Geometric 3D analyses of the foot and ankle using weight-bearing and non weight-bearing cone-beam CT images: The new standard?

OBJECTIVES: We hypothesize that three-dimensional (3D) geometric analyses in weight bearing CT-images of the foot and ankle are more reproducible compared to two-dimensional (2D) analyses. Therefore, we compared 2D and 3D analyses on bones of weight-bearing and non weight-bearing cone-beam CT images of healthy volunteers. METHODS: Twenty healthy volunteers (10 male, 10 female, mean age 37.5 years) underwent weight-bearing and non weight-bearing cone-beam CT imaging of both feet. Clinically relevant height and angle measurements were performed in 2D and 3D (for example: cuboid height, calcaneal pitch, talo-calcaneal angle, Meary's angle, intermetatarsal angle). Three-dimensional measurements were obtained using automated software. Intra-observer and inter-observer agreement were evaluated for all 2D measurements. RESULTS: Overall intraclass correlation coefficients (ICC's) were higher than 0.750 for most 2D measurements, ranging from 0.352 to 0.995. Calcaneal pitch, angle between the first metatarsal (MT1) and proximal phalange 1, between the fifth metatarsal (MT5) and the calcaneus and heights of the sesamoid bones, navicular, cuboid and talus decreased during weight-bearing in both 2D and 3D results (p < 0.01). Meary's angle was not statistically different in 2D (p = 0.627) and 3D (p = 0.765). Higher coefficients of variation in 2D geometric analysis parameters (0.27 versus 0.16) indicate that 3D analyses are more precise compared to 2D (p < 0.01). Results of left and right feet are comparable for 2D and 3D analyses. CONCLUSION: Although 2D and 3D geometrical analyses are fundamentally different, automated 3D analyses are more reproducible and precise compared to 2D analyses. In addition, 3D evaluation better demonstrates differences in bone configurations between weight-bearing and non weight-bearing conditions, which may be of value to demonstrate pathology.

Men and women affected by Sars-CoV-2 pneumonia: same CT features but different outcome.

AIM: To compare the computed tomography (CT) features of Sars-CoV-2 pneumonia between the two sexes and among different age groups. MATERIALS AND METHODS: Consecutive patients (n=331) who presented to the emergency department and underwent chest CT and reverse transcription polymerase chain reaction (RT-PCR) with a time interval <7 days, which were subsequently found to be consistent with Sars-CoV-2 infection, were enrolled retrospectively. Two experienced radiologists evaluated the images in consensus, recording the number of pulmonary lobes with ground-glass opacities and with consolidation. A CT score was subsequently calculated based on the percentage involvement of each lobe. Clinical symptoms, comorbidities, and level of required hospitalisation were noted. In-hospital mortality was recorded and analysed via the Kaplan-Meier estimator. RESULTS: Males and females had the same age distribution. No statistically significant difference was found in the analysed CT features and in the CT score (p=0.31) between the sexes. More females were affected by two or more comorbidities (17.1% versus 7.5%, p=0.024), all comorbidities except diabetes were more prevalent in females. Women had a higher probability to be discharged home and a lower probability to be admitted to the intensive care unit (ICU; p=0.008), in-hospital mortality was inferior (13.5% versus 22%). CONCLUSION: Despite more comorbidities, women had lower hospital admission and mortality, which was independent of CT findings between both sexes.