Article Figures & Data
Figures
- Fig 1.
Left to right: Magnitude image, filtered phase image, and susceptibility image for (A) a healthy volunteer and (B) patient with thalassemia. For the patient with thalassemia, overloading of iron content in the choroid plexus can be observed as low signal intensity on the magnitude image and filtered phase image and high signal intensity in the susceptibility image (arrows).
- Fig 2.
Mean susceptibility map on (A) axial, (B) coronal, and (C) sagittal plane and (D–G) placement of ROIs on the mean susceptibility map, including the caudate nucleus (CN), putamen (PT), globus pallidus (GP), red nucleus (RN), substantia nigra (SN), dentate nucleus (DN) and choroid plexus (CP).
Tables
- Table 1:
Results of linear regression of the susceptibility value on the control group with age and sex as independent variables
ROI Intercept /10−2 ppm Age /10−3 ppm Sex /10−3 ppm P Value of Age P Value of Sex PT 0.45 0.51 1.15 .002 .346 GP 7.22 0.18 8.26 .729 .057 CN 1.55 0.18 0.30 .338 .837 DN 1.60 1.10 8.68 .017 .018 SN 4.35 1.22 −3.49 .044 .455 RN 1.26 1.72 1.07 .014 .841 CP 3.83 −0.341 9.75 .763 .284 Note:—Significant positive age effect on susceptibility value was found in PT, DN, SN, and RN, suggesting higher level of iron concentration with increasing age. In the DN, significantly higher susceptibility value was found in women compared with men after controlling for the effect of age. In other regions except for the SN, the susceptibility value was also higher in women, though these differences were not statistically significant. These findings suggest that in the majority of brain regions, iron concentration increases with age and is higher among women.
SD indicates standard deviation; PT, putamen; GP, globus pallidus; CN, caudate nucleus; DN, dentate nucleus; SN, substantia nigra; RN, red nucleus; CP, choroid plexus.
- Table 2:
Mean (standard deviation) of susceptibility values of different ROIs between healthy control subjects and patients with thalassemia and P values for group effect with the use of the general linear model after controlling for effects of age and sex
PT GP CN DN SN RN CP Control subjects (10−2 ppm) 1.82 (0.40) 8.23 (1.24) 2.04 (0.41) 4.94 (1.19) 7.42 (1.35) 5.75 (1.63) 3.00 (0.63) Patients (10−2 ppm) 1.91 (0.63) 6.58 (2.23) 2.04 (0.62) 4.55 (1.81) 6.33 (1.37) 6.67 (2.52) 7.17 (4.55) P value .248 <.001 .842 .246 .003 .021 <.001 Note:—Significantly lower susceptibility value was found in patients with thalassemia compared with healthy control subjects in GP and SN; significantly higher susceptibility value was found in patients with thalassemia in RN and CP.
PT indicates putamen; GP, globus pallidus; CN, caudate nucleus; DN, dentate nucleus; SN, substantia nigra; RN, red nucleus; CP, choroid plexus.
- Table 3:
Number of patients with thalassemia with iron overloading or underloading in each ROI
PT GP CN DN SN RN CP Iron overload 1 0 2 1 0 3 20 Iron underload 0 11 0 2 1 0 0 Note:—PT indicates putamen; GP, globus pallidus; CN, caudate nucleus; DN, dentate nucleus; SN, substantia nigra; RN, red nucleus; CP, choroid plexus.
Mean (SD) /10−2 ppm P Value DFO L1 DFO+L1 Exjade PT 1.82 (0.69) 2.09 (0.50) 1.81 (0.59) 2.07 (0.85) .201 GP 7.64 (2.07) 6.69 (3.50) 5.62 (1.73) 7.06 (1.06) .296 CN 2.37 (0.60) 1.66 (0.49) 1.98 (0.54) 2.09 (0.80) .232 DN 4.95 (1.53) 3.50 (1.57) 4.44 (2.08) 5.44 (1.55) .064 SN 6.87 (1.77) 5.89 (1.61) 6.28 (1.15) 6.08 (0.86) .573 RN 6.01 (3.23) 7.26 (1.85) 6.86 (1.90) 6.55 (3.68) .801 CP 7.38 (4.28) 7.03 (3.63) 7.47 (6.09) 6.24 (1.75) .955 Note:—No significant difference was found in susceptibility values between patients receiving different chelation agents.
DFO indicates deferoxamine; L1, deferiprone; SD, standard deviation; PT, putamen; CN, caudate nucleus; RN, red nucleus.
