Should 3K zoom function be used for detection of pneumothorax in cesium iodide/amorphous silicon flat-panel detector radiographs presented on 1K-matrix soft copies?

The purpose of the study was to evaluate observer performance in the detection of pneumothorax with cesium iodide and amorphous silicon flat-panel detector radiography (CsI/a-Si FDR) presented as 1K and 3K soft-copy images. Forty patients with and 40 patients without pneumothorax diagnosed on previous and subsequent digital storage phosphor radiography (SPR, gold standard) had follow-up chest radiographs with CsI/a-Si FDR. Four observers confirmed or excluded the diagnosis of pneumothorax according to a five-point scale first on the 1K soft-copy image and then with help of 3K zoom function (1K monitor). Receiver operating characteristic (ROC) analysis was performed for each modality (1K and 3K). The area under the curve (AUC) values for each observer were 0.7815, 0.7779, 0.7946 and 0.7066 with 1K-matrix soft copies and 0.8123, 0.7997, 0.8078 and 0.7522 with 3K zoom. Overall detection of pneumothorax was better with 3K zoom. Differences between the two display methods were not statistically significant in 3 of 4 observers (p-values between 0.13 and 0.44; observer 4: p = 0.02). The detection of pneumothorax with 3K zoom is better than with 1K soft copy but not at a statistically significant level. Differences between both display methods may be subtle. Still, our results indicate that 3K zoom should be employed in clinical practice.

Diagnostic criteria for hematopoietic stem cell transplant-associated microangiopathy: results of a consensus process by an International Working Group

BACKGROUND AND OBJECTIVES: There are no widely accepted criteria for the definition of hematopoietic stem cell transplant -associated microangiopathy (TAM). An International Working Group was formed to develop a consensus formulation of criteria for diagnosing clinically significant TAM. DESIGN AND METHODS: The participants proposed a list of candidate criteria, selected those considered necessary, and ranked those considered optional to identify a core set of criteria. Three obligatory criteria and four optional criteria that ranked highest formed a core set. In an appropriateness panel process, the participants scored the diagnosis of 16 patient profiles as appropriate or not appropriate for TAM. Using the experts' ratings on the patient profiles as a gold standard, the sensitivity and specificity of 24 candidate definitions of the disorder developed from the core set of criteria were evaluated. A nominal group technique was used to facilitate consensus formation. The definition of TAM with the highest score formed the final PROPOSAL. RESULTS: The Working Group proposes that the diagnosis of TAM requires fulfilment of all of the following criteria: (i) >4% schistocytes in blood; (ii) de novo, prolonged or progressive thrombocytopenia (platelet count <50 x 109/L or 50% or greater reduction from previous counts); (iii) sudden and persistent increase in lactate dehydrogenase concentration; (iv) decrease in hemoglobin concentration or increased transfusion requirement; and (v) decrease in serum haptoglobin. The sensitivity and specificity of this definition exceed 80%. INTERPRETATION AND CONCLUSIONS: The Working Group recommends that the presented criteria of TAM be adopted in clinical use, especially in scientific trials.

MR cholangiopancreatography: 1.5T versus 3T

Soon after its introduction in 1991, MR cholangiopancreatography has become an established diagnostic tool for the evaluation of the pancreaticobiliary ductal system at a field strength of 1.5T. It remains unclear whether MR cholangiopancreatography performed at 3T will benefit from the higher magnetic field strength or whether a field strength of 1.5T should continue to be considered the gold standard for MR cholangiopancreatography. This article reviews the current literature on the benefits and drawbacks of MR cholangiopancreatography at 3T compared with a standard field strength of 1.5T. Field strength-related artifacts that affect MR cholangiopancreatography at 3T also are discussed.

Nanoduct(R) sweat testing for rapid diagnosis in newborns, infants and children with cystic fibrosis

Determination of chloride concentration in sweat is the current diagnostic gold standard for Cystic Fibrosis (CF). Nanoduct(R) is a new analyzing system measuring conductivity which requires only 3 microliters of sweat and gives results within 30 minutes. The aim of the study was to evaluate the applicability of this system in a clinical setting of three children's hospitals and borderline results were compared with sweat chloride concentration. Over 3 years, 1,041 subjects were tested and in 946 diagnostic results were obtained. In 95 children, Nanoduct(R) failed (9.1% failure rate), mainly due to failures in preterm babies and newborns. Assuming 59 mmol/L as an upper limit of normal conductivity, all our 46 CF patients were correctly diagnosed (sensitivity 100%, 95% CI: 93.1-100; negative predicted value 100% (95% CI: 99.6-100) and only 39 non CF's were false positive (39/900, 4.3%; specificity 95.7%, 95%CI: 94.2-96.9, positive predicted value 54.1% with a 95%CI: 43.4-65.0). Increasing the diagnostic limit to 80 mmol/L, the rate fell to 0.3% (3/900). CF patients had a median conductivity of 115 mmol/L; the non-CF a median of 37 mmol/L. In conclusion, the Nanoduct(R) test is a reliable diagnostic tool for CF diagnosis: It has a failure rate comparable to other sweat tests and can be used as a simple bedside test for fast and reliable exclusion, diagnosis or suspicion of CF. In cases with borderline conductivity (60-80 mmol/L) other additional methods (determination of chloride and genotyping) are indicated.

Actigraphy in agitated patients with dementia : Monitoring treatment outcomes

Especially in pharmacotherapeutic research, a variety of methods to monitor behavioural and psychological symptoms of dementia (BPSD) are currently being discussed. To date, the most frequently used of these are clinical scales, which, however, are subjective and highly dependent on personnel resources. In our study, we tested the usefulness of actigraphy as a more direct and objective way to measure day-night rhythm disturbances and agitated behaviour.After a baseline assessment, 24 patients with probable dementia of the Alzheimer type (NINCDS-ADRDA) and agitated behaviour received either 3 mg melatonin (n=7), 2.5 mg dronabinol (n=7), or placebo (n=10) for two weeks. In addition, 10 young and 10 elderly healthy subjects were examined as a control group. Motor activity levels were assessed using an actigraph worn continuously on the wrist of the non-dominant hand. At the beginning and the end of the study, patients' Neuropsychiatric Inventory (NPI) scores were also assessed.In the verum group, actigraphic nocturnal activity (P=0.001), NPI total score (P=0.043), and NPI agitation subscale score (P=0.032) showed significant reductions compared to baseline. The treatment-baseline ratio of nocturnal activity (P=0.021) and treatment-baseline difference of the nocturnal portion of 24 h activity (P=0.012) were reduced. Patients' baseline activity levels were similar to those seen in healthy elderly subjects. Younger healthy subjects exhibited higher motor activity even at night. There was no correlation between actigraphy and NPI.Both actigraphic measures and the gold standard clinical scale were able to distinguish between the verum and placebo groups. However, because they did not correlate with each other, they clearly represent different aspects of BPSD, each of which reacts differently to therapy. As a result, actigraphy may well come to play an important role in monitoring treatment success in BPSD.

Stereology meets electron tomography: towards quantitative 3D electron microscopy

Stereological tools are the gold standard for accurate (i.e., unbiased) and precise quantification of any microscopic sample. The past decades have provided a broad spectrum of tools to estimate a variety of parameters such as volumes, surfaces, lengths, and numbers. Some of them require pairs of parallel sections that can be produced by either physical or optical sectioning, with optical sectioning being much more efficient when applicable. Unfortunately, transmission electron microscopy could not fully profit from these riches, mainly because of the large depth of field. Hence, optical sectioning was a long-time desire for electron microscopists. This desire was fulfilled with the development of electron tomography that yield stacks of slices from electron microscopic sections. Now, parallel optical slices of a previously unimagined small thickness (2-5 nm axial resolution) can be produced. These optical slices minimize problems related to overprojection effects, and allow for direct stereological analysis, e.g., volume estimation with the Cavalieri principle and number estimation with the optical disector method. Here, we demonstrate that the symbiosis of stereology and electron tomography is an easy and efficient way for quantitative analysis at the electron microscopic level. We call this approach quantitative 3D electron microscopy.

Microalbuminuria in diabetes mellitus: efficacy of a new screening method in comparison with timed overnight urine collection

Diabetic nephropathy and end-stage renal failure are still a major cause of mortality amongst patients with diabetes mellitus (DM). In this study, we evaluated the Clinitek-Microalbumin (CM) screening test strip for the detection of microalbuminuria (MA) in a random morning spot urine in comparison with the quantitative assessment of albuminuria in the timed overnight urine collection ("gold standard"). One hundred thirty-four children, adolescents, and young adults with insulin-dependent DM Type 1 were studied at 222 outpatient visits. Because of urinary tract infection and/or haematuria, the data of 13 visits were excluded. Finally, 165 timed overnight urine were collected in the remaining 209 visits (79% sample per visit rate). Ten (6.1%) patients presented MA of > or =15 microg/min. In comparison however, 200 spot urine could be screened (96% sample/visit rate) yielding a significant increase in compliance and screening rate (P<.001, McNemar test). Furthermore, at 156 occasions, the gold standard and CM could be directly compared. The sensitivity and the specificity for CM in the spot urine (cut-off > or =30 mg albumin/l) were 0.89 [95% confidence interval (CI) 0.56-0.99] and 0.73 (CI 0.66-0.80), respectively. The positive and negative predictive value were 0.17 (CI 0.08-0.30) and 0.99 (CI 0.95-1.00), respectively. Considering CM albumin-to-creatinine ratio, the results were poorer than with the albumin concentration alone. Using CM instead of quantitative assessment of albuminuria is not cost-effective (35 US dollars versus 60 US dollars/patient/year). In conclusion, to exclude MA, the CM used in the random spot urine is reliable and easy to handle, but positive screening results of > or =30 mg albumin/l must be confirmed by analyses in the timed overnight collected urine. Although the screening compliance is improved, in terms of analysing random morning spot urine for MA, we cannot recommend CM in a paediatric diabetic outpatient setting because the specificity is far too low.

Extended resection for thyroid disease has less operative morbidity than limited resection

BACKGROUND: Theodor Kocher, surgeon and Nobel laureate, has influenced thyroid surgery all over the world: his treatment for multinodular goiter-subtotal thyroidectomy-has been the "Gold Standard" for more than a century. However, based on a new understanding of molecular growth mechanisms in goitrogenesis, we set out to evaluate if a more extended resection yields better results. METHODS: Four thousand three hundred and ninety-four thyroid gland operations with 5,785 "nerves at risk" were prospectively analyzed between 1972 and 2002. From 1972 to 1990, the limited Kocher resections were performed, and from 1991 to 2002 a more radical resection involving at least a hemithyroidectomy was performed. RESULTS: The incidence of postoperative nerve palsy was 3.6%; in the first study period and 0.9%; in the second (P < 0.001, Fisher's exact). Postoperative hypoparathyroidism decreased from 3.2%; in the first period to 0.64%; in the second (P < 0.01). The rate of reoperation for recurrent disease was 11.1%; from 1972 to 1990 and 8.5%; from 1991 to 2002 (P < 0.01). CONCLUSIONS: Extended resection for multinodular goiter not only significantly reduced morbidity, but also decreased the incidence of operations for recurrent disease. Our findings in a large cohort corroborate the suggestions that Kocher's approach should be replaced by a more radical resection, which actually was his original intention more than 130 years ago.

Ultrasound-guided blocks for the treatment of chronic pain

Ultrasound (US) is an emerging imaging technique in interventional pain management. The main advantages are the identification of soft tissues, vessels, and nerves, without exposing patients and personnel to radiation, the possibility to perform continuous imaging, and the visualization of the fluid injected in a real-time fashion. Possible applications are nerve blocks of the cervical and lumbar zygapophysial joints, stellate ganglion block, intercostal nerve blocks, occipital nerve blocks, blocks of the inguinal nerves, peripheral nerve blocks of the extremities, blocks of painful stump neuromas, caudal epidural injections, and injections of tender points. US may also be used for destructive procedures, such as cryoanalgesia, radiofrequency lesions, or chemical neurolysis. The increasing published data available suggest that US has a potential usefulness in interventional pain management, but also limitations. There is still a need for clinical trials investigating efficacy and safety of US-guided pain procedures. Until these studies are made, fluoroscopy or computed tomography remain the gold standard for most interventional pain procedures.

[Diagnosis and therapy of depression in the heart disease patient]

Even though depressions and depressive symptoms are frequently observed in patients with medical diseases, their psychological problems are often neither diagnosed nor treated. Diagnosis of mood state might be easy in isolated cases yet it often is not since the precise nature of normal mood cannot be expressed in quantitative terms. Furthermore, depression can only be diagnosed based on the doctor's clinical appraisal and the patient's own description of his/her complaints. There is no gold standard on which depressive symptoms can be based on--and further on, depression is not a diagnosis. Instead, it is a syndrome that calls for differential diagnoses before treatment can be offered. Diagnosing depressive comorbidity in patients with medical complaints is even more difficult because of the overlap between symptoms of depression and accompanying symptoms of the somatic illness e.g. lack of energy. Although depressive states have been known to be a risk factor for the prognosis of patients with coronary heart disease for a long time, there is a paucity of research about the therapy these patients undergo due to the fact that tricyclic anti-depressants can have cardiotoxic effects on patients with heart disease. The treatment of depression in these patients has become a much lower risk since the introduction of serotonin reuptake inhibitors. There is widespread evidence that depressive comorbidity has a negative impact on the prognosis of medical disorders. Despite the complex nature of diagnosing depression, proper diagnosis and treatment is increasingly important in internal medicine and especially cardiology.

A multiplex real-time PCR assay for rapid detection and differentiation of 25 bacterial and fungal pathogens from whole blood samples

Early detection of bloodstream infections (BSI) is crucial in the clinical setting. Blood culture remains the gold standard for diagnosing BSI. Molecular diagnostic tools can contribute to a more rapid diagnosis in septic patients. Here, a multiplex real-time PCR-based assay for rapid detection of 25 clinically important pathogens directly from whole blood in <6 h is presented. Minimal analytical sensitivity was determined by hit rate analysis from 20 independent experiments. At a concentration of 3 CFU/ml a hit rate of 50% was obtained for E. aerogenes and 100% for S. marcescens, E. coli, P. mirabilis, P. aeruginosa, and A. fumigatus. The hit rate for C. glabrata was 75% at 30 CFU/ml. Comparing PCR identification results with conventional microbiology for 1,548 clinical isolates yielded an overall specificity of 98.8%. The analytical specificity in 102 healthy blood donors was 100%. Although further evaluation is warranted, our assay holds promise for more rapid pathogen identification in clinical sepsis.

VMC++ versus BEAMnrc: a comparison of simulated linear accelerator heads for photon beams

BEAMnrc, a code for simulating medical linear accelerators based on EGSnrc, has been bench-marked and used extensively in the scientific literature and is therefore often considered to be the gold standard for Monte Carlo simulations for radiotherapy applications. However, its long computation times make it too slow for the clinical routine and often even for research purposes without a large investment in computing resources. VMC++ is a much faster code thanks to the intensive use of variance reduction techniques and a much faster implementation of the condensed history technique for charged particle transport. A research version of this code is also capable of simulating the full head of linear accelerators operated in photon mode (excluding multileaf collimators, hard and dynamic wedges). In this work, a validation of the full head simulation at 6 and 18 MV is performed, simulating with VMC++ and BEAMnrc the addition of one head component at a time and comparing the resulting phase space files. For the comparison, photon and electron fluence, photon energy fluence, mean energy, and photon spectra are considered. The largest absolute differences are found in the energy fluences. For all the simulations of the different head components, a very good agreement (differences in energy fluences between VMC++ and BEAMnrc <1%) is obtained. Only a particular case at 6 MV shows a somewhat larger energy fluence difference of 1.4%. Dosimetrically, these phase space differences imply an agreement between both codes at the <1% level, making VMC++ head module suitable for full head simulations with considerable gain in efficiency and without loss of accuracy.

Forget the blood, not the stone! Microhaematuria in acute urolithiasis and the role of early CT scanning

BACKGROUND: Although urinalysis is simple and inexpensive to perform, the finding of microhaematuria on urinalysis may be unreliable for diagnosing urolithiasis. OBJECTIVE: To evaluate microhaematuria as a diagnostic marker for urolithiasis compared with low-dose unenhanced multidetector computed tomography (MDCT) as the "gold standard". SETTING: A level 1 emergency department in a tertiary referral university teaching hospital. DESIGN: Retrospective analysis. METHODS: A study was undertaken to assess whether the finding of microhaematuria was diagnostic for urolithiasis using a low-dose unenhanced MDCT-based diagnosis as the reference standard by reviewing the records of all patients who presented to the emergency department with colicky flank pain and underwent a CT scan between January 2003 and December 2005. RESULTS: Urolithiasis was present (as defined by low-dose unenhanced MDCT) in 507/638 patients (79%); 341/638 (53%) were true positive for urolithiasis, 76 (12%) were true negative, 55 (9%) were false positive and 166 (26%) were false negative. Microhaematuria as a test for urolithiasis in patients presenting to the emergency department therefore has a sensitivity, specificity, positive predictive value and negative predictive value of 67%, 58%, 86% and 31%, respectively. 58% of the urinalysis results were negative for haematuria in the subset of patients with significant alternative diagnoses. CONCLUSIONS: The sensitivity, specificity and negative predictive value of microhaematuria on urinalysis for urolithiasis using unenhanced MDCT as the reference standard were low. This suggests that, when urolithiasis is clinically suspected, unenhanced MDCT is indicated without urinalysis being a prerequisite.

Pelvic radiography in ATLS algorithms: A diminishing role?

ABSTRACT: BACKGROUND: Pelvic x-ray is a routine part of the primary survey of polytraumatized patients according to Advanced Trauma Life Support (ATLS) guidelines. However, pelvic CT is the gold standard imaging technique in the diagnosis of pelvic fractures. This study was conducted to confirm the safety of a modified ATLS algorithm omitting pelvic x-ray in hemodynamically stable polytraumatized patients with clinically stable pelvis in favour of later pelvic examination by CT scan. METHODS: We conducted a retrospective analysis of all polytraumatized patients in our emergency room between 01.07.2004 and 31.01.2006. Inclusion criteria were blunt abdominal trauma, initial hemodynamic stability and a stable pelvis on clinical examination. We excluded patients requiring immediate intervention because of hemodynamic instability. RESULTS: We reviewed the records of n = 452 polytraumatized patients, of which n = 91 fulfilled inclusion criteria (56% male, mean age = 45 years). The mechanism of trauma included 43% road traffic accidents, 47% falls. In 68/91 (75%) patients, both a pelvic x-ray and a CT examination were performed; the remainder had only pelvic CT. In 6/68 (9%) patients, pelvic fracture was diagnosed by pelvic x-ray. None of these 6 patients was found having a false positive pelvic x-ray, i.e. there was no fracture on pelvic CT scan. In 3/68 (4%) cases a fracture was missed in the pelvic x-ray, but confirmed on CT (false negative on x-ray). None of the diagnosed fractures needed an immediate therapeutic intervention. 5 (56%) were classified type A fractures, and another 4 (44%) B 2.1 in computed tomography (AO classification). One A 2.1 fracture was found in a clinically stable patient who only received CT scan (1/23). CONCLUSION: While pelvic x-ray is an integral part of ATLS assessment, this retrospective study suggests that in hemodynamically stable patients with clinically stable pevis, its sensitivity is only 67% and it may safely be omitted in favor of a pelvic CT examination if such is planned in adjunct assessment and available. The results support the safety and utility of our modified ATLS algorithm. A randomized controlled trial using the algorithm can safely be conducted to confirm the results.

Radiographic analysis of femoroacetabular impingement with Hip2Norm-reliable and validated

The purpose of this study was to validate the accuracy, consistency, and reproducibility/reliability of a new method for correction of pelvic tilt and rotation of radiographic hip parameters for pincer type of femoroacetabular impingement on an anteroposterior pelvic radiograph. Thirty cadaver hips and 100 randomized, blinded AP pelvic radiographs were used for investigation. To detect the software accuracy, the calculated femoral head coverage and classic hip parameters determined with our software were compared to reference measurements based on CT scans or conventional radiographs in a neutral orientation as gold standard. To investigate software consistency, differences among the different parameters for each cadaver pelvis were calculated when reckoned back from a random to the neutral orientation. Intra- and interobserver comparisons were used to analyze the reliability and reproducibility of all parameters. All but two parameters showed a good-to-very good accuracy with the reference measurements. No relevant systematic errors were detected in the Bland-Altman analysis. Software consistency was good-to-very good for all parameters. A good-to-very good reliability and reproducibility was found for a substantial number of the evaluated radiographic acetabular parameters. The software appears to be an accurate, consistent, reliable, and reproducible method for analysis of acetabular pathomorphologies.