Non-invasive assessment of vasospasm following aneurysmal SAH using C-arm FDCT parenchymal blood volume measurement in the neuro-interventional suite: Technical feasibility

Abstract

<jats:sec><jats:title>Introduction</jats:title><jats:p> Cerebral vasospasm is the leading cause of morbidity and mortality in patients with aneurysmal subarachnoid haemorrhage (SAH) surviving the initial ictus. Commonly used techniques for vasospasm assessment are digital subtraction angiography and transcranial Doppler sonography. These techniques can reliably identify only the major vessel spasm and fail to estimate its haemodynamic significance. To overcome these issues and to enable comprehensive non-invasive assessment of vasospasm inside the interventional suite, a novel protocol involving measurement of parenchymal blood volume (PBV) using C-arm flat detector computed tomography (FDCT) was implemented. </jats:p></jats:sec><jats:sec><jats:title>Materials and methods</jats:title><jats:p> Patients from the neuro-intensive treatment unit (ITU) with suspected vasospasm following aneurysmal SAH were scanned with a biplane C-arm angiography system using an intravenous contrast injection protocol. The PBV maps were generated using prototype software. Contemporaneous clinically indicated MR scan including the diffusion- and perfusion-weighted sequences was performed. C-arm PBV maps were compared against the MR perfusion maps. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> Distribution of haemodynamic impairment on C-arm PBV maps closely matched the pattern of abnormality on MR perfusion maps. On visual comparison between the two techniques, the extent of abnormality indicated PBV to be both cerebral blood flow and cerebral blood volume weighted. </jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p> C-arm FDCT PBV measurements allow an objective assessment of the severity and localisation of cerebral hypoperfusion resulting from vasospasm. The technique has proved feasible and useful in very sick patients after aneurysmal SAH. The promise shown in this early study indicates that it deserves further evaluation both for post-SAH vasospasm and in other relevant clinical settings. </jats:p></jats:sec>

Feasibility of Flat Panel Detector CT in Perfusion Assessment of Brain Arteriovenous Malformations: Initial Clinical Experience

“…In contrast to FPD-CT studies performed on ischemia 12-15 and on vasospasm 17,18 in our study on bAVMs, perfusion correlated best with CBF. The strongest correlation was found with ASL-CBF.…”

“…[12][13][14][15] However, recently, it has been shown that in vasospasm, FPD-CT perfusion is both CBV-and CBF-weighted. 17,18 Furthermore, parenchymal blood volume maps obtained from CTA source images 23 have been reported to be either CBV-or CBF-weighted, depending on the order of CTA/ CTP data acquisition. 24 In this study, the glomerular bAVMs showed a perinidal hyperperfusion, with a tendency to normalization with increasing distance from the nidus.…”

“…After the C-arm return of the run mask to its starting position, 2D-DSA images at a rate of 2 images per second were acquired for documentation of the contrast passage through the cerebral vasculature. 17,18 The acquisition time was approximately 40 seconds. 14 The reconstructed mask run and fill run were subtracted from each other.…”

“…Flat panel detector CT (FPD-CT) is a novel technique for brain perfusion assessment, providing parenchymal blood volume maps. [11][12][13][14][15][16][17][18] The aim of this study was to investigate the value of FPD-CT in bAVMs, which has not been assessed, yet, to our knowledge. FPD-CT data were compared with DSC-MR imaging and ASL-MR imaging.…”

Flat‐Detector CT to Quantify Response to Intra‐Arterial Spasmolytic Therapy for Cerebral Vasospasm

“…Hence, we look to expand our diagnostic evaluation with CBV imaging. There have also been few studies on how cerebral vasospasm affects cerebral perfusion . Although these reports demonstrated feasibility of measuring how cerebral vasospasm affects perfusion, there are currently no studies investigating the quantitative change in perfusion after injection of a spasmolytic agent using the FDCT scanner.…”