Intra- and interobserver variability in detection and assessment of calcified and noncalcified coronary artery plaques using 64-slice computed tomography

Objective Multislice computed tomography (MSCT) is an emerging noninvasive technique for detecting coronary plaques. The present study investigated agreement in the detection and characterization of coronary plaques and reproducibility of volumetric analysis. Methods A total of 20 patients underwent MSCT coronary angiography using 64 * 0.5 mm detector collimation. Two readers independently visually evaluated all MSCT datasets for the presence of coronary plaques (n = 82 in 262 coronary segments) and then classified them as calcified, mixed and noncalcified. In addition, one of the readers also manually determined total volumes as well as calcified and noncalcified volumes of each plaque. After a period of at least 4 weeks the complete volumetric analysis was repeated. Results Interobserver agreement was good for detection of coronary plaques on the segment level (weighted κ = 0.88, 95% CI [0.76, 0.95]). However, there was only moderate interobserver agreement for plaques classification (unweighted κ = 0.45, 95% CI [0.35, 0.61]). Intraobserver agreement was good for plaque detection on segment level (weighted κ = 0.90, 95% CI [0.77, 0.96]), while it was moderate with respect to their characterization (unweighted κ = 0.65, 95% CI [0.55, 0.80]). There was moderate reproducibility for total plaque volume (limits of agreement = ±6 mm³ at a mean measured volume of 10 mm³ and = ±28 mm³ at a mean measured volume of 100 mm³). Variation of relative differences significantly decreased for total volume and noncalcified volume with increasing mean volume. Conclusions Detection and volumetry of plaques by means of MSCT shows good to moderate reproducibility. Agreement of volume measurements depends on plaque size. Variation of relative differences decrease with increasing mean plaque volume.     

Impact of glucose intolerance on coronary calcified lesions evaluated using multislice computed tomography

Metabolic syndrome has the unique concept that the common occurrence of individual disease components increases the risk of coronary artery disease (CAD). However, some studies suggest that the burden of different CAD risk factors is not equal, and focusing on the whole set of risk factors might neglect the impact of individual factors that could be useful targets for prophylactic therapies. The purpose of this study was to investigate the effect of glucose intolerance on CAD using multislice computed tomography (MSCT). Ninety-eight consecutive patients with at least one traditional CAD risk factor who visited a municipal hospital were enrolled in this study. The risk factors were impaired glucose tolerance (fasting glucose > or = 110 mg/dl or patients with diabetes), low high-density lipoprotein cholesterol (HDL-C, < 40 mg/dl for men and < or = 50 mg/dl for women), hypertriglycemia (triglyceride > or = 150 mg/dl), hypertension (blood pressure > or = 130/85 mmHg), and obesity (body mass index, > 25 kg/m(2) for men and > 23 kg/m(2) for women). CAD was determined by the presence of either stenoses, non-calcified plaques or calcified lesions. The following risk factors were significantly related in univariate logistic models: glucose intolerance and coronary calcified lesions (p = 0.001), and hypertriglycemia and non-calcified plaque lesions (p = 0.048). Multivariate models showed that glucose intolerance was significantly associated with calcified lesions, even after adjustment for gender, age, low HDL-C, hypertriglycemia, hypertension, and obesity (p = 0.018). Our results suggest that glucose intolerance might be closely related to the presence of coronary calcified lesions among traditional CAD risk factors.     

Enhanced characterization of calcified areas in intravascular ultrasound virtual histology images by quantification of the acoustic shadow: validation against computed tomography coronary angiography

We enhance intravascular ultrasound virtual histology (VH) tissue characterization by fully automatic quantification of the acoustic shadow behind calcified plaque. VH is unable to characterize atherosclerosis located behind calcifications. In this study, the quantified acoustic shadows are considered calcified to approximate the real dense calcium (DC) plaque volume. In total, 57 patients with 108 coronary lesions were included. A novel post-processing step is applied on the VH images to quantify the acoustic shadow and enhance the VH results. The VH and enhanced VH results are compared to quantitative computed tomography angiography (QTA) plaque characterization as reference standard. The correlation of the plaque types between enhanced VH and QTA differs significantly from the correlation with unenhanced VH. For DC, the correlation improved from 0.733 to 0.818. Instead of an underestimation of DC in VH with a bias of 8.5 mm³, there was a smaller overestimation of 1.1 mm³ in the enhanced VH. Although tissue characterization within the acoustic shadow in VH is difficult, the novel algorithm improved the DC tissue characterization. This algorithm contributes to accurate assessment of calcium on VH and could be applied in clinical studies.     

The detection of glass foreign bodies.

Roentgenography is a reliable method for detecting glass foreign bodies resulting from trauma. The density of glass in comparison to surrounding tissue almost always provides sufficient contrast for roentgenographic differentiation. This method is slightly compromised by the relative size of the foreign body and the body part being examined, but setting the roentgen ray beam for bone technic and having the patient in different positions facilitate detection of such a foreign body.     

Intra-articular and soft tissue injections by nurses: preparation for expanded practice

Administration of intra-articular and soft tissue injections for rheumatic disease represents an expansion of the nurse's role. To achieve the benefits of improved care for patients, and enhanced practice and job satisfaction for practitioners, preparation for the role must be rigorous and systematic. Here the authors describe a course designed to meet these criteria. They set out the content and outcomes of the course and consider some of the ethical and legal issues surrounding such role expansion.     

Application of vibro-acoustography for detection of calcified arteries in breast tissue.

OBJECTIVE: The relationship between breast arterial calcification and coronary artery calcification and stenosis is currently an area of active research. It has been suggested in the literature that calcified arteries in the breast may be positively correlated with coronary artery disease. The sensitivity of x-ray mammography, the main breast imaging method, is reduced in radiologically dense breasts. In a recent study, we showed that vibro-acoustography, a novel noninvasive imaging technique that is based on the dynamic response of the object to a vibrating force, can detect microcalcifications in the breast regardless of breast density. In this study, we examined the application of vibro-acoustography in detecting calcified arteries in breast tissue. METHODS: Experiments were conducted on 207 postsurgical excised human breast tissue samples. Tissues specimens were imaged with a high-resolution x-ray mammography unit. Each sample with confirmed arterial calcification was then scanned by the vibro-acoustography system, and the resulting image was compared with the corresponding mammogram. We also studied the histologic characteristics of each sample to positively identify the disease and the presence of arterial calcification. RESULTS: Initial mammograms clearly showed 14 calcified arteries. The corresponding vibro-acoustographic images showed all calcified arteries as fragmented linear structures. The vibro-acoustographic appearance of the arteries was highly correlated with their distinctive radiographic appearance, which allowed us to identify all the calcified arteries in the vibro-acoustographic images. CONCLUSIONS: Vibro-acoustography can be used to detect calcified arteries in excised breast tissue. This method may eventually play a role in identifying individuals with an increased risk of coronary artery disease.     

壳聚糖载体介导关节内基因转移：转染效率与基因产品的关系

目的:分析壳聚糖-DNA超微颗粒在关节内的转基因效应。方法:实验于2005-09/2006-06在上海交通大学医学院健康科学研究所骨科细胞与分子生物学实验室完成。实验材料:①模型制备:采用切断内侧副韧带,切除内侧半月板的方法制备骨关节炎兔模型。②基因产品:白细胞介素(interleukin,IL)1Ra基因、IL-10基因。实验分组:15只新西兰兔按随机数字表法分为3组:①空载体对照组(n=3),造模后5d两侧膝关节关节腔注射400μL壳聚糖-PcDNA3.1溶液,共3次,每48h1次。②IL-1Ra基因治疗组和IL-10基因治疗组,每组6只,造模后5d对照侧膝关节关节腔分别注射20μg裸DNA(PcDNA3.1-IL-1Ra或PcDNA3.1-IL-10),实验侧膝关节关节腔注射400μL壳聚糖-DNA超微颗粒(含20μgIL-1Ra或IL-10),注射次数及间隔时间同空载体对照组。实验评估:①采用酶联免疫吸附分析及免疫组织化学检测IL-1Ra和IL-10基因的表达和分布。②苏木精-伊红染色和甲苯胺蓝染色观察骨关节炎软骨组织学变化。结果:纳入新西兰兔15只,均进入结果分析。①IL-1Ra和IL-10基因在关节滑液中的表达:空载体对照组及IL-1Ra基因治疗组对照侧膝关节滑液中未检测到IL-1Ra表达,实验侧于第1次基因注射后7,14d检测到IL-1Ra表达。IL-10基因治疗组对照侧和实验侧均未检测到IL-10表达。②IL-1Ra基因在兔膝关节的分布:IL-1Ra基因治疗组兔软骨表层和中间层部分细胞内表达IL-1Ra,至少持续到第1次基因注射后14d。在滑膜组织中未观察到明显的IL-1Ra表达。③兔骨关节炎软骨组织学变化:空载体对照组呈早期骨性关节炎的典型性改变。苏木精-伊红染色显示软骨细胞坏死,蛋白多糖甲苯胺蓝染色不均一,软骨表层和中间层大部分区域失染,软骨细胞簇聚区域其周围深染。IL-1Ra基因治疗组在软骨损坏方面明显减轻,甲苯胺蓝部分失染。结论:①壳聚糖-DNA超微颗粒的转染效率与基因产品有关。②将IL-1Ra用关节腔直接注射壳聚糖-DNA超微颗粒的方法直接转移入关节腔能一定程度上减轻骨性关节炎的进程。     

门静脉血栓机化钙化致梗阻性黄疸1例

病例男，43岁，近1个月全身皮肤黏膜黄染并瘙痒，加重10天，大便白陶土色，尿黄。脾大35年。查体：消瘦，全身皮肤黏膜黄染，下肢多处瘙痒划痕。右上腹轻压痛，可及巨脾。化验乙型肝炎表面抗原阳性。     

Accuracy of bedside ultrasound for the detection of soft tissue foreign bodies by emergency doctors

Objective: To assess the ability of emergency physicians and emergency trainees to detect soft tissue foreign bodies using typical ultrasound equipment. Methods: Following a 20 min interactive training session, emergency physicians and emergency trainees were assessed on ability to identify subcutaneous foreign bodies (wood, glass, plastic, gravel and metal) embedded in an experimental model containing both sham and real entry point incisions. In the second phase of the experiment accuracy of detection of multiple foreign bodies was assessed in a similar sonographic phantom. Results: Six emergency physicians and 14 emergency trainees performed a total of 400 individual sonographic examinations. Emergency physicians correctly identified 29 of 30 foreign bodies and returned sensitivity, specificity, positive predictive value and negative predictive value of 96.7%, 70%, 76.3% and 95.5%, respectively. Trainees correctly identified 60 of 70 foreign bodies and returned sensitivity, specificity, positive predictive value and negative predictive value of 85.7%, 82.9%, 83.3% and 85.3%. Correct identification of the number of foreign bodies present, when multiple, was low (25% physician vs 36% trainee). Conclusion: These data suggest ultrasound in the hands of emergency doctors might be useful as an initial screening tool for detection of soft tissue foreign bodies.     

Portal venous gas: detection by gray-scale and Doppler sonography in the absence of correlative findings on computed tomography

Two cases are described in which portal venous gas (PVG) was detectable by ultrasound, but the liver appeared normal on computed tomography (CT). The finding of PVG was associated with ischemic bowel in one case but was a benign finding in the other case. The gray-scale and Doppler ultrasound findings associated with PVG are described. This case report illustrates two key points. First, ultrasound may detect gas within the portal venous system when CT is negative. Second, when PVG is detected on ultrasound, urgent clinical assessment followed by contrast-enhanced CT is indicated to assess for associated intestinal ischemia.     

Bedside ultrasound for the detection of soft tissue foreign bodies: a cadaveric study

The objective of this study was to evaluate the sensitivity and specificity of bedside ultrasound, as performed by emergency physicians with typical equipment, in detecting small, soft tissue foreign bodies, using a cadaveric model. This was a prospective study, using 6 unembalmed human cadavers and 6 ultrasound-credentialed, emergency medicine residency-trained physicians as sonographers. Incisions were made in 150 total sites of the extremities and each site was randomly assigned one of five groups: wood, metal, plastic, glass, or no foreign body. All foreign bodies were 2.5 mm³ in total volume or less, no longer than 5 mm in any dimension, and inserted to a depth of up to 3 cm. Ultrasound was performed with a SonoSite TITAN^® (SonoSite, Inc., Bothell, WA) ultrasound system using a L38/10-5 broadband linear array transducer. Sonographers were blinded to the number, type, and location of foreign bodies. A total of 900 ultrasound examinations were recorded. Overall sensitivity of ultrasound for foreign body detection was 52.6% (95% confidence interval [CI] 48.9%–56.2%), and overall specificity was 47.2% (95% CI 39.9%–54.5%). Positive predictive value was 79.9% (95% CI 76.3%–83.5%), and negative predictive value was 20.0% (95% CI 16.2%–23.7%). Sensitivity for individual sonographers ranged from 40.8% to 72.3% (average 52.6% ± 13.3%), and specificity ranged from 30% to 66.7% (average 47.2% ± 15.1%). Inter-observer reliability was poor. In our model, bedside ultrasound performed by emergency physicians was neither sensitive nor specific for the presence of small soft tissue foreign bodies.     

Dual-energy computed tomography for detection of coronary artery disease

Recent technological advances in computed tomography (CT) technology have fulfilled the prerequisites for the cardiac application of dual-energy CT (DECT) imaging. By exploiting the unique characteristics of materials when exposed to two different x-ray energies, DECT holds great promise for the diagnosis and management of coronary artery disease. It allows for the assessment of myocardial perfusion to discern the hemodynamic significance of coronary disease and possesses high accuracy for the detection and characterization of coronary plaques, while facilitating reductions in radiation dose. As such, DECT enabled cardiac CT to advance beyond the mere detection of coronary stenosis expanding its role in the evaluation and management of coronary atherosclerosis.     

Study of the sensitivity and specificity of computerized tomography in the detection of calcified gallstones which appear radiolucent by conventional roentgenography

Radiolucent gallstones frequently contain significant calcium deposits. Their detection is important in the evaluation of patients for medical gallstone dissolution treatment. The sensitivity and specificity of computerized tomography (CT) in detecting calcium was studied in 20 patients with radiolucent and in 3 with radiopaque gallstones. Although the sensitivity of the CT scan was somewhat higher than that of conventional radiography — 46% versus 23%, respectively, for a calcium content of at least 4% — the CT scan was negative in 4 out of 6 patients in whom the percentage of calcium in the gallstones ranged between 10 and 100. The CT scan was specific: there were no false positive results. The results of the CT scan were not related to the amount or type of calcium salt present. The study shows that the presently used CT scan of the gallbladder is not sensitive enough to select gallstone patients for medical dissolution treatment.     

Value of helical computed tomography in the early diagnosis of esophageal foreign bodies in adults

Purpose

To investigate the relationship between early use of computed tomography (CT) and complications associated with esophageal foreign body impaction in adults.

Material and Methods

A retrospective study was performed on 120 patients (63 females, 57 males, median age 50 years) with a history of foreign bodies. All had negative findings on clinical examination. All cases underwent unenhanced helical CT, and patients with positive findings underwent esophagoscopy within 6 hours. All patients were followed up postoperatively.

Results

CT demonstrated 100% sensitivity, 92.6% specificity, 100% negative predictive value, and 97.9% positive predictive value. Esophageal foreign bodies were associated with a high incidence of complications in adults, and there was a significant difference in the incidence of complications between different durations of impaction (P < .01). In total, 37 patients presented with complications: 32 patients with grade I, 3 with grade II, 2 with grade III, and 0 with grade IV.

Conclusions

Esophageal foreign bodies were associated with a high incidence of complications in adults. CT could detect foreign bodies accurately in the early stages, and then FBs could be removed as early as possible, which may reduce the incidence of complications. Moreover, the great majority of complications were of lower grades. Thus, CT may be a useful first-line radiological tool for the early diagnosis of esophageal foreign bodies in adults.     

Intra-articular temperature: technique and reliability in an animal model

To determine if reproducible and reliable measurements of intra-articular temperature could be performed in an animal model, surface and intra-articular measurements were studied in 30 rabbits. Anterior insertion of a thermometer probe into the joint cavity was found to be a reliable method for measuring intra-articular temperature in the rabbit knee. This method yielded temperatures with less than 0.1C variation in contralateral and serial determinations. Consistent differences in intra-articular temperatures were observed between normal knees and contralateral knees in which arthritis had been experimentally induced. Measurements of surface temperature and knee intra-articular temperature by a posterior approach, however, did not give consistent or reproducible values.     

Intraperitoneal splenosis: Diagnosis by ultrasound and computed tomography

Splenosis is an unusual complication of abdominal trauma. We report a case of splenosis identified on ultrasonography (US) and computed tomography (CT). Usually it is a latent disease and an incidental finding, but it may be diagnosed by US and CT.