, Volume 48, Issue 9, pp 685–690 | Cite as

Regional cerebral blood flow levels as measured by xenon-CT in vascular territorial low-density areas after subarachnoid hemorrhage are not always ischemic

  • E. FainardiEmail author
  • M. F. Tagliaferri
  • C. Compagnone
  • A. Tanfani
  • F. Cocciolo
  • R. Battaglia
  • M. Frattarelli
  • R. Pascarella
  • L. Targa
  • A. Chieregato
Functional Neuroradiology



The aim of this study was to assess regional cerebral blood flow (rCBV) in areas of CT hypoattenuation appearing in the postoperative period in patients treated for aneurysmal subarachnoid hemorrhage (SAH) using xenon-enhanced CT scanning (Xe-CT).


We analyzed 15 patients (5 male and 10 female; mean age 49.7±12.1 years) with SAH on CT performed on admission to hospital and who showed a low-density area within a well-defined vascular territory on CT scans after clipping or coiling of a saccular aneurysm. All zones of hypoattenuation were larger than 1 cm2 and showed signs of a mass effect suggesting a subacute phase of evolution. Two aneurysms were detected in two patients. Aneurysms were located in the middle cerebral artery (n=7), in the anterior communicating artery (n=6), in the internal carotid artery (n=3), and in the posterior communicating artery (n=1). Treatments were surgical (n=8), endovascular (n=2) or both (n=1). A total of 36 Xe-CT studies were performed and rCBF values were measured in two different regions of interest (ROI): the low-density area, and an area of normal-appearing brain tissue located symmetrically in the contralateral hemisphere.


rCBF levels were significantly lower in the low-density area than in the contralateral normal-appearing area (P<0.01). In the low-density areas, irreversible ischemia (CBF <10 ml/100 g per minute) was present in 11/36 lesions (30.6%), ischemic penumbra (CBF 10–20 ml/100 g per minute) and oligemia (CBF 20–34 ml/100 g per minute) in 8/36 lesions (22.2%), relative hyperemia (CBF 34–55 ml/100 g per minute) in 7/36 lesions (19.4%), and absolute hyperemia (CBF >55 ml/100 g per minute) in 2/36 lesions (5.6%).


Our study confirmed that rCBF is reduced in new low-density lesions related to specific vascular territories. However, only about one-third of the lesions showed rCBF levels consistent with irreversible ischemia and in a relatively high proportion of lesions, rCBF levels indicated penumbral, oligemic and hyperemic areas.


Subarachnoid hemorrhage CT hypodense areas Cerebral blood flow Xenon-CT 


Conflict of interest statement

We declare that we have no conflict of interest.


  1. 1.
    Qureshi AI, Luft AR, Sharma M, Guterman LR, Hopkins LN (2000) Prevention and treatment of thromboembolic and ischemic complications associated with endovascular procedures. Part II – clinical aspects and recommendations. Neurosurgery 46:1360–1376PubMedCrossRefGoogle Scholar
  2. 2.
    Fridriksson S, Säveland H, Jakobsson K-E, Edner G, Zygmunt S, Brandt L, Hillman J (2002) Intraoperative complications in aneurysm surgery: a prospective national study. J Neurosurg 96:515–522PubMedGoogle Scholar
  3. 3.
    Weir B, Macdonald RL, Stoodley M (1999) Etiology of cerebral vasospasm. Acta Neurochir Suppl 72:27–46PubMedGoogle Scholar
  4. 4.
    Mayberg MR, Batjer HH, Dacey R, Diringer M, Haley EC, Heros RC, Sternau LL, Torner J, Adams HP Jr, Feinberg W, Thies W (1994) Guidelines for the management of aneurysmal subarachnoid hemorrhage. A statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. Circulation 90:2592–2605PubMedGoogle Scholar
  5. 5.
    von Kummer R, Bourquain H, Bastianello S, Bozzao L, Manelfe C, Meier D, Hacke W (2001) Early prediction of irreversible brain damage after ischemic stoke at CT. Radiology 219:95–100Google Scholar
  6. 6.
    Inoue Y, Takemoto K, Miyamoto T, Yoshikawa N, Taniguchi S, Saiwai S, Nishimura Y, Komatsu T (1980) Sequential computed tomography scans in acute cerebral infarction. Radiology 135:655–662PubMedGoogle Scholar
  7. 7.
    Latchaw RE, Yonas H, Hunter GJ, Yuh WTC, Ueda T, Sorensen AG, Sunshine JL, Biller J, Wechsler L, Higashida R, Hademenos G (2003) Guidelines and recommendations for perfusion imaging in cerebral ischemia. A Scientific Statement for Healthcare Professionals by the Writing Group on Perfusion Imaging, from the Council on Cardiovascular Radiology of the American Heart Association. Stroke 34:1064–1104CrossRefGoogle Scholar
  8. 8.
    Kaufmann AM, Firlik AD, Fukui MB, Wechsler LR, Jungries CA, Yonas H (1999) Ischemic core and penumbra in human stroke. Stroke 30:93–99PubMedGoogle Scholar
  9. 9.
    Jovin TG, Yonas H, Gebel JM, Kanal E, Chang YF, Grahovac SZ, Goldstein S, Wechsler LR (2003) The cortical ischemic core and not the consistently present penumbra is a determinant of clinical outcome in acute middle cerebral artery occlusion. Stroke 34:2426–2435PubMedCrossRefGoogle Scholar
  10. 10.
    Yonas H, Sekhar L, Johnson DW, Gur D (1989) Determination of irreversible ischemia by xenon-enhanced computed tomography monitoring of cerebral blood flow in patients with symptomatic vasospasm. Neurosurgery 24:368–372PubMedCrossRefGoogle Scholar
  11. 11.
    Fukui MB, Johnson DW, Yonas H, Sekhar L, Latchaw RE, Pentheny S (1992) Xe/CT cerebral blood flow evaluation of delayed symptomatic cerebral ischemia after subarachnoid hemorrhage. AJNR Am J Neuroradiol 13:265–270PubMedGoogle Scholar
  12. 12.
    Darby JM, Yonas H, Marks EC, Durham S, Snyder RW, Nemoto EM (1994) Acute cerebral blood flow response to dopamine-induced hypertension after subarachnoid hemorrhage. J Neurosurg 80:857–864PubMedGoogle Scholar
  13. 13.
    Clyde BL, Resnick DK, Yonas H, Smith HA, Kaufmann AM (1996) The relationship of blood velocity as measured by transcranial doppler ultrasonography to cerebral blood flow as determined by stable xenon computed tomographic studies after aneurysmal subarachnoid hemorrhage. Neurosurgery 38:896–905PubMedCrossRefGoogle Scholar
  14. 14.
    Kim DH, Joseph M, Ziadi S, Nates J, Dannenbaum M, Malkoff M (2003) Increases in cardiac output function can reverse flow deficits from vasospasm independent of blood pressure: a study using xenon computed tomographic measurement of cerebral blood flow. Neurosurgery 53:1044–1052CrossRefGoogle Scholar
  15. 15.
    Vajkoczy P, Horn P, Thome C, Munch E, Schmiedek P (2003) Regional cerebral blood flow monitoring in the diagnosis of delayed ischemia following aneurysmal subarachnoid hemorrhage. J Neurosurg 98:1227–1234PubMedGoogle Scholar
  16. 16.
    Fisher CM, Kistler JP, Davis JM (1980) Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by computerized tomographic scanning. Neurosurgery 6:1–9PubMedCrossRefGoogle Scholar
  17. 17.
    Wardlaw J, Sellar R (1994) A simple practical classification of cerebral infarcts on CT and its interobserver reliability. AJNR Am J Neuroradiol 15:1933–1939PubMedGoogle Scholar
  18. 18.
    Hunt W, Hess R (1968) Surgical risk as related to time of intervention in the repair of intracranial aneurysms. J Neurosurg 28:14–20PubMedGoogle Scholar
  19. 19.
    Pindzola RR, Yonas H (1998) The xenon-enhanced computed tomography cerebral blood flow method. Neurosurgery 43:1488–1492PubMedCrossRefGoogle Scholar
  20. 20.
    Jones TH, Morawetz RB, Crowell RM, Marcoux FW, Fitz Gibbon SJ, DeGirolami U, Ojemann RG (1981) Thresholds of focal cerebral ischemia in awake monkeys. J Neurosurg 54:773–782PubMedCrossRefGoogle Scholar
  21. 21.
    Obrist WD, Langfitt TW, Jaggi JL, Cruz J, Gennarelli TA (1984) Cerebral blood flow and metabolism in comatose patients with acute injury. Relationship to intracranial hypertension. J Neurosurg 61:241–253PubMedCrossRefGoogle Scholar
  22. 22.
    Heiss W-D (2000) Ischemic penumbra: evidence from functional imaging in man. J Cereb Blood Flow Metab 20:1276–1293PubMedCrossRefGoogle Scholar
  23. 23.
    Rieth KG, Fujiwara K, Di Chiro G, Klatzo I, Brooks RA, Johnston GS, O’Connor CM, Mitchell LG (1980) Serial measurements of CT attenuation and specific gravity in experimental cerebral edema. Radiology 135:343–348PubMedGoogle Scholar
  24. 24.
    Knuckey NW, Fox RA, Surveyor I, Stokes BAR (1985) Early cerebral blood flow and computerized tomography in predicting ischemia after cerebral aneurysm rupture. J Neurosurg 62:850–855PubMedCrossRefGoogle Scholar
  25. 25.
    Marchal G, Young AR, Baron J-C (1999) Early postischemic hyperperfusion: pathophysiologic insights from positron emission tomography. J Cereb Blood Flow Metab 19:467–482PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • E. Fainardi
    • 1
    Email author
  • M. F. Tagliaferri
    • 2
  • C. Compagnone
    • 2
  • A. Tanfani
    • 2
  • F. Cocciolo
    • 2
  • R. Battaglia
    • 3
  • M. Frattarelli
    • 3
  • R. Pascarella
    • 4
  • L. Targa
    • 2
  • A. Chieregato
    • 2
  1. 1.Neuroradiology Unit, Department of NeurosciencesArcispedale S. AnnaFerraraItaly
  2. 2.Neurocritical Care UnitOspedale M. BufaliniCesenaItaly
  3. 3.Neurosurgery UnitOspedale M. BufaliniCesenaItaly
  4. 4.Neuroradiology UnitOspedale M. BufaliniCesenaItaly

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