Low-Dose Volume-of-Interest C-Arm CT Imaging of Intracranial Stents and Flow Diverters.
OBJECTIVE
Volume-of-interest C-arm CT is a novel technique for imaging of intracranial high-contrast objects. We performed this study to evaluate the potential diagnostic value and radiation dose reduction of this technique for imaging of intracranial stents and flow diverters.


METHODS
Twenty-seven patients were imaged with a VOI C-arm CT scan following treatment with a flow diverter or stent-assisted coiling. The radiation dose-area product was recorded for VOI scans. For comparison, the dose-area product from 30 previously acquired consecutive full-view DynaCTs was used. Thermoluminescence dosimetry by using 35 evenly distributed thermoluminescence dosimeters in an anthropomorphic head phantom was also performed by using both conventional full field and VOI acquisitions. Three observers were presented with VOI images for assessment of the potential diagnostic value.


RESULTS
The dose-area product measurements showed an exposure reduction of 85% compared with the full field acquisitions used for comparison. The thermoluminescence dosimetry evaluations also showed a considerable dose reduction of 79.8% throughout the volume. For most of the evaluated cases, the observers thought that diagnostically useful information was provided by the VOI images (α = .810). Visualization of device details, such as the extent of opening, positioning, wall apposition, and aneurysm coverage, was judged of good diagnostic quality for most cases (88.9%-92.6%).


CONCLUSIONS
In this study, VOI C-arm CT provided high-quality diagnostic images of intracranial stents and flow diverters at a dramatic reduction of radiation exposure. Image content was thought to add useful information. It is a promising method to assess device status during procedures and at follow-up.
From the Department of Neurosurgery (P.Y.), Changhai Hospital, Second Military Medical University, Shanghai, China Departments of Radiology (P.Y., C.S.) 15921196312@163.com pyang75@wisc.edu.
P
http://orcid.org/0000-0002-6154-3602
P
Yang
Neurological Surgery (A.A., D.N., B.A.-K.), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
A
http://orcid.org/0000-0001-7293-496X
A
Ahmed
Siemens Medical Solutions USA (S.S., K.R.), Hoffman Estates, Illinois.
S
http://orcid.org/0000-0002-6989-5215
S
Schafer
Neurological Surgery (A.A., D.N., B.A.-K.), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
D
http://orcid.org/0000-0003-1980-3113
D
Niemann
Neurological Surgery (A.A., D.N., B.A.-K.), University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
B
http://orcid.org/0000-0002-3609-9394
B
Aagaard-Kienitz
Siemens Medical Solutions USA (S.S., K.R.), Hoffman Estates, Illinois.
K
http://orcid.org/0000-0002-5035-7193
K
Royalty
Departments of Radiology (P.Y., C.S.).
C
http://orcid.org/0000-0002-4235-8081
C
Strother
D057510:Endovascular Procedures / Q000295:instrumentation; D005260:Female; D006257:Head; D006801:Humans; D059906:Neuroimaging / Q000379:methods*; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D015607:Stents; D013819:Thermoluminescent Dosimetry / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*