Spin lock and magnetization transfer MR imaging of local liver lesions.
The present study was designed to evaluate tissue contrast characteristics obtained with the spin-lock (SL) technique by comparing the results with those generated with a magnetization transfer(MT)-weighted gradient echo [GRE, echo-time (TE)=40 ms] sequence. Twenty-eight patients with hepatic hemangiomas (n=14), or metastatic liver lesions (n=14) were imaged at 0.1 T by using identical imaging parameters. Gradient echo, single-slice off-resonance MT, and multiple-slice SL sequences were obtained. SL and MT-effects were measured from the focal liver lesions and from normal liver parenchyma. In addition, tissue contrast values for the liver lesions were determined. Statistically significant difference between the SL-effects of the hemangiomas and metastases, and also between the MT-effects of the lesions was observed (p < 0.02). Tissue contrast values for the lesions proved to be quite similar between the SL and MT techniques. Our results indicate that at 0.1 T multiple-slice SL imaging provides MT based tissue contrast characteristics in tissues rich in protein with good imaging efficiency and wide anatomical coverage, and with reduced motion and susceptibility artifacts.
Halavaara
J T
JT
Department of Radiology, Helsinki University Central Hospital, Finland. jhalavaa@helsinki.fi
Sepponen
R E
RE
Lamminen
A E
AE
Vehmas
T
T
Bondestam
S
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000473:pathology; D003110:Colonic Neoplasms / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006391:Hemangioma / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology* / Q000556:secondary; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results