Quantitative analysis of high-resolution, contrast-enhanced, cone-beam CT for the detection of intracranial in-stent hyperplasia

Abstract

BackgroundIntracranial in-stent hyperplasia is a stroke-associated complication that requires routine surveillance.ObjectiveTo compare the results of in vivo experiments to determine the accuracy and precision of in-stent hyperplasia measurements obtained with modified C-arm contrast-enhanced, cone-beam CT (CE-CBCT) imaging with those obtained by ‘gold standard’ histomorphometry. Additionally, to carry out clinical analyses comparing this CE-CBCT protocol with digital subtraction angiography (DSA).MethodsA non-binned CE-CBCT protocol (VasoCT) was used that acquires x-ray images with a small field-of-view and applies a full-scale reconstruction algorithm providing high-resolution three-dimensional (3D) imaging with 100 µm isotropic voxels. In an vivo porcine model, VasoCT cross-sectional area measurements were compared with gold standard vessel histology. VasoCT and DSA were used to calculate in-stent stenosis in 23 imaging studies.ResultsPorcine VasoCT cross-sectional stent, lumen, and in-stent hyperplasia areas strongly correlated with histological measurements (r2=0.97, 0.93, 0.90; slope=1.14, 1.07, and 0.76, respectively; p<0.0001). Clinical VasoCT percentage stenosis correlated well with DSA percentage stenosis (r2=0.84; slope=0.76), and the two techniques were free of consistent bias (Bland–Altman, bias=3.29%; 95% CI −14.75% to 21.33%). An illustrative clinical case demonstrated the advantages of VasoCT, including 3D capability and non-invasive IV contrast administration, for detection of in-stent hyperplasia.ConclusionsC-arm VasoCT is a high-resolution 3D capable imaging technique that has been validated in an animal model for measurement of in-stent tissue growth. Successful clinical implementation of the protocol was performed in a small case series.

The occurrence of neointimal hyperplasia after flow-diverter implantation is associated with cardiovascular risks factors and the stent design

“…The results of our study cannot directly compare with previous reports because here we systematically used VasoCT to evaluate NIH, with this tool having a sensibility closer to histology than DSA to depict NIH 1. We also decided to target and analyze any minimal amount of NIH detectable.…”

Grading of Regional Apposition after Flow-Diverter Treatment (GRAFT): a comparative evaluation of VasoCT and intravascular OCT

“…In addition to conventional digital subtraction angiography and angiographic CT,13 14 high-resolution contrast-enhanced cone-beam CT (VasoCT) has been introduced as a superior three-dimensional angiographic technique to image stent deployment and parent vessel apposition 15 16. VasoCT images are reconstructed from unbinned acquisitions of small field-of-view projection images during a rotational sweep.…”

“…VasoCT images are reconstructed from unbinned acquisitions of small field-of-view projection images during a rotational sweep. The advantage of such detailed reconstructions has already been demonstrated for intracranial visualization of stents,17 microcannulas,18 small arteriovenous malformations,19 and FDs 15 16…”

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results

“…Intracranial CBCTA also correlated well with DSA in assessing in-stent restenosis following intracranial stents or PEDs in clinical studies. 26 The accuracy of intra-arterial CBCTA in assessing the status of PED apposition to the vessel wall has been validated with catheter-based optical coherence tomography endoscopy in in vivo canine models. 27 The use of IVCBCTA as a noninvasive imaging alternative for the assessment of the FIG 2. How the PED-paved vascular segment can still be depicted in the presence of coil-induced metal artifacts is illustrated in the following 2 cases.…”