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Intra- and interobserver variability in the measurements of abdominal aortic and common iliac artery diameter with
K Singh1, B K Jacobsen, S Solberg
1Department of Radiology, University Hospital of North-Norway, Tromsø, 9038 Tromsø, Norway.
Insights
Interobserver variability in computed tomography (CT) measurements of aortic and common iliac artery diameter is significant, especially in patients with abdominal aortic aneurysms (AAA). This variability impacts clinical decisions and requires simultaneous review of previous CT scans.
Area of Science:
- Vascular imaging and radiology
- Medical diagnostics
- Quantitative medical imaging
Background:
- Accurate measurement of aortic and common iliac artery diameter is crucial for diagnosing and monitoring vascular conditions.
- Computed tomography (CT) is a common imaging modality for assessing these vessels.
- Understanding measurement variability is essential for reliable clinical interpretation.
Purpose of the Study:
- To evaluate the intra- and interobserver variability in measuring aortic and common iliac artery diameters using CT.
- To identify factors influencing measurement variability.
Main Methods:
- A reproducibility study design was employed.
- Three radiologists measured aortic and common iliac artery diameters on CT scans from 59 subjects (29 with and 30 without abdominal aortic aneurysms).
- Measurements were taken at five aortic levels and included both common iliac arteries.
Main Results:
- Intraobserver variability differed based on radiologist, measurement plane, and level.
- Interobserver variability was higher than intraobserver variability at all levels, particularly at the aortic bifurcation.
- Variability increased with larger vessel diameters and was greatest in patients with abdominal aortic aneurysms (AAA).
- 94% of intraobserver measurements for maximal infrarenal aortic diameter were within 2mm, compared to 82% for interobserver measurements.
Conclusions:
- Interobserver variability in CT measurements of aortic and common iliac artery diameter is substantial and must be considered in clinical decision-making.
- Simultaneous review of prior CT scans is recommended to mitigate interobserver variability when assessing changes in aortic diameter.
Objectives:
to assess intra- and interobserver variability in the measurement of aortic and common iliac artery diameter by means of computed tomography (CT).
Design:
reproducibility study.
Material And Methods:
three radiologists performed measurements of aortic diameter at five different levels and of both common iliac arteries with CT. Fifty-nine subjects were examined, 29 with and 30 without abdominal aortic aneurysms (AAA) as assessed by ultrasound.
Results:
intraobserver variability varied between radiologists, measurement plane (anterior-posterior vs transverse) and measurement level. The interobserver variability was markedly higher at the bifurcation than at the suprarenal level and higher than intraobserver variability for measurements at all levels. Both intraobserver and interobserver variability increased with increasing vessel diameter and were largest in patients with AAA. The absolute intraobserver difference of the maximal infrarenal aortic diameter was 2mm or less in 94% of intraobserver pairs. The corresponding interobserver difference was 82%.
Conclusions:
interobserver variability of CT measurements of aortic and common iliac artery diameter is not negligible and should be taken into account when making clinical decisions. When assessing change in aortic diameter, previous CT-scans should be reviewed simultaneously as a routine to exclude interobserver variability.
