Repeatability, and Intra-Observer and Interobserver Agreement of Two Dimensional Perfusion Angiography in Patients with Chronic Limb Threatening Ischaemia

Abstract

Objective: Two dimensional (2D) perfusion angiography is a method that provides quantitative foot perfusion information from standard digital subtraction angiography acquisitions. The aim of this study was to test the reliability of this method in patients with chronic limb threatening ischaemia (CLTI) by investigating repeatability, and intra-observer and interobserver agreement.

Methods: Twenty patients with CLTI and a below the knee endovascular revascularisation were included in a prospective clinical study. Prior to treatment two perfusion angiography runs were acquired with a five minute interval without performing an intervention. In these recordings, regions of interest were selected and time density curves and perfusion parameters were determined. To investigate intra-observer agreement one observer performed five measurements on the same acquisition for each patient. To investigate interobserver agreement three observers performed measurements on the same acquisition for each patient. Results were presented in Bland-Altman plots and as the intraclass correlation coefficient per parameter.

Results: Two patients were excluded from repeatability analyses because of major motion artefacts. Repeatability analyses of the 18 remaining patients showed excellent correlation for every parameter (> .96). Intra-observer and interobserver agreement for all 20 patients were excellent for all parameters (1.00).

Conclusion: Repeatability and intra-observer and interobserver agreement of 2D perfusion angiography in patients with CLTI were found to be excellent. It is therefore a reliable tool when used according to the standardised methods described in this study.

Keywords: 2D perfusion angiography; Chronic limb threatening ischemia; Interobserver agreement; Intra-observer agreement; Repeatability.