CT with structured CO-RADS scoring has good diagnostic performance for COVID-19 pneumonia in both symptomatic (AUC=0.89) and asymptomatic (AUC=0.70) individuals (P<0.001). • In symptomatic individuals (42% PCR+), CO-RADS ≥ 3 detected positive PCR with acceptable sensitivity (89%) and specificity (73%) resulting in PPV of 70%. • In asymptomatic individuals (5% PCR+), CO-RADS ≥ 3 detected SARS-CoV-2 infection with low sensitivity (45%) but high specificity (89%) and PPV of 18%.

Background: chest CT is increasingly used for COVID-19 screening in healthcare systems with limited SARS-CoV-2 PCR capacity. Its diagnostic value was supported by studies with methodological concerns and its use is controversial. Here we investigated its potential to diagnose COVID-19 in symptomatic patients and to screen asymptomatic patients in a prospective study with minimal selection bias. Methods: From March 19, 2020 to April 20, 2020 we performed parallel SARS-CoV-2 PCR and CT with categorization of COVID-19 suspicion by CO-RADS, in 859 patients with COVID-19 symptoms and 1138 controls admitted to the hospital for COVID-19 unrelated medical urgencies. CT-CORADS was categorized on a 5-point scale from 1 (very low suspicion) to 5 (very high suspicion). AUC under ROC curve were calculated in symptomatic versus asymptomatic patients to predict positive SARS-CoV-2 positive PCR and likelihood ratios for each CO-RADS score were used for rational selection of diagnostic thresholds. Findings: CT-CORADS had significant (P<0.0001) diagnostic power in both symptomatic (AUC=0.891) and asymptomatic (AUC=0.700) patients hospitalized during SARS-CoV-2 peak prevalence. In symptomatic patients (41.7% PCR+), CO-RADS ≥ 3 detected positive PCR with high sensitivity (89.1%) and 72.5% specificity. In asymptomatic patients (5.3% PCR+), a CO-RADS score ≥ 3 detected SARS-CoV-2 infection with low sensitivity (45.0%) but high specificity (88.8%). Interpretation: CT-CORADS has meaningful diagnostic power in symptomatic patients, supporting its application for time-sensitive triage. Sensitivity in asymptomatic patients is insufficient to justify its use as screening approach. Incidental detection of CO-RADS ≥ 3 in asymptomatic patients should trigger reflex testing for respiratory pathogens.

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A 43-year-old textile worker consulted our hospital with a severalyear history of a painless, slowgrowing ankle mass. He had noticed the mass for the first time approxiConventional lateral radiograph of the left ankle showed a non-specific but well-defined soft-tissue mass in the posterior ankle region without obvious calcifications (Fig. 1A). The mass was located along the expected course of the Achilles tendon. Ultrasound examination clarified a well-defined lesion which was situated adjacent to the Achilles tendon and characteristics of intralesional reflections and retro-acoustic shadowing (Fig. 1B). The mass was noncompressible and no internal calcifications were seen.On MR the mass had a heterogeneous low to intermediate signal intensity pattern on theT2 weighted imaged images ( Fig. 2A), the T1-weighted appearance was consistent, with a homogeneously low to mately 5 years previously as a small lump, painlessly increasing in size over time.The medical history of the patient revealed that he had visited an orthopaedic surgeon 12 months earlier for anterior knee pain which was conservatively treated. Physical examination noted a normal gait. Inspection and palpation showed an obvious, firm and mobile mass situated in the posterior-medial aspect of the ankle and adjacent to the Achilles tendon. It was tender, measuring approximately 2,5 cm. His muscle bulk, strength, reflexes, and sensation were enterily normal. No obvious vascular findings were found. The patient had a normal neurologic status with no Tinel's sign of the sural nerve. , 2015, 98: 34-36. JBR-BTR Pseudotumoral toPhaCeous involvement of the aChilles ParatenonT. Ryckaert, I. Crevits, S. Brijs, G. Debakker, F. Rosseel, A. Tieleman, R. De Man 1 Gout is the most common form of microcrystalline arthropathy which usually does not pose a diagnostic challenge when patients have typical presentation, appropriate biochemical picture and classical radiographic appearance. however, formation of gouty tophi in unusual locations and with atypical presentations may mislead clinicians and radiologists, thereby justifying gout nickname as the "great mimicker". When interpreting images of tendon related masses, radiologists should be aware of gouty tophi as a possible differential given its variable and nonspecific imaging appearance. in this article, we present a case of a patient with a painless tophaceous gout nodule, adjacent to the achilles tendon.