Objective To explore the clinical promise of CT 3D reconstruction of tracheobronchial tree(TBT) by analyzing 73 cases retrospectively. Methods All the 73 cases were collected from October 1997 to February 2000, who were scanned by EBCT with 130 kV and 630 mA. The scanning method was continuous volume scan, the slice thickness were 3 mm or 1.5 mm. All cross-sectional images were transmitted to the INSIGHT workstation and reconstructed with SSD (shaded surface display), and the threshold setting were -500 to -300 HU. Results 3D reconstruction of TBT with EBCT could reveal the abnormal changes of TBT by many kinds of diseases including central cancer, inflammation, bronchiectasis, saber-sheath trachea, trachea cancer, congenital disorders, post-surgical changes of lung cancer, and stenoses by adjacent benign or malignant diseases. It could be used to locate the stenoses and measure stenostic extent. Of the 35 central cancer cases with 3D reconstruction, 6 cases were pestle obstructed, 15 cases cone obstructed, 5 cases interrupted irregularly, 8 cases with eccentric stenoses, and 1 case with right stem destroyed and right upper lobe bronchus obstructed. Conclusion 3D reconstruction of TBT has characteristic sign in the diagnosis or differential diagnosis of central airway′s benign or malignant stenoses, and it is of instructional value in clinical use.

Objective:To improve the CT and MRI diagnostic accuracy of intracranial atypical cavernous angiomas(ACA).Methods:We retrospectively analyzed CT and MRI appearances,operative and pathological findings of 12 cases with ACA.Of them,11 cases were seanned by CT,10 cases by MRI and 9 by both CT and MRI.Results:Of 12 cases:One case as located at the sella ,1 case was at the fourth ventricle,5 cases were located at the cerebral hemisphere,4 cases were located at the middle cranial fossa and 1 case was at the posterior cranial fossa.There was edema in 3 cases,1 case had cystic component and 4 cases had cerebral hemorrhage.The localized rate of ACA by CT and MRI was 100%,but 11 cases were misdiagnosis and 1 case did not made the qualitative diagnosis. Conclusion:The qualitative diagnosis of ACA have some difficulty,so that the emphasis should be on the analysis of the combination imagiology and clinic.

Objective To obtain magnetic resonance imaging(MRI) symptoms that could be used in medical diagnosis and identification by analyzing the diverse MRI appearance of brain multiple sclerosis(MS).Methods MRI findings of 41 samples of clinically definite MS, including the numbers, distributions, sizes, and shapes of the lesions were analyzed. The symbolic characteristics and enhanced expression are also covered.Results Brain MS might happen singly and multiply, and more frequently with multiple happening. In a multiple case, 4—15 lesions were observed the most. Some samples showed with diffuse lesions which were unable to be counted accurately presenting as a “dirty-appearing white matter”. The distribution of the lesions was observed most frequently at the two sides of periventricle, and following by the subcortical, corpus callosum, and brainstem. Only two lesions were observed at cerebrum. The size of most lesions range from a few millimeters to 2 cm, accounting for about 75% of the total samples. Lesions with size above 2 cm were seen seldomly, with the biggest one of 6—7 cm. According to the shapes and symptoms, lesions might be categorized as an acute and chronic ones. The acute lesions had a shape of oval or circle, with a swelling appearance, low signal of T_1WI, and isointensity or a slightly higher signal on the circle. T_2WI showed a high signal, with different increase and showing “core+lunar” sign. This kind of lesions showed an enhancement with the circle enhancement as the most typical one, which had a complete circle or non-conplete arc shape enhancement, even the big lesions. The chronic lesion might also be divided into two categories. One was the quasi-symmetric lesion, with the distribution along two sides of periventricle and with the shape of small puncture/patch, part of them merged into the big patch; another kind of lesions was found scattered sparsely at frontal, parietal lobes and two sides of the periventricle, with small patches in shape. The chronic lesions had an appearance of shrinking, sharp edge, even signals, and had no lunar circle phenomena and obvious enhancement.Conclusion Brain MS have diverse MRI appearence, with some of which are unique and symbolic.

Purpose:To investigate the values of three newer contrast enhanced MRI sequences including gadolinium-enhanced FLAIR MRI(CE FLAIR), dynamic contrast-enhanced MRI (DCE MRI) and perfusion- weighted MRI(PWI) by comparing their advantages and disadvantages respectively in the diagnosis of intracranial tumors. Methods:43 patients with intracranial tumors underwent DCE MRI, CE FLAIR and PWI respectively. The gadolinium-enhanced FLAIR, dynamic enhanced MR and perfusion-weighted MR images were evaluated independently by two radiologists for the number of examinations with one or more enhancing lesions, the number and location of enhancing lesions per examination, the detectability for different lesions in different locations, size and extent of the lesions. Results:Perfusion-weighted MR images showed poor quality and could not give a diagnosis in 5 of 43 cases because of heavy susceptibility artifacts. There were 47 lesions in the 38 cases. However, 41 lesions were found on CE FLAIR MR images and 42 on DCE MRI and 45 on PWI. 3 lesions(2 located in the subcortical area and 1 in paraventricle) were only revealed on the CE FLAIR images. 4 lesions in the basal ganglia area were only found on dynamic enhanced images. 7 lesions in the cerebral hemisphere were only found on perfusion-weighted images. So there were significant differences in revealing lesions of different locations with the three MR modalities(P

Objective To assess the clinical history and MRI findings of pituitary adenoma of different hormonesecreting type.Methods We retrospectively studied 200 postoperated patients,from 1996 to 2000,who all had the preoperated MRI exams.All cases had histopathological evalutions.Both clinical presentation(age,sex,symtom,sign)and MRI findings(size,form,signal intensity,extension)were investigated.Results There was a great span of age with sixty percent owing for 35～55 years old.The male and female proportion was 1∶2 in PRL hormone-secreting pituitary adenoma.12 cases with luleinizing hormone-secreting and 2 cases with thyrotropin hormone-secreting pituitary adenoma were just male.In other types the incidences were similar in man and woman.Clinical symptom and sign present overlapping.The volume of tumor was from 0.5 cm?0.8 cm?1 cm to 6 cm?7 cm?8 cm with most multihormone adenoma's maxium dimension out of 5 cm.The signal intensity was not characteristic pre-and post-enhancement.No calcification could be seen.In term of extension,most was to suprasellar,then infrasellar,unilateral or bilateral sinus cavernous,last was to lower part of the third ventricle.Conclusion Different hormonesecreting pituitary adenomas have some speciality in clinical and MRI presentation.Although an accurate diagnosis can not be made according to it,more information have been obtained.

Objective To explore the MRI and pathologic characteristics of hippocampal sclerosis. Methods 16 patients with hippocampal sclerosis were examined with transvers and oblique coronal T 1 weighted,T 2 weighted and fluid attenuated inversion recovery(FLAIR) MR imaging. Results Of 16 patients,1 case had bilateral hippocampal sclerosis;15 cases were ipsilateral(left n =9,right n =6) proved by pathology.The MR features of hippocampal sclerosis were as follows:hippocampal atrophy present in all patients;hyperintensity on coronal FLAIR in all patients and on coronal T 2W images present on 15 sides; loss of superficial sulci hippcampal head seen in 11 sides;disruption of the internal structures present on 13 sides; atrophy of lateral white matter present on 7 sides; enlargement of the ipsilateral temporal horn present on 6 sides;atrophy of the ipsilateral temporal lobe seen on 2 sides. Conclusion Atrophy and hyperintensity on coronal FLAIR and T 2 weighted images were the most common features of hippocampal sclerosis and had positive diagnostic value. Combination of coronal FLAIR and T 2 weighted imaging could improve the diagnostic sensitivity and accuracy for hippocampal sclerosis.

Objective To evaluate the accuracy of MR diffusion weighted imaging (DWI) in the diagnosis of hyperacute cerebral infarction. Methods Twenty one patients with onset of strokelike symptoms underwent conventional MRI and DWI within 6 hours. Results DWI indicated cerebral infarction in 16 patients, all of whom had a final diagnosis of acute stroke. DWI was negative in 5 patients, all of whom had a final diagnosis of TIA. The abnormality seen at DWI was confirmed with follow up study. DWI had a sensitivity of 100% and a specificity of 100% in the diagnosis of hyperacute cerebral infarction, and conventional MRI interpretation yielded a sensitivity and specificity of 25% and 100%, respectively. Conclusion DWI is highly accurate in diagnosing hyperacute cerebral infarction and is superior to conventional MRI.

BACKGROUND: At present, MRI is the key method to examine the hippocampal sclerosis of the patients with epilepsy. The main results are the abnormal signals of hippocampus, in addition, other symbols of MRI can also suggest the hippocampal sclerosis.OBJECTIVE: To study the significance and value of the loss of visualization of digitations of hippocampal head in diagnosis of hippocampal sclerosis through the analysis of MRI on patients with temporal lobe epilepsy.DESIGN: Non-randomized, blind procedure(data selection, result evaluation), blank controlled and clinical experiment.SETTING: Departments of radiology in two universities.PARTICIPANTS: Between September 1996 and December 2002, 18 patients with temporal lobe epilepsy were selected from the Department of Radiology,Xinhua Hospital Affiliated to Shanghai Second Medical University. Meanwhile,patients with headache were diagnosed with MRI. Eighteen healthy people,whose ages were matched, were as control group.METHODS: Among 18 patients, MRI of 16 patients and 18 people in the control group were performed with a GE 1.5T Horizon MR unit and another 2with a GE 1.5T Signa whole body MR unit. With the double blind procedure, whether the digitations of hippocampal head of 72 hippocampal heads of 36 people in both patient and control groups exist or not was recorded by two radiologists with knowledge of hippocampal dissection but without knowing the condition of clinical operation. The results were divided into 3 levels:loss, poorly visible and existing, and hippocampal atrophy and abnormal signals were also recorded.MAIN OUTCOME MEASURES: Image condition of digitations of head,size of hippocampal head and changes of signal.RESULTS: Of 18 patients with hippocampal sclerosis, the abnormal findings included smooth and the loss of visualization of digitations of hippocampal heads seen in 16 patients, poorly visible of digitations of hippocampal head in one patient, and existence of digitations of hippocampal head in one patient. Hippocampal atrophy and high signals on T2-weighted images and fluid-attenuated inversion recovery imaging were seen in all patients. The sensitivity of loss of digitations of hippocampal heads for diagnosis of hippocampal sclerosis was 88.9% (16/18), and the specificity was 100%.CONCLUSSION: The loss of visualization of digitations of hippocampal head is a sensitive indicator for the diagnosis of hippocampal sclerosis. Atrophic changes of hippocampus combining with the increase of T2-weighted signal can definitely diagnose the hippocampal sclerosis.

Objective To study the different patterns of hippocampal atrophy by MRI segmental analysis and to investigate the etiology and pathogenesis of temporal lobe epilepsy Methods GE 1 5 T Signa Horizon LX MRI scanner was used Oblique coronal T 1 weighted images perpendicular to the long axis of the hippocampus were obtained The mesial temporal structures were divided into four parts: the amygdala, hippocampal head, body and tail MRI patterns of atrophy in 50 patients with histologically confirmed hippocampal sclerosis were investigated by MRI volumetric measurement and segmental analysis, and the differences of clinical features and surgical outcome in different groups were compared Results Diffuse hippocampal atrophy was found in 22 of 50 patients (44%), 5 of the 50 patients (10%) showed diffuse atrophy involving both the amygdala and hippocampus 20 of the 50 patients (40%) had hippocampal focal atrophy and 8 of 50 patients (16%) had no obvious atrophy 38 of 50 (76%) hippocampal sclerosis had atrophy in the hippocampal body, 29 of 50 (58%) had hippocampal head atrophy, 24 of 50 (48%) had hippocampal tail atrophy, and the least involved part was the amygdala (16%, 8/50) 10 patients who had normal hippocampal volume showed focal hippocampal atrophy by segmental analysis Various patterns of hippocampal atrophy were found to be statistically related to the duration of epilepsy, the frequency of seizure and the outcome of surgery, respectively ( P 0 05) Conclusion MRI segmental analysis can improve the diagnostic sensitivity of temporal lobe epilepsy and help to investigate its etiology and pathogenesis

0.05). Four lesions were only revealed on CE FLAIR whereas 7 lesions were only found on postcontrast T_1WI. Enhancing lesions located in cerebral hemisphere or the forth ventricle was revealed much more on T_1WI than that on CE FLAIR. However, postcontrast fast FLAIR images may be useful in detecting superficial abnormalities and those located in sulcus or lateral ventricle. The enhancement degree of enhanced T_1WI was much more intense than that of CE FLAIR(P0.05) and statistical significance in GWC, CNR and CER(P