Impact of Image Reconstruction Parameters on Abdominal Aortic Calcification Measurement Using Abdominal Computed Tomography.

BACKGROUND AND AIMS: Abdominal aortic calcification (AAC) is correlated with cardiovascular outcomes independent of traditional risk factors. Quantification of AAC on computed tomography (CT) has not been standardized. Reconstruction parameters have been shown to impact coronary calcium scores. The aim of our study was to assess the impact of abdominal CT reconstruction parameters, slice thickness (ST), and display field of view (DFOV) on AAC quantitative scoring on abdominal CT examinations. METHODS: We retrospectively measured AAC on noncontrast CT of 46 patients (mean age, 64.1 years; 35 males) using 5 different reconstruction protocols with a range of ST and DFOV: protocol A, 2.5 mm ST, 35 cm DFOV; protocol B, 2.5 mm ST, 50 cm DFOV; protocol C, 2.5 mm ST, 25 cm DFOV; protocol D, 5 mm ST, 35 cm DFOV; and protocol E: 0.625 mm ST, 35 cm DFOV. The AAC scores from each protocol were compared using concordance correlation coefficient and Bland-Altman agreement analyses. RESULTS: The AAC mean (SD) scores for each protocol were as follows: A, 2022 (2418); B, 2022 (2412); C, 1939 (2310); D, 2220 (2695); and E, 1862 (2234). The AAC mean score differences between protocols and reference protocol A were -0.47, 82.01, -198.94, and 160 for protocols B, C, D, and E, respectively, with differences between protocols C to E statistically significantly different (P < 0.05). The different protocols showed overall excellent correlation (concordance correlation coefficient, >0.9) between AAC scores. CONCLUSIONS: Slice thickness and DFOV can impact AAC score measurement. A description of reconstruction parameters is important to allow comparisons across different cohorts.

Value of computed tomography scores in complicated acute diverticulitis.

BACKGROUND: Diverticular disease remains one of the most common conditions in the western world. Up to 25% of patients with diverticular disease require hospitalization, 15-30% of those of which require surgical intervention. CT scoring systems have been proposed as means to drive assessment and stratify patients necessitating hospital intervention. To assess and correlate CT scoring systems with clinical and surgical outcomes. METHODS: Retrospective cohort analysis at a single institution. Single institutional assessment with patients presenting to emergency with a CT diagnosed episode of acute diverticulitis. One hundred and eighty-nine patients were included in the study, 61% of which were male. Patient demographics, comorbidities, medications, biochemistry and inflammatory markers, type of complication following acute diverticulitis, operative/procedural intervention, hospital outcome and mortality were measured. CT scoring systems assessed included modified Hinchey, modified Neff, World Society of Emergency Surgery (WSES) and modified Siewert scoring systems. RESULTS: Majority of patients had left-sided diverticulitis (91%) with localized air (88%) and pericolic abscess (49%) the most common radiological findings. 28% of patients required radiological and/or surgical management with 12% requiring intensive care unit (ICU) admission. There was a general trend for surgical/radiological intervention as the scores increased in severity. The four scoring systems were found to be statistically significant predictors of any intervention and of ICU admission with minimal statistical differences across the different scoring systems. CONCLUSION: Radiological CT scores for complicated diverticulitis are at best, moderate predictors of clinical and surgical outcomes and may serve to guide management with minimal statistical differences across different scores.