Magnetic source imaging in the preoperative localization diagnosis and prediction of curative effect of focal cortical dysplasia / 中华放射学杂志

Objective To assess the diagnostic value of magnetic source imaging(MSI) in the preoperative localization of focal cortical dysplasia(FCD). Methods Eighty-two patients with intractable epilepsy resulting from FCD undergone preoperative assessment including MSI, video electroencephalography(VEEG) and electrocorticography(ECoG)from February 2006 to June 2012.The consistency between pre- and intra-surgical assessment was evaluated. For patients who had consistent results,postoperative curative effect was also recorded. The accuracy and predictive values of noninvasive preoperative tests were compared by χ2 test. Results For MSI and ECoG, their results were consistent in 57 cases, partially consistent in 14 cases, and inconsistent in 11 cases. In the postoperative follow-up of 57 patients with consistent results, there were 46 cases with Engel class Ⅰ, 3 cases with Engel class Ⅱ, 4 cases with Engel class Ⅲ, and 4 cases with Engel class IV. For VEEG and ECoG, the results were consistent in 43 cases, partially consistent in 33 cases, inconsistent in 6 cases.The postoperative follow-up showed that 27 cases were graded as Engel classⅠ, 5 cases as Engel classⅡ,7 cases as Engel classⅢ, and 4 cases as Engel class IV. There were statistically significant differences(χ2=5.023,P=0.025)of the concordance rate with ECoG between MSI(69.51%,57/82)and VEEG(52.44%,43/82). In the postoperative follow-up of patients with consistent results, the curative effect was better in group MSI than in group VEEG (χ2=3.989,P=0.046). Conclusions Preoperativelocalization by MSI shows advantage over VEEG, which meanswhen it achieves an agreement with ECoG, patients with FCD may get better prognosis from the surgical process.

3.0T MRI study of pituitary lesions in children with short stature caused by growth hormone deficiency / 实用放射学杂志

Objective To study the MRI features of pituitary lesions in children with short stature caused by growth hormone de-ficiency.Methods The MRI findings of clinical and pathological confirmed pituitary lesions in 40 children were retrospectively re-viewed.All cases had 3.0T MRI examination.Results The pituitary lesions included hypoplasia of antehypophysis (25 cases),pitu-itary stalk interruption syndrome (3 cases),pituitary atrophy after craniopharyngioma excision (2 cases)and pituitary hyperplasia (10 cases).MRI of antehypophysis hypoplasia showed that the height of antehypophysis was less than normal.Pituitary stalk inter-ruption syndrome showed not only hypoplasia of antehypophysis,but also absence or marked thinning of pituitary stalk and ectopic bright signal of posterior pituitary lobe on T1 WI.Atrophy of the pituitary was seen after resection of craniopharyngioma,and the stalk was unclear.All of the pituitary hyperplasia were caused by hypothyroidism.MRI of pituitary hyperplasia displayed antehy-pophysis enlargement and upward apophysis symmetrically.There were no pituitary stalk interruption,translocation and abnormal signal.The pituitary hyperplasia had obvious homogeneous enhancement.Pituitary gland reduced in size after replacement therapy. Conclusion MRI can show the features of pituitary lesions in children with short stature caused by growth hormone deficiency clear-ly.Correct diagnosis can be made and the therapeutic effect can be monitored combining with clinical manifestation.

Application of magnetic source imaging in localizing the epileptic foci in patients with grey matter heterotopia / 中华放射学杂志

Objective To evaluate the value of magnetic source imaging(MSI) in localizing the epileptic foci of patients with histologically proved grey matter heterotopia(GMH) and seizure. Methods MSI examinations were performed on 8 patients with GMH and seizure. The location of the epileptic foci defined by MSI was compared with the results of the ECoG. After imaging examinations, all patients received operation with 13-48 months follow up to observe the effectiveness of the operation. Results Among the 8 patients, 1 had hippocampal sclerosis,2 had focal cortical dysplasiaof type Ⅰ B and 1 had focal cortical dysplasia of type Ⅱ B. MRI showed normal findings in 2 cases, subcortical heterotopia in 4 cases, and nodulor heterotopia in 2 cases with one having schizencephaly. The epileptic foci defined by MSI were at right temporal lobe in 2 cases, left frontal lobe in 2 cases, biparietal lobe in1 case, left parietal lobe in 1 case, left temporal lobe in 1 case, and left frontal-parietal lobe in 1 case. The epileptic foci defined by MSI were completely overlaid with area of GMH in 4 cases, closely behind the area of GMH in case, and partly overlaid with area of GMH in 1 cases with size larger than that of the latter. One patient showed two epileptic foci with one located within the area of GMH and the other one 2 centimeters anterior to the area of GMH.One case's epileptic focus located 2 centimeters posteolateral to the area of GMH . The locations of the epileptic foci defined by MSI showed no difference with those defined by ECoG in all patients. According to Engel classification of treatment effect of epilepsy, 6 patients achieved Engle class Ⅰ ( seizure free after operation ), and 2 patients Engel class Ⅳ ( no changes in the frequcenty of occurrence of seizures before and after operation ). Conclusion MSI can noninvasively and precisely localize the epileptic foci before operation in patients with GMH and seizure.

MRI characteristics of various pathological subtypes of focal cortical dysplasia / 中华放射学杂志

Objective To summarize MRI findings of focal cortical dysplasia (FCD), analyze MRI characteristics of various pathological subtypes of focal cortical dysplasia. Methods Forty-four patients with FCD were collected. Their MRI findings were analyzed retrospectively. According to pathologic findings, these patients were divided into FCD type Ⅰ group and FCD type Ⅱ group. The following MR signs were observed in the two types of FCD: ( 1 ) Focal thickening of the cortex. ( 2 ) Blurring of the gray matter-white matter junction. ( 3 ) Tapering of white matter signal intensity alteration toward the ventricle on FLAIR and on T2WI. (4)Focal brain hypoplasia. (5)Increased signal intensity of gray matter on FLAIR. (6)Increased signal intensity of gray matter on T2 WI. ( 7 ) Increased signal intensity of subcortical white matter on FLAIR.(8) Increased signal intensity of subeortical white matter on T2WI. (9) Decreased signal intensity of subcortical white matter on T1 WI. The χ2 tests and corrected χ2 tests were used for comparison between the two groups. Results In the 44 cases, there were 30 cases with FCD type Ⅰ and 14 cases with FCD type Ⅱ. FCD was identified by MRI in 32 cases. Blurring of the gray-white matter junction is the most common sign of FCD (23 cases). There were 21 cases identified by MRI in FCD type Ⅰ group. Focal brain hypoplasia is a typical sign of FCD type Ⅰ , which was found in 11 cases in FCD type Ⅰ group but none in FCD type Ⅱ group. There was statistically significant difference between the two groups (continuity corrected χ2 =5. 0286,P =0. 0249) . In FCD type Ⅱ group, 11 cases were identified by MRI. Increased cortical thickness was found in 10 eases in FCD type Ⅱ group and 11 cases in FCD type Ⅰ group ( χ2 =4. 6234 ,P =0. 0315). Increased signal intensity of subcortical white matter on FLAIR was found in 9 cases in FCD type Ⅱ group and 7 cases in FCD type Ⅰ group (χ2 =6.9180,P =0.0085). Tapering of white matter signal intensity alteration toward the ventricle was found in 4 cases in FCD type Ⅱ group and none in FCD type Ⅰ group ( continuity corrected χ2 = 6. 2883, P = 0. 0122). The above-mentioned three MRI findings showed statistically significant difference between the two groups and were features of FCD type Ⅱ.All of the other MRI findings showed no statistically significant difference between the two groups. Conclusions Different pathological subtypes of FCD have different MRI characteristics. It is helpful to make preoperative diagnosis and planning.

Localization of linguistic center of auditory function in presurgical epileptic patients with magnetic source imaging / 中国医学影像技术

Objective To assess the value of magnetic source imaging (MSI) in localizing the linguistic center of auditory function of epileptic patients before operation. Methods Epileptic focus and the linguistic center of auditory function in 24 patients were localized with MSI before operation. And the relationship between epileptic focus and auditory language area was observed. Results The linguistic center of auditory function was localized in left temporal lobe in 14 patients, in right temporal lobe in 5 patients and in bilaterial temporal lobe in 5 patients. Epileptic focus was localized in left temporal lobe in 14 patients, in left temporal lobe and left parietal lobe in 1 patient, in right temporal lobe in 4 patients, in right temporal lobe and parietal lobe in 1 patient, in left frontal lobe and left temporal lobe in 1 patient, in right frontal lobe, right temporal lobe and parietal lobe in 1 patient, and in bilaterial temporal lobe in 2 patients. Epileptic focus was superimposed with the linguistic center of auditory function in 10 patients, while was not superimposed with the linguistic center of auditory function in 10 patients. The epileptic focus was localized in front of the linguistic center of auditory function in 3 patients, in behind of the linguistic center of auditory function in 1 patient. The lesion of the patient suffered from dysembryoplastic neuroepithelial tumor was not excised completely because the epileptic focus was superimposed with the linguistic center of auditory function, and the patient appeared language functional disturbance after operation in short period, remaining auditory hallucination occasionally after operation. Conclusion Epileptic focus and the linguistic center of auditory function can be localized accurately and the relationship between them can be observed clearly with MSI. MSI is useful to reduce the occurrence of language disturbance after operation.

Changes of Magnetoencephalography during Stretching and Flexing Forefinger under Optical Instructions in One Hemiplegic Patient before and after Rehabilitation Training / 中国康复理论与实践

@#Objective To observe the changes of magnetoencephalography (MEG) during stretching and flexing forefinger in one hemiplegic patient before and after rehabilitation training.MethodsThe cerebral electromagnetic wave of one hemiplegic patient during stretching and flexing both forefingers was recorded by MEG and superposed with magnetic resonance imaging (MRI) to form magnetic source imaging (MSI). The changes of MEG before and after rehabilitation training were analyzed.ResultsThere was no movement evoking magnetic fields in right hemisphere motor cortex at two MSI detections, but detected in left hemisphere motor cortex. The latent period of the first and the second detection was -34.2 ms and -61.7 ms respectively. The exiting motor cortex was located in precentral gyrus. The exiting motor cortex at the second detection was located more front medial and low than at the first detection. The volume of the exiting motor cortex (9569.6 m3) at the second detection was more larger than the first detection (2309.7 m3). There was no movement evoking somatosensory magnetic fields in right hemisphere motor cortex at first MSI detection, but found at the second detection, the latent period was 91.1 ms, and the exiting cortex was located in postcentral gyrus.ConclusionThe cortex somatosensory function of patient with stroke recovers early than the motor function and the uninjured hemisphere function can improve obviously after rehabilitation training.

Localization of the human language cortex by magnetic source imaging / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To localize the language cortex associated with Chinese word processing by magnetic source imaging (MSI).</p><p><b>METHODS</b>Eight right-handed and one left-handed healthy native Chinese subjects were examined by magnetoencephalography (MEG) and a 1.5T magnetic resonance imaging (MRI) unit. All subjects were given pure tone stimuli 50 times, 150 pairs of Chinese words (meaning related or unrelated) auditory stimuli, and pure tone stimuli subsequently 50 times. Evoked response fields time locked to the pure tone and Chinese words were recorded using a whole-head neuromagnetometer 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 unrelated pairs of words. The data obtained by MEG were superimposed on MRI, using a GE Signa 1.5T system.</p><p><b>RESULTS</b>MEG, showed there were two obviously higher magnetic waves named M50 and M100, which were localized in the bilateral transverse temporal gyri in all subjects. The responses to the pairs of Chinese words (meaning related or unrelated) were similar in the same hemisphere of the same subjects. There was a higher peak during 300 - 600 ms in the right hemisphere of one left handed subject, but no peak in the left hemisphere, indicating that the language dominant hemisphere was localized in the right hemisphere. Superimposing the MEG data on MRI, the language area was localized in the Wernicke's areas. A 300 - 600 ms response peak was obsarved in each hemisphere (the amplitude of the 300 - 600 ms response peak in each hemisphere was almost the same) in two right-handed subjects, showing that the language area was localized in the 2 hemispheres in the two subjects. There was one peak in each hemisphere (300 - 600 ms response) in 6 subjects, but the amplitude of the wave in the left hemisphere in the 6 subjects was much higher than that in the right hemisphere. By choosing randomly from the later component (300 - 600 ms response) several time points and superimposing them on MRI, all time points were localized in the posterior part of the superior temporal gyri, which is the Wernicke's areas.</p><p><b>CONCLUSIONS</b>Comparing with the later component of the bilateral hemispheres, the wave amplitude in the language dominant hemisphere was much higher than that in the non-language dominant hemisphere. The language areas could be identified by judging whether meanings of pairs of Chinese words were related or not.</p>

Localization of the human primary auditory cortex by magnetic source imaging / 中华放射学杂志

0.05). Conclusions The primary auditory cortex could be precisely localized by MSI.

Manifestation of magnetic source imaging in patients with refractory epilepsy and encephalomalacia / 中华放射学杂志

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.