Added value of hyperdense lumen sign in prediction of acute central and peripheral pulmonary embolism on non-contrast CT chest

COVID-19 on Chest CT: Translating Known Microscopic Findings to Imaging Observations

Purpose: To describe the imaging findings of COVID-19 and correlate them with their known pathology observations. Methods: This is an IRB-approved retrospective study performed at Columbia University Irving Medical Center (IRB # AAAS9652) that included symptomatic adult patients (21 years or older) who presented to our emergency room and tested positive for COVID-19 and were either admitted or discharged with at least one chest CT from 11 March 2020 through 1 July 2020. CT scans were ordered by the physicians caring for the patients; our COVID-19 care protocols did not specify the timing for chest CT scans. A scoring system was used to document the extent of pulmonary involvement. The total CT grade was the sum of the individual lobar grades and ranged from 0 (no involvement) to 16 (maximum involvement). The distribution of lung abnormalities was described as peripheral (involving the outer one-third of the lung), central (inner two-thirds of the lung), or both. Additional CT findings, including the presence of pleural fluid, atelectasis, fibrosis, cysts, and pneumothorax, were recorded. Contrast-enhanced CT scans were evaluated for the presence of a pulmonary embolism, while non-contrast chest CT scans were evaluated for hyperdense vessels. Results: 209 patients with 232 CT scans met the inclusion criteria. The average age was 61 years (range 23–97 years), and 56% of the patients were male. The average score reflecting the extent of the disease on the CT was 10.2 (out of a potential grade of 16). Further, 73% of the patients received contrast, which allowed the identification of a pulmonary embolism in 21%. Of those without contrast, 33% had hyperdense vessels, which might suggest a chronic pulmonary embolism. Further, 47% had peripheral opacities and 9% had a Hampton’s hump, and 78% of the patients had central consolidation, while 28% had round consolidations. Atelectasis was, overall, infrequent at 5%. Fibrosis was observed in 11% of those studied, with 6% having cysts and 3% pneumothorax. Conclusions: The CT manifestations of COVID-19 can be divided into findings related to endothelial and epithelial injury, as were seen on prior post-mortem reports. Endothelial injury may benefit from treatments to stabilize the endothelium. Epithelial injury is more prone to developing pulmonary fibrotic changes.

Side Effects of Oncologic Treatment in the Chest: Manifestations at FDG PET/CT

Fluorodeoxyglucose (FDG) PET/CT is a vital imaging technique used for staging, assessing treatment response, and restaging following completion of therapy in patients who are undergoing or have completed oncologic treatment. A variety of adverse effects from chemotherapy, targeted therapy, immunotherapy, and radiation therapy are commonly encountered in oncologic patients. It is important to be aware of the manifestations of these adverse effects seen on FDG PET/CT images to avoid misinterpreting these findings as disease progression. Furthermore, early identification of these complications is important, as it may significantly affect patient management and even lead to a change in treatment strategy. The authors focus on the FDG PET/CT manifestations of a broad spectrum of oncologic therapy-related adverse effects in the thorax, as well as some treatment-related changes that may potentially mimic malignancy. Online supplemental material is available for this article. ^©RSNA, 2021.