Computed Tomography for Determining Liver Iron Content in Primary Haemochromatosis

Chapman, Roger W.; Williams, G.R.; Gm, Bydder; Dick, Robert; Sherlock, Sheila; Kreel, L.

doi:10.1097/00004728-198102000-00036

Cited by 8 publications

(10 citation statements)

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“…One of the initial applications developed for material decomposition with DECT was the quantification of liver iron stores [9, 19, 20]. Excessive body iron stores may be due to a primary (idiopathic) cause related to excessive iron absorption from intestinal mucosa, or secondary due to chronic large volume blood transfusion, often associated with hematologic disorders.…”

Section: Unenhanced Dectmentioning

confidence: 99%

“…The liver iron concentration is then multiplied by the 3D volume of the liver to calculate the liver iron stores. In early studies, excellent correlation (r=0.993) was seen between biopsy and DECT determination of liver iron [20], which was a marked improvement over what is possible with conventional single energy CT due to the variable contribution of liver fat which may occur concurrently with iron deposition. In addition to the liver, DECT allows for quantification of iron deposition in other tissues including the myocardium [21].…”

Section: Unenhanced Dectmentioning

confidence: 99%

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Dual-Energy and Low-kVp CT in the Abdomen

Yeh

Shepherd

Wang

et al. 2009

American Journal of Roentgenology

210

107

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Low kVp settings provide high conspicuity of contrast materials at CT but may result in high image noise, particularly in larger patients. Material decomposition at dual energy CT can differentiate renal stones by their composition, quantify tissue iron stores, improve the detection of pathologic hyperenhancement, and reduce contrast material and radiation dose compared to conventional CT. Further clinical research and technique refinement will be needed as the usage of these exiciting technologies spreads.

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Section: Unenhanced Dectmentioning

confidence: 99%

Section: Unenhanced Dectmentioning

confidence: 99%

Dual-Energy and Low-kVp CT in the Abdomen

Yeh

Shepherd

Wang

et al. 2009

American Journal of Roentgenology

210

107

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show abstract

“…This is the first large study comparing QCT estimates of liver attenuation with validated measurements of LIC in humans. Pilot studies in humans and dogs in the early1980’s first demonstrated the potential of dual‐energy QCT for noninvasive liver iron measurement (Chapman et al , 1980; Goldberg et al , 1982). Since that time, QCT studies in humans have been limited by small sample size, lack of standard QCT phantom corrections, and absence of a validated independent metric of liver iron (Howard et al , 1983; Guyader et al , 1989; Olivieri et al , 1989; Bonkovsky et al , 1990; Chezmar et al , 1990; Harada et al , 1992).…”

Section: Discussionmentioning

confidence: 99%

“…It is well‐validated but remains limited by cost and availability. Quantitative computed tomography (QCT) was proposed as a means to estimate liver iron concentration (LIC) 30 years ago (Chapman et al , 1980; Goldberg et al , 1982), but there has been surprisingly limited human validation (Chapman et al , 1980). Compared to MRI, QCT has the advantage of potential superior availability, speed, ease of use, and cost.…”

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confidence: 99%

Quantitative computed tomography assessment of transfusional iron overload

Wood¹,

Gera³

et al. 2011

Br J Haematol

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Summary Quantitative computed tomography (QCT) has been proposed for iron quantification for more than 30 years, however there has been little clinical validation. We compared liver attenuation by QCT with magnetic resonance imaging (MRI)‐derived estimates of liver iron concentration (LIC) in 37 patients with transfusional siderosis. MRI and QCT measurements were performed as clinically indicated monitoring of LIC and vertebral bone‐density respectively, over a 6‐year period. Mean time difference between QCT and MRI studies was 14 d, with 25 studies performed on the same day. For liver attenuation outside the normal range, attenuation values rose linearly with LIC (r2 = 0·94). However, intersubject variability in intrinsic liver attenuation prevented quantitation of LIC <8 mg/g dry weight of liver, and was the dominant source of measurement uncertainty. Calculated QCT and MRI accuracies were equivalent for LIC values approaching 22 mg/g dry weight, with QCT having superior performance at higher LIC’s. Although not suitable for monitoring patients with good iron control, QCT may nonetheless represent a viable technique for liver iron quantitation in patients with moderate to severe iron in regions where MRI resources are limited because of its low cost, availability, and high throughput.

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“…Certain tissues can also be differentiated if their rates of decrease of x-ray attenuation change with increasing x-ray photon energy differ sufficiently (e.g., iron deposits in hemochromatosis (83,84). For best results, these methods either require a monochromatic x-ray source (which is best achieved with synchrotron radiation, but quasi-monochromatic spectra can be achieved with diffraction-type filtering of the bremsstrahlung x-ray emission from a roentgen x-ray source) or energy-selective x-ray detection.…”

Section: Introductionmentioning

confidence: 99%

Small-Animal Molecular Imaging Methods

Kemp¹,

Epstein²,

Catana³

et al. 2010

J Nucl Med

111

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Rationale The ability to trace or identify specific molecules within a specific anatomic location provides insight into metabolic pathways, tissue components and tracing of solute transport mechanisms. With the increasing use of small animals for research such imaging must have sufficiently high spatial resolution to allow anatomic localization as well as sufficient specificity and sensitivity to provide an accurate description of the molecular distribution and concentration. Methods Imaging methods based on electromagnetic radiation, such as PET, SPECT, MRI and CT, are increasingly applicable due to recent advances in novel scanner hardware, image reconstruction software and availability of novel molecules which have enhanced sensitivity in these methodologies. Results Micro-PET has been advanced by development of detector arrays that provide higher resolution and positron emitting elements that allow new molecular tracers to be labeled. Micro-MRI has been improved in terms of spatial resolution and sensitivity by increased magnet field strength and development of special purpose coils and associated scan protocols. Of particular interest is the associated ability to image local mechanical function and solute transport processes which can be directly related to the molecular information. This is further strengthened by the synergistic integration of the PET with MRI. Micro-SPECT has been improved by use of coded aperture imaging approaches as well as image reconstruction algorithms which can better deal with the photon limited scan data. The limited spatial resolution can be partially overcome by integrating the SPECT with CT. Micro-CT by itself provides exquisite spatial resolution of anatomy, but recent developments of high spatial resolution photon counting and spectrally-sensitive imaging arrays, combined with x-ray optical devices, have promise for actual molecular identification by virtue of the chemical bond lengths of molecules, especially of bio-polymers. Conclusion With the increasing use of small animals for evaluating new clinical imaging techniques as well as providing increased insights into patho-physiological phenomena, the availability of improved detection systems, scanning protocols and associated software, the repertoire of molecular imaging is greatly increased in sensitivity and specificity.

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Computed Tomography for Determining Liver Iron Content in Primary Haemochromatosis

Cited by 8 publications

References 0 publications

Dual-Energy and Low-kVp CT in the Abdomen

Dual-Energy and Low-kVp CT in the Abdomen

Quantitative computed tomography assessment of transfusional iron overload

Small-Animal Molecular Imaging Methods

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