CMR T2 Research Articles

Cardiac involvement in sickle β-thalassemia

Cardiovascular involvement is a leading cause of mortality and morbidity in patients with inherited hemoglobinopathies, but it has not been adequately assessed in sickle beta-thalassemia. We evaluated 115 sickle beta-thalassemia patients, aged 34 +/- 14 years, along with 50 healthy controls, by resting echocardiography. Patients with systolic left ventricular (LV) dysfunction or severe pulmonary hypertension (PHT) also underwent left and right cardiac catheterization and cardiac magnetic resonance imaging (CMR). Left and right chamber dimensions, LV mass, and cardiac index were significantly higher in patients compared to controls (p < 0.001 in most cases). Three patients (2.9%) had reduced LV ejection fraction (<55%); mean LV ejection fraction was significantly lower in patients (p < 0.001). Left and right ventricular systolic tissue Doppler indices and LV diastolic tissue Doppler indices were also impaired in patients. All three patients with systolic LV dysfunction had normal coronary arteries and mild myocardial iron load (CMR T2* values, 18-25 ms). Systolic pulmonary artery pressure was significantly higher in patients compared to controls (p = 0.002); PHT was present in 28 patients (27%), while severe PHT in three (2.9%). In three patients with severe PHT, only one had impaired LV ejection fraction and increased pulmonary wedge pressure. Overall, three patients (2.9%) had a history of heart failure, two with systolic LV dysfunction, and one with severe PHT. Cardiac involvement in sickle beta-thalassemia concerns biventricular dilatation and dysfunction along with PHT, leading to congestive heart failure.

Gender Differences in Iron Overload and Left Ventricular Function in a Cohort of Thalassemia Major Patients: A Prospective Study of a Single Italian Center Using Cardiovascular Magnetic Resonance.

Introduction: cardiac failure due to secondary iron overload remains the main cause of death in patients with b-Thalassemia Major (TM). Cardiovascular Magnetic Resonance Imaging (CMR) T2* technique is a new tool to assess myocardial iron concentration that allows to tailor the optimal iron chelation treatment for each patient.Aim of the study: to assess left ventricular function and myocardial iron overload in a cohort of TM patients, cared at Hereditary Anemia Center in Milan, Italy.Methods and Results: In 91 TM patients (33 males/58 females, mean age 32 ± 6 yrs) myocardial iron loading was assessed with the use of CMR T2* measurements (CMR Tools, Cardiovascular Imaging Solutions, London, UK). Left ventricular ejection fraction (LVEF) was also assessed with CMR. In the overall group hemoglobin levels were 9.0 ± 1.0 g/dl; the mean serum ferritin levels and iron intake during the six months before CMR evaluation were 1507 ± 1884 ng/ml and 0.34 ± 0.08 mg/kg/die respectively. T2* was significantly different between females and males (24 ± 11 and 32 ± 12 ms, respectively; p < 0.0001), with significant differences in diabetes mellitus prevalence (17% vs 8%, p<0.01) but not in age, serum ferritin, iron intake and hemoglobin levels (Table 1). Seven (7.6%) asymptomatic females showed a severe cardiac iron overload (T2* ≤ 10 ms), 9 patients (9.9%) moderate (T2* between 10.1 and 14 ms), 15 patients (16.4%) mild cardiac iron overload (T2* between 14.1 and 20 ms) and 60 patients (65.9%) had normal T2* (> 20 ms). LVEF was significantly different between females and males (35% vs 57%, p<0.001) with evidence of a significant relationship between iron overload severity and LVEF impairment (r=0.92).Conclusions: CMR cardiac function and T2* assessment allow to detect pre-symptomatic cardiac iron overload. Females are more at risk for severe iron overload and left ventricular impairment. The prevalence of diabetes mellitus and compliance to chelation therapy could be relevant in explaining the gender differences.Clinical parameters and T2* values in men and women with thalassemia majorMenpWomenNumber of patients (n. of pts)33-58Age ± SD (years)33 ± 6ns32 ± 6Hemoglobin levels ± SD (g/dl)9.0 ± 1.7ns9.0 ± 0.8Ferritin levels ± SD (ng/ml)964 ± 891ns1821 ± 2216Iron intake ± SD (mg/Kg/die)0.30 ± 0.07ns0.36 ± 0.09Mean T2* value ± SD (ms)32 ± 12<0.000124 ± 11T2*< 10 ms (n. of pts)0-7T2* between 10.1 and 14 ms (n. of pts)1-8T2* between 14.1 and 20 ms (n. of pts)7-8T2* > 20 ms (n. of pts)25-35T2*< 10 ms (n. of pts) plus LVEF≤ 57 %0/0 (0%)-6/7 (85.7%)T2* between 10.1 and 14 ms (n. of pts) plus LVEF≤ 57 %1/1 (100%)-3/8 (37.5%)T2* between 14.1 and 20 ms (n. of pts) plus LVEF≤ 57 %3/7 (42.8%)-1/8 (12.5%)T2* > 20 ms (n. of pts) plus LVEF≤ 57 %7/25 (28%)-5/35 (14.3%)SD: standard deviation

THE COMBINED APPLICATION AND UTILISATION OF CMR™ AND FMI™ WIRELINE TECHNOLOGY IN WONNICH-I

Wonnich, a new gas and oil discovery was drilled in July 1995 within exploration permit TP/8 Part 1 in the Barrow Sub-3asin. The well was logged using emerging wireline technology which resulted m significant im­provements in understanding the quality of reservoir rocks, their genesis and post depositiunal alterations. Both the Combinable Magnetic Resonance Imaging Tool (CMR™) and the Formation Micro-Imager (FMI™) data were acquired in the 216 mm hole section of the well. The interval between 2.575 and 2,525 m. which forms the basis of this technology review, comprises an aquifer sandstone which was logged with the CMR tool to inves­tigate the pore size and distribution and to provide a comparison between the CMR porosity and standard porosity derivations. The CMR data presented in this paper was p-ocessed by Schlumberger using the stan­dard sandstone settings. The high resolution, density derived porosity and the CMR porosity showed good agreement in both magnitude and vertical resolution. The aquifer sandstones reached a maximum of 18 per cent porosity with a CMR permeability maximum of 400md between 2,544-2,551 m. The T2 relaxation times distribution in sands, occurs between 33 and 250 ms with the peak and mean coinciding at 100ms. Several shale intervals show T2 attenuation due to hole washout. Utilising both the FMI azimuthal images and the CMR permeability curve it was established that some of the permeability barriers shown by the CMR and 'regular' open hole logs are in fact nodular formation components, rather than beds. These would thus not impact fluid flow and completion design. Further image analysis within the aquifer sands shows that the palaeocurrent direction is northwest, with a southeasterly sediment provenance. The larger scale process signatures within the lower sand are replaced by friction dominated and low energy pro­cesses towards the upper portion of the sand. This fining upwards profile is reflected not only in the GR logs but also in the pore size reductions shown by the CMR T2 relaxation profiles extending the application of these technologies to depositional environment analysis and grain size distribution. Post depositional influences in­clude siderite and clay diagenesis and fracturing associ­ated with aquifer seals.