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(Circulation. 2006;114:e499-e500.)
© 2006 American Heart Association, Inc.

Images in Cardiovascular Medicine

Angiographic Computed Tomography for Imaging of Underdeployed Intracranial Stent

Goetz Benndorf, MD, PhD; Richard P. Klucznik, MD; Charles M. Strother, MD

From the Methodist Hospital Research Institute (G.B.), Department of Radiology (G.B., R.P.K., C.M.S.), The Methodist Hospital, Houston, Tex.

Correspondence to Goetz Benndorf, MD, PhD, Department of Radiology, The Methodist Hospital, 6565 Fannin, Houston, TX 77030. E-mail gbenndorf{at}tmh.tmc.edu

A 77-year-old woman presented with a transient ischemic attack. Cerebral angiography showed occlusion of the supraclinoid segment of the right internal carotid artery, a persistent trigeminal artery, and an 80% stenosis of the cavernous segment of the internal carotid artery. After deployment of a 3 mm x13 mm, balloon-expandable stent (Bx SONIC, Cordis, Miami Lakes, Fla), a control angiogram demonstrated a residual stenosis, which remained even after repeated balloon inflation. An underlying calcification was assumed. (Figure, A). Although the patient had remained asymptomatic since initial treatment, the angiographic follow-up after 6 months showed a significant in-stent restenosis (Figure, B). Nonsubtracted images could not provide sufficient diagnostic information about the stent itself because of sphenoid osseous structures adjacent and surrounding the cavernous carotid artery (Figure, C and D).

View larger version (112K): [in this window] [in a new window]   A and B, Right internal carotid artery injection, later view immediately after stenting shows a residual stenosis of the cavernous segment (A, arrow). A follow-up angiogram 6 months later shows the development of in-stent restenosis (B, double arrow). Note also the occlusion of the supraclinoid segment (short arrow) and the prominent persistent trigeminal artery supplying the posterior circulation (arrowheads). C and D, Nonsubtracted images lateral and anteroposterior (B) view shows the stent (dashed arrows) insufficiently because of overlying osseous structures in the parasellar region. E and F, Maximum intensity projections in 5-mm sections (angiographic computed tomogram) revealing not only the effective narrowing of the stent but also its cause: Heavily calcified circumferential plaque (white arrowheads). G and H, Plaque consists not only of a hard, calcified portion (arrowhead) but contains also a soft, noncalcified (fibrous, arrow) component as demonstrated in orthogonal projections ("down-the-barrel views").

A non–contrast-enhanced angiographic computed tomogram, using a rotating C-arm with a newly available flat panel detector (Axiom Artis dBA [DynaCT], Siemens Medical Solutions, Erlangen, Germany), was performed by using the following parameters: 20-second rotation, increment of 0.4°, 538 projections, 512x512 matrix). It revealed that the stent was underdeployed as the result of a heavily calcified circumferential plaque (Figure, E and F). Multiplanar reconstructions in orthogonal ("down-the-barrel") views demonstrated not only the different diameters within the stent lumen but also that the plaque consisted of a calcified (hard) and a noncalcified (soft) portion (Figure, G and H). Detection of stent underdeployment or asymmetric deployment, a potential major factor for development of in-stent restenosis, is a diagnostic dilemma in intracranial stenting. In particular, in the petrous, cavernous, and paraclinoid carotid artery as well as in the distal vertebral or proximal basilar artery, where overlying bony structures impair significantly radiographic visualization of small stents, diagnostic information obtained through the use of conventional imaging techniques is currently insufficient.

Because of the high contrast and spatial resolution of modern flat-panel detector systems, angiographic computed tomography provides 3-dimensional images in excellent quality, adding valuable diagnostic information to digital subtraction angiography or digital radiography while the patient is still on the table.^1,2 This promising new technique may play a major role in future diagnostic imaging of the stenting procedure as well as of follow-up studies.

	Disclosures

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None.

	Footnotes

 
The online-only Data Supplement, which contains a movie, can be found at http://circ.ahajournals.org/cgi/content/full/114/12/e499/DC1.

	References

Top Disclosures References

 
1. Benndorf G, Strother CM, Claus B, Naeini R, Morsi H, Kluzcnik R, Mawad M. Angiographic computed tomography (ACT) in cerebrovascular stenting. AJNR Am J Neuroradiol. 2005; 26: 1813–1818.[Abstract/Free Full Text]

2. Benndorf G, Claus B, Strother CM, Chang L, Klucznik RP. Increased cell opening and prolapse of struts of a neuroform stent in curved vasculature: value of angiographic computed tomography: technical case report. Neurosurgery. 2006; 58 (4 suppl 2): ONS–E380.[Medline] [Order article via Infotrieve]

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This Article Extract Full Text (PDF) Data Supplement Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Benndorf, G. Articles by Strother, C. M. Search for Related Content PubMed PubMed Citation Articles by Benndorf, G. Articles by Strother, C. M. Related Collections Restenosis Catheter-based coronary interventions: stents CT and MRI Carotid Stenosis Angiography Computerized tomography and Magnetic Resonance Imaging Risk Factors for Stroke