Diagnosis and quantification of the iron overload through Magnetic resonance. / Diagnóstico y cuantificación de la sobrecarga férrica mediante resonancia magnética.

There are different magnetic resonance techniques and models to quantify liver iron concentration. T2 relaxometry methods evaluate the iron concentration in the myocardium, and they are able to discriminate all the levels of iron overload in the liver. Signal intensity ratio methods saturate with high levels of liver overload and can not assess iron concentration in the myocardium but they are more accessible and are very standardized. This article reviews, in different clinical scenarios, when Magnetic Resonance must be used to assess iron overload in the liver and myocardium and analyzes the current challenges to optimize the aplication of the technique and to be it included in the clinical guidelines.

Medición del T2* hepático y cardíaco en la hemocromatosis secundaria / Liver and heart T2* measurement in secondary haemochromatosis

Objetivo. Valorar la sobrecarga férrica mediante el cálculo del valor T2* en el hígado y el miocardio en los pacientes con hemocromatosis secundaria. Evaluar la correlación de los valores obtenidos con los niveles de ferritina en sangre y la concentración de hierro hepático (CHH) calculada mediante resonancia magnética (RM), y la correlación de los valores T2* entre sí. Material y métodos. Se incluyeron 16 pacientes (13 varones y 3 mujeres), evaluados entre los años 2008 y 2009, con una edad media de 61 años. Quince eran pacientes politransfundidos y uno estaba diagnosticado de anemia sideroblástica hereditaria. Se estudió la ferritina en sangre, la CHH por RM, la función cardíaca mediante RM y el valor T2* mediante secuencias multieco en el hígado (TR/TE1/ΔTE/n°ecos/α: 21/1,18/1.0/20/35°) y el miocardio (26/1,04/0.8/30/60°). Se realizó el análisis de correlación-regresión de los valores T2* cardíaco y hepático con los valores de ferritina y CHH, y entre sí. Resultados. Trece pacientes mostraron valores de ferritina superiores a 1.000 ng/ml (mediana/mínimo/máximo: 1.762/294/3.785 ng/ml). Trece pacientes presentaron CHH elevada, mayor de 80 μmol/g (mediana/mínimo/máximo: 125,4/41,2/241,5 μmol/g). En todos los casos la función cardíaca estaba preservada. En 15 pacientes el valor T2* hepático fue menor de 6,3 ms. Solo en un caso, el valor T2*miocárdico fue menor de 20 ms. Se observó una alta correlación para los valores T2*hepático/CHH (r: -0,912). La correlación fue estadísticamente significativa para T2* hepático/ferritina (r: -0,541). La correlación T2*miocárdico/ferritina, T2*miocárdico/CHH y T2*miocárdico/T2*hepático no fue estadísticamente significativa. Conclusión. Los valores T2* hepático muestran una alta correlación con la CHH y una correlación estadísticamente significativa con la ferritina. No se observó correlación entre los valores T2* miocárdico y la ferritina en sangre, la CHH, ni con el valor T2* hepático (AU)

Objective: To determine whether there is iron overload by calculating the T2* value in the liver and myocardium in patients with secondary haemochromatosis. To analyse the correlation of the values obtained with the iron levels in blood, with the liver iron concentration (LIC) calculated using magnetic resonance (MR) imaging, and the correlation between them. Material and methods: A total of 16 patients (13 males, 3 females), with a mean age of 61 years, were included and evaluated in the years 2008 and 2009. Fifteen of them had received multiple transfusions, and one was diagnosed with hereditary sideroblastic anaemia. The measurements included, blood ferritin, LIC by MRI, cardiac function using MRI and the T2* value by means of multi-echo sequences in the liver (TR/TE1/ TE/No of echos/ : 21/1,18/1.0/20/35◦) and myocardium (26/1.04/0.8/30/60◦). A correlation-regression analysis was performed by comparing the cardiac and liver T2* values with the ferritin, LIC and between each of them. Results: A total of 13 patients had ferritin values greater than 1000 ng/ml (median/minimum/maximum: 1762/294/3785 ng/ml). An increased LIC greater than 80 mol/g (median/minimum/maximum: 125.4/41.2/241.5 mol/g) was observed in 13 patients. In all cases cardiac function was conserved, and in 15 cases the liver T2* value was less than 6.3 ms. The myocardium T2* value was less than 20 ms. in only one case. A high correlation was observed between the liver T2* values and the LIC (r: -0.912). The correlation was statistically significant between the liver T2* value and ferritin (r: -0.541). The correlations between myocardium T2* and ferritin, myocardium T2* and LIC, and myocardium T2* and liver T2* were not statistically significant. Conclusions: The liver T2* showed a high correlation with LIC and a statistically significant correlation with ferritin. No association was observed between the myocardium T2* values and ferritin in blood, the LIC or the liver T2* value (AU)

[Liver and heart T2* measurement in secondary haemochromatosis]. / Medición del T2* hepático y cardíaco en la hemocromatosis secundaria.

OBJECTIVE: To determine whether there is iron overload by calculating the T2* value in the liver and myocardium in patients with secondary haemochromatosis. To analyse the correlation of the values obtained with the iron levels in blood, with the liver iron concentration (LIC) calculated using magnetic resonance (MR) imaging, and the correlation between them. MATERIAL AND METHODS: A total of 16 patients (13 males, 3 females), with a mean age of 61 years, were included and evaluated in the years 2008 and 2009. Fifteen of them had received multiple transfusions, and one was diagnosed with hereditary sideroblastic anaemia. The measurements included, blood ferritin, LIC by MRI, cardiac function using MRI and the T2* value by means of multi-echo sequences in the liver (TR/TE1/ΔTE/No of echos/α: 21/1,18/1.0/20/35°) and myocardium (26/1.04/0.8/30/60°). A correlation-regression analysis was performed by comparing the cardiac and liver T2* values with the ferritin, LIC and between each of them. RESULTS: A total of 13 patients had ferritin values greater than 1000ng/ml (median/minimum/maximum: 1762/294/3785ng/ml). An increased LIC greater than 80µmol/g (median/minimum/maximum: 125.4/41.2/241.5µmol/g) was observed in 13 patients. In all cases cardiac function was conserved, and in 15 cases the liver T2* value was less than 6.3ms. The myocardium T2* value was less than 20ms. in only one case. A high correlation was observed between the liver T2* values and the LIC (r:-0.912). The correlation was statistically significant between the liver T2* value and ferritin (r:-0.541). The correlations between myocardium T2* and ferritin, myocardium T2* and LIC, and myocardium T2* and liver T2* were not statistically significant. CONCLUSIONS: The liver T2* showed a high correlation with LIC and a statistically significant correlation with ferritin. No association was observed between the myocardium T2* values and ferritin in blood, the LIC or the liver T2* value.

[Magnetic resonance imaging and lung perfusion scintigraphy in tetralogy of Fallot following surgery]. / Resonancia magnética y gammagrafía de perfusión pulmonar en casos de tetralogía de Fallot operados.

OBJECTIVE: To evaluate pulmonary arteries in patients with tetralogy of Fallot following surgery with quantified lung perfusion scintigraphy and magnetic resonance imaging. MATERIAL AND METHODS: From January 1985 to December 1999, 47 patients who underwent surgery between 1985 and 1999 were studied. To obtain values of normality, 45 infants with no pulmonary artery disease were assessed with lung perfusion scintigraphy (right lung flow: 54-61%, left lung flow: 38.7-46%) and magnetic resonance imaging axial view (right/left pulmonary artery branch diameter ratio: 1-1.1). Patients with stenosis underwent catheterization. RESULTS: Group 1: 27 patients with normal parameters. Group 2: nine patients with left pulmonary branch stenosis and irregularities in all parameters; left/right branch diameter ratio 0.51 and left lung perfusion 26.3 +/- 7.9%, r correlation ratio 65%, p < 0.005, left branch pressure gradient 34.4 +/- 17.9 mm Hg, rate-gradient r 89%, p < 0.001. Group 3: five patients with right pulmonary branch stenosis and irregularities in all parameters; right/left branch diameter ratio 0.52, reduced right lung perfusion 32 +/- 11%, with a stenotic branch gradient of 40 +/- 19 mm Hg., rate/gradient ratio r 72%, p < 0.005; gradient/perfusion ratio r 82%, p < 0.003. Group 4: Six patients with bilateral stenosis, reduced diameter in the stenotic area with normal perfusion in both lungs and bilateral gradient. Eighteen patients with stenosis underwent re-operation, with favorable outcome in 14. CONCLUSION: Magnetic resonance imaging and quantified lung perfusion scintigraphy provide useful information in the follow-up of tetralogy of Fallot.

Resonancia magnética y gammagrafía de perfusión pulmonar en casos de tetralogía de Fallot operados / Magnetic resonance imaging and lung perfusion scintigraphy in the tetralogy of fallot following surgery

Objetivo: Estudio de las ramas pulmonares de los pacientes intervenidos de tetralogía de Fallot con gammagrafía de perfusión cuantificada y resonancia magnética (RM).Material y métodos Desde enero de 1995 a diciembre de 1999 se estudiaron 47 pacientes intervenidos durante el período 1985-1999. Para obtener valores de normalidad, se estudiaron 45 jóvenes sin enfermedad pulmonar con gammagrafía (flujo pulmón derecho, 54-61 por ciento; flujo pulmón izquierdo, 38,7-46 por ciento) y RM en proyección axial (índice diámetro rama derecha/diámetro rama izquierda, 1-1,1). Los pacientes con estenosis fueron cateterizados. Resultados: Grupo 1: 27 pacientes con parámetros normales. Grupo 2: pacientes con estenosis de la rama pulmonar izquierda (9 casos con todos los parámetros alterados). Índice diámetro rama izquierda/rama derecha, 0,51, y perfusión pulmón izquierdo, 26,3+/-7,9 por ciento; coeficiente correlación r 65 por ciento; p < 0,005. Con un gradiente de presión en la rama izquierda de 34,4+/-17,9 mmHg índice/gradiente r 89 por ciento; p < 0,001. Grupo 3: 5 pacientes con estenosis rama pulmonar derecha con todos los parámetros alterados. Índice diámetro rama derecha/diámetro rama izquierda 0,52, disminución de la perfusión del pulmón derecho 32+/-11 por ciento con gradiente en esta rama de 40+/-19 mmHg con coeficiente índice/gradiente r 72 por ciento; p < 0,005; gradiente/perfusión r 82 por ciento; p < 0,003. Grupo 4: 6 pacientes con estenosis bilateral. Perfusión normal con diámetro reducido en la zona de estenosis. Dieciocho pacientes con obstrucción fueron reintervenidos y reevaluados con buenos resultados en 14 pacientes. Conclusión: La RM y la gammagrafía de perfusión cuantificada aportan información en el seguimiento de la tetralogía de Fallot (AU)