Unusual Air Crescents on Chest Radiographs.

The air crescent (AC) is a common radiological sign. Even if its commonest aetiology remains pulmonary aspergillosis, various other causes have been described. In this study, we report four rare causes of ACs seen on chest radiographs that haven't been described in the literature. Teaching point: The differential diagnosis of an air crescent sign on chest radiographs includes oesophageal bezoar, interstitial lung emphysema, central bronchial stenosis and perforated emphysematous cholecystitis.

Aerated Lobar Collapse.

Teaching Point: Air trapping is a useful sign for early detection of worsening lobar collapse in the follow-up of obstructive atelectasis.

An Avoidable Cognitive Error in Chest Radiography.

Teaching Point: Awareness in radiology reporting of cognitive errors such as the alliterative bias can help minimize the delay to diagnosis and accelerate adequate patient care.

Splenic and Portal Vein Thrombosis after Splenectomy: A Case Report.

Portal and splenic vein thrombosis are uncommon, potentially fatal post-operative complications following splenectomy. These thrombotic events may be asymptomatic or present with non-specific symptoms. Therefore, imaging is important for diagnosis. The risk of thrombosis is linked to spleen size, pre-operative thrombocytopenia and surgical technique. We present the case of a 40-year-old man who underwent curative and diagnostic laparotomic splenectomy following chronic thrombocytopenia and concurrent splenomegaly who subsequently developed extensive portal and splenic vein thrombosis. Teaching Point: Portal and splenic vein thrombosis after splenectomy is a relatively uncommon but important diagnosis in which radiology has a pivotal role.

Cervical Interspinous Ligament Sprain in a 6-Year-Old Boy.

Paediatric cervical spine trauma, though rare, is difficult to detect as the injuries are often soft-tissue injuries and thus not visible using conventional radiography. A 6-and-a-half-year-old child presented with neck pain following a fall. A thorough radiological workup over several days demonstrated soft-tissue injuries, undetected by initial cervical X-rays, requiring MRI to definitively prove. The patient recovered with conservative treatment. Teaching Point: Paediatric cervical spine injuries often present with soft tissue injuries, which can missed on X-rays and require further imaging to detect.

Pulmonary Artery Vasoconstriction Due to Bronchial Obstruction.

Pulmonary artery (PA) vasoconstriction resulting from pulmonary ventilation/perfusion imbalance is infrequently detected with computed tomography (CT). An 85-year-old woman presented to the emergency room with dyspnea and desaturation, despite oxygen supply. A CT pulmonary angiography (CTPA) revealed massive central bronchial mucoid impaction in all but the right upper bronchus. Only the right upper pulmonary veins were opacified, which we speculate was linked to the central bronchial obstruction, with identical distributions, through vasoconstriction of the corresponding PAs. Teaching Point: This case demonstrates the unusual imagery-physiology correlation of pulmonary artery vasoconstriction that cannot normally be detected by CTPA.

The contribution of ultrasound for the differential diagnosis of congenital and infantile nephrotic syndrome.

The aim of this study was to determine whether high-resolution ultrasound is able to differentiate between the various diseases associated with nephrotic syndrome (NS). We reviewed the US features of 15 patients less than 1 year presenting a NS whose exact type was defined by pathology nephrotic syndrome of Finnish type (NSFT, n=2); focal and segmental hyalinosis (FSH, n=3); minimal-change glomerular disease (MCGD, n=2); neonatal glomerulonephritis (n=1), and diffuse mesangial sclerosis (DMS, n=7). The US features studied included the size of the kidneys, cortical echogenicity, cortico-medullary differentiation (CMD), and borders. The images were reviewed on hard copies by two observers unaware of the final diagnosis. In each case a diagnosis was proposed based on the reading of the US features. Six patients with DMS displayed a peculiar US pattern: mild increase of renal size; and inhomogeneous (patchwork-like) parenchymal hyperechogenicity that included areas of the cortex and medulla. The NSFT and neonatal glomerulonephritis displayed some of the same US features: increased kidney size (+2 SD) and had homogeneous cortical hyperechogenity with persistent cortico-medullar differentiation. The kidneys in the 3 patients with SFH were sonographically normal (n=1) or displayed a mild cortical hyperechogenicity (n=2). Inhomogeneous parenchymal hyperechogenicity involving only segments of the cortex and medulla seems to be a specific US pattern for DMS. Ultrasound is less specific for the other types of CNS.