Five simultaneous artificial intelligence data challenges on ultrasound, CT, and MRI.

PURPOSE: The goal of this data challenge was to create a structured dynamic with the following objectives: (1) teach radiologists the new rules of General Data Protection Regulation (GDPR), while building a large multicentric prospective database of ultrasound, computed tomography (CT) and MRI patient images; (2) build a network including radiologists, researchers, start-ups, large companies, and students from engineering schools, and; (3) provide all French stakeholders working together during 5 data challenges with a secured framework, offering a realistic picture of the benefits and concerns in October 2018. MATERIALS AND METHODS: Relevant clinical questions were chosen by the Société Francaise de Radiologie. The challenge was designed to respect all French ethical and data protection constraints. Multidisciplinary teams with at least one radiologist, one engineering student, and a company and/or research lab were gathered using different networks, and clinical databases were created accordingly. RESULTS: Five challenges were launched: detection of meniscal tears on MRI, segmentation of renal cortex on CT, detection and characterization of liver lesions on ultrasound, detection of breast lesions on MRI, and characterization of thyroid cartilage lesions on CT. A total of 5,170 images within 4 months were provided for the challenge by 46 radiology services. Twenty-six multidisciplinary teams with 181 contestants worked for one month on the challenges. Three challenges, meniscal tears, renal cortex, and liver lesions, resulted in an accuracy>90%. The fourth challenge (breast) reached 82% and the lastone (thyroid) 70%. CONCLUSION: Theses five challenges were able to gather a large community of radiologists, engineers, researchers, and companies in a very short period of time. The accurate results of three of the five modalities suggest that artificial intelligence is a promising tool in these radiology modalities.

Local extension staging of sinonasal tumours: retrospective comparison between CT/MRI assessment and pathological findings.

OBJECTIVES: To assess the reliability of clinical staging with CT and MRI in sinonasal cancers. METHODS: We conducted a retrospective review of patients who underwent surgery for a sinonasal cancer. The 7th edition of the TNM classification was used to establish tumour staging. Standardised preoperative CT/MRI staging was compared with the pathological staging based on specimens obtained during surgery from each subsite within and around the tumour. RESULTS: We analysed data from 68 patients between January 2010 and December 2014. A comparison of cT and pT stages was established for 49 naso-ethmoidal and 16 maxillary tumours. Clinical staging for naso-ethmoidal cT1 and maxillary cT2 was consistent with pathological results. Clinical staging for naso-ethmoidal cT2, cT3 and cT4b was overstated in comparison with pT findings. The positive predictive value of imaging was <65% for the lamina papyracea, the cribriform plate, the dura, and the frontal and sphenoid sinuses. Sensitivity was over 75% for each anatomical site except for the cribriform plate (73.3%) and the sphenoid sinus (57.2%). CONCLUSION: Systematic pathologic analysis of the anatomical areas around the sinonasal cancer has to be applied in further studies to improve our therapeutic management. CT/MRI mapping cannot replace accurate assessment of tumour extension during surgery.

How to perform 3D reconstruction of skull base tumours.

The surgical management of skull base lesions is difficult due to the complex anatomy of the region and the intimate relations between the lesion and adjacent nerves and vessels. Minimally invasive approaches are increasingly used in skull base surgery to ensure an optimal functional prognosis. Three-dimensional (3D) computed tomography (CT) reconstruction facilitates surgical planning by visualizing the anatomical relations of the lesions in all planes (arteries, veins, nerves, inner ear) and simulation of the surgical approach in the operating position. Helical CT angiography is performed with optimal timing of the injection in terms of tumour and vessel contrast enhancement. 3D definition of each structure is based on colour coding by automatic thresholding (bone, vessels) or manual segmentation on each slice (tumour, nerves, inner ear). Imaging is generally presented in 3 dimensions (superior, coronal, sagittal) with simulation of the surgical procedure (5 to 6 reconstructions in the operating position at different depths).

Initial staging of squamous cell carcinoma of the oral cavity, larynx and pharynx (excluding nasopharynx). Part 2: Remote extension assessment and exploration for secondary synchronous locations outside of the upper aerodigestive tract. 2012 SFORL guidelines.

OBJECTIVES: This report presents the French Society of ORL (SFORL) guidelines for exploration for remote metastasis and synchronous second cancer in initial staging of head and neck squamous cell carcinoma. MATERIALS AND METHODS: An exhaustive literature review was analyzed by a multidisciplinary work-group. RESULTS: The thorax is the most frequent location of remote metastases and synchronous second cancer outside of the upper aerodigestive tract. Thoracic CT is recommended as first-line examination in all cases (grade B). 18-FDG PET/CT is recommended when the thoracic CT image is doubtful or in case of high metastatic risk (grade B), for the detection of non-pulmonary remote metastasis. Esophageal exploration is recommended in case of significant risk of synchronous esophageal cancer (hypopharyngeal or oropharyngeal tumor, chronic alcohol intoxication) (grade B). The reference examination is flexible endoscopy of the upper digestive tract (grade B). CONCLUSION: The present grade B recommendations rationalize the roles of the various first-line radiological and endoscopic examinations for remote metastasis and synchronous second cancer, so as to limit the number of examinations performed, thereby reducing the time needed for initial staging.

Initial staging of squamous cell carcinoma of the oral cavity, larynx and pharynx (excluding nasopharynx). Part I: Locoregional extension assessment: 2012 SFORL guidelines.

OBJECTIVES: To set out good practice guidelines for locoregional extension assessment of squamous cell carcinoma of the head and neck (excluding nasopharynx, nasal cavities and sinuses). MATERIALS AND METHODS: A critical multidisciplinary review of the literature on locoregional extension assessment of squamous cell carcinoma of the head and neck was conducted, applying levels of evidence in line with the French health authority's (HAS) literature analysis guide of January 2000. CONCLUSION: Based on the levels of evidence of the selected articles and on work-group consensus, graded guidelines are set out for clinical, endoscopic and imaging locoregional extension assessment of head and neck cancer.

Cochlear implant with a non-removable magnet: preliminary research at 3-T MRI.

OBJECTIVE: To perform preliminary tests in vitro and with healthy volunteers to determine the 3-T MRI compatibility of a cochlear implant with a non-removable magnet. METHODS: In the in vitro phase, we tested six implants for temperature changes and internal malfunctioning. We measured the demagnetisation of 65 internal magnets with different tilt angles between the implant's magnetic field (bi) and the main magnetic field (b0). In the in vivo phase, we tested 28 operational implants attached to the scalps of volunteers with the head in three different positions. RESULTS: The study did not find significant temperature changes or electronic malfunction in the implants tested in vitro. We found considerable demagnetisation of the cochlear implant magnets in the in vitro and in vivo testing influenced by the position of the magnet in the main magnetic field. We found that if the bi/b0 angle is <90°, there is no demagnetisation; if the bi/b0 angle is >90°, there is demagnetisation in almost 60 % of the cases. When the angle is around 90°, the risk of demagnetisation is low (6.6 %). CONCLUSION: The preliminary results on cochlear implants with non-removable magnets indicate the need to maintain the contraindication of passage through 3-T MRI. KEY POINTS: • Magnetic resonance imaging can affect cochlear implants and vice versa. • Demagnetisation of cochlear implant correlates with the angle between bi and b0. • The position of the head in the MRI influences the demagnetisation. • Three-Tesla MRI for cochlear implants is still contraindicated. • However some future solutions are discussed.

Imaging of non-operated cholesteatoma: clinical practice guidelines.

Middle ear cholesteatoma is an aggressive form of chronic otitis media requiring surgical therapy. The surgical strategy depends on the location of the lesion, its extensions to the middle ear and mastoid, the anatomical conformation of the tympanomastoid cavities and the health status of the patient (as well as his or her interest in aquatic leisure activities). For several years, imaging of the ear has been a routine test in the preoperative work-up of the disease. National guidelines for the topic "Imaging of non-operated middle ear cholesteatoma" were prepared in October 2010, for the annual congress of the French Society of Otolaryngology Head and Neck Surgery (SFORL), by a panel of experts from the SFORL, represented by the French Association of Otology and Neuro-otology (AFON), and the French Radiological Society (SFR), represented by the French Society of Head and Neck Imaging (CIREOL). These guidelines are presented in the present article.

[Guidelines for the performance of MRI in patients with cochlear implants]. / Recommandations pour la réalisation d'une IRM chez un patient porteur d'implant cochléaire.

The number of patients with cochlear implant increases each year. Most of these patients may undergo MR imaging up to 1.5 Tesla, based on safety recommendations from each of the manufacturers. All external components should be removed for the examination. For three manufacturers providing about 85 % of all implanted devices in Europe, the internal components may be left in place and covered by an external bandage. Strict protocol guidelines must be implemented, especially head positioning in the magnet and within 30 cm from the bore opening. A single manufacturer, providing about 15 % of implanted devices, recommends surgical removal of the internal magnet prior to MR imaging.

Differential diagnosis and prognosis of T1-weighted post-gadolinium intralabyrinthine hyperintensities.

OBJECTIVES: The aim of this longitudinal study is to describe the different intralabyrinthine lesions yielding high signal intensity on T1-weighted (T1W) images after intravenous gadolinium and then to analyze the follow-up of these patients. METHODS: Thirty-seven patients were included and followed clinically and radiologically. A precise analysis of MR labyrinthine signals allowed exact depiction of the different lesions. Special interest is focused on the intralabyrinthine fluid signal on 3D high-resolution T2W images. RESULTS: The enhanced T1W labyrinthine hyperintensities correspond to two different categories: intralabyrinthine enhancement (15 intralabyrinthine schwannomas, 13 labyrinthitis, 1 inflammatory granuloma) and spontaneous T1W hyperintensities (8 intralabyrinthine hemorrhages). Hemorrhagic lesions show a substantial decrease of the intralabyrinthine fluid signal on the 3D HRT2 that evolves to ossification. In labyrinthitis, the importance of the initial labyrinthine fluid signal decrease on the 3D HRT2 is well correlated with the hearing prognosis. CONCLUSION: A meticulous analysis of inner ear lesions allows various intralabyrinthine lesions, in particular schwannomas, to be differentiated from labyrinthitis. T1W imaging without gadolinium is essential for the correct diagnosis of rapidly evolving hearing loss. In labyrinthitis and intralabyrinthine hemorrhage, 3D HRT2 brings an interesting prognostic factor for the chance of hearing recovery.

[Two particular cases of superior semicircular canal dehiscence related to a procidence of the superior petrous sinus]. / Deux cas particuliers de déhiscence du canal semicirculaire supérieur par déhiscence du sinus pétreux supérieur.

We report two cases of superior semicircular canal dehiscence related to a dehiscence of the superior petrous sinus that creates a localized notch of the most superior part of the superior semicircular canal. This vascular dehiscence was suspected at CT and was confirmed by MR imaging with identification of the superior petrous sinus in touch with the intralabyrinthine fluid at this level. This not well-known etiology of the superior semicircular canal dehiscence syndrome has to be searched and described by radiologists, allowing an optimal surgical approach.

[Imaging of tumors of the larynx and hypopharynx]. / Imagerie en cancérologie du larynx et de l'hypopharynx.

Evaluation of patients with laryngeal and hypopharyngeal tumors is based on multidetector CT imaging. The cervicomediastinal CT protocol and general guidelines with regards to planning and acquisition will be detailed. The primary role of imaging is accurate tumor staging but also detection of possible tumor extension to the superior aerodigestive tract and nodal areas. Therefore, images are acquired from the skull base to the cervicomediastinal junction. A chest CT must also be performed to look for distant metastases or other primary tumor. Deep tumor extension, detected only by imaging, is very important to consider for therapeutic planning: surgery or chemoradiotherapy. In case of surgery, accurate evaluation of tumor extension is of great importance to determine whether to perform partial or total surgery. Cervical nodal metastases are very common with laryngeal and hypopharyngeal carcinomas, and accurate staging of nodal disease is important.

Magnetic resonance imaging with the Digisonic SP Neurelec cochlear implant.

The goal of this study was to evaluate the MR compatibility of the Neurelec Digisonic SP cochlear implant by performing in vitro and in vivo tests. All tests were performed on 1.5 T machine. Torque and force were measured to observe a potential displacement of the internal receiver. Demagnetisation of the internal magnet was monitored inside the MRI scanner and outside the MRI scanner (in the MRI room). Potential-induced voltage on electrodes was measured in vitro, performing the usual MR sequences. Heating around the internal receiver was measured after the same MR sequences. Following in vitro tests, in vivo MR imaging (brain and posterior fossa MRI) was performed to evaluate the induced signal void and geometrical distortion. In vivo test was performed with one volunteer who had a cochlear implant device fixed to the surface of the skin with a bandage. All the in vitro tests were in compliance with standard EN 45502-2-3 relating to Cochlear Implants. In vivo MRI scans demonstrated an image distortion for spin echo sequences of 7 cm maximum around the internal magnet. Magnetic resonance imaging with the Neurelec Digisonic SP cochlear implant is possible with no measurable adverse effects for either the patient or the device. Image artefact around the internal magnet, however, is unavoidable.

Extension patterns of nasopharyngeal carcinoma.

The nasopharynx represents an intersection between the nasal choanae, the oropharynx, the deep facial spaces, the skull base and the intracranial cavity. Most nasopharyngeal neoplasms are malignant tumors showing aggressive local infiltration along well-defined routes. The primary role of imaging is accurate tumor mapping and detection of possible tumor extension, especially to the skull base and the deep facial spaces. The aim of this paper is to illustrate these extension patterns of nasopharyngeal carcinomas on imaging and to show the particular implication of imaging in the correct staging of the lesion.

[Paranasal sinuses: postoperative imaging]. / Imagerie des sinus opérés.

Radiologic assessment after sinus surgery requires not only a good knowledge of the primary disease, but also a mandatory understanding of every surgical technique and approach. After having described these techniques, we will illustrate immediate, possible but rare, post-operative complications. The various pathologies responsible for a delayed recurrence will also be illustrated. A chapter will be dedicated to paranasal sinuses malignant tumors follow up after surgery.

[Clinical implications of acoustic neuromas growth rate in volumetric study]. / Etude volumétrique de la croissance des neurinomes de l'acoustique.

OBJECTIVE: The pattern of neuroma growth is of great importance in choosing the appropriate management. This paper tests the clinical impact of tumor growth rate assessed by volumetry. There is a conviction that some slowly growing tumors could be observed for many years. METHOD AND PATIENTS: Volume measurements were performed on T1- weighted MR images (spin echo sequences) after injection of gadolinium using a special dedicated software. The studied group included 17 patients in whom at least two MRI examinations were carried out and tumor growth was confirmed. The intervals between initial and the first follow-up examination were 14.2 months on the average. In 7 cases tumor evolution was observed in 2 periods (3 MRI studies) and in 4 cases in 3 periods (4 MRI studies). RESULTS: The growth rate depended on tumors volume and clinical stage (P<0.01). Small tumors can be observed more safely than advanced tumors because their increase in mass is lower. CONCLUSION: The observation with the tumoral volume measurements appears to be a useful and accurate tool to estimate the tumor growth rate. The growth rate is a major factor for choosing the appropriate management.

Lymph node metastases from head and neck squamous cell carcinoma: MR imaging with ultrasmall superparamagnetic iron oxide particles (Sinerem MR) -- results of a phase-III multicenter clinical trial.

The aim of this study was to compare the clinical usefulness of ultrasmall superparamagnetic iron oxide (USPIO) MR contrast media (Sinerem, Guerbet Laboratories, Aulnay-sous-Bois, France) with precontrast MRI in the diagnosis of metastatic lymph nodes in patients with head and neck squamous cell carcinoma, using histology as gold standard. Eighty-one previously untreated patients were enrolled in a multicenter phase-III clinical trial. All patients had a noncontrast MR, a Sinerem MR, and surgery within a period of 15 days. The MR exams were analyzed both on site and by two independent radiologists (centralized readers). Correlation between histology and imaging was done per lymph node groups, and per individual lymph nodes when the short axis was > or = 10 mm. For individual lymph nodes, Sinerem MR showed a high sensitivity (> or = 88%) and specificity (> or = 77%). For lymph node groups, the sensitivity was > or = 59% and specificity > or = 81%. False-positive results were partially due to inflammatory nodes; false-negative results from the presence of undetected micrometastases. Errors of interpretation were also related to motion and/or susceptibility artifacts and problems of zone assignment. Sinerem MR had a negative predictive value (NPV) > or = 90% and a positive predictive value (PPV) > or = 51%. The specificity and PPV of Sinerem MR were better than those of precontrast MR. Precontrast MR showed an unexpectedly high sensitivity and NPV which were not increased with Sinerem MR. The potential contribution of Sinerem MR still remains limited by technical problems regarding motion and susceptibility artifacts and spatial resolution. It is also noteworthy that logistical problems, which could reduce the practical value of Sinerem MR, will be minimized in the future since Sinerem MR alone performed as good as the combination of precontrast and Sinerem MR.

[Cricoid chondronecrosis after prolonged endotracheal intubation]. / Chondronécrose du cricoïde après intubation prolongée.

Subglottic area injuries after prolonged endotracheal intubation are relatively frequent but cricoid cartilage necrosis is rare, with uncertain prognosis. Endoscopic findings are evocative even when clinical signs are not. When suspected, CT scan is required. The CT appearance is not specific, but the diagnosis can be strongly suggested in cases of fragmentation and collapse of the cricoid cartilage. We report two cases of cricoid chondronecrosis.

[Pendred's syndrome. Current features]. / Le syndrome de Pendred. Aspects actuels.

Introduction Pendred's syndrome is a recessive autosomal disease, traditionally defined as the association of deaf-mutism, goiter and dysfunctional iodide organization revealed by the perchlorate discharge test. It represents 4 to 10% of the causes of congenital hypoacusis. Although described more than a 100 years ago, the association of thyroid and cochleo-vestibular damage remained unclear for many years. Genetic abnormalities Progress in molecular biology has revealed that the disease is related to alterations in the PDS gene situated on chromosome 7. The PDS gene is responsible for the production of pendrine, protein involved in anion (l-, Cl-) transportation, notably in the apical pole of the thyreocyte and the cochlear duct, where the endolympha is produced. Practical implications The truncation of pendrine related to the genetic alterations be responsible for the morpho-functional alterations in the cochlear apparatus and the thyroid. In this perspective, Pendred's syndrome would appear as a genetic disorder in anion transportation.

Correlation between Ki-67 index and some clinical aspects of acoustic neuromas (vestibular schwannomas).

Evaluation of the proliferation activity of neuromas has a practical meaning when there are doubts about the complete resection of the tumor. Evaluation of the clinical aspects connected with increased proliferation activity may have a much broader application. The aim of this study was to correlate selected clinical and radiologic aspects of vestibular schwannomas with the results of the Ki-67 index. The studied group included 23 males and 20 females. Unilateral neuromas were stated in 38 cases (mean age, 52.2 years) and bilateral tumors in 5 cases (mean age, 44.2 years). The immunohistochemical tests (Ki-67) were performed on the specimens preserved in formalin and stored in paraffin. The Ki-67 index was estimated in a semiquantitative study. The mean value of Ki-67 index was 1.86%. In case of unilateral neuromas (n = 38), the average Ki-67 index was 1.74%. In 5 cases of bilateral tumors, the index amounted to 2.79% (P = 0.278). No significant correlation was found by comparing the value of the Ki-67 index with the age of patients (P = 0.410: r = 0.128). Significant differences in the value of the Ki-67 index were noted in the sub-groups of tumors that were evaluated radiologically as growing and stable. The mean value of Ki-67 index was 3.17% in the first subgroup; in stable neuromas, it was significantly lower, amounting to 1.11% (P = 0.020). Such results may confirm that the growth rate of vestibular schwannomas varies and may explain the difficulties in estimating the growth of neuromas on the basis of clinical aspects only.