[en] RSF₉ monoclonal antibody (IgM) against human carcinoma was labeled with ¹³¹I by Iodogen method. The radioimmunoimaging and immuno-localization of ¹³¹I-RSF in human gastric carcinoma xenograft were studied. Results showed the xenografts of gastric carcinoma could be visualized clearly by SPECT after intraperitoneal injection of ¹³¹I-RSF₉ at 48, 72 and 96h. Biodistribution study demonstrated that the ratios of T/NT were increasing from 48 h to 96 h; the highest ratio of tumor to blood was 2.96 +- 0.45. The localization index (LI) of the tumor was 5.18 +- 0.36 at 96 h. The present study indicated that RSF₉ McAb may be highly valuable in the guided localization of gastric carcinoma and that the McAb IgM may also be used for radioimmunoimaging

[en] To evaluate MRI diagnostic value of the embryonal tumors in the spinal canal. Materials and methods: The MRI appearances of 15 cases of histologically confirmed embryonal tumors in the spinal canal were analyzed. (1) Lipoma (3 cases) had characteristic MRI appearance, demonstrating high signal intensity on T₁WI, and moderately high signal on T₂WI. High signal intensity of the lipoma was turned into low signal intensity by fat suppression technique. (2) Dermoids (2 cases) and epidermoid (7 cases) exhibiting low or iso-low signal on T₁WI and high or iso-high signal on T₂WI. All had an iso-intense capsule on T₁WI. However, the two tumors could not be distinguished from each other. (3) Teratoma (3 cases) appeared as a mass of inhomo-generous signals in the spinal canal including soft tissue, fatty tissue and calcification within the same tumor. The diagnosis of embryonal tumors in the spinal canal mainly depend on their MRI appearances, specific tumor location and patient's age

[en] Objective: To evaluate the epileptic focus localization value of MSI in patients with refractory epilepsy and encephalomalacia. Method: MSI examination was proceeded in 11 patients with refractory epilepsy and encephalomalacia. Five of them were treated with gamma-knife; the others were treated with surgery. Results: In the five patients treated with gamma-knife, the result was satisfied in 3 patients, one patient improved significantly, the other one useless. The distance between the encephalomalacia and the epileptic focus was 4cm in one patient; one patient's encephalomalacia was located in right frontal-parietal lobe but the epileptic focus mainly located in right temporal lobe, only a little located around the encephalomalacia. Overall agreement among VEEG, ECoG and MEG (presence of concordant spikes with the same localization shown by three techniques) was obtained in three patients, the areas localized by ECoG were larger than VEEG and MSI in two patients. The localization was different in VEEG, MSI and ECoG in one patient, then he was given a resection of bilateral occipital epileptic focus. The results of patients treated with surgery were satisfied. Conclusion: The MSI localization of epileptic focus in patients with refractory epilepsy and encephalomalacia is precise, and it can direct the advanced clinical treatment. (authors)

[en] Objective: To localize the primary auditory cortex of healthy subjects by magnetic source imaging (MSI), and to study the value of MSI in mapping the auditory cortex of healthy subjects. Methods: Nine right-handed healthy subjects were examined by 306-channel whole-scalp magnetoencephalography (MEG) and 1.5 T MR unit. The subjects included 7 men and 2 women, aged 14 to 47 years (average 31 years). The pure tone stimuli were given to the left and right ears in all subjects with the intensity of 90 dB (sound pressure level, SPL) and frequency of 2 kHz. The pure tone lasted for 8 ms, and the inter-stimulus interval (ISI) was 1 s. The functional brain activity was evoked and the primary auditory cortex was excited. The excited cortex generated a weak magnetic field out of the brain, which could be measured by MEG. The location the primary auditory cortex was observed after superimposing the MEG data on MRI. Results: M50, M100, M150 and M200 (M50, M100, M150 and M200 were the auditory evoked responses occurred at about 50 ms, 100 ms, 150 ms, and 200 ms, respectively after the auditory stimuli) appeared in all subjects. After M50 and M100 were superimposed on MRI, respectively, the equivalent current dipole (ECD) was located at bilateral transverse temporal gyri, corresponding to the primary auditory cortex. The maximal differences of the ECD of M100 between the bilateral hemispheres were 19.1 mm in x-axis, 20.7 mm in y-axis, and 7.1 mm in z-axis. The maximal differences of the ECD of M50 between the bilateral hemispheres were 20.0 mm in x-axis, 21.2 mm in y-axis, and 7.6 mm in z-axis. The ECD locations of the M50 and M100 were quite near in the same subject's corresponding hemisphere (P > 0.05). The biggest differences between M50 and M100 in the same subject's corresponding hemisphere were 3.3 mm in x-axis, 2.0 mm in y-axis, and 1.2 mm in z-axis. The location of primary auditory cortex had no significant difference between bilateral hemispheres among the subjects (P > 0.05). Conclusions: The primary auditory cortex could be precisely localized by MSI

[en] Purpose: To evaluate the diagnostic value of cysticercosis in the fourth ventricle by CSF cinema MRI. Materials and methods: Nine patients with intraventricular cysticercosis in the fourth ventricle were studied. The diagnosis was confirmed by surgery in all cases. All of these patients were examined systematically before the operation and studied with CSF cinema MRI in mid sagittal section and finger-gated scan technique. Results: (1) The path of CSF flow was directly displayed. All cysticercosis presented as a filling defect, and a cyst with a smooth wall. (2) The ventricular compliance was normal in cysticercosis. (3) The cysticercosis in active stage was free in the fourth ventricle and could be rolled over, its shape might change slightly within a cardiac cycle. In the degenerative stage, its wall could adhere to the ependyma and obstruct the CSF flow. Conclusion: CSF cinema MRI can demonstrate the degree of obstruction and pattern of CSF flow in cysticercosis of the fourth ventricle, thereby providing useful information for proper management

[en] Objective: To study the relationships between changes of rhesus monkeys with EAE in MRS and those in histopathology and ultrastructure. Methods: Nine rhesus monkeys were sensitized by the intradermal injection of homologous myelin basic protein or purified bovine MBP in complete Freund's adjuvant. The ratio of Cho/Cr and NAA/Cr was measured in EAE over course and compared with that before attack. Finally, the histologic characters of the disease was confirmed by light microscope and transmission electron microscope. Results: The lesions of acute and chronic form of EAE was extensive. The lesions of chronic form of EAE observed on MRI were multiple and limited, with mild inflammation. The ratios of NAA/Cr in acute and chronic form were decreased (t = 68.66, 5.69, separately, P < 0.05). A lot of vacuolation, hydropic degeneration, and lipofuscin in the axis-cylinders could be observed in both phases. The ratio of Cho/Cr in chronic EAE was increased (t = 3.48, P < 0.05). In acute form of EAE, severe inflammation, necrosis, and destruction of axons were observed in histopathology. However, chronic form of EAE showed marked demyelination. Conclusion: The ratios of Cho/Cr and NAA/Cr by MRS quantitative analysis can be used to determine different stages of the lesion and predict the histopathological feature in EAE in rhesus monkeys

[en] Objective: To localize the language cortex associated with Chinese word processing by magnetic source imaging (MSI). Methods: Eight right handed and one left handed healthy native Chinese speakers, including 5 men and 4 women, aged from 14 to 32 years, were examined by magnetoencephalography (MEG) and 1.5 T MR unit. All subjects were given 50 times pure tone stimuli (intensity was 80 dB sound pressure level), then 150 pairs of Chinese words (the meaning of the words was related or not related) auditory stimuli (intensity was 80 dB sound pressure level), and then 50 times pure tone stimuli at last (intensity was 80 dB sound pressure level). Evoked response fields (ERFs) time locked to the pure tone and Chinese words were recorded in a magnetically shielded room using a whole-head neuromagnetometer (Model Vectorview 306, made by 4-D Neuroimaging company, Finland) in real-time. The acquired data were averaged by the acquisition computer according to the response to the pure tone, related pairs of words and not related pairs of words. The data obtained by the MEG could be superimposed on MRI. Results: There were two obvious higher magnetic waves named M50 and M100 (two peaks occurred about 50 ms and 100 ms after giving the subjects binaurally stimuli). M50 and M100 in all subjects were localized in the bilateral transverse temporal gyri. The responses to the pairs of Chinese words (the meaning of the words was related or not related) were similar in the same hemisphere of the same subjects. There was a higher peak during 300-600 ms in the right hemisphere in the left handed subject, but there was no peak during 300-600 ms in his left hemisphere. It indicated that the language dominant hemisphere localized in the right hemisphere. Superimposing the MEG data on MRI, the language area was localized in the Wernicke's areas. There were two 300-600 ms response peaks in the bilateral hemispheres (the amplitude of the 300-600 ms response peaks in the bilateral hemisphere was almost the same) in two right handed subjects. It implied that the language area localized in the two hemispheres in those two subjects. There was one peak in each hemisphere (300-600 ms response) in 6 subjects, but the amplitude of the wave in left hemisphere in the 6 subjects was much higher than that of the right hemisphere. After giving the auditory task in all subjects and choosing several time points from the later component (300-600 ms response) randomly and superimposing on MRI, all these time points localized in the posterior part of the superior temporal gyri, that was Wernicke's areas. Conclusion: Comparing the later components of the bilateral hemispheres, the amplitude of wave in the language dominant hemisphere is much higher than that of the non-language dominant hemisphere. The judgement of the Chinese words (the meaning is related or not related) could be used in identifying the language areas

[en] Objective: To have acknowledgement of characteristics of normal volunteers visual evoked fields about full field, vertical half field and quadrant field and their dipole location by magnetoencephalography. Methods: The visual evoked fields of full field, vertical half field and quadrant field were detected with 13 subjects. The latency, dipole strength and dipoles' location on x, y and z axis were analyzed. The exact locations of the dipoles were detected by overlapping on MR images. Results: The isocontour map of M100 of full field stimulation demonstrated two separate sources. The two M100 dipoles had same peak latency and different strength. And for vertical half field and quadrant field stimulation, evoked magnetic fields of M100 distributed contralateral to the stimulated side. The M100 dipoles on the z-axis to the lower quadrant field stimulation were located significantly higher than those to the upper quadrant field stimulation. The Z value median of left upper quadrant was 49.6 (35.1-72.8) mm. The Z value median of left lower quadrant was 53.5 (44.8-76.3) mm. The different of two left quadrant medians, 3.9 mm, was significant (P<0.05). The Z value median of right upper quadrant was 40.0 (34.8-44.6) mm. The Z value median of right lower quadrant was 53.8 (40.6-61.3) mm. The different of two right quadrant medians, 13.8 mm, was also significant (P<0.05). Although each of the visual evoked fields waveforms and dipole locations demonstrated large intra- and inter-individual variations, the dipole of M100 was mainly located at area Brodmann 17, which includes superior lingual gyrus, posterior cuneus-lingual gyrus and inferior cuneus gyms. Conclusion: The M100 of visual evoked fields of pattern reversal stimulation is mainly generated by the neurons of striate cortex of contralateral to the stimulated side, which is at the lateral bottom of the calcarine fissure. (authors)