Optimal diagnosis of renal masses in children by combining and correlating diagnostic features of sonography and radiography.
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Child, Preschool↗
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Management of the patient with suspected temporal arteritis a decision-analytic approach.
OBJECTIVE: To perform a decision analysis of temporal arteritis (TA) to guide clinicians in the interpretation of diagnostic testing and choice of therapy. DESIGN: Computer-based decision analytic model. METHODS: A 785-node decision tree was created that reflects common testing and therapeutic options for a patient with suspected TA. A comprehensive literature search was then performed. From this search, point estimates and distributions for pooled probabilities and utilities were derived using inverse variance weighting and random effects techniques. Employing utility analysis, this decision model selects the diagnostic/therapeutic pathway resulting in the greatest utility for any user-defined set of patient characteristics on presentation. MAIN OUTCOME MEASURE: Using utility analysis, the diagnostic/therapeutic pathway that results in the least expected disutility is selected as the optimal course of action. RESULTS: The choice of diagnostic testing depends on several factors, including patient age, symptoms, and clinical findings. These factors can be used to calculate the pretest probability of TA being present. The optimal selection of diagnostic tests (laboratory or biopsy) depends on the pretest probability of disease. A temporal artery biopsy is recommended under most circumstances, with the choice of a unilateral versus bilateral biopsy depending upon blood test results and calculated pretest probability. A few scenarios exist in which blood tests alone can rule in or rule out TA without the need for biopsy. Empiric steroid therapy is almost never recommended. CONCLUSIONS: In TA, both the disease and its treatment are hazardous for the patient. Clinicians should have a very low threshold to initiate a diagnostic workup for TA. Physicians are often uncertain when a temporal artery biopsy is indicated and whether to perform a unilateral or bilateral biopsy. Often, the pathway chosen is not evidence based. Although the biopsy has long been considered the gold standard for diagnosis, it is invasive and less than 100% sensitive. The decision whether to undertake unilateral or bilateral biopsies is difficult, and our decision model delineates a method for choosing.
Age Distribution↗
Endoscopic ultrasonography.
Over the past two decades, endoscopic ultrasonography (EUS) has undergone a transition from being a novel imaging technique to a clinical diagnostic test that is necessary for the optimal management of gastrointestinal diseases. EUS has established itself as an important diagnostic modality, mainly for the detection and staging of gastrointestinal cancers. As EUS has become more widespread, research has gradually shifted towards studies that explore the effect of EUS on patient management and outcome. These outcome studies have examined the primary clinical applications of EUS, such as esophageal, gastric, pancreatic, and colorectal cancer staging, as well as the role of EUS in the diagnosis of inflammatory pancreatic diseases. Widespread use of EUS has recently led to studies that examine complications associated with the performance of the procedure. Endosonographers have continued efforts to define a clinical role for EUS in other gastrointestinal diseases, such as portal hypertension. EUS-guided fine-needle aspiration (FNA) is continuing to develop into a powerful diagnostic tool for the management of lung cancer and other mediastinal diseases. New applications for EUS-FNA are also emerging. Finally, investigators are continuing to explore the remaining frontier of EUS-guided therapy.
Biopsy, Needle↗
[Magnetic resonance angiography of the neck vessels: technique and anatomy].
The authors identified the standard projections for studying neck vessels with magnetic resonance angiography. Sixty volunteers underwent angio-MR of the arterial neck vessels with FISP 3D FT sequences obtained on the coronal and sagittal planes. The gradient-echo sequence (FISP 3D FT) was acquired with TR = 0.04-0.08 s and TE = 15 ms, with 25 degrees flip angle. Single excitated slices of thickness ranging from 1-2 mm were included in the acquisition volume. These sequences were subsequently processed by the maximum intensity projection method. Two radiologists examined our results to choose the optimal projections. We used a semiquantitative scale which allowed us to distinguish 3 different diagnostic levels for each projection: well-visualized vessels, poorly-visualized, and non-visualized ones. For each section axial rotations were performed ranging from 0 degree to 180 degrees, with 15 degrees intervals. On the coronal plane, rotations from -45 degrees to 45 degrees were the optimal ones to visualize the studied vessels. The 0 degree-15 degrees-30 degrees-45 degrees-135 degrees-165 degrees-180 degrees projections allowed the common carotids to be clearly demonstrated together with the vertebral arteries. The other projections appeared to be useless for diagnostic purposes. On the sagittal plane, rotations from 60 degrees to 120 degrees were the optimal ones. The 90 degrees projection allowed the demonstration of all the big arterial vessels of the neck, including carotid bifurcation and internal and external carotids. The assessment of the optimal diagnostic projections for angio-MR of the neck vessels is helpful to reduce post-processing time. As a matter of fact, the immediate visualization, during the examination, of the standard projections allows further acquisitions to be obtained--if needed--to try to solve specific diagnostic doubts.
Adult↗
Clinical assessment of the effect of digital filtering on the detection of ventricular late potentials.
Ventricular late potentials are low-amplitude signals originating from damaged myocardium and detected on the body surface by ECG filtering and averaging. Digital filters present in commercial equipment may interfere with the ability of arrhythmia stratification. We compared 40-Hz BiSpec (BI) and classical 40- to 250-Hz band-pass Butterworth bidirectional (BD) filters in terms of impact on time domain variables and diagnostic properties. In a transverse retrospective age-adjusted case-control study, 221 subjects with sinus rhythm without bundle branch block were divided into three groups after signal-averaged ECG acquisition: GI (N = 40), clinically normal controls, GII (N = 158), subjects with coronary heart disease without sustained monomorphic ventricular tachycardia (SMVT), and GIII (N = 23), subjects with heart disease and documented SMVT. Conventional variables analyzed from vector magnitude data after averaging to 0.3 micro V final noise were obtained by application of each filter to the averaged signal, and evaluated in pairs by numerical comparison and by diagnostic agreement assessment, using conventional and optimized thresholds of normality. Significant differences were found between BI and BD variables in all groups, with diagnostic results showing significant disagreement between both filters [kappa value of 0.61 (P<0.05) for GII and 0.31 for GIII (P = NS)]. Sensitivity for SMVT was lower with BI than with BD (65.2 vs 91.3%, respectively, P<0.05). Filters provided significantly different numerical and diagnostic results and the BI filter showed only limited clinical application to risk stratification of ventricular arrhythmia.
Age Distribution↗
Accuracy in radiographic diagnosis: Dutch practitioners and dental caries.
The effective diagnostic accuracy of dentists is the missing link in models for calculating the optimal frequency for radiographic recall. The purpose of this study was to describe the accuracy of Dutch general dental practitioners using bitewing radiographs for the diagnosis and treatment of approximal caries in dentine. Practitioners from a 10 per cent (n = 444) national random sample were sent a set of simulated bitewings, a patient description and a diagnostic response form. The radiographs showed tooth surfaces with (n = 45) and without (n = 60) dentine caries. Microradiography of the sectioned teeth was used as a diagnostic reference standard. The participants were asked to diagnose dentine caries using a five-point certainty scale and decide if restorative treatment was indicated. The response was 62 per cent (n = 276). The area under a mean receiver operating characteristic curve for the practitioners was 88 per cent of the area representing optimal accuracy. Diagnostic accuracy, however, varied considerably between dentists. For caries considered to be 'probably' in the dentine mean sensitivity was 54 per cent (s.d. 14 per cent) and specificity was 97 per cent (s.d. 5 per cent). The pooled restorative treatment decisions of the dentists had a mean sensitivity of 62 per cent and a specificity of 96 per cent. More surfaces were considered in need of treatment than were diagnosed as 'probably' having dentine caries. Treatment decisions were more accurate than diagnostic ability might indicate. Paradoxically this may be because errors in visual ability were partly compensated for by 'over treatment' decisions.
Decision Making↗
Current status of dual-sensor pacemaker systems for correction of chronotropic incompetence.
Rate-adaptive pacing has been shown to improve exercise capacity in patients with chronotropic incompetence. However, all sensors used to adapt the pacing rate to meet metabolic demands show typical limitations. To overcome these, concepts using 2 sensors for rate adaptation have been developed, combining an unspecific but fast-reacting sensor with a specific but slower-reacting one. Clinical performance of these dual-sensor pacemaker systems is related to 3 factors: (1) choice of sensors, (2) mode of sensor integration, and (3) algorithms for automatic optimization of the integrated sensor response. Clinical studies using dual-sensor rate-adaptive pacing systems have demonstrated their ability to mimic normal sinus rate during different forms of exercise, avoiding inadequate or delayed rate response. However, to avoid combining the disadvantages of both single sensors, dual-sensor rate-adaptive systems need effective automatic algorithms. Sensor cross-check should be quick and combine fast reactivity and high specificity, particularly so as to prevent overpacing. Programmable rate response-related parameters should continuously be optimized. The pacemaker should provide diagnostic facilities during exercise to simulate short-term sensor performance at different settings and memory functions to evaluate long-term sensor performance. Assessment and eventually deactivation of all automatic functions should be possible. Finally, even with automatic algorithms for sensor optimization, maximal benefit from a dual-sensor system can only be achieved if the physician is able to identify and correct pitfalls of each system.
Algorithms↗
Improvement of diagnostic accuracy and screening conditions with liquid-based cytology.
The aim of this population-based study was to compare the histological follow-up diagnoses of cervicocytological neoplasia (dysplasia, carcinoma in situ and carcinoma) in conventional Papanicolaou (CP) smear and ThinPrep PapTest samples (TP). All cytological samples from the County of Funen, Denmark, in the periods 2000 (n = 34,832) and 2002 (n = 29,995) were included in the study. In 2000 and 2002, the specimens were CP and TP, respectively. The detection rate of > or = mild dysplasia was 0.8% in CP and 1.4% in TP, showing a 75% increase in TP when compared with CP (p < 0.001). Histological follow-up of > or = moderate dysplasia revealed a neoplastic lesion in 77.1% and 87.9% in CP and TP, respectively (P < 0.001). The present study indicates that the diagnostic accuracy of cervical cytology is improved with liquid-based cytology. In addition, we focus on the optimized cellular material that shows the diagnostic details very clearly to the microscopist and leads to radically improved screening conditions.
Adult↗
Urinary infections in the elderly: symptomatic of asymptomatic?
Asymptomatic bacteriuria is common in the elderly, occurring in as many as 25-50% of elderly nursing home residents. Asymptomatic bacteriuria itself should not be treated with antimicrobial therapy. Difficulties in communication, chronic genitourinary symptoms, and the high frequency of positive urine cultures, make ascertainment of symptomatic infection problematic for the functionally impaired elderly. Chronic genitourinary symptoms are not a manifestation of acute urinary infection, although acute deterioration in symptoms may be consistent with infection. Fever in an institutionalized elderly subject with a positive urine culture and without an indwelling catheter is due to urinary infection in less than 10% of episodes. However, there are no criteria to differentiate urinary infection from other sites in this clinical scenario. Thus, neither urine culture nor clinical presentation allows a diagnosis of symptomatic urinary infection to be made with a high level of certainty. Decisions with respect to antimicrobial therapy must be made on an individual basis and with an understanding of these diagnostic limitations. It is not realistic to expect to optimize antimicrobial usage in this population until issues of diagnostic uncertainty are addressed.
Aged↗
Capsule endoscopy: practical applications.
Few advances in the history of gastroenterology have made as dramatic an impact on the diagnosis of gastrointestinal disease as the development and rapid clinical implementation of wireless capsule endoscopy. Less than 4 years after the landmark publication, capsule endoscopy is widely considered an essential component of the diagnostic workup of obscure gastrointestinal bleeding, and its role is expanding in the diagnosis of small bowel diseases such as Crohn's disease. This review appraises the available literature and highlights practical aspects of capsule endoscopy of interest to the clinician. We discuss safety concerns, optimal preparation for the procedure, diagnostic utility as compared to conventional methods, indications for capsule endoscopy, and outcomes.
Abdominal Pain↗
Reproducibility and clinical value of 18F-fluorodeoxyglucose positron emission tomography in recurrent melanoma.
The purpose of this study was to assess the reproducibility and clinical impact of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with (suspected) recurrent melanoma. The clinical value of PET was prospectively measured in 58 consecutive patients referred for PET because of unresolved clinical questions after conventional work-up. Diagnostic understanding and therapy choice by referring physicians were evaluated before, directly after, and 6 months after PET. Observer agreement of PET readings was measured with respect to various parameters (interpretation, number and localization of lesions, 'clinically decisive' metastases), using intra-class correlation coefficients. FDG PET improved diagnostic understanding in 33 cases (57%). In six patients (10%), diagnostic understanding was solely based on PET information. According to the attending clinicians, PET contributed to a positive change of planned treatment in 23 patients (40%) and increased confidence in the chosen treatment in 23 (40%). Observer agreement of PET readings was very high (intra-class correlation coefficients were between 0.87 and 0.94). The diagnostic value related especially to the whole-body scan technique and the superior specificity, compared to conventional work-up. It is concluded that, in problematical cases with (suspected) recurrent melanoma, 18F-FDG PET had considerable impact on diagnostic understanding and management. Together with the excellent observer reliability, these results justify further studies to determine the optimal place of PET in routine diagnostic algorithms in recurrent melanoma.
Adult↗
Diagnostic evaluation of the adrenal incidentaloma: decision and cost-effectiveness analyses.
UNLABELLED: The goal of this study was to examine the clinical and economic outcomes of alternative diagnostic strategies for differentiating benign from malignant adrenal masses. METHODS: We used cost-effectiveness assessment derived from decision analysis and the economic perspective of the payer of health care services. One-time evaluation with fine-needle aspiration (FNA) and combinations of chemical-shift MRI, noncontrast CT, 131I-6beta-iodomethylnorcholesterol (NP-59) scintigraphy, with or without FNA, in a hypothetical cohort of 1000 patients with incidentally discovered unilateral, nonhypersecretory adrenal masses. We calculated and compared the diagnostic effectiveness, costs and cost-effectiveness of the alternative strategies based on estimates from published literature and institutional charge data. RESULTS: At an assumed baseline malignancy rate of 0.25, diagnostic utility varied from 0.31 (CT0) to 0.965 (NP-59) and diagnostic accuracy from 0.655 [noncontrast CT using a cut-off attenuation value of > or = 0 (CT0)] to 0.983 (NP-59). The average cost per patient per strategy ranged from $746 (NP-59) to $1745 (MRI +/- FNA). The best and worst potential cost-to-diagnostic utility ratios were 773 (NP-59) and 2839 (CT0) and 759 (NP-59) and 1982 (MRI +/- FNA) for cost and diagnostic accuracy, respectively. The NP-59 strategy was the optimal choice regardless of the expected outcome examined: cost, diagnostic utility, diagnostic accuracy or cost-effectiveness. Varying the prevalence of malignancy did not alter the cost-effectiveness advantage of NP-59 over the other diagnostic modalities. CONCLUSION: Based on available estimates of reimbursement costs and diagnostic test performance and using reasonable clinical assumptions, our results indicate that the NP-59 strategy is the most cost-effective diagnostic tool for evaluating adrenal incidentalomas over a wide range of malignancy rates and that additional clinical studies are warranted to confirm this cost-effectiveness advantage.
Adosterol↗
Optimized approach to decision fusion of heterogeneous data for breast cancer diagnosis.
As more diagnostic testing options become available to physicians, it becomes more difficult to combine various types of medical information together in order to optimize the overall diagnosis. To improve diagnostic performance, here we introduce an approach to optimize a decision-fusion technique to combine heterogeneous information, such as from different modalities, feature categories, or institutions. For classifier comparison we used two performance metrics: The receiving operator characteristic (ROC) area under the curve [area under the ROC curve (AUC)] and the normalized partial area under the curve (pAUC). This study used four classifiers: Linear discriminant analysis (LDA), artificial neural network (ANN), and two variants of our decision-fusion technique, AUC-optimized (DF-A) and pAUC-optimized (DF-P) decision fusion. We applied each of these classifiers with 100-fold cross-validation to two heterogeneous breast cancer data sets: One of mass lesion features and a much more challenging one of microcalcification lesion features. For the calcification data set, DF-A outperformed the other classifiers in terms of AUC (p < 0.02) and achieved AUC=0.85 +/- 0.01. The DF-P surpassed the other classifiers in terms of pAUC (p < 0.01) and reached pAUC=0.38 +/- 0.02. For the mass data set, DF-A outperformed both the ANN and the LDA (p < 0.04) and achieved AUC=0.94 +/- 0.01. Although for this data set there were no statistically significant differences among the classifiers' pAUC values (pAUC=0.57 +/- 0.07 to 0.67 +/- 0.05, p > 0.10), the DF-P did significantly improve specificity versus the LDA at both 98% and 100% sensitivity (p < 0.04). In conclusion, decision fusion directly optimized clinically significant performance measures, such as AUC and pAUC, and sometimes outperformed two well-known machine-learning techniques when applied to two different breast cancer data sets.
Algorithms↗
In vitro diagnostic evaluation of patients with inhalant allergies: summary of probability outcomes comparing results of CLA- and CAP-specific immunoglobulin E test systems.
For the diagnosis of allergy, presence of allergen-specific immunoglobulin E (IgE) usually is established either by allergen skin tests or by in vitro allergen-specific IgE measurements. However, in vitro assays of specific IgE often are modified as manufacturers improve allergens or change reagents to optimize test performance, affecting the diagnostic performance of in vitro allergen-specific IgE assays. This investigation compares the diagnostic outcomes of the Hitachi Chemical Diagnostics chemiluminescent assay (CLA) and Pharmacia, capsulated hydrophilic carrier polymer (CAP) in vitro allergen-specific IgE test methods in patients with inhalant allergy to a panel of selected allergens. Sera were obtained from 60 consecutive patients who had a clinical history suggesting inhalant allergy and were evaluated by allergen skin-prick test (SPT). Only patients with clinical findings of allergic asthma or rhinoconjunctivitis were included. Sera from patients with at least one positive SPT, which clinically correlated with the case history, were used for specific IgE measurements. Sensitivity and specificity were defined as conditional probabilities describing performances of the CAP system and the CLA system in reference to a standard composed of a combination of allergen-specific symptoms and a positive SPT. A test concordance of 79% was found between the CLA and CAP test results with a correlation coefficient of 0.8. Allergen-specific IgE assay sensitivity of the CLA and CAP systems was similar and allergen dependent, ranging from 67 to 100%. Assay specificity ranged from 39 to 86% for the CLA system and from 36 to 81% for the CAP system. When comparing the specific IgE results with allergen SPTs, 75% (+/- 3%) of CLApositive patients had a positive SPT, and 92% (+/- 4%) of CAPpositive patients had a positive SPT. Eighty-four percent (+/- 4%) of CLAnegative patients had a negative SPT, whereas 69% (+/- 5%) of CAPnegative patients had a negative SPT. The overall concordance between skin tests and in vitro tests was 76% for CLA and 67% for CAP. CLA and CAP score values showed good correlation and both tests may be useful when skin tests cannot be performed to identify subjects with IgE-mediated allergy. The CLA and CAP assays for allergen-specific IgE may be useful as part of an initial allergy evaluation because of the high negative predictive value of negative test results. For the majority of allergens the sensitivity was high. However, the specificity of both in vitro tests was low, indicating that positive in vitro test results should be evaluated carefully in conjunction with clinical symptoms and allergen-specific skin tests to determine the clinical relevance of the allergen sensitization.
Adult↗
Coexistence of atherosclerotic renal artery stenosis with primary hyperaldosteronism.
The discovery of two forms of secondary hypertension in the same patient is unusual and suggests similar pathophysiological mechanisms, a predisposition to one type in the presence of the other or a chance occurrence. We describe two patients with renal artery stenosis who after successful correction of the stenotic lesions were discovered to have primary hyperaldosteronism associated with bilateral adrenal hyperplasia. Initially prior to revascularisation of the renal artery stenosis, the diagnosis of primary hyperaldosteronism was not evident. Both patients were subjected to further diagnostic evaluation after the appearance of hypokalaemia in one patient and continued resistant hypertension in both patients. The addition of spironolactone therapy reduced blood pressure impressively in both patients. Clinicians should be aware of the possibility that these two forms of secondary hypertension may be present in the same patient and that optimal blood pressure control requires diagnostic assessment and intervention for both disorders.
Aged↗
[Anesthesia and sleep apnea syndrome].
The perioperative risk for patients with obstructive sleep apnea syndrome and the optimal anaesthesiological management of these patients have not been well elucidated. The prevalence of obstructive sleep apnea with significant symptoms is estimated to be 4% in men and 2% in women. However, in 80-95% of patients this syndrome is not sufficiently diagnosed. Thus identification of patients at risk and a thorough multidisciplinary diagnostic approach are essential for optimal perioperative management. The risk of perioperative complications, like cardiopulmonary compromise, and difficulties in airway management is elevated. The most important aspects of perioperative management include evaluation of intubating conditions, careful search for cardiopulmonary morbidity, permanent control of patient airways, sensible use of anaesthetics, sedatives, and narcotics, and strict monitoring of vital signs. If ambulatory nasal continuous positive airway pressure (CPAP) therapy has been established preoperatively, this should be continued in the perioperative period. Postoperative monitoring should be performed in an intensive care or intermediate care unit. Controlled clinical studies on the best perioperative management of patients with obstructive sleep apnea are urgently required.
Ambulatory Surgical Procedures↗
Diagnosis and treatment of traumatic intracranial hematomas and hydromas according to the hospital type.
The capability to diagnose and treat is essentially a combination of the professional qualification of the medical specialists and the degree of availability of all necessary instrumentation specific for the respective disorders in the medical institution. 610 patient treated in the Neurosurgery Department of the Plovdiv University of Medicine between 1975 and 1990 were entered into this study. Three periods of the Department's diagnostic capabilities are differentiated within this interval. They are used as an analogue model for the assessment of diagnostic and therapeutic capabilities of the different types of hospitals. The patients are categorized as survivors and dead, diagnosed and nondiagnosed in the three periods. It is concluded that all methods available should be used in diagnosing traumatic intracranial hematomas. Their condition permitting patients should always be transported to a neurosurgery clinic where an optimal environment is provided for diagnostics and treatment. Employment of a portable echoencephalograph can additionally augment the diagnostic capabilities of the consultant neurosurgeon in small health-care units especially in cases in which transportation of the patient to a neurosurgery clinic is contraindicated.
Brain Injuries↗
Dose-area product measurements in a range of common orthopaedic procedures and their possible use in establishing local diagnostic reference levels.
There is a national drive towards establishing reference doses for radiological procedures with the aim of optimizing patient doses. Furthermore, the establishment of diagnostic reference level doses became a legal requirement for all hospitals on 13 May 2000. However, to date there are little published data on patient radiation doses from fluoroscopic procedures during orthopaedic surgery. Data relating to patient dose for 492 patients undergoing fluoroscopic examinations during a range of surgical orthopaedic procedures in 1997-1998 have been analysed. Median dose-area product (DAP) readings and interquartile ranges for a variety of common fluoroscopic orthopaedic procedures are presented. In general, the median DAP for procedures on limbs and extremities was quite low (0.04-1.62 Gy cm2), with screening times in the range 0.2-2.0 min, whilst for procedures involving the hips and spine the median DAP was considerably higher (0.4-10.2 Gy cm2), although overall screening times were similar, in the range 0.2-1.4 min. Approximate effective doses have been estimated. For procedures involving the limbs and extremities, the effective dose was generally less than 10 microSv, and for procedures involving the hips and spine it was found that the effective dose could rise to about 1 mSv. Collective doses for each procedure have been calculated to inform prioritization of procedures for local dose reduction strategies.
Arthrography↗