Almeida RR, et al. - Through a retrospective analysis of chest CT scans collected between 2007 and 2017 that had findings of septic pulmonary embolism (PE) related to IV substance use disorder, experts evaluate the “reversed halo” sign in 62 people with septic PE because of IV substance use disorder. Reversed halo signs were seen in 59.7%. Of 78 novel reversed halo signs 93.6% and 51.3% were peripherally located and located at the lower lobe; 52.6% and 47.4% were pyramidal and round-shaped; and 89.7% and 34.6% had central low-attenuation areas and internal reticulations, respectively. In 37.2% of reversed halo signs, the development of cavitation was seen especially more frequently in pyramid-shaped ones, whereas consolidation transpired in 30.8% and more frequently in round-shaped ones. In summary, in the differential diagnosis of people with IV substance use disorder presenting with reversed halo sign, septic PE should be taken into consideration. On the chest CT scans of people with IV substance use disorder-related septic PE, the reversed halo sign was reliably and often seen. Moreover, to distinguish septic PE from other causes of pulmonary infarct showing with reversed halo sign, features of reversed halo sign presentation were recognized as possible characteristics.