Quantitative CT: technique dependence of volume estimation on pulmonary nodules.
Summary of "Quantitative CT: technique dependence of volume estimation on pulmonary nodules."
Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and reconstruction parameters on accuracy (bias) and precision (variance) of the new techniques has not been fully investigated. To characterize the volume estimation performance dependence on these parameters, an anthropomorphic chest phantom containing synthetic nodules was scanned and reconstructed with protocols across various acquisition and reconstruction parameters. Nodule volumes were estimated by a clinical lung analysis software package, LungVCAR. Precision and accuracy of the volume assessment were calculated across the nodules and compared between protocols via a generalized estimating equation analysis. Results showed that the precision and accuracy of nodule volume quantifications were dependent on slice thickness, with different dependences for different nodule characteristics. Other parameters including kVp, pitch, and reconstruction kernel had lower impact. Determining these technique dependences enables better volume quantification via protocol optimization and highlights the importance of consistent imaging parameters in sequential examinations.
Medical Physics Graduate Program, Duke University, Durham, NC 27705, USA. Carl E Ravin Advanced Imaging Laboratories, Duke University, Durham, NC 27705, USA.
This article was published in the following journal.
Name: Physics in medicine and biology
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/22349265
- DOI: http://dx.doi.org/10.1088/0031-9155/57/5/1335
Medical and Biotech [MESH] Definitions
The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)
Volume of circulating ERYTHROCYTES . It is usually measured by RADIOISOTOPE DILUTION TECHNIQUE.
Multiple Pulmonary Nodules
A number of small lung lesions characterized by small round masses of 2- to 3-mm in diameter. They are usually detected by chest CT scans (COMPUTED TOMOGRAPHY, X-RAY). Such nodules can be associated with metastases of malignancies inside or outside the lung, benign granulomas, or other lesions.
Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.
Quantitative Trait Loci
Locations, on the GENOME, of GENES or other genetic elements that encode or control the expression of a quantitative trait (QUANTITATIVE TRAIT, HERITABLE).
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