MRI R2 and R2* mapping accurately estimates hepatic iron concentration in transfusion-dependent thalassemia and sickle cell disease patients

Wood, John C.; Enriquez, Cathleen; Ghugre, Nilesh R.; Tyzka, J. Michael; Carson, Susan; Nelson, Marvin D.; Coates, Thomas D.

doi:10.1182/blood-2004-10-3982

Cited by 923 publications

(1,201 citation statements)

References 37 publications

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“…MRI multi-echo T2* allows assessment of liver burden quantitatively and noninvasively. In clinical practice the T2* measurement is performed in a ROI of standard size, manually drawn in a homogeneous area of parenchyma without blood vessels (7,11). As with the single liver biopsy, the ROIbased method may suffer from sampling errors.…”

Section: Discussionmentioning

confidence: 99%

“…For the heart, a multislice approach was set up (6,7) to detect the heterogeneous myocardial iron distribution shown by histological studies (8,9). For the liver, a single transverse slice is traditionally acquired in clinical practice and the T2* measurement is performed in a region of interest (ROI) of the parenchyma (7,10,11). The use of the conventional single ROI technique has been partially due the fact that the early development of the T2* sequence in single echo multi-breathhold required approximately nine 10-s breathholds to acquire a single slice.…”

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confidence: 99%

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Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload

Meloni

Luciani

Positano

et al. 2011

Magnetic Resonance Imaging

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Purpose: To evaluate the effectiveness of the single ROI approach for the detection of hepatic iron burden in thalassemia major (TM) patients in respect to a whole liver measurement. Materials and Methods:Five transverse hepatic slices were acquired by a T2* gradient-echo sequence in 101 TM patients and 20 healthy subjects. The T2* value was calculated in a single region of interest (ROI) defined in the medium-hepatic slice. Moreover, the T2* value was extracted on each of the eight ROIs defined in the functionally independent segments. The mean hepatic T2* value was calculated.Results: For patients, the mean T2* values over segments VII and VIII were significantly lower. This pattern was substantially preserved in the two groups identified considering the T2* normal cutoff. All segmental T2* values were correlated with the single ROI T2* value. After the application of a correction map based on T2* fluctuations in the healthy subjects, no significant differences were found in the segmental T2* values.Conclusion: Hepatic T2* variations are low and due to artifacts and measurement variability. The single ROI approach can be adopted in the clinical arena, taking care to avoid the susceptibility artifacts, occurring mainly in segments VII and VIII.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload

Meloni

Luciani

Positano

et al. 2011

Magnetic Resonance Imaging

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“…Bone marrow iron stores were assessed semiquantitatively on Prussian-blue-stained marrow smears according to the following scale: grade 0= absent; 1=decreased; 2=normal; 3=increased; 4=markedly increased; 5=massively increased. LIC was determined quantitatively by T2*-weighted MRI as described previously [24][25][26]. An LIC >35-µmol/g liver tissue was considered as iron overload.…”

Section: Methodsmentioning

confidence: 99%

Deferasirox in MDS patients with transfusion-caused iron overload—a phase-II study

et al. 2008

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International audienceBlood transfusions represent a main component of supportive care in myelodysplastic syndromes (MDS). To avoid organ damage caused by transfusion-dependent iron overload, an adequate iron chelation therapy is required. Recently, a new oral iron chelator deferasirox (ICL670, Exjade®) has become available. A study was conducted to demonstrate the efficacy and tolerability of deferasirox in transfusion-dependent iron-overloaded patients with MDS. The efficacy of deferasirox was monitored by changes in serum ferritin, bone marrow iron, and liver iron concentration (LIC), as determined by T2*-weighted magnetic resonance imaging. Twelve patients with MDS of different subtypes (median age 76 years, range 53–91) were enrolled. Deferasirox administered in a once-daily dose of 20–30 mg/kg for 12 months was effective in reducing median ferritin concentration from 1,515 µg/L (range 665–6,900) to 413 µg/L (range 105–3,052). Within the first 4 weeks of treatment before the continuous decline of ferritin levels, the values markedly rose in eight of 12 patients. The median LIC declined from 315 to 230 µmol/g ( = 0.02) at the end of study, accompanied by a reduction of bone marrow siderosis. The most common adverse events were mild and transient gastrointestinal disturbances, skin rash, nonprogressive transient increases in serum creatinine and urine β2-microglobulin, and a temporary reduction of the creatinine clearance. The renal parameters normalized after end of treatment. No hematologic toxicities were observed. Deferasirox proved to be effective in transfusion-dependent iron overload in MDS by mobilizing iron deposits in liver and at least stabilizing iron stores in bone marrow

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“…R 2 * measurements were determined by collecting gradient echo multi‐echo MR images at increasing echo time as previously described 11, 45…”

Section: Methodsmentioning

confidence: 99%

Distinct Iron Deposition Profiles of Liver Zones in Various Models with Iron Homeostasis Disorders

et al. 2018

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Determination of iron accumulation is crucial in diagnosing the occurrence and progression of many liver‐ and iron‐related diseases. Thus far, little is known about the profiles of iron deposition in different liver zones, particularly under conditions with disordered iron homeostasis. Here, uneven iron distribution in livers of patients with hereditary hemochromatosis (HH) is uncovered, showing the region with the highest iron concentration near the entrance site of the portal vein and hepatic artery in contrast to the sites with the lowest iron concentration close to the distal edge. Distinct iron distribution profiles are also found throughout liver zones in wild‐type mice and various mouse models with iron metabolism disorders, including hemochromatosis (Hfe−/−), iron deficiency, and inflammation. Of note, similar findings observed in HH patients are further demonstrated in Hfe−/− mice. Moreover, the zones with greater iron accumulation appear to be more sensitive to iron changes, e.g., there is iron increase upon iron overload and iron loss in response to iron deficiency. Mechanistic investigation manifests that these differential iron changes in liver zones are subjected to the regulation by the hepcidin–ferroportin axis. Additionally, the data corroborate the reliability of magnetic resonance imaging (MRI) in recognizing the differential iron deposition profiles among liver zones.

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MRI R2 and R2* mapping accurately estimates hepatic iron concentration in transfusion-dependent thalassemia and sickle cell disease patients

Cited by 923 publications

References 37 publications

Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload

Single region of interest versus multislice T2* MRI approach for the quantification of hepatic iron overload

Deferasirox in MDS patients with transfusion-caused iron overload—a phase-II study

Distinct Iron Deposition Profiles of Liver Zones in Various Models with Iron Homeostasis Disorders

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