Dynamic MR imaging of brain tumors in low field using undersampled projection reconstruction.
A new application of the projection reconstruction method was developed, enabling dynamic T(1)-weighted contrast-enhanced magnetic resonance image (MRI) of brain tumors in a low-field imager. Two undersampled projection reconstruction spin echo sequences were implemented in an open low-field (0.23-T) MR imager, one with 64 and another with 42 projections in [0,pi], repetition time 150 ms, echotime 15 ms, and six slices were used in both sequences. The possibility of using these sequences to image dynamic contrast enhancement of brain tumors was studied in laboratory experiments and in two patient cases, one with fibrotic and the other with meningothelial meningioma. The laboratory experiments showed a nearly linear response in signal intensity to the concentration of gadopentetate dimeglumine in purified water up to 1.25 mM. Increasing concentrations up to 5.0 mM did not significantly affect the signal intensity, though starting from 3.0 mM concentration T(2) shortening decreased intensities slightly. The patient cases showed results consistent with an earlier study performed in a high-field imager. The results show that the studied sequences can be used to follow dynamic contrast enhancement in a low-field imager.
Yrjänä
Sanna K
SK
Department of Neurosurgery, Oulu University Hospital, 90029 Oulu, Finland. sanna.yrjana@oulu.fi
Vaara
Teuvo
T
Karttunen
Ari
A
Katisko
Jani
J
Koivukangas
John
J
D000368:Aged; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D005355:Fibrosis; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D033162:Incidental Findings; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008579:Meningioma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D019786:Gadolinium DTPA