Interventional 4-D C-Arm CT Perfusion Imaging Using Interleaved Scanning and Partial Reconstruction Interpolation

Abstract

Abstract-Tissue perfusion measurement during catheterguided stroke treatment in the interventional suite is currently not possible. In this work, we present a novel approach that uses a C-arm angiography system capable of CT-like imaging (C-arm CT) for this purpose. With C-arm CT one reconstructed volume can be obtained every 4-6 s which makes it challenging to measure the flow of an injected contrast bolus. We have developed an interleaved scanning (IS) protocol that uses several scan sequences to increase temporal sampling. Using a dedicated 4-D reconstruction approach based on partial reconstruction interpolation (PRI) we can optimally process our data.We evaluated our combined approach (IS-PRI) with simulations and a study in 5 healthy pigs. In our simulations, the cerebral blood flow values (unit: ml/100g/min) were 60 (healthy tissue) and 20 (pathological tissue). For one scan sequence the values were estimated with standard deviations of 14.3 and 2.9, respectively. For two interleaved sequences the standard deviations decreased to 3.6 and 1.5, respectively. We used perfusion CT to validate the in vivo results. With two interleaved sequences we achieved promising correlations ranging from r=0.63 to r=0.94. The results suggest that C-arm CT tissue perfusion imaging is feasible with two interleaved scan sequences.

Dynamic Iterative Reconstruction for Interventional 4-D C-Arm CT Perfusion Imaging

“…We considered the perfusion map slices containing the annotated stroke-affected areas inside a sub-volume of size 256 × 256 × 18. To calculate the PC and RMSE, we applied an automated region of interest (ROI) analysis with vascular pixel elimination (VPE) [3]. Therefore, air and vessel structures were excluded from the perfusion maps according to the brain segmentation.…”

“…In [3], first in vivo results of a PCCT study with healthy pigs were presented. A novel approach for PCCT was used, which combines interleaved scanning with partial volume reconstruction.…”

“…Recently, new approaches have been presented to overcome these problems: an acquisition protocol combining interleaved scanning and partial reconstruction interpolation has been presented and evaluated in [3] and [4]. While providing improved temporal sampling and high computational efficiency, multiple scanning sequences are required, which increases irradiation and contrast agent dose to the patient.…”

Dynamic Angiography and Perfusion Imaging Using Flat Detector CT in the Angiography Suite: A Pilot Study in Patients with Acute Middle Cerebral Artery Occlusions

“…However, recent studies in canines and swine models have now demonstrated the feasibility of dynamic perfusion imaging with the use of a flat detector angiographic system. [10][11][12] The aim of this pilot study was to test the feasibility of this novel application by comparing FD-CTP and FD-CTA with a multimodal MR imaging protocol in patients with acute ischemic stroke. Additionally, the effective patient dose was evaluated.…”

“…The basic reconstruction represents a modified version of the algorithm reported previously, which uses the widely accepted deconvolution approach to calculate the dynamic perfusion parameters. 11,12 The arterial input function was manually selected at the anterior cerebral artery. We reconstructed all parameters maps (eg, TTP, MTT, CBV, and CBF) by using a 5-mm section thickness and spacing.…”