Double anastomoses between posterior cerebral artery and posterior communicating artery diagnosed by magnetic resonance angiography

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Methods An 83-year-old woman with left pulsatile tinnitus underwent cranial magnetic resonance angiography (MRA) using a 3-Tesla scanner. MRA was performed using a standard 3-dimensional time-of-flight technique. Results MRA showed no dural arteriovenous fistula; however, there was a stenotic lesion in the precavernous segment of the left internal carotid artery (ICA). This lesion was considered to be the cause of her symptoms. In addition, the left PCA arose from the basilar artery and the left ICA. There was a small connecting artery between these two PCAs at their proximal segments. These two PCAs fused distally and formed a single PCA. Partial maximum intensity projection (MIP) images showed that the left anterior choroidal artery (AChA) appeared normal. Thus, we concluded that there was no hyperplastic AChA, and there were double anastomoses between the left PCA and PCoA. Conclusion We diagnosed the first case of double anastomosis between the PCA and the PCoA. Careful observation using MRA is important for the detection of rare arterial variations. Partial MIP MRA images are useful for identifying tiny arteries, such as the AChA. Anastomosis Anterior choroidal artery Cerebral arterial variations Magnetic resonance angiography Posterior cerebral artery Posterior communicating artery Figures Figure 1 Figure 2 Figure 3 Introduction The posterior cerebral artery (PCA) is normally supplied by the basilar artery (BA) and the internal carotid artery (ICA) via the posterior communicating artery (PCoA). The P1 segment of the PCA is located from the origin to the junction between the PCA and PCoA. The adult-type PCA was supplied only by the BA, and the fetal-type PCA was supplied only by ICA. When both PCAs are present without fusion, they are called duplicated PCA [4,8]. When both PCAs fuse more distally than the usual point, there is an extremely long P1 segment and PCoA [3,7,9]. We report a case of PCA and PCoA distal fusion with a proximal communicating artery between the two arteries that was diagnosed using magnetic resonance angiography (MRA). This can be regarded as double anastomoses between the PCA and PCoA. We could not find any such reports in relevant English-language literature. Case report An 83-year-old woman with left pulsatile tinnitus underwent cranial MRA using a 3-Tesla scanner (MAGNETOM Skyra; Siemens Healthineers, Erlangen, Germany) for the evaluation of cerebral vascular lesions. MRA was performed using a standard 3-dimensional time-of-flight technique. The imaging parameters were as follows: flip angle, 16°; repetition time, 30.0 s; echo time, 3.7 s; slice thickness, 0.6 mm; number of slices, 160; slab thickness, 96 mm; field of view, 28.0 × 20.0 cm; and imaging matrix, 320 × 272. MRA showed no dural arteriovenous fistula; however, there was a stenotic lesion in the precavernous segment of the left ICA. This lesion was considered the cause of the symptoms. In addition, the left PCA arose from the BA and left ICA. There was a small connecting artery between these two PCAs at their proximal segments, The two PCAs fused distally and formed a single PCA. Partial maximum intensity projection (MIP) images showed that a tiny left anterior choroidal artery (AChA) arose from the normal point of the ICA (Figs. 1 , 2 ). Thus, we concluded that there was no hyperplastic AChA, and double anastomoses were present between the left PCA and PCoA (Fig. 3 ). No surgical treatment was administered for the stenotic lesion of the left ICA. The patient’s clinical course was uneventful for 2 years. Discussion With the exception of the aplastic P1 segment of the PCA variation (so-called fetal-type PCA), variations in PCA are rare. Fenestration, early bifurcation, complete duplication, accessory PCA, and replaced PCA are known PCA variations [8]. Normally, the P1 segment of the PCA and PCoA fuse proximally to form the main PCA. As mentioned in the Introduction , if the point of fusion is located extremely distally, the P1 and PCoA will be extremely long [3,7,9]. The present patient had a similar distal fusion; however, there was also a proximal connecting artery between the two arteries. This connecting artery can be regarded as part of the PCoA. Therefore, there are double anastomoses between the PCA and PCoA. We could not find any such reports in the relevant English-language literature. If the PCoA does not fuse with the PCA arising from the BA and supplies part of the PCA branches, there are two PCAs. This extremely rare variation is called duplicated PCAs [4,8]. The AChA is rarely hyperplastic because a branch of the PCA arises from the AChA. In 2016, the first author (A.U.) reported that the MR angiographic prevalence of hyperplastic AChAs was 0.55% [8]. The hyperplastic AChA supplies one or all branches of the PCA. The term “accessory PCA” was proposed to describe the variation in which the AChA supplies one of the branches of the PCA, while “replaced PCA” was proposed to describe an AChA that supplies all branches of the PCA [8]. In the case of an accessory PCA, there are two PCAs. This is not true for duplicated PCAs but is frequently confused with duplication and is regarded as a true fetal-type PCA [2,5,6]. In our patient, the normal tiny left AChA arose distal to the origin of the large and long PCoA (Fig. 2 ). Therefore, our patient did not have a hyperplastic AChA. Anastomosis between the PCA and accessory PCA is a rare variation [10]. There are four potential anastomoses between the PCA and accessory PCA. Using catheter angiography, Chen and Barkovich [1] reported a case of double anastomosis between the PCA and an accessory PCA. In cases of segmental hypoplasia/occlusion/stenosis of the PCA, collateral blood flow develops from the accessory PCA. The clinical significance of PCA variations in our patient is potential collateral blood supply via two anastomoses in cases of occlusion of the proximal PCA or long PCoA. Careful observation using MRA is required for the correct diagnosis of rare arterial variations. Partial MIP MRA images are useful for identifying tiny arteries, such as the AChA. Conclusions We diagnosed the first case of double anastomosis between the PCA and PCoA. Careful observation using MRA is important for the detection of rare arterial variations. Partial MIP MRA images are useful for identifying small arteries. Declarations Conflict of interest The authors declare no competing interests. Ethical approval and consent to participate All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. Consent for publication The patient signed informed consent regarding publishing his data and figures. Funding The authors did not receive support from any organization for the submitted work. Author Contribution AU carried out the study design and drafted the manuscript. AU and RK reviewed the manuscript critically, and have read and approved the final manuscript. Data availability Not applicable. References Chen CJ, Barkovich AJ (1998) A hyperplastic anterior choroidal artery with double persistent anastomotic channels. AJNR Am J Neuroradiol 19:1758–1760 Coulier B (2018) Duplication of the posterior cerebral artery (PCA) or "true fetal PCA": an extremely rare variant. J Belg Soc Radiol 102:29. doi: 10.5334/jbsr.1502 Endo H, Ono H, Asayama B, Nakamura H (2023) Extremely long posterior cerebral artery P1 segment. Surg Radiol Anat 45:773–775. doi: 10.1007/s00276-023-03137-4 Endo H, Ono H, Nakamura H (2023) Complete duplication of the posterior cerebral artery. Surg Radiol Anat 45:359–361. doi: 10.1007/s00276-023-03095-x Kaplanoglu H, Turan A, Kaplanoglu V, Karacif O (2020) Fetal posterior cerebral artery duplication, true fetal posterior cerebral artery variation and trifurcation anterior cerebral artery association. Surg Radiol Anat 42:1267–1270. doi: 10.1007/s00276-020-02523-6 Masoud H, Nguyen TN, Thatcher J, Barest G, Norbash AM. (2015) Duplication of the posterior cerebral artery and the 'true fetal' variant. Interv Neurol 4:64–67. doi: 10.1159/000437310 Matsuda M, Uchino A, Saito N, Neki H, Kohyama S, Yamane F (2017) Duplicate origin and extremely long P1 segment of the posterior cerebral artery diagnosed by MR angiography. Surg Radiol Anat 39:699–702. doi: 10.1007/s00276-016-1769-8 Uchino A, Saito N, Takahashi M, Okano N, Tanisaka M (2016) Variations of the posterior cerebral artery diagnosed by MR angiography at 3 tesla. Neuroradiology 58:141–146. doi: 10.1007/s00234-015-1614-5 Uchino A, Suzuki C, Tanaka M (2015) Extremely long posterior communicating artery diagnosed by MR angiography: report of two cases. Surg Radiol Anat 37:565–568. doi: 10.1007/s00276-014-1413-4 Uchino A, Tokushige K (2024) Posterior cerebral artery (PCA)-accessory PCA (hyperplastic anterior choroidal artery) anastomosis detected on magnetic resonance angiography. Surg Radiol Anat 46:679–683. doi: 10.1007/s00276-024-03350-9 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 11 Mar, 2025 Read the published version in Surgical and Radiologic Anatomy → Version 1 posted Editorial decision: Revision requested 12 Feb, 2025 Reviews received at journal 12 Feb, 2025 Reviews received at journal 11 Feb, 2025 Reviews received at journal 10 Feb, 2025 Reviewers agreed at journal 05 Feb, 2025 Reviewers agreed at journal 03 Feb, 2025 Reviews received at journal 01 Feb, 2025 Reviewers agreed at journal 01 Feb, 2025 Reviewers agreed at journal 01 Feb, 2025 Reviews received at journal 31 Jan, 2025 Reviewers agreed at journal 26 Jan, 2025 Reviewers invited by journal 23 Jan, 2025 Editor assigned by journal 23 Jan, 2025 Submission checks completed at journal 23 Jan, 2025 First submitted to journal 22 Jan, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5883848","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":407362239,"identity":"c0916d24-cb14-44d9-8411-c3331f7c6eef","order_by":0,"name":"Akira Uchino","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIiWNgGAWjYHACNoYEBgYe+/bmgw+APB4+YrXIGfAcSzYAaWEjSgsQGBtI5JhJwLn4AP+M5GcPHu6wSdzOkJZW+TXHToaNgfnhoxt4tEjcSDM3SDyTlriz4fCx27LbkoEOYzM2zsFnzY0cNonEtsOJDQfb0m5LbmMGauFhk8anRR6u5TCPWbHktnrCWgygWowNjvGYMX7cdpiwFsMzz8yAWtLkJHvYkqUZtx3nYWMm4Be548nPJH+22fDwyz8++PHntmp7fvbmh4/xeh8ZMPOASWKVgwDjD1JUj4JRMApGwYgBAKOfRxxHpWQSAAAAAElFTkSuQmCC","orcid":"","institution":"Saitama Sekishinkai Hospital","correspondingAuthor":true,"prefix":"","firstName":"Akira","middleName":"","lastName":"Uchino","suffix":""},{"id":407362241,"identity":"e350f194-c814-41d9-bc6d-246daa23d309","order_by":1,"name":"Ryushi Kondo","email":"","orcid":"","institution":"Saitama Sekishinkai Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ryushi","middleName":"","lastName":"Kondo","suffix":""}],"badges":[],"createdAt":"2025-01-22 22:38:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5883848/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5883848/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00276-025-03603-1","type":"published","date":"2025-03-11T15:57:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":75310588,"identity":"74cd2c55-52aa-4392-8699-552498b0fa75","added_by":"auto","created_at":"2025-02-03 09:03:57","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1221997,"visible":true,"origin":"","legend":"\u003cp\u003eInfero-superior projection of volume-rendering (VR) image of magnetic resonance angiography (MRA). A stenotic lesion is present at the precavernous segment of the left internal carotid artery (ICA) (\u003cem\u003ethin long arrow\u003c/em\u003e). The left posterior cerebral artery (PCA) is arising from both basilar artery and left ICA. A small connecting artery is located between these two PCAs at their proximal segments (\u003cem\u003elong arrow\u003c/em\u003e). These two PCAs fuse distally and form single PCA (\u003cem\u003eshort arrow\u003c/em\u003e).\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5883848/v1/25bb9b060c14842f49a3b5c0.png"},{"id":75310586,"identity":"a33cbbd4-0404-491e-aac9-f97657796fa9","added_by":"auto","created_at":"2025-02-03 09:03:57","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":374444,"visible":true,"origin":"","legend":"\u003cp\u003eRight lateral with special oblique projection of a partial maximum-intensity-projection (MIP) image of the left PCA territory. The \u003cem\u003ethin short arrow\u003c/em\u003e indicates the anterior choroidal artery. The \u003cem\u003elong arrow\u003c/em\u003eindicates the connecting artery between two PCAs. The \u003cem\u003eshort arrow \u003c/em\u003eis the point of fusion of the PCAs. Thus, this variation can be regarded as double anastomoses between the PCA and the posterior communicating artery (PCoA).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-5883848/v1/9b057b3587fcc1585af5b2fc.png"},{"id":75312092,"identity":"4f8f5677-882f-45a0-ae2b-ff685e3e1aac","added_by":"auto","created_at":"2025-02-03 09:11:57","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":103571,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic illustration of the arterial system of this patient (infero-superior projection)\u003c/p\u003e\n\u003cp\u003eThe \u003cem\u003elong arrow\u003c/em\u003e indicates the connecting artery between the two PCAs. The \u003cem\u003eshort arrow\u003c/em\u003e indicates the point of fusion of the PCAs.\u003c/p\u003e\n\u003cp\u003eACA, anterior cerebral artery; AChA, anterior choroidal artery; BA, basilar artery; ICA, internal carotid artery; MCA, middle cerebral artery; PCA, posterior cerebral artery; PCoA, posterior communicating artery; SCA, superior cerebellar artery.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-5883848/v1/01c6dece7144846907ae9cbe.png"},{"id":78689145,"identity":"82df9631-de60-44ad-8b1e-8a644d368d9f","added_by":"auto","created_at":"2025-03-17 16:11:52","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1870285,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5883848/v1/f1273396-871f-479a-b28d-dbcbe25a1e63.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Double anastomoses between posterior cerebral artery and posterior communicating artery diagnosed by magnetic resonance angiography","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe posterior cerebral artery (PCA) is normally supplied by the basilar artery (BA) and the internal carotid artery (ICA) via the posterior communicating artery (PCoA). The P1 segment of the PCA is located from the origin to the junction between the PCA and PCoA. The adult-type PCA was supplied only by the BA, and the fetal-type PCA was supplied only by ICA. When both PCAs are present without fusion, they are called duplicated PCA [4,8]. When both PCAs fuse more distally than the usual point, there is an extremely long P1 segment and PCoA [3,7,9].\u003c/p\u003e \u003cp\u003eWe report a case of PCA and PCoA distal fusion with a proximal communicating artery between the two arteries that was diagnosed using magnetic resonance angiography (MRA). This can be regarded as double anastomoses between the PCA and PCoA. We could not find any such reports in relevant English-language literature.\u003c/p\u003e"},{"header":"Case report","content":"\u003cp\u003eAn 83-year-old woman with left pulsatile tinnitus underwent cranial MRA using a 3-Tesla scanner (MAGNETOM Skyra; Siemens Healthineers, Erlangen, Germany) for the evaluation of cerebral vascular lesions. MRA was performed using a standard 3-dimensional time-of-flight technique. The imaging parameters were as follows: flip angle, 16\u0026deg;; repetition time, 30.0 s; echo time, 3.7 s; slice thickness, 0.6 mm; number of slices, 160; slab thickness, 96 mm; field of view, 28.0 \u0026times; 20.0 cm; and imaging matrix, 320 \u0026times; 272.\u003c/p\u003e \u003cp\u003eMRA showed no dural arteriovenous fistula; however, there was a stenotic lesion in the precavernous segment of the left ICA. This lesion was considered the cause of the symptoms. In addition, the left PCA arose from the BA and left ICA. There was a small connecting artery between these two PCAs at their proximal segments, The two PCAs fused distally and formed a single PCA. Partial maximum intensity projection (MIP) images showed that a tiny left anterior choroidal artery (AChA) arose from the normal point of the ICA (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e,\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Thus, we concluded that there was no hyperplastic AChA, and double anastomoses were present between the left PCA and PCoA (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eNo surgical treatment was administered for the stenotic lesion of the left ICA. The patient\u0026rsquo;s clinical course was uneventful for 2 years.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eWith the exception of the aplastic P1 segment of the PCA variation (so-called fetal-type PCA), variations in PCA are rare. Fenestration, early bifurcation, complete duplication, accessory PCA, and replaced PCA are known PCA variations [8]. Normally, the P1 segment of the PCA and PCoA fuse proximally to form the main PCA. As mentioned in the \u003cb\u003eIntroduction\u003c/b\u003e, if the point of fusion is located extremely distally, the P1 and PCoA will be extremely long [3,7,9]. The present patient had a similar distal fusion; however, there was also a proximal connecting artery between the two arteries. This connecting artery can be regarded as part of the PCoA. Therefore, there are double anastomoses between the PCA and PCoA. We could not find any such reports in the relevant English-language literature.\u003c/p\u003e \u003cp\u003eIf the PCoA does not fuse with the PCA arising from the BA and supplies part of the PCA branches, there are two PCAs. This extremely rare variation is called duplicated PCAs [4,8]. The AChA is rarely hyperplastic because a branch of the PCA arises from the AChA. In 2016, the first author (A.U.) reported that the MR angiographic prevalence of hyperplastic AChAs was 0.55% [8]. The hyperplastic AChA supplies one or all branches of the PCA. The term \u0026ldquo;accessory PCA\u0026rdquo; was proposed to describe the variation in which the AChA supplies one of the branches of the PCA, while \u0026ldquo;replaced PCA\u0026rdquo; was proposed to describe an AChA that supplies all branches of the PCA [8]. In the case of an accessory PCA, there are two PCAs. This is not true for duplicated PCAs but is frequently confused with duplication and is regarded as a true fetal-type PCA [2,5,6]. In our patient, the normal tiny left AChA arose distal to the origin of the large and long PCoA (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Therefore, our patient did not have a hyperplastic AChA.\u003c/p\u003e \u003cp\u003eAnastomosis between the PCA and accessory PCA is a rare variation [10]. There are four potential anastomoses between the PCA and accessory PCA. Using catheter angiography, Chen and Barkovich [1] reported a case of double anastomosis between the PCA and an accessory PCA. In cases of segmental hypoplasia/occlusion/stenosis of the PCA, collateral blood flow develops from the accessory PCA.\u003c/p\u003e \u003cp\u003eThe clinical significance of PCA variations in our patient is potential collateral blood supply via two anastomoses in cases of occlusion of the proximal PCA or long PCoA. Careful observation using MRA is required for the correct diagnosis of rare arterial variations. Partial MIP MRA images are useful for identifying tiny arteries, such as the AChA.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eWe diagnosed the first case of double anastomosis between the PCA and PCoA. Careful observation using MRA is important for the detection of rare arterial variations. Partial MIP MRA images are useful for identifying small arteries.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003cstrong\u003eConflict of interest\u003c/strong\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eEthical approval and consent to participate\u003c/strong\u003e \u003cp\u003eAll procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003e The patient signed informed consent regarding publishing his data and figures.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThe authors did not receive support from any organization for the submitted work.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAU carried out the study design and drafted the manuscript. AU and RK reviewed the manuscript critically, and have read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eData availability\u003c/h2\u003e \u003cp\u003eNot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eChen CJ, Barkovich AJ (1998) A hyperplastic anterior choroidal artery with double persistent anastomotic channels. AJNR Am J Neuroradiol 19:1758\u0026ndash;1760\u003c/li\u003e\n\u003cli\u003eCoulier B (2018) Duplication of the posterior cerebral artery (PCA) or \"true fetal PCA\": an extremely rare variant. J Belg Soc Radiol 102:29. doi: 10.5334/jbsr.1502\u003c/li\u003e\n\u003cli\u003eEndo H, Ono H, Asayama B, Nakamura H (2023) Extremely long posterior cerebral artery P1 segment. Surg Radiol Anat 45:773\u0026ndash;775. doi: 10.1007/s00276-023-03137-4\u003c/li\u003e\n\u003cli\u003eEndo H, Ono H, Nakamura H (2023) Complete duplication of the posterior cerebral artery. Surg Radiol Anat 45:359\u0026ndash;361. doi: 10.1007/s00276-023-03095-x\u003c/li\u003e\n\u003cli\u003eKaplanoglu H, Turan A, Kaplanoglu V, Karacif O (2020) Fetal posterior cerebral artery duplication, true fetal posterior cerebral artery variation and trifurcation anterior cerebral artery association. Surg Radiol Anat 42:1267\u0026ndash;1270. doi: 10.1007/s00276-020-02523-6\u003c/li\u003e\n\u003cli\u003eMasoud H, Nguyen TN, Thatcher J, Barest G, Norbash AM. (2015) Duplication of the posterior cerebral artery and the 'true fetal' variant. Interv Neurol 4:64\u0026ndash;67. doi: 10.1159/000437310\u003c/li\u003e\n\u003cli\u003eMatsuda M, Uchino A, Saito N, Neki H, Kohyama S, Yamane F (2017) Duplicate origin and extremely long P1 segment of the posterior cerebral artery diagnosed by MR angiography. Surg Radiol Anat 39:699\u0026ndash;702. doi: 10.1007/s00276-016-1769-8\u003c/li\u003e\n\u003cli\u003eUchino A, Saito N, Takahashi M, Okano N, Tanisaka M (2016) Variations of the posterior cerebral artery diagnosed by MR angiography at 3 tesla. Neuroradiology 58:141\u0026ndash;146. doi: 10.1007/s00234-015-1614-5\u003c/li\u003e\n\u003cli\u003eUchino A, Suzuki C, Tanaka M (2015) Extremely long posterior communicating artery diagnosed by MR angiography: report of two cases. Surg Radiol Anat 37:565\u0026ndash;568. doi: 10.1007/s00276-014-1413-4\u003c/li\u003e\n\u003cli\u003eUchino A, Tokushige K (2024) Posterior cerebral artery (PCA)-accessory PCA (hyperplastic anterior choroidal artery) anastomosis detected on magnetic resonance angiography. Surg Radiol Anat 46:679\u0026ndash;683. doi: 10.1007/s00276-024-03350-9\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Anastomosis, Anterior choroidal artery, Cerebral arterial variations, Magnetic resonance angiography, Posterior cerebral artery, Posterior communicating artery","lastPublishedDoi":"10.21203/rs.3.rs-5883848/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5883848/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eTo describe a case of double anastomoses between the posterior cerebral artery (PCA) and the posterior communicating artery (PCoA).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eAn 83-year-old woman with left pulsatile tinnitus underwent cranial magnetic resonance angiography (MRA) using a 3-Tesla scanner. MRA was performed using a standard 3-dimensional time-of-flight technique.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eMRA showed no dural arteriovenous fistula; however, there was a stenotic lesion in the precavernous segment of the left internal carotid artery (ICA). This lesion was considered to be the cause of her symptoms. In addition, the left PCA arose from the basilar artery and the left ICA. There was a small connecting artery between these two PCAs at their proximal segments. These two PCAs fused distally and formed a single PCA. Partial maximum intensity projection (MIP) images showed that the left anterior choroidal artery (AChA) appeared normal. Thus, we concluded that there was no hyperplastic AChA, and there were double anastomoses between the left PCA and PCoA.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eWe diagnosed the first case of double anastomosis between the PCA and the PCoA. Careful observation using MRA is important for the detection of rare arterial variations. Partial MIP MRA images are useful for identifying tiny arteries, such as the AChA.\u003c/p\u003e","manuscriptTitle":"Double anastomoses between posterior cerebral artery and posterior communicating artery diagnosed by magnetic resonance angiography","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-03 09:03:52","doi":"10.21203/rs.3.rs-5883848/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-02-12T21:05:06+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-12T16:25:15+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-12T04:00:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-10T09:01:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"803948222945295218421949546159427155","date":"2025-02-06T01:00:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"190032393607601485019097979924076253250","date":"2025-02-03T22:28:50+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-02T04:07:19+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"111723337437535376720958417947657962665","date":"2025-02-02T02:23:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"90877766134508558192278980512938176736","date":"2025-02-02T00:48:51+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-02-01T04:23:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"171927978353624977069644167099746726890","date":"2025-01-26T22:48:47+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-01-23T21:09:58+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-23T15:43:52+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-01-23T12:09:12+00:00","index":"","fulltext":""},{"type":"submitted","content":"Surgical and Radiologic Anatomy","date":"2025-01-22T22:36:16+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"surgical-and-radiologic-anatomy","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"sara","sideBox":"Learn more about [Surgical and Radiologic Anatomy](http://link.springer.com/journal/276)","snPcode":"276","submissionUrl":"https://submission.nature.com/new-submission/276/3","title":"Surgical and Radiologic Anatomy","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"59514b13-280a-41af-a43f-5ac7a3f1ca97","owner":[],"postedDate":"February 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-03-17T16:06:40+00:00","versionOfRecord":{"articleIdentity":"rs-5883848","link":"https://doi.org/10.1007/s00276-025-03603-1","journal":{"identity":"surgical-and-radiologic-anatomy","isVorOnly":false,"title":"Surgical and Radiologic Anatomy"},"publishedOn":"2025-03-11 15:57:33","publishedOnDateReadable":"March 11th, 2025"},"versionCreatedAt":"2025-02-03 09:03:52","video":"","vorDoi":"10.1007/s00276-025-03603-1","vorDoiUrl":"https://doi.org/10.1007/s00276-025-03603-1","workflowStages":[]},"version":"v1","identity":"rs-5883848","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5883848","identity":"rs-5883848","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}