ABSTRACT
Objective To define the range of the normal values of MRI signals of hippocampal formation(HPF) for the diagnosis of early stage Alzheimer's disease and hippocampal sclerosis.Methods MRI signals of 254 normal adults were measured on the transverse section.Results HPF signal intensities were:T1 relaxation times,629±73 ms;T2 relaxation times,83±5.5 ms;and proton density value,5978±651.The T2 value range(χ±2S)was 72～94 ms,and mean 83 ms.T2 value greater than 104 ms will be associated with evidence of hippocampal pathologic changes.The mixed signal intensity of T2WI(30,60,120)were:3907±407,2657±347,1288±174.The signal intensity ratios of T2WI were:1.02,1.07,1.13.Conclusion As for the histological features of temporal lobe cortex and HPF,T1relaxation times and proton density values are matched but T2 relaxation times of HPF are relatively longer.
ABSTRACT
Objective To study the development and shape of the occipital protuberance and its clinical significance with normal cranial CT scans.Methods 3000 cases of normal cranial CT images were selected.There were 1500 males and 1500 females,which were divided into nine age groups.The internal occipital protuberances were observed and measured on bone-window.Results The internal occipital protuberance was seen earlist at four-month-old-infant,and growth with age.The shape of the internal occipital protuberance was classified into four types:single-peak-type,plane-protusion-type,tropezoid-type and irregular-type.The single-peak-type was seen most commonly.Big semilunar depression of the internal occipital protuberance could be seen in patient with magna citern arachnoid cyst.Conclusion The height and shape of normal internal occipital protuberance have many diversities.Big semilunar depression of the internal protuberance is a important sign in diagnosis of magna cistern arachnoid cyst.
ABSTRACT
The distal femoral epiphyses of 18 human foetus and 10 children were studied by microangiographic and histological methods. The results showed that only the articular cartilage is avascular. Characteristic of vascularity in the chondroepiphyses is that the blood vessels coming from inter-condylar fossa are distributed in the center of chondroepiphyses, those coming from medial and lateral aspects of the condyles are distributed in the outer part of the condyles and those closing to epiphyseal plate mainly come from the area superior to the patellar surface and the area superior to the inter-condylar fossa. The secondary center of ossification first takes place around cartilage canal. The increase of the ossification center is faster in the areas adjacent to blood vessels than the areas far from blood vessels. The blood vessels within cartilage canals in the chondroepiphyses transform to epiphyseal vessels which remained as the blood supply to the ossification center during ossification process. Before 2 years of age, the blood vessels supplying the ossification center are 3-5 vessels coming from inter-condylar fossa. After 2 years of age, the blood vessels coming from the area superior to the patellar surface begin to supply the ossification center. After 5 years of age, the blood vessels coming from lateral aspects of the condyles also take part in the supply of the ossification center.
ABSTRACT
Cartilages of 19 human fetuses were studied by microangiographic and histological methods. Blood vessels were enclosed in a special structure, the cartilage canal which were present in individual cartilages from 2～3 months of the fetus. The cartilage canals developed either from the superficial blood vessels which was gradually embedded in the cartilage as it grew, or blood vessels in the cartilage canal grew and divided themselve progressively and penetrated into the deeper part of the cartilage. In addition to the nutritional supply for the centers of the growth of cartilage, the cartilage canal participates directly in the osteogenesis of the secondary centers of ossification.