AJR. American journal of roentgenology
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Dual-energy CT (DECT) is an innovative imaging technique that operates on the basic principle of application of two distinct energy settings that make the transition from CT attenuation-based imaging to material-specific or spectral imaging. The purpose of this review is to describe the use of DECT in oncology. ⋯ Applications of DECT in clinical practice are based on two capabilities: material differentiation and material identification and quantification. The capability of obtaining different material-specific datasets (iodine map, virtual unenhanced, and monochromatic images) in the same acquisition can improve lesion detection and characterization. This approach can also affect evaluation of the response to therapy and detection of oncology-related disorders. DECT is an innovative imaging technique that can dramatically affect the care of oncologic patients.
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AJR Am J Roentgenol · Nov 2012
Comparative StudyWhole-body diffusion-weighted MRI compared with (18)F-NaF PET/CT for detection of bone metastases in patients with high-risk prostate carcinoma.
The purpose of this study was to evaluate the accuracy of whole-body diffusion-weighted MRI (DWI) and (18)F-NaF PET/CT for detection of bone metastases in patients with high-risk prostate cancer. ⋯ We believe (18)F-NaF PET/CT is a sensitive modality for detection of bone metastases caused by prostate cancer. Whole-body DWI shows a higher specificity but lower sensitivity than (18)F-NaF PET/CT. Future studies with a larger patient cohort along with analyses of costs and clinical availability are needed before implementation of these methods can be considered.
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The purpose of this article is to give a brief overview of the technical background of dual-energy CT (DECT) imaging and to review various DECT applications in the abdomen that are currently available for clinical practice. In a review of the recent literature, specific DECT applications available for abdominal organs, liver, pancreas, kidneys including renal stones, and adrenal glands, will be discussed in light of reliability and clinical usefulness in replacing true unenhanced imaging, increased lesion conspicuity, iodine extraction, and improved tissue/material characterization (e.g., renal stone composition). Radiation dose considerations will be addressed in comparison with standard abdominal imaging protocols. ⋯ Modern DECT applications for the abdomen expand the use of CT and enable advanced quantitative methods in the clinical routine on the basis of differences in material attenuation observed by imaging at two different distinct photon energies.
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AJR Am J Roentgenol · Nov 2012
High-resolution CT findings in fibrotic idiopathic interstitial pneumonias with little honeycombing: serial changes and prognostic implications.
This retrospective study evaluates serial changes of lung abnormalities on high-resolution CT (HRCT) and clarifies prognostic determinants among CT findings in fibrotic idiopathic interstitial pneumonias (IIPs) with little honeycombing. ⋯ Even in cases of fibrotic IIP with little honeycombing, serial CT reveals an increase in the extent of honeycombing and reticulation and a decrease in extent of GGO. Overall extent of lung fibrosis on the baseline CT examination appears predictive of survival in fibrotic IIP with little honeycombing.
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The introduction of dual-energy CT (DECT) has ushered in the ability of material differentiation and tissue characterization beyond the traditional CT attenuation scale. This quality has been exploited for visualizing and quantifying the specific tissue content using radiographic contrast agents, such as iodine-based contrast media or inhaled xenon gas. Applications of this paradigm in the thorax include characterization of the pulmonary blood pool in the setting of acute or chronic pulmonary embolism (PE) and characterization of diseases of the lung parenchyma. Selective xenon detection is being explored for imaging of lung ventilation. In addition, the usefulness of DECT-based selective iodine uptake measurements has been described for the diagnosis and surveillance of thoracic malignancies. This article reviews the current applications of DECT-based imaging techniques in the chest with an emphasis on the diagnosis and characterization of pulmonary thromboembolic disorders. ⋯ DECT can provide both anatomic and functional information about the lungs in a variety of pulmonary disease states based on a single contrast-enhanced CT examination. This quality has been shown to improve the diagnosis of acute and chronic PEs, other vascular disorders, lung malignancies, and parenchymal diseases. Further developments in DECT techniques and CT scanner technology will further foster and enhance the utility of this application and open new avenues in lung imaging.