Spontaneous pneumomediastinum is a rare but potentially life-threatening condition, the incidence of which has showed an increase in patients with SARS-CoV-2 pneumonia, especially when they are on positive pressure ventilation. None of the reported cases of covid related pneumomediastinum had an associated tracheal diverticulum. Also, to the best of our knowledge, tracheal diverticulum has not been reported in patients on NIV. We report 2 cases of COVID-19 pneumonia on NIV with pneumomediastinum, which also had associated tracheal diverticulum, one of which developed after NIV. Though the establishment of causality needs further research, early detection of a tracheal diverticulum, which might be a harbinger of pneumomediastinum, can be a timely alarm to prompt titration of the pressure settings and judicious use of NIV. The role of inverted grey scale CT images in mediastinal window is a simple, yet hardly utilised radiological tool to increase detection of ‘mediastinal air’, let it be free air or air within a diverticulum. Through this case report, we would like to highlight the role of conventional and inverted CT imaging of pneumomediastinum and tracheal diverticulum in general and in SARS-CoV-2 pneumonia in particular, and to call for more objective research to throw light on the plausible relationship between pneumomediastinum and tracheal diverticulum.

Mueller Weiss Syndrome is a rare, under-diagnosed cause of chronic mid foot pain despite having well-described imaging features. It is historically described as spontaneous adult-onset osteonecrosis of the navicular bone. The disease commonly affects bilateral navicular bones in women in the fifth decade of life. Nearly a century after its first description as a disease entity, the exact etiopathogenesis is still not well understood. From a radiographic point of view weight-bearing radiographs of the foot remains the mainstay in diagnosis. Characteristic imaging findings include the lateral collapse of navicular, dorsomedial subluxation of the remnant navicular, and lateral deviation of the talus (hind-foot varus). Progressive disease leads to pes planus and secondary osteoarthritis of the talonavicular joint with or without the involvement of other midfoot joints. Severe disease may show “listhesis navicularis” and talo-cuneiform neo-articulation. Computed tomography and magnetic resonance imaging can be used as adjuncts, especially to detect changes in the initial stage of the disease and early osteoarthritic features.