Feasibility of three-dimensional MRI of proximal femur microarchitecture at 3 tesla using 26 receive elements without and with parallel imaging.
OBJECTIVE
High-resolution imaging of deeper anatomy such as the hip is challenging due to low signal-to-noise ratio (SNR), necessitating long scan times. Multi-element coils can increase SNR and reduce scan time through parallel imaging (PI). We assessed the feasibility of using a 26-element receive coil setup to perform 3 Tesla (T) MRI of proximal femur microarchitecture without and with PI.


METHODS
This study had institutional review board approval. We scanned 13 subjects on a 3T scanner using 26 receive-elements and a three-dimensional fast low-angle shot (FLASH) sequence without and with PI (acceleration factors [AF] 2, 3, 4). We assessed SNR, depiction of individual trabeculae, PI performance (1/g-factor), and image quality with PI (1 = nonvisualization to 5 = excellent).


RESULTS
SNR maps demonstrate higher SNR for the 26-element setup compared with a 12-element setup for hip MRI. Without PI, individual proximal femur trabeculae were well-depicted, including microarchitectural deterioration in osteoporotic subjects. With PI, 1/g values for the 26-element/12-element receive-setup were 0.71/0.45, 0.56/0.25, and 0.44/0.08 at AF2, AF3, and AF4, respectively. Image quality was: AF1, excellent (4.8 ± 0.4); AF2, good (4.2 ± 1.0); AF3, average (3.3 ± 1.0); AF4, nonvisualization (1.4 ± 0.9).


CONCLUSIONS
A 26-element receive-setup permits 3T MRI of proximal femur microarchitecture with good image quality up to PI AF2.
Department of Radiology, Center for Musculoskeletal Care, NYU Langone Medical Center, New York, New York, USA.
Gregory
G
Chang
Cem M
CM
Deniz
Stephen
S
Honig
Chamith S
CS
Rajapakse
Kenneth
K
Egol
Ravinder R
RR
Regatte
Ryan
R
Brown
D000368:Aged; D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005260:Female; D005270:Femur Head / Q000473:pathology*; D005271:Femur Head Necrosis / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008280:Magnetics / Q000295:instrumentation; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
MRI; bone microarchitecture; femoral neck; fracture; hip; osteoporosis