Bjoern Schoennagel, Presenter: Nothing to Disclose

Chressen Catharina Much, Abstract Co-Author: Nothing to Disclose

Roland Fischer Dipl Phys, Abstract Co-Author: Nothing to Disclose

Gerhard B. Adam MD, Abstract Co-Author: Nothing to Disclose

Ulrike Wedegaertner MD, Abstract Co-Author: Nothing to Disclose

Jin Yamamura MD, Abstract Co-Author: Nothing to Disclose

The gestational condition of neonantal hemochromatosis (NH) is characterized by liver failure associated with intra- and extrahepatic iron accumulation and a poor outcome. Enabling antenatal initiation of immunomodulating therapy, intrauterine diagnosis of fetal hepatic and tissue iron overload is mandatory. Thus, demonstrating the feasibility of fetal liver and spleen iron quantification in utero by MRI may add valuable information to this disease.  

The study was approved by the local animal protection authorities. 3 healthy fetal sheep (gestational age 112-122 days) underwent MRI on 1.5 T imager for liver and spleen R2* measurements using a breath triggered (ewe) multi-echo sequence (TE 4.6-54.1 ms, 12 echoes, TR 578 ms, flip angle 20˚, pixel bandwidth 283Hz/pixel). The transverse relaxation rate R2* was determined from a mono-exponential fit with constant signal level offset to the echo-time dependent signal intensities averaged over one liver and spleen slice (thickness 5.5 mm). Calibration of R2* was adopted from human liver and spleen iron measurements.

All obtained images were of very good quality, fetal livers and spleens could easily be identified. Fetal liver R2* ranged from 28.7-36.6 s-1 (SD±0.4-3.1), R2* of the fetal spleens ranged from 37.4-51.0 s-1 (SD±1.7-2.4). The corresponding liver iron concentration (LIC) was below 50 in two and 130±12 µg/gwet weight in one fetus. The corresponding spleen iron concentration (SIC) ranged from 141-308 µg/gw.w. (SD±14-53).

Feasibility of intrauterine liver and spleen iron quantification was demonstrated performing fetal MRI in a sheep model. Iron concentrations in the healthy fetuses` spleens were slightly larger than in the livers, probably due to the physiological antenatal extramedullary hematopoesis and increased erythropoietic activity.

Transferring the successful intrauterine quantification of fetal LIC and SIC in sheep to human pregnancies with suspected NH could enable early diagnosis and thus therapy with improvement of prognosis

Schoennagel, B, Much, C, Fischer, R, Adam, G, Wedegaertner, U, Yamamura, J, Antenatal Liver and Spleen Iron Quantification in a Sheep Model.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014151.html