A study on the neuronal mechanism of retrieval of long-term digital memory in human by functional magnetic resonance imaging / 生理学报

To investigate the neuronal mechanism of retrieval of long-term digital memory in healthy volunteers, functional magnetic resonance imaging (fMRI) technique was used in the study. Twenty-two right-handed volunteers were subjected to a long-term digital memory test with block-design. The memory task and control task were adopted in the experiment alternatively. The fMRI data were recorded by a Siemens 1.5T MR machine and analyzed by SPM99. The activated brain regions were shown in the Talairach coordinate. The results showed that the Brodmann's area (BA) 9 region in left middle frontal gyrus was the most activated cortex during the long-term digital memory task. The left medial frontal gyrus, left inferior frontal gyrus, right inferior frontal gyrus, cingulate gyrus, left inferior parietal lobule, left superior parietal lobule, right superior parietal lobule, right middle temporal gyrus, left lingual gyrus, left middle occipital gyrus, right middle brain, cerebellum and right caudate nucleus tail were also involved. The activation in cortices showed obvious left predominance. It is suggested that a series of brain regions with left predominance are involved in long-term digital memory. Left lateral frontal cortex would be the most important structure for information extraction, while the other cortices and their connections may be important for processing and long-term storage of digital information.

Activated brain areas during simple and complex mental calculation--a functional MRI study / 生理学报

Functional magnetic resonance imaging (fMRI) was used to study the activated brain areas of human during simple and complex digital calculation, and to investigate the role of cortical and subcortical structures involved in the mental calculation. Sixteen right-handed healthy volunteers performed mental calculation of simple and complex addition/subtraction respectively, while the fMRI data were recorded by a Seimens 1.5 T MR machine. Block-design was used in the tasks. Two calculation tasks and one base-line tasks were performed for the block-design. Simple calculation task was single-digit addition and subtraction, while the complex was multi-digit addition and subtraction. The base-line task was to tell whether the two numbers were the same in every trial. Statistical parametric mapping (SPM99) was employed to process data and localize functional areas. We compared the average activation intensity of each activated brain regions in the same calculation task and the activation intensity of the same regions in both tasks respectively. Both the cortex and the subcortical structures including basal ganglia and thalamus were activated during simple and complex mental calculations. Similar brain regions in subjects including frontal lobe, parietal lobe, occipital lobe, cingulate gyrus, thalamus and cerebellum were engaged in simple and complex addition/subtraction. In the same task, activation intensity of all activated brain areas differed insignificantly. Compared with the complex task, the right parietal lobe was not activated in the simple one. The subcortical structures such as the caudate nucleus and the left marginal division of the striatum (MrD) were activated in both two calculation tasks. The cortical regions involved in both simple and complex addition/subtraction were similar. In conclusion, both the cortex and the subcortical structures were activated during the mental calculation. The cortex including the frontal cortex, parietal cortex, and cingulate gyrus were activated during mental calculation, while the subcortical structures such as the caudate nucleus, the globus pallidum and the left marginal division of the striatum also played a critical role in the neural networks of the calculation at the same time. Right parietal lobe (supramarginal gyrus) was engaged only in the complex task, which suggested that this region might be involved in the visuospatial memory and processing.

Findings of chest radiograph and spiral computed tomography in Swyer-James syndrome / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the value of X-ray and spiral computed tomography (SCT) in the diagnosis of Swyer-James syndrome (SJS).</p><p><b>METHODS</b>A total of 28 patients, 12 males and 16 females, were studied retrospectively. Ages ranged from 11 to 57 years, the mean age was 32 years. All patients underwent inspiratory chest X-ray films, 5 with expiratory chest films and 1 with bronchogram. Furthermore, inspiratory and expiratory SCT scans were performed. The SCT findings were analyzed and compared with X-ray films.</p><p><b>RESULTS</b>SCT demonstrated 56 lobes with hyperlucency and diminished vascularity. The size of 51 lobes were smaller and 5 were normal. X-ray films showed that hyperlucency was only in 29 lobes, in which 19 lobes were small-sized and the other 10 lobes normal. There were 56 lobes with air-trapping on expiratory SCT scans, but only 5 lobes with air-trapping on expiratory X-ray films. Bronchogram in 1 case demonstrated bronchiectasis and bronchiolitis obliterans. SCT showed 24 patients with bronchiectasis, 9 patients with tuberculosis, 10 patients with bronchiolitis, and 2 with segmental collapse.</p><p><b>CONCLUSION</b>SCT scan is superior to chest radiography in the diagnosis and differential diagnosis of SJS.</p>