to train the model was provided by the organization team of the SFR (French Radiological Society) Data Challenge 2019. An asynchronous and parallel 3-stages pipeline was developed to process all the data (a data "pre-processing" stage; a "nodule detection" stage; a "classifier" stage). Lung segmentation was achieved using 3D U-NET algorithm; nodule detection was done using 3D Retina-UNET and classifier stage with a support vector machine algorithm on selected features. Performances were assessed using area under receiver operating characteristics curve (AUROC). RESULTS: The pipeline showed good performance for pathological nodule detection and patient diagnosis. With the preparation dataset, an AUROC of 0.9058 (95% confidence interval [CI]: 0.8746-0.9362) was obtained, 87% yielding accuracy (95% CI: 84.83%-91.03%) for the "nodule detection" stage, corresponding to 86% specificity (95% CI: 82%-92%) and 89% sensitivity (95% CI: 84.83%-91.03%). CONCLUSION: A fully functional pipeline using 3D U-NET, 3D Retina-UNET and classifier stage with a support vector machine algorithm was developed, resulting in high capabilities for pulmonary nodule classification.

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.

Nodular reverse halo sign in active pulmonary tuberculosis: A rare CT feature?

PURPOSE: The purpose of this study was to investigate the prevalence of the nodular reverse halo sign (NRHS) in chest computed tomography (CT) in patients with active pulmonary tuberculosis. MATERIALS AND METHODS: From March 2018 to March 2019, 29 consecutive patients with a culture-confirmed active pulmonary tuberculosis and who underwent chest CT examination during hospital-admission were retrospectively included in the study. There were 24 men and 5 women with a mean age of 40.9±16.7 (SD) years (range: 18-80years). Chest CT examinations of included patients were evaluated for the presence of NRHS and other tuberculosis-related CT signs. RESULTS: CT revealed the NRHS in 5 patients (5/29; 17%). The other CT signs of tuberculosis included consolidations in 18 patients (18/29; 62%), tree-in-bud pattern in 14 patients (14/29; 48%), cavitation in 12 patients (12/29; 41%), sparse nodules in 10 patients (10/29; 34%), and pleural effusion in 8 patients (8/29; 28%). CONCLUSION: CT shows NRHS in 17% of patients with active pulmonary tuberculosis, indicating that the sign is not as rare as previously thought in patients with this condition.

[Clear cell tumor of the lung (sugar tumour). Study of a case]. / Tumeur à cellules claires du poumon ("sugar tumour"). Etude d'un cas.

A case of benign clear cell tumor ("sugar tumor") is reported. Light microscopy showed a proliferation of clear cells with a rich blood supply and endocrinoid pattern. Ultrastructurally, cells were loaded with glycogen both free and membrane-bound. The cellular origin of the benign clear cell tumor of the lung is still uncertain.

[Toxoplasma gondii: ultrastructural study of cystic formations observed in human fibroblast culture]. / Toxoplasma gondii: étude ultrastructurale des formations kystiques observées en culture de fibroblastes humains.

A strain of Toxoplasma gondii, non pathogenic to mice (Prugniaud strain) produced cyst-like stages when inoculated in human fibroblast culture. An ultrastructural study was performed in order to compare these cyst-like forms to brain cysts of the same strain and to intracellular clusters of tachyzoites observed in mice TG 180 sarcoma cells. Electron microscopy confirmed the similarities between brain cysts and cysts obtained in vitro.

Effects of glycerol injection into rat sciatic nerve.

In recent years, injection of pure glycerol into the trigeminal cistern has been used for the treatment of trigeminal neuralgia. The mechanism of action of this therapy remains unclear. Using both light and electron microscopy, we investigated the effects of microinjections of sterile, pure glycerol into the endoneurium of the sciatic nerve of the rat. We observed total destruction of both myelinated and unmyelinated fibers. In nearly all animals, signs of automutilation were observed in the paralyzed limb. Histological evidence of nerve degeneration appeared soon after injection, with intense proliferation of perineurial cells that eventually divided the endoneurium into numerous microcompartments.

Acute pure sensory paraneoplastic neuropathy with perivascular endoneurial inflammation: ultrastructural study of capillary walls.

We studied a patient with epidermoid carcinoma of the lung (treated surgically 1 year earlier) and an acute symmetric pure sensory neuropathy that regressed almost completely within 1 month. Superficial peroneal nerve biopsy 15 days after onset showed evidence of demyelination with perivascular endoneurial inflammation. On ultrastructural examination, lymphocytes were seen passing through endothelial cells of endoneurial capillaries.

Case of dementia and myoclonia in an adult associated with anomalies in polyunsaturated fatty acids in leukocytes and peripheral nerve. An ultrastructural study of peripheral nerve.

We report a case of a 66-year-old patient presenting with abnormal movements and associated dementia. Death occurred 4 years after the onset of symptoms. In spite of the lack of autopsy results, the picture was one of late onset neuronal ceroid lipofuscinosis (Kufs' disease). Ultrastructural study of a peripheral nerve biopsy sample indicated a process of demyelination associated with unusual inclusions in Schwann cell cytoplasm. Biochemical analysis of the same sample and leukocytes showed considerable alterations in polyunsaturated fatty acid levels. These findings are discussed in the light of work on cases of infantile neuronal ceroid lipofuscinosis.

[Morphological effects of microinjections of Lewis rat serum into nerves of Lewis rats]. / Effets morphologiques de microinjections de sérum de rat Lewis dans le nerf de rat Lewis.

Recent reports have shown that intraneural injections of sera from patients with Guillain-Barré syndrome have demyelinating effects on rat peripheral nerve. Some authors have proposed that this could merely result from immune phenomena due to species differences. In this study we injected normal human sera and sera from normal Lewis rats into nerves of Lewis rats. We consider that the small lesions observed were due more to the injection procedure itself than to effects of the sera.

Familial Creutzfeldt-Jakob disease with extensive degeneration of white matter. Ultrastructure of peripheral nerve.

A case of Creutzfeldt-Jakob disease (CJD) in a 52-year-old man is described. At post mortem, extensive involvement of white matter was seen. A few similar cases have been reported mainly by Japanese authors. Our patients belonged to a French family in which 14 cases of CJD over three generations have been recorded. One of the patient's first cousins also had extensive white matter involvement. This is an unusual panencephalopathic form of CJD. The causes of the involvement of white matter are unknown. There was no clinical evidence of neuropathy but an electron-microscopic study of biopsied superficial peroneal nerve showed it to be present. Study of peripheral nerves is suggested for all patients with CJD.

Nonviral intranuclear inclusions in a nerve biopsy: an ultrastructural study.

During the ultrastructural study of a nerve biopsy from a diabetic patient suffering from chronic polyradiculoneuritis, we observed that a significant number of endoneural fibroblasts had abnormal nuclei. They contained a round, centrally located inclusion consisting of numerous irregularly arranged filaments approximately 15 nm in diameter. No such lesion in peripheral nerve has previously been reported. Interpretation of these abnormalities is difficult.

[Embryologic study of the lacrimal ducts in man. Apropos of 10 cases]. / Etude embryologique des voies lacrymales chez l'homme. A propos de dix cas.

The embryology of the human lacrimal system is not clearly defined in the literature and two hypotheses exist: the first suggests that the origin of the lacrimal system is from an ectodermal fold forming a sulcus of the naso-optic fissure. The second, with few defenders, describes the first rod of cells as meeting a second one which appears to emerge from the primitive nasal cavity. A study of ten human embryos, aged from 14 to 25 weeks and with a length of 12 to 33 cm, examined by histologic sections of 10 microns, revealed no lacrimal origin in the primitive nasal cavity near the inferior meatus. A further interesting point was that in three of the four embryos aged four months the lacrimal point was opened. Most authors, however, found the lacrimal sac and the nasolacrimal duct to be dilated, especially in one case where the inferior part of the nasolacrimal duct at the ostium below the inferior turbinate and meatus was widely dilated. In all the cases, the lower end of the duct was separated from the nasal cavity by a fine membrane in opposition with the nasal mucosa.

[Melanocytoma of the iris and ciliary body and multiple pigmented tumors ultrastructural study]. / Mélanocytome de l'iris, du corps ciliaire et tumeurs pigmentées multiples. Etude ultrastructurale.

The authors report an ultrastructural study of a melanocytoma of the iris and the ciliary body which has been excised by an iridocyclectomy because of the extension into the angle and of the rapid growth. In this tumor we have found a great number of melanocytes, some melanophages and few collagen fibers. The melanocytes include a lot of mature melanosomes. The melanophages are characterized by the compound melanosomes and the lysosomial bodies. In both cells the number of melanosomes was high, filling nearly all the cytoplasm. The evolution for the eye after the operation was good but the patient died two years later for an unknown reason. This iris tumor was associated with two others pigmented tumors: a benign cystic nevus of the caroncula and a choroidal nevus. The ultrastructural study of the conjunctival nevus shows vacuolated cells under the basement membrane. These cells are organised around large surface of mucus. These epithelial inclusion cells look like pseudocyst formation. The originality of this work is that few melanocytoma of the iris has been studied by transmission electron microscopy and the association with two others benign nevi (caroncula, choroïd).