Abstract
Objective: The purpose of this study was to construct a method of vessel edge detection that correctly identifies vessel pixels and to compare the interuser variability of cine phase contrast MR volumetric flow rates obtained with the conventional manual method and an automated method. Materials and Methods: The automated method was developed based on a magnitude image threshold value and compared with the manual method in a flow phantom (three users) and in velocity images of the portal vein (five users). The threshold value determined from the magnitude image was applied to a region of interest surrounding the vessel of interest on the magnitude image to construct a vessel edge detection mask m(x,y). The velocity images were then multiplied by the mask m(x,y) and volumetric flow rates determined using the identified vessel pixels. Results: In the flow phantom, flow measurements with the magnitude threshold method had significantly less interuser variability compared with the manual method (p < 0.01) and were within 10% (mean 6.0%) of the actual flow versus 35% (mean 18.6%) with the manual method. Regarding flow measurements in the portal vein of six volunteers, the magnitude threshold method was significantly more precise (p < 0.01) than the manual method with a mean standard deviation between the five users of 40.4 ± 12.9 ml/min (range 22-60 ml/min) and 110.4 ± 32.7 ml/min (range 70-155 ml/min), respectively. Conclusion: The magnitude threshold method of vessel edge detection developed in this study yields flow measurements that are accurate in the model system and have significantly less interuser variability than the manual method. This method shows promise for improving the precision of cine phase contrast flow measurements.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 469-475 |
| Number of pages | 7 |
| Journal | Journal of Computer Assisted Tomography |
| Volume | 18 |
| Issue number | 3 |
| State | Published - 1994 |
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Keywords
- Flow, measurements
- Magnetic resonance imaging, cine
- Magnetic resonance imaging, techniques
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Radiological and Ultrasound Technology
Cite this
Cine phase-contrast MR flow measurements : Improved precision using an automated method of vessel detection. / Burkart, D. J.; Felmlee, J. P.; Johnson, C. Daniel; Wolf, R. L.; Weaver, A. L.; Ehman, Richard Lorne.
In: Journal of Computer Assisted Tomography, Vol. 18, No. 3, 1994, p. 469-475.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cine phase-contrast MR flow measurements
T2 - Improved precision using an automated method of vessel detection
AU - Burkart, D. J.
AU - Felmlee, J. P.
AU - Johnson, C. Daniel
AU - Wolf, R. L.
AU - Weaver, A. L.
AU - Ehman, Richard Lorne
PY - 1994
Y1 - 1994
N2 - Objective: The purpose of this study was to construct a method of vessel edge detection that correctly identifies vessel pixels and to compare the interuser variability of cine phase contrast MR volumetric flow rates obtained with the conventional manual method and an automated method. Materials and Methods: The automated method was developed based on a magnitude image threshold value and compared with the manual method in a flow phantom (three users) and in velocity images of the portal vein (five users). The threshold value determined from the magnitude image was applied to a region of interest surrounding the vessel of interest on the magnitude image to construct a vessel edge detection mask m(x,y). The velocity images were then multiplied by the mask m(x,y) and volumetric flow rates determined using the identified vessel pixels. Results: In the flow phantom, flow measurements with the magnitude threshold method had significantly less interuser variability compared with the manual method (p < 0.01) and were within 10% (mean 6.0%) of the actual flow versus 35% (mean 18.6%) with the manual method. Regarding flow measurements in the portal vein of six volunteers, the magnitude threshold method was significantly more precise (p < 0.01) than the manual method with a mean standard deviation between the five users of 40.4 ± 12.9 ml/min (range 22-60 ml/min) and 110.4 ± 32.7 ml/min (range 70-155 ml/min), respectively. Conclusion: The magnitude threshold method of vessel edge detection developed in this study yields flow measurements that are accurate in the model system and have significantly less interuser variability than the manual method. This method shows promise for improving the precision of cine phase contrast flow measurements.
AB - Objective: The purpose of this study was to construct a method of vessel edge detection that correctly identifies vessel pixels and to compare the interuser variability of cine phase contrast MR volumetric flow rates obtained with the conventional manual method and an automated method. Materials and Methods: The automated method was developed based on a magnitude image threshold value and compared with the manual method in a flow phantom (three users) and in velocity images of the portal vein (five users). The threshold value determined from the magnitude image was applied to a region of interest surrounding the vessel of interest on the magnitude image to construct a vessel edge detection mask m(x,y). The velocity images were then multiplied by the mask m(x,y) and volumetric flow rates determined using the identified vessel pixels. Results: In the flow phantom, flow measurements with the magnitude threshold method had significantly less interuser variability compared with the manual method (p < 0.01) and were within 10% (mean 6.0%) of the actual flow versus 35% (mean 18.6%) with the manual method. Regarding flow measurements in the portal vein of six volunteers, the magnitude threshold method was significantly more precise (p < 0.01) than the manual method with a mean standard deviation between the five users of 40.4 ± 12.9 ml/min (range 22-60 ml/min) and 110.4 ± 32.7 ml/min (range 70-155 ml/min), respectively. Conclusion: The magnitude threshold method of vessel edge detection developed in this study yields flow measurements that are accurate in the model system and have significantly less interuser variability than the manual method. This method shows promise for improving the precision of cine phase contrast flow measurements.
KW - Flow, measurements
KW - Magnetic resonance imaging, cine
KW - Magnetic resonance imaging, techniques
UR - http://www.scopus.com/inward/record.url?scp=0028273506&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028273506&partnerID=8YFLogxK
M3 - Article
C2 - 8188918
AN - SCOPUS:0028273506
VL - 18
SP - 469
EP - 475
JO - Journal of Computer Assisted Tomography
JF - Journal of Computer Assisted Tomography
SN - 0363-8715
IS - 3
ER -