Related Experiment Videos
Vessel size measurements in angiograms: manual measurements
Kenneth R Hoffmann1, Jacek Dmochowski, Daryl P Nazareth
1Department of Neurosurgery, Toshiba Stroke Research Center, University at Buffalo, Buffalo, New York 14214-3025, USA. kh9@acsu.buffalo.edu
Insights
Manual vessel size measurements in angiography show accuracy comparable to automated methods for vessels larger than 1 mm. However, for smaller vessels, automated techniques considering resolution are recommended for precise measurements.
Area of Science:
- Medical Imaging
- Radiology
- Quantitative Analysis
Background:
- Vessel size measurement is crucial in diagnostic and interventional angiography.
- Clinicians often prefer manual measurements over automated techniques despite the latter's perceived accuracy.
Purpose of the Study:
- To investigate the accuracy and precision of manual vessel size measurements.
- To compare manual versus automated techniques for vessel sizing.
Main Methods:
- Manual measurements of vessel sizes were performed by neuroradiologists and physicists.
- Studies included simulations with varying resolution functions and phantom studies with different image intensifier modes and zoom levels.
Main Results:
- Manual measurements demonstrated accuracy and reproducibility ranging from 0.1 to 0.2 mm.
- Accuracy was comparable to automated techniques for vessels larger than 1 mm.
- Automated techniques are superior for vessels smaller than 1 mm, especially when accounting for resolution functions.
Conclusions:
- Manual vessel sizing is reliable for larger vessels (>1 mm) in angiography.
- Automated vessel sizing methods that incorporate resolution functions are essential for accurate measurements of smaller vessels (<1 mm).
Abstract:
Vessel size measurement is perhaps the most often performed quantitative analysis in diagnostic and interventional angiography. Although automated vessel sizing techniques are generally considered to have good accuracy and precision, we have observed that clinicians rarely use these techniques in standard clinical practice, choosing to indicate the edges of vessels and catheters to determine sizes and calibrate magnifications, i.e., manual measurements. Thus, we undertook an investigation of the accuracy and precision of vessel sizes calculated from manually indicated edges of vessels. Manual measurements were performed by three neuroradiologists and three physicists. Vessel sizes ranged from 0.1-3.0 mm in simulation studies and 0.3-6.4 mm in phantom studies. Simulation resolution functions had full-widths-at-half-maximum (FWHM) ranging from 0.0 to 0.5 mm. Phantom studies were performed with 4.5 in., 6 in., 9 in., and 12 in. image intensifier modes, magnification factor = 1, with and without zooming. The accuracy and reproducibility of the measurements ranged from 0.1 to 0.2 mm, depending on vessel size, resolution, and pixel size, and zoom. These results indicate that manual measurements may have accuracies comparable to automated techniques for vessels with sizes greater than 1 mm, but that automated techniques which take into account the resolution function should be used for vessels with sizes smaller than 1 mm.