颅内结核瘤的影像学诊断

目的分析31例颅内结核瘤的影像学资料,探讨其诊断和鉴别诊断。方法回顾性分析31例经手术病理（17/31）和抗痨治疗随访（14/31）证实为颅内结核瘤的影像学表现。结果平片示边缘光滑,密度不均的“蛋壳样”钙化。CT示单发或多发,等或混杂密度小结节影,多发病灶较小,病灶0.5～5.5cm;单发病灶偏大,（19/31）＞2cm,周围水肿不明显。增强后呈结节状或环状强化。MRI显示T1WI为低或等信号,T2WI为低、等或高信号,（11/16）增强呈结节状强化,其余无强化。结论典型的颅内结核瘤有特征性影像学表现,非典型病灶需与脑脓肿、脑囊虫、胶质瘤和转移瘤鉴别,必要时采用穿刺活检或手术病理确诊。强化抗痨治疗后复查CT、MRI可帮助鉴别,严格掌握手术适应证,可使病人免于手术治疗。     

中国北方汉族人基质金属蛋白酶1、9、12基因多态性与慢性阻塞性肺疾病易感性的研究

目的探讨基质金属蛋白酶（matrix metalloproteinases，MMPs）基因多态性与慢性阻塞性肺疾病（COPD）易感性的关系。方法采用病例对照研究方法，收集147例吸烟COPD患者和120名吸烟非COPD正常对照。调查研究对象的性别、年龄、吸烟史、职业粉尘接触史、临床症状、体格检查、测定肺通气功能和支气管舒张试验。应用聚合酶链反应、限制性内切酶分析法比较MMP-9（-1562C／T）、MMP-1（-16071G／2G）、MMP-12（-82A／G）、MMP-12（-357Asn／Ser）基因多态性在COPD组和吸烟非COPD对照组的差异。结果MMP-12基因型Asn／Asn和CT／AsnAsn可增加患COPD的危险性。OR值分别为2361（95％CI：1．369～4．017）和2．433（95％CI：1．159～5．342）；CC／1G1G／SerSer对COPD患病有保护作用。OR值为0．457（95％CI：0．231～0．911）。结论CT和AsnAsn两基因型同时存在，可增加COPD的易感性，CC、GG和SerSer三基因型同时存在对患COPD有防护作用；多基因联合作用对多基因遗传病发病的影响比单个易感基因的作用更重要。     

Adult intussusception secondary to inflammatory fibroid polyp: demonstration by MRI

Adult intussusception secondary to inflammatory polyp occurs rarely. Imaging of intussusception on ultrasound, CT and MRI has been previously described. In this report we describe a case of an adult intussusception secondary to inflammatory fibroid polyp. Both the lead point (inflammatory fibroid polyp) and intussusception were depicted on multiplanar MR images. Findings on MRI were confirmed at surgery and histopathological examination. Received: 11 January 2000; Revised: 3 May 2000; Accepted: 4 May 2000     

Juxta-articular hemangioma of long bone

We report on a rare case of an intraosseous hemangioma involving the proximal tibia in a 70-year-old man. Radiographically, the lesion was a well-defined osteolytic lesion with marginal sclerosis. The CT images demonstrated a well-defined osteolytic lesion with partial cortical breakthrough. T1-weighted MR images showed a hypointense lesion, while T2-weighted images revealed hyperintense areas, with internal, hypointense septa. Gadolinium-enhanced T1-weighted images showed lattice-like enhancement of the lesion. Received: 28 December 1999 Revision requested: 3 March 2000 Revision received: 23 May 2000 Accepted: 26 May 2000     

Imaging in isolated sacral tuberculosis: a review of 15 cases

Objective. To review imaging studies of isolated involvement of the sacrum due to tuberculosis and determine the role of imaging in the diagnosis and management of these patients. Design and patients. A retrospective analysis of 15 cases of isolated sacral tuberculosis imaged with MR imaging was performed. The CT images were also reviewed where available, and the various lesion characteristics were identified. We also reviewed the medical records in an attempt to determine the impact of the imaging studies on the management of these patients. Results. Fifteen patients (5 male, 10 female) presented with symptoms of 3–15 months’ duration. Chronic localized backache with muscle spasm was the commonest presenting symptom; discharging sinuses with abscess formation was found in six patients, five of whom were children. MR imaging of the sacrum revealed a hypointense marrow signal on T1-weighted images and hyperintense signal on T2-weighted images in 14 of 15 patients, the S2 vertebra being always involved. CT revealed osteolytic changes in the sacrum in all the five patients in whom CT was performed. All patients showed marked clinical improvement within 1 year of anti-tuberculous chemotherapy. Conclusion. Isolated tuberculosis of the sacrum is uncommon but should be suspected in patients presenting with chronic low backache or children with discharging sinuses/abscesses and showing sacral destruction on CT or MR imaging. MR imaging can identify cases and enables early institution of anti- tuberculous chemotherapy. Received: 31 August 1999 Revision requested: 1 November 1999 Revision received: 27 March 2000 Accepted: 14 April 2000     

Simultaneous display of MRA and MPR in detecting vascular compression for trigeminal neuralgia or hemifacial spasm: comparison with oblique sagittal views of MRI

A new technique, simultaneous display of magnetic resonance angiography (MRA) and multiplanar reconstruction (MPR), was performed by a workstation to identify the involved vessels in patients with trigeminal neuralgia (TN) or hemifacial spasm (HFS), and the results were compared with those of oblique sagittal MRI technique. Twelve patients with either HFS or TN were prospectively assessed by simultaneous display of MRA and MPR, and oblique sagittal techniques, to point out the neurovascular compression and to identify the involved vessels. Three-dimensional (3D) time-of-flight (TOF) spoiled gradient-echo (SPGR) images were acquired to create MRA and MPR. Oblique sagittal views were also created and displayed on films. A total of 15 vessels in 12 patients were identified as compressing vessels during surgery. Simultaneous display of MRA and MPR technique pointed out the presence of vessels at and/or around root entry/exit zone (REZ) in all 12 patients, but proper identification by the name of the individual vessel was correct in 13 of 15 cases. However, oblique sagittal technique indicated the presence of vessels at and/or around REZ in 11 patients, but only 8 of 14 vessels were correctly identified. Our new method, simultaneous display of MRA-MPR, facilitated correct identification of the involved vessels compared with the oblique sagittal view method. Received: 30 June 1999; Revised: 9 September 1999; Accepted: 23 November 1999     

Detection of severe acute pancreatitis by contrast-enhanced magnetic resonance imaging

The aim of the study was to assess the ability of MRI to differentiate between the two forms of severity of acute pancreatitis (AP), which is important for the detection of patients who require intensive monitoring and therapy. The second objective was to evaluate whether the distinction would be possible regardless of the MRI equipment. Magnetic resonance imaging was performed before and after intravenous administration of a gadolinium (Gd) chelate at 1.0 T using the breath-hold multislice rapid gradient-echo turbo fast low-angle shot (FLASH) sequence in 14 patients, and at 1.5 T with the 2D FLASH(50) sequence with fat saturation in 18 patients with acute pancreatitis early in the course of the disease. The patients were classified according to the Atlanta classification system as having the mild (MAP) or severe (SAP) form of the disease. At 1.0 T with use of a body coil, contrast-enhanced MRI failed to distinguish mild from severe pancreatitis. At 1.5 T with a phased-array body coil, the signal intensities of the patients with SAP were statistically significantly lower than those of the MAP group. Our initial clinical experience suggests that MRI with a sufficient magnetic field gradient strength may be useful for separating the two forms of acute pancreatitis in their early phases. Received: 19 January 1999; Revised: 28 May 1999; Accepted: 22 July 1999     

Effect of long-term vigabatrin administration on the immature rat brain

PURPOSE: To determine whether the neuropathologic changes produced by vigabatrin (VGB; gamma-vinyl GABA) administration in the developing rat brain are reversible. METHODS: We injected rats daily with VGB (25-40 mg/kg/day, s.c.) from age 12 days for 2 weeks followed by 2 weeks of a drug-free period. Behavioral testing, magnetic resonance (MR) imaging, biochemical assays, and histologic technique were used to assess the adverse effect of VGB in developing brain and its reversibility. RESULTS: At the end of 2 weeks' VGB administration: (a) there was a hyperactivity and a shortened latency to escape out of cool water; (b) white matter appeared hyperintense in T2 and diffusion-weighted MR images with 4-15% increases in T2; (c) microvacuolation, TUNEL-positive nuclei, and swollen axons were observed in the corpus callosum; (d) myelin staining indicated a reduction in myelination, as did the reduction in activities of myelin and oligodendrocyte-associated enzymes and the decrease in myelin basic protein on Western blots. Two weeks after stopping VGB administration: (a) MR images were normal, and microvacuolation was no longer in the white matter; (b) reduction in myelination reversed partially; (c) the T2 relaxation time remained elevated in the hypothalamus; and (d) the behavioral response remained abnormal. CONCLUSIONS: Long-term VGB administration to young rats causes brain injury, which recovers partially on its cessation. The observed cell death, disrupted myelination, and alterations in behavior indicate a need for further safety assessment in infants and children.     

Quantitative volumetric analyses of brain magnetic resonance imaging from rat with chronic neuroinflammation

Brain inflammation may have a pathogenic role in many neurodegenerative diseases, including Alzheimer's disease. In the present study, we investigated the effects of chronic neuroinflammation upon anatomical changes in two regions of interest in the temporal lobe using high-resolution magnetic resonance imaging techniques. We show that chronic infusion of lipopolysaccharide into the fourth ventricle for 4 consecutive weeks enlarged the lateral ventricles and significantly decreased the size of the hippocampal formation and the temporal lobe region. These changes are comparable to those observed in humans during the early stages of Alzheimer's disease.     

Effect of a neuronal sodium channel blocker on magnetic resonance derived indices of brain water content during global cerebral ischemia

Diffusion-weighted magnetic resonance imaging (DWI) with calculation of the apparent diffusion coefficient (ADC) of water is a widely used noninvasive method to measure movement of water from the extracellular to the intracellular compartment during cerebral ischemia. Lamotrigine, a neuronal Na(+) channel blocker, has been shown to attenuate the increase in extracellular concentrations of excitatory amino acids (EAA) during ischemia and to improve neurological and histological outcome. Because of its proven ability to reduce EAA levels during ischemia, lamotrigine should also minimize excitotoxic-induced increases in intracellular water content and therefore attenuate changes in the ADC. In this study, we sought to determine the effect of lamotrigine on intra- and extracellular water shifts during transient global cerebral ischemia. Fifteen New Zealand white rabbits were anesthetized and randomized to one of three groups: a control group, a lamotrigine-treated group, or a sham group. After being positioned in the bore of the magnet, a 12-min 50-s period of global cerebral ischemia was induced by inflating a neck tourniquet. During ischemia and early reperfusion there was a similar and significant decrease of the ADC in both the lamotrigine and control group. The ADC in the sham ischemia group remained at baseline throughout the experiment. Lamotrigine-mediated blockade of voltage-gated sodium channels did not prevent the intracellular movement of water during 12 min 50 s of global ischemia, as measured by the ADC, suggesting that the ADC decline may not be mediated by voltage-gated sodium influx and glutamate release.