Journal of magnetic resonance imaging : JMRI
-
J Magn Reson Imaging · Jun 2005
Quantitative perfusion measurements using pulsed arterial spin labeling: effects of large region-of-interest analysis.
To study arterial spin labeling (ASL) MRI techniques and to investigate various problematic issues that still hinder the accurate and robust quantitative analysis of ASL data. ⋯ Analysis of ASL data based on a large ROI may suffer from inaccuracies arising from a distribution of transit times, implying that averaging of ASL kinetic data over such regions should therefore be avoided. When possible, a PBP fit should be performed.
-
J Magn Reson Imaging · Jun 2005
Comparative StudyHigh-dose Gd-DTPA vs. Bis-Gd-mesoporphyrin for monitoring laser-induced tissue necrosis.
To compare Bis-Gd-mesoporphyrin (Bis-Gd-MP), a contrast agent with a reported high affinity to necrotic tissue, with high-dose gadopentate dimeglumin (Gd-DTPA) for defining laser-induced muscle and liver necrosis by contrast-enhanced (CE) MRI. ⋯ Bis-Gd-MP and Gd-DTPA are equally well suited for postinterventional lesion assessment in LITT.
-
J Magn Reson Imaging · Jun 2005
Relationship between contrast enhancement on fluid-attenuated inversion recovery MR sequences and signal intensity on T2-weighted MR images: visual evaluation of brain tumors.
To investigate the relationship between the degree of contrast enhancement in fluid-attenuated inversion recovery (FLAIR) sequences and tumor signal intensity on T2-weighted images. ⋯ The signal intensity in FLAIR sequences is largely influenced by both T1 and T2 relaxation time; there is a close relationship between the signal intensity of brain tumors on T2-weighted images and the degree of contrast enhancement on FLAIR sequences. When tumors have higher signal intensity than normal cortex on T2-weighted images, additional postcontrast FLAIR imaging may improve their depiction.