Measurement of internal carotid artery stenosis from source MR angiograms.
OBJECTIVE
To determine whether interpretation of internal carotid artery (ICA) stenosis from source partitions is more accurate than interpretation from maximum-intensity projections (MIPs) from three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography.


METHODS
The percentage of diameter ICA stenosis was measured on source images and MIPs from sagittal (n = 150) and transverse (n = 140) 3D TOF MR angiography. Measurements were compared with those from conventional angiography.


RESULTS
Sensitivity and specificity for distinguishing 70%-99% stenosis were 96% and 78%, respectively, for sagittal MIPs, 88% and 90% for sagittal source images, 92% and 86% for transverse MIPs, and 92% and 95% for transverse source images. Areas under the receiver operating characteristic curves statistically significantly increased (P < .05) with interpretation from source images. Complete loss of intravascular signal was not encountered on source partitions except within a greater than 85% stenosis.


CONCLUSIONS
Interpretation of source partitions rather than MIPs reduces the tendency for overestimation of stenosis with MR angiography and improves the specificity for discriminating 70%-99% stenosis.
Anderson
C M
CM
Section of Radiology (114D), Veteran Affairs Medical Center, San Francisco, CA 94121.
Lee
R E
RE
Levin
D L
DL
de la Torre Alonso
S
S
Saloner
D
D
D000368:Aged; D015901:Angiography, Digital Subtraction; D002343:Carotid Artery, Internal / Q000473:pathology; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000453:epidemiology; D017023:Coronary Angiography; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity