{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T01:23:19Z","timestamp":1792113799973,"version":"4.4.0"},"reference-count":32,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"12","content-domain":{"domain":["www.ahajournals.org"],"crossmark-restriction":true},"short-container-title":["Stroke"],"published-print":{"date-parts":[[1999,12]]},"abstract":"<jats:p><jats:italic>Background and Purpose<\/jats:italic>\u2014The circle of Willis (CW) is considered an important collateral pathway in maintaining adequate cerebral blood flow in patients with internal carotid artery (ICA) obstruction. We aimed to investigate the anatomic variation of the CW in patients with severe symptomatic carotid obstructive disease and to analyze diameter changes of its components in relation to varying grades of ICA obstruction and in relation to the presence or absence of (retrograde) collateral flow.<\/jats:p><jats:p><jats:italic>Methods<\/jats:italic>\u2014Seventy-five patients with minor disabling neurological deficits and with ICA stenoses or occlusions were categorized into 4 groups according to the severity of ICA obstruction. This patient population reflected a relatively favorable subgroup of cerebral infarction (considering their minor neurological deficits). All subjects underwent magnetic resonance angiography, including magnetic resonance angiography sensitive to flow direction. CW morphology and the size of its components were determined and compared with those values in control subjects (n=100).<\/jats:p><jats:p><jats:italic>Results<\/jats:italic>\u2014Compared with control subjects, patients demonstrated a significantly higher percentage of entirely complete CW configurations (55% versus 36%,<jats:italic>P<\/jats:italic>=0.02), complete anterior configurations (88% versus 68%,<jats:italic>P<\/jats:italic>=0.002), and complete posterior CW configurations (63% versus 47%,<jats:italic>P<\/jats:italic>=0.04). Patients with severe ICA stenosis did not show significantly increased CW vessel diameters. Patients with ICA occlusion demonstrated a high prevalence of collateral flow through the anterior CW and significantly increased diameters of the communicating channels. Patients with bilateral ICA occlusion relied on collateral flow via the posterior CW and demonstrated a bilateral increase in posterior communicating artery diameters (<jats:italic>P<\/jats:italic>&lt;0.05).<\/jats:p><jats:p><jats:italic>Conclusions<\/jats:italic>\u2014The anatomic and functional configuration of the CW reflects the degree of ICA obstruction.<\/jats:p>","DOI":"10.1161\/01.str.30.12.2671","type":"journal-article","created":{"date-parts":[[2011,6,17]],"date-time":"2011-06-17T20:08:03Z","timestamp":1308341283000},"page":"2671-2678","update-policy":"https:\/\/doi.org\/10.1161\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":162,"title":["Circle of Willis Collateral Flow Investigated by Magnetic Resonance Angiography"],"prefix":"10.1161","volume":"30","author":[{"given":"Monique J.","family":"Hartkamp","sequence":"first","affiliation":[{"name":"From the Department of Radiology (M.J.H., J.v.d.G., K.J.v.E., W.P.T.M.M.) and the Department of Functional Anatomy (B.H.), University Medical Center Utrecht, Utrecht, the Netherlands. Dr Hartkamp is now at the Department of Radiology, University Hospital Nijmegen, Nijmegen, the Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeroen","family":"van der Grond","sequence":"additional","affiliation":[{"name":"From the Department of Radiology (M.J.H., J.v.d.G., K.J.v.E., W.P.T.M.M.) and the Department of Functional Anatomy (B.H.), University Medical Center Utrecht, Utrecht, the Netherlands. Dr Hartkamp is now at the Department of Radiology, University Hospital Nijmegen, Nijmegen, the Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kaspar J.","family":"van Everdingen","sequence":"additional","affiliation":[{"name":"From the Department of Radiology (M.J.H., J.v.d.G., K.J.v.E., W.P.T.M.M.) and the Department of Functional Anatomy (B.H.), University Medical Center Utrecht, Utrecht, the Netherlands. Dr Hartkamp is now at the Department of Radiology, University Hospital Nijmegen, Nijmegen, the Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B.","family":"Hillen","sequence":"additional","affiliation":[{"name":"From the Department of Radiology (M.J.H., J.v.d.G., K.J.v.E., W.P.T.M.M.) and the Department of Functional Anatomy (B.H.), University Medical Center Utrecht, Utrecht, the Netherlands. Dr Hartkamp is now at the Department of Radiology, University Hospital Nijmegen, Nijmegen, the Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Willem P. T. M.","family":"Mali","sequence":"additional","affiliation":[{"name":"From the Department of Radiology (M.J.H., J.v.d.G., K.J.v.E., W.P.T.M.M.) and the Department of Functional Anatomy (B.H.), University Medical Center Utrecht, Utrecht, the Netherlands. Dr Hartkamp is now at the Department of Radiology, University Hospital Nijmegen, Nijmegen, the Netherlands."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","reference":[{"key":"e_1_3_2_1_2","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1177\/096721099400200206","volume":"2","year":"1994","unstructured":"Eastcott HHG. The beginning of stroke prevention by surgery. Cardiovasc Surg. 1994;2:164\u2013169.","journal-title":"Cardiovasc Surg"},{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.28.1.118"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1078-5884(05)80164-9"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199406023302204"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1159\/000146380"},{"key":"e_1_3_2_6_2","first-page":"87","volume":"24","year":"1986","unstructured":"Hillen B. The variability of the circle of Willis: univariate and bivariate analysis. Acta Morphol Neth Scand. 1986;24:87\u2013101.","journal-title":"Acta Morphol Neth Scand"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1148\/radiology.207.1.9530305"},{"key":"e_1_3_2_8_2","first-page":"115","volume":"101","year":"1996","unstructured":"Macchi C, Catini C, Federico C, Gulisano M, Pacini P, Cecchi F, Corcos L, Brizzi E. Magnetic resonance angiographic evaluation of circulus arteriosus cerebri (circle of Willis): a morphologic study in 100 human healthy subjects. Ital J Anat Embryol. 1996;101:115\u2013123.","journal-title":"Ital J Anat Embryol"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0009-9260(97)80003-7"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1161\/circ.92.10.3122"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/0021-9290(88)90013-9"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1080\/01616412.1996.11740417"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.26.2.214"},{"key":"e_1_3_2_14_2","first-page":"777","volume":"17","year":"1996","unstructured":"Baumgartner RW, Baumgartner I, Mattle HP, Schroth G. Transcranial color-coded duplex sonography in unilateral flow-restrictive extracranial carotid artery disease. AJNR Am J Neuroradiol. 1996;17:777\u2013783.","journal-title":"Am J Neuroradiol"},{"key":"e_1_3_2_15_2","first-page":"127","volume":"18","year":"1997","unstructured":"Baumgartner RW, Baumgartner I, Mattle HP, Schroth G. Transcranial color-coded duplex sonography in the evaluation of collateral flow through the circle of Willis. AJNR Am J Neuroradiol. 1997;18:127\u2013133.","journal-title":"Am J Neuroradiol"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1053-0770(96)80173-X"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.27.3.486"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1080\/01616412.1996.11740465"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.27.9.1672"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1111\/jon199663137"},{"key":"e_1_3_2_21_2","first-page":"19","volume":"14","year":"1993","unstructured":"Ross MR, Pelc NJ, Enzmann DR. Qualitative phase contrast MRA in the normal and abnormal circle of Willis. AJNR Am J Neuroradiol. 1993;14:19\u201325.","journal-title":"Am J Neuroradiol"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1002\/jmri.1880030409"},{"key":"e_1_3_2_23_2","first-page":"1495","volume":"17","year":"1996","unstructured":"Stock KW, Wetzel S, Kirsch E, Bongartz G, Steinbrich W, Radue EW. Anatomic evaluation of the circle of Willis: MR angiography versus intraarterial digital subtraction angiography. AJNR Am J Neuroradiol. 1996;17:1495\u20131499.","journal-title":"Am J Neuroradiol"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00588129"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199108153250701"},{"key":"e_1_3_2_26_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.28.8.1595"},{"key":"e_1_3_2_27_2","doi-asserted-by":"publisher","DOI":"10.1002\/ana.410440206"},{"key":"e_1_3_2_28_2","doi-asserted-by":"publisher","DOI":"10.1001\/archneur.1963.00460040068006"},{"key":"e_1_3_2_29_2","doi-asserted-by":"publisher","DOI":"10.1001\/archneur.1963.00460010024002"},{"key":"e_1_3_2_30_2","first-page":"127","volume":"18","year":"1997","unstructured":"Baumgartner RW, Baumgartner I, Mattle HP, Schroth G. Transcranial color-coded duplex sonography in the evaluation of collateral flow through the circle of Willis. AJNR Am J Neuroradiol. 1997;18:127\u2013133.","journal-title":"Am J Neuroradiol"},{"key":"e_1_3_2_31_2","doi-asserted-by":"publisher","DOI":"10.1161\/str.27.2.296"},{"key":"e_1_3_2_32_2","doi-asserted-by":"crossref","unstructured":"Martin PJ Smith JL Gaunt ME Naylor AR. Assessment of intracranial primary collaterals using transcranial color- coded real-time sonography. J Neuroimaging. 199;5:199\u2013205.","DOI":"10.1111\/jon199554199"}],"container-title":["Stroke"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ahajournals.org\/doi\/full\/10.1161\/01.STR.30.12.2671","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,6]],"date-time":"2025-03-06T08:38:06Z","timestamp":1741250286000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ahajournals.org\/doi\/10.1161\/01.STR.30.12.2671"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,12]]},"references-count":32,"journal-issue":{"issue":"12","published-print":{"date-parts":[[1999,12]]}},"alternative-id":["10.1161\/01.STR.30.12.2671"],"URL":"https:\/\/doi.org\/10.1161\/01.str.30.12.2671","relation":{},"ISSN":["0039-2499","1524-4628"],"issn-type":[{"value":"0039-2499","type":"print"},{"value":"1524-4628","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,12]]},"assertion":[{"value":"1999-03-30","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"1999-09-09","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"1999-12-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}