A phantom for facilitating in vitro computed tomographic studies of gallstones

A phantom was designed and constructed for in vitro studies of gallstones using a computed tomographic (CT) scanner. A primary objective of the design was to permit studies of multiple gallstones in a single CT slice. This was accomplished by incorporating in the phantom removable compartments that contain vertically oriented, cone-shaped voids for holding the gallstones and surrounding fluid medium. A slice through the center of the phantom passes through the apex of each cone-shaped holder, and hence through the center of each gallstone. The main body of the phantom is made of water-mimicking plastic, and each compartment can accommodate gallstones ranging up to 3 cm in diameter. Initial experience with the phantom has shown it to be a successful design.     

In vitro dissolution of cholesterol gallstones.

RATIONALE AND OBJECTIVES. Methyl tert-butyl ether (MTBE) is the solvent most commonly used for in vivo dissolution of cholesterol gallstones. Its limitations, however, include high volatility and flammability along with potential toxicologic concerns. Therapy may take several hours. This study was initiated to identify alternate solvents which may be superior to MTBE in one or more of these areas. METHODS. MTBE was compared with several other solvents for cholesterol-dissolving capacity. Groups of human cholesterol gallstones were placed in test tubes, and, without agitation, subjected to mixtures of MTBE:ethanol or another solvent:ethanol. RESULTS. Six other solvents were found to have higher capacities. In several cases, other solvent mixtures dissolved gallstones up to twice as fast as the MTBE:ethanol mixture. These faster solvents were cyclic ethers (tetrahydrofuran [THF], methyl tetrahydrofuran [MTHF], tetrahydropyran [THP], methyl tetrahydropyran [MTHP], and possibly dimethyl tetrahydrofuran [DMTHF]) and limonene. Some of these solvents also have lower volatility and higher flash points than MTBE, resulting in safer storage and handling. THF and pyridine, however, were found to precipitate bile components when mixed with bile. CONCLUSION. The authors describe solvents that may be superior to MTBE for rapid dissolution of gallstones in vivo.     

Dissolution of cholesterol gallstones using methyl tert-butyl ether

Symptomatic cholelithiasis affects a large segment of the population. Several nonoperative therapeutic alternatives for treatment of these gallstones have recently been developed. We present here the technical aspects and results of gallstone dissolution in 75 patients with the use of methyl tert-butyl ether (MTBE) administered via a small percutaneously placed cholecystostomy catheter. Successful stone dissolution was achieved in 69 patients. The average time required for stone dissolution was 12.4 h over an average of 2.4 days, with the success and rate of dissolution being very dependent on technique. Six patients have developed recurrent gallstones. Future efforts will focus on decreasing the labor intensity of the procedure, dealing with the noncholesterol components of gallstones, and preventing gallstone recurrence.     

胆囊颈部结石超声诊断影像学分析

目的探讨超声在胆囊颈部结石诊断中的应用价值。 方法对我院2011年至2019年彩超诊断为胆囊颈部结石的201例患者的超声声像图特征进行回顾性分析。所有患者均在我院普外科接受保胆取石手术时得以证实。 结果201例胆囊颈部结石中有96例出现胆囊体积增大并积液,占47%;176例出现胆囊壁增厚,占87%;47例出现胆泥团,占23%;35例出现胆囊缩小,占17%;145例出现胆绞痛发作史,占72%。 结论在胆囊颈部结石的诊断中,当超声检查出现以下几点应高度提示胆囊颈部结石的可能性：（1）胆囊体积增大合并积液;（2）胆囊壁明显增厚,胆汁暗区呈云雾状改变;（3）胆囊腔内有多个胆泥团;（4）胆囊缩小,胆囊内仅见极少许胆汁;（5）有反复发作的胆绞痛病史。要重点观察胆囊颈部情况,以提高胆囊颈部结石的检出率,减少漏诊。     

Bouveret's syndrome: new cause of double-arch-shadow sign in cholecystosonography

A case of Bouveret's syndrome which later presented as a jejunal obstruction is reported. Special reference is made to the echographic findings. Bouveret's syndrome has a double-arch-shadow image in the zone of the gallbladder bed on ultrasound examination. So far, this sign has been considered specific for gallstones inside the gallbladder.     

MR cisternography: a new method for the diagnosis of CSF fistulae

The aim of this study was to compare a new MRI method for detecting the existence of cerebrospinal fluid (CSF) fistulae, i. e. MR cisternography, with CT cisternography. In a prospective study, 30 patients with post-traumatic CSF fistulae were examined. The MR examinations were performed with a 1.0-T whole-body MR system, using two T2^*-weighted sequences, a 3D PSIF (time-inversed fast imaging with steady-state precession, FISP) and a 3D constructive interference steady-state (CISS) sequence. The results of MRI and CT cisternography were compared with the surgical findings. The sensitivity in detecting CSF fistulae with MR cisternography (PSIF: 89.9 %; CISS: 93.6 %) was higher than with CT cisternography (72.3 %). The sensitivity of CT cisternography at detecting CSF fistulae in patients with a size of dural lesion less than 2 mm or in patients with multiple dural lesions is significantly lower compared with the MR method. Although the localization of CSF fistulae always proved possible with MR cisternography, this could only be accomplished wih CT in 70 % of cases. The MR cisternography technique is a new examination method with a higher sensitivity for the detection of CSF fistulae than CT cisternography. The CISS technique is superior compared with PSIF and should be used in patients with high-flow CSF fistulas. Received 15 July 1996; Revision received 15 January 1997; Accepted 25 February 1997     

胆囊胆汁成分对胆固醇息肉和结石形成的影响

 为探讨胆囊胆汁成分与胆固醇息肉和结石形成的关系,测定了12例胆固醇结石、8例胆固醇息肉和7例非肝胆疾病患者的胆囊胆汁成分.结果显示息肉组和结石组胆固醇浓度均较正常组明显升高,结石组糖蛋白及钙离子浓度明显高于息肉组和正常组,息肉组与正常组pH值接近,均明显低于结石组.提示胆囊胆汁中胆固醇浓度升高是胆固醇息肉和结石形成的病理基础.     

False-positive CT diagnosis of gallstones due to thickening of the gallbladder wall

An erroneous CT diagnosis of cholelithiasis was made at our institution during the past year in seven patients who had thickening of the gallbladder wall. In all cases the mucosa, which had a high attenuation value, was misinterpreted as a calcified stone, and the low-attenuation thickened submucosa was misinterpreted as intraluminal bile surrounding the stone. Depending on the attenuation of the actual intraluminal bile, the pseudostone appeared peripherally calcified (five patients) or uniformly calcified (two patients). Careful analysis of the position and configuration of a suspected stone and of the outer margin of the gallbladder can help avoid an incorrect CT diagnosis of gallstones when high-attenuation thickened mucosa simulates a gallstone and low-attenuation submucosa looks like surrounding bile.     

口服泛影葡胺诊治肠梗阻的临床应用（附4例报告）

口服泛影葡胺用于肠梗阻诊治，除了可预测是否需手术治疗外，对粘连性不全性小肠梗阻兼有治疗作用。     

Sensitivity of ultrasonography for detecting gallstones

Previous studies have overestimated the accuracy of ultrasonography for the diagnosis of gallstones by neglecting the systematic checking of false negative findings. In the present series only 80% of 331 cases of gallstones seen at autopsy had been detected by ultrasonography. The most frequent reason for a false negative finding was the small size of the gallstones.     

Logistic discriminant parametric mapping: a novel method for the pixel-based differential diagnosis of Parkinson's disease.

Positron emission tomography (PET) and single-photon emission tomography (SPET) imaging of the dopaminergic system is a powerful tool for distinguishing groups of patients with neurodegenerative disorders, such as Parkinson's disease (PD). However, the differential diagnosis of individual subjects presenting early in the progress of the disease is much more difficult, particularly using region-of-interest analysis where small localized differences between subjects are diluted. In this paper we present a novel pixel-based technique using logistic discriminant analysis to distinguish between a group of PD patients and age-matched healthy controls. Simulated images of an anthropomorphic head phantom were used to test the sensitivity of the technique to striatal lesions of known size. The methodology was applied to real clinical SPET images of binding of technetium-99m labelled TRODAT-1 to dopamine transporters in PD patients (n=42) and age-matched controls (n=23). The discriminant model was trained on a subset (n=17) of patients for whom the diagnosis was unequivocal. Logistic discriminant parametric maps were obtained for all subjects, showing the probability distribution of pixels classified as being consistent with PD. The probability maps were corrected for correlated multiple comparisons assuming an isotropic Gaussian point spread function. Simulated lesion sizes measured by logistic discriminant parametric mapping (LDPM) gave strong correlations with the known data (r(2)=0. 985, P<0.001). LDPM correctly classified all PD patients (sensitivity 100%) and only misclassified one control (specificity 95%). All patients who had equivocal clinical symptoms associated with early onset PD (n=4) were correctly assigned to the patient group. Statistical parametric mapping (SPM) had a sensitivity of only 24% on the same patient group. LDPM is a powerful pixel-based tool for the differential diagnosis of patients with PD and healthy controls. The diagnosis of disease even before clinical symptoms become apparent may be possible, and ultimately this technique could be most useful in differentiating between several neurodegenerative disorders, incorporating images of multiple neuroreceptor systems.     

对低密度脂蛋白胆固醇直接测定法的评价

国内实验室采用聚乙烯硫酸盐 (ＰＶＳ)沉淀分离法测定血清低密度脂蛋白胆固醇 (ＬＤＬ -Ｃ) [1] ,此法操作简单 ,不需特殊仪器 ,但标本需要预处理 ,不适于自动分析仪使用。另一种常用的方法是用Ｆｒｉｅｄｅｗａｌｄ公式[2 ] 计算ＬＤＬ -Ｃ ,优点为简便、快速 ,但此法影响因素多 ,准确度较差。国外近几年已有几种不同类型的直接法测定血清ＬＤＬ -Ｃ问世[3 ,4 ] ,标本不需要预处理 ,可用于自动化分析仪测定 ,标本用量少 ,重复性好。作者将直接法与ＰＶＳ沉淀分离法作了比较 ,并对直接法性能作了实验评价 ,现报告如下。1　材料和方法1 1　标…     

Acetabular labral tears: diagnosis, repair, and a method for labral reconstruction

Labral tears are an important cause of hip pain in the athlete. Knowledge of labral function is now better understood. The labrum acts as a suction seal stabilizing the hip joint. After a detailed history and physical examination, imaging workup is done to achieve an accurate diagnosis. Hip arthroscopy can be performed to treat labral tears in a minimally invasive manner. This article describes operative techniques to treat labral tears, including a method for labral reconstruction using the iliotibial band autograft.     

Logistic discriminant parametric mapping: a novel method for the pixel-based differential diagnosis of Parkinson’s disease

Positron emission tomography (PET) and single-photon emission tomography (SPET) imaging of the dopaminergic system is a powerful tool for distinguishing groups of patients with neurodegenerative disorders, such as Parkinson’s disease (PD). However, the differential diagnosis of individual subjects presenting early in the progress of the disease is much more difficult, particularly using region-of-interest analysis where small localized differences between subjects are diluted. In this paper we present a novel pixel-based technique using logistic discriminant analysis to distinguish between a group of PD patients and age-matched healthy controls. Simulated images of an anthropomorphic head phantom were used to test the sensitivity of the technique to striatal lesions of known size. The methodology was applied to real clinical SPET images of binding of technetium-99m labelled TRODAT-1 to dopamine transporters in PD patients (n=42) and age-matched controls (n=23). The discriminant model was trained on a subset (n=17) of patients for whom the diagnosis was unequivocal. Logistic discriminant parametric maps were obtained for all subjects, showing the probability distribution of pixels classified as being consistent with PD. The probability maps were corrected for correlated multiple comparisons assuming an isotropic Gaussian point spread function. Simulated lesion sizes measured by logistic discriminant parametric mapping (LDPM) gave strong correlations with the known data (r ²=0.985, P<0.001). LDPM correctly classified all PD patients (sensitivity 100%) and only misclassified one control (specificity 95%). All patients who had equivocal clinical symptoms associated with early onset PD (n=4) were correctly assigned to the patient group. Statistical parametric mapping (SPM) had a sensitivity of only 24% on the same patient group. LDPM is a powerful pixel-based tool for the differential diagnosis of patients with PD and healthy controls. The diagnosis of disease even before clinical symptoms become apparent may be possible, and ultimately this technique could be most useful in differentiating between several neurodegenerative disorders, incorporating images of multiple neuroreceptor systems. Received 8 April and in revised form 23 June 1999