On replacing the manual measurement of ACR phantom images performed by MRI technologists with an automated measurement approach.

ABSTRACT

PURPOSE: To assess whether measurements on American College of Radiology (ACR) phantom images performed by magnetic resonance imaging (MRI) technologists as part of a weekly quality control (QC) program could be performed exclusively using an automated system without compromising the integrity of the QC program. MATERIALS AND METHODS: ACR phantom images are acquired on 15 MRI scanners at a number of ACR-accredited sites to fulfill requirements of a weekly QC program. MRI technologists routinely perform several measurements on these images. Software routines are also used to perform the measurements. A set of geometry measurements made by technologists over a five week period and those made using software routines were compared to reference-standard measurements made by two MRI physicists. RESULTS: The geometry measurements performed by software routines had a very high positive correlation (0.92) with the reference-standard measurements. Technologist measurements also had a high positive correlation (0.63), although the correlation was less than for the automated measurements. Bland-Altman analysis revealed overall good agreement between the automated and reference-standard measurements, with the 95% limits of agreement being within ±0.62 mm. Agreement between the technologist and the reference-standard measurements was demonstratively poorer, with 95% limits of agreement being ±1.46 mm. Some of the technologist measurements differed from the reference standard by as much as 2 mm. CONCLUSION: The technologists' geometry measurements may be able to be replaced by automated measurement without compromising the weekly QC program required by the ACR.