Use of time attenuation curves to determine steady-state characteristics before C-arm CT measurement of cerebral blood volume

作者：Caroff Jildaz^*; Jittapiromsak Pakrit; Ruijters Daniel; Benachour Nidhal; Mihalea Cristian; Rouchaud Aymeric; Neki Hiroaki; Ikka Leon; Moret Jacques; Spelle Laurent

来源：Neuroradiology, 2014, 56(3): 245-249.

DOI：10.1007/s00234-014-1321-7

• Flat detector computed tomography
• Perfusion imaging
• Cerebral blood flow
• Endovascular therapy
• Steady state

Cerebral blood volume (CBV) measurement by flat panel detector CT (FPCT) in the angiography suite seems to be a promising tool for patient management during endovascular therapies. A steady state of contrast agent distribution is mandatory during acquisition for accurate FPCT CBV assessment. To the best of our knowledge, this was the first time that steady-state parameters were studied in clinical practice.
Before the CBV study, test injections were performed and analyzed to determine a customized acquisition delay from injection for each patient. Injection protocol consisted in the administration of 72 mL of contrast agent material at the injection rate of 4.0 mL/s followed by a saline flush bolus at the same injection rate. Peripheral or central venous accesses were used depending on their availability. Twenty-four patients were treated for different types of neurovascular diseases. Maximal attenuation, steady-state length, and steady-state delay from injection were derived from the test injections' time attenuation curves.
With a 15 % threshold from maximum attenuation values, average steady-state duration was less than 10 s. Maximum average steady-state duration with minimal delay variation was obtained with central injection protocols.
With clinically acceptable contrast agent volumes, steady state is a brief condition; thus, fast rotation speed acquisitions are needed. The use of central injections decreases the variability of steady-state's delay from injection. Further studies are needed to optimize and standardize injection protocols to allow a larger diffusion of the FPCT CBV measurement during endovascular treatments.

• 出版日期2014-3