Optimized angiographic computed tomography with intravenous contrast injection: an alternative to conventional angiography in the follow-up of clipped aneurysms?

OBJECT The purpose of this study was to evaluate the diagnostic accuracy of an optimized angiographic CT (ACT) program with intravenous contrast agent injection (ivACT) in the assessment of potential aneurysm remnants after neurosurgical clipping compared with conventional digital subtraction angiography (DSA). METHODS The authors report on 14 patients with 19 surgically clipped cerebral aneurysms who were scheduled to undergo angiographic follow-up. For each patient, the authors performed ivACT with dual rotational acquisition and conventional angiography including a 3D rotational run. The ivACT and 3D DSA data were reconstructed with different imaging modes, including a newly implemented subtraction mode with motion correction. Thereafter, the data sets were merged by the dual-volume technique, and freely rotatable 3D images were obtained for further analysis. Observed aneurysm remnants were electronically measured and classified for each modality by 2 experienced neuroradiologists. RESULTS Digital subtraction angiography and ivACT both provided high-quality images without motion artifacts. Artifact disturbances from the aneurysm clips led to a compromised, but still sufficient, image quality in 1 case. The ivACT assessed all aneurysm remnants as true-positive up to a minimal size of 2.6×2.4 mm in accordance with the DSA findings. There was a tendency for ivACT to overestimate the size of the aneurysm remnants. All cases without aneurysm remnants on DSA were scored correctly as true-negative by ivACT. CONCLUSIONS By using an optimized image acquisition protocol as well as enhanced postprocessing algorithms, the noninvasive ivACT seems to achieve results comparable to those of conventional angiography in the follow-up of clipped cerebral aneurysms. The authors have shown that ivACT can provide reliable diagnostic information about potential aneurysm remnants after neurosurgical clipping with high sensitivity and specificity, sufficient for clinical decision making, at least for aneurysms in the anterior circulation located distal to the internal carotid artery. These preliminary results may be a promising step to replace conventional angiography by a noninvasive imaging technique in selected cases after aneurysm clipping.

[1]  M. Scholz,et al.  Computed tomographic angiography in the evaluation of clip placement for intracranial aneurysm , 2008, Acta Neurochirurgica.

[2]  W A Kalender,et al.  Neuroradiologic Applications with Routine C-arm Flat Panel Detector CT: Evaluation of Patient Dose Measurements , 2008, American Journal of Neuroradiology.

[3]  J M Wardlaw,et al.  Can noninvasive imaging accurately depict intracranial aneurysms? A systematic review. , 2000, Radiology.

[4]  W. S. Fisher,et al.  Angiography after aneurysm surgery: indications for "selective" angiography. , 1998, Surgical neurology.

[5]  M. Tymianski,et al.  Postoperative Assessment of Clipped Aneurysms With 64‐Slice Computerized Tomography Angiography , 2010, Neurosurgery.

[6]  M. Lawton,et al.  Late angiographic follow-up review of surgically treated aneurysms. , 1999, Journal of neurosurgery.

[7]  The value of dual-energy CTA for control of surgically clipped aneurysms , 2011, European Radiology.

[8]  J. Gillard,et al.  Current diagnostic approaches to subarachnoid haemorrhage , 2005, European Radiology.

[9]  W A Kalender,et al.  Flat Detector CT in the Evaluation of Brain Parenchyma, Intracranial Vasculature, and Cerebral Blood Volume: A Pilot Study in Patients with Acute Symptoms of Cerebral Ischemia , 2010, American Journal of Neuroradiology.

[10]  H. Kinouchi,et al.  Postoperative three-dimensional CT angiography after cerebral aneurysm clipping with titanium clips: detection with single detector CT. Comparison with intra-arterial digital subtraction angiography. , 2006, Clinical radiology.

[11]  M. Sindou,et al.  [Postoperative arteriography in surgery for intracranial aneurysm. Prospective study in a consecutive series of 267 operated aneurysms]. , 1997, Neuro-Chirurgie.

[12]  A. Fox,et al.  Regrowth of aneurysm sacs from residual neck following aneurysm clipping. , 1989, Journal of neurosurgery.

[13]  C. Lindquist,et al.  Natural history of postoperative aneurysm rests. , 1987, Journal of neurosurgery.

[14]  J. P. Elliott,et al.  Risks and benefits of diagnostic angiography after aneurysm surgery: a retrospective analysis of 597 studies. , 1998, Neurosurgery.

[15]  Sukru Mehmet Erturk,et al.  Comparison of multislice computed tomography angiography and digital subtraction angiography in the detection of residual or recurrent aneurysm after surgical clipping with titanium clips , 2009, Acta Neurochirurgica.

[16]  Fajin Lv,et al.  Subtraction CT angiography for evaluation of intracranial aneurysms: comparison with conventional CT angiography , 2009, European Radiology.

[17]  P. Meyers,et al.  Complications of modern diagnostic cerebral angiography in an academic medical center. , 2009, Journal of vascular and interventional radiology : JVIR.

[18]  J. Ausman,et al.  What percentage of surgically clipped intracranial aneurysms have residual necks? , 2000, Neurosurgery.

[19]  M. Sindou,et al.  Aneurysmal Remnants After Microsurgical Clipping: Classification and Results from a Prospective Angiographic Study (in a Consecutive Series of 305 Operated Intracranial Aneurysms) , 1998, Acta Neurochirurgica.

[20]  V. Rohde,et al.  Feasibility of Flat Panel Angiographic CT after Intravenous Contrast Agent Application in the Postoperative Evaluation of Patients with Clipped Aneurysms , 2011, American Journal of Neuroradiology.

[21]  G. Critchley,et al.  Angiography postclipping and coiling of cerebral aneurysms , 2005, British journal of neurosurgery.

[22]  Marc Saake,et al.  Optimized intravenous Flat Detector CT for non-invasive visualization of intracranial stents: first results , 2011, European Radiology.

[23]  R. Macdonald,et al.  Role of angiography following aneurysm surgery. , 1993, Journal of neurosurgery.

[24]  H. Steiger,et al.  Postoperative spiral computed tomography and magnetic resonance angiography after aneurysm clipping with titanium clips. , 1997, Neurosurgery.

[25]  K. Deng,et al.  Clinical evaluation of dual-energy bone removal in CT angiography of the head and neck: comparison with conventional bone-subtraction CT angiography. , 2009, Clinical radiology.

[26]  L. Regli,et al.  Comparison of multislice computerized tomography angiography and digital subtraction angiography in the postoperative evaluation of patients with clipped aneurysms. , 2006, Journal of neurosurgery.

[27]  T. Struffert,et al.  Flat-detector computed tomography with intravenous contrast material application in experimental aneurysms: Comparison with multislice CT and conventional angiography , 2010, Acta radiologica.

[28]  H. Mori,et al.  Limitations of three-dimensional reconstructed computerized tomography angiography after clip placement for intracranial aneurysms. , 2005, Journal of neurosurgery.

[29]  Evaluation of Postoperative Status after Clipping Surgery in Patients with Cerebral Aneurysm on 3‐Dimensional‐CT Angiography with Elimination of Clips , 2011, Journal of neuroimaging : official journal of the American Society of Neuroimaging.