儿童气管、支气管非金属异物的影像学诊断

目的 探讨气管、支气管非金属异物的影像学表现，提高对该病的早期诊断率。方法 回顾性分析了60例气管、支气管非金属异物的临床与影像学征象。结果 本组60例中，右侧支气管异物32例，左侧支气管异物22例，主气管异物6例。常见的影像学表现为阻塞性肺气肿51例，纵隔摆动48例。结论 病史及影像学表现是诊断气管、支气管非金属异物的主要手段。     

SARS冠状病毒半胱氨酸蛋白酶3CLpro的克隆表达及分离纯化

SARS（严重急性呼吸综合征）是由一种新型的人类冠状病毒引起的。由于SARS冠状病毒3CL蛋白酶在病毒的复制翻译中起关键作用，所以成为抗SARS药物设计的关键靶标之一。该研究中，利用以pET28a为载体的高效原核表达系统，克隆表达出SARS冠状病毒3CL蛋白酶，然后由NTA-Ni^2＋亲和层析柱对表达的蛋白进行分离纯化。3CL蛋白酶在大肠杆菌表达系统中的成功表达为今后进一步筛选抗SARS病毒药物奠定基础。     

下咽癌淋巴引流的活体显像研究

目的：探讨下咽癌颈淋巴结转移时肿瘤区域引流淋巴结的活体显像方法，从肿瘤活体淋巴引流的角度观察下咽癌前哨淋巴结和颈淋巴结转移的方式，为颈淋巴结清扫术提供指导信息。方法：在表面麻醉和喉内镜引导下，用特制的注射针将^99mTc标记的人球蛋白注入20例下咽癌的肿瘤部位，在注射后不同时间采用SPECT扫描观察放射性核素通过淋巴扩散的过程及其在引流淋巴结内的浓集，以明确前哨淋巴结的位置和肿瘤颈淋巴结引流过程。同时对颈淋巴清扫标本进行病理检查。结果：20例肿瘤引流淋巴结均获得满意活体显像，显像的淋巴结最大3．5cm，最小1．0cm；12例梨状窝癌的颈部引流淋巴结位于肿瘤侧，其余8例中线结构的肿瘤颈部引流淋巴结均具有明显的优势偏向，即单侧颈部引流现象，没有出现双侧对称引流的病例。20例肿瘤引流淋巴结主要分布在Ⅱ、Ⅲ、Ⅳ区，未发现Ⅰ区和Ⅴ区显像的淋巴结。术后病理证实20例中有16例发现病理阳性淋巴结，且均位于引流优势侧，未出现对侧和双侧颈淋巴结转移的病例。结论：无论是中线结构或偏中线结构的下咽部癌肿，其向颈部的淋巴引流具有明显的优势偏向特点，术前进行引流淋巴结的活体显像对预测肿瘤转移部位和有目的地进行择区性颈淋巴结清扫术具有重要意义。     

Right and left ventricular volume measurements in an animal heart model in vitro: first experiences with cardiac MRI at 1.0 T

The aim of this study was to determine the accuracy in quantifying right and left ventricular volumes using a 1.0-T system and commercially available, standard equipment. For exact comparison of MRI measurements and real volumes we used an animal heart model ex vivo. Eight pig hearts were explanted and prepared by removal of the atria. Aorta and pulmonary truncus were cannulated. Definable volumes were injected into the ventricles. Magnetic resonance imaging was performed at 1.0 T (Gyroscan T10 NT, Philips, Eindhoven, The Netherlands); sequence: fast field echo–echo planar (multishot EPI); body coil; MR software: Cardiac Application Package (Philips). Statistical analysis correlated the real volumes and MR measurements separately for both ventricles and two investigators (SAS, ANOVA). For both ventricles and both investigators the correlation between real volumes and MR measurements was greater than 0.99. There was no significant systematic false estimation for both ventricles. Magnetic resonance imaging at 1.0 T using standard hardware and software equipment enables the quantification of right and left ventricular volumes with high approximation to the real volumes in vitro. There is a clear restriction in translating these data into a clinical application because under experimental conditions no motion-induced artifacts existed. Received: 22 July 1999; Accepted: 27 August 1999     

心肌灌注显像放射性稀疏区成因与组织衰减的实验研究

目的探讨正常心肌灌注显像放射性稀疏区的成因.材料与方法对5例猪心行99mTc-MIBI在体和离体心肌灌注显像,并用ROI技术测量左室各部位心肌的放射性水平(计数/像元),由该值在两种状态下的差值计算衰减程度(%).结果两种状态间壁后部和后壁放射性水平最低;在体心肌前壁中段衰减程度(7.9%)高于其前段和后段,该区衰减程度与胸壁厚度呈正相关;后壁衰减程度最高(11.9%).结论胸壁是造成前壁中段稀疏影的原因,膈肌是形成后壁稀疏影的重要原因之一.心肌图像重建时可根据衰减程度作适当补偿.     

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。     

Imaging of compressive vertebral haemangiomas

Compressive vertebral haemangiomas (VHs) are rare. Correct preoperative diagnosis is useful both for operative planning (since compressive VHs are extremely vascular lesions) and to allow preoperative embolisation. Numerous radiological signs for VHs have been described, but compressive VHs frequently have atypical features. In particular, magnetic resonance features are not well established. We present imaging features in three cases of compressive VH and review the imaging findings in an additional 106 previously published cases. Findings were typical in 52 of 80 plain film (65 %), 33 of 41 computed tomography (80 %) and 13 of 25 magnetic resonance examinations (52 %). The prevalence of previously described imaging features is reported. Awareness of the range of magnetic resonance features is important since this is frequently the initial investigation in patients presenting with symptoms of neural compression. Since computed tomography is typical in 80 % of cases, this is a useful confirmatory test if magnetic resonance features are suspicious but not diagnostic of compressive VH. Received: 6 August 1999; Revised: 4 November 1999; Accepted: 4 November 1999     

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     

MRI of the brain in cerebrotendinous xanthomatosis (van Bogaert-Scherer-Epstein disease)

The clinical, biochemical and magnetic resonance imaging findings of two patients with cerebrotendinous xanthomatosis are reported. This is a rare hereditary disease. Early recognition of this entity is important in view of the existing treatment possibilities. Magnetic resonance imaging findings typically include a bilateral and almost symmetrical increase of the signal intensity on the T2-weighted images in the cerebellar and periventricular cerebral white matter, the basal ganglia, the dentate nuclei and the brainstem as well as cerebellar and cerebral atrophy. Received: 18 January 1999; Revised: 3 June 1999; Accepted: 7 June 1999