Keywords:
Ischaemia / Infarction, Haemodynamics / Flow dynamics, Blood, Imaging sequences, Diagnostic procedure, MR, CT-Angiography, Vascular, Head and neck, Cardiovascular system
Authors:
Y. Stankevich, O. Bogomyakova, L. Shraybman, M. Rezakova, A. Tulupov; Novosibirsk/RU
DOI:
10.1594/ecr2013/C-1751
Methods and Materials
All examinations were performed on a 1.5 T MR-scanner.
Two groups volunteers were examined using routine protocol (T1-WI,
T2-WI,
FLAIR,
3D PC-MRA and DWI) and phase contrast MR-angiography retrospectively cardiac triggered (Quantitative Flow (Q-Flow) technique) [1].
The 60 healthy volunteers at the age 18 - 55 years old were included at control group. The exclusion criteria were any neurological cerebral symptoms,
neoplastic lesions,
or other abnormalities detected on routine MRI exam. The second group was consisted in 15 patients at the age 18 - 36 years old with bilateral ICA S-shape elongation (fig.1),
but without ischemic lesions of brain detected on routine MRI exam.
We observed the values of peak velocity,
mean velocity,
mean flux of vessels at 5 levels of ICA (Fig.2). The scan plane for velocity images was chosen perpendicular to the course of vessel (at sagittal and coronal T1-WI and T2-WI, 3D PC-MRA images),
because flow measurement was possible at the straight portion of artery. Parameters of sequence were as follows: TR=14 ms; TE=8.3 ms; FA=150; slice thickness=5 mm; velocity encoding=90 cm/sec.
In this method each cardiac cycle is divided into 15 phases.
Each phase is associated with vessel diameter and velocity of blood flow.
Blood flow parameters is automatically defined inside the region of interest,
which was marked.
All parameters were calculated by drawing a region of interest manually around the vessel encompassing all pixels on velocity images (Fig.
3).
Statistical analysis was performed by mean value and confidence interval (for p=0.05).
Student’s paired t-test was performed to indicate significant differences between mean values at the patient and control groups.