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PubMed2005

Optical techniques for the endoscopic detection of dysplastic colonic lesions.

PURPOSE OF REVIEW: Within the past decade, advances in biomedical optics have been applied to overcome sensitivity and specificity limitations in conventional diagnostic endoscopy for detecting dysplasia and noninvasive cancer. This review presents the current status of emerging optical techniques that rely on the complex interaction of light with tissue, and their possible roles in detection, mapping, staging, and therapy of dysplasia. RECENT FINDINGS: Progress in endoscopic autofluorescence imaging has been dominated by efforts to enhance the detection of dysplasia with tumor-localizing prodrugs. Raman and light-scattering spectroscopy have had very limited reporting for the colon. Endoscopic optical coherence tomography has now acquired real-time Doppler capabilities, and rudimentary endoscopic criteria for hyperplastic and adenomatous polyps have been described. Narrow-band imaging endoscopy awaits large-scale testing in the colon. The greatest activity has been reported for chromoendoscopy. Although contradictory results of diagnostic accuracy must be clarified and optimal methodologies are yet to be outlined, magnifying endoscopy has resuscitated chromoendoscopy. Single-cell subsurface imaging has been achieved with confocal fluorescence microendoscopy on excised tissues and now the first clinical experience has been reported. New and exciting research using highly specific and bright tumor-targeted fluorescence contrast agents is thrusting diagnostic endoscopy into a new era of "molecular endoscopy." SUMMARY: Most studies reported to date have mainly focused on refining existing prototype instruments or continue on a basic research level, with the ultimate goal of improving sensitivity and specificity for colonic dysplasia, compared with the gold standard of histopathology. It is more than likely that the future diagnostic role of these evolving technologies will involve the combination of two or more complementary technologies, and "molecular targeting" approaches will be crucial for earliest detection. However, despite innovative applications and refinement of the existing ones, large, controlled, prospective multicenter trials are still anxiously awaited by the practicing endoscopist to evaluate the diagnostic role and cost-effectiveness of these emerging technologies in the gastroenterology clinic.

Chromogenic Compounds↗
PubMed1999

Likelihood-based diagnostics for influential individuals in non-linear mixed effects model selection.

PURPOSE: Data from single individuals, or a small group of subjects may influence non-linear mixed effects model selection. Diagnostics routinely applied in model building may identify such individuals, but these methods are not specifically designed for that purpose and are, therefore, not optimal. We describe two likelihood-based diagnostics for identifying individuals that can influence the choice between two competing models. METHODS: One method is based on a jackknife of the raw data on the individual level and refitting the model to each new data set. The second method is a calculation which utilises the contribution each individual make to the objective function values under each of the two models. The two methods were applied to model selection during analysis of a real data set. RESULTS: The agreement between the methods was high. Individuals for whom there was a discrepancy between the methods tended to be those for which neither of the contending models described the data appropriately. Both methods identified individuals that influenced the model selection. CONCLUSIONS: Two objective, specific and quantitative methods for identifying influential individuals in nonlinear mixed effects model selection have been presented. One of the methods doesn't require additional model fitting and is therefore particularly attractive.

Age Factors↗
PubMed2000

Analysis of false-negative diagnoses on endoscopic brush cytology of biliary and pancreatic duct strictures: the experience at 2 university hospitals.

CONTEXT: Endoscopic brush cytology is a valuable technique for the diagnosis of pancreatobiliary malignancy. Despite its widespread use, the sensitivity of this method has been reported as approximately 50%. The specificity is usually higher than 95%. Few reports have systematically analyzed the reasons for this relatively low sensitivity. OBJECTIVES: To determine the rate and reasons for false-negative diagnoses in endoscopic brushing cytology of biliary and pancreatic ducts based on the results of sensitivity, specificity, accuracy, and positive and negative predictive values. DESIGN: Retrospective analysis of laboratory data and slide review of false-negative cases. SETTING: Two tertiary care state university hospitals. PATIENTS: A total of 183 pancreatobiliary brushing specimens obtained from patients undergoing endoscopic retrograde cholangiopancreatography for biliary or pancreatic duct disease for a 4- to 5-year period. INTERVENTION: Endoscopic retrograde cholangiopancreatography brushings. MAIN OUTCOME MEASURES: Determination of sensitivity, specificity, accuracy, and positive and negative predictive values. Analysis of false-negative results. RESULTS: The sensitivity, specificity, accuracy, and positive and negative predictive values, overall, were 48%, 98%, 79%, 92%, and 76%, respectively. Sampling error was a major cause of false-negative diagnoses (67%), followed by interpretive (17%) and technical errors (17%). CONCLUSIONS: Improvements in sensitivity and diagnostic accuracy for cancer of the pancreatobiliary tract can be achieved by optimizing slide preparatory techniques. Also, enhancement of the cytologist's diagnostic skills enables the identification of the morphologic features of premalignant lesions. Repeat brushings are indicated for suspicious or negative results not consistent with the clinical or radiologic findings.

Bile Duct Diseases↗
PubMedDate not supplied

[Principles of organizational activities of centralized diagnostic services].

The main provision of a stage-type organization of the diagnostic-assistance in regions as well as the key requirements applicable to optimizing the laboratory instrument structure, as related with performing various diagnostic tests, were studied; this ensured an essential increase in the annual average utilization per one laboratory instrument. The training of doctors, engineers and labor stimulation system were in the focus of attention.

Diagnostic Services↗
PubMed2003

Developing a comprehensive diagnostic and interventional nephrology program at an academic center.

Procedure-related delays in the treatment of patients with renal disease can be minimized and nephrology care can be delivered more efficiently by a nephrologist trained in nephrology-related procedures. Referrals to a radiologist for renal ultrasound and biopsy, to a surgeon for dialysis access placement, and to an interventional radiologist for dialysis catheter placement and vascular access procedures are time consuming and inconvenient to patients with renal disease. Moreover, such an approach may result in delays in the availability of critical diagnostic information and a break in the continuity of care. In an effort to optimize the care of nephrology patients, we developed a diagnostic and interventional nephrology (DIN) program that effectively deals with nephrology-related procedures in a timely manner. At present, some of the commonly performed nephrology-related procedures at our center include diagnostic ultrasonography, ultrasound-guided renal biopsy, peritoneal dialysis access procedures, permanent tunneled hemodialysis catheter placement, and endovascular procedures for arteriovenous dialysis access dysfunction. To date, we have performed 893 procedures during a period of 2 years. This article describes our approach and the tools required to develop a DIN program at an academic medical center.

Academic Medical Centers↗
PubMed2003

Determining cost-effectiveness and cost component of three malaria diagnostic models being used in remote non-microscope areas.

This cross-sectional experimental study developed a methodology to analyze the cost-effectiveness of three malaria diagnostic models: microscopy; on-site OptiMAL; and on-site Immunochromatographic Test (on-site ICT), used in remote non-microscope areas in Thailand, from both a public provider and patient perspective. The study covered six areas in two highly malaria-endemic areas of provinces located along the Thai-Myanmar border. The study was conducted between April and October 2000, by purposively recruiting 436 malaria suspected cases attending mobile malaria clinics. Each patient was randomly selected to receive service via the three diagnostic models; their accuracy was 95.17%, 94.48% and 89.04%, respectively. In addition, their true positive rates for all malaria species were 76.19%, 82.61% and 73.83%; for falciparum malaria 85.71%, 80.95% and 80.00%, and for vivax malaria 57.14%, 100% and 50%, respectively, with the parasitemia ranging from 80 to 58,240 microl of blood. Consequently, their costs were determined by dividing into provider and consumer costs, which were consequently classified into internal and external costs. The internal costs were the costs of the public providers, whereas the external costs were those incurred by the patients. The aggregate costs of these three models were 58,500.35, 36,685.91, and 40,714.01 Baht, respectively, or 339.53, 234.39, and 243.93, in terms of unit costs per actual case. In the case of microscopy, if all suspected malaria cases incurred forgone opportunity costs of waiting for treatment, the aggregate cost and unit cost per actual case were up to 188,110.89 and 944.03 Baht, respectively. Accordingly, the cost-effectiveness for all malaria species, using their true positive rates as the effectiveness indicator, was 446.75, 282.40, and 343.56 respectively, whereas for falciparum malaria it was 394.80, 289.37 and 304.91, and for vivax malaria 595.67, 234.39 and 487.86, respectively. This study revealed that the on-site OptiMAL was the most cost-effective. It could be used to supplement or even replace microscopy for this criteria in general. This study would be of benefit to malaria control program policy makers to consider using RDT technology to supplement microscopy in remote non-microscope areas.

Chromatography↗
PubMed2003

How helpful is pneumatic otoscopy in improving diagnostic accuracy?

BACKGROUND: Pneumatic otoscopy is believed to be helpful in optimally assessing the presence or absence of middle ear effusion (MEE). Although expert clinicians teach the importance of this diagnostic skill to trainees, evidence exists that many pediatric providers do not typically perform pneumatic otoscopy. OBJECTIVE: To determine if the otoscopic accuracy within a group of clinicians improves with the pneumatic assessment when compared with the static assessment using videotaped otoendoscopic examinations (VOEs). METHODS: Residents and faculty from 2 pediatric training programs served as subjects. All viewed a set of 50 video otoscopic examinations of tympanic membranes (TMs) from a validated VOE developed previously for training purposes. The video displays each TM in a static presentation and then in a pneumatic (mobile) presentation, followed by a final static presentation. Each subject first viewed the initial static presentation of each TM and responded "yes/no" to the presence of MEE, and then viewed the pneumatic presentation of the same TM and again responded "yes/no" to the presence of MEE. We compared the accuracy of assessment for both the static and the pneumatic tests. RESULTS: Thirty-four pediatric residents and 6 clinical faculty participated. Accuracy (percent of total test items correct) on the pneumatic test was uniformly greater than accuracy on the static test. The mean absolute improvement in the accuracy from the static test (61%) to the pneumatic test (76%) was 15% (95% confidence interval [CI] = 12%-18%). The mean relative improvement in accuracy from the static test to the pneumatic test was 26% (95% CI = 19%-32%). Higher accuracy on the VOE was associated with greater absolute (r = 0.57) and greater relative (r = 0.47) improvement. The mean relative improvement in sensitivity and specificity from static viewing to pneumatic viewing was 24% (95% CI = 15%-33%) and 42% (95% CI = 27%-58%), respectively. CONCLUSIONS: Using a video otoendoscopic test, we found that accurate identification of both the presence and the absence of MEE improved after pneumatic assessment of TM mobility. Providers who were more accurate at otoscopy, defined by higher video total test scores, benefited more from the pneumatic component than providers with lower scores.

Acoustic Impedance Tests↗
PubMed2004

The impact of echography on evaluation and management of posterior segment disorders.

PURPOSE: To investigate the impact on patient management of posterior segment echographic evaluation at an academic institution. DESIGN: Retrospective, noncomparative, consecutive case series. METHODS: Records were reviewed of all patients evaluated for the first time with ocular echography for posterior segment evaluation at Bascom Palmer Eye Institute between September 2000 and August 2001. Patients with prior posterior segment echography, intraocular tumors, or suspected optic nerve or orbital disease were excluded. An "impactful" echographic evaluation was defined as an evaluation that confirmed the diagnosis and management plan. A "pivotal" evaluation was defined as an evaluation that either (1) made or subclassified the diagnosis or (2) established or changed the management plan or both. Main outcome measures include proportions of impactful and pivotal echographic evaluations and factors associated with pivotal evaluations. RESULTS: The study included 154 eyes of 143 patients. The requesting physician was a retina fellowship-trained faculty member in 55 cases (36%), a nonretina faculty member in 22 (14%), a fellow in 9 (6%), and a resident in 68 (44%). Reasons for obtaining echography included evaluation for retinal tear or detachment in 83 eyes (54%), evaluation for posterior segment disease (for example, before cataract extraction) in 40 (26%), evaluation for endophthalmitis in 10 (7%), evaluation for intraocular foreign body in 8 (5%), characterization of choroidal detachment in 4 (2%), and other in 9 (6%). Echography confirmed the suspected diagnosis and pre-echography management plan in 128 eyes (83%). Echography made or subclassified the diagnosis in 20 eyes (13%) and established or changed the management plan in 12 eyes (8%). Accounting for definitional overlaps, echography was pivotal in 22 eyes (14%). Significant predictors of a pivotal evaluation or an evaluation that affected the management plan include a retina faculty member as the requesting physician (P =.003), lack of a management plan before echography (P <.001), and certain reasons for obtaining echography (for example, to rule out retinal tear or detachment and to rule out intraocular foreign body; P =.032). The final clinical or pathologic diagnosis confirmed the echographic diagnosis in 148 eyes (96%). CONCLUSIONS: Posterior segment echography may be a very useful diagnostic tool. Its value may be optimized in certain subsets of patients. Considerations such as these may contribute to more cost-effective allocation of resources.

Adolescent↗
PubMedDate not supplied

Characterization and optimization of bovine Echinococcus granulosus cyst fluid to be used in immunodiagnosis of hydatid disease by ELISA.

The aim of this work was to assess the influence in the diagnostic value for human hydatid disease of the composition of bovine hydatid cyst fluid (BHCF) obtained from fertile (FC) and non-fertile cysts (NFC). Eight batches from FC and 5 from NFC were prepared and analysed with respect to chemical composition: total protein, host-derived protein, carbohydrate and lipid contents. No differences were observed in the first two parameters but carbohydrate and lipid contents were shown to be higher in batches from FC than in those from NFC. Bands of 38 and 116 kD in SDS-PAGE profiles were observed to be present in BHCF from FC only. Two pools were prepared from BHCF batches obtained from FC (PFC) and NFC (PNFC), respectively. Antigen recognition patterns were analysed by immunoblot. Physicochemical conditions for adsorption of antigens to the polystyrene surface (ELISA plates) were optimized. The diagnostic value of both types of BHCF as well as the diagnostic relevance of oxidation of their carbohydrate moieties with periodate were assessed by ELISA using 42 serum samples from hydatid patients, 41 from patients with other disorders, and 15 from healthy donors. Reactivity of all sera against native antigen were tested with and without free phosphorylcholine. The best diagnostic efficiency was observed using BHCF from periodate-treated PFC using glycine buffer with strong ionic strength to coat ELISA plates.

Animals↗
PubMed2000

A spreadsheet for the calculation of comprehensive statistics for the assessment of diagnostic tests and inter-rater agreement.

While advances in statistical methods allow greater insight into the characteristics of diagnostic tests and of raters, researchers frequently rely on incomplete or inappropriate indices of performance. Lack of available computer software is probably an important barrier to optimal use of data collected to evaluate diagnostic tests and agreement between raters. A spreadsheet has been designed to provide comprehensive statistics for the assessment of diagnostic tests and inter-rater reliability when these investigations yield data that can be summarized in a 2x2 table. As well as a wide range of indices of test or rater performance, confidence intervals for these quantities are also calculated by the spreadsheet.

Confidence Intervals↗
PubMed2005

The evaluation of rectal bleeding in adults. A cost-effectiveness analysis comparing four diagnostic strategies.

BACKGROUND: Though primary care patients commonly present with rectal bleeding, the optimal evaluation strategy remains unknown. OBJECTIVE: To compare the cost-effectiveness of four diagnostic strategies in the evaluation of rectal bleeding. DESIGN: Cost-effectiveness analysis using a Markov decision model. DATA SOURCES: Systematic review of the literature, Medicare reimbursement data, Surveillance, Epidemiology, and End Results (SEER) Cancer Registry. TARGET POPULATION: Patients over age 40 with otherwise asymptomatic rectal bleeding. TIME HORIZON: The patient's lifetime. PERSPECTIVE: Modified societal perspective. INTERVENTIONS: Watchful waiting, flexible sigmoidoscopy, flexible sigmoidoscopy followed by air contrast barium enema (FS+ACBE), and colonoscopy. OUTCOME MEASURES: Incremental cost-effectiveness ratio. RESULTS OF BASE-CASE ANALYSIS: The incremental cost-effectiveness ratio for colonoscopy compared with flexible sigmoidoscopy was 5,480 dollars per quality-adjusted year of life saved (QALY). Watchful waiting and FS+ACBE were more expensive and less effective than colonoscopy. RESULTS OF SENSITIVITY ANALYSES: The cost of colonoscopy was reduced to 1,686 dollars per QALY when age at entry was changed to 45. Watchful waiting became the least expensive strategy when community procedure charges replaced Medicare costs, when age at entry was maximized to 80, or when the prevalence of polyps was lowered to 7%, but the remaining strategies provided greater life expectancy at relatively low cost. The strategy of FS+ACBE remained more expensive and less effective in all analyses. In the remaining sensitivity analyses, the incremental cost-effectiveness of colonoscopy compared with flexible sigmoidoscopy never rose above 34,000 dollars. CONCLUSIONS: Colonoscopy is a cost-effective method to evaluate otherwise asymptomatic rectal bleeding, with a low cost per QALY compared to other strategies.

Adult↗
PubMed1999

[Application and possibilities of digital radiography demonstrated on a skull radiograph].

The application of digital radiography has not been used widely in veterinary medicine. This paper gives an overview of the possibilities in post processing of digital radiographs for imaging a nasal fracture on a right lateral skull radiograph of a two years old German Shepherd. The following algorithms of the digital ADC (Agfa Diagnostic Center)--system were used: edge-contrast, latitude reduction, noise reduction, window-levelling and MUSI-contrast (MUlti Scale Image Contrast). MUSI-contrast is a recently developed algorithm by Agfa, which improves the recognition of fine details in all scales. These parameters will be explained individually and the use is demonstrated with the skull radiographs. It shows that only a coordinate parameter setting will lead to an optimal image. The option of filtering diagnostic information in using digital post processing represents a clear step forward and reduces the number of repeat shots.

Algorithms↗
PubMed2005

Diagnosis and treatment of noncardiac chest pain.

Chest pain is common: one in four of the population have an episode annually. Of those who present to hospital, nearly two-thirds have noncardiac chest pain. More than half of these cases might have gastroesophageal reflux disease. Opinion differs over what is the most appropriate application of current investigatory methods. Evidence suggests that, once cardiac disease is ruled unlikely, empiric use of a proton pump inhibitor is an option; if acid suppression fails, detailed investigations as clinically indicated can be considered. A range of esophageal investigations is available, including 24-hour or 48-hour esophageal pH testing and esophageal manometry, as well as provocative tests, but there is no consensus as to which methods are the most useful. Psychiatric evaluation is not routine, but psychiatric or psychological disorders are common. Musculoskeletal disorders are also common, but are frequently overlooked. It is possible to subject patients to a comprehensive set of investigations before empiric therapy, but recent studies have failed to demonstrate an improved outcome using this exhaustive approach. A new tactic is required, with less attention spent on absolute diagnostic accuracy and more emphasis on optimizing the long-term clinical outcome in patients with noncardiac chest pain. It is possible that the targeted use of multiple drug trials in a policy of 'therapy as investigation' might be a superior methodology.

Chest Pain↗
PubMed2002

Optimal post-contrast timing of breast MR image acquisition for architectural feature analysis.

PURPOSE: To define a post-contrast imaging time span during which diagnostic accuracy of breast magnetic resonance (MR) architectural feature analysis is maintained. MATERIALS AND METHODS: Seventy-five patients with mammographically-visible or palpable findings underwent MR examination. Three sequential post-contrast, fat-saturated, three-dimensional gradient-echo imaging runs were acquired spanning 0-90, 90-180, and 180-270 seconds after contrast injection. Five readers independently predicted the malignant potential of the MR abnormalities. RESULTS: Receiver-operator characteristics (ROC) curves were our primary measure of diagnostic accuracy. The accuracy of four readers was unchanged over the three post-contrast runs. One reader was slightly more accurate using the second and third runs than using the first. CONCLUSION: For most readers, a single post-contrast run performed at any point during the first four minutes and 30 seconds following injection should yield an equivalent diagnostic accuracy. If any time period is less optimal, it is that of our first run, performed between 0-90 seconds after contrast injection.

Adult↗
PubMed2002

Rectal biopsy: what is the optimal procedure?

Rectal suction biopsy (RSB) is a well-known diagnostic procedure for disorders of bowel motility such as Hirschsprung's disease (HD). However, there are few reports about the optimal method of obtaining rectal tissue. We introduce a new technique using Gruenwald's nasal cutting forceps (NCF). From 1986 to 1999, we performed 130 sets of rectal biopsies in patients suspected of having HD. In group I (1986 to 1994), 68 sets of three-site biopsies (2, 3, and 5 cm above the dentate line) were performed using a conventional blind RSB technique. In group II (1995 to 1999), 62 sets of one-site biopsies (2 cm above the dentate line) were performed using Gruenwald's NCF after anal dilatation during general anesthesia. Hematoxylin-eosin staining and acetylcholinesterase histochemistry were used to examine all specimens. Biopsy specimens in group II (4.39 +/- 1.07 mm(2)) were larger than in group I (1.59 +/- 0.39 mm(2)) ( P < 0.01). In 18 cases (26 %) in group I, normal and HD bowel could not be differentiated because the specimens were too small to detect ganglion cells (i.e., only lamina propria [9 cases] or a small area of submucosa [9 cases] was present). These cases required repeat biopsy. All cases of HD diagnosed in group I (n = 20) were based on the findings of biopsies taken at 2 cm; biopsies from 3 and 5 cm did not provide additional information. There were 2 cases of post-biopsy hemorrhage in group I. In group II, 18 subjects were diagnosed with HD and 39 were confirmed to have normal bowel. There were no complications and repeating the biopsy was unnecessary. Three cases of hypoganglionosis (1 in group I and 2 in group II) were missed because the myenteric plexus abnormalities could not be detected by RSB. Intestinal neuronal dysplasia (IND) was diagnosed in 5 cases (2 in group I by repeat full-thickness biopsy and 3 in group II by rectal biopsy). We conclude that our new technique is advantageous and safe to differentiate between normal bowel, HD, and even IND on the basis of a single biopsy taken 2 cm above the dentate line. The biopsy can be taken under direct vision and is histopathologically accurate.

Adolescent↗
PubMed2005

Optimal bedside urinalysis for the detection of proteinuria in hypertensive pregnancy: a study of diagnostic accuracy.

OBJECTIVE: To compare semi-quantitative visual and automated methods of urine testing with fully quantitative point of care urinalysis for the detection of significant proteinuria (0.3 g/24 hours) in pregnancy complicated by hypertension. DESIGN: A prospective comparative study. SETTING: A large teaching maternity hospital. SAMPLE: One hundred and seventy-one pregnant women referred to the obstetric day-care unit for assessment of newly arisen hypertension. METHODS: Early morning urine specimens were tested with four dipstick techniques (Multistix 8SG visual and automated and microalbumin/creatinine ratio visual and automated; Bayer, Elkhart, USA) as well as a fully quantitative measure of the microalbumin creatinine ratio with the DCA 2000 (a point of care assay for albumin; Bayer). These results were compared to a 24-hour urine protein measurement and measures of diagnostic accuracy/prediction are reported. MAIN OUTCOME MEASURES: Significant proteinuria (> or =0.3 g/24 hours) measured by laboratory assay. RESULTS: Automated dipstick urinalysis using the Clinitek 50 has significantly better predictive values for significant proteinuria (LR(+) 4.27, 95% CI 2.78 to 6.56; LR(-) 0.225, 95% CI 0.14 to 0.37) than conventional visual dipstick urinalysis (LR(+) 2.27, 95% CI 1.47 to 3.51; LR(-) 0.635, 95% CI 0.49 to 0.82). Dipstick microalbumin/creatinine ratio testing did not improve overall detection rates with automated or visual testing. Fully quantitative point of care measurement of albumin/creatinine ratio (ACR) was significantly better than any dipstick technique (LR(+) 14.6, 95% CI 6.74 to 31.8; LR(-) 0.069, 95% CI 0.030 to 0.16). CONCLUSIONS: This study confirms that in pregnancy automated dipstick urinalysis is a more accurate screening test for the detection of proteinuria than visual testing. ACR testing can offer a significant improvement over conventional urinalysis if a fully quantitative method of detection is employed that uses pregnancy-specific thresholds. Dipstick assessment of ACR does not improve the detection rate of significant proteinuria.

Adult↗
PubMed1988

Diagnostic value of stress radionuclide angiography in coronary artery disease: a comparison of different interpretation criteria.

In order to compare different criteria in the interpretation of stress radionuclide angiography (SRNA) 96 patients with suspected coronary artery disease (CAD) were investigated by both SRNA and coronary arteriography. The result of coronary arteriography was taken as the gold standard for the diagnosis of CAD. Left ventricular ejection fraction (LVEF) was measured at each step of the stress study using the equilibrium radionuclide technique. The diagnostic value of eight interpretation criteria based on the evolution of global LVEF during stress were compared with each other, using the ROC technique. The best diagnostic criterion proved to be the normalized increase of LVEF proposed by Goris. The most commonly used criteria, LVEF increase and LVEF measured at maximal exercise, were not optimal. In the whole population of patients, the best criterion had a sensitivity of 85% for a specificity of 80% and a specificity of 83% for a sensitivity of 80%. In the population, following exclusion of patients with preceding myocardial infarction, the specificity was 74% for a sensitivity of 80% and a sensitivity of 74% for a specificity of 80%. Thus, the choice of interpretation criteria is very important in order to optimize the sensitivity and specificity of this diagnostic test.

Angina Pectoris↗
PubMed2004

Revascularization procedures in internal carotid artery pseudo-occlusion.

BACKGROUND: Surgical treatment of patients with suspected internal carotid artery (ICA) pseudo-occlusion and reduced cerebrovascular reactivity (CVR) is still uncertain regarding the diagnostic procedures, the risks and the optimal timing as well as performance of revascularization. METHOD: From 1983-2001, 781 patients with symptomatic ICA stenosis were treated surgically. In 53 patients, a final diagnosis of extracranial ICA pseudo-occlusion was established by repeating Digital Subtraction Angiography (DSA). Angiographical findings were anterograde "string-like" filling of ICA beyond the carotid bifurcation or retrograde filling of the proximal, so called "occluded" extracranial ICA, extending up to the skull base. The CVR was reduced. All patients underwent direct surgery of extracranial carotid artery. Diagnostic parameters, peri-operative risks and postoperative course of these patients were evaluated. FINDINGS: In 40 patients (75.5%) a successful revascularization of ICA was possible. ICA pseudo-occlusion was in all cases of atheromatous origin, moreover in 8 patients combined with a floating thrombus, distal to the stenosis. Thrombectomy was done by means of Fogarty catheter. In 13 patients (24.5%), a surgical re-opening of the ICA lumen was not possible. Five of these patients showed in DSA an anterograde "string sign", eight presented retrograde filling of ICA reaching the skull base. Peri-operative mortality was 1.9%, peri-operative morbidity was 7.5%. After a 4 years (mean) follow-up, 95% of the reopened ICA remained patent. CONCLUSION: In patients with explicit carotid artery occlusion signs, careful selective DSA should be compulsory with a late series to detect ICA pseudo-occlusion. There is a chance for extracranial reopening ICA, even with compromised CVR, if anterograde "string like" or retrograde filling of proximal so called "occluded" ICA as far as the skull base is angiographically identified.

Adult↗