Journal of magnetic resonance imaging : JMRI
-
J Magn Reson Imaging · May 2007
ReviewImaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI.
"When one admits that nothing is certain one must, I think, also admit that some things are much more nearly certain than others." Bertrand Russell (1872-1970) Computed tomography (CT) is one of the largest contributors to man-made radiation doses in medical populations. CT currently accounts for over 60 million examinations in the United States, and its use continues to grow rapidly. The principal concern regarding radiation exposure is that the subject may develop malignancies. ⋯ The FDA estimates that a CT examination with an effective dose of 10 mSv may be associated with an increased chance of developing fatal cancer for approximately one patient in 2000, whereas the BEIR VII lifetime risk model predicts that with the same low-dose radiation, approximately one individual in 1000 will develop cancer. There are uncertainties in the current radiation risk estimates, especially at the lower dose levels encountered in CT. To address what should be done to ensure patient safety, in this review we discuss the "as low as reasonably achievable" (ALARA) principle, and the use of MRI as an alternative to CT.
-
J Magn Reson Imaging · May 2007
Comparative StudyMRCP imaging at 3.0 T vs. 1.5 T: preliminary experience in healthy volunteers.
To evaluate the impact of magnetic resonance cholangiopancreatography (MRCP) imaging at 1.5T and 3.0T on image quality. ⋯ Our experience suggests that MRCP imaging at 3.0T has the potential to provide excellent images. High-resolution heavily T2W imaging with a small voxel size (1.3 x 1.3 x 1.4 mm) at 3.0T can provide diagnostic images and allow evaluation of small pathologies of the bile and pancreatic ducts, which 1.5T MRI cannot sufficiently visualize.
-
J Magn Reson Imaging · May 2007
Multiple regression method for pulmonary apparent diffusion coefficient measurement by hyperpolarized 3He MRI.
To develop and validate a new multiple regression technique for the separation of flip angle effect in pulmonary apparent diffusion coefficient (ADC) measurement. ⋯ With the introduction of a nonlinear progression in the diffusion-sensitization gradients, the multiple regression technique is capable of separating the flip angle effect in ADC measurement. In addition, this technique can perform a rigorous measurement uncertainty analysis and provide the optimal scan parameters that yield best noise performance.
-
J Magn Reson Imaging · May 2007
FAIR-TrueFISP imaging of cerebral perfusion in areas of high magnetic susceptibility differences at 1.5 and 3 Tesla.
To estimate cerebral blood perfusion in areas of strong magnetic susceptibility changes with high spatial and temporal resolution using a flow-sensitive alternating inversion recovery (FAIR) arterial spin labeling (ASL) method. ⋯ FAIR-TrueFISP allows for assessment of cerebral perfusion in areas of critically high susceptibility changes with conventional ASL methods.
-
J Magn Reson Imaging · Apr 2007
Superparamagnetic iron oxide (SPIO)-enhanced liver MRI with ferucarbotran: efficacy for characterization of focal liver lesions.
To evaluate the efficacy of ferucarbotran in T2-weighted (T2W) fast spin-echo (FSE) and T2*W gradient-echo (GRE) sequences for characterizing focal liver lesions. ⋯ The PSIL can be an accurate tool for characterizing benign and malignant lesions. The addition of a CE-T2*W GRE sequence is helpful for the detection and characterization of malignant lesions.