Effect of NC100150 injection on the1H NMR linewidth of human whole blood ex vivo: Dependency on blood oxygen tension

Bjørnerud, Atle; Briley‐Saebo, Karen C.; Johansson, Lars; Kellar, Kenneth E.

doi:10.1002/1522-2594(200011)44:5<803::aid-mrm19>3.0.co;2-k

Cited by 27 publications

(33 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Intravascular nanoparticle-based contrast agents are characterized by a large magnetic moment and a high dipolar relaxivity relative to traditional paramagnetic agents (1,2). The large magnetic moment is an advantage in T* 2 perfusion imaging, since larger 1/T* 2 changes can be achieved for a given contrast agent concentration compared to traditional gadolinium-based agents (3).…”

contrasting

confidence: 58%

“…Furthermore, the tracer concentration is assumed to be proportional to the first-pass change in 1/T* 2 (4,5). In single-echo steady-state sequences, the relationship between 1/T* 2 changes and SI changes is given by: ⌬R* 2 ͑t͒ ϭ 1 TE ⅐ ͓log e ͑S͑0͒/S͑t͒͒ ϩ log e ͑E͑t͒/E͑0͔͒͒ [1] where R* 2 ϭ 1/T * 2 , TE is the echo time, and S(0) and S(t) are the SIs measured at baseline and at time t during the contrast agent passage, respectively. The factors E(0) and E(t) describe the T 1 contribution to the MR signal before and at time t during contrast agent passage, and this term is generally assumed to be negligible in T* 2 perfusion sequences.…”

mentioning

confidence: 99%

“…With this assumption, Eq. [1] reduces to the more familiar expression ⌬R* 2 ͑t͒ ϭ 1 TE ⅐ ͓log e ͑S͑0͒/S͑t͔͒͒. [2] Using Eq.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T₁ relaxation on the first‐pass response

Bjørnerud

Johansson

Åhlström

2002

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

Quantitative perfusion measurements require accurate knowledge of the correlation between first-pass signal changes and the corresponding tracer concentration in tissue. In the present study, a detailed analysis of first-pass renal cortical changes in T 1 and T * 2 following bolus injection of the iron oxide nanoparticle NC100150 Injection was investigated in a pig model using a double-echo gradient-echo sequence. The estimated change in 1/T* 2 during first pass calculated from single-echo sequences was compared to the true double-echo-derived 1/T* 2 curves. Using a single-echo (TE ‫؍‬ 6 ms) spoiled gradient-echo sequence, the first-pass 1/T* 2 response following a bolus injection of 1 mg Fe/kg of NC100150 Injection was significantly underestimated due to counteracting T 1 effects. Signal response simulations showed that the relative error in the first-pass response decreased with increasing TE and contrast agent dose. However, both the maximum TE and the maximum dose are limited by excessive cortical signal loss, and the maximum TE is further limited by high temporal resolution requirements. The problem of T 1 contamination can effectively be overcome by using a double-echo gradient-echo sequence. This yields a first-pass response that truly reflects the tissue tracer concentration, which is a critical requirement for quantitative renal perfusion assessment. Magn Reson Med 47:298 -304, 2002.

show abstract

contrasting

confidence: 58%

mentioning

confidence: 99%

See 1 more Smart Citation

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T₁ relaxation on the first‐pass response

Bjørnerud

Johansson

Åhlström

2002

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

show abstract

“…Contrast agent NC100150 Injection (Clariscan, Amersham Health, Oslo, Norway) is a monocrystalline superparamagnetic iron oxide nanoparticle with a mean core diameter of 5.6±1.2 nm and a saturation magnetisation of 8.61×10 −2 Am 2 /g Fe (Bjornerud et al 2000(Bjornerud et al , 2002. The corresponding hydrated particle diameter is 12.1±0.2 nm, measured by photon correlation spectroscopy (Bjornerud et al 2002).…”

Section: Methodsmentioning

confidence: 99%

“…The corresponding hydrated particle diameter is 12.1±0.2 nm, measured by photon correlation spectroscopy (Bjornerud et al 2002). The longitudinal (r 1 ) and transverse (r 2 ) relaxivities in water at 37°C and 20 MHz are 21.8 and 35.3 s −1 mM −1 , respectively (Bjornerud et al 2000). Methoxy (PEG) phosphate 2000 is adsorbed onto the surface of the iron oxide core at a concentration of 0.2 mg/mg Fe.…”

Section: Methodsmentioning

confidence: 99%

Hepatic cellular distribution and degradation of iron oxide nanoparticles following single intravenous injection in rats: implications for magnetic resonance imaging

Briley‐Saebo

Bjørnerud

Grant³

et al. 2004

Cell and Tissue Research

Self Cite

213

193

View full text Add to dashboard Cite

The purpose of this study was to determine the cellular distribution and degradation in rat liver following intravenous injection of superparamagnetic iron oxide nanoparticles used for magnetic resonance imaging (NC100150 Injection). Relaxometric and spectrophotometric methods were used to determine the concentration of the iron oxide nanoparticles and their degradation products in isolated rat liver parenchymal, endothelial and Kupffer cell fractions. An isolated cell phantom was also constructed to quantify the effect of the degradation products on the loss of MR signal in terms of decreased transverse relaxation times, T2*. The results of this study show that iron oxide nanoparticles found in the NC100150 Injection were taken up and distributed equally in both liver endothelial and Kupffer cells following a single 5 mg Fe/kg body wt. bolus injection in rats. Whereas endothelial and Kupffer cells exhibited similar rates of uptake and degradation, liver parenchymal cells did not take up the NC100150 Injection iron oxide particles. Light-microscopy methods did, however, indicate an increased iron load, presumably as ferritin/hemosiderin, within the hepatocytes 24 h post injection. The study also confirmed that compartmentalisation of ferritin/hemosiderin may cause a significant decrease in the MRI signal intensity of the liver. In conclusion, the combined results of this study imply that the prolonged presence of breakdown product in the liver may cause a prolonged imaging effect (in terms of signal loss) for a time period that significantly exceeds the half-life of NC100150 Injection iron oxide nanoparticles in liver.

show abstract

Regulatory updates

2005

Environ. Prog.

View full text Add to dashboard Cite

Effect of NC100150 injection on the1H NMR linewidth of human whole blood ex vivo: Dependency on blood oxygen tension

Cited by 27 publications

References 15 publications

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T₁ relaxation on the first‐pass response

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T₁ relaxation on the first‐pass response

Hepatic cellular distribution and degradation of iron oxide nanoparticles following single intravenous injection in rats: implications for magnetic resonance imaging

Regulatory updates

Contact Info

Product

Resources

About

Effect of NC100150 injection on the1H NMR linewidth of human whole blood ex vivo: Dependency on blood oxygen tension

Cited by 27 publications

References 15 publications

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T1 relaxation on the first‐pass response

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T1 relaxation on the first‐pass response

Hepatic cellular distribution and degradation of iron oxide nanoparticles following single intravenous injection in rats: implications for magnetic resonance imaging

Regulatory updates

Contact Info

Product

Resources

About

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T₁ relaxation on the first‐pass response

Renal T perfusion using an iron oxide nanoparticle contrast agent—influence of T₁ relaxation on the first‐pass response