Influenza A (H1N1) pneumonia: HRCT findings

Abstract

OBJECTIVE: To describe aspects found on HRCT scans of the chest in patients infected with the influenza A (H1N1) virus. METHODS: We retrospectively analyzed the HRCT scans of 71 patients (38 females and 33 males) with H1N1 infection, confirmed through laboratory tests, between July and September of 2009. The HRCT scans were interpreted by two thoracic radiologists independently, and in case of disagreement, the decisions were made by consensus. RESULTS: The most common HRCT findings were ground-glass opacities (85%), consolidation (64%), or a combination of ground-glass opacities and consolidation (58%). Other findings were airspace nodules (25%), bronchial wall thickening (25%), interlobular septal thickening (21%), crazy-paving pattern (15%), perilobular pattern (3%), and air trapping (3%). The findings were frequently bilateral (89%), with a random distribution (68%). Pleural effusion, when observed, was typically minimal. No lymphadenopathy was identified. CONCLUSIONS: The most common findings were ground-glass opacities and consolidations, or a combination of both. Involvement was commonly bilateral with no axial or craniocaudal predominance in the distribution. Although the major tomographic findings in H1N1 infection are nonspecific, it is important to recognize such findings in order to include infection with the H1N1 virus in the differential diagnosis of respiratory symptoms.

Primary A (H1N1) pdm09 Influenza Pneumonia Diagnosed on Reverse Transcription-polymerase Chain Reaction (RT-PCR) of Bronchoalveolar Lavage Fluid but not Rapid Tests with Nasopharyngeal Swabs

“…The findings of ground glass opacity, a crazy-paving pattern and consolidation in the bilateral lung fields on CT observed in the present case are consistent with those of primary viral pneumonia reported previously (6). However, these findings on CT are not specific to A (H1N1) pdm09 influenza viral pneumonia.…”

Clinical and laboratory findings of patients with the possible diagnosis of influenza hospitalized in affiliated hospitals of Babol University of Medical Sciences, 2015-2016

“…An interesting point was the prevalence (25.2%) of gastrointestinal symptoms in patients. This was also found in other similar studies of H1N1 influenza [18,19]. This last is, therefore, a good guide for the timely diagnosis of influenza patients who are referred with gastrointestinal manifestations.…”

Fatal H7N9 pneumonia complicated by viral infection of a prosthetic cardiac valve – An autopsy study

“…Our patient was treated with intravenous NAI while the cases that had numerous positive cells were only treated with oral oseltamivir, which may have impaired drug distribution in seriously ill patients. Thirdly, in our patient and the previously reported Hong Kong cases there was evidence of pleural involvement and this has been a feature of H7N9 influenza [3,12], in contrast to infections with H1N1 where pleural effusions were rarely documented [13]. The unique finding is this case is the presence of a thrombus over the prosthetic valve in which viral antigen was detected.…”