In an intraindividual comparative study, 5 volunteers (three women, two men; mean age, 38, range, 36–41 years) with no history of neurological
disease underwent 3 Tesla MRI (SIEMENS Magnetom Skyra) brain scan using a 64-channel head/neck array coil and quantitatively compared to a
20-channel head/neck array coil.
Axial T1, T2-weighted sequences (Table 1) were acquired. Quantitative analysis included signal-to-noise (SNR) and contrast-to-noise (CNR) values were calculated based on signal intensity (SI) measurements of selected regions (Figure 2).
T2-weighted images were used for SNR assessment. Regions of interest (ROIs) were placed in selected regions (Caudate Nucleus, CA; Corpus
callosum, CC; Internal Capsule, IC; Putamen, PU; Thalamus, Th; Frontal white matter, FT; Occipital white matter, OC).
T1-weighted FLAIR images were used for CNR assessment at select different regions of gray matter and white matter (GW-WM) structures
(Frontal GM-WM, Head of Caudate GM-WM, Putamen GM-WM, Thalamus GM-WM).
All ROIs (ROI measurements) were carefully placed avoiding area of pulsation. The SNRs were calculated by (mean value in each ROI)/(standard deviation of reference ROI in the extracranial air). In additional, CNRs were calculated as differences between intensity means of gray and white matter/(standard deviation of reference ROI in the extracranial air).
Student’s t test for paired samples was used to compare the SNRs and CNRs obtained from the both array coils. Significance was considered p<0.05.
Qualitative analysis included images from both coils were compared for overall image quality by 2 experienced radiologists using a four-point Likert scale.