3D MPRAGE evaluation of lesions in the posterior cranial fossa.
Standard spin-echo images of the posterior cranial fossa are usually impaired by pulsation artifacts. We evaluated a heavily T1 weighted MPRAGE sequence (TR/TE/alpha/TI = 10/4/10-15 degrees/200-350) for detection of intracerebral lesions in the posterior fossa in 11 patients. Overall quality of the MPRAGE images was superior due to the lack of pulsation artifacts, high S/N and excellent gray-white matter contrast. Lesion detection was better in one patient, equal in six and inferior in four patients compared to SE technique. A cerebellar metastasis (8 mm) in one patient was completely blurred from pulsation artifacts on the SE images. Whereas multiple small lesions (< or = 4 mm) with discrete contrast enhancement were missed on the MPRAGE images in three patients. We conclude, that the MPRAGE sequence yields high quality images with isotropic spatial resolution in a reasonable time. But MPRAGE with these parameters can not replace standard SE images in screening the posterior fossa, because of a decreased sensitivity in the detection of small contrast-enhancing lesions.
Wenz
F
F
Department of Radiological Diagnostics and Therapy, German Cancer Research Center (dkfz), Heidelberg.
Hess
T
T
Knopp
M V
MV
Weisser
G
G
Blüml
S
S
Schad
L R
LR
Hawighorst
H
H
van Kaick
G
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003388:Cranial Fossa, Posterior / Q000473:pathology*; D005260:Female; D006801:Humans; D015192:Infratentorial Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies