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Objectives: To determine if identifiable hepatic textural features are present at abdominal CT in patients with colorectal cancer (CRC) prior to the development of CT-detectable hepatic metastases.Methods: Four filtration-histogram texture features (standard deviation, skewness, entropy and kurtosis) were extracted from the liver parenchyma on portal venous phase CT images at staging and post-treatment surveillance. Surveillance scans corresponded to the last scan prior to the development of CT-detectable CRC liver metastases in 29 patients (median time interval, 6 months), and these were compared with interval-matched surveillance scans in 60 CRC patients who did not develop liver metastases. Predictive models of liver metastasis-free survival and overall survival were built using regularised Cox proportional hazards regression.Results: Texture features did not significantly differ between cases and controls. For Cox models using all features as predictors, all coefficients were shrunk to zero, suggesting no association between any CT texture features and outcomes. Prognostic indices derived from entropy features at surveillance CT incorrectly classified patients into risk groups for future liver metastases (p < 0.001).Conclusions: On surveillance CT scans immediately prior to the development of CRC liver metastases, we found no evidence suggesting that changes in identifiable hepatic texture features were predictive of their development.Key Points: • No correlation between liver texture features and metastasis-free survival was observed. • Liver texture features incorrectly classified patients into risk groups for liver metastases. • Standardised texture analysis workflows need to be developed to improve research reproducibility. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to determine the prevalence of ischemic and alternative diagnoses and the diagnostic accuracy of CT angiography (CTA) in the setting of suspected acute mesenteric ischemia (AMI). Material and methods: We included 959 patients undergoing CTA for the evaluation of suspected AMI. The final clinical diagnosis was used to determine the prevalence of ischemic and alternative diagnoses and to calculate the diagnostic accuracy of CTA. Prevalence of diagnoses by age, sex, and admission status was compared using Cochran-Armitage and χ tests. Results: Prevalence was 18.8% (180/959) for AMI and 61.2% (587/959) for specific alternative diagnoses. In the remaining 20.0% (192/959), no clear clinical diagnosis was established. The most frequent alternative diagnoses were small-bowel obstruction (10.4%; 61/587), infectious colitis (8.7%; 51/587), pneumonia (6.5%; 38/587), cholecystitis (6.1%; 36/587), and diverticulitis (5.6%; 33/587). Prevalence of specific alternative diagnoses varied significantly according to both age ( p < .013) and admissions status ( p < 0.001). CTA had a sensitivity and specificity for diagnosing AMI of 89.4%/99.5% and for alternative diagnoses of 86.7%/96.9%, respectively. Conclusion: In the setting of suspected AMI, the prevalence of ischemic and alternative diagnoses varies significantly by age, sex, and admission status. CTA provides for rapid and non-invasive assessment of ischemic and alternative diagnoses with high diagnostic accuracy. [ABSTRACT FROM AUTHOR]

To validate a fully automated CT-based spinal trabecular bone mineral density (BMD) tool and apply it to a longitudinal screening cohort. The automated BMD tool was retrospectively applied to non-contrast abdominal CT scans in 1603 consecutive asymptomatic adults (mean age, 55.9 years; 770 M/833 F) undergoing longitudinal screening (mean interval, 5.7 years; range, 1.0–12.3 years). The spinal column was automatically segmented, with standardized L1 and L2 anterior trabecular ROI placement. Automated and manual L1 HU values were compared, as were automated supine-prone measures. L1-L2 CT attenuation values were converted to BMD values through a linear regression model. BMD values and changes were assessed according to age and gender. Success rate of the automated BMD tool was 99.8 % (four failed cases). Both automated supine vs prone and manual vs automated L1 attenuation measurements showed good agreement. Overall mean annual rate of bone loss was greater in females than males (–2.0% vs −1.0%), but the age-specific rate declined faster in females from age 50 (–2.1%) to age 65 (–0.3%) compared with males (–0.9% to −0.5%). Mean BMD was higher in females than males at age 50 (143.6 vs 135.1 mg cm–3), but post-menopausal bone loss in females reversed this relationship beyond age 60. By age 70, mean BMD in females and males was 100.8 and 107.7 mg cm–3 , respectively. This robust, fully automated CT BMD tool allows for both individualized and population-based assessment. Mean BMD was lower in men than women aged 50–60, but accelerated post-menopausal bone loss in women resulted in lower values beyond age 60. This fully automated tool can be applied to routine abdominal CT scans for prospective or retrospective opportunistic BMD assessment, including change over time. Mean BMD was lower in men compared with women aged 50–60 years, but accelerated bone loss in women during this early post-menopausal period resulted in lower BMD values for women beyond age 60. [ABSTRACT FROM AUTHOR]

To investigate a fully automated CT-based adiposity tool, applying it to a longitudinal adult screening cohort. A validated automated adipose tissue segmentation algorithm was applied to non-contrast abdominal CT scans in 8852 consecutive asymptomatic adults (mean age, 57.1 years; 3926 M/4926 F) undergoing colonography screening. The tool was also applied to follow-up CT scans in a subset of 1584 individuals undergoing longitudinal surveillance (mean interval, 5.6 years). Visceral and subcutaneous adipose tissue (VAT and SAT) volumes were segmented at levels T12-L5. Primary adipose results are reported herein for the L1 level as mean cross-sectional area. CT-based adipose measurements at initial CT and change over time were analyzed. Mean VAT values were significantly higher in males (205.8 ± 107.5 vs 108.1 ± 82.4 cm2; p < 0.001), whereas mean SAT values were significantly higher in females (171.3 ± 111.3 vs 124.3 ± 79.7 cm2; p < 0.001). The VAT/SAT ratio at L1 was three times higher in males (1.8 ± 0.7 vs 0.6 ± 0.4; p < 0.001). At longitudinal follow-up CT, mean VAT/SAT ratio change was positive in males, but negative in females. Among the 502 individuals where the VAT/SAT ratio increased at follow-up CT, 333 (66.3%) were males. Half of patients (49.6%; 786/1585) showed an interval increase in both VAT and SAT at follow-up CT. This robust, fully automated CT adiposity tool allows for both individualized and population-based assessment of visceral and subcutaneous abdominal fat. Such data could be automatically derived at abdominal CT regardless of the study indication, potentially allowing for opportunistic cardiovascular risk stratification. The CT-based adiposity tool described herein allows for fully automated measurement of visceral and subcutaneous abdominal fat, which can be used for assessing cardiovascular risk, metabolic syndrome, and for change over time. [ABSTRACT FROM AUTHOR]