Time-resolved contrast-enhanced pulmonary MR angiography using sensitivity encoding (SENSE).
OBJECTIVE
To evaluate the relationship between gadolinium concentration and signal-to-noise ratio (SNR) on sensitivity encoding (SENSE) images, and determine the appropriate bolus injection protocol for visualizing pulmonary circulation.


METHODS
Eighteen different gadolinium concentration phantoms (0, 0.01, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.5, 2.0, 5.0, 10.0, 20.0, 30.0, 50.0, and 100.0 mmol/L) were analyzed to determine the relationship between gadolinium concentration and SNR on SENSE images in a phantom study. In an in vivo study, 3 mL (protocol A) or 6 mL (protocol B) of Gd-DTPA BMA at 3 mL/second, and 5 mL of Gd-DTPA BMA at 5 mL/second (protocol C) were administered to eight normal volunteers for contrast-enhanced (CE) pulmonary MR angiography (MRA) with SENSE. The peak SNRs of pulmonary parenchyma and the difference in SNR between pulmonary artery (PA) and pulmonary vein (PV) at peak SNR in the PA were statistically evaluated.


RESULTS
For each flip angle at each gadolinium concentration, the SNRs and contrast-to-noise ratios (CNRs) of the SENSE images were significantly lower than those acquired with a nonparallel imaging technique (P < 0.05). The peak SNR of the pulmonary parenchyma, and differences in SNR between the PA and PV at the peak SNR of the PA obtained with a 5-mL/second bolus injection protocol were found to be significantly higher than those obtained with other protocols (P < 0.05).


CONCLUSIONS
3D-CE-MRA using SENSE demonstrated linearity between gadolinium concentration and SNR, and resulted in MRA with high spatial and temporal resolution with the aid of a sharp bolus injection protocol.
Ohno
Yoshiharu
Y
Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. yoshiharuohno@aol.com
Kawamitsu
Hideaki
H
Higashino
Takanori
T
Takenaka
Daisuke
D
Watanabe
Hirokazu
H
van Cauteren
Marc
M
Fujii
Masahiko
M
Hatabu
Hiroto
H
Sugimura
Kazuro
K
D000328:Adult; D000704:Analysis of Variance; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D005682:Gadolinium / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography; D008297:Male; D019047:Phantoms, Imaging; D011651:Pulmonary Artery / Q000033:anatomy & histology; D011652:Pulmonary Circulation / Q000502:physiology*; D011667:Pulmonary Veins / Q000033:anatomy & histology; D012016:Reference Values; D013997:Time Factors
D003287:Contrast Media; D005682:Gadolinium