AJR. American journal of roentgenology
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AJR Am J Roentgenol · Aug 2013
Evaluation of a limited three-slice head CT protocol for monitoring patients with ventriculoperitoneal shunts.
Patients with a ventriculoperitoneal shunt for the management of hydrocephalus often undergo multiple head CT examinations for assessment of shunt malfunction. The purpose of this study was to evaluate whether a limited three-slice CT protocol would consistently provide adequate information for the diagnosis of shunt malfunction with a decrease in effective dose. ⋯ Unenhanced head CT with a limited-slice protocol provides adequate diagnostic information for the diagnosis of shunt malfunction with a greater than 90% reduction in effective dose.
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AJR Am J Roentgenol · Jul 2013
Multicenter StudyEffective dose assessment for participants in the National Lung Screening Trial undergoing posteroanterior chest radiographic examinations.
The National Lung Screening Trial (NLST) is a multicenter randomized controlled trial comparing low-dose helical CT with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004, when 53,454 participants had been randomized at 33 screening sites. The objective of this study was to determine the effective radiation dose associated with individual chest radiographic screening examinations. ⋯ The effective dose for participant NLST chest radiographic examinations was determined and is of specific interest in relation to that associated with the previously published NLST low-dose CT examinations conducted during the trial.
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AJR Am J Roentgenol · Jul 2013
ReviewImaging after direct and indirect extracranial-intracranial bypass surgery.
The purpose of this article is to describe the imaging features of different types of surgical cerebral revascularization techniques. ⋯ Surgical cerebral revascularization involves direct and indirect techniques. Direct revascularization entails anastomosing a branch of the external carotid artery to a cerebral artery. Indirect revascularization involves delivering an extracranial vascular supply in proximity to the surface of the brain. The results of these techniques have distinctive imaging features.
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AJR Am J Roentgenol · Jul 2013
In vivo quantification of T1ρ in lumbar spine disk spaces at 3 T using parallel transmission MRI.
T1ρ MRI is an emerging, quantitative imaging modality that has been shown to correlate with proteoglycan content of disk material in vitro at 1.5 T. The purpose of this study is to quantify T1ρ values at all lumbar spine disk space levels at 3 T with parallel-transmission MRI in healthy adult volunteers. ⋯ T1ρ MRI in the lumbar spine with parallel transmission shows signifi-cant negative correlations with age at all disk space levels, which lends support to a potential role for T1ρ as a quantitative, in vivo biomarker of disk degeneration.
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AJR Am J Roentgenol · Jun 2013
Comparative StudyComparison of liquid crystal display monitors calibrated with gray-scale standard display function and with γ 2.2 and iPad: observer performance in detection of cerebral infarction on brain CT.
The purpose of the study was to compare observer performance in the detection of cerebral infarction on a brain CT using medical-grade liquid crystal display (LCD) monitors calibrated with the gray-scale standard display function and with γ 2.2 and using an iPad with a simulated screen setting. ⋯ Observer performance for detecting cerebral infarction on the LCD with γ 2.2 calibration was found to be similar to the LCD with gray-scale standard display function calibration. Although observer performance using the iPad was poorer than that using the other LCDs, the difference was small. Therefore, the iPad could not substitute for other LCD monitors. However, owing to the promising potential advantages of tablet PCs, such as portability, further examination is needed into the clinical use of tablet PCs.