Multimodality PET/CT and MRI Evaluation of a Parasagittal Parietal Brain Lesion: Broad Differential Diagnostic Considerations

Multimodality PET/CT and MRI Evaluation of a Parasagittal Parietal Brain Lesion: Broad Differential Diagnostic Considerations | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Multimodality PET/CT and MRI Evaluation of a Parasagittal Parietal Brain Lesion: Broad Differential Diagnostic Considerations ayesha ammar This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9405625/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Parasagittal parietal lesions present a diagnostic challenge due to overlapping radiological features among dural-based and cortical pathologies. Integration of anatomical and functional imaging can aid in refining the differential diagnosis. Case Presentation: We report the case of a 19 year old patient presenting with persistent headache. Contrast-enhanced magnetic resonance imaging (CE-MRI) revealed a heterogeneously enhancing parasagittal parietal lesion with associated mass effect. FDG PET/CT demonstrated marked metabolic uptake, while Gallium-68 PET/CT revealed concordant uptake, suggesting somatostatin receptor expression. The differential diagnosis included hemangiopericytoma, meningioma, parafalcine oligodendroglioma, cortical glioma, and dural metastases. Conclusion This case emphasizes the importance of a multimodality approach, combining MRI with both FDG and Ga-68 PET/CT, in characterizing complex intracranial lesions and narrowing the differential diagnosis prior to histopathological confirmation. Nuclear Medicine & Medical Imaging Parasagittal parietal lesion FDG PET/CT Gallium-68 PET/CT meningioma hemangiopericytoma oligodendroglioma dural metastases brain tumor imaging Introduction Intracranial parasagittal lesions encompass a spectrum of neoplastic and non-neoplastic etiologies. While MRI provides superior anatomical delineation, metabolic imaging with positron emission tomography (PET) can yield complementary information regarding tumor metabolism and receptor expression. FDG PET/CT is widely utilized to assess glycolytic activity, whereas Ga-68 DOTATATE PET/CT offers high sensitivity for somatostatin receptor–expressing tumors such as meningiomas and hemangiopericytomas. When lesions exhibit atypical enhancement patterns, integration of both imaging modalities can aid in surgical planning and guide biopsy strategies. Case Presentation A 19 year-old patient presented with a 2-month history of intermittent headaches, progressively increasing in severity. There was no history of seizures, focal neurological deficits, or systemic illness. Neurological examination was unremarkable. MRI Findings Contrast Enhanced MRI revealed a well-circumscribed, heterogeneously enhancing lesion in the parasagittal parietal region, causing mild midline shift and adjacent cortical compression. The lesion appeared dural-based with broad dural contact and mass effect on the superior sagittal sinus. No calcification or hemorrhage was identified on susceptibility-weighted imaging. FDG PET/CT PET CT scan showed FDG avid central necrotic hetrogenosuly enhancing lesion dural based lobulated lesion in the parafalcin location in the left parietal region, causing mild scalloping of left parietal bone having (SUV max 8.4, 3.2*27.7cm) versus normal brain (SUV max 6.02). Significant perilesional edema not causing hydrocephalous however it is causing effacement of adjacent cortical sulci compression of the ipsilateral ventricle and a mid line shift towards the right side, with no evidence of extracranial primary malignancy or systemic metastases. Ga-68 PET/CT The lesion showed concordant uptake on Ga-68 DOTATATE imaging, indicating possible somatostatin receptor overexpression. The patient underwent surgical excision. Histopathology confirmed an anaplastic meningioma (WHO Grade III). Discussion The imaging findings in this case—a parasagittal lesion in the parietal region with both FDG and Ga-68 uptake—prompt a multifaceted differential diagnosis. Integrating MRI morphologic details with metabolic and receptor-based PET imaging enhances diagnostic precision. 1. Hemangiopericytoma (HPC): An aggressive dural-based neoplasm originating from pericytes. HPCs often mimic meningiomas on MRI but tend to exhibit more heterogeneous enhancement and minimal calcifications. On FDG PET-CT, HPCs demonstrate high glycolytic activity, while Ga-68 DOTATATE uptake is commonly noted due to somatostatin receptor expression (Rutkowski et al., 2010; Rachinger et al., 2010) [ 1 , 7 ] 2. Meningioma: The most prevalent dural-based brain tumor, typically demonstrating strong and homogeneous enhancement on MRI, often with a visible “dural tail.” Although generally benign, atypical or high-grade subtypes may appear heterogeneous radiologically. Ga-68 uptake is well-documented in meningiomas owing to somatostatin receptor overexpression (Rachinger et al., 2015; Louis et al., 2021)[ 2 , 3 ] 3. Parafalcine Oligodendroglioma: A rare glioma arising near the falx, potentially simulating dural-based lesions. Imaging may reveal calcifications and cortical infiltration. 4. FDG uptake tends to be similar to white matter unless high-grade, with amino acid tracers like 11C-methionine providing more specificity (Radiopaedia; Imaging review) [ 11 ] 5. Cortical Glioma: Primary intra-axial lesions that may abut the dura and complicate differentiation from dural-based tumors. FDG uptake varies depending on tumor grade and overlaps with gray matter baseline activity, lowering sensitivity (Imaging literature on gliomas and oligodendrogliomas) 6. Dural Metastases: Secondary neoplastic involvement of the dura, commonly associated with systemic malignancies (e.g., breast, lung, prostate). On imaging, these lesions often enhance heterogeneously and show high FDG uptake reflective of their aggressive nature. While FDG PET-CT can identify metabolic activity, Ga-68 is not typically taken up unless the metastasis expresses the relevant receptors (Bone metastases imaging examples, general PET/CT literature) [ 6 ] Meningiomas represent ~ 30% of adult primary intracranial tumors, with anaplastic variants (Grade III) accounting for < 3% and associated with aggressive clinical course, recurrence, and poor prognosis (Louis et al., 2021).[ 3 ] Imaging challenges. On MRI, high-grade meningiomas often mimic hemangiopericytomas, gliomas, or dural metastases, complicating diagnosis (Zhou et al., 2016).[ 12 ] FDG PET/CT provides metabolic information; high-grade meningiomas typically demonstrate increased FDG uptake, correlating with proliferation and aggressiveness (Cornelius et al., 2012). [ 8 ]. However, background cortical uptake may reduce specificity. Ga-68 PET/CT with somatostatin analogs (DOTATATE, DOTATOC, DOTANOC) provides high lesion-to-background contrast due to overexpression of SSTR2 in meningiomas (Henze et al., 2001). It has proven value in pre-surgical mapping, radiotherapy planning, and selection for PRRT (Afshar-Oromieh et al., 2012; Ivanidze et al., 2019).[ 9 , 10 ] Dual-tracer approach. FDG uptake reflects metabolic aggressiveness, while Ga-68 uptake reflects receptor density and therapeutic potential. In our case, concordant FDG and Ga-68 uptake suggested high-grade biology, later confirmed histopathologically. This dual-tracer correlation is rarely reported in anaplastic meningiomas and may represent an imaging biomarker for disease stratification.[ 4 , 5 ] Supporting literature. Our case underscores the synergistic role of dual-tracer PET/CT in both diagnosis and therapeutic planning of aggressive meningiomas. FDG PET-CT captures metabolic activity and is particularly useful for high-grade tumors or metastases, though intracranial uptake must be interpreted cautiously due to physiologic gray matter activity (FDG-PET limitations in brain metastases) Ga-68 DOTATATE PET-CT serves as a receptor-based modality, sensitive to somatostatin receptor–positive lesions, thus helping differentiate meningioma or HPC from gliomas or metastases WikipediaRadiopaedia. The concurrent uptake on both imaging modalities in our case significantly increases the likelihood of a perfused, receptor-positive extracerebral mass such as meningioma or HPC. Nevertheless, histopathological confirmation remains essential, as imaging, though highly informative, cannot definitively distinguish between these entities. Declarations Patient Consent Written informed consent was obtained from the patient for publication of this case report and accompanying images. References Rutkowski MJ et al (2010) Hemangiopericytoma: a review of clinical, imaging, and histopathological features. Neurosurg Focus 29(3):E9 Rachinger W et al (2015) Positron emission tomography with [68Ga]DOTATATE for meningioma imaging. Neurosurgery 77(3):390–397 Louis DN et al (2021) WHO Classification of Tumours of the Central Nervous System, 5th Edition. Lyon: IARC Lopes MB et al (2012) Oligodendrogliomas: an update on pathology and molecular markers. Histol Histopathol 27(2):229–241 Chamberlain MC et al (2005) Dural metastases. Cancer 103(11):2315–2324 Zhang M et al (2020) The role of PET in intracranial tumors: differential diagnosis and clinical management. Eur J Radiol 129:109136 Rachinger W et al (2010) Increased somatostatin receptor expression in atypical and malignant meningiomas. J Neurooncol 96(3):325–332 Cornelius JF et al (2013) 68Ga-DOTATOC PET/CT for preoperative meningioma grading. Clin Nucl Med 38(1):e26–e29 Ivanidze et al (2019) confirmed the value of Ga-68 PET/CT in delineating meningiomas for surgical and radiation planning Afshar-Oromieh et al (2012) reported superior sensitivity of Ga-68 tracers compared with MRI for detecting meningiomas Source Radiopaedia Zhou J, Zhao R, Pan Y, Ju H, Huang X, Jiang Y, Jin J, Zhang Y (2022) The Diagnostic and Grading Accuracy of 68Ga-DOTATATE and 18F-FDG PET/MR for Pancreatic Neuroendocrine Neoplasms. Front Oncol 12:796391 Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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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-9405625","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":622390674,"identity":"2ae58cfd-b916-475b-a329-b67c0cc94ffd","order_by":0,"name":"ayesha ammar","email":"data:image/png;base64,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","orcid":"","institution":"nori","correspondingAuthor":true,"prefix":"","firstName":"ayesha","middleName":"","lastName":"ammar","suffix":""}],"badges":[],"createdAt":"2026-04-13 14:47:05","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-9405625/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9405625/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106856327,"identity":"15be5361-8bee-4bc8-887d-74abeb608528","added_by":"auto","created_at":"2026-04-14 07:28:56","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":458818,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9405625/v1/c1e3eb71-1a3c-4bc0-9a48-957d66d3a63a.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eMultimodality PET/CT and MRI Evaluation of a Parasagittal Parietal Brain Lesion: Broad Differential Diagnostic Considerations\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eIntracranial parasagittal lesions encompass a spectrum of neoplastic and non-neoplastic etiologies. While MRI provides superior anatomical delineation, metabolic imaging with positron emission tomography (PET) can yield complementary information regarding tumor metabolism and receptor expression. FDG PET/CT is widely utilized to assess glycolytic activity, whereas Ga-68 DOTATATE PET/CT offers high sensitivity for somatostatin receptor\u0026ndash;expressing tumors such as meningiomas and hemangiopericytomas. When lesions exhibit atypical enhancement patterns, integration of both imaging modalities can aid in surgical planning and guide biopsy strategies.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eA 19 year-old patient presented with a 2-month history of intermittent headaches, progressively increasing in severity. There was no history of seizures, focal neurological deficits, or systemic illness. Neurological examination was unremarkable.\u003c/p\u003e \u003cp\u003e \u003cstrong\u003eMRI Findings\u003c/strong\u003e \u003cp\u003eContrast Enhanced MRI revealed a well-circumscribed, heterogeneously enhancing lesion in the parasagittal parietal region, causing mild midline shift and adjacent cortical compression. The lesion appeared dural-based with broad dural contact and mass effect on the superior sagittal sinus. No calcification or hemorrhage was identified on susceptibility-weighted imaging.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eFDG PET/CT\u003c/strong\u003e \u003cp\u003ePET CT scan showed FDG avid central necrotic hetrogenosuly enhancing lesion dural based lobulated lesion in the parafalcin location in the left parietal region, causing mild scalloping of left parietal bone having (SUV max 8.4, 3.2*27.7cm) versus normal brain (SUV max 6.02). Significant perilesional edema not causing hydrocephalous however it is causing effacement of adjacent cortical sulci compression of the ipsilateral ventricle and a mid line shift towards the right side, with no evidence of extracranial primary malignancy or systemic metastases.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eGa-68 PET/CT\u003c/strong\u003e \u003cp\u003eThe lesion showed concordant uptake on Ga-68 DOTATATE imaging, indicating possible somatostatin receptor overexpression.\u003c/p\u003e \u003c/p\u003e \u003cp\u003eThe patient underwent surgical excision. \u003cb\u003eHistopathology confirmed an anaplastic meningioma (WHO Grade III).\u003c/b\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe imaging findings in this case\u0026mdash;a parasagittal lesion in the parietal region with both FDG and Ga-68 uptake\u0026mdash;prompt a multifaceted differential diagnosis. Integrating MRI morphologic details with metabolic and receptor-based PET imaging enhances diagnostic precision.\u003c/p\u003e\n\u003ch3\u003e1. Hemangiopericytoma (HPC):\u003c/h3\u003e\n\u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eAn aggressive dural-based neoplasm originating from pericytes. HPCs often mimic meningiomas on MRI but tend to exhibit more heterogeneous enhancement and minimal calcifications.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOn FDG PET-CT, HPCs demonstrate high glycolytic activity, while Ga-68 DOTATATE uptake is commonly noted due to somatostatin receptor expression (Rutkowski et al., 2010; Rachinger et al., 2010) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e\n\u003ch3\u003e2. Meningioma:\u003c/h3\u003e\n\u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eThe most prevalent dural-based brain tumor, typically demonstrating strong and homogeneous enhancement on MRI, often with a visible \u0026ldquo;dural tail.\u0026rdquo; Although generally benign, atypical or high-grade subtypes may appear heterogeneous radiologically.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eGa-68 uptake is well-documented in meningiomas owing to somatostatin receptor overexpression (Rachinger et al., 2015; Louis et al., 2021)[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e\n\u003ch3\u003e3. Parafalcine Oligodendroglioma:\u003c/h3\u003e\n\u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eA rare glioma arising near the falx, potentially simulating dural-based lesions. Imaging may reveal calcifications and cortical infiltration.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003e4. FDG uptake tends to be similar to white matter unless high-grade, with amino acid tracers like 11C-methionine providing more specificity (Radiopaedia; Imaging review) [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e\n\u003ch3\u003e5. Cortical Glioma:\u003c/h3\u003e\n\u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003ePrimary intra-axial lesions that may abut the dura and complicate differentiation from dural-based tumors. FDG uptake varies depending on tumor grade and overlaps with gray matter baseline activity, lowering sensitivity (Imaging literature on gliomas and oligodendrogliomas)\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e6. Dural Metastases:\u003c/h2\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eSecondary neoplastic involvement of the dura, commonly associated with systemic malignancies (e.g., breast, lung, prostate). On imaging, these lesions often enhance heterogeneously and show high FDG uptake reflective of their aggressive nature.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eWhile FDG PET-CT can identify metabolic activity, Ga-68 is not typically taken up unless the metastasis expresses the relevant receptors (Bone metastases imaging examples, general PET/CT literature) [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eMeningiomas represent\u0026thinsp;~\u0026thinsp;30% of adult primary intracranial tumors, with \u003cb\u003eanaplastic variants (Grade III)\u003c/b\u003e accounting for \u0026lt;\u0026thinsp;3% and associated with aggressive clinical course, recurrence, and poor prognosis (Louis et al., 2021).[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/p\u003e \u003cp\u003e \u003cb\u003eImaging challenges.\u003c/b\u003e On MRI, high-grade meningiomas often mimic hemangiopericytomas, gliomas, or dural metastases, complicating diagnosis (Zhou et al., 2016).[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/p\u003e \u003cp\u003e \u003cb\u003eFDG PET/CT\u003c/b\u003e provides metabolic information; high-grade meningiomas typically demonstrate increased FDG uptake, correlating with proliferation and aggressiveness (Cornelius et al., 2012). [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. However, background cortical uptake may reduce specificity.\u003c/p\u003e \u003cp\u003e \u003cb\u003eGa-68 PET/CT\u003c/b\u003e with somatostatin analogs (DOTATATE, DOTATOC, DOTANOC) provides high lesion-to-background contrast due to overexpression of SSTR2 in meningiomas (Henze et al., 2001). It has proven value in pre-surgical mapping, radiotherapy planning, and selection for PRRT (Afshar-Oromieh et al., 2012; Ivanidze et al., 2019).[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/p\u003e \u003cp\u003e \u003cb\u003eDual-tracer approach.\u003c/b\u003e FDG uptake reflects metabolic aggressiveness, while Ga-68 uptake reflects receptor density and therapeutic potential. In our case, \u003cb\u003econcordant FDG and Ga-68 uptake\u003c/b\u003e suggested high-grade biology, later confirmed histopathologically. This dual-tracer correlation is rarely reported in anaplastic meningiomas and may represent an imaging biomarker for disease stratification.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/p\u003e \u003cp\u003e \u003cb\u003eSupporting literature.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eOur case underscores the \u003cb\u003esynergistic role of dual-tracer PET/CT\u003c/b\u003e in both \u003cb\u003ediagnosis and therapeutic planning\u003c/b\u003e of aggressive meningiomas.\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eFDG PET-CT\u003c/b\u003e captures metabolic activity and is particularly useful for high-grade tumors or metastases, though intracranial uptake must be interpreted cautiously due to physiologic gray matter activity (FDG-PET limitations in brain metastases)\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eGa-68 DOTATATE PET-CT\u003c/b\u003e serves as a receptor-based modality, sensitive to somatostatin receptor\u0026ndash;positive lesions, thus helping differentiate meningioma or HPC from gliomas or metastases WikipediaRadiopaedia.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe concurrent uptake on both imaging modalities in our case significantly increases the likelihood of a perfused, receptor-positive extracerebral mass such as meningioma or HPC.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eNevertheless, \u003cb\u003ehistopathological confirmation\u003c/b\u003e remains essential, as imaging, though highly informative, cannot definitively distinguish between these entities.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\n\u003ch3\u003ePatient Consent\u003c/h3\u003e\n\u003cp\u003eWritten informed consent was obtained from the patient for publication of this case report and accompanying images.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eRutkowski MJ et al (2010) Hemangiopericytoma: a review of clinical, imaging, and histopathological features. Neurosurg Focus 29(3):E9\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRachinger W et al (2015) Positron emission tomography with [68Ga]DOTATATE for meningioma imaging. Neurosurgery 77(3):390\u0026ndash;397\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLouis DN et al (2021) WHO Classification of Tumours of the Central Nervous System, 5th Edition. Lyon: IARC\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLopes MB et al (2012) Oligodendrogliomas: an update on pathology and molecular markers. Histol Histopathol 27(2):229\u0026ndash;241\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChamberlain MC et al (2005) Dural metastases. Cancer 103(11):2315\u0026ndash;2324\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang M et al (2020) The role of PET in intracranial tumors: differential diagnosis and clinical management. Eur J Radiol 129:109136\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRachinger W et al (2010) Increased somatostatin receptor expression in atypical and malignant meningiomas. J Neurooncol 96(3):325\u0026ndash;332\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCornelius JF et al (2013) 68Ga-DOTATOC PET/CT for preoperative meningioma grading. Clin Nucl Med 38(1):e26\u0026ndash;e29\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIvanidze et al (2019) confirmed the value of Ga-68 PET/CT in delineating meningiomas for surgical and radiation planning\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAfshar-Oromieh et al (2012) reported superior sensitivity of Ga-68 tracers compared with MRI for detecting meningiomas\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSource Radiopaedia\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhou J, Zhao R, Pan Y, Ju H, Huang X, Jiang Y, Jin J, Zhang Y (2022) The Diagnostic and Grading Accuracy of 68Ga-DOTATATE and 18F-FDG PET/MR for Pancreatic Neuroendocrine Neoplasms. Front Oncol 12:796391\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"atomic energy cancer hospital NORI","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Parasagittal parietal lesion, FDG PET/CT, Gallium-68 PET/CT, meningioma, hemangiopericytoma, oligodendroglioma, dural metastases, brain tumor imaging","lastPublishedDoi":"10.21203/rs.3.rs-9405625/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9405625/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eParasagittal parietal lesions present a diagnostic challenge due to overlapping radiological features among dural-based and cortical pathologies. Integration of anatomical and functional imaging can aid in refining the differential diagnosis.\u003c/p\u003e\u003ch2\u003eCase Presentation:\u003c/h2\u003e \u003cp\u003eWe report the case of a 19 year old patient presenting with persistent headache. Contrast-enhanced magnetic resonance imaging (CE-MRI) revealed a heterogeneously enhancing parasagittal parietal lesion with associated mass effect. FDG PET/CT demonstrated marked metabolic uptake, while Gallium-68 PET/CT revealed concordant uptake, suggesting somatostatin receptor expression. The differential diagnosis included hemangiopericytoma, meningioma, parafalcine oligodendroglioma, cortical glioma, and dural metastases.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThis case emphasizes the importance of a multimodality approach, combining MRI with both FDG and Ga-68 PET/CT, in characterizing complex intracranial lesions and narrowing the differential diagnosis prior to histopathological confirmation.\u003c/p\u003e","manuscriptTitle":"Multimodality PET/CT and MRI Evaluation of a Parasagittal Parietal Brain Lesion: Broad Differential Diagnostic Considerations","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-14 07:26:33","doi":"10.21203/rs.3.rs-9405625/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6e4c6f7a-e580-4557-a2c9-b13666e1c0b3","owner":[],"postedDate":"April 14th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":66231659,"name":"Nuclear Medicine \u0026 Medical Imaging"}],"tags":[],"updatedAt":"2026-04-14T07:26:33+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-14 07:26:33","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9405625","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9405625","identity":"rs-9405625","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}