Introduction: The purpose of this prospective study was to compare a novel dual-energy CTA (DECTA) method for postoperative assessment of coiled brain aneurysms to detect aneurysm recanalization and patency of adjacent blood vessels, with catheter-based digital subtraction angiography (DSA).

Methods: Patients who underwent endovascular cerebral aneurysm coiling were prospectively evaluated postoperatively by both DECTA and conventional DSA. CTA was performed using a novel dual-energy method with single source and fast kilovoltage switching. DSA was performed using biplanar cerebral angiography. An experienced neuroradiologist and neurosurgeon both blinded to the original radiological results reviewed the images.

Results: Fifty-four patients (38 female and 16 male, average age 47.6+9) with 55-coiled aneurysms were enrolled in our study between July 2014 and June 2015. Twenty-nine patients suffered a subarachnoid hemorrhage (SAH), and 26 patients had an incidentally found cerebral aneurysm. All patients had at least one DSA and DECTA performed at most one week apart from each other. DECTA showed a 100% sensitivity and specificity in detection of complete aneurysm occlusion and 80% sensitivity and specificity for detection of residual necks and domes. DECTA successfully detected all vascular diameter changes as comparable as DSA with minimal interfering artifact.

Conclusions: Dual energy CTA is a promising non-invasive alternative to conventional catheter-based angiography for identification of aneurysm recurrence and assessment of adjacent arteries following endovascular coiling. It allows for far more rapid image acquisition than DSA, non-invasive and is widely available at clinical centers.

Patient Care: By preventing unnecessary invasive follow up images, we can decrease the risk of stroke, radiation and save money and human efforts.

Learning Objectives: -Understanding the role of Dual energy CTA in evaluation of coiled aneurysm. -How we can we prevent unnecessary invasive follow up images like cerebral catheter angiography with non-invasive images after coiling an aneurysm

References: 1. Raymond J, Guilbert F, Weill A, et al. Long-term angiographic recurrences after selective endovascular treatment of aneurysms with detachable coils. Stroke. 2003;34(6):1398-1403. 2. Gallas S, Januel AC, Pasco A, et al. Long-term follow-up of 1036 cerebral aneurysms treated by bare coils: a multicentric cohort treated between 1998 and 2003. AJNR Am J Neuroradiol. 2009;30(10):1986-1992. 3. Nguyen TN, Hoh BL, Amin-Hanjani S, Pryor JC, Ogilvy CS. Comparison of ruptured vs unruptured aneurysms in recanalization after coil embolization. Surg Neurol. 2007;68(1):19-23. 4. Ogilvy CS, Chua MH, Fusco MR, Reddy AS, Thomas AJ. Stratification of recanalization for patients with endovascular treatment of intracranial aneurysms. Neurosurgery. 2015;76(4):390-395; discussion 395. 5. U-King-Im JM, Koo B, Trivedi RA, et al. Current diagnostic approaches to subarachnoid haemorrhage. Eur Radiol. 2005;15(6):1135-1147. 6. White PM, Wardlaw JM, Easton V. Can noninvasive imaging accurately depict intracranial aneurysms? A systematic review. Radiology. 2000;217(2):361-370. 7. Fifi JT, Meyers PM, Lavine SD, et al. Complications of modern diagnostic cerebral angiography in an academic medical center. J Vasc Interv Radiol. 2009;20(4):442-447. 8. Kaufmann TJ, Huston J, Mandrekar JN, Schleck CD, Thielen KR, Kallmes DF. Complications of diagnostic cerebral angiography: evaluation of 19,826 consecutive patients. Radiology. 2007;243(3):812-819. 9. Heiserman JE, Dean BL, Hodak JA, et al. Neurologic complications of cerebral angiography. AJNR Am J Neuroradiol. 1994;15(8):1401-1407; discussion 1408-1411. 10. Dion JE, Gates PC, Fox AJ, Barnett HJ, Blom RJ. Clinical events following neuroangiography: a prospective study. Stroke. 1987;18(6):997-1004. 11. Earnest F, Forbes G, Sandok BA, et al. Complications of cerebral angiography: prospective assessment of risk. AJR Am J Roentgenol. 1984;142(2):247-253. 12. Waugh JR, Sacharias N. Arteriographic complications in the DSA era. Radiology. 1992;182(1):243-246. 13. Hacein-Bey L, Provenzale JM. Current imaging assessment and treatment of intracranial aneurysms. AJR Am J Roentgenol. 2011;196(1):32-44. 14. Ogawa T, Okudera T, Noguchi K, et al. Cerebral aneurysms: evaluation with three-dimensional CT angiography. AJNR Am J Neuroradiol. 1996;17(3):447-454. 15. Korogi Y, Takahashi M, Katada K, et al. Intracranial aneurysms: detection with three-dimensional CT angiography with volume rendering--comparison with conventional angiographic and surgical findings. Radiology. 1999;211(2):497-506. 16. Villablanca JP, Martin N, Jahan R, et al. Volume-rendered helical computerized tomography angiography in the detection and characterization of intracranial aneurysms. J Neurosurg. 2000;93(2):254-264. 17. Matsumoto M, Sato M, Nakano M, et al. Three-dimensional computerized tomography angiography-guided surgery of acutely ruptured cerebral aneurysms. J Neurosurg. 2001;94(5):718-727. 18. Shinohara Y, Sakamoto M, Iwata N, et al. Usefulness of monochromatic imaging with metal artifact reduction software for computed tomography angiography after intracranial aneurysm coil embolization. Acta Radiol. 2014;55(8):1015-1023. 19. Masaryk AM, Frayne R, Unal O, Rappe AH, Strother CM. Utility of CT angiography and MR angiography for the follow-up of experimental aneurysms treated with stents or Guglielmi detachable coils. AJNR Am J Neuroradiol. 2000;21(8):1523-1531. 20. Wallace RC, Karis JP, Partovi S, Fiorella D. Noninvasive imaging of treated cerebral aneurysms, part I: MR angiographic follow-up of coiled aneurysms. AJNR Am J Neuroradiol. 2007;28(6):1001-1008. 21. Spilberg G, Carniato SL, King RM, et al. Temporal evolution of susceptibility artifacts from coiled aneurysms on MR angiography: an in vivo canine study. AJNR Am J Neuroradiol. 2012;33(4):655-660. 22. Heiserman JE. MR angiography for the diagnosis of vasospasm after subarachnoid hemorrhage. Is it accurate? Is it safe? AJNR Am J Neuroradiol. 2000;21(9):1571-1572. 23. Fahrendorf DM, Goericke SL, Oezkan N, et al. The value of dual-energy CTA for control of surgically clipped aneurysms. Eur Radiol. 2011;21(10):2193-2201. 24. Dolati P, Eichberg D, Wong JH, Goyal M. The Utility of Dual-Energy Computed Tomographic Angiography for the Evaluation of Brain Aneurysms after Surgical Clipping: A Prospective Study. World Neurosurg. 2015. 25. Roy D, Milot G, Raymond J. Endovascular treatment of unruptured aneurysms. Stroke. 2001;32(9):1998-2004. 26. Gallas S, Pasco A, Cottier JP, et al. A multicenter study of 705 ruptured intracranial aneurysms treated with Guglielmi detachable coils. AJNR Am J Neuroradiol. 2005;26(7):1723-1731. 27. Molyneux AJ, Kerr RS, Birks J, et al. Risk of recurrent subarachnoid haemorrhage, death, or dependence and standardised mortality ratios after clipping or coiling of an intracranial aneurysm in the International Subarachnoid Aneurysm Trial (ISAT): long-term follow-up. Lancet Neurol. 2009;8(5):427-433. 28. Kurre W, Berkefeld J. Materials and techniques for coiling of cerebral aneurysms: how much scientific evidence do we have? Neuroradiology. 2008;50(11):909-927. 29. Morhard D, Fink C, Graser A, Reiser MF, Becker C, Johnson TR. Cervical and cranial computed tomographic angiography with automated bone removal: dual energy computed tomography versus standard computed tomography. Invest Radiol. 2009;44(5):293-297. 30. Pessis E, Campagna R, Sverzut JM, et al. Virtual monochromatic spectral imaging with fast kilovoltage switching: reduction of metal artifacts at CT. Radiographics. 2013;33(2):573-583. 31. Silva AC, Morse BG, Hara AK, Paden RG, Hongo N, Pavlicek W. Dual-energy (spectral) CT: applications in abdominal imaging. Radiographics. 2011;31(4):1031-1046; discussion 1047-1050. 32. Barrett JF, Keat N. Artifacts in CT: recognition and avoidance. Radiographics. 2004;24(6):1679-1691. 33. Li Q, Lv F, Li Y, Li K, Luo T, Xie P. Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography. Eur Radiol. 2009;19(9):2261-2267. 34. Brown JH, Lustrin ES, Lev MH, Ogilvy CS, Taveras JM. Reduction of aneurysm clip artifacts on CT angiograms: a technical note. AJNR Am J Neuroradiol. 1999;20(4):694-696. 35. Mamourian AC, Erkmen K, Pluta DJ. Nonhelical acquisition CT angiogram after aneurysmal clipping: in vitro testing shows diminished artifact. AJNR Am J Neuroradiol. 2008;29(4):660-662. 36. Pechlivanis I, König M, Engelhardt M, et al. Evaluation of clip artefacts in three-dimensional computed tomography. Cent Eur Neurosurg. 2009;70(1):9-14. 37. Golitz P, Struffert T, Ganslandt O, et al. Optimized angiographic computed tomography with intravenous contrast injection: an alternative to conventional angiography in the follow-up of clipped aneurysms? Journal of neurosurgery. 2012;117(1):29-36. 38. Lee YH, Park KK, Song HT, Kim S, Suh JS. Metal artefact reduction in gemstone spectral imaging dual-energy CT with and without metal artefact reduction software. Eur Radiol. 2012;22(6):1331-1340. 39. Bamberg F, Dierks A, Nikolaou K, Reiser MF, Becker CR, Johnson TR. Metal artifact reduction by dual energy computed tomography using monoenergetic extrapolation. Eur Radiol. 2011;21(7):1424-1429. 40. Matsumoto K, Jinzaki M, Tanami Y, Ueno A, Yamada M, Kuribayashi S. Virtual monochromatic spectral imaging with fast kilovoltage switching: improved image quality as compared with that obtained with conventional 120-kVp CT. Radiology. 2011;259(1):257-262. 41. Kaza RK, Platt JF, Cohan RH, Caoili EM, Al-Hawary MM, Wasnik A. Dual-energy CT with single- and dual-source scanners: current applications in evaluating the genitourinary tract. Radiographics. 2012;32(2):353-369. 42. Tawfik AM, Kerl JM, Razek AA, et al. Image quality and radiation dose of dual-energy CT of the head and neck compared with a standard 120-kVp acquisition. AJNR Am J Neuroradiol. 2011;32(11):1994-1999. 43. Liu PT, Pavlicek WP, Peter MB, Spangehl MJ, Roberts CC, Paden RG. Metal artifact reduction image reconstruction algorithm for CT of implanted metal orthopedic devices: a work in progress. Skeletal Radiol. 2009;38(8):797-802. 44. Yeh BM, Shepherd JA, Wang ZJ, Teh HS, Hartman RP, Prevrhal S. Dual-energy and low-kVp CT in the abdomen. AJR Am J Roentgenol. 2009;193(1):47-54. 45. Thomas C, Patschan O, Ketelsen D, et al. Dual-energy CT for the characterization of urinary calculi: In vitro and in vivo evaluation of a low-dose scanning protocol. Eur Radiol. 2009;19(6):1553-1559.