AJR. American journal of roentgenology
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AJR Am J Roentgenol · Apr 2010
Pilot study assessing differentiation of steatosis hepatis, hepatic iron overload, and combined disease using two-point dixon MRI at 3 T: in vitro and in vivo results of a 2D decomposition technique.
The purpose of our study was to evaluate whether two-point Dixon MRI using a 2D decomposition technique facilitates metabolite differentiation between lipids and iron in standardized in vitro liver phantoms with in vivo patient validation and allows semiquantitative in vitro assessment of metabolites associated with steatosis, iron overload, and combined disease. ⋯ MR Dixon imaging facilitates metabolite decomposition of intrahepatic lipids and iron using in vitro phantoms with in vivo patient validation. The proposed decomposition technique identified distinct in-phase/opposed-phase and fat/water ratios for in vitro steatosis, iron overload, and combined disease.
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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
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
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 StudyAssessment of tumor recurrence in patients with colorectal cancer and elevated carcinoembryonic antigen level: FDG PET/CT versus contrast-enhanced 64-MDCT of the chest and abdomen.
The purpose of this study was to compare FDG PET/CT and contrast-enhanced 64-MDCT of the chest, abdomen, and pelvis in the detection of tumor recurrence in patients with colorectal cancer and an elevated level of carcinoembryonic antigen (CEA). ⋯ FDG PET/CT has higher sensitivity than MDCT in the identification of sites of recurrent and metastatic disease in patients with colorectal cancer and an elevated CEA level. The two techniques appear to have similar specificity.