Nuclear magnetic resonance imaging of experimentally induced liver disease.

Abstract

Experimental animal models of hepatitis, fatty liver, and hepatic iron overload were evaluated using a 3.5-kGauss nuclear magnetic resonance (NMR) imaging system. Increases in image intensity measurements and in T2 relaxation times equalled the sensitivity of histologic findings for the detection of early stages of hepatitis. A significant shift in T1 relaxation times characterized the early stages of hepatic necrosis. Liver triglyceride content correlated significantly with increases in NMR intensity measurements (p less than 0.01); however, changes in liver water content had a much greater influence on intensity, T1, and T2. Thus, it may be possible to distinguish hepatitis from benign fatty liver. Liver iron content correlated with decreases in NMR intensity measurements (p less than 0.001), and iron levels as low as 1.2 mg/g were detected. NMR may more specifically identify hepatocellular iron overload than do other techniques that do not distinguish hepatocellular from reticuloendothelial iron.

MRI of hepatic iron deposition in patients with renal transplant

“…Noninvasive assessment of iron overload is primarily based on serum ferritin concentration with the assumption that 1 gg/ml of serum ferritin is equivalent to 140 gg/kg of body weight [9,13,25]. Serum ferritin concentrations, however, are influenced by the presence of inflammatory states, neoplastic disorders, and hepatocellular disease.…”

“…Previous studies have documented diminished hepatic signal intensity as a very specific sign of hemosiderosis [9][10][11][12][13][14][15][16][17][18][19]. This prompted us to evaluate by MR a group of renal transplant patients to determine the presence of excess iron deposition and correlate the hemosiderosis with the number of transplants, years of hemodialysis and chronic renal failure, histocompatibility alleles (HLA) [20], and the number of blood transfusions.…”

Protein Cages as Multimode Imaging Agents

“…This weakly superparamagnetic ferrihydrite [37] functions as an endogenous contrast agent that significantly shortens the T2 of surrounding water protons. Since iron is well known to play an important role in a number of diseases, endogenous ferritin in humans has been considered as a useful marker for MRI examination to assess the amount of iron in liver, spleen, and brain [38][39][40]. In addition, ferritin has recently been proposed as a reporter protein to monitor transgene expression using MRI [41,42].…”

Magnetic field dependence of solvent proton relaxation in aqueous solutions of Fe3+ complexes

“…Gd3+ and Mn2+ ions, introduced either as solutions of their salts, or complexed with multidentate chelates, have been used in animal studies ( I , 3,5 ) and in humans (6,71, and Fe3+, taken orally in the form of a commercially available dietary supplement, has been suggested as potentially useful for visualizing the gastrointestinal tract (4).…”