SARS-CoV-2 coinfection in children with severe airway obstruction due to pulmonary tuberculosis.

INTRODUCTION: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic had a significant impact on tuberculosis (TB) control globally, with the number of new TB diagnoses decreasing. Coinfection with some viruses, especially measles, could aggravate TB in children. This is presumably a result of depressed cellular immunity. Reports on children with TB and SARS-CoV-2 coinfection are limited. METHODS: A retrospective analysis of children up to 13 years old admitted to Tygerberg Hospital, Cape Town, South Africa, from March 2020 to December 2022 with suspected TB-induced airway compression requiring bronchoscopy. Children were included if they presented with severe intrathoracic airway obstruction and/or radiographic evidence of complicated TB. The patients were divided into two groups based on SARS-CoV-2 respiratory polymerase chain reaction results. Demographics, TB exposure, microbiology, SARS-CoV-2 laboratory data, imaging, inflammatory cytokine levels, and bronchoscopy data were collected. Statistical analyses compared SARS-CoV-2 positive and negative groups. RESULTS: Of the 50 children undergoing bronchoscopy for TB airway obstruction, 7 (14%) were SARS-CoV-2 positive. Cough was more prevalent in the SARS-CoV-2 positive group (p = 0.04). There was no difference in TB culture yield between groups. However, SARS-CoV-2 positive children showed slower radiological improvement at 1 month (p = 0.01), pleural effusions (p < 0.001), and a higher need for endoscopic enucleation (p < 0.001). FDG PET/CT scans indicated an ongoing inflammation in the SARS-CoV-2 positive group. CONCLUSIONS: Coinfection with SARS-CoV-2 in children with TB airway obstruction appears to complicate the disease course, necessitating more medical interventions and demonstrating a longer duration of the TB inflammatory process. Further research is needed to understand the impact of viral infections on TB progression and outcomes in pediatric patients.

Dual energy window imaging for optimisation of P/V ratios in VP SPECT.

PURPOSE: Ventilation-perfusion single-photon emission computed tomography (VP SPECT) plays an important role in pulmonary embolism diagnosis. Rapid results may be obtained using same-day ventilation followed by perfusion imaging, but generally requires careful attention to achieving an optimal count rate ratio (P/V ratio) of ≥ 3:1. This study investigated whether the ratio of counts simultaneously acquired in adjacent primary and Compton scatter energy windows (Eratio) on V SPECT was predictive of final normalised perfusion count rate (PCRnorm) on P SPECT using [99mTc]Tc-macroaggregated albumin (MAA), thus allowing for optimisation of P/V ratios. METHODS: Same-day VP SPECT studies acquired using standard protocols in adult patients during a 2-year period (training dataset) were assessed. Studies were included provided they were acquired with correct imaging parameters, and injection site imaging and laboratory records were available for quality control and normalised count rate corrections. Extraction of DICOM information, and linear regression were performed using custom Python and R scripts. A predictive tool was developed in Microsoft Excel. This tool was then validated using a second (validation) dataset of same-day studies acquired over a subsequent 7-month period. Accuracy of the prediction tool was assessed by calculating the mean absolute percentage error (MAPE). RESULTS: Of 643 studies performed, the scans of 342 participants (median age 30.4 years, 318 female) were included in the training dataset, the analysis of which yielded a significant regression equation (F(1,340) = 1057.3, p < 0.0001), with an adjusted R2 of 0.756 and MSE of 0.001089. A prediction tool designed for routine clinical use was developed for predicting final P/V ratio. Of an additional 285 studies, 198 were included in the second (validation) dataset (median age 29.7 years, 188 female). The Excel-based tool was shown to be 91% accurate (MAPE: 9%) in predicting P/V ratio. CONCLUSION: The relationship between the ratio of simultaneously acquired counts in adjacent energy windows on V SPECT and perfusion count rate after administration of a known activity of [99mTc]Tc-MAA can be linearly approximated. A predictive tool based on this work may assist in optimising the dose and timing of [99mTc]Tc-MAA administration in same-day studies to the benefit of patients and workflows.

Syphilitic pancreatitis: A rare mimicker of our time.

We present an unusual case of syphilitic pancreatitis and ascending aortitis in a 41-year-old HIV-negative male patient presenting to a tertiary institution with obstructive jaundice. After a battery of investigations that included computed tomography (CT) and 18F-labelled fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) imaging, syphilis serology and histology, a diagnosis of tertiary syphilis was made. The patient responded favourably to antibiotics, with resolution of all lesions on FDG PET/CT 13 weeks after initiation of therapy. Even though tertiary syphilis is a rare entity, it should be earmarked as a mimicker of other pathological conditions, including, in this case, primary pancreatic malignancy.