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. It is estimated that a typical perfusion CT deposits a slightly greater radiation dose than a routine unenhanced head CT and covers limited areas of the brain.
POLICY
Computed tomography (CT) perfusion imaging for the diagnosis and management of all neurological indications including, but not limited to, acute cerebral ischemia is considered investigational.
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
ADDITIONAL INFORMATION
In 2009, the U.S. Food and Drug Administration (FDA) issued a communication memo warning that individuals in multiple facilities were receiving excess radiation during perfusion CT imaging that aided in the diagnosis and treatment of strokes. The FDA continued in 2010 to investigate the scope and cause of the excess exposures and the potential health impact to the public and they have initiated recommendations to CT facilities and practitioners to review their perfusion imaging protocols.
In the absence of any well-designed randomized controlled trials addressing computed tomography (CT) perfusion imaging for neurological conditions, no conclusions can be drawn regarding clinical outcomes for these individuals.
SOURCES
American College of Radiology and the American Society of Neuroradiology. (2007). ACR–ASNR practice guideline for the performance of computed tomography (CT) perfusion in neuroradiologic imaging. Retrieved June 28, 2011 from http://www.acr.org/SecondaryMainMenuCategories/quality_safety/guidelines/dx/head-neck/ct_perfusion.aspx.
BlueCross BlueShield Association. Medical Policy Reference Manual. (5:2011). CT (computed tomography) perfusion imaging (6.01.49). Retrieved July 6, 2011 from BlueWeb. (16 articles and/or guidelines reviewed)
Easton, J. D., Saver, J. L., Albers, G. W., Alberts, M. J., Chaturvedi, S., Feldmann, E., et al. (2009). Definition and evaluation of transient ischemic attack: A scientific statement for healthcare professionals from the American Heart Association/American Stroke Association Stroke Council, Council on Cardiovascular Surgery and Anesthesia, Council on Cardiovascular Radiology and Intervention, Council on Cardiovascular Nursing, and the Interdisciplinary Council on Peripheral Vascular Disease. Stroke, 40 (6), 2276-2293.
Ellika, S. K., Jain, R., Patel, S. C., Scarpace, L., Schultz, L. R., Rock, J. P., et al. (2007). Role of perfusion CT in glioma grading and comparison with conventional MR imaging features. American Journal of Neuroradiology, 28 (10), 1981-1987. (Level 4 Evidence - Independent study)
Greenberg, E. D., Gold, R., Reichman, M., John, M., Ivanidze, J., Edwards, A. M., et al. (2010). Diagnostic accuracy of CT angiography and CT perfusion for cerebral vasospasm: A meta-analysis. American Journal of Neuroradiology, 31 (10), 1853-1860.
Hopyan, J., Ciarallo, A., Dowlatshahi, D., Howard, P., John, V., Yeung, R, et al. (2010). Certainty of stroke diagnosis: Incremental benefit with CT perfusion over noncontrast CT and CT angiography. Radiology, 255 (1), 142-153.
Jain, R., Ellika, S. K., Scarpace, L., Schultz, L. R., Rock, J. P., Gutierrez, J., et al. (2008). Quantitative estimation of permeability surface-area product in astroglial brain tumors using perfusion CT and correlation with histopathologic grade. American Journal of Neuroradiology, 29 (4), 694-700. (Level 4 Evidence - Independent study)
Latchaw, R. E., Alberts, M. J., Lev, M. H., Connors, J. J., Harbaugh, R. E., Higashida, R. T., et al. (2009). Recommendations for imaging of acute ischemic stroke: A scientific statement from the American Heart Association. Stroke, 40 (11), 3646-3678.
Ledezma, C. J., & Wintermark, M. (2009). Multi-modal CT in stroke imaging: New concepts. Radiologic Clinics of North America, 47 (1), 109-116.
Lev, M. H. (2007). CT/NIHSS mismatch for detection of salvageable brain in acute stroke triage beyond the 3-hour time window: Overrated or undervalued? Stroke, 38 (7), 2028-2029.
Murphy, B. D., Fox, A. J., Lee, D. H., Sahlas, D. J., Black, S. E., Hogan, M. J., et al. (2008). White matter thresholds for ischemic penumbra and infarct core in patients with acute stroke: CT perfusion study. Radiology, 247 (3), 818-825. (Level 2 Evidence - Industry sponsored)
National Guideline Clearinghouse. (2010, June). Diagnosis and treatment of ischemic stroke. Retrieved June 28, 2011 from http://www.guidelines.gov.
Obach, V., Oleaga, L., Urra, X., Macho, J., Amaro, S., Capurro, S., et al. (2011). Multimodal CT-assisted thrombolysis in patients with acute stroke: A cohort study. Stroke, 42 (4), 1129-1131. (Level 2 Evidence - Independent study)
Scottish Intercollegiate Guidelines Network. (2008, December). Management of patients with stroke or TIA: Assessment, investigation, immediate management and secondary prevention. A national clinical guideline. Retrieved June 28, 2011 from http://www.sign.ac.uk/pdf/sign108.pdf.
U. S. Food and Drug Administration. (2004, February). Center for Devices and Radiological Health. 510(k) Premarket Notification Database. K033677. Retrieved July 7, 2011 from http://www.accessdata.fda.gov/cdrh_docs/pdf3/K033677.pdf.
U. S. Food and Drug Administration. (2006, May). Center for Devices and Radiological Health. 510(k) Premarket Notification Database. K061370. Retrieved July 7, 2011 from http://www.accessdata.fda.gov/cdrh_docs/pdf6/K061370.pdf.
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. (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.
Wintermark, M., Flanders, A. E., Velthuis, B., Meuli, R., van Leeuwen, M., Goldsher, D., et al. (2006). Perfusion-CT assessment of infarct core and penumbra: Receiver operating characteristic curve analysis in 130 patients suspected of acute hemispheric stroke. Stroke, 37 (4), 979-985. (Level 3 Evidence - Industry sponsored)
ORIGINAL EFFECTIVE DATE: 12/10/2011
MOST RECENT REVIEW DATE: 12/10/2011
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