Delineation and segmentation of cerebral tumors by mapping blood-brain barrier disruption with dynamic contrast-enhanced CT and tracer kinetics modeling-a feasibility study.
Dynamic contrast-enhanced (DCE) imaging is a promising approach for in vivo assessment of tissue microcirculation. Twenty patients with clinical and routine computed tomography (CT) evidence of intracerebral neoplasm were examined with DCE-CT imaging. Using a distributed-parameter model for tracer kinetics modeling of DCE-CT data, voxel-level maps of cerebral blood flow (F), intravascular blood volume (vi) and intravascular mean transit time (t1) were generated. Permeability-surface area product (PS), extravascular extracellular blood volume (ve) and extraction ratio (E) maps were also calculated to reveal pathologic locations of tracer extravasation, which are indicative of disruptions in the blood-brain barrier (BBB). All maps were visually assessed for quality of tumor delineation and measurement of tumor extent by two radiologists. Kappa (kappa) coefficients and their 95% confidence intervals (CI) were calculated to determine the interobserver agreement for each DCE-CT map. There was a substantial agreement for the tumor delineation quality in the F, ve and t1 maps. The agreement for the quality of the tumor delineation was excellent for the vi, PS and E maps. Concerning the measurement of tumor extent, excellent and nearly excellent agreement was achieved only for E and PS maps, respectively. According to these results, we performed a segmentation of the cerebral tumors on the base of the E maps. The interobserver agreement for the tumor extent quantification based on manual segmentation of tumor in the E maps vs. the computer-assisted segmentation was excellent (kappa = 0.96, CI: 0.93-0.99). The interobserver agreement for the tumor extent quantification based on computer segmentation in the mean images and the E maps was substantial (kappa = 0.52, CI: 0.42-0.59). This study illustrates the diagnostic usefulness of parametric maps associated with BBB disruption on a physiology-based approach and highlights the feasibility for automatic segmentation of cerebral tumors.
Bisdas
S
S
Department of Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University Hospital, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany. s.bisdas@med.uni-frankfurt.de
Yang
X
X
Lim
C C T
CC
Vogl
T J
TJ
Koh
T S
TS
D001810:Blood Volume; D001812:Blood-Brain Barrier; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D007472:Iohexol
Phys Med Biol. 2003 Sep 21;48(18):3085-100
14529212
AJNR Am J Neuroradiol. 2002 May;23 (5):828-32
12006286
Acta Physiol Scand. 1965 Aug;64(4):407-17
5853034
Acad Radiol. 2001 May;8(5):384-91
11345268
IEEE Trans Biomed Eng. 2003 Feb;50(2):159-67
12665029
Radiology. 2004 Sep;232(3):631-2
15333789
Magn Reson Med. 2000 Sep;44(3):466-73
10975900
Acad Radiol. 2002 Aug;9 Suppl 2:S364-7
12188277
J Magn Reson Imaging. 1999 Sep;10(3):267-76
10508286
Br J Cancer. 2005 May 9;92(9):1599-610
15870830
J Magn Reson Imaging. 1999 Sep;10(3):223-32
10508281
J Magn Reson Imaging. 2005 Jun;21(6):683-93
15906330
Am J Physiol. 1959 Dec;197:1205-10
14437359
Acta Radiol. 2006 Oct;47(8):852-61
17050367
Am J Physiol. 1966 Jun;210(6):1299-303
5923068
Eur Radiol. 2007 Sep;17 (9):2352-8
17318605
Eur Radiol. 2001;11(7):1231-41
11471617
Radiology. 2003 Aug;228(2):303-8
12819342
Eur Radiol. 2007 Jan;17 (1):39-47
16703311
J Cereb Blood Flow Metab. 1998 Dec;18(12):1365-77
9850149
Radiology. 2004 Sep;232(3):921-30
15247436
Oncologist. 2004;9(5):528-37
15477637
Eur J Cancer. 2002 Nov;38(16):2079-84
12387833
Eur Radiol. 2007 Apr;17(4):919-26
17008987
J Cereb Blood Flow Metab. 1987 Aug;7(4):443-63
3611204
Radiology. 1999 Oct;213(1):141-9
10540654