Keywords:
CNS, Interventional vascular, Emergency, CT, Thrombolysis, Recanalisation, Complications, Haemorrhage, Embolism / Thrombosis, Ischaemia / Infarction
Authors:
S. VAN HEDENT, N. Grosse Hokamp, R. Beck, R. Kessner, P. R. Ros, D. W. Jordan; Cleveland, OH/US
DOI:
10.1594/ecr2018/C-3280
Aims and objectives
In patients with acute ischemic stroke,
intra-arterial thrombolytic therapy has proven to decrease morbidity and mortality (1).
However,
this increases the risk of intracerebral haemorrhage (ICH) (2-5).
Because of the breakdown of the blood-brain barrier,
contrast extravasation can occur during the procedure,
complicating the detection of ICH due to the overlap in density.
As of writing,
unenhanced conventional CT is performed within 24 hours after treatment for the detection of complications (5,
6).
Follow-up imaging is performed when differentiation of ICH from iodine is difficult.
Early differentiation is important for correct therapeutic adjustment (2).
Materials with a similar attenuation can be difficult to distinguish in conventional CT.
A common clinical illustration of this problem,
is the differentiation of iodine from and haemorrhage because both present as a hyperdensity on conventional unenhanced CT.
Spectral Detector CT (SDCT) (IQon,
Philips Healthcare,
Cleveland,
USA) can expose material-specific differences in attenuation at varying photon energies,
by acquiring low and high energy data using a dual-layer detector.
This technology allows subtraction or quantification of specific materials,
such as iodine,
creating Virtual Non-Contrast (VNC) images (7).
The SDCT utilizes a dual-layer detector for spectral data acquisition,
which absorbs high and low energy photons at the bottom and top layer of the detector,
respectively.
By acquiring spectral data at the level of the detector,
this information is always available and does not need prospective planning or alteration of daily clinical workflow; factors of added importance in neurological emergency imaging.
Previous studies have shown the potential of Dual-Energy CT (DECT) for differentiating iodine from haemorrhage in clinical settings,
by utilizing VNC images (8-13).
As of writing,
no study has been performed using the SDCT for such an application,
nor has the sensitivity of DECT been determined in a phantom system.
In our study,
we investigate the ability of SDCT to differentiate ICH from iodinated contrast in a phantom model.