COVID-19 vaccine-induced lymphadenopathies: incidence, course and imaging features from an ultrasound prospective study.

AIMS: lymphadenopathy can occur after COVID-19 vaccination and when encountered at ultrasound examinations performed for other reasons might pose a diagnostic challenge. Purpose of the study was to evaluate the incidence, course and ultrasound imaging features of vaccine-induced lymphadenopathy. METHODS: 89 healthy volunteers (median age 30, 76 females) were prospectively enrolled. Vaccine-related clinical side effects (e.g., fever, fatigue, palpable or painful lymphadenopathy) were recorded. Participants underwent bilateral axillary, supraclavicular and cervical lymph node stations ultrasound 1-4 weeks after the second dose and then again after 4-12 weeks in those who showed lymphadenopathy at the first ultrasound. B-mode, color-Doppler assessment, and shear-wave elastography (SWE) evaluation were performed. The correlation between lymphadenopathy and vaccine-related side effects was assessed using the Fisher's exact test. RESULTS: Post-vaccine lymphadenopathy were found in 69/89 (78%) participants (37 single and 32 multiple lymphadenopathy). Among them, 60 presented vaccine-related side effects, but no statistically significant difference was observed between post-vaccine side effect and lymphadenopathy. Ultrasound features of vaccine-related lymphadenopathy consisted of absence of fatty hilum, round shape and diffuse or asymmetric cortical thickness (median cortical thickness of 5 mm). Vascular signal was mainly found to be increased, localized in both central and peripheral regions. SWE showed a soft cortical consistence in all cases (median value 11 Kpa). At follow-up, lymph-node morphology was completely restored in most cases (54/69, 78%) and in no case lymphadenopathy had worsened. CONCLUSION: A high incidence of vaccine-induced lymphadenopathy was found in a population of healthy subjects, with nearly complete regression within 4-12 weeks.

Impact of COVID-19 pandemic on 2-[18F]FDG PET/CT imaging work-flow in a single medical institution: comparison among the three Italian waves.

PURPOSE: To compare the impact of COVID-19 pandemic on 2-[18F]FDG PET/CT imaging work-flow during the three waves in a medical institution of southern of Italy. METHODS: We retrospectively reviewed the numbers and results of 2-[18F]FDG PET/CT studies acquired during the following three periods of the COVID-19 waves: 1) February 3-April 30, 2020; 2) October 15, 2020-January 15, 2021; and 3) January 18-April 16, 2021. RESULTS: A total of 861 PET/CT studies in 725 patients (388 men, mean age 64 ± 4 years) was acquired during the three waves of COVID-19 pandemic. The majority (94%) was performed for diagnosis/staging (n = 300) or follow-up (n = 512) of neoplastic diseases. The remaining 49 studies (6%) were acquired for non-oncological patients. The distribution of number and type of clinical indications for PET/CT studies in the three waves were comparable (p = 0.06). Conversely, the occurrence of patients positive for COVID-19 infection progressively increased (p < 0.0001) from the first to third wave; in particular, patients with COVID-19 had active infection before PET/CT study as confirmed by molecular oro/nasopharyngeal swab. CONCLUSION: Despite the restrictive medical measures for the emergency, the number of 2-[18F]FDG PET/CT studies was unchanged during the three waves guaranteeing the diagnostic performance of PET/CT imaging for oncological patients.

Ultrasound and shear-wave elastography patterns of COVID-19 mRNA vaccine-related axillary, supra and subclavicular lymphadenopathy.

In this pictorial essay, we illustrate the ultrasound appearance of COVID-19 Pfizer-BioNTech vaccine-related lymph node abnormalities, which can occur at different stations ipsilateral to the site of vaccination, after either first or second vaccine dose and can represent a diagnostic dilemma when encountered in patients with underlying conditions. Typically, they appear as enlarged hypoechoic nodes with loss of fat hilum, increased hilar and cortical vascularization at color-Doppler, but low to intermediate cortical consistence at shear-wave elastography. Asymmetric or diffuse cortical thickening is also frequently encountered. They can be observed in patients without and with clinical symptoms, such as armpit pain, fever and fatigue.

Chest CT in COVID-19 patients: Structured vs conventional reporting.

PURPOSE: To assess clinician satisfaction with structured (SR) and conventional (CR) radiological reports for chest CT exams in coronavirus disease 2019 (COVID-19) patients, objectively comparing both reporting strategies. METHOD: We retrospectively included 68 CTs (61 patients) with COVID-19. CRs were collected from the digital database while corresponding SRs were written by an expert radiologist, including a sign checklist, severity score index and final impressions. New CRs were prepared for a random subset (n = 10) of cases, to allow comparisons in reporting time and word count. CRs were analyzed to record severity score and final impressions inclusion. A random subset of 40 paired CRs and SRs was evaluated by two clinicians to assess, using a Likert scale, readability, comprehensiveness, comprehensibility, conciseness, clinical impact, and overall quality. RESULTS: Overall, 19/68 (28 %) and 9/68 (13 %) of CRs included final impressions and severity score, respectively. SR writing required significantly (p < 0.001) less time (mean = 308 s; SD ± 60 s) compared to CRs (mean = 458 s; SD ± 72 s). On the other hand, word count was not significantly different (p = 0.059, median = 100 and 106, range = 106-139 and 88-131 for SRs and CRs, respectively). Both clinicians expressed significantly (all p < 0.01) higher scores for SRs compared to CRs in all categories. CONCLUSIONS: Our study supports the use of chest CT SRs in COVID-19 patients to improve referring physician satisfaction, optimizing reporting time and provide a greater amount and quality of information within the report.