CT理论与应用研究

Advances in Optical Coherence Tomography

Qingming Luo, Yizhe Zhang, Shaoqun Zeng, Jidong Wu, Wei Zhang

2000, 9(4): 1-6.

Abstract(1241) PDF(3)

Abstract:
Optical conference tomography combines advantages of confocal, low coherence, optical heterodyne detection and scanning tomography and realizes non-invasive and in vivo measurement. Since OCT has relatively high spatial resolution and sensitivity, widespread applications are possible for biopsy. In this paper, we will give an introduction to optical coherence tomography (OCT) and then discuss several applications, such as imaging of a canes lesion in the fissure, mucous membrane of internal organs, vessel structure and blood flow dynamics.

Improved Fourier Algorithm of CT Imaging and Experiment

Zhang Tie, Li Jiandong, Li Changjun, Zheng Quanlu, Zhang Jiwu

2000, 9(4): 7-11.

Abstract(1212) PDF(2)

Abstract:
Fourier algorithm is one of the methods for solving Radon transform. Its advantages lie in less operations and faster speed. But because of its poor imaging quality, this algorithm is seldom used in the medical CT field. This paper gives an improved Fourier algorithm and makes the imaging experiments. The result of experiments demonstrates that improved Fourier algorithm and filtered backprojection algorithm are of comparable quality.

Review for the study of image reconstruction algorithms in Voluming CT

Lü Donghui, Zhuang Tiange, Yan Zhuangzhi

2000, 9(4): 12-18.

Abstract(1001) PDF(2)

Abstract:
Voluming CT which is studied later than cross-sectional CT belongs to the field of high-new technology. Compared to cross-sectional CT, it has a lot of advantages, such as the rate of obtaining projections, X-ray utilization ratio and the isotropy of the spatial resolution and density resolution in 3D object. Voluming CT will became one of the more effective methods in medical imaging and industrial nondestructive test. In this paper we introduce the history, the principal characteristics, the algorithmic classifies and the future prospects of the Voluming CT.

A Novel Nuclear Road Inspection Meter

Zuo Honghao, Ding Houben, Cheng Yubao, Wang Xiaozhong, Li Po, Li Zhengrong, Qiu Jianzhong, Li Yonghua

2000, 9(4): 19-22.

Abstract(902) PDF(3)

Abstract:
Because the existing road inspection meters have some defects such as complicated manipulation or small measuring range, we manufacture a novel nuclear road inspection meter based on Compton Back-scatter Scanning (CBS). This paper gives main features of the meter and block schematics of software programs as well as basic algorithms of the data processing.

X-ray And CT Study On Local Hydrothorax

Gu Yeqiang, Yuan Lingjin

2000, 9(4): 23-25.

Abstract(1010) PDF(2)

Abstract:
The authors analyzed the X-ray and CT imaging features of 32 cases with local hydrothorax. The hydrothorax possessed certain specific features. CT also plays an important role in differentiation between local hydrothorax,benign and malignant tumors.

The Wrong Diagnosis Thought Analysis in Multiple Neuroma of Spine

Ma Feng, Tang Hui, Zheng Zhaohua, Hou Zhixiong

2000, 9(4): 26-27.

Abstract(1022) PDF(2)

Abstract:
Multiple neuroma of the spine occurs to children frequently. And these children's ages are often less than 10 years old. There is a multiple neuroma of the spine's sufferer who is a callan in our hospital. It is singularly cased.

X-ray and CT Findings in Mucoceles of Frontal and Ethmoid Sinuses

Wei Ruili, Cheng Jianmin

2000, 9(4): 28-31.

Abstract(1066) PDF(2)

Abstract:
Objective To study the x-ray and CT findings of mucoceles of frontal and ethmoid sinuses and their value of diagnosis. Methods Twelve cases including fifteen mucoceles were studied. X-ray film and CT were performed in all cases .X-ray and CT findings were analyzed and correlated with operative findings. Results Of 15 mucoceles, 9 were found in ethmoid sinuses, 6 in frontal sinuses. Density of sinuses cavity increase in all cases .Sinus expansion, thinning of sinus wall and bony defect were found on X-ray film .CT showed low density with respect to muscle in 11 sinuses, identical in 3 and high density in one case and periphral sinus mucoca enhencement in 3 cases .Sinus expansion and thinning of the sinus wall were found in all cases, the configuration of mucoceles is smooth and clear.Bony defect is obvious in 9 mucoceles and mucoceles invade into adjacent consturctions. Conclusions CT can accuratelly display the bony change and characteristic findings of mucocele and play an important role in diagnosis and differential diagnosis

The CT Diagnosis of Cerebral Tuberculosis In 10 Cases

Pu Zhaoxia, Li Xiuhua

2000, 9(4): 32-34.

Abstract(802) PDF(2)

Abstract:
Objective To discuss the CT diagnosis of cerebral tuberculosis. Materials and Methods The imaging findings of 10 cases with cerebral tuberculosis were analyzed restrospectively. CT scan and enhancement were performed in all 10 cases. Results The 10 cases recorded by surgical or treatment. Conclusion CT examination can diagnosis cerebral tuberculous accurately.

CT Diagnosis of Acute Cervical Trauma

Gao Yan, Xu Junchao

2000, 9(4): 35-39.

Abstract(894) PDF(2)

Abstract:
Purpose: To analyze the CT appearances of acute cervical trauma (ACT)and evaluate the value and limitation of CT in the diagnosis of ACT Methods: 78 cases of cervical trauma were examined with plain film and thin-slice CT 3D Reformations were performed routinely. We analyze and compare X-ray diagnosis with CT diagnosis. Result : 60 cases ACT were diagnosed. CT confirmed 59 cases. 1 cases was demonstrated by X-ray, while missed by CT Fracture detection rates of CT and plain film were 98.3% and 53.3%. Conclusion. CT can also detect if there is Fracture and if the vertebral canal is narrow. That is helpful to treat the patients who have cervical trauma.

3D Seismic Tomography by Using Traveltimes and Waveforms of Multi-phase

So Gu Kim, Qinghe Li

2000, 9(4): 44-47.

Abstract(867) PDF(4)

Abstract:
A new technique of simultaneous inversion for 3-D seismic velocity structure using Pg, Sg, PmP, SmS, Pn and Sn arrival times of 32 events with 404 seismic rays are inverted for locations and crustal structure. These methods are applied to the Central and Southern parts of the Korean Peninsula. 3-D seismic velocity tomography including 8-sections from earth surface to the Moho, 13 profiles along latitude and longitude, and depth distribution was determined. The velocities fluctuate strongly in the upper crust. There are big an-isotrophy bodies near north of Seoul in the upper crust, implying that they may be related to the Chugaryong Rift Zone. They found that there were low velocity bodies beneath the Kyongiu area at the depth 10-15 km, the Youngwol area at the depth 10 km, and the Hongsung area at the depth 5-10 km, indicating that they must be due to the earthquake sources of Kyongju (6/25/1997), Youngwol (12/13/1996), and Hongsung (10/07/1978), respectively. These results are also well consistent with Bouguer gravity anomalies showing very complex and low velocity bodies beneath the Chugaryung Rift Valley and/or deep fault systems and the earthquake hrpocenters, respectively.

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2000 Vol. 9, No. 4