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Blood, 15 January 2005, Vol. 105, No. 2, pp. 437-438. This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Porter, J. B. Search for Related Content PubMed Articles by Porter, J. B. Related Collections Related Article in Blood Online Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  TRANSFUSION MEDICINE Comment on St. Pierre et al, page 855 Liver iron measurement by MRI John B. Porter UNIVERSITY COLLEGE LONDON MEDICAL SCHOOL St. Pierre and colleagues have developed a magnetic resonance imaging (MRI)–based methodology for liver iron determination that is both accurate and sensitive over a wide concentration range of liver iron. The method offers the prospect of a reliable noninvasive determination of liver iron in most hospitals worldwide that have an up-to-date MRI facility. The monitoring of iron overload and its therapy has hitherto been troublesome because the tools available have been imprecise, difficult to use, or unavailable. Serum ferritin, used since the 1970s to estimate body iron loading is flawed because factors other than iron overload, such as inflammation and liver damage, affect plasma levels. Measurement of liver iron is clinically useful because total body iron can be precisely predicted mathematically from the liver iron concentration.1 Furthermore, sustained high levels of liver iron (> 15 mg/g dry weight) have been shown to be of prognostic value in predicting the cardiac complications of iron overload.2 A reliable and widely applicable method for measuring liver iron is therefore desirable in management of iron overload conditions. Liver biopsy can been used successfully to measure liver iron but is invasive and inconvenient to perform frequently. Measurement of liver iron by magnetic susceptometry using a SQUID (superconducting, quantum, interface device), although accurate and precise, requires specialized and expensive facilities, which are available in only 4 centers worldwide. The prospect of a simple measurement, which can be applied in any hospital having access to a suitable magnetic resonance imaging (MRI) scanner, is therefore highly desirable. A number of approaches to MRI estimation of tissue iron have previously been evaluated. Gradient echo sequences such as T2*3 are better suited to estimation of iron in tissues where iron concentrations are lower than in the liver, such as in the heart. This article and others4 suggest that spin echo (T2 or R2) sequences may offer the preferred approach for liver iron determination. In this issue of Blood the method of St. Pierre and colleagues appears to give excellent sensitivity and specificity over a wide concentration range of liver iron. Data obtained using this method can be analyzed at the facility where the data is acquired or can be sent electronically for central analysis, thereby offering improved quality control and eliminating the requirement to train local radiologists in data analysis. The current method requires 20 minutes for acquisition of data, which is slower than recently published T2* methodology using a single breath-hold.5 Development of a shorter acquisition time would be desirable and allow a wider range of patients to be measured, particularly young children. References Angelucci E, Brittenham GM, McLaren CE, et al. Hepatic iron concentration and total body iron stores in thalassemia major. N Engl J Med. 2000;343: 327-331.[Abstract/Free Full Text] Brittenham GM, Griffith PM, Nienhuis AW, et al. Efficacy of deferoxamine in preventing complications of iron overload in patients with thalassemia major. N Engl J Med. 1994;331: 567-573.[Abstract/Free Full Text] Anderson LJ, Holden S, Davis B, et al. Cardiovascular T2-star (T2*) magnetic resonance for the early diagnosis of myocardial iron overload. Eur Heart J. 2001;22: 2171-2179.[Abstract/Free Full Text] Gandon Y, Olivie D, Guyader D, et al. Non-invasive assessment of hepatic iron stores by MRI. Lancet. 2004;363: 357-362.[CrossRef][Medline] [Order article via Infotrieve] Westwood M, Anderson LJ, Firmin DN, et al. A single breath-hold multiecho T2* cardiovascular magnetic resonance technique for diagnosis of myocardial iron overload. J Magn Reson Imaging. 2003;18: 33-39.[CrossRef][Medline] [Order article via Infotrieve] CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? Related Article in Blood Online: Noninvasive measurement and imaging of liver iron concentrations using proton magnetic resonance Timothy G. St. Pierre, Paul R. Clark, Wanida Chua-anusorn, Adam J. Fleming, Gary P. Jeffrey, John K. Olynyk, Pensri Pootrakul, Erin Robins, and Robert Lindeman Blood 2005 105: 855-861. [Abstract] [Full Text] [PDF] This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Porter, J. B. Search for Related Content PubMed Articles by Porter, J. B. Related Collections Related Article in Blood Online Social Bookmarking                   What's this?

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