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.

[Can breast elastography change our strategies? Technology, impact and limitations]. / L'élastographie du sein peut-elle modifier nos stratégies ? Technologie, impact et limites.

Compression or static elastography is based on images deformation (induced by slight manual compression/decompression to the breast) and tissue movement is color-encoded in color map and classified into five scores of increasing malignancy (score of 1 to 3: benign and 4 to 5: malignant). The elasticity shear wave is measured from the propagation velocity of shear waves in the lesions and is expressed in kPa or m/s and in color map. Reproducibility is satisfactory for the two technologies even if the static elastography is only semi-quantitative. Elastography is helpful for lesions classified BI-RADS 3 and 4 and especially when the PPV of these lesions in B mode is low<10% (BI-RADS 3 and 4a). For these two technologies, cancer and biopsy rates are reduced by at least 30% (with threshold values for the shear wave technology of 30kPa and 3m/s depending on the manufacturer). False positives are found with the fibrotic lesions and false negatives by colloid tumors and DCIS. Correlation with prognostic factors is discussed.

[Breast cancer screening imaging: what do we do]. / Dépistage du cancer du sein : quelle imagerie pour quelles femmes?

The purpose of this review is to evaluate the value of different breast imaging technics and their place for individual and mass screening of breast cancer according to the randomized studies on digital mammography and ultrasound screening. Analogic and numerical mammograms are validated for screening of women aged from 50 and 74 years. The additional value of ultrasound is therefore proven when the increased risk is moderate. When risk is higher (genetic or familial), MRI is the method of choice associated with conventional imaging. Individual screening is recommended before 50 for women aged from 45 and 50 and for those over 74 using the same procedures as organized screening.

[Multinodular hepatopathy with fever in a tropical climate: hepatic amebiasis with multiple abscesses]. / Une hépatopathie multinodulaire fébrile en zone tropicale.

Hepatic amebiasis is common in tropical zones. Solitary abscess is the classical form but multinodular presentation does not rule out amebiasis as the underlying cause. Definitive diagnosis cannot be based on clinical and radiologic findings alone. Serological testing for amebiasis is necessary. In zones where serology is unavailable, response to presumptive metronidazole treatment is still a useful for diagnosis.

[MR imaging evaluation of endometrial carcinoma]. / Evaluation en imagerie par résonance magnétique des carcinomes de l'endomètre.

Prognosis for endometrial carcinoma is closely related to cell type and tumor grade but also to local staging using the FIGO classification. MRI, under specific technical conditions, allows excellent depiction of the degree of myometrial tumor extension. It also has an excellent specificity for the detection of cervical extension. In addition, it allows evaluation of regional nodes, but with sensitivity values that are not perfect. The purpose of this paper is to review the MR imaging features of endometrial carcinoma along with its limitations and pitfalls.

[Deep pelvic endometriosis: MRI features]. / Endométriose pelvienne profonde en IRM.

Endometriosis is a frequent pathology of adult women. Clinical examination and US are poorly sensitive for detection of deep pelvic implants and MRI is superior for presurgical mapping of disease extent. This is important to optimize complete surgical excision, the only proven treatment to achieve symptomatic relief. The purpose of this pictorial essay is to describe the imaging features of deep pelvic endometriosis and the technical means to optimize its detection.

Incarceration of the appendix complicating a uterine perforation following surgical abortion: CT aspects.

A 39-year-old patient was evaluated for pelvic pain and infection following a surgical abortion performed via aspiration curettage. A pelvic computed tomography (CT) revealed an invagination of fat in the uterine wall accompanied by an abscess in the rectouterine pouch. Laparoscopic exploration revealed an incarcerated cecal appendix within the myometrium with necrosis of the appendiceal base as the culprit. A posteriori, CT multiplanar reconstruction allowed identification of the incarcerated appendix within the myometrium. To our knowledge, this CT description is the only case described in the literature.

[Percutaneous vertebroplasty in symptomatic osteoporotic vertebral compression fractures: review of 50 patients]. / Résultats de la vertébroplastie percutanée dans le traitement des fractures vertébrales ostéoporotiques hyperalgiques (50 cas).

PURPOSE: Evaluation of percutaneous vertebroplasty (PVP) in symptomatic osteoporotic vertebral compression fractures after failure of conservative management. MATERIALS AND METHODS: Retrospective study of cases performed between 2002 and 2005 in a single institution. Outcome was measured using Huskisson's visual analogue scale. RESULTS: A total of 77 vertebrae in 50 patients were treated. Mean follow-up was 12.9 months (1-36 months). Significant symptomatic improvement (p<0.001) was noted with pre PVP pain score of 7.4 (+/-0.99), 24 hour and 1 month post PVP score of 2.31 (+/-2.65), 6 month post PVP score of 2.4 (+/-2.7) and 18 month post PVP score of 2.91 (+/-2.91). Seven patients presented with a new symptomatic vertebral compression fracture, with 5 cases adjacent to the treated level. CONCLUSION: Percutaneous vertebroplasty is reliable and effective in the treatment of symptomatic osteoporotic vertebral compression fractures.

[Imaging of inflammatory pseudotumors of the liver]. / Imagerie des pseudo-tumeurs inflammatoires hépatiques.

PURPOSE: To describe the imaging features of inflammatory pseudotumors of the liver. INTRODUCTION: Inflammatory pseudotumors of the liver are rare benign lesions that may simulate malignancy on imaging studies. Diagnosis is most frequently confirmed after surgical resection of the lesion. MATERIALS AND METHODS: Retrospective study from 1998 to 2006 of histologically proven cases of inflammatory pseudotumors of the liver. A combination of the following imaging modalities were utilized: US, contrast enhanced US, helical CT and MRI. RESULTS: A total of seven lesions (mean diameter of 61.4 mm) were detected in 6 patients (mean age of 66 years). Clinical and laboratory results were non-specific. The following imaging studies were available: US in 5 cases, including one with contrast material, CT in 5 cases and MRI in 3 cases. All tumors were hypoechoic on US, with no enhancement after injection of Levovist. The tumors were generally hypodense on noncontrast CT and enhancement, when present, was delayed and moderate. On MRI, the tumors were iso- or slightly hyperintense on T2W images and iso- or slightly hypointense on T1W images with subtle peripheral enhancement on delayed imaging. CONCLUSION: The differential diagnosis of inflammatory pseudotumor of the liver should be known to radiologists and could be suggested in a clinical context of chronic inflammatory process in patients with non-specific liver mass showing imaging features of partial fibrosis with delayed enhancement.

[MR Features of hepatic macronodular mycobacteriosis]. / IRM des atteintes macronodulaires hépatiques à mycobactéries.

Hepatic macronodular mycobacteriosis is rare. Its diagnosis is challenging and is most often proposed on the basis of histological analysis. Final diagnosis, except for germ-proven cases, is made in conjunction with clinical, biological, and radiological arguments. We retrospectively report the MR features of ten hepatic lesions discovered on five patients. MRI is sensitive but has a low specificity in demonstrating pseudotumoral lesions most often exhibiting hypointensity on the T1-weighted sequence, hyperintensity on the T2-weighted sequence, and a slight rim enhancement after gadolinium-enhanced T1-weighted sequences.

Pelvic prolapse: static and dynamic MRI.

Pelvic magnetic resonance is a simple and non-invasive imaging technique for dynamic and static assessment of the pelvic floor. The morphology of the support system is assessed by T2-weighted images. Dynamic sequences are used to assess pelvic prolapse. In this study we illustrate the normal and pathologic features of the levator ani muscle which represents the main active support of pelvic organs. Furthermore we describe the different types of prolapses, floor by floor, and the different staging techniques.

MR features of gastrointestinal stromal tumors.

We report on two patients presenting with gastrointestinal stromal tumors (GIST). The important tumor size and the marked tissular hypersignal seen on T2-weighted magnetic resonance images (MRI) should be considered as magnetic resonance (MR) features strongly indicating diagnosis of GIST.