Published Online:

Dual-energy CT has high sensitivity and specificity in the differentiation of intraparenchymal hemorrhage from iodinated contrast material staining and may be particularly helpful in patients who have recently undergone intraarterial stroke therapy.


To evaluate the efficacy of dual-energy computed tomography (CT) in the differentiation of intracerebral hemorrhage (ICH) from iodinated contrast material in patients who received contrast material via intraarterial or intravenous delivery.

Materials and Methods

This retrospective study was approved by the local institutional review board, which waived the informed consent requirement for the analysis. Sixteen patients with acute stroke and two with head trauma who had undergone intraarterial or intravenous administration of iodinated contrast material were evaluated by using dual-energy CT to differentiate areas of hyperattenuation secondary to contrast material staining from those representing ICH. A dual-energy CT scanner was used for imaging at 80 and 140 kV, and a three-material decomposition algorithm was used to obtain virtual unenhanced images and iodine overlay images. The sensitivity, specificity, and accuracy of dual-energy CT in the prospective differentiation of intraparenchymal contrast material from hemorrhage were obtained. Follow-up images were used as the standard of reference.


There were 28 intraparenchymal areas of hyperattenuation classified at dual-energy CT as iodinated contrast material staining (n = 20, 71%), hemorrhage (n = 5, 18%), or both (n = 3, 11%). Two of the three areas of hyperattenuation seen on both virtual unenhanced and iodine overlay images were related to mineralization. The sensitivity, specificity, and accuracy of dual-energy CT in the identification of hemorrhage were 100% (six of six areas), 91% (20 of 22 areas), and 93% (26 of 28 areas), respectively.


Dual-energy CT can help differentiate ICH from iodinated contrast material staining with high sensitivity and specificity in patients who have recently received intraarterial or intravenous iodinated contrast material.

© RSNA, 2010


  • 1 Tissue plasminogen activator for acute ischemic stroke. The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. N Engl J Med 1995;333(24):1581–1587. Crossref, MedlineGoogle Scholar
  • 2 Furlan A, Higashida R, Wechsler L, et al.. Intra-arterial prourokinase for acute ischemic stroke: the PROACT II study—a randomized controlled trial. Prolyse in Acute Cerebral Thromboembolism. JAMA 1999;282(21):2003–2011. Crossref, MedlineGoogle Scholar
  • 3 Rha JH, Saver JL. The impact of recanalization on ischemic stroke outcome: a meta-analysis. Stroke 2007;38(3):967–973. Crossref, MedlineGoogle Scholar
  • 4 Smith WS, Sung G, Saver J, et al.. Mechanical thrombectomy for acute ischemic stroke: final results of the Multi MERCI trial. Stroke 2008;39(4):1205–1212. Crossref, MedlineGoogle Scholar
  • 5 Lees KR, Zivin JA, Ashwood T, et al.. NXY-059 for acute ischemic stroke. N Engl J Med 2006;354(6):588–600. Crossref, MedlineGoogle Scholar
  • 6 Berger C, Fiorelli M, Steiner T, et al.. Hemorrhagic transformation of ischemic brain tissue: asymptomatic or symptomatic? Stroke 2001;32(6):1330–1335. Crossref, MedlineGoogle Scholar
  • 7 Khatri P, Wechsler LR, Broderick JP. Intracranial hemorrhage associated with revascularization therapies. Stroke 2007;38(2):431–440. Crossref, MedlineGoogle Scholar
  • 8 IMS Study Investigators. Combined intravenous and intra-arterial recanalization for acute ischemic stroke: the Interventional Management of Stroke Study. Stroke 2004;35(4):904–911. Crossref, MedlineGoogle Scholar
  • 9 Jang YM, Lee DH, Kim HS, et al.. The fate of high-density lesions on the non-contrast CT obtained immediately after intra-arterial thrombolysis in ischemic stroke patients. Korean J Radiol 2006;7(4):221–228. Crossref, MedlineGoogle Scholar
  • 10 Greer DM, Koroshetz WJ, Cullen S, Gonzalez RG, Lev MH. Magnetic resonance imaging improves detection of intracerebral hemorrhage over computed tomography after intra-arterial thrombolysis. Stroke 2004;35(2):491–495. Crossref, MedlineGoogle Scholar
  • 11 Intracerebral hemorrhage after intravenous t-PA therapy for ischemic stroke. The NINDS t-PA Stroke Study Group. Stroke 1997;28(11):2109–2118. Crossref, MedlineGoogle Scholar
  • 12 Technology Assessment Committees of the American Society of Interventional and Therapeutic Neuroradiology; Society of Interventional Radiology. Trial design and reporting standards for intraarterial cerebral thrombolysis for acute ischemic stroke. 2003. J Vasc Interv Radiol 2003;14(8):945–946. MedlineGoogle Scholar
  • 13 Leigh R, Zaidat OO, Suri MF, et al.. Predictors of hyperacute clinical worsening in ischemic stroke patients receiving thrombolytic therapy. Stroke 2004;35(8):1903–1907. Crossref, MedlineGoogle Scholar
  • 14 Yoon W, Seo JJ, Kim JK, Cho KH, Park JG, Kang HK. Contrast enhancement and contrast extravasation on computed tomography after intra-arterial thrombolysis in patients with acute ischemic stroke. Stroke 2004;35(4):876–881. Crossref, MedlineGoogle Scholar
  • 15 Johnson TR, Nikolaou K, Wintersperger BJ, et al.. Dual-source CT cardiac imaging: initial experience. Eur Radiol 2006;16(7):1409–1415. Crossref, MedlineGoogle Scholar
  • 16 Petersilka M, Bruder H, Krauss B, Stierstorfer K, Flohr TG. Technical principles of dual source CT. Eur J Radiol 2008;68(3):362–368. Crossref, MedlineGoogle Scholar
  • 17 Mericle RA, Lopes DK, Fronckowiak MD, Wakhloo AK, Guterman LR, Hopkins LN. A grading scale to predict outcomes after intra-arterial thrombolysis for stroke complicated by contrast extravasation. Neurosurgery 2000;46(6):1307–1314, discussion 1314–1315. Crossref, MedlineGoogle Scholar
  • 18 Nakano S, Iseda T, Yoneyama T, Wakisaka S. Early CT signs in patients with acute middle cerebral artery occlusion: incidence of contrast staining and haemorrhagic transformations after intra-arterial reperfusion therapy. Clin Radiol 2006;61(2):156–162. Crossref, MedlineGoogle Scholar
  • 19 Paciaroni M, Agnelli G, Corea F, et al.. Early hemorrhagic transformation of brain infarction: rate, predictive factors, and influence on clinical outcome: results of a prospective multicenter study. Stroke 2008;39(8):2249–2256. Crossref, MedlineGoogle Scholar
  • 20 Adams HP, del Zoppo G, Alberts MJ, et al.. Guidelines for the early management of adults with ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council, Clinical Cardiology Council, Cardiovascular Radiology and Intervention Council, and the Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups: The American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists. Circulation 2007;115(20):e478–e534. Crossref, MedlineGoogle Scholar
  • 21 Yokogami K, Nakano S, Ohta H, Goya T, Wakisaka S. Prediction of hemorrhagic complications after thrombolytic therapy for middle cerebral artery occlusion: value of pre- and post-therapeutic computed tomographic findings and angiographic occlusive site. Neurosurgery 1996;39(6):1102–1107. Crossref, MedlineGoogle Scholar
  • 22 Graser A, Johnson TR, Chandarana H, Macari M. Dual energy CT: preliminary observations and potential clinical applications in the abdomen. Eur Radiol 2009;19(1):13–23. Crossref, MedlineGoogle Scholar
  • 23 Graser A, Johnson TR, Hecht EM, et al.. Dual-energy CT in patients suspected of having renal masses: can virtual nonenhanced images replace true nonenhanced images? Radiology 2009;252(2):433–440. LinkGoogle Scholar
  • 24 Ruzsics B, Lee H, Zwerner PL, Gebregziabher M, Costello P, Schoepf UJ. Dual-energy CT of the heart for diagnosing coronary artery stenosis and myocardial ischemia-initial experience. Eur Radiol 2008;18(11):2414–2424. Crossref, MedlineGoogle Scholar
  • 25 Thieme SF, Johnson TR, Lee C, et al.. Dual-energy CT for the assessment of contrast material distribution in the pulmonary parenchyma. AJR Am J Roentgenol 2009;193(1):144–149. Crossref, MedlineGoogle Scholar
  • 26 Ferda J, Novák M, Mírka H, et al.. The assessment of intracranial bleeding with virtual unenhanced imaging by means of dual-energy CT angiography. Eur Radiol 2009;19(10):2518–2522. Crossref, MedlineGoogle Scholar
  • 27 Chandarana H, Godoy MC, Vlahos I, et al.. Abdominal aorta: evaluation with dual-source dual-energy multidetector CT after endovascular repair of aneurysms—initial observations. Radiology 2008;249(2):692–700. LinkGoogle Scholar
  • 28 Stolzmann P, Scheffel H, Rentsch K, et al.. Dual-energy computed tomography for the differentiation of uric acid stones: ex vivo performance evaluation. Urol Res 2008;36(3–4):133–138. Crossref, MedlineGoogle Scholar
  • 29 Lell MM, Hinkmann F, Nkenke E, et al.. Dual energy CTA of the supraaortic arteries: technical improvements with a novel dual source CT system. Eur J Radiol doi:10.1016/j.ejrad.2009.09.022. Published online October 8, 2009.. Google Scholar
  • 30 Choi HK, Al-Arfaj AM, Eftekhari A, et al.. Dual energy computed tomography in tophaceous gout. Ann Rheum Dis 2009;68(10):1609–1612. Crossref, MedlineGoogle Scholar

Article History

Received September 30, 2009; revision requested November 4; revision received December 11; accepted February 3, 2010; final version accepted April 27.
Published online: Oct 2010
Published in print: Oct 2010