Magnetic measurement of human iron stores

Farrell, D. E.; Tripp, J. H.; Zanzucchi, P.E.; Harris, J. W.; Brittenham, Gary M.; Muir, Walter

doi:10.1109/tmag.1980.1060810

Cited by 47 publications

(22 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Today's clinical susceptometers use SQUID magnetic sensors and superconducting field coils enclosed in a liquid-helium dewar (Farrell et al 1980, Paulson et al 1991. This classic design has been validated by liver biopsy (Fischer et al 1992, Brittenham et al 1982, used clinically on hundreds of patients, and subjected to an intensive analysis of measurement errors (Fischer et al 1999(Fischer et al , 2002.…”

Section: Background and Motivationmentioning

confidence: 99%

See 1 more Smart Citation

Noninvasive liver-iron measurements with a room-temperature susceptometer

Avrin¹,

Kumar²

2012

Physiol. Meas.

View full text Add to dashboard Cite

Magnetic susceptibility measurements on the liver can quantify iron overload accurately and noninvasively. However, established susceptometer designs, using Superconducting QUantum Interference Devices (SQUIDs) that work in liquid helium, have been too expensive for widespread use. This paper presents a less expensive liver susceptometer that works at room temperature. This system uses oscillating magnetic fields, which are produced and detected by copper coils. The coil design cancels the signal from the applied field, eliminating noise from fluctuations of the source-coil current and sensor gain. The coil unit moves toward and away from the patient at 1 Hz, cancelling drifts due to thermal expansion of the coils. Measurements on a water phantom indicated instrumental errors less than 30 μg of iron per gram of wet liver tissue, which is small compared with other errors due to the response of the patient's body. Liver iron measurements on eight thalassemia patients yielded a correlation coefficient r=0.98 between the room-temperature susceptometer and an existing SQUID. These results indicate that the fundamental accuracy limits of the room-temperature susceptometer are similar to those of the SQUID.

show abstract

Section: Background and Motivationmentioning

confidence: 99%

“…Based on measurements by Farrell et al (1980), this model assumes that the response of the susceptometer falls off exponentially with distance. It represents the susceptometer response as…”

Section: 33mentioning

confidence: 99%

Noninvasive liver-iron measurements with a room-temperature susceptometer

Avrin¹,

Kumar²

2012

Physiol. Meas.

View full text Add to dashboard Cite

show abstract

“…Because the lungs (and possibly gas-filled intestines) are not directly beneath the detector, their contribution is small even though they can have a susceptibility substantially different from that of water. The susceptometer design and the differential measurement technique developed by Farrell and his colleagues [1,2,3,4] has been used as the basis for all commercial susceptometers [13]. The principal limitations on the use of susceptometry are in individuals who are obese, very small, or those who have metal implants or devices that may not be removed prior to the study.…”

Section: Principlesmentioning

confidence: 99%

“…Death is usually the result of cardiac failure. Bauman and Harris [2] originally proposed that the paramagnetic properties of storage iron (ferritin and hemosiderin) could be used to assess the body iron burden non-invasively. Harris and his co-workers subsequently developed low-transition-temperature (low-T C ; operating at 4°K in liquid helium) superconducting quantum interference device (SQUID) biosusceptometry as a clinical method for the measurement of hepatic iron stores [3].…”

Section: Introductionmentioning

confidence: 99%

SQUID biosusceptometry in the measurement of hepatic iron

Sheth

2003

Ped Radiol

View full text Add to dashboard Cite

Individuals with primary or secondary abnormalities of iron metabolism, such as hereditary hemochromatosis and transfusional iron loading, may develop potentially lethal systemic iron overload. Over time, this excess iron is progressively deposited in the liver, heart, pancreas, and other organs, resulting in cirrhosis, heart disease, diabetes and other disorders. Unless treated, death usually results from cardiac failure. The amount of iron in the liver is the best indicator of the amount of iron in the whole body. At present, the only sure way to measure the amount of iron in the liver is to remove a sample of the liver by biopsy. Iron stored in the liver can be magnetized to a small degree when placed in a magnetic field. The amount of magnetization is measured by our instrument, called a superconducting quantum interference device (SQUID) susceptometer. In patients with iron overload, our previous studies have shown that magnetic measurements of liver iron in patients with iron overload are quantitatively equivalent to biochemical determinations on tissue obtained by biopsy. The safety, ease, rapidity, and comfort of magnetic measurements make frequent, serial studies technically feasible and practically acceptable to patients.

show abstract

“…System design and the ambient fields in the vicinity of the probe determine noise levels. With the use of gradiometer configuration pickup coils, signal levels on the order of 2 ϫ 10 −14 T / cm are readily achievable 11 in an unscreened relatively low noise environment.…”

Section: Introductionmentioning

confidence: 99%

Detection of magnetically enhanced cancer tumors using SQUID magnetometry: A feasibility study

Kenning

Rodriguez

Zotev

et al. 2004

Review of Scientific Instruments

View full text Add to dashboard Cite

Nanoparticles bound to various biological molecules and pharmacological agents can be administered systemically, to humans without apparent toxicity. This opens an era in the targeting of specific tissues and disease processes for noninvasive imaging and treatment. An important class of particles used predominantly for magnetic resonance imaging is based on iron-oxide ferrites. We performed computer simulations using experimentally determined values for concentrations of superparamagnetic particles achievable in specific tissues of the mouse in vivo and concentrations of particles linked to monoclonal antibodies specific to antigens of two human cancer cell lines in vitro. An instrument to target distance of 12cm, into the body, was selected as relevant to our goal of developing a rapid inexpensive method of scanning the body for occult disease. The simulations demonstrate the potential feasibility of superconducting quantum interference device magnetometry to detect induced magnetic fields in focal concentrations of superparamagnetic particles targeted, in vivo, to sites of disease.

show abstract

Magnetic measurement of human iron stores

Cited by 47 publications

References 5 publications

Noninvasive liver-iron measurements with a room-temperature susceptometer

Noninvasive liver-iron measurements with a room-temperature susceptometer

SQUID biosusceptometry in the measurement of hepatic iron

Detection of magnetically enhanced cancer tumors using SQUID magnetometry: A feasibility study

Contact Info

Product

Resources

About