title: Arterial Spin Labeling Perfusion of the Brain: Emerging Clinical Applications.
abstract: Arterial spin labeling (ASL) is a magnetic resonance (MR) imaging technique used to assess cerebral blood flow noninvasively by magnetically labeling inflowing blood. In this article, the main labeling techniques, notably pulsed and pseudocontinuous ASL, as well as emerging clinical applications will be reviewed. In dementia, the pattern of hypoperfusion on ASL images closely matches the established patterns of hypometabolism on fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) images due to the close coupling of perfusion and metabolism in the brain. This suggests that ASL might be considered as an alternative for FDG, reserving PET to be used for the molecular disease-specific amyloid and tau tracers. In stroke, ASL can be used to assess perfusion alterations both in the acute and the chronic phase. In arteriovenous malformations and dural arteriovenous fistulas, ASL is very sensitive to detect even small degrees of shunting. In epilepsy, ASL can be used to assess the epileptogenic focus, both in peri- and interictal period. In neoplasms, ASL is of particular interest in cases in which gadolinium-based perfusion is contraindicated (eg, allergy, renal impairment) and holds promise in differentiating tumor progression from benign causes of enhancement. Finally, various neurologic and psychiatric diseases including mild traumatic brain injury or posttraumatic stress disorder display alterations on ASL images in the absence of visualized structural changes. In the final part, current limitations and future developments of ASL techniques to improve clinical applicability, such as multiple inversion time ASL sequences to assess alterations of transit time, reproducibility and quantification of cerebral blood flow, and to measure cerebrovascular reserve, will be reviewed.©RSNA, 2016 Online supplemental material is available for this article.
authors.affiliation: From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.).
authors.forename: Sven
authors.initials: S
authors.lastname: Haller
authors.affiliation: From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.).
authors.forename: Greg
authors.initials: G
authors.lastname: Zaharchuk
authors.affiliation: From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.).
authors.forename: David L
authors.initials: DL
authors.lastname: Thomas
authors.affiliation: From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.).
authors.forename: Karl-Olof
authors.initials: KO
authors.lastname: Lovblad
authors.affiliation: From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.).
authors.forename: Frederik
authors.initials: F
authors.lastname: Barkhof
authors.affiliation: From Affidea Centre Diagnostique Radiologique de Carouge, Clos de la Fonderie 1, 1227 Carouge, Switzerland (S.H.); Dept of Surgical Sciences, Div of Radiology, Uppsala Univ, Sweden (S.H.); Dept of Neuroradiology, Univ Hosp Freiburg, Germany (S.H.); Faculty of Medicine Univ of Geneva, Switzerland (S.H.); Dept of Radiology, Stanford Univ, Stanford, Calif (G.Z.); Univ College London, Inst of Neurology, London, England (D.L.T., X.G.); Dept of Diagnostic and Interventional Neuroradiology, Geneva Univ Hosps,Switzerland (K.O.L.); Dept of Radiology & Nuclear Medicine and PET Research, VU Univ Medical Ctr, Amsterdam, the Netherlands (F.B.); and Insts of Neurology and Healthcare Engineering, Univ College London, England (F.B.).
authors.forename: Xavier
authors.initials: X
authors.lastname: Golay
mesh_terms: D001783:Blood Flow Velocity; D001810:Blood Volume; D001927:Brain Diseases / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D059906:Neuroimaging / Q000379:methods*; D013113:Spin Labels
chemical_list: D013113:Spin Labels