Mats Lidén

Background: Interreader variability in ureteral stone size measurements affect the predicted probability of spontaneous stone passage (SSP), especially in proximal ureteral stones. Window settings have been shown to influence interreader variability. Purpose: To investigate interreader variability of ureteral stone size measurements in four different window settings. Material and Methods: Patients with a unilateral proximal ureteral stone ≥2.0 mm detected during emergency computed tomography (CT) were included in this single-center study. Five observers measured each stone in three dimensions in a soft-tissue window, bone window, and two half-value windows (based on the mean [half-value MEAN] or maximum attenuation of the stone [half-value MAX]). Limits of agreement of the mean (LOAM) for stone size in each window setting were assessed. Logistic regression curves were created for predicted probability of SSP. Results: In total, 124 patients (87 men, 37 women; mean age = 52 years; age range = 22–82 years) were retrospectively evaluated. LOAM: bone window (±1.6 mm, 95% confidence interval [CI]=1.24–4.90), soft-tissue window (±0.4 mm, 95% CI=0.37–0.82), half-value MEAN window (±0.3 mm, 95% CI=0.24–0.40), half-value MAX window (±0.2 mm, 95% CI=0.14–0.30). Prediction curves aligned and shifted to the left as mean stone size decreased in the half-value window settings. Conclusion: The bone window is unsatisfactory for ureteral stone size measurements. The interreader variability in soft-tissue and half-value windows is on a sub-mm magnitude, with no expected impact on clinical decision-making. The half-value MAX window had the smallest interreader variability and should be considered for reproducible and semiautomated ureteral stone size measurements.

This work aims to evaluate whether radiological signs of stone impaction (RSSI) measured on non-contrast computed tomography (CT) can predict shock wave lithotripsy (SWL) outcomes for upper ureteral stones and to assess whether integrating these markers into an existing prediction model (the Niwa nomogram) improves predictive performance. We retrospectively analysed 256 patients treated with SWL for upper ureteral stones between 2012 and 2019. Standard stone parameters and RSSI, including ureteral wall thickness (UWT), ureteral diameters and CT attenuations above and below the stone, were assessed. Multivariable logistic regression, receiver operating characteristic (ROC) analysis, net reclassification improvement (NRI) and decision curve analysis (DCA) were used to evaluate predictive performance. The Niwa nomogram was enhanced by incorporating significant RSSI parameters and was internally validated using k -fold cross-validation. Maximum ureteral attenuation below the stone (UABSmax), ureter diameter above the stone (UDAS) and renal pelvis diameter (RPD) were found to be associated with SWL outcome. UABSmax had the highest individual predictive value (area under the curve (AUC) 0.66), while UWT showed no significant association or predictive value. Incorporating UABSmax and RPD into the Niwa nomogram (Niwa+) marginally increased AUC (0.72 vs. 0.71) but did not lead to significant improvements in NRI or DCA. In conclusion, certain RSSI– particularly UABSmax and RPD– were associated with SWL outcome but provided limited value when added to an already validated nomogram.

Stone size and location are key factors in predicting spontaneous stone passage (SSP), but little attention has been paid to the influence of radiological signs of stone impaction (RSSI). This research aims to determine whether RSSI, alongside stone size, can predict SSP and to evaluate the consistency of ureteral wall thickness (UWT) measurements among observers. In this retrospective study, 160 patients with a single upper or middle ureteral stone on acute non-enhanced computed tomography (NCCT) were analysed. Patient data were collected from medical records. Measurements of RSSI, including UWT, ureteral diameters, and average attenuation above and below the stone, were taken on NCCT by four independent readers blind to the outcomes. The cohort consisted of 70% males with an average age of 51 ± 15. SSP occurred in 61% of patients over 20 weeks. The median stone length was 5.7 mm (IQR: 4.5–7.3) and was significantly shorter in patients who passed their stones at short- (4.6 vs. 7.1, p < 0.001) and long-term (4.8 vs. 7.1, p < 0.001) follow-up. For stone length, the area under the receiver operating characteristic curve (AUC) for predicting SSP was 0.90 (CI 0.84–0.96) and only increased to 0.91 (CI 0.85–0.95) when adding ureteral diameters and UWT. Ureteral attenuation did not predict SSP (AUC < 0.5). Interobserver variability for UWT was moderate, with ± 2.0 mm multi-reader limits of agreement (LOA). The results suggest that RSSI do not enhance the predictive value of stone size for SSP. UWT measurements exhibit moderate reliability with significant interobserver variability.

Objective: The aim of the study was to study infection, hospitalization, and admission to intensive care unit for COVID-19 in different occupations and pandemic waves in a Swedish county. Methods: Individual registry data of infection and hospitalization were merged with occupational data in this cross-sectional study. Infected, hospital-, and intensive care unit-admission were analyzed by occupational groups. Results: 22,095 cases of COVID-19 from 21 February 2020 to 31 August 2022 were identified. Healthcare workers and others working in close physical proximity showed a higher rate of confirmed COVID-19 infections in all waves and higher risk for hospital admission early in the pandemic. Exposure to diseases and physical proximity played a decisive role. Conclusions: Workers in close-contact occupations experienced a higher rate of confirmed infections throughout the pandemic and higher hospitalization rates in the first pandemic wave, suggesting a need for more effective initial safety measures in a future pandemic.

Objectives: Quantitative CT imaging is an important emphysema biomarker, especially in smoking cohorts, but does not always correlate to radiologists’ visual CT assessments. The objectives were to develop and validate a neural network-based slice-wise whole-lung emphysema score (SWES) for chest CT, to validate SWES on unseen CT data, and to compare SWES with a conventional quantitative CT method. Materials and methods: Separate cohorts were used for algorithm development and validation. For validation, thin-slice CT stacks from 474 participants in the prospective cross-sectional Swedish CArdioPulmonary bioImage Study (SCAPIS) were included, 395 randomly selected and 79 from an emphysema cohort. Spirometry (FEV1/FVC) and radiologists’ visual emphysema scores (sum-visual) obtained at inclusion in SCAPIS were used as reference tests. SWES was compared with a commercially available quantitative emphysema scoring method (LAV950) using Pearson’s correlation coefficients and receiver operating characteristics (ROC) analysis. Results: SWES correlated more strongly with the visual scores than LAV950 (r = 0.78 vs. r = 0.41, p < 0.001). The area under the ROC curve for the prediction of airway obstruction was larger for SWES than for LAV950 (0.76 vs. 0.61, p = 0.007). SWES correlated more strongly with FEV1/FVC than either LAV950 or sum-visual in the full cohort (r = − 0.69 vs. r = − 0.49/r = − 0.64, p < 0.001/p = 0.007), in the emphysema cohort (r = − 0.77 vs. r = − 0.69/r = − 0.65, p = 0.03/p = 0.002), and in the random sample (r = − 0.39 vs. r = − 0.26/r = − 0.25, p = 0.001/p = 0.007). Conclusion: The slice-wise whole-lung emphysema score (SWES) correlates better than LAV950 with radiologists’ visual emphysema scores and correlates better with airway obstruction than do LAV950 and radiologists’ visual scores. Clinical relevance statement: The slice-wise whole-lung emphysema score provides quantitative emphysema information for CT imaging that avoids the disadvantages of threshold-based scores and is correlated more strongly with reference tests than LAV950 and reader visual scores. Key Points: • A slice-wise whole-lung emphysema score (SWES) was developed to quantify emphysema in chest CT images. • SWES identified visual emphysema and spirometric airflow limitation significantly better than threshold-based score (LAV950). • SWES improved emphysema quantification in CT images, which is especially useful in large-scale research.

COVID-19 has a most variable prognosis. Several risk factors for an unfavourable outcome have been identified including extensive lung involvement on chest CT and high viral load estimated by RT-PC...

Chest CT is prognostic in Covid-19 but there is a lack of consensus on how to report the CT findings. A chest CT scoring system, ÖCoS, was implemented in clinical routine on 1 April 2020, in Örebro...