Giant Hemosiderotic Adenodermatofibroma: A Case Report and Review of the Literature.

ABSTRACT: Adenodermatofibromas are an extremely rare subtype of dermatofibroma (DF) characterized by a dermal proliferation of spindle-shaped fibroblasts and histocytes, dilated glandular structures with apocrine secretion, and prominent vascular proliferation, with or without hemosiderotic features. We describe a recent extraordinary case of a hemosiderotic adenodermatofibroma in a 25-year-old female. We review histologic findings and theories behind etiology, as well as review the spectrum of clinical presentations for this lesion. We also discuss imaging findings that may make identification of these entities challenging.

In vivo calibration of the T2* cardiovascular magnetic resonance method at 1.5 T for estimation of cardiac iron in a minipig model of transfusional iron overload.

BACKGROUND: Non-invasive estimation of the cardiac iron concentration (CIC) by T2* cardiovascular magnetic resonance (CMR) has been validated repeatedly and is in widespread clinical use. However, calibration data are limited, and mostly from post-mortem studies. In the present study, we performed an in vivo calibration in a dextran-iron loaded minipig model. METHODS: R2* (= 1/T2*) was assessed in vivo by 1.5 T CMR in the cardiac septum. Chemical CIC was assessed by inductively coupled plasma-optical emission spectroscopy in endomyocardial catheter biopsies (EMBs) from cardiac septum taken during follow up of 11 minipigs on dextran-iron loading, and also in full-wall biopsies from cardiac septum, taken post-mortem in another 16  minipigs, after completed iron loading. RESULTS: A strong correlation could be demonstrated between chemical CIC in 55 EMBs and parallel cardiac T2* (Spearman rank correlation coefficient 0.72, P < 0.001). Regression analysis led to [CIC] = (R2* - 17.16)/41.12 for the calibration equation with CIC in mg/g dry weight and R2* in Hz. An even stronger correlation was found, when chemical CIC was measured by full-wall biopsies from cardiac septum, taken immediately after euthanasia, in connection with the last CMR session after finished iron loading (Spearman rank correlation coefficient 0.95 (P < 0.001). Regression analysis led to the calibration equation [CIC] = (R2* - 17.2)/31.8. CONCLUSIONS: Calibration of cardiac T2* by EMBs is possible in the minipig model but is less accurate than by full-wall biopsies. Likely explanations are sampling error, variable content of non-iron containing tissue and smaller biopsies, when using catheter biopsies. The results further validate the CMR T2* technique for estimation of cardiac iron in conditions with iron overload and add to the limited calibration data published earlier.

Renal hemosiderosis presenting with acute kidney Injury and macroscopic hematuria in Immunoglobulin A nephropathy: a case report.

BACKGROUND: Macroscopic hematuria-associated acute kidney injury (AKI) is a well-known complication of immunoglobulin A (IgA) nephropathy. In such cases, intratubular obstruction by red blood cell (RBC) casts and acute tubular necrosis are mainly observed pathologically. Herein, we report the case of a patient with IgA nephropathy presenting with AKI following an episode of macrohematuria. The patient presented with severe renal tubular hemosiderosis and acute tubular necrosis and without any obvious obstructive RBC casts. CASE PRESENTATION: A 68-year-old woman, who was diagnosed with IgA nephropathy on renal biopsy 6 years ago, was admitted to our hospital after an episode of macroscopic glomerular hematuria and AKI following upper respiratory tract infection. Renal biopsy showed mesangial proliferation of the glomeruli, including crescent formation in 17 % of the glomeruli, and acute tubular necrosis without obvious hemorrhage or obstructive RBC casts. The application of Perls' Prussian blue stain showed hemosiderin deposition in the renal proximal tubular cells. Immunofluorescence showed granular mesangial deposits of IgA and C3. Based on these findings, she was diagnosed with acute tubular necrosis with a concurrent IgA nephropathy flare-up. Moreover, direct tubular injury by heme and iron was considered to be the cause of AKI. She was treated with intravenous pulse methylprednisolone followed by oral prednisolone. Thereafter, the gross hematuria gradually faded, and her serum creatinine levels decreased. CONCLUSIONS: IgA nephropathy presenting with acute kidney injury accompanied by macrohematuria may cause renal hemosiderosis and acute tubular necrosis without obstructive RBC casts. Hemosiderosis may be a useful indicator for determining the pathophysiology of macroscopic hematuria-associated AKI. However, renal hemosiderosis may remain undiagnosed. Thus, Perls' Prussian blue iron staining should be more widely used in patients presenting with hematuria.

Autoimmunity and Delayed Diagnosis in Pediatric Idiopathic Pulmonary Hemosiderosis.

Idiopathic pulmonary hemosiderosis is characterized by a triad of iron-deficiency anemia, hemoptysis, and radiographic diffuse lung infiltrates. However, the inconsistent initial presentation in children may cause a significant delay in diagnosis. Autoimmune reactivity seems to be the most acceptable theory of pathogenesis. We reported an 8-year-old boy presenting with a cough, fever, and difficulty breathing with a history of iron-deficiency anemia and an abnormal autoimmune response in the last 3 years. Perinuclear antineutrophil cytoplasmic antibodies were positive and chest computed tomography revealed patchy ground glass haziness. Bronchoalveolar lavage fluid showed hemosiderin-laden macrophages. The respiratory symptoms improved with oral corticosteroids.

Idiopathic pulmonary hemosiderosis - A rare cause of chronic anemia.

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease marked by alveolar bleeding and accumulation of hemosiderin in the lungs. Here we present three cases of IPH. The first case is of a 26-year-old male with anemia, hemoptysis and dyspnea. Bronchoscopy confirmed diffuse alveolar hemorrhage (DAH). A diagnosis of IPH was made after ruling out other causes of DAH and observing good response to steroids. The patient's condition improved with prednisolone and azathioprine. The second case is of 26-year-old female with severe anemia. Imaging suggested IPH and lung biopsy confirmed it. She died shortly afterwards. The third case is of a 7-year-old male with chronic anemia. CT was suggestive of IPH and lung biopsy confirmed the diagnosis. Later, patient developed posterior reversible encephalopathy syndrome (PRES). This patient is stable on azathioprine and prednisolone. We aim to emphasize the importance of considering IPH as a differential in patients with DAH or chronic anemia.

Amniotic epithelial cells damage by oxidative stress in cases of diffuse chorioamniotic hemosiderosis.

The amniotic membrane plays an important role in the physiological maintenance and protection of the embryo. Indeed, dysfunction of the amniotic membrane is thought to have an adverse effect on the continuation of pregnancy. In this report, we examined the pathological changes in the amniotic epithelium in three cases of diffuse chorioamniotic hemosiderosis (DCH) and investigated the cause of necrosis of the amniotic epithelial cells and its relationship with oligohydramnios. Diffuse chorioamniotic hemosiderosis was confirmed in all three cases. More extensive amniotic epithelial necrosis led to more severe hemosiderosis. Immunostaining for 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress, was positive in the amniotic epithelial cells. We speculate that oxidative DNA damage of the amniotic epithelium occurs by decomposition products of blood cells in cases accompanying subchorionic hematomas and pathological DCH. Furthermore, disorder of the amniotic epithelium may disrupt the balance of the amniotic fluid volume and cause oligohydramnios.

Post-mortem study of the association between cardiac iron and fibrosis in transfusion dependent anaemia.

BACKGROUND: Heart failure related to cardiac siderosis remains a major cause of death in transfusion dependent anaemias. Replacement fibrosis has been reported as causative of heart failure in siderotic cardiomyopathy in historical reports, but these findings do not accord with the reversible nature of siderotic heart failure achievable with intensive iron chelation. METHODS: Ten whole human hearts (9 beta-thalassemia major, 1 sideroblastic anaemia) were examined for iron loading and fibrosis (replacement and interstitial). Five had died from heart failure, 4 had cardiac transplantation for heart failure, and 1 had no heart failure (death from a stroke). Heart samples iron content was measured using atomic emission spectroscopy. Interstitial fibrosis was quantified by computer using picrosirius red (PSR) staining and expressed as collagen volume fraction (CVF) with normal value for left ventricle <3%. RESULTS: The 9 hearts affected by heart failure had severe iron loading with very low T2* of 5.0 ± 2.0 ms (iron concentration 8.5 ± 7.0 mg/g dw) and diffuse granular myocardial iron deposition. In none of the 10 hearts was significant macroscopic replacement fibrosis present. In only 2 hearts was interstitial fibrosis present, but with low CVF: in one patient with no cardiac siderosis (death by stroke, CVF 5.9%) and in a heart failure patient (CVF 2%). In the remaining 8 patients, no interstitial fibrosis was seen despite all having severe cardiac siderosis and heart failure (CVF 1.86% ±0.87%). CONCLUSION: Replacement cardiac fibrosis was not seen in the 9 post-mortem hearts from patients with severe cardiac siderosis and heart failure leading to death or transplantation, which contrasts markedly to historical reports. Minor interstitial fibrosis was also unusual and very limited in extent. These findings accord with the potential for reversibility of heart failure seen in iron overload cardiomyopathy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00520559.

Hemosiderotic Juvenile Xanthogranuloma.

Juvenile xanthogranuloma is a non-Langerhans cell lesion mostly limited to the skin but occasionally presenting in extracutaneous locations or associated with systemic conditions. Lesions need to be distinguished mainly from dermatofibroma, xanthoma, Langerhans cell histiocytosis, or reticulohistiocytoma. Herein, we present a hemosiderotic variant of juvenile xanthogranuloma in a 12-year-old girl, which we have not found described in literature. The lesion presented at the back of the scalp as a slowly growing yellowish polypoid lesion showing occasional bleeding. The histopathological examination demonstrated a cellular infiltrate expanding the dermis, with a Grenz zone and with no remarkable changes in the overlying epidermis. The papule was made of mononucleated macrophages, many of which were xanthomatous. There were some Touton giant cells. The lesion was intermingled with a mild inflammatory infiltrate comprising lymphocytes, plasma cells, neutrophils, and some eosinophils. Many of the macrophages contained abundant cytoplasmic deposits of iron. The macrophages expressed CD68 and CD163, whereas they failed to express S100 protein, CD1a, and Langerin.

Auricular Hemosiderosis in a Diabetic Patient.

A 74-year-old Caucasian man with poorly controlled diabetes and hypertension was seen in the dermatology clinic for treatment of a nodular basal cell carcinoma on his right temple. He had poorly controlled diabetes for decades and had been insulin dependent for 20 to 25 years. He had not been on any anticoagulation therapy in the past or present and had no history of a hematologic disorder. He was retired and did woodworking as a hobby. During a routine presurgical head and neck skin examination, he was noted to have macular bluegray dyspigmentation of the central portion of the anterior portion of his ear lobes, bilaterally (Figure 1). He had first noticed this color change approximately 2 years ago and thought the pigmentation was darkening. It was not symptomatic. A punch biopsy was obtained.

AN ASSESSMENT OF THE FERROKINETIC INDICES IN RATS WITH TOXIC HEPATITIS UNDER THE CONDITIONS OF ALIMENTARY DEPRIVATION OF PROTEIN.

The ferrokinetic indices of blood serum of rats with acetaminophen-induced hepatitis under the conditions of alimentary deprivation of protein were assessed in the work. Research was conducted on 4 groups of animals: 1 - control; 2 - rats maintained on low-protein diet; 3 - rats with acute acetaminophen-induced hepatitis, maintained on full-value ration, 4 - rats with acute acetaminophen-induced hepatitis, maintained under the conditions of alimentary deprivation of protein. The serum iron content of and serum iron binding capacity were determined colorimetrically,% of the transferrin iron saturation - as a ratio of serum iron concentration to maximal iron binding capacity of serum transferrin. The presence of hemosiderin inclusions and the character of hemosiderosis were determined in the liver sections, stained by Perls method. Qualitative determination of C-reactive protein in blood serum was carried out by immunoenzymatic method. It is shown, that in protein-deficiency rats any significant changes of iron metabolism indices and hemosiderin accumu- lation weren't observed. At the same time in rats with acetaminophen-induced hepatitis the 5-fold increase of the serum iron content against the background non-significant increase of serum iron binding capacity and the 2-fold increase of the transferrin iron saturation is established. Simultaneously in the hepatocytes and reticuloendothelial system cells the accumulation of hemosiderin in the low dispersion form is observed, equating the second degree of hemosiderosis on the background emerging of C-reactive protein in serum. In protein-deficiency rats with toxic liver injury an abrupt increase of serum iron against the background reduction of the total serum iron binding capacity and maximal saturation of transferrin by iron ions is observed. It is established, that for animals from current group the third degree of mixed type hemosiderosis and the intensification of the inflammatory reaction in liver is characterstic. Conclusion was made, that alimentary deprivation of protein under the conditions of toxic liver injury is the critical factor for structural-functional state of liver, being accompanied by the iron metabolism disturbances, development of hemosiderosis and intensification of the inflammatory reaction in liver. Research results may be used for the biochemical rationale of the therapeutic approaches for the elimination and correction of the toxic liver injury consequences.

Thalassemia major between liver and heart: Where we are now.

The aim of the study was to assess the current state in terms of liver and heart iron overload as well as of liver and heart related morbidity and mortality in a large cohort of thalassemia patients. Myocardial iron loading was present in 28.9% patients, which was severe in 3.2%. Liver iron was normal in 9.3% and severe in 15%. The rate of cardiac deaths started to decrease between 2000 and 2003 and dropped significantly afterwards. The prescription of combination therapy soon after the hospital admission for decompensated heart failure was associated with a decrease in the short-term mortality. In 111 adult patients who underwent liver elastometry, 14 HCVRNA positive subjects and 2 HCVRNA negative, had stiffness values suggestive of cirrhosis. No cases of hepatocarcinoma were reported. Liver "iron free foci" occurred in a HCV negative patient and the occurrence of a malignant epithelioid hemangioendothelioma led to liver transplantation in another. The study suggests that a subset of patients continues to develop progressive hemosiderosis that may lead to cardiac disease and death. Beyond its key role in preventing myocardial iron overload, liver iron chelation is essential for hampering the onset of hepatic tumors, which may not be limited to hepatocarcinoma.

Islet inflammation, hemosiderosis, and fibrosis in intrauterine growth-restricted and high fat-fed Sprague-Dawley rats.

Prenatal and postnatal factors such as intrauterine growth restriction (IUGR) and high-fat (HF) diet contribute to type 2 diabetes. Our aim was to determine whether IUGR and HF diets interact in type 2 diabetes pathogenesis, with particular attention focused on pancreatic islet morphology including assessment for inflammation. A surgical model of IUGR (bilateral uterine artery ligation) in Sprague-Dawley rats with sham controls was used. Pups were fed either HF or chow diets after weaning. Serial measures of body weight and glucose tolerance were performed. At 25 weeks of age, rat pancreases were harvested for histologic assessment. The birth weight of IUGR pups was 13% lower than that of sham pups. HF diet caused excess weight gain, dyslipidemia, hyperinsulinemia, and mild glucose intolerance, however, this was not aggravated further by IUGR. Markedly abnormal islet morphology was evident in 0 of 6 sham-chow, 5 of 8 sham-HF, 4 of 8 IUGR-chow, and 8 of 9 IUGR-HF rats (chi-square, P = 0.007). Abnormal islets were characterized by larger size, irregular shape, inflammation with CD68-positive cells, marked fibrosis, and hemosiderosis. ß-Cell mass was not altered by IUGR. In conclusion, HF and IUGR independently contribute to islet injury characterized by inflammation, hemosiderosis, and fibrosis. This suggests that both HF and IUGR can induce islet injury via converging pathways. The potential pathogenic or permissive role of iron in this process of islet inflammation warrants further investigation.

Iron oxides in human spleen.

Iron is an essential element for fundamental cell functions and a catalyst for chemical reactions. Three samples extracted from the human spleen were investigated by scanning (SEM) and transmission electron microscopy (TEM), Mössbauer spectrometry (MS), and SQUID magnetometry. The sample with diagnosis of hemosiderosis (H) differs from that referring to hereditary spherocytosis and the reference sample. SEM reveals iron-rich micrometer-sized aggregate of various structures-tiny fibrils in hereditary spherocytosis sample and no fibrils in hemochromatosis. Hematite and magnetite particles from 2 to 6 µm in TEM with diffraction in all samples were shown. The SQUID magnetometry shows different amount of diamagnetic, paramagnetic and ferrimagnetic structures in the tissues. The MS results indicate contribution of ferromagnetically split sextets for all investigated samples. Their occurrence indicates that at least part of the sample is magnetically ordered below the critical temperature. The iron accumulation process is different in hereditary spherocytosis and hemosiderosis. This fact may be the reason of different iron crystallization.

Frequency and appearance of hemosiderin depositions after aneurysmal subarachnoid hemorrhage treated by endovascular therapy.

INTRODUCTION: It is still unclear how often subarachnoid hemorrhage (SAH) leads to chronic hemosiderin depositions. In this study, we aimed to determine the frequency of chronic hemosiderin depositions after aneurysmal SAH in patients who did not undergo surgery. Furthermore, we analyzed typical MRI patterns of chronic SAH and sought to obtain information on the temporal course of MRI signal changes. METHODS: We retrospectively analyzed 90 patients who had undergone endovascular treatment for acute aneurysmal SAH. In all patients, initial CT studies and at least one T2*-weighted MRI obtained 6 months or later after SAH were analyzed for the presence and anatomical distribution of SAH or chronic hemosiderin depositions. In total, 185 T2*-weighted MRI studies obtained between 2 days and 148 months after SAH were evaluated (mean follow-up 30.2 months). RESULTS: On MRI studies obtained later than 6 months after SAH, subpial hemosiderin depositions were found in 50 patients (55.5%). Most frequent localizations were the parenchyma adjacent to the frontal and parietal sulci and the insular cisterns. While the appearance of hemosiderin depositions was dynamic within the first 3 months, no changes were found during subsequent follow-up. MR signal changes were not only conclusive with subarachnoid hemosiderin depositions but in many cases also resembled those that have been associated with cortical hemosiderosis. CONCLUSIONS: T2*-weighted MRI is an effective means of diagnosing prior SAH. Our study suggests that chronic hemosiderin depositions can be found in a considerable number of patients after a single event of subarachnoid hemorrhage.

Radiological imaging features and clinicopathological correlation of hemosiderotic fibrolipomatous tumor: experience in a single tertiary cancer center.

OBJECTIVE: To determine the imaging features of hemosiderotic fibrolipomatous tumor (HFLT), which has a propensity towards local recurrence and the potential to transform into myxoinflammatory fibroblastic sarcoma (MIFS). MATERIALS AND METHODS: The study included 8 patients with a diagnosis of HFLT and imaging at a tertiary cancer center. Imaging studies included radiographs (n = 2), ultrasound (n =  3), and MRI (n = 16). Imaging features were evaluated including location, calcification, sonographic echogenicity, vascular flow, size, border, signal characteristics, contrast enhancement, and blooming on MRI. RESULTS: The HFLT was located in the ankle/foot in 4 out of 8 and was subcutaneous in 8 out of 8, ranging in size from 2 to 18 cm. Histology at initial diagnosis was HFLT in 5 out of 8 and HFLT with MIFS in 3 out of 8. None was calcified on radiography. On ultrasound 2 out of 3 were heterogeneously echogenic with ≥10 foci of vascular flow. Two out of 8 patients had MRI only at local recurrence. The tumor border was infiltrative in 4 out of 6 at initial diagnosis and in 2 patients with MRI at recurrence only. Fat and septae were present in 7 out of 8 at initial diagnosis and at recurrence. Signal intensity was iso-/hypointense to muscle on T1-weighted sequences in more than two thirds of the tumor in 4 out of 7 and hyperintense to muscle in at least one third of the tumor on fluid-sensitive sequences in 6 out of 8. Contrast enhancement was heterogeneous in 7 out of 7; blooming in two thirds of the tumor on gradient-echo sequence MRI indicated hemorrhage. CONCLUSION: The HFLT commonly presents as a mass with an infiltrative border, interspersed fat and septations at initial diagnosis and local recurrence on MRI regardless of histology of HFLT alone or with MIFS. Hemosiderin deposits may be detected as blooming on gradient-echo sequences.

A RETROSPECTIVE STUDY OF PATHOLOGIC FINDINGS IN CAPTIVE ROCK HYRAX (PROCAVIA CAPENSIS) IN THE UNITED STATES.

A retrospective examination of gross and histologic reports was performed to find common lesions in young and adult captive rock hyrax ( Procavia capensis ) from multiple zoo populations. One hundred and thirty-seven reports were analyzed from specimens that were submitted to Northwest ZooPath from 1997 to 2013. Histologic findings from necropsy and biopsy reports and causes of mortality only from necropsy reports were compiled to determine the most common findings. Within the study population, 41 (30%) were male, 62 (45%) were female, and the remainder (34, 25%) were of undetermined sex. Of the 111 necropsies, 87 (78%) died naturally, and 24 (22%) were euthanatized. There were 26 (19%) biopsies with no known status of the animal. The most frequent causes of death or reason for euthanasia were bacterial septicemia (n = 29, 21%) and degenerative cardiomyopathy (n = 29, 21%). The other most prevalent lesions were hemosiderosis (n = 55, 40%), pancreatic islet and interstitial fibrosis (n = 36, 26%), pneumonia of undetermined cause (n = 26, 19%), enteritis/colitis (n = 24, 18%), and renal tubular necrosis (n = 20, 15%). In many animals of this study population (n = 115, 84%), multiple lesions affecting multiple organs were found.

Donor hemosiderosis does not affect liver function and regeneration in the setting of living donor liver transplantation.

Living donor liver transplantation (LDLT) demands a careful assessment of abnormal findings discovered during the evaluation process to determine if there will be any potential risks to the donor or recipient. Varying degrees of elevated hepatic iron levels are not uncommonly seen in otherwise healthy individuals. We questioned whether mild expression of hemosiderin deposition presents a safety concern when considering outcomes of living donation for both the donor and the recipient. We report on three LDLT patients who were found to have low- to moderate-grade hemosiderin deposition on liver biopsy. All other aspects of their evaluation proved satisfactory, and the decision was made to proceed with donation. There were no significant complications in the donors, and all demonstrated complete normalization of liver function postoperatively, with appropriate parenchymal regeneration. The recipients also had unremarkable postoperative recovery. We conclude that these individuals can be considered as potential donors after careful evaluation.

Biopsy-based calibration of T2* magnetic resonance for estimation of liver iron concentration and comparison with R2 Ferriscan.

BACKGROUND: There is a need to standardise non-invasive measurements of liver iron concentrations (LIC) so clear inferences can be drawn about body iron levels that are associated with hepatic and extra-hepatic complications of iron overload. Since the first demonstration of an inverse relationship between biopsy LIC and liver magnetic resonance (MR) using a proof-of-concept T2* sequence, MR technology has advanced dramatically with a shorter minimum echo-time, closer inter-echo spacing and constant repetition time. These important advances allow more accurate calculation of liver T2* especially in patients with high LIC. METHODS: Here, we used an optimised liver T2* sequence calibrated against 50 liver biopsy samples on 25 patients with transfusional haemosiderosis using ordinary least squares linear regression, and assessed the method reproducibility in 96 scans over an LIC range up to 42 mg/g dry weight (dw) using Bland-Altman plots. Using mixed model linear regression we compared the new T2*-LIC with R2-LIC (Ferriscan) on 92 scans in 54 patients with transfusional haemosiderosis and examined method agreement using Bland-Altman approach. RESULTS: Strong linear correlation between ln(T2*) and ln(LIC) led to the calibration equation LIC = 31.94(T2*)-1.014. This yielded LIC values approximately 2.2 times higher than the proof-of-concept T2* method. Comparing this new T2*-LIC with the R2-LIC (Ferriscan) technique in 92 scans, we observed a close relationship between the two methods for values up to 10 mg/g dw, however the method agreement was poor. CONCLUSIONS: New calibration of T2* against liver biopsy estimates LIC in a reproducible way, correcting the proof-of-concept calibration by 2.2 times. Due to poor agreement, both methods should be used separately to diagnose or rule out liver iron overload in patients with increased ferritin.

Calibration of myocardial T2 and T1 against iron concentration.

BACKGROUND: The assessment of myocardial iron using T2* cardiovascular magnetic resonance (CMR) has been validated and calibrated, and is in clinical use. However, there is very limited data assessing the relaxation parameters T1 and T2 for measurement of human myocardial iron. METHODS: Twelve hearts were examined from transfusion-dependent patients: 11 with end-stage heart failure, either following death (n=7) or cardiac transplantation (n=4), and 1 heart from a patient who died from a stroke with no cardiac iron loading. Ex-vivo R1 and R2 measurements (R1=1/T1 and R2=1/T2) at 1.5 Tesla were compared with myocardial iron concentration measured using inductively coupled plasma atomic emission spectroscopy. RESULTS: From a single myocardial slice in formalin which was repeatedly examined, a modest decrease in T2 was observed with time, from mean (± SD) 23.7 ± 0.93 ms at baseline (13 days after death and formalin fixation) to 18.5 ± 1.41 ms at day 566 (p<0.001). Raw T2 values were therefore adjusted to correct for this fall over time. Myocardial R2 was correlated with iron concentration [Fe] (R2 0.566, p<0.001), but the correlation was stronger between LnR2 and Ln[Fe] (R2 0.790, p<0.001). The relation was [Fe] = 5081•(T2)-2.22 between T2 (ms) and myocardial iron (mg/g dry weight). Analysis of T1 proved challenging with a dichotomous distribution of T1, with very short T1 (mean 72.3 ± 25.8 ms) that was independent of iron concentration in all hearts stored in formalin for greater than 12 months. In the remaining hearts stored for <10 weeks prior to scanning, LnR1 and iron concentration were correlated but with marked scatter (R2 0.517, p<0.001). A linear relationship was present between T1 and T2 in the hearts stored for a short period (R2 0.657, p<0.001). CONCLUSION: Myocardial T2 correlates well with myocardial iron concentration, which raises the possibility that T2 may provide additive information to T2* for patients with myocardial siderosis. However, ex-vivo T1 measurements are less reliable due to the severe chemical effects of formalin on T1 shortening, and therefore T1 calibration may only be practical from in-vivo human studies.