Primary urethral carcinoma: Recommendations of the oncology committee of the French Urology Association.

Primary urethral carcinoma (PUC) is defined as a tumor process arising within the urethra, with no history of other urinary tract localization or synchronous tumor of the urinary tract. The most common histological types are urothelial carcinoma (UC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). In men, UC predominates, while AC is rare. In women, AC affects around one in two patients, while EC and UC are equally divided between the remaining cases. Diagnosis is often delayed, and requires endoscopic examination with biopsies. MRI is the gold standard for local staging. FDG-PET scan can help in cases of doubt about regional or distant extension. The prognosis remains unfavorable despite aggressive surgical treatment. Multimodal management combining surgery, radiotherapy and chemotherapy appears to improve prognosis in severe forms.

[First-line management of infertile couple. Guidelines for clinical practice of the French College of Obstetricians and Gynecologists 2022]. / Prise en charge de première intention du couple infertile : mise à jour des RPC 2010 du CNGOF.

OBJECTIVE: To update the 2010 CNGOF clinical practice guidelines for the first-line management of infertile couples. MATERIALS AND METHODS: Five major themes (first-line assessment of the infertile woman, first-line assessment of the infertile man, prevention of exposure to environmental factors, initial management using ovulation induction regimens, first-line reproductive surgery) were identified, enabling 28 questions to be formulated using the Patients, Intervention, Comparison, Outcome (PICO) format. Each question was addressed by a working group that had carried out a systematic review of the literature since 2010, and followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) methodology to assess the quality of the scientific data on which the recommendations were based. These recommendations were then validated during a national review by 40 national experts. RESULTS: The fertility work-up is recommended to be prescribed according to the woman's age: after one year of infertility before the age of 35 and after 6months after the age of 35. A couple's initial infertility work-up includes a single 3D ultrasound scan with antral follicle count, assessment of tubal permeability by hysterography or HyFOSy, anti-Mullerian hormone assay prior to assisted reproduction, and vaginal swabbing for vaginosis. If the 3D ultrasound is normal, hysterosonography and diagnostic hysteroscopy are not recommended as first-line procedures. Chlamydia trachomatis serology does not have the necessary performance to predict tubal patency. Post-coital testing is no longer recommended. In men, spermogram, spermocytogram and spermoculture are recommended as first-line tests. If the spermogram is normal, it is not recommended to check the spermogram. If the spermogram is abnormal, an examination by an andrologist, an ultrasound scan of the testicles and hormonal test are recommended. Based on the data in the literature, we are unable to recommend a BMI threshold for women that would contraindicate medical management of infertility. A well-balanced Mediterranean-style diet, physical activity and the cessation of smoking and cannabis are recommended for infertile couples. For fertility concern, it is recommended to limit alcohol consumption to less than 5 glasses a week. If the infertility work-up reveals no abnormalities, ovulation induction is not recommended for normo-ovulatory women. If intrauterine insemination is indicated based on an abnormal infertility work-up, gonadotropin stimulation and ovulation monitoring are recommended to avoid multiple pregnancies. If the infertility work-up reveals no abnormality, laparoscopy is probably recommended before the age of 30 to increase natural pregnancy rates. In the case of hydrosalpinx, surgical management is recommended prior to ART, with either salpingotomy or salpingectomy depending on the tubal score. It is recommended to operate on polyps>10mm, myomas 0, 1, 2 and synechiae prior to ART. The data in the literature do not allow us to systematically recommend asymptomatic uterine septa and isthmoceles as first-line surgery. CONCLUSION: Based on strong agreement between experts, we have been able to formulate updated recommendations in 28 areas concerning the initial management of infertile couples.

[French recommendations for malignant pheochromocytomas and paragangliomas by the national ENDOCAN-COMETE network]. / Recommandations du réseau national ENDOCAN-COMETE pour la prise en charge des phéochromocytomes et paragangliomes métastatiques.

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors, developed respectively in the adrenal medulla and in extra-adrenal locations. Their malignancy is defined by the presence of distant metastases. Forty percent of them are inherited and can be part of different hereditary syndromes. Their management is ensured in France by the multidisciplinary expert centers of the ENDOCAN-COMETE national network "Cancers of the Adrenal gland", certified by the National Cancer Institute and discussed within multidisciplinary team meetings. The diagnostic and therapeutic work-up must be standardized, based on an expert analysis of clinical symptoms, hormonal biological secretions, genetics, morphological and specific metabolic imaging. In the context of a heterogeneous survival sometimes beyond seven to ten years, therapeutic intervention must be justified. This is multidisciplinary and relies on surgery, interventional radiology, external or internal radiotherapy and medical treatments such as sunitinib or dacarbazine and temodal chemotherapy. The personalized approach based on functional imaging fixation status and genetics is progressing despite the extreme rarity of this disease.

[Guidelines of the French National ENDOCAN-COMETE, Association of Endocrine Surgery, Society of Urology for the management of adrenocortical carcinoma]. / Recommandations conjointes du réseau National ENDOCAN-COMETE, de l'Association francophone de chirurgie endocrinienne et de la Société française d'urologie pour la prise en charge du carcinome corticosurrénalien.

The adrenocortical carcinoma (ACC) is a primary malignant tumor developed from the adrenal cortex, defined by a Weiss score≥3. Its prognosis is poor and depends mainly on the stage of the disease at diagnosis. Care is organized in France by the multidisciplinary expert centers of the national ENDOCAN-COMETE "Adrenal Cancers" network, certified by the National Cancer Institute. This document updates the guidelines for the management of ACC in adults based on the most robust data in the literature. It's divided into 11 chapters: (1) circumstances of discovery; (2) pre-therapeutic assessment; (3) diagnosis of ACC; (4) oncogenetics; (5) prognostic classifications; (6) treatment of hormonal hypersecretion; (7) treatment of localized forms; (8) treatment of relapses; (9) treatment of advanced forms; (10) follow-up; (11) the particular case of ACC and pregnancy. R0 resection of all localized ACC remains an unmet need and it must be performed in expert centers. Flow-charts for the therapeutic management of localized ACC, relapse or advanced ACC are provided. It was written by the experts from the national ENDOCAN-COMETE network and validated by all French Societies involved in the management of these patients (endocrinology, medical oncology, endocrine surgery, urology, pathology, genetics, nuclear medicine, radiology, interventional radiology).

The Role of CT in the Staging and Follow-Up of Testicular Tumors: Baseline, Recurrence and Pitfalls.

Ultrasound imaging of the testis represents the standard-of-care initial imaging for the diagnosis of TGCT, whereas computed tomography (CT) plays an integral role in the initial accurate disease staging (organ-confined, regional lymph nodes, or sites of distant metastases), in monitoring the response to therapy in patients who initially present with non-confined disease, in planning surgical approaches for residual masses, in conducting follow-up surveillance and in determining the extent of recurrence in patients who relapse after treatment completion. CT imaging has also an important place in diagnosing complications of treatments. The aims of this article are to review these different roles of CT in primary TGCT and focus on different pitfalls that radiologists need to be aware of.

Ultrasound and Magnetic Resonance Imaging of Burned-Out Testicular Tumours: The Diagnostic Keys Based on 48 Cases.

The spontaneous regression of testicular germ-cell tumours is a rare event whose mechanisms have yet to be elucidated. In the majority of published cases, tumour regression is concomitant with the metastatic development of the disease. Residual lesions, often referred to as burned-out testicular tumours (BOTTs), are difficult to diagnose due to the paucity of published data, especially in the field of imaging. The aim of this article is to describe the radiological signs of BOTTs on multimodal ultrasound and multiparametric MRI from a series of 48 patients whose diagnosis was confirmed histologically. The demographic, clinical and laboratory characteristics of the patients are studied, as well as the data of the imaging examinations, including conventional scrotal ultrasound, shear-wave elastography, contrast-enhanced ultrasound (CEUS) and multiparametric MRI. A total of 27 out of 48 patients were referred for investigation of primary testicular lesion following the discovery of retroperitoneal metastases, 18/48 patients were referred because of lesions suspected on an ultrasound that was performed for an infertility work-up, and 3/48 were referred because of scrotal clinical signs. Of these last 21 patients (infertility work-up/scrotal clinical sign), 6 were found to be metastatic on the extension work-up. Of the 48 orchiectomy specimens, tumour involution was complete in 41 cases, and a small active contingent remained in 7 cases, with 6 suspected upon advanced US and MRI. Typically, BOTTs appear on a conventional ultrasound as ill-delineated, hypoechoic and hypovascular nodular areas. Clustered microliths (60.4%) and macrocalcifications (35.4%) were frequent. Shear-wave elastography showed areas of focal induration (13.5 ± 8.4 vs. 2.7 ± 1.2 kPa for normal parenchyma, p < 0.01) in 92.5% of the patients for whom it was performed, and contrast ultrasonography demonstrated hypoperfusion of these lesions. Of the 42 MRIs performed, BOTTs corresponded to nodules on T2-weighted sequences (hyposignal) with significantly increased ADC values compared with healthy parenchyma (2 ± 0.3 versus 1.3 ± 0.3 × 10−3 mm2/s, p < 0.01) and an enhancement defect after injection. This enhancement defect overlapped the lesions visible on T2-weighted sequences in most cases. In the case of predominant partial regression, an enhanced portion after contrast injection was visible on MRI in all seven patients of our series, and in six of them a focal diffusion restriction zone was also present. Spontaneously involuted testicular germ-cell tumours have specific radiological signs, and all of the mentioned examinations contribute to this difficult diagnosis, even histologically, because there is no tumour cell left. These signs are similar whether the patient is initially symptomatic metastatic or whether the discovery is fortuitous on the occasion of an infertility work-up, and whatever the seminomatous or non-seminomatous nature of the germ-cell tumour, when this can be determined. The appearance of regressed germ-cell tumours is often trivialized, which can lead to the wrong diagnosis of an extra gonadal germ-cell tumour (in metastatic patients) or of scarring from an acute event such as trauma or infection, which is not recognized or forgotten. In our series, two patients had an unrecognized diagnosis in their history, with local and/or distant recurrence. An improvement in diagnosing burned-out tumours, combining advanced US and MRI, is necessary in order to optimize patient management, with special attention paid to asymptomatic patients, to prompt extension screening and orchiectomy with analysis of the whole testis. This may reveal a persistent viable tumour or lesions of germinal neoplasia in situ, which are precursors of testicular germ-cell tumours.

Leydig Cell Tumors of the Testis: An Update of the Imaging Characteristics of a Not So Rare Lesion.

Pre-operative testicular tumor characterization is a challenge for radiologists and urologists. New data concerning imaging approaches or immunochemistry markers improve the management of patients presenting with a testicular tumor, sometimes avoiding radical orchiectomy. In the past 20 years, imaging modalities, especially ultrasound (US) and magnetic resonance imaging (MRI), improved, allowing for great progress in lesion characterization. Leydig cell tumors (LCT) are rare testicular tumors developing from the stromal tissue, with relatively scarce literature, as most of the studies focus on the much more frequent germ cell tumors. However, with the increase in testicular sonography numbers, the incidence of LCT appears much higher than expected, with some studies reporting up to 22% of small testicular nodules. Multimodal ultrasound using Doppler, Elastography, or injection of contrast media can provide crucial arguments to differentiate LCT from germ cell tumors. Multiparametric MRI is a second intention exam, but it allows for extraction of quantifiable data to assess the diagnosis of LCT. The aims of this article are to review the latest data regarding LCT imaging features, using multimodal ultrasound and multiparametric MRI, and to focus on the peculiar aspect of the testis of patients with Klinefelter's syndrome. The possibility of an LCT should be raised in front of a small hypoechoic tumor with a marked corbelling hypervascularization in an otherwise normal testicular pulp. Ultrasonographic modules, such as ultrasensitive Doppler, contrast-enhanced ultrasonography, or elastography, can be used to reinforce the suspicion of LCT. MRI provides objective data regarding vascularization and enhancement kinetics.

Renal involvement of lymphomas proven by kidney biopsy: report of 10 cases from a tertiary care center and comparison with the literature.

Lymphomas localized in the kidney are a rare entity that may be challenging to diagnose. We analyzed data from 10 patients with renal involvement of lymphoma diagnosed between 2009 and 2019 on fine needle biopsy from our tertiary center, and compared these with findings of 160 cases reported in the literature. Diffuse large B-cell lymphoma was the main histology subtype (40 and 38% in our sample and in the literature, respectively), followed by low-grade B-cell lymphomas, mostly from the marginal zone (MZ). Altogether, 106 patients had urological inaugural symptoms and 64 had general symptoms. Patients with urological presentation more often had renal masses than diffuse infiltration (p < 0.001), unilateral tumors (p = 0.0036) and low-grade B-cell lymphomas (17 vs 6%, p = 0.043). In both groups, nearly one-fourth of patients had diffuse (stage IV) lymphomas. Overall survival did not differ by the presence of urological/systemic symptoms, stage or aggressive lymphoma status. Notably, 3 of 10 patients from our series had MZ lymphomas associated with primary Sjögren syndrome revealed by acute kidney injury, including one where the autoimmune disease was detected. Lymphoproliferative disorders localized in the kidney are a challenging condition that can lead to detection of aggressive or diffuse lymphomas.

Predicting the Need for Surgery in Uncomplicated Adhesive Small Bowel Obstruction: A Scoring Tool.

INTRODUCTION: Nonoperative treatment can be attempted for uncomplicated adhesive small bowel obstruction (ASBO), but carries a risk of delayed surgery. Highlighting initial parameters predicting risk of failure of nonoperative management would be of great interest. METHODS: Patients initially managed conservatively for uncomplicated ASBO were retrospectively analyzed. Univariate and multivariate analysis were performed to identify predictive failure's factors. Based on the risk factors, a score was created and then prospectively validated in a different patients' population. RESULTS: Among 171 patients included, 98 (57.3%) were successfully managed conservatively. In a multivariate analysis, three independent nonoperative management failure's factors were identified: Charlson Index ≥4 (P = 0.016), distal obstruction (P = 0.009), and maximum small bowel diameter over vertical abdominal diameter ratio >0.34 (P = 0.023). A score of two or three was associated with a risk of surgery of 51.4% or 70.3% in the retrospective analysis and 62.2% or 75% in the validation cohort, respectively. CONCLUSIONS: This clinical-radiological score may help guide surgical decision-making in uncomplicated ASBO. A high score (≥2) was predictive of failure of nonoperative management. This tool could assist surgeons to determine who would benefit from early surgery.

Precocious puberty related to Leydig cell testicular tumor: the diagnostic imaging keys.

BACKGROUND: We report the challenging case of a 6-year-old boy with precocious puberty related to histologically proven Leydig cell tumor. CASE PRESENTATION: Multiparametric ultrasound and magnetic resonance imaging (MRI) was performed. Interesting findings were scarcely or never reported in children and differed from adults Leydig cell tumors s such as the hyperechogenic halo surrounding the lesion and the dominant central vascularization using ultrasensitive Doppler. MRI revealed an enlarged testicle with strong enhancement of a tumor, a tumor apparent diffusion coefficient (ADC) of 600 × 10-3 mm2/s and a lower ADC value of the non-tumor parenchyma compared to the contralateral testis (ADC = 800 × 10-3 mm2/s vs 1100 × 10-3 mm2/s), attributed to the spermatogenesis induced by hormonal impregnation. CONCLUSION: We illustrate multiparametric US and MRI findings of a pediatric Leydig cell tumor, including the imaging changes attributed to local hormone secretion, which may be helpful in similar cases.

Computed tomography assessment of postoperative gastric vascular supply and staple-line leak development after sleeve gastrectomy.

BACKGROUND: Residual arterial supply of the gastric tube after sleeve gastrectomy (SG) can be damaged by surgery, which can reduce gastric tube perfusion and could promote postoperative leakage. OBJECTIVE: To compare the postoperative vascularization of the gastric tube using early computed tomography (CT) scanning after SG in patients with or without postoperative staple-line leak. SETTING: University hospital. METHODS: A retrospective analysis of a prospective database was performed in consecutive patients undergoing SG. Patients who presented with a staple-line leak were matched (1:3) with a control group of patients who underwent surgery without postoperative morbidity during the same period. Gastric tube vascularization was studied on a postoperative day 2 CT scan in both groups of patients. RESULTS: During the study period, 1826 patients underwent SG, including 42 patients (2.3%) who presented with a staple-line leak. Those 42 patients were successfully matched to 126 control patients. Global identification of residual gastric arterial supply in early postoperative CT scans was similar in patients with or without staple-line leak after SG. However, residual vascular supply of the gastroesophageal junction (i.e., terminal and anterior cardiotuberosity branches of the left gastric artery or left inferior phrenic artery) was more frequently interrupted by the staple line in the group of patients who developed a gastric leak. CONCLUSION: This study suggests a correlation between interruption of the main arteries supplying the gastroesophageal junction by the staple line on early postoperative CT scans and the development of gastric leak after SG. These results support the vascular theory as one of the causes of leak after SG.

Routine Early Computed Tomography Scanner After Laparoscopic Sleeve Gastrectomy in High-Risk Severely Obese Patients Is Effective for Bleeding or Hematoma Diagnosis but not for Staple-Line Leak Detection: a Prospective Study.

PURPOSE: Laparoscopic sleeve gastrectomy (LSG) is the most frequently performed bariatric procedure worldwide. Postoperative staple-line leak and intraabdominal hemorrhage can increase associated morbidity and mortality. The value of routine early computed tomography (CT) scanner examination in the early diagnosis of complications in high-risk severely obese patients undergoing LSG is studied. METHODS: This was a prospective, non-randomized study including all patients undergoing LSG in our department from 2014 to 2020. Patients presenting at least one potential risk factor for postoperative gastric leak and bleeding (as defined by the current literature) were included. Primary endpoint was the efficacy of postoperative day (POD) 2 CT-scanner examination in diagnosing these complications. RESULTS: One thousand fifty-one high-risk patients were included. Median age was 44 years. Early postoperative surgical complications occurred in 48 patients (4.5%): 25 (2.3%) intraabdominal hemorrhage and 23 (2.2%) staple-line leak. Early CT-scanner detected intraabdominal bleeding or hematoma in 22/25 patients, with 95.6% sensitivity (Youden's index = 0.95), while specificity was 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 99.9%. Sensitivity of early postoperative CT-scanner was 43.4% (10/23 patients; Youden's index = 0.43) for staple-line leak detection, with specificity of 100%, PPV 100%, and NPV 98.7%. CONCLUSION: POD 2 CT-scanner in high-risk severely obese patients undergoing LSG is an excellent tool for early diagnosis of intraabdominal hemorrhage, but sensitivity remains low for staple-line leak detection. Close postoperative clinical follow-up of these patients is essential and any suspicion of postoperative surgical complication should motivate the performance of a CT-scanner.

Prevention of incisional hernia after single-port sleeve gastrectomy (PRISM): a prospective non-randomized controlled study.

BACKGROUND: SPSG carries a risk of incisional hernia, particularly in patients with high body mass index. Prophylactic mesh placement with either permanent or absorbable mesh could decrease the occurrence of incisional hernia, with uncertainty on other postoperative parietal complications. METHODS: This is a non-randomized monocentric single-blinded prospective study. High-risk patients (body mass index ≥ 45 kg/m2) underwent either 3 strategies of parietal closure (suture with or without permanent or absorbable mesh) during SPSG. The primary outcome was the occurrence of radiologically defined incisional hernia during the first postoperative year. Secondary outcomes included surgical site infection rates and postoperative pain. RESULTS: Between November 2018 and November 2019, 255 patients were included (85 in each group). All patients reached one-year postoperative follow-up. Significantly more incisional hernias were observed in the no mesh group in comparison with permanent and absorbable mesh groups, respectively (20% vs. 7.1% vs. 5.1%, P = 0.005). No difference was observed in mesh groups. No difference was observed regarding other parietal complications. One patient in the absorbable mesh group presented a superficial surgical site infection and required surgical drainage without mesh removal and one patient in the permanent mesh group presented a parietal hematoma and required surgical drainage with mesh removal. Twenty-six (92.8%) asymptomatic patients presented incisional hernia discovered on the one-year CT-scan. CONCLUSIONS: Prophylactic mesh placement during SPSG decreases the occurrence of postoperative incisional hernia. Routine permanent mesh placement could be proposed in high-risk patients.

How to perform shear wave elastography. Part I.

We recently introduced a series of papers describing how to do certain techniques. This article is the first part of a review of shear wave elastography (SWE). It reports the principles and interpretation of the technique and describes how to optimize it. Normal values, pitfalls and artefacts for the examination of liver, breast. thyroid and salivary gland with shear wave elastography are presented. The manuscript provides specific tips for applying SWE as part of a diagnostic US examination.

How to perform shear wave elastography. Part II.

Recently a series of papers was introduced describing on "how to do" certain techniques. More specifically we published on how to perform strain imaging using the transcutaneous and endoscopic ultrasound approach and shear wave elastography (SWE). In the first part we describe how to optimize the examination technique, discussing normal values, pitfalls, artefacts and specific tips for applying SWE to specific organs (liver, breast, thyroid, salivary glands) as part of a diagnostic US examination. In part II, the use of SWE in the pancreas, spleen, kidney, prostate, scrotum, musculoskeletal system, lymph nodes and future developments are discussed.

Testicular Lesions in Infertile Men.

OBJECTIVES: An increasing number of incidental testicular tumors are diagnosed in patients during infertility workup. The aim of this study was to evaluate the accuracy of frozen section examination (FSE) for the management of these tumors. METHODS: We retrospectively studied a series of 46 testicular tumors diagnosed during exploration for infertility from 2000 to 2019 and submitted for FSE. RESULTS: A diagnosis of malignancy was made in 23 cases on both gross examination (yellow-white or cream-colored nodules for seminomas) and FSE, then confirmed on final diagnosis in 22 of the cases. One seminoma reported on FSE was revised as being a Leydig cell tumor. The 23 other lesions were diagnosed as benign on FSE, including 11 Leydig cell tumors (yellow-brown nodules), 2 Leydig cell hyperplasias, and 10 whitish fibrous lesions. All Leydig cell lesions were confirmed except 1, which was reclassified as a Sertoli cell tumor. Of the 10 cases of fibrous lesions, 6 were associated with malignancy. CONCLUSIONS: The high incidence of Leydig cell tumors and the accuracy of FSE for these lesions demonstrate the interest in FSE. In contrast, FSE is not reliable for fibrous lesions, and surgeons should be aware that a fibrosis result often corresponds with regressed tumors.

Current strategies to induce liver remnant hypertrophy before major liver resection.

Hepatic resection is the gold standard for patients affected by primary or metastatic liver tumors but is hampered by the risk of post-hepatectomy liver failure. Despite recent improvements, liver surgery still requires excellent clinical judgement in selecting patients for surgery and, above all, efficient pre-operative strategies to provide adequate future liver remnant. The aim of this article is to review the literature on the rational, the preliminary assessment, the advantages as well as the limits of each existing technique for preparing the liver for major hepatectomy.

Non-Hemorrhagic Adrenal Infarction during Pregnancy: The Diagnostic Imaging Keys.

Background: non-hemorrhagic adrenal infarction (NHAI) is a rare cause of acute abdominal/flank pain during pregnancy; in order to ensure prompt and appropriate treatment, this diagnosis should not be overlooked. This case series highlights pertinent imaging findings, including ultrasounds (USs), computed tomography (CT), and magnetic resonance imaging (MRI) of recent NHAI cases. Methods: we compiled all consecutive NHAI cases from two university hospitals over a two-year period and checked the relevant clinical, laboratory, and imaging findings. Relevant articles on NHAI published from January 2010 to March 2021 were analyzed. Results: six cases were found in our database. CT-scans typically showed enlarged, hypodense, and non-enhanced adrenal glands. Unenhanced MRIs allowed for diagnoses and showed enlarged adrenal glands in the signal hyperintensity on T2 and diffusion-weighted imaging, without any signal hyperintensity on T1. In two of our six cases, USs showed swollen adrenal glands with fluid collection. Conclusion: NHAI and its differential diagnosis-in cases of acute pain during pregnancy-highlight the crucial roles of integrated radiological examination and cooperation between obstetricians and radiologists, both of whom should consider the location of the pain, the accessibility and tolerance of MRI, and the radiation exposure of CT. Despite its supposed poor sensitivity, an US performed because the patient reports pain should also be used to examine the adrenal gland regions. Non-enhanced MRI is clearly of value and access to it in emergencies is important to avoid radiation exposure.

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.