Accuracy of microvascular measurements obtained from micro-CT images.
Early changes in branching geometry of microvasculature and its associated impact on the perfusion distribution in diseases, especially those in which different branching generations are affected differently, require the ability to analyze intact vascular trees over a wide range of scales. Micro-CT offers an excellent framework to analyze the microvascular branching geometry. Such an analysis requires methods to be developed that can accurately characterize branching properties, such as branch diameter, length, branching angle, and branch interconnectivity of the microvasculature. The purpose of this article is to report the results of a study of two human intramyocardial coronary vascular tree casts in which the accuracy of micro-CT vascular imaging and its analysis are tested against measurements made through an optical microscope (used as the "gold-standard"). Methods related to image segmentation of the vascular lumen, vessel tree centerline extraction, individual branch segment measurement, and compensating for the non-ideal modulation transfer function of micro-CT scanners are presented. The extracted centerline accurately characterized the hierarchical structure of the vascular tree casts in terms of "parent-branch" relationships which allowed each interbranch segments' dimensions to be compared to the optical measurement method. The comparison results show a close to ideal 1:1 relationship for both length and diameter measurements made by the two methods. Combining the results from both specimens, the standard deviation of the difference between measurement methods was 19 microm for the measurement of interbranch segment diameters (ranging from 12 to 769 microm), and 172 microm for the measurement of interbranch segment lengths (ranging from 14 to 3252 microm). These results suggest that our micro-CT image analysis method can be used to characterize a vascular tree's hierarchical structure, and accurately measure interbranch segment lengths and diameters.
Kline
Timothy L
TL
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Zamir
Mair
M
Ritman
Erik L
EL
D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D055806:Microvessels / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*
Med Phys. 1980 May-Jun;7(3):238-48
7393149
Am J Physiol Heart Circ Physiol. 2008 Feb;294(2):H714-23
18055515
Med Phys. 2002 Jul;29(7):1622-33
12148745
Proc Biol Sci. 1998 Mar 7;265(1394):439-44
9523440
Tohoku J Exp Med. 1963 Mar 25;79:168-98
13979440
IEEE Trans Med Imaging. 2009 Apr;28(4):487-93
19272984
Ann Biomed Eng. 2006 Sep;34(9):1420-8
16838126
IEEE Trans Pattern Anal Mach Intell. 1980 Jan;2(1):75-7
22499627
Med Image Anal. 2007 Dec;11(6):630-47
17827050
Ann N Y Acad Sci. 1990;591:392-401
2197931
Am J Physiol. 1998 Sep;275(3):H1103-14
9724319
Am J Physiol. 1996 Feb;270(2 Pt 2):H545-53
8779829
Am J Physiol Heart Circ Physiol. 2004 Dec;287(6):H2493-500
15548725
Comput Med Imaging Graph. 1989 Nov-Dec;13(6):433-54
2688869
Comput Biol Med. 2007 Dec;37(12):1802-20
17669390
Am J Anat. 1982 Apr;163(4):295-307
7091015
Med Phys. 2007 Feb;34(2):627-38
17388180
Am J Physiol Heart Circ Physiol. 2006 Nov;291(5):H2136-41
16766647
J Magn Reson Imaging. 1998 Nov-Dec;8(6):1228-35
9848733
Ann Biomed Eng. 2008 Mar;36(3):356-68
18228141
Am J Physiol Heart Circ Physiol. 2006 Jul;291(1):H296-309
16399870
Blood Vessels. 1987;24(1-2):76-84
3567367
Can J Cardiol. 1996 Jun;12(6):593-9
8665422