Time-resolved contrast-enhanced magnetic resonance angiography in pediatric patients using sensitivity encoding.
OBJECTIVE
To evaluate the role of time-resolved contrast-enhanced magnetic resonance angiography (CE-MRA) using sensitivity encoding in imaging the thoraco-abdominal vessels in pediatric patients.


METHODS
Thoraco-abdominal vessels of 22 pediatric patients (median age = 5 years) were evaluated with a 3D CE-MRA technique in combination with SENSE following a 0.2 mmol/kg injection of Gd-chelate. The acquisition parameters were as follows: TR/TE = 5/1.1 msec; flip angle = 40 degrees; in-plane phase encoding steps were reduced by a factor of 2 using sensitivity encoding (SENSE); 3D volume acquisition was repeated four to eight times consecutively during free breathing (four to eight dynamics) with a mean temporal resolution of 6.8 seconds/dynamic; and mean acquired voxel size = 1.4 x 1.7 x 3.1 mm (reconstructed as 1.4 x 1.4 x 1.55 mm). Arterial-to-venous signal intensity ratios (AVRs) were computed for each dynamic.


RESULTS
All images were successfully reconstructed and were of diagnostic quality. The AVRs of prepeak, peak, and postpeak arterial volumes were 1.0 +/- 0.5, 6.1 +/- 3.3, and 1.3 +/-0.9, respectively, indicating good arterial-to-venous separation. The signal-to-noise ratio (SNR) of the peak arterial volume was 41 +/- 26.


CONCLUSIONS
Our results suggest that it is feasible to apply SENSE to a conventional 3D CE-MRA technique in a time-resolved fashion for imaging the thoraco-abdominal vessels in pediatric patients during free breathing.
Muthupillai
Raja
R
Philips Medical Systems, Bothell, Washington, USA. raja.Muthupillai@philips.com
Vick
Giles W
GW
Flamm
Scott D
SD
Chung
Taylor
T
D000005:Abdomen / Q000098:blood supply*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003323:Coronary Aneurysm / Q000175:diagnosis; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D018810:Magnetic Resonance Angiography / Q000379:methods*; D011651:Pulmonary Artery / Q000033:anatomy & histology / Q000473:pathology; D012119:Respiration; D013909:Thorax / Q000098:blood supply*; D014682:Vena Cava, Inferior / Q000473:pathology
D003287:Contrast Media