title: Cerebrovascular insufficiency as the criterion for revascularization procedures in selected patients: a correlation study of xenon contrast-enhanced CT and PWI.
abstract: In order to identify patients who suffer from hemodynamic cerebral insufficiency and can benefit from cerebral revascularization procedures, xenon-CT scanning has been established to reliably measure the critical cerebrovascular reserve capacity. As a need for alternative quantification methods arises, this study aims to characterize the significance of both time-to-peak (TTP) and mean transit time (MTT) in perfusion-weighted imaging (PWI) in this particular subset of patients. Ten patients in routine preoperative work-up for cerebral revascularization were prospectively enrolled and underwent both XeCT scanning and PWI. Cerebrovascular reserve capacity (CVRC) was calculated for each region of interest (ROI, n = 504) after administration of a vasoactive stimulus. ROIs were anatomically matched with those of PWI after TTP and MTT were calculated. Highly significant negative correlation was found for TTP and CVRC for all ROIs (r = -0.3954, p < 0.0001; symptomatic ROIs: r = -0.4867, p < 0.0001). Correlation was weak for MTT and CVCR (r = -0.1287; p < 0.01). The optimum threshold for TTP to detect impaired cerebrovascular reactivity in our patient group was 4 s (specificity 90.8%, sensitivity 44.4%) for all ROIs (TTP > 4.4 s for symptomatic ROIs, specificity 88.4%, sensitivity 62.7%). An approximative equation to calculate the probability of pathological findings could be derived from the data. The positive predictive value (PPV) was 0.76 (symptomatic 0.78) with a negative predictive value (NPV) of 0.71 (symptomatic 0.78). While PWI currently is not able to replace XeCT in the direct quantification of CVRC, it may serve as a readily available follow-up tool. A TTP threshold of greater than 4 s allows to confirm a cerebrovascular compromise in a selected high-risk subgroup of patients.
authors.affiliation: Department of Neurosurgery, University Hospital Mannheim, University of Heidelberg, Germany. gerrit.schubert@nch.ma.uni-heidelberg.de
authors.forename: Gerrit Alexander
authors.initials: GA
authors.lastname: Schubert
authors.forename: Carolin
authors.initials: C
authors.lastname: Weinmann
authors.forename: Marcel
authors.initials: M
authors.lastname: Seiz
authors.forename: Lars
authors.initials: L
authors.lastname: Gerigk
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.forename: Peter
authors.initials: P
authors.lastname: Horn
authors.forename: Claudius
authors.initials: C
authors.lastname: Thomé
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D002548:Cerebral Revascularization; D002560:Cerebrovascular Circulation / Q000502:physiology; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D003251:Constriction, Pathologic; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology; D009072:Moyamoya Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D012372:ROC Curve; D014057:Tomography, X-Ray Computed
references.citation: J Neurosurg. 1989 Sep;71(3):464-6
references.pmid: 2769400
references.citation: AJNR Am J Neuroradiol. 2006 Feb;27(2):391-7
references.pmid: 16484417
references.citation: Stroke. 2005 Jun;36(6):1153-9
references.pmid: 15914768
references.citation: AJNR Am J Neuroradiol. 2001 Sep;22(8):1543-9
references.pmid: 11559502
references.citation: N Engl J Med. 1985 Nov 7;313(19):1191-200
references.pmid: 2865674
references.citation: AJNR Am J Neuroradiol. 2001 Jun-Jul;22(6):1056-61
references.pmid: 11415897
references.citation: J Comput Assist Tomogr. 1981 Jun;5(3):334-40
references.pmid: 7240506
references.citation: J Cereb Blood Flow Metab. 1991 Sep;11(5):716-25
references.pmid: 1908474
references.citation: Magn Reson Imaging. 2000 Jan;18(1):1-11
references.pmid: 10642097
references.citation: J Comput Assist Tomogr. 2002 Mar-Apr;26(2):272-8
references.pmid: 11884786
references.citation: Neurosurgery. 2000 Jan;46(1):37-42; discussion 42-3
references.pmid: 10626933
references.citation: Neurosurg Focus. 2003 Mar 15;14(3):e9
references.pmid: 15709726
references.citation: J Vasc Surg. 1995 Feb;21(2):338-44; discussion 344-5
references.pmid: 7853605
references.citation: AJNR Am J Neuroradiol. 2000 Sep;21(8):1450-6
references.pmid: 11003277
references.citation: J Cereb Blood Flow Metab. 2003 Jan;23(1):121-35
references.pmid: 12500097
references.citation: J Neurosurg. 1994 Aug;81(2):236-44
references.pmid: 8027807
references.citation: Science. 1982 Mar 5;215(4537):1267-8
references.pmid: 7058347
references.citation: J Comput Assist Tomogr. 1999 Mar-Apr;23(2):257-64
references.pmid: 10096334
references.citation: Stroke. 1978 Mar-Apr;9(2):123-30
references.pmid: 417427
references.citation: J Neurosurg. 1993 Oct;79(4):483-9
references.pmid: 8410214
references.citation: Skull Base. 2005 Aug;15(3):191-205
references.pmid: 16175229
references.citation: AJNR Am J Neuroradiol. 1991 Jan-Feb;12(1):86-7
references.pmid: 1899527
references.citation: Stroke. 2005 Sep;36(9):e83-99
references.pmid: 16100027
references.citation: Rofo. 1999 Jul;171(1):3-14
references.pmid: 10464498
references.citation: J Comput Assist Tomogr. 2005 Mar-Apr;29(2):270-7
references.pmid: 15772551
references.citation: AJNR Am J Neuroradiol. 2006 May;27(5):1059-69
references.pmid: 16687543
references.citation: Neurosurg Clin N Am. 1996 Oct;7(4):605-16
references.pmid: 8905775
references.citation: AJNR Am J Neuroradiol. 2001 Feb;22(2):248-54
references.pmid: 11156764
references.citation: Stroke. 2001 Aug;32(8):1811-7
references.pmid: 11486110
references.citation: Neuroradiology. 1991;33(3):217-22
references.pmid: 1881538
references.citation: AJNR Am J Neuroradiol. 2001 May;22(5):905-14
references.pmid: 11337336
references.citation: J Magn Reson Imaging. 2005 Dec;22(6):710-7
references.pmid: 16261573
references.citation: Radiology. 1987 Apr;163(1):251-4
references.pmid: 3823444
references.citation: Neurosurgery. 1993 Jun;32(6):912-8; discussion 918-9
references.pmid: 8327091
references.citation: Radiology. 1994 Dec;193(3):637-41
references.pmid: 7972800
references.citation: Stroke. 2004 Dec;35(12):2843-7
references.pmid: 15514190
references.citation: AJR Am J Roentgenol. 2002 Jul;179(1):229-35
references.pmid: 12076942
references.citation: J Vasc Surg. 1986 Feb;3(2):298-304
references.pmid: 3484790
references.citation: AJNR Am J Neuroradiol. 1991 Mar-Apr;12(2):201-13
references.pmid: 1902015
references.citation: Neurology. 1999 Jun 10;52(9):1750-6
references.pmid: 10371519
references.citation: Skull Base. 2005 Feb;15(1):7-14
references.pmid: 16148980
references.citation: J Neurosurg. 1985 Mar;62(3):324-33
references.pmid: 3871843