Authors:
O. Papakonstantinou1, Z. Spyridaki2, T. Maris2, V. Ladis1, S. Kostaridou1, S. Karampekios2, N. Gourtsoyiannis3; 1Athens/GR, 2Iraklion/GR, 3Heraklion/GR
DOI:
10.1594/ECR03/C-0525
Methods and Materials
PatientsThe MR imaging studies of 54 consecutive patients with beta-thalassemia major (aged 14-41 yrs, mean 266.3) were retrospectively reviewed. All patients received systematic red blood cell transfusions and subcutaneous chelation with desferroxamine. Thirty-seven of the 54 patients had post-transfusion chronic hepatitis, 33 of them chronic hepatitis C [HCV(+)] and 4 chronic hepatitis B [HBc(+)] respectively. Total iron burden was assessed in all patients by means of serum ferritin levels, whereas liver iron concentration was determined in liver biopsy specimens, in 14 patients, with atomic absorption spectrophotometry. MR imaging: Imaging techniqueAll MR imaging examinations were performed in a 3-year period, on a 0.5 T MR imaging system (Magnetom Vision, Siemens). Body coil was used for excitation and signal detection. The following sequences were applied: gradient-echo (GRE) : T1 (180/4.6/90), proton density (160/4/20), double-echo opposed phase (SINOP) (160/2.7-5.3, 20), Turbo spin-echo (TSE) : T1(TR/TE/FA) (600/6, echo train length:3 ), T2 (TR/TE/FA) (6000/90, echo train lenth: 64). Section thickness was 10 mm, intersection gap 2 mm, matrix was 256*192, FOV 400 mm. Sequence selection had been decided on the basis of the highest correlations between L/M and liver iron concentration. Image analysisSignal intensities were measured at five regions of interest (ROIs) on liver, away from vascular structures, each one encompassing at least 100 pixels. The signal intensity of the right paraspinous muscle was also measured. Subsequently, the signal intensity ratios of each ROI and the mean signal intensity ratios of liver to paraspinous muscle (L/M) were calculated Evaluation of abdominal lymphadenopathyAbdominal lymphadenopathy was evaluated by two experienced abdominal radiologists by consensus and without knowing the clinical and laboratory data. The lymph nodes on MR images were categorized in five groups: periportal (at the hilum, anterior to portal vein and to the right of the proper hepatic artery), peripancreatic (in close contact with the anterior aspect of the pancreas, mainly the body), portocaval space, celiac (in front of the hepatic artery and adjacent to its origin from the celiac axis), and paraortic. All nodes with a short axis diameter larger than 5 mm were measured, their location, number and signal intensity were recorded. For each patient, the signal intensity ratio of the largest node over the signal intensity of the paraspinous muscle (N/M) was estimated for all MR imaging sequences. StatisticsX2 test was used to verify the relation between lymphadenopathy and post-transfusion hepatitis, whereas differences in L/M values between patients with and without lymphadenopathy were assessed by means of students t-test.