AJR. American journal of roentgenology
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AJR Am J Roentgenol · Apr 2010
High-resolution double arterial phase hepatic MRI using adaptive 2D centric view ordering: initial clinical experience.
The objective of our study was to evaluate a new 3D fast spoiled gradient-recalled echo (FSPGR) sequence referred to as modified liver acceleration volume acquisition (LAVA) for high-resolution gadolinium-enhanced dual arterial phase liver MRI and to determine the effect of this technique on the timing of the contrast bolus and lesion detection. ⋯ High-resolution dual arterial phase 3D FSPGR MRI improves the timing of the arterial phase of liver enhancement and provides additional information for liver lesion detection.
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AJR Am J Roentgenol · Apr 2010
Estimating effective dose for CT using dose-length product compared with using organ doses: consequences of adopting International Commission on Radiological Protection publication 103 or dual-energy scanning.
The objective of our study was to compare dose-length product (DLP)-based estimates of effective dose with organ dose-based calculations using tissue-weighting factors from publication 103 of the International Commission on Radiological Protection (ICRP) or dual-energy CT protocols. ⋯ These differences in estimates of effective dose suggest the need to reassess DLP to E conversion coefficients when adopting ICRP 103, particularly for scans over the breast. For the evaluated scanner, DLP to E conversion coefficients were energy independent, but ICRP 60-based conversion coefficients underestimated effective dose relative to organ dose-based calculations.
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AJR Am J Roentgenol · Mar 2010
Clinical TrialProspective analysis of the pattern and risk for severe vital sign changes during percutaneous radiofrequency ablation of the liver under opioid analgesia.
The aims of this study were to evaluate the pattern of vital sign changes and to elucidate significant risk factors for severe cardiovascular inhibition caused by percutaneous hepatic radiofrequency ablation (RFA). ⋯ Changes in BP and HR, especially bradycardia, are common during percutaneous RFA of hepatic lesions. Significant risk factors for severe cardiovascular inhibition include contact of the RFA zone with the branches of the central portal vein, old age, and female sex.
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AJR Am J Roentgenol · Mar 2010
Comparative StudyContrast material for abdominal dynamic contrast-enhanced 3D MR angiography with parallel imaging: intraindividual equimolar comparison of a macrocyclic 1.0 M gadolinium chelate and a linear ionic 0.5 M gadolinium chelate.
The purpose of this study was to compare a macrocyclic 1.0 M contrast agent with a linear ionic 0.5 M contrast agent at equimolar dosage in regard to image quality and number of vessel segments visualized at abdominal dynamic contrast-enhanced 3D MR angiography. ⋯ At abdominal contrast-enhanced 3D MR angiography, depiction of small abdominal vessels was significantly better and vessel-to-tissue contrast significantly higher with 1.0 M macrocyclic gadobutrol than with an equimolar dose of 0.5 M linear ionic gadopentetate dimeglumine.
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AJR Am J Roentgenol · Mar 2010
Liver MRI at 3 T using a respiratory-triggered time-efficient 3D T2-weighted technique: impact on artifacts and image quality.
The purpose of this retrospective study was to qualitatively and quantitatively compare image quality of a time-efficient 3D T2-weighted sequence-the sampling perfection with application-optimized contrasts using different flip angle evolutions (SPACE) sequence-with a standard 2D T2-weighted turbo spin-echo (TSE) sequence for liver imaging at 3 T. ⋯ For T2-weighted liver imaging at 3 T, the respiratory-triggered SPACE sequence shows better image quality with near elimination of motion and pulsation artifacts and improved tissue contrast than the breath-hold 2D TSE sequence, but suffers from increased B(1) inhomogeneity artifact and longer scanning time.