2006年 · 第119卷第15期

Functional magnetic resonance imaging (fMRI)has been widely used in basic research in the past decade, and more clinically in recent years.Unlike conventional MRI that demonstrates the anatomy and morphology of the brain, fMRI provides the functional information of the brain, including neuronal activation, perfusion, diffusion, metabolism,and fiber connection. Since the publication of the pioneer study by Ogawa et al1 in 1990, blood oxygenation level dependent (BOLD) technique has been adopted by neuroscientists and psychologists in research into the mechanisms of motion, vision,hearing, language, memory, and functions of the brain. Soon after, clinical studies with BOLD technique were conducted in some fields like surgery (surgical planning). In China, however, basic and clinical studies on fMRI in the early years were limited by the shortage of funding, difficulty in integrating personnel of different disciplines from different institutions, and long-term use of MR scanners. In recent years, the studies on fMRI in this country have been flourishing as the conditions are greatly improved, and the number of published papers has increased because more and more radiologists and clinicians are involved。

Abstract：Background Diffusion tensor imaging (DTI) is a noninvasive imaging technique for the assessment of theintegrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampalformation (HF) in patients with medial temporal lobe epilepsy (MTLE).Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity (MD) andfractional anisotropy (FA) from the symmetrical-voxel sampling regions of the anterior HF were calculated in allsubjects. The MD and FA values were compared across the groups.Results No significant differences of MD and FA values were noted between right and left HF in the controls.In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [(9.27±1.09)×10-4mm2/s], compared with the values in the contralateral HF [(8.20±0.59)×10-4 mm2/s] (t = 4.479, P = 0.001) andhealthy subjects [(7.58±0.51)×10-4 mm2/s] (P＜0.001), but no significant differences were found in FA. Whencompared with the controls, patients had a significantly higher MD inthe contralateral HF (P＜0.05), but thedifference in FA was not statistically significant.Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpfulfor preoperative evaluation of such patients。

Abstract：Background Creutzfeldt-Jakob disease (CJD), a rare disease, is uncharacterized by computed tomography (CT)and magnetic resonance imaging (MRI). This study was aimed to evaluate the diffusion-weighted MRI (DWI)manifestations of CJD and to discuss their diagnostic value.Methods The findings of T1-weighted MRI (T1WI), T2-weighted MRI (T2WI), DWI and post-contrast MRI in 5patients (3 patients with biopsy-proven CJD and 2 patients with clinically-proven CJD) were retrospectivelyanalyzed in this study.Results Four out of the 5 patients had cerebral atrophy of various degrees. One patient showed symmetric highsignal intensity at the bilateral globus pallidus and the head of the caudate nucleus, with very high signal in thecerebral cortex on the DWI. This patient only had symmetric slightly high signal at the bilateral globus pallidusand putamen on T2WI. One patient had high signal intensity at the basal ganglia and cerebral cortex on DWI, butabnormal T2 signal intensity at the bilateral paraventricular white matter on MRI. Two patients presented withwidely gyri-like high signal intensity at the cortex on DWI, but routine MRI showed bilateral paraventricularlong T2 signal intensity in 1 patient and no abnormal findings in another. No abnormalities were shown by bothroutine MRI and DWI in the last patient.Conclusions DWI is more sensitive than its conventional counterpart in the depiction of CJD. DWI is moresensitive to detect cortical abnormal signal intensity in CJD not detected by T2WI。

Abstract：Background Hyperparathyroidism (HPT) occurs at an early age and has a high disability rate. Unfortunately,confirmed diagnosis in most patients is done at a very late stage, when the patients have shown typical symptomsand signs, and when treatment does not produce any desirable effect. It has become urgent to find a method thatwould detect early bone diseases in HPT to obtain time for the ideal treatment. This study evaluated the accuracyof high field magnetic resonance imaging (MRI) combined with spiral computed tomography (SCT) scan indetecting early bone diseases in HPT, through imaging techniques and histopathological examinations on ananimal model of HPT.Methods Eighty adult rabbits were randomly divided into two groups with forty in each. The control group wasfed normal diet (Ca:P = 1:0.7); the experimental group was fed high phosphate diet (Ca:P = 1:7) for 3, 4, 5, or6-month intervals to establish the animal model of HPT. The staging and imaging findings of the early bonediseases in HPT were determined by high field MRI and SCT scan at the 3rd, 4th, 5th and 6th month. Each rabbitwas sacrificed after high field MRI and SCT scan, and the parathyroid and bones were removed for pathologicalexamination to evaluate the accuracy of imaging diagnosis.Results Parathyroid histopathological studies revealed hyperplasia, osteoporosis and early cortical boneresorption. The bone diseases in HPT displayed different levels of low signal intensity on T1WI and low tointermediate signal intensity on T2WI in bone of stage 0, Ⅰ, Ⅱ or Ⅲ, but showed correspondingly absent, probable,osteoporotic and subperiosteal cortical resorption on SCT scan.Conclusion High field MRI combined with SCT scan not only detects early bone diseases in HPT, but alsoindicates staging, and might be a reliable method of studying early bone diseases in HPT。

Abstract：Background Conventional magnetic resonance (MR) scanning techniques can identify bone marrow (BM)containing mostly fat cells. But they are not able to differentiate BM tumor infiltration, BM fibrosis and normalred BM. This is particularly problematic in assessment of recurrent or refractory hematological malignancy. Thispilot study used dynamic contrast-enhanced MR imaging (DCE-MRI) to evaluate the bone marrow status and todetermine whether several calculated parameters derived from the DCE-MRI correlate with histologicalcharacteristics of marrow, especially with the tumor fraction (TF).Methods DCE-MRI scans were performed in 25 patients with proven or known hematological malignancy whowere about to undergo bone marrow biopsy of the posterior iliac crest. The location chosen for biopsy wasexamined with MRI approximately one hour prior to the biopsy. Time-signal intensity curves (TIC) weregenerated from the region of the iliac crest corresponding to the planned biopsy site. Enhancement parameterswere calculated, including peak enhancement ratio (PER), maximum enhancement slope (Slopemax), time to peak(TTP) and mean time (MT). The biopsy specimen was reported synoptically, with relevant reported parametersincluding cellularity and tumor fraction (TF).Results PER values were significantly higher for the bone marrow tumor infiltration group than for the normalbone marrow group (P＜0.05). A significant positive correlation was found between PER and TF as well asSlopemax and TF. A negative correlation was found between TTP and TF. There was no significant difference inthe mean TTP and MT values between the BM tumor infiltration group and the normal bone marrow group.Conclusions The presence of diffuse bone marrow infiltration in patients with haematological malignanciescould be verified using DCE-MRI。

Abstract：Background Writer's cramp is a type of task specific idiopathic focal dystonia and has an incompletelyunderstood pathophysiology. The present study utilized functional magnetic resonance imaging (fMRI) toinvestigate what type of brain activity correlates with writer's cramp and its physiological mechanism.Methods Ten patients with writer's cramp were age and gender matched with ten healthy control subjects in ablock design. Subjects were scanned by fMRI while performing three consecutive, visually instructive, tasks withMR Vision 2000: (1) suppositional writing, (2) writing with finger and (3) writing with a pencil. Data wasanalysed using AFNI software for groups of patients and controls.Results The patients with writer's cramp showed significant activations of contralateral basal ganglion(especially the putamen), motor cortex (primary sensorimotor cortex, supplementary motor cortex, premotorcortex) and ipsilateral cerebellar hemisphere in writing with a pencil compared with controls; whereas there wasno obvious difference between patients and controls during writing with finger. Furthermore, these differencesexist in the subtractive activated maps for "writing with a pencil" minus "writing with finger" of patients, whenthe activation of subcortical area and insula in controls disappeared.Conclusions Abnormal activations of contralateral basal ganglion, motor cortex and ipsilateral cerebellarhemisphere of the patients with writer's cramp suggest dysfunction of basal ganglion and subcortical-corticalloop might play a pathophysiological role in writer's cramp。

Abstract：Background Evaluation of fetal central nervous system (CNS) agenesis by ultrasonography (US) is frequentlylimited, but magnetic resonance imaging (MRI) has its own advantages and is gaining popularity in displayingsuspected fetal anomalies. The purpose of this study was to explore the value of MRI in detecting fetal CNSagenesis.Methods Thirty-four women (aged from 22 to 35 years, average 27 years) with complicated pregnancies (16-39 weeks of gestation, average 30 weeks) were examined with a 1.5 T superconductive MR unit within 24 hoursafter ultrasonography. Half-Fourier acquisition single-shot turbo spin-echo (HASTE) T2-weighted imaging (T2WI)sequence were performed in all patients, and fast low angle shot (FLASH) T1-weighted imaging (T1WI) sequencewere applied sequentially in seven of them. Comparison of the results was made between the MRI and USfindings as well as autopsy or postnatal follow-up MRI findings.Results The gyrus, sulcus, corpus callosum, thalamus, cerebellum, brainstem, and spinal cord of fetus wereshown more clearly on T2-weighted MR images than on T1-weighted MR images. MRI corrected the diagnosis ofUS in 10 cases (10/34, 29.41%) and the diagnosis was missed only in 1 case (1/34, 2.94%).Conclusion MRI has advantages to US in detecting fetal CNS anomalies and is a supplement to US incomplicated pregnancies。

Abstract：Background Human adipose tissue-derived stromal cells (hADSCs) can be induced to differentiate along anosteoblastic lineage under stimulation of dexamethasone (DEX). Recent studies, however, have questioned theefficacy of glucocorticoids such as DEX in mediating the osteogenesis process of skeletal progenitor cells andprocessed lipoaspirate cells. Is it possible to find a substitute for DEX? Therefore, this study was designed toinvestigate osteogenic capacity and regulating mechanisms for osteoblastic differentiation of hADSCs bycomparing osteogenic media (OM) containing either 1, 25-dihydroxyvitamin D3 (VD) or DEX and determine ifVD was an ideal substitute for DEX as an induction agent for the osteogenesis of hADSCs.Methods Osteogenic differentiation of hADSCs was induced by osteogenic medium (OM) containing either 10nmol/L VD or 100 nmol/L DEX. Differentiation of hADSCs into osteoblastic lineage was identified by alkalinephosphatase (ALP) staining, von Kossa staining, and reverse transcription-polymerase chain reaction assays formRNA expression of osteogenesis-related genes such as type Ⅰ collagen (COL Ⅰ), bone sialoprotein (BSP),osteocalcin (OC), bone morphogenetic protein (BMP)-2, BMP-4, BMP-6, BMP-7, runt-related transcriptionfactor 2/core binding factor α1 (Runx2/Cbfal), osterix (Osx), and LIM mineralization protein-1 (LMP-1).Results von Kossa staining revealed that the differentiated cells induced by both VD and DEX weremineralized in vitro. They also expressed osteoblast-related markers, such as ALP, COL I, BSP, and OC.Runx2/Cbfal, Osx, BMP-6, and LMP-1 were upregulated during VD and DEX-induced hADSC osteoblasticdifferentiation, but BMP-4, BMP-7 were not. BMP-2 was only expressed in VD-induced differentiated cells.Conclusions VD or DEX-induced hADSCs differentiate toward the osteoblastic lineage in vitro. Runx2/Cbfa1,Osx, BMP-2, BMP-6, and LMP-1 are involved in regulating osteoblastic differentiation of hADSCs, but BMP-4,BMP-7 are not. VD, but not DEX, induces expression of BMP-2 during osteogenic induction of hADSCs. VD isan ideal substitute for DEX for osteogenic induction of hADSCs。

Abstract：Background Liver targeting drug delivery systems can improve the curative effects and relieve the cytotoxicityof the chemotherapy drugs in the treatment of liver diseases. Nanoparticles carrying therapeutic drugs arecurrently under hot investigation with great clinical significance. This study was aimed to investigate thedifferent tissue distribution of the adriamycin polybutylcyanoacrylate nanoparticle (ADM-PBCA-NP) in the micebody after an injection via lateral tail vein, and to study the liver targeting effects of ADM-PBCA-NP in differentdiameters on normal mice liver.Methods One hundred and eighty Kunming mice were randomly divided into 6 groups with 30 mice in eachgroup (5 treatment groups of ADM-PBCA-NP in the different diameter ranges, non-conjugated free adriamycininjection was employed as the control group). A single dose of either conjugated or free adriamycin equaled2 mg/kg of body weight was delivered via the tail vein. Five mice in each trail were sacrificed at 5, 15, 30minutes, 1, 5 and 12 hours postinjection, respectively. The adriamycin concentrations in the respectivelycollected liver, kidney, spleen, heart, lung and plasma were demonstrated using a high performance liquidchromatography with fluorescence detector.Results Compared with the control group, adriamycin was hardly detected in the heart muscle of the treatmentgroups (P＜0.05). The nanoparticle-conjugated adriamycin was cleaned up quickly from the kidney tissue. Theadriamycin concentrations of the mice liver and spleen in the experimental groups were significantly higher thanthat in the control group, except for the group with the nanoparticles diameters of (22.3±6.2) nm (P＜0.05). TheADM-PBCA-NP in (101.0±20.3) nm diameter had the highest liver distribution, and the second highestadriamycin distribution in liver was the group of (143.0±23.5) nm diameter (P＜0.05). Moreover, adriamycinwas released slowly in the liver during the detection period in the experimental groups. ADM-PBCA-NP in (22.3±6.2) nm diameter was not distributed in the tissue of the liver, kidney, heart, spleen, and lung.Conclusions ADM-PBCA-NP in 100-150 nm diameter range has the best liver targeting with a characteristicof slow medicine release. It also decreases the medicine distribution in the heart, kidney and lung. In thetreatment of liver cancer, the polybutylcyanoacrylate nanoparticles system has a good liver targeting ability,which increases the anticancer activity and markedly decreases the toxicity of adriamycin。

Abstract：Objective To assess the state of the art of fetal magnetic resonance imaging (MRI) in China.Data sources Both Chinese and English language literatures were searched in the databases of PUBMED(1998-2005) and CNKI (1998-2005), 41 published articles about fetal MRI were selected.Results Fetal MRI can serve as an adjunct tool for ultrasonography because of its excellent soft tissue contrast,high spatial resolution, multiplanar capabilities, large field of view and simultaneous visualization of fetal andmaternal structures. Since the development of ultrafast MRI sequences provides faster scan time and avoidsmotion artifacts, it is widely applied in detecting normal or abnormal fetal development, including the centralnervous system, thoracic region, abdomen and others. In China, experience in fetal MRI has been scanty, but thetechnique will be extensively used in the near future because of its multi-faceted advantages.Conclusions Compared with ultrasonography, MRI as a complementary imaging for fetal screening isprospective in China or other parts of the world because of its multiple superiorities。

Appendiceal mucinous cystadenoma (AMC) is an uncommon disease. The clinical symptoms are non-specific, thus the preoperative diagnosis is very difficult. The importance of recognizing this condition lies in preventing spillage during surgery. At present,the widespread use of computed tomography (CT)for evaluating abdominal disease has increased the detection rate and diagnostic accuracy for AMC.Here, we report the CT appearance of 4histologically proven AMCs。

Diffusion-weighted magnetic resonance imaging (MRI) exploits the properties of randomly moving water molecules in the presence of magnetic field gradients. Within tissue, diffusion of water molecules is restricted by cell membranes, small vessels, axon cylinders, membrane, chemical interactions of water and macromolecules. In the brain, water diffusion exhibits directionality in the orientation along the long axis of white matter. This is referred to as "diffusion anisotropy". Diffusion anisotropy can be measured via diffusion tensor imaging (DTI). There is a class of anisotropy indices that reflect the degree of anisotropy of water diffusion which are related to the degree of architectural and structural coherence within each voxel of the tissue. Fractional anisotropy (FA) was the most frequently used index of anisotropy。

Pterygium is sunlight related, ocular-surface lesion that obscures vision. The morbidity varies in different parts of the same country. Several surveys have shown that the countries nearer the equator have higher rate of pterygium than the other regions, the possible reason is due to the low latitude and stronger exposure to ultraviolet rays.1 The onset of pterygium is closely related to the environment,2including ultraviolet rays, sandstorm, dry climate and so on. Prolonged ultraviolet-B radiation is regarded as a risk factor for pterygium, and that could explain its prevalence is much higher in the low latitude area。

The injection augmentation mammaplasty for cosmetic purpose has been popular recently in China. Two kinds of injectable material are used clinically, autologous fat and biomaterial. The fat injection for breast augmentation is in question with the major problems of progressive fat re-absorption,microcalcification, and fat liquefaction.1 Now, the principal alloplastic biomaterial for injection augmentation mammaplasty in China is hydrophilic polyacrylamide gel (HPAAG). Although thousands of breasts have been augmented with HPAAG and it seems to be a good biocompatible material, some complications develop after HPAAG injection augmentation mammaplasty.2-4 The patients had to undergo surgery to remove the injected HPAAG and associated lesions. Ultrasonography or magnetic resonance imaging (MRI) should be taken preoperatively to demonstrate the distribution of injected HPAAG and associated lesions.5 In this report, the diagnostic value and clinical significance of MRI on the complications of HPAAG breast augmentation were discussed。

Carcinoma of the salivary gland is an uncommon disease, accounting for less than 1% of all head and neck malignant neoplasm.1 Lymphoepthelioma is a malignant tumor of epithelial origin showing varying amounts of reactive lymphocytic infiltrate.Lymphoepithelioma-like carcinoma (LELC) constitutes a significant proportion of salivary gland carcinoma in Chinese and Eskimo populations and is related to Epstein-Barr virus infection.2,3 Carcinoma of the salivary gland has a propensity for early lymphatic metastasis, and thus a swelling of cervical lymph nodes is occasionally the sole initial symptom.It is very vital to consider a multimodality approach including surgery, radiotherapy and chemotherapy for the treatment in the locally advanced disease。

Congenital cleft lip and palate (CLP) is the most common birth defect now in China. The incidence is 1.62‰ according to the data (1988-1992) provided by the National Center for Birth Defects Monitoring.1 It is also one of the congenital anomalies that have excellent prognosis. But severe complications may occur in the cases accompanied some other deformities. Here we report a case of death caused by left-sided posterolateral congenital diaphragmatic hernia (CDH), type Bochdalek, after the cleft operation。