PMC2698060_01
A 10-month-old boy with sequelae of severe motor deficit.. A. Axial fast spin-echo T2-weighted MR image (TR/TE=3500/120) shows symmetric high signal intensity in the bilateral thalami.. B. Axial T2*-weighted gradient-echo MR image (TR/TE=800/30, flip angle = 20 ) at the same level as A shows conspicuous low signal intensity within the thalamic lesions, possibly due to the presence there of acute petechial hemorrhage.. C. Apparent diffusion coefficient (ADC) map of diffusion imaging reveals low ADC in the thalamic lesions (arrows), which may represent the presence of cytotoxic edema. In the central portion of the lesions, however, ADC is high, suggesting tissue necrosis.. D. Short echo-time proton MR spectrogram (STEAM 3000/30) of a thalamic lesion shows increased glutamate/glutamine complex peak intensities at 2.0-2.5 ppm and lipid/lactate complex peak intensities at 0.8-1.5 ppm, as compared with an age-matched control subject (E). Broadening of the line-width may be caused by the occurrence of petechial hemorrhage within the lesion.. E. Short echo-time proton MR spectrogram (STEAM 3000/30) of normal thalamus in a 9-month-old age-matched control subject.. Note.-Ins=myoinositol, Cho=choline compound, tCr=creatine complex, Glx=glutamate/glutamine complex, NAA=N-acetyl aspartate
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F1
T1- and T2-prolonged areas in the thalami (Fig. 1A), tegmentum of the pons, and periventricular white matter. T2*-weighted gradient-echo images (TR/TE = 800/30, flip angle = 20 ) demonstrated low signal intensities within the thalamic lesions, suggesting acute hemorrhage (Fig. 1B). Diffusion-weighted MR imaging (b value=1000 sec/mm2) demonstrated high signal intensity in all the lesions, though this was absent in the central portion of thalamic lesions, and other than in this same area, apparent diffusion coefficient (ADC) mapping revealed low signal intensity (Fig. 1C). Localized proton MR spectroscopy of the thalami using a stimulated echo-acquisition mode sequence (TR/TE=3000/30, 96 acquisitions, volume of interest=7 mL) showed that compared with an age-matched control subject, peak intensities were higher, occurring at 2.0-2.5 and 0.8-1.5 ppm (Figs. 1D, E).
PMC2698060_02
A 6-month-old girl without significant neurologic sequelae.. A. ADC map of diffusion imaging shows that the thalamic lesions have a concentric appearance. They have high-signal centers with low-signal rims (arrows), and the ADC values of their remaining portion are high.. B. Initial proton MR spectrogram (STEAM 3000/30) of a lesion shows a small lactate peak (arrow). The N-acetyl aspartate peak is within the normal range.. C. Follow-up proton MR spectrogram (STEAM 3000/30) obtained one week later shows no lactate peak (arrow). The N-acetyl aspartate peak shows no interval change and is still within the normal range.. Note.-NAA=N-acetyl aspartate
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F2
After the intravenous administration of gadolinium-diethylene triamine penta-acetic acid, the lesions showed no abnormal enhancement and ADC mapping revealed areas of low signal intensity within them (Fig. 2A). Localized proton MR spectroscopy using a stimulated echo-acquisition mode sequence (TR/TE=3000/30, 96 acquisitions, volume of interest=7 mL) showed a small doublet at 1.33 ppm (Fig. 2B). The extremities gradually became less rigid, and follow-up brain MR imaging and MR spectroscopy performed one week later revealed marked improvement of the initial lesions and disappearance of the doublet at 1.33 ppm (Fig. 2C).