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.

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.

Abnormal proliferation of intraergastoplasmic microfilaments in myelinated schwann cells: ultrastructural study of two cases.

We report the ultrastructural findings in superficial peroneal nerve biopsies in two patients, one with idiopathic sensory neuropathy and the other with the Guillain-Barré syndrome and Hodgkin's disease. In addition to demyelination, there was an intense proliferation of microfilaments within numerous vesicles of the endoplasmic reticulum of a great number of myelinated Schwann cells. This abnormality does not appear to have been previously reported in the literature. The mechanisms responsible for this finding are unknown.

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.

Primary systemic amyloidosis. An electron microscopic study of the vitreous.

We performed an electron microscopic study of the vitreous of a patient with primary systemic amyloidosis. Amyloid deposits were found using the technique previously used to differentiate amyloidosis in urinary sediments.

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.

[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.

[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).

[Ultrastructural and experimental study of the ocular toxicity of antibiotics and antifungals on the corneal endothelium (author's transl)]. / Etude expérimentale en ultrastructure de la toxicité des antibiotiques ou des antifongiques sur l'endothélium cornéen.

The authors report an experimental study on the ocular toxicity of some antibiotics (ampicillin, gentamicin, cephalotin sodic, tobramycin) and some antifungals (amphotericin B, flucytosin). For this study they used both the transmission electron microscope and the scanning microscope. The most important modifications of the corneal endothelium were observed with amphotericin b, flucytosin. cephalotin sodic. The toxicity seems to be lower with gentamicin and with tobramycin. Ampicillin produced few visible changes. This study was realized with the aim to determine the quantities of antimicrobials that could be injected in the human eye without corneal lesions in the treatment of endophthalmitis (bacterial or fungal).

[Ultrastructural aspect of the different levels of the lacrimal system (author's transl)]. / Les cellules ciliées du système lacrymal. Ultrastructure comparée de la muqueuse lacrymale.

Using the transmission electron microscope and the scanning electron microscope, we have found a different ultrastructure at the different levels of the lacrimal system: 1) tarsal conjonctiva: numerous microvilli on a relief of small valleys; 2) lacrimal punctum: the surface of the cell is flat with sparse microvillosti, sparse cilia and strong intercellular junction; 3) external part of the canaliculus: pavement epithelium with numerous microvillositi and pinocytosis, absence of cilia; 4) internal part of the canaliculus: the microvillositi are very small or absent; 5) lacrimal sac: the cilia are arranged by tufts scattered on this malpighian epithelium; 6) nasolacrimal duct: the cilia are numerous; 7) in the nose the cilia are extremely numerous.

[Conjunctival biopsies in diffuse amyloid (author's transl)]. / Résultats de la biopsie conjonctivale dans l'amylose généralisée. Quatre observations.

Amyloid well known as a homogeneous eosinophilic material deposited in various body tissues. Conjunctival biopsies in four patients distributed among the different classical type of diffuse amyloidosis demonstrate the diagnostic value of this simple procedure. In all cases, by optic microscopy amyloid deposits were seen in the subepithelial connective tissue of the conjunctiva. Electron microscopy showed the characteristic fibrillar material of amyloid, with its fiber diameter of 9 to 12 nm in all cases. Since it is a totally harmless procedure, it seems obvious that each time systemic amyloidosis is suspected, conjunctival biopsy must be done first.

[Skin fibrosis in hyperthyroidism treated by sotalol and radioactive iodine (author's transl)]. / Fibrose cutanée chez des hyperthyroïdiens traités par l'association sotalol-iode radioactif.

The authors present detailed data about skin fibrosis appearing in hyperthyroidism treated by Sotalol and radioactive iodine. Cutaneous thickening is discovered quite rapidly when the patient is monitored daily (as in case 4). It is asymptomatic and no other features of scleroderma are found. Regression occurs within 4-10 months. Histologically, fibrosis is located in the entire dermis. Dermal appendages are normal and no inflammatory changes occur. No anomalies of collagen structure and fibroblasts have been observed ultrastructurally. Immunological studies (direct immunofluorescence of the skin, lymphocyte transformation and leucocyte migration tests with Sotalol) were normal. The mechanism is unknown, but an immunological or a toxic one is excluded; however a pharmacological action is possible. The role of other betablockers must be assessed by a randomised study.

Cryoglobulinemic neuropathy: ultrastructural study of the nerve capillaries.

The authors report here the case of a female patient who developed symmetrical polyneuropathy of the lower limbs a few months after she was found to have a myeloma with cryoglobulinemia. In musculocutaneous nerve biopsy material from this patient, electron microscopy showed pathological changes in the nervous tissue together with axonal degeneration and demyelination. But the most striking finding was the presence in the endoneurial space, of numerous masses made up of closely packed tubular structures. These masses occurred also in the walls and even in the lumen of all the vasa nervorum. Their morphologic features and dimensions were identical to cryoprecipitate which the authors extracted from the serum and which they examined with electron microscope.