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.
Department of Radiology, Helsinki University Central Hospital, Finland. jhalavaa@helsinki.fi
J T
JT
Halavaara
R E
RE
Sepponen
A E
AE
Lamminen
T
T
Vehmas
S
S
Bondestam
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