BlueCross BlueShield of Tennessee Medical Policy Manual

Computed Tomography (CT) Perfusion Imaging

DESCRIPTION

Computed tomography (CT) perfusion imaging provides an assessment of cerebral blood flow that may assist in the identification of ischemic regions of the brain. This technology is proposed as a method to aid treatment decisions in individuals being evaluated for acute ischemic stroke, subarachnoid hemorrhage, cerebral vasospasm, brain tumors, and head trauma.

CT perfusion imaging performs by capturing images as an iodinated contrast agent bolus passes through the cerebral circulation and accumulates in the cerebral tissues. The quantitative perfusion parameters are calculated from density changes for each pixel over time with commercially available deconvolution-based software. Similar information can be provided by CT and MRI. However, CT has a short protocol time (5-6 minutes) and, because perfusion imaging can be performed with any modern CT equipment, is more widely available in the emergency department setting.

The approved therapy for stroke treatment, intravenous tissue plasminogen activator (tPA), requires only a non‒contrast CT scan to exclude the presence of hemorrhage (a contraindication to the use of the drug). Current guidelines are to administer tPA within the first 3 hours after an ischemic event, preceded by a CT scan. However, some individuals do not present within the 3-hour window. Thus, more sophisticated imaging may be needed to select the proper use of intra-arterial thrombolysis or mechanical thrombectomy.

POLICY

See also:  Mechanical Embolectomy

MEDICAL APPROPRIATENESS

IMPORTANT REMINDERS

ADDITIONAL INFORMATION

CT perfusion is one of several approaches that have been used in acute stroke to better define ischemic tissue that is viable and therefore may benefit from mechanical endovascular intervention. The evidence is sufficient to determine qualitatively that the technology results in a meaningful improvement in the net health outcome.

SOURCES

American College of Radiology. (2014). ACR-ASNR-SPR Practice parameter for the performance of computed tomography (CT) perfusion in neuroradiologic imaging. Retrieved January 14, 2015 from http://www.acr.org/~/media/ACR/Documents/PGTS/guidelines/CT_Perfusion.pdf.

American Heart Association. American Stroke Association. (2012). Guidelines for the management of aneurysmal subarachnoid hemorrhage: A guideline for healthcare professionals from the American Heart Association/American Stroke Association. Retrieved April 26, 2013 from http://stroke.ahajournals.org/content/43/6/1711.

American Heart Association. American Stroke Association. (2013). Guidelines for the early management of patients with acute ischemic stroke: A guideline for healthcare professionals from the American Heart Association/American Stroke Association. Retrieved April 26, 2013 from http://stroke.ahajournals.orgt/content/44/3/870.

American Heart Association. American Stroke Association. (2014). Guidelines the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals Retrieved November 9, 2015 from: http://stroke.ahajournals.org.

Bivard,A., Levi, C., Krishnamurthy, V., McElduff, P., Miteff, F., Spratt, N., et. al., (2015, March) Perfusion computed tomography to assist decision making for stroke thrombolysis. Brain, Journal of Neurology. 2015: 138; 1919–1931. (Level 2 evidence)

BlueCross BlueShield Association. Medical Policy Reference Manual. (10:2015). Computed tomography (CT) perfusion imaging (6.01.49). Retrieved November 9, 2015 from BlueWeb. (34 articles and/or guidelines reviewed)

California Technology Assessment Forum (2012, March) Use of thrombectomy device for the emergent treatment of acute ischemic stroke. Retrieved November 9, 2015 from: http://www.ctaf.org/  (84 articles and/or guidelines reviewed)

Campbell, B., Mitchell, P., Kleinig, T., Dewey, H., Churilov, L., Yassi, N., et. al., (2015, February) Endovascular therapy for ischemic stroke with perfusion-imaging selection. New England Journal of Medicine. 2015;372:1009-18 (Level 1 evidence)

Center for Medicare and Medicaid Services. CMS.gov. (2015, October) Palmetto Government Benefits Administrator. Local Coverage Determination (LCD) Non-covered category III cpt codes (L34555). Retrieved November 9, 2015 from: https://www.cms.gov/.

National Institute for Health and Care Excellance (2008, July) Stroke and transient ischaemic attack in over 16s: diagnosis and initial management. Retrieved November 9, 2015 from: http://www.nice.org/uk.

Silva, G. S., Lima, F. O., Camargo, E. C. S., Smith, W. S., Singhal, A. B., Greer, D. M., et al. (2010). Wake-up stroke: Clinical and neuroimaging characteristics. Cerebrovascular Disease, 29, 336-342.

Technology Evaluation Center (2015, January) Endovascular treatments for acute ischemic stroke in adults. Vol. 29. No. 11. Retrieved November 9, 2015 from: http://bluewebportal.bcbs.com/programs/center-clinical-effectiveness/assessments (30 articles and/or guidelines reviewed)

U. S. Food and Drug Administration. (2008, June). Center for Devices and Radiological Health. 510(k) Premarket Notification Database. K081482. Retrieved July 7, 2011 from http://www.accessdata.fda.gov/cdrh_docs/pdf8/K081482.pdf.

U. S. Food and Drug Administration. (2008, June). Center for Devices and Radiological Health. 510(k) Premarket Notification Database. K33832. Retrieved November 9, 2015 from http://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (2008, June). Center for Devices and Radiological Health. 510(k) Premarket Notification Database. K052839 Retrieved November 9, 2015 from http://www.accessdata.fda.gov.

U. S. Food and Drug Administration. (2010, November). Center for Devices and Radiological Health. Medical devices. Safety investigation of CT brain perfusion scans: Update. Retrieved June 28, 2011 from http://www.fda.gov/medicaldevices/safety/alertsandnotices/ucm185898.htm.

ORIGINAL EFFECTIVE DATE:  12/10/2011  

MOST RECENT REVIEW DATE:  2/20/2016

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