Significant Difference In Detection Rate Research Articles

Singular PCV2a or PCV2b infection results in apoptosis of hepatocytes in clinically affected gnotobiotic pigs

Porcine circovirus type 2 (PCV2) is clinically associated with respiratory disease, failure-to-thrive, hepatitis, and diarrhea; however, the precise pathogenesis of PCV2-associated disease and in particular its involvement in apoptosis is still controversial. The objectives of this study were (1) to determine whether PCV2 is associated with apoptosis by examining and comparing hepatic tissues from clinically affected or unaffected gnotobiotic pigs that were experimentally infected with PCV2, (2) to determine if there are differences between PCV2a and PCV2b in inducing hepatocyte apoptosis, and (3) to determine if there are differences between apoptosis detection systems. Forty-eight gnotobiotic pigs were separated into five groups based on inoculation status and development of clinical disease: (1) sham-inoculated, clinically-unaffected ( n = 4), (2) inoculated with PCV2a, clinically-unaffected ( n = 10), (3) inoculated with PCV2a, clinically-affected ( n = 6), (4) inoculated with PCV2b, clinically-unaffected, ( n = 13) and (5) inoculated with PCV2b, clinically-affected ( n = 15). Formalin-fixed, paraffin-embedded sections of liver from all pigs were analyzed for signs of apoptosis [presence of single strand DNA breaks in the nucleus by the terminal transferase dUTP nick end labeling (TUNEL) assay or presence of intra-nuclear cleaved caspase 3 (CCasp3) demonstrated by CCasp3 immunohistochemistry (IHC)]. In addition, the liver tissues were also tested for presence of cytoplasmic and intra-nuclear PCV2 antigen by an IHC assay. Specific CCasp3 and TUNEL labeling was detected in the nucleus of hepatocytes in PCV2a and PCV2b infected pigs with significantly ( P < 0.05) higher levels of apoptotic cells in clinically-affected pigs. Regardless of PCV2 subtype (PCV2a; PCV2b), there were higher levels of PCV2 antigen in clinically-affected pigs compared to clinically-unaffected pigs. There was no significant difference in detection rate of apoptotic cells between the TUNEL assay and CCasp3 IHC. When high amounts of PCV2 antigen were present, the incidence of CCasp3 and TUNEL staining also increased regardless of the PCV2 genotype. This suggests that PCV2-induced apoptosis of hepatocytes is important in the pathogenesis of PCV2-associated lesions and disease.

Evaluation of RAPID® 5 Access software for examination of capsule endoscopies and reading of the capsule by an endoscopy nurse

Since capsule endoscopy (CE) is time consuming, one possible cost-effective strategy could be the use of an expert endoscopic assistant and available software to select images. Aims were to examine the clinical utility of RAPID(®) 5 Access software and find the optimum setting mode for reading. We also evaluated whether a nurse could preview the CE video and detect significant lesions accurately. The capsule images in 14 volunteers with known mucosal injury induced by low dose aspirin and in 30 patients who were known to have a variety of significant lesions were selected. Using three setting modes of RAPID(®) 5 Access software, the detection rate and reading time for CE images by two well-trained physicians and one expert nurse were compared. There was no significant difference in detection rate among the three readers. The detection rate using Quickview RAPID(®) 5 Access was significantly higher than that using RAPID(®) Reader version 4.1. Comparison among the three modes of RAPID(®) 5 Access showed that auto mode as well as displaying a single image at 12 fps was superior in the detection rate of denuded redness, while its reading time was longer compared to the other modes. Some significant lesions were not detected by using Quickview and Quadview modes. RAPID(®) 5 Access improves diagnostic yield, reducing reading time; however, it is still unacceptable because of the diagnostic miss rate and may be useful as an ancillary reading tool. Developing further improved software and training expert assistants for reading capsule images are necessary.

Frequency of Undetected Thyroid Nodules in a Large I-131-Exposed Population Repeatedly Screened by Ultrasonography: Results from the Ukrainian–American Cohort Study of Thyroid Cancer and Other Thyroid Diseases Following the Chornobyl Accident

Imperfect detection on screening tests can lead to erroneous conclusions about the natural history of thyroid nodules following radiation exposure. Our objective was to assess in a repeatedly screened I-131-exposed population the frequency with which a thyroid nodule could be retrospectively identified on ultrasonography studies preceding the one on which it was initially detected. A cohort of over 13,000 young people exposed to fallout from Chornobyl underwent ultrasonography screening at 2-year intervals from 1998 to 2007. The study group consisted of screening examinations on which a thyroid nodule was detected following one or more prior negative examinations. In the study group there were 48 cancers and 92 benign nodules. For each of these 140 index studies a comparison set was created containing all available prior studies plus (to test for bias) negative studies from control subjects. While viewing the index study, three independent reviewers scored the comparison studies for the presence and size of a preexisting nodule. Detection rates were compared for true priors versus controls, for cancer versus benign, and for histologic subtypes of papillary carcinoma. A preexisting nodule was identified by at least one reviewer in 24.0% of the true prior versus 8.3% of the controls and by all three reviewers in 11% versus 1% (Fisher's exact test, p < 0.0001). There was no significant difference in detection rates between cancers and benign nodules (22.4% vs. 24.7%, p = 0.411). There was no correlation between time from prior to index study and change in nodule size for either malignant or benign nodules (r = 0.01, NS). There were no differences in detection rates or size among papillary cancer subtypes. Reviewers could not distinguish between true priors and controls. These findings, showing significant rates of undetected benign and malignant nodules and no evidence for rapid growth, suggest that conclusions drawn from screening studies about the frequency of late-developing, rapidly growing thyroid nodules following radiation exposure should be interpreted with caution.

Comparative Effectiveness Research in DARTNet Primary Care Practices

The Distributed Ambulatory Research in Therapeutics Network (DARTNet) is a federated network of electronic health record (EHR) data, designed as a platform for next-generation comparative effectiveness research in real-world settings. DARTNet links information from nonintegrated primary care clinics that use EHRs to deliver ambulatory care to overcome limitations with traditional observational research. Test the ability to conduct a remote, electronic point of care study in DARTNet practices by prompting clinic staff to obtain specific information during a patient encounter. Prospective survey of patients identified through queries of clinical data repositories in federated network organizations. On patient visit, survey is triggered and data are relinked to the EHR, de-identified, and copied for evaluation. Adult patients diagnosed with diabetes mellitus that scheduled a clinic visit for any reason in a 2-week period in DARTNet primary care practices. Survey on hypoglycemic events (past month) and over-the-counter and herbal supplement use. DARTNet facilitated point of care data collection triggered by an electronic prompt for additional information at a patient visit. More than one-third of respondents (33% response rate) reported either mild (45%) or severe hypoglycemic events (5%) in the month before the survey; only 3 of those were also coded using the ICD-9 (a significant difference in detection rates 37% vs. 1%). Nearly one-quarter of patients reported taking an OTC/herbal, 4% specifically for the treatment of symptoms of diabetes. Prospective data collection is feasible in DARTNet and can enable comparative effectiveness and safety research.

Detection of Vertical Root Fractures of Different Thicknesses in Endodontically Enlarged Teeth by Cone Beam Computed Tomography versus Digital Radiography

Introduction This study was performed to compare the accuracy of cone beam computed tomography (CBCT) scans and digital radiography (DR) for detecting simulated vertical root fractures (VRFs) with different thicknesses in extracted human teeth. Methods Eighty teeth were endodontically prepared and divided into 4 groups, 3 experimental and 1 control. The teeth in experimental groups were artificially fractured and fixed together with different thicknesses of 0.2 mm (0.2-mm VRF group), 0.4 mm (0.4-mm VRF group), and smaller than 0.2 mm (crack group). Teeth in control group were kept intact. Three observers evaluated the DR and CBCT images in terms of accuracy for VRF detection. Results No significant differences in detection rate were noted among the observers ( P > .5). The overall accuracy for detecting VRFs was significantly higher for CBCT scans compared with DR ( P < .001). CBCT scans were more accurate in detecting 0.2-mm VRFs (70%) and 0.4-mm VRFs (90%) as compared with DR (43.3% and 60%, respectively). Conclusions The results of this study showed that CBCT scans are effective for detecting VRFs of different thicknesses.

Does the time of day or weekday affect screening accuracy?

Workload is extensively regulated in gynecologic cytology. However, sensitive monitors of excessive workload are not available. We measured the variation in abnormal (atypical squamous cells [ASC], low-grade squamous intraepithelial lesion [LSIL], and high-grade squamous intraepithelial lesion [HSIL]) rates for 4 cytotechnologists (CTs) among different days of the week and at different times during the day while they were performing primary screening with the ThinPrep Imaging System. Three of 4 CTs detected significantly less abnormal cases on 1 day of the week than another (1 Monday, 2 Friday). Two of those CTs detected significantly fewer total abnormal cases in the afternoon than in the morning; this was strongly correlated with increased speed in the afternoon and decreased detection of ASC cases. HPV + rates for ASC cases dropped as the abnormal rate dropped. The third CT detected significantly fewer ASC cases in the morning; this was counterbalanced by an increase detection of LSIL cases, suggesting a shift in diagnostic threshold between the AM and PM. The difference in abnormal detection rates between morning and afternoon correlated with a false-negative fraction of 0.96. There are significant differences in detection rates of abnormal cases between days of the week and the morning and afternoon. Correlating abnormal rates and workload between the morning and afternoon may represent a sensitive way to detect excessive workload. Because individual CTs may have different responses to workload and no overall pattern emerged, data on their workload and performance need to be tracked individually.

Detection of HPV DNA in esophageal cancer specimens from different regions and ethnic groups: a descriptive study

BackgroundHPV has been found repeatedly in esophageal carcinoma tissues. However, reported detection rates of HPV DNA in these tumors have varied markedly. Differences in detection methods, sample types, and geographic regions of sample origin have been suggested as potential causes of this discrepancy.MethodsHPV L1 DNA and HPV genotypes were evaluated in 435 esophageal carcinoma specimens collected from four geographic regions with different ethnicities including Anyang in north China, Shantou in south China, Xinjiang in west China, and the United States. The HPV L1 fragment was detected using SPF1/GP6+ primers. HPV genotyping was performed using genotype specific PCR.ResultsTwo hundred and forty four of 435 samples (56.1%) tested positive for HPV L1. Significant differences in detection rate were observed neither among the three areas of China nor between China and the US. HPV6, 16, 18, 26, 45, 56, 57, and 58 were identified in L1 positive samples. HPV16 and 57 were the most common types in all regions, followed by HPV26 and HPV18.ConclusionsHPV infection is common in esophageal carcinoma independent of region and ethnic group of origin. Findings in this study raise the possibility that HPV is involved in esophageal carcinogenesis. Further investigation with a larger sample size over broader geographic areas may be warranted.

Comparison of Rapid Antigen Test and Real-Time Reverse Transcriptase PCR for Diagnosing Novel Swine Influenza A (H1N1)

Background Novel swine influenza (H1N1) was first identified in Mexico in April 2009. Because of its high infectivity and worldwide distribution, a rapid and efficient screening test is necessary. Here we evaluated the usefulness of a rapid antigen test currently in use, compared to realtime RT-PCR (rRT-PCR) as a screening test for detection of novel swine influenza (H1N1). Methods A total of 1,228 patients who visited Hallym University Kangdong Sacred Heart Hospital with influenza-like illness between 14 August 2009 and 30 September 2009, and were tested by both rapid antigen and rRT-PCR tests, were enrolled in this study. Results Sensitivity, specificity, predictive value of a positive test, and predictive value of a negative test for the rapid antigen test were 30.5%, 99.2%, 86.4% and 90.1%, respectively. Fifty-one (4.2%) patients were positive for both rapid antigen test and rRT-PCR, and 1,053 (85.7%) were negative for both rapid antigen test and rRT-PCR. A total of 124 (10.1%) patients showed a discrepancy between the two tests. Among them, 116 (9.4%) were only positive for rRT-PCR and 8 (0.7%) were only positive for the rapid antigen test. The latter 8 patients all showed negative H1/M2 results in rRT-PCR. There were significant differences in detection rates of the rapid antigen test between different H1 Ct (threshold cycle) interval groups and for different age groups (P ＜0.05). Conclusion Although the rapid antigen test is easy to perform and provides fast results, its limits as a screening test for detection of novel swine influenza (H1N1) due to its low sensitivity compared to rRT-PCR need to be considered in practical situations.

Diagnosis of obscure gastrointestinal hemorrhage with capsule endoscopy in combination with multiple‐detector computed tomography

To demonstrate the clinical efficacy of combination capsule endoscopy (CE) and multiple-detector computed tomography (MDCT) diagnostic imaging in the identification of gastrointestinal hemorrhages. In the present study, 123 patients with gastrointestinal hemorrhages of obscure origin (GHOO) were examined with CE in combination with MDCT. The results were compared with findings of surgical pathology. Of the 123 patients, 57.72% (71/123) of the patients exhibited positive CE findings compared with 30.08% (37/123) on MDCT alone (P < 0.01). When used in combination, 65.85% (81/123) of patients scored positively. The detection rate due to the combination of diagnostic imaging was significantly higher than that of MDCT alone (P < 0.01), but was not significantly higher than that of CE alone (P > 0.05). Integrating the two diagnostic platforms improved the diagnosis of stromal tumors, hemangioma, Crohn's disease, vascular anomaly, Meckel's diverticulum, and ancylostomiasis. There was no significant difference in the positive detection rate between CE and MDCT when confirmed by surgical pathology. The contribution of CE is critical in the diagnosis of GHOO, given the fact that there is a significant difference in the detection rate between CE and MDCT, but there is no significant difference in the rate between CE plus MDCT and CE alone.

Processing Sputum for Diagnosis and Monitoring Treatment in Tuberculosis Patients in Calabar, Nigeria

The direct smear technique of sputum examination has low sensitivity. This work was aimed at using simple and affordable procedures to improve the sensitivity of the direct smear technique suspected of having tuberculosis. The samples were then digested with 5% sodium hypochlorite and concentrated by sedimentation at room temperature and centrifugation at 3000xg for 15 minutes. Smears were made from the sediments, stained with Ziehl Neelsen stain and examined at x100 magnification. Acid fast bacilli (AFB) detection rates of 17, 27 and 33% were recorded for direct smear, sedimentation and centrifugation techniques respectively. There were significant differences in detection rates between the direct smear and concentration methods (P10 AFB/20 fields) from 2.9% to16.7% and 20.0% for direct smear, sedimentation and centrifugation respectively. Sputum concentration after digestion with sodium hypochlorite is recommended for detection of AFB in laboratories in developing countries where advances in the diagnosis of tuberculosis are yet lacking.

The effects of asymmetric vs. symmetric probability of targets following probe and irrelevant stimuli in the complex trial protocol for detection of concealed information with P300

The complex trial protocol (CTP, [J.P. Rosenfeld, E. Labkovsky, M. Winograd, M.A. Lui, C. Vandenboom & E. Chedid (2008), The complex trial protocol (CTP): a new, countermeasure-resistant, accurate P300-based method for detection of concealed information. Psychophysiology, 45, 906–919.]) is a sensitive, new, countermeasure-resistant, P300-based concealed information protocol in which a first stimulus (Probe or Irrelevant) is followed after about 1.4–1.8 s by a Target or Non-Target second stimulus within one trial. It has been previously run with a potentially confounding asymmetric conditional probability of Targets following Probes vs. Irrelevants. This present study compared asymmetric vs. symmetric conditional probability groups and found no significant differences in detection rates or Probe-minus-Irrelevant P300 differences between groups. Group differences were seen in error rates and reaction times (RT) to second stimuli. These differences were, however, not diagnostic for deception vs. truth-telling, and were attributable to response perseveration.

Does Transrectal Ultrasound Probe Configuration Really Matter? End Fire Versus Side Fire Probe Prostate Cancer Detection Rates

We compared prostate cancer detection rates for the 2 most commonly used transrectal ultrasound prostate biopsy probes, end fire and side fire, to determine whether the probe configuration affects detection rates. We evaluated 2,674 patients who underwent initial prostate biopsy between 2000 and 2008 with respect to prostate specific antigen, biopsy technique and pathological findings. Patients were divided into 1,124 in whom biopsies were performed with an end fire probe and 1,550 in whom biopsies were performed with a side fire probe. There was a significant difference in the overall cancer detection rate in the end vs side fire arms (45.8% vs 38.5%, p <0.001). In the subsets of patients with prostate specific antigen greater than 4 to 10 ng/ml or less and greater than 10 ng/ml a significant difference persisted (46.4% vs 38.9% and 61.7% vs 49.1%, p <0.004 and <0.015, respectively). There was also a significant difference in detection rates between probes in those who underwent 8 to 19 biopsy cores (p <0.009). Biopsies of greater than 20 cores failed to attain statistical significance (p >0.105). We also found that prostate volume, patient age, prostate specific antigen and hypoechoic findings were independent variables for predicting cancer detection on multivariate analysis (p <0.001). The type of probe significantly affects the overall prostate cancer detection rate, particularly in patients with prostate specific antigen greater than 4 ng/ml and/or nonsaturation (8 to 19 cores) prostate biopsy. This may be because the end fire probe allows better mechanical sampling of the lateral and apical regions of the peripheral zone, where cancer is most likely to reside. We set the stage for a randomized, controlled trial to confirm our observations.

COMPARISON OF ENDOSCOPIC DETECTION RATE OF EARLY GASTRIC CANCER AND GASTRIC ADENOMA USING TRANSNASAL EGD WITH THAT OF TRANSORAL EGD

Background: To investigate the influence of the reduced image quality of transnasal esophagogastroduodenoscopy (EGD) with the ultrathin endoscope (transnasal EGD) on endoscopic diagnoses, we compared the detection rate (DR) of early gastric cancer and gastric adenoma by transnasal EGD with that of transoral EGD using a standard endoscope.Methods: Transnasal EGD was carried out in 2791 examinations for the purposes of screening or other reasons. Controls were examined by transoral EGD and numbered 3591 examinations. The transnasal endoscope used was an EG530N. Lesions graded C‐3 or higher by Kimura‐Takemoto's classification were regarded as endoscopic atrophy.Results: (i) DR in all subjects and those with atrophy were not different between transnasal and transoral EGD. (ii) Multivariate analysis of DR in subjects with atrophy was carried out using five variables: gender, age, purposes of endoscopy, endoscopic insertion route and the four endoscopists. DR was significantly higher in males or subjects ≥60 years. No difference was noted between the endoscopic insertion routes (transnasal vs transoral). (iii) The subjects analyzed in (ii) were divided into the transnasal and transoral groups, and multivariate analysis of DR was carried out using four variables. DR was not different among the endoscopists in the transoral group. However, in the transnasal group, DR increased as the years of endoscopic experience was prolonged.Conclusions: Multivariate analysis detected no significant difference in DR between transnasal and transoral EGD. However, a significant difference in DR by transnasal EGD among the endoscopists is detected. Transnasal EGD should be carefully carried out by experienced endoscopists.

Comparison of axial, coronal, and primary 3D review in MDCT colonography for the detection of small polyps: A phantom study

Purpose The purpose of this phantom study is to compare the influence of the reading technique (axial images alone in comparison to 3D endoluminal, coronal, and combined 2D/3D review methods) on the sensitivity and inter-reader variability with MDCT colonography for the detection of small colonic polyps. Methods An anthropomorphic pig colon phantom with 75 randomly distributed simulated small polyps of 2–8 mm size, was distended with air and scanned in a water phantom using multidetector-row CT with 4 mm × 1 mm collimation. Three radiologists rated the presence of polyps on a five-point scale. Performance with axial sections alone was compared to the performance with coronal sections, virtual endoscopy (VE), and a combined 2D/3D approach. We calculated sensitivities for polyp detection and used ROC analysis for data evaluation. Results There was no significant difference between the mean area under the curve ( A z) for axial images and VE ( A z = 0.934 versus 0.932), whereas coronal images were significantly inferior ( A z = 0.876) to both. The combined 2D/3D approach yielded the best results, with an A z of 0.99. Differences in sensitivity between individual readers were significant in axial images (sensitivity, 75–93%, p = 0.001) and coronal images (sensitivity, 69–80%, p = 0.028), but became non-significant with VE (83–88%, p = 0.144) and the combined 2D/3D approach (95–97%, p = 0.288). Conclusion Evaluation of axial sections alone leads to significant differences in detection rates between individual observers. A combined 2D/3D evaluation improves sensitivities for polyp detection and reduces inter-individual differences to an insignificant level.

The influence of prostate volume on prostate cancer detection using a combined approach of contrast‐enhanced ultrasonography‐targeted and systematic grey‐scale biopsy

To evaluate the influence of prostate volume (PV) on the detection of prostate cancer using a combined approach of contrast-enhanced ultrasonography (CEUS) and grey-scale US-guided systematic biopsy (SB). We evaluated 345 patients with prostate cancer and a total prostate-specific antigen (PSA) level of >/= 1.32 ng/mL (1.32-35.3, mean 6.6). Biopsies were taken by two independent examiners; one took five CEUS (Doppler) targeted biopsies of hypervascular regions in the peripheral zone, and subsequently the other took 10 systematic prostate biopsies. We assessed the cancer detection rates for the five different subgroups of prostate volumes, i.e. <20, 20-30, 30-40, 40-50 and > 50 mL. Each technique, SB and CEUS, detected 73.4% and 77.1% of all detected cancers, respectively, but there were statistically significant differences in detection rate only in small glands. Only 69.0% and 70.4% of all cancers were detected by SB in glands of <20 and 20-30 mL, respectively, whereas 88.1% and 80.8% were detected by CEUS. The prostate cancer detection rate for CEUS was significantly higher in prostates of <30 mL (48.1% of the study population) than for SB. Therefore the combined approach of CEUS and SB allows improved cancer detection in patients with small glands and low total PSA values.

Identification of occult prostate malignancy using a stereotactic transperineal prostate biopsy technique

15520 Background: This study investigates the detection rate of non-palpable, isoechoic occult prostate malignancy using a stereotactic transperineal prostate biopsy (STPB) technique in patients with previously negative transrectal ultrasound-guided prostate biopsy. Methods: 327 consecutive patients with continued rising total prostate specific antigen (PSA) with a minimum of 1 prior benign transrectal prostate biopsy (range 1–8), underwent STPB at a single out-patient institution between 05/2004 and 11/2006. Median patient age, total PSA and prostate volume and number of specimens obtained were 62 years, 8.3 ng/ml, 46.1 cm3 and 40 specimens, respectively. Similar to a prostate brachytherapy procedure, the prostate was positioned on the implant grid. Specimens were obtained according to x, y, and z coordinates from eight equal octants with pathology reported accordingly. A greater number of specimens were obtained from the apical half than the basilar half of the prostate; this was attributed to smaller glands in which the apical specimens sufficiently sampled the anterior curvature of the gland. Results: STPB yielded adenocarcinoma in 125/327 (38%) patients. The number of biopsy cores obtained per patient approximated the prostate gland volume in cm3. Multivariate analysis (paired samples t-tests) demonstrated there was a significant difference in detection rates with the apex having a higher incidence of malignancy than the base of the prostate gland (p=.000). Furthermore, the anterior apex harbored significantly more adenocarcinoma when compared to the posterior apex (p=.026) ( Table 1 ). Conclusions: STPB is efficacious for diagnosis of non-palpable, isoechoic occult prostate malignancy. A possible explanation for the significant finding in this study that occult malignancies occupy a higher percentage of apical biopsies using STPB may be related to difficulty and limitations of apical sampling using a standard transrectal biopsy approach. [Table: see text] No significant financial relationships to disclose.

MDCT Angiography for Detection and Quantification of Small Intracranial Arteries: Comparison with Conventional Catheter Angiography

MDCT angiography can serve as an alternative to digital subtraction catheter angiography for the study of large and medium-sized arteries. Our goal was to achieve a better understanding of the capabilities and limitations of both MDCT angiography and digital subtraction angiography in the evaluation of intracranial arteries with an average diameter of 1.5 mm or less. A blinded retrospective analysis of the presence and size of nine small cerebral arteries on both 2D and 3D CT angiography (CTA) was conducted with 27 patients who had normal findings at CTA and digital subtraction angiography. Scans of 455 arterial segments obtained with either 4-MDCT or 16-MDCT were examined by two independent blinded reviewers. The sensitivity and specificity of CTA for each vessel were established. A chi-square test was used to determine interoperator reliability. The smallest arterial size reliably detected with MDCT angiography with our imaging and postprocessing protocol was 0.7 mm versus 0.4 mm for digital subtraction angiography. Interoperator reliability for vessel identification with MDCT angiography was 97% without significant differences in detection rates between 4-MDCT and 16-MDCT. Two-dimensional CTA depicted more than 90% of arteries studied but only 63% of anterior choroidal arteries and 27% of recurrent arteries of Heubner. There were no significant differences in mean arterial sizes measured with 2D CTA versus digital subtraction angiography for six of nine arteries. In six of nine arterial segments with a mean diameter of 1 mm or less, fewer arterial segments were visualized on 3D CTA than on 2D CTA. Except for the recurrent artery of Heubner and the anterior choroidal artery, MDCT angiography depicted 90% or more of all examined small intracranial arteries detected with digital subtraction angiography. The mean sensitivity was 0.91, and the mean specificity was 0.7.

The evaluation of clinical and treponemal antibody in cerebrospinal fluid of infants with congenital syphilis

目的 总结先天梅毒患儿在临床表现和血清、脑脊液梅毒抗体方面的特点.方法对40例先天梅毒患儿进行了临床特点和血清、脑脊液梅毒抗体的分析.结果 40例先天梅毒患儿中出现皮疹的有14例(35%),有骨损害表现的6例(15%);由于母亲患梅毒而就诊的16例(40%),40例先天梅毒患儿中,快速血浆反应素试验(RPR)阳性33例(82.5%),阳性血清RPR滴度介于1∶1～1∶64之间,2例RPR异常增高,滴度为1∶128.患儿脑脊液常规检查显示,45%淋巴细胞增高,50%蛋白增多,22.5%的患儿脑脊液存在梅毒抗体.性病研究实验室试验(VDRL)和梅系螺旋体被动颗粒凝集试验(TPPA)相比,检出率差异有显著意义(P＜0.05). 结论必须重视先天梅毒患儿神经梅毒的发生,脑脊液梅毒抗体检测对正确评价病情和指导治疗有重要意义。

Computer-aided Lung Nodule Detection in CT: Results of Large-Scale Observer Test 1

The objective is to study the incremental effects of using a computer-aided lung nodule detection (CAD) system on the performance of a large pool of observers. A set of eight thin-section computed tomographic data sets with limited longitudinal coverage, containing a total of 22 lung nodules, was analyzed by using the automated nodule detection system. When applied to all eight cases, the CAD system alone achieved a detection rate of 86.4%, with 2.64 false-positive results per case. This study included 202 observers at a national radiology meeting: 39 thoracic radiologists, 95 non-thoracic radiologists, and 68 non-radiologists. Each participant read from one to eight cases in random order, first without and then with CAD system output available. Observer performance in nodule detection was measured before and after CAD was made available. Differences in performance of groups of observers before and after CAD were tabulated by mean, median, and SD in detection rate and number of false-positive results and tested by using nonparametric methods. In an analysis involving only the first randomly selected case read by all 202 participants, there were statistically significant increases in nodule detection rates and numbers of false-positive results for all types of observers. There was a significant difference in detection rates between radiologists and non-radiologists before CAD, but after CAD, there was no significant difference in detection rates between these observer types. In a second analysis involving 13 participants who read all eight cases, mean detection rates were 64.0% before CAD and 81.9% after CAD. Mean numbers of false-positive results were 0.144 per case before CAD and 0.173 after CAD. In a large observer study, use of a CAD system for nodule detection resulted in an incremental increase in detection rate, but also led to an increase in number of false-positive results. Also, CAD appears to be an equalizer of detection rates between observers of different levels of experience.

Comparison of two culture media and three sampling techniques for sensitive and rapid screening of vaginal colonization by group B streptococcus in pregnant women.

The Centers for Disease Control and Prevention (CDC) recommend universal screening of all pregnant women between 35 and 37 weeks of gestation for group B streptococci (GBS) by use of a selective broth medium. Recent reports suggest that Granada medium can be used for rapid and direct visual identification of GBS colonies. However, studies comparing the Granada medium method to the selective broth method are few, and while some report comparable sensitivities, others have found significant differences in detection rates between the two methods. This prospective study compared a method using Granada agar to a Todd-Hewitt broth method with subculture to blood agar in order to determine which GBS detection method is more sensitive and less labor-intensive and has a more rapid turnaround time. Detection rates for three sampling techniques (rectovaginal, vaginal only, and cervical only) were also compared. Consecutive specimens for GBS screening received over a 6-month period from 1,635 pregnant women were included. Overall, GBS was detected in 390 (23.8%) women. The Granada medium gave positive results for 348 of these women, and the selective broth gave positive results for 385, indicating sensitivities of 89.2% for the Granada medium and 98.7% for the selective broth. These findings show that the Granada medium method is less sensitive than the selective broth method and should not replace it as the only method for screening pregnant women for GBS. However, the Granada medium method reduced detection time to 1 day and also reduced the use of ancillary tests in approximately 90% of positive cases. Additionally, no significant differences were noted in the detection rates with rectovaginal, vaginal, and cervical specimens.