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At least 1,531 records · Page 85Linked to original sources
PubMed1990

Accuracy of diagnosis of choroidal melanomas in the Collaborative Ocular Melanoma Study. COMS report no. 1.

In the 3-year period during which patients were enrolled into the Collaborative Ocular Melanoma Study, 413 eyes with clinical diagnoses of choroidal melanoma were examined histopathologically as of December 31, 1989. Four hundred eleven of these eyes were found to be diagnosed correctly. One eye, removed after preoperative external beam radiation, was found to have a hemangioma. The second eye, removed after radioactive iodine plaque placement, was described as a magnocellular nevus (melanocytoma) by four of the five pathologists on the Collaborative Ocular Melanoma Study Pathology Review Committee. The Collaborative Ocular Melanoma Study misdiagnosis rate of 0.48% is the lowest ever reported. The major challenge with regard to posterior uveal melanomas is no longer that of correct diagnosis but rather determination of the optimal treatment.

Adult↗
PubMed2004

Aspergillus galactomannan enzyme immunoassay and quantitative PCR for diagnosis of invasive aspergillosis with bronchoalveolar lavage fluid.

Invasive pulmonary aspergillosis (IPA) is frequent and often fatal in hematopoietic stem cell transplant patients. Diagnosis requires microbiological or histopathologic demonstration of the organism in tissues; however, cultivation of Aspergillus species from respiratory secretions has low diagnostic sensitivity. Assays to detect Aspergillus antigen or DNA in bronchoalveolar lavage (BAL) fluid could facilitate earlier diagnosis, thereby guiding optimal therapy and obviating the need for additional costly and potentially morbid diagnostic evaluation. We evaluated the performance of a galactomannan enzyme immunoassay (GM EIA; Bio-Rad) by using a range of index cutoffs to define positivity and a quantitative PCR (qPCR) assay for the detection of Aspergillus species from BAL samples of patients with proven and probable IPA (case patients; n = 49) and without IPA (control patients; n = 50). The sensitivity of the GM EIA was 61% with an index cutoff of 1.0 and 76% with an index cutoff of 0.5; the corresponding specificities were 98 and 94%, respectively. The sensitivity and specificity of qPCR assay were 67 and 100%, respectively. The sensitivity with 22 culture-negative BAL specimens from patients with IPA was 41% for GM EIA with an index cutoff of 1.0, 59% for GM EIA with an index cutoff of 0.5, and 36% for qPCR assay. GM EIA indices and DNA quantities corresponded to BAL fungal burdens, with culture-positive samples having larger amounts of antigen and DNA compared to culture-negative samples. GM EIA and qPCR assay add to the sensitivity of BAL for diagnosing IPA in high-risk patients, with excellent specificity. Adjunctive use of these tests may reduce dependence on invasive diagnostic procedures.

Aspergillosis↗
PubMed1999

Interpreting validity indexes for diagnostic tests: an illustration using the Berg balance test.

Physical therapists routinely make diagnostic and prognostic decisions in the course of patient care. The purpose of this clinical perspective is to illustrate what we believe is the optimal method for interpreting the results of studies that describe the diagnostic or prognostic accuracy of examination procedures. To illustrate our points, we chose the Berg Balance Test as an exemplar measure. We combined the data from 2 previously published research reports designed to determine the validity of the Berg Balance Test for predicting risk of falls among elderly people. We calculated the most common validity indexes, including sensitivity, specificity, predictive values, and likelihood ratios for the combined data. Clinical scenarios were used to demonstrate how we believe these validity indexes should be used to guide clinical decisions. We believe therapists should use validity indexes to decrease the uncertainty associated with diagnostic and prognostic decisions. More studies of the accuracy of diagnostic and prognostic tests used by physical therapists are urgently needed.

Accidental Falls↗
PubMed2004

Development of the Korean version of the Geriatric Depression Scale and its short form among elderly psychiatric patients.

OBJECTIVE: The aim of this study was to evaluate the diagnostic validity of the Korean version of the Geriatric Depression Scale (GDS-K) and its short form among elderly psychiatric patients. METHOD: After three preliminary trials, the authors translated the GDS, including the Geriatric Depression Scale-Short Form (SGDS) into Korean. The GDS-K, the Korean version of the SGDS (SGDS-K), Hamilton Rating Scale for Depression (HRS-D), and the Center for Epidemiologic Studies Depression Scale (CES-D) were administered to 154 elderly psychiatric patients. In addition, the Diagnostic Interview Schedule (DIS-III-R) was administered independently to diagnose DSM-III-R major depression. Reliability and validity test, optimal cutoff point estimation, and receiver operating characteristics (ROC) curve analysis were performed to investigate the diagnostic validity of the GDS-K and SGDS-K. RESULTS: Internal consistency-reliability and concurrent validity of the GDS-K and SGDS-K associated with other depression scales (HRS-D, CES-D) were excellent. Content validity and discriminant validity, which differentiate DSM-III-R major depression from nonmajor depression was also good. We suggest a score of 16 as the optimal cutoff point of GDS-K for screening DSM-III-R major depression among clinical populations and a score of 8 as optimal cutoff score of SGDS-K. ROC curve analysis indicated high diagnostic validity for both GDS-K and SGDS-K in assessing DSM-III-R major depression. Moreover, we found that the GDS-K and SGDS-K were highly correlated (r=.9522). This finding suggests that the SGDS-K can be used as an adequate substitute for the GDS-K. CONCLUSION: The GDS-K and SGDS-K proved valid and reliable case-finding tools for screening DSM-III-R major depression among the elderly psychiatric patients in Korea. The relatively high cutoff points of both the GDS-K and SGDS-K require further evaluation from the viewpoint of culturally determined response style in elderly Koreans.

Aged↗
PubMed2002

Alphaherpesvirus antigen quantitation to optimize the diagnosis of herpes B virus infection.

Standardized, quantified virus antigen stocks are essential for dependable quality control of diagnostic assays. Five simple, rapid and economical direct enzyme linked immunoassays (dELISA) were developed to standardize and optimize antigen from five major cross-reacting alphaherpesviruses: herpes B virus, herpesvirus papio 2, langur monkey herpesvirus, herpes simplex virus-1 and herpes simplex virus-2. Each dELISA relied on pools of convalescent sera from rhesus monkeys, baboons, langurs and humans. Conjugates were prepared from purified IgG preparations, fractionated from the same sera and then labeled with peroxidase. Serum coated microplates could be stored at -70 degrees C for at least 1 year before use. The duration of the test was approximately 2.5 h if plates were prepared at an earlier time. Virus antigen titers could be determined from titration curves or from single dilutions using a standard curve. The sensitivity of detection was approximately 8x10(5) PFU/ml. This sensitivity sufficed for the determination of viral antigen mass in live or detergent treated virus stocks that usually contain at least 1x10(8) PFU/ml. The assays were valuable for quality assurance of diagnostic serological assays for herpes B virus and other alphaherpesviruses.

Alphaherpesvirinae↗
PubMed1996

Hoffa fracture--a radiologic diagnostic approach.

Hoffa fracture is a rare injury consisting of unicondylar tangential posterior fracture of the distal femur. On plain radiographs the fracture line is clearly seen. However, some fractures and musculotendinous injuries may display subtle features and may be difficult to detect even with optimal images. We explain the mechanism of injury, discuss the diagnostic work-up and the operative and nonoperative management.

Adult↗
PubMedDate not supplied

[Optimization of RT-PCR for the identification of VP4 gene of group A rotaviruses and evaluation of its diagnostic efficiency].

A method is suggested for the detection of the human rotavirus VP4 gene by RT-PCR. The method is universal for all [P] types of group A rotavirus in clinical samples. As against RNA electrophoresis and ELISA, it provides for a more accurate detection of rotaviruses by 18.8 and 26.5%, respectively. It was established by RT-PCR in February, 2002, in Nizhny Novgorod, that rotaviruses were responsible for 67% of acute gastroenteritis in hospitalized children.

Capsid Proteins↗
PubMed1999

Field strength and dose dependence of contrast enhancement by gadolinium-based MR contrast agents.

The relaxivities r1 and r2 of magnetic resonance contrast agents and the T1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R1 = 1/T1 and R2 = 1/T2) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields.

Brain↗
PubMedDate not supplied

[Systems approach to the development of equipment provision for roentgenological research].

A systemic approach to the X-ray out fits allowed 3 levels of the roentgen-diagnostic process to be singled out, viz. the lower with the data the data "normally--anormality", the medium, with a tentative conclusion and the highest, with an authentic diagnosis at the output end. The levels may be characterized by formulas reflecting the number of inputs, processes (methods) and outputs. The optimal roentgenological facilities should be in keeping with the diagnostic levels formulas. The prospects for improving the facilities involve a systemic approach to the development of equipment and an integration on this basis of the investigation methods, both horizontally (within the framework of roentgenology) and vertically (outside roentgenology).

Electrodiagnosis↗
PubMed2004

Imaging for neuro-ophthalmic and orbital disease.

PURPOSE: To provide an update on imaging of the brain and orbit for ophthalmologists. DESIGN: Literature review. METHODS: A systematic English-language medline search and summary of recent literature on imaging of brain and orbit was performed. RESULTS: Computed tomography and magnetic resonance (MR) scanning are the mainstays for the evaluation of most disorders involving the brain and orbit. Computed tomography angiography and magnetic resonance angiography are relatively newer applications that are useful for the evaluation of arterial and venous disorders. Special sequences such as fat suppression and fluid attenuation inversion recovery are useful techniques for specific ophthalmic indications. Diffusion weighted imaging and perfusion-weighted imaging are improving the evaluation of acute stroke. Functional MRI, positron emission tomography scanning and single photon emission computed tomography may provide useful information regarding brain or tumor metabolism. Magnetic resonance spectroscopy has expanded our knowledge of brain function. Newer imaging studies have improved our diagnostic abilities on many fronts, including new sequences, new applications of imaging studies, and functional imaging of brain. CONCLUSION: New imaging techniques for brain and orbit have an increased potential for improving diagnostic yield. Accurate and timely communication with the neuroradiologist can optimize the prescription and interpretation of imaging in ophthalmology.

Brain Diseases↗
PubMed1978

Clinicians, the Mount Sinai program and the Veterans' Administration program evaluated against clinico-pathological data derived independently of the electrocardiogram.

221 electrocardiograms (ECGs) recorded from adult subjects with cardiac symptomatology were interpreted by clinicians and the Mount Sinai (MS) and Veterans' Administration (VA) computer programs. After the clinicians had eliminated their interobserver variability, their interpretations and those of the computer programs were compared with the corresponding clinico-pathological data that had been derived independently of the ECG. A measure of overall diagnostic accuracy was used which showed that the performance of the 2 computer programs was similar and somewhat worse than that of the clinicians. The clinicians and the computer programs were not as good at diagnosing the ECGs of women as at diagnosing those of men. As the VA program's interpretations may be altered by including information about the patient's provisional diagnosis, 6 different sets of these prior probabilities were used to analyse 141 of the original 221 ECGs. Different fixed sets of prior probabilities made only a small difference to overall diagnostic accuracy but a marked difference to the VA program's ability to differentiate Normal from Abnormal. Optimizing the prior probabilities for the individual subjects increased the VA program's overall diagnostic accuracy up to that of the clinicians. Both computer programs correctly diagnosed sinus rhythm as the dominant rhythm in 165 out of 177 subjects. The MS program diagnosed the dominant rhythm as Atrial Fibrillation in 35 out of 41 subjects and the VA program in 27 (X(2) = 3.24; not significant). ECG interpretation; Mount Sinai program; Veterans' Administration program; independent clinico-pathological data; sex differences in the ECG; prior probabilities.

Adult↗
PubMed1989

Optimizing radiologic workup: an artificial intelligence approach.

The increasing complexity of diagnostic imaging is presenting an ever expanding variety of radiologic test options to clinicians. As a result, it is becoming more difficult for referring physicians to select an appropriate sequence of tests. The current economic pressures on medicine make it particularly important that resources be used judiciously. Radiologic workup often involves a sequence of tests that lead from presenting signs and symptoms to a definitive diagnosis or intervention. This sequence ideally begins with simple, inexpensive, safe, non-invasive tests and progresses to more complex, expensive, and hazardous tests only if the simpler tests are insufficient to establish a diagnosis. DxCON is a developmental artificial intelligence-based computer system that gives advice to physicians about the optimum sequencing of radiologic tests. DxCON evaluates basic clinical information and a physician's proposed workup plan. The system then creates an analysis of the strengths and weaknesses of his plan. The domain chosen to explore computer-based workup advice is the radiologic workup of obstructive jaundice.

Cholestasis↗
PubMed2000

Detection of prostate cancer: a comparative study of the diagnostic efficacy of sextant transrectal versus sextant transperineal biopsy.

OBJECTIVES: The optimal biopsy strategy for the detection of prostate cancer still needs to be established, since a considerable proportion of clinically significant cancers remains undiagnosed on routine sextant transrectal biopsy. To assess the efficacy of transperineal biopsy to detect prostate cancer, we compared this approach to systematic sextant transrectal biopsy in a simulation experiment. METHODS: Ultrasound-guided sextant transverse (transrectal) biopsy and subsequent sextant longitudinal (transperineal) biopsy were performed on 40 radical prostatectomy specimens of patients with (transrectal) biopsy-detected prostate cancer. Conditions were simulative and may not be completely analogous to clinical settings. Ultrasound-determined prostate volume, biopsy tumor involvement, number of cores with cancer, and tumor volume were determined. Detailed mapping of radical prostatectomy specimens provided insight into the representativeness of the biopsy techniques. RESULTS: Of 40 cancers, 33 (82.5%) were redetected by the transperineal approach; 29 (72.5%) were detected by repeated transrectal biopsies. For both approaches, the tumor volume of the undiagnosed cancers was significantly smaller (P <0.01) and the prostate volume was significantly larger (P <0.01) than in the redetected ones. Between the two approaches, no difference was found for either of the variables determined in the redetected cancers. Prostate maps clarified that transperineal undiagnosed tumors were either small (0.2 cm(3) or less) or notably located at the prostatic base. CONCLUSIONS: The biopsy procedure in which the biopsy needles enter the prostate at the apex for a longitudinal direction may efficiently sample the prostatic peripheral zone. Since the experiment was artificial in design, caution should be observed in extrapolating these results to patient settings.

Biopsy↗
PubMed2001

Diagnostic validity of computed tomography for mediastinitis after cardiac surgery.

BACKGROUND: Optimal treatment based on appropriate early diagnosis is essential in managing mediastinitis after cardiac surgery. We evaluated the accuracy of thoracic computerised tomography (CT) in the diagnosis of mediastinitis. METHODS: Forty-one patients in whom we performed CT after cardiac surgery were classified into two groups as follows; Six cases had mediastinitis requiring a redo surgical intervention (Group M). Thirty-five cases recovered without mediastinitis (Group C). Comparisons of CT findings in both groups were made retrospectively. RESULTS: In group M, CT and re-operations were performed 6.3+/-2.5 days and 8.0+/-5.2 days after previous operation, respectively. All but one of redo surgical procedures were mediastinal lavage and omental transplantation. Two patients died due to septic shock and multiple organ failure. CT in group M showed a soft tissue mass with contrast enhancement in 4 patients, bilateral pleural effusion in 5, free gas appearance in 4, and sternal dehiscence or destruction in 2 patients. Consequently, we regarded 4 of the 6 patients in this group as showing postoperative mediastinitis radiographically. In group C, CT performed 16.6+/-7.1 days after operations revealed findings suggestive of mediastinitis in 6 patients. Therefore, in terms of the validity of CT for the diagnosis of mediastinitis, the sensitivity was 67% and the specificity was 83%. CONCLUSION: The sensitivity of CT for diagnosis of mediastinitis after cardiac operations is unsatisfactory. Diagnosis by seeking infective changes in a multidisciplinary way is important in dealing with mediastinitis.

Aged↗
PubMedDate not supplied

[Aluminum and uremic bone disease. Diagnostic utility of serum aluminum and the deferoxamine (DFO) test ].

The optimal control of aluminium content in dialysis fluids has resulted in a decrease in the incidence of aluminium related bone disease (ARBD) and in the risk for aluminium toxicity. Nevertheless the problem has not disappeared. Bone biopsy with specific staining for Al remains the only reliable method for the diagnosis of ARBD. Currently there is not a total agreement on the reliability of serum Al levels and of the DFO test in the identification of patients with Al overload or toxicity. In a series of patients (mean age 48 +/- 14 years old) from our hemodialysis units we carried out bone biopsy and we studied the prevalence of bone aluminium overload and of ARBD and the usefulness of serum aluminium and of DFO test in their diagnosis. Seventy- three bone biopsies were evaluated by histomorphometric analysis and aluminium staining (Aluminon). Al overload was diagnosed when the Aluminon staining was positive independent of the bone surface covered with Al and of the bone formation rate (BFR). Patients were consider to have ARBD when aluminium covered > 25% of bone surface and BFR was < 0.031 micron 3/micron 2/day. Fifteen patients had aluminium overload while 7 patients were considered to have ARBD. Positive Aluminon staining appeared in all histopathological forms of renal osteodystrophy although it appeared mainly in patients with mixed lesion and osteomalacia. Most of the patients with adynamic bone disease had negative Aluminon staining. Patients with aluminium overload showed lower bone formation and mineralization rates. Serum aluminium levels below 40 micrograms/l were useful to exclude bone aluminium overload. Serum aluminium levels and DFO test were not specific in diagnosing aluminium overload or ARBD. A DFO test with an increment in serum aluminium over 100 micrograms/l in combination with a serum PTH below 200 pg/ml was useful to diagnose ARBD.

Adult↗
PubMedDate not supplied

[Further studies of continuous human and animal cell lines for the manufacture of viral vaccines and diagnostic kits].

Long-term experiments have provided conditions for the optimal conditions for reproduction of vaccine strains of poliomyelitis, measles, tick-borne and Japan encephalitis on the continuous cell lines. This makes it possible to solve one of the most urgent problems of modern biotechnology, namely to refuse to use primary cell cultures in vaccinology and to apply a more accessible, safe, and reference biological substrate that are stable cell lines.

Animals↗
PubMed1977

A nonlinear model for predicting radiographic contrast.

A computerized model has been developed which permits ideal maximum radiographic contrast, associated with clinically meaningful changes in x-ray attenuation for any combination of tissues, to be predicted from the spectral energy of the primary beam and the characteristics of the film. Results suggest that these factors influence available contrast in ways which depend on the specific diagnostic task to be accomplished. Hence, it appears that no single technique is optimal for all tissue configurations. Although contrast computed in this way does not take into account other factors of diagnostic interest, such as image resolution and context-dependent cues to lesion identity, it is an independent factor which can profoundly influence the detectability of specific changes in tissue attenuation and, as such, it may be considered a reasonable basis for predicting diagnostic performance.

Computers↗
PubMed2005

Diagnosis of biliary strictures after liver transplantation: which is the best tool?

AIM: To evaluate the diagnostic value of different indirect methods like biochemical parameters, ultrasound (US) analysis, CT-scan and MRI/MRCP in comparison with endoscopic retrograde cholangiography (ERC), for diagnosis of biliary complications after liver transplantation. METHODS: In 75 patients after liver transplantation, who received ERC due to suspected biliary complications, the result of the cholangiography was compared to the results of indirect imaging methods performed prior to ERC. The cholangiography showed no biliary stenosis (NoST) in 25 patients, AST in 27 and ITBL in 23 patients. RESULTS: Biliary congestion as a result of AST was detected with a sensitivity of 68.4% in US analysis (specificity 91%), of 71% in MRI (specificity 25%) and of 40% in CT (specificity 57.1%). In ITBL, biliary congestion was detected with a sensitivity of 58.8% in the US, 88.9% in MRI and of 83.3% in CT. However, as anastomotic or ischemic stenoses were the underlying cause of biliary congestion, the sensitivity of detection was very low. In MRI detected the dominant stenosis at a correct localization in 22% and CT in 10%, while US failed completely. The biochemical parameters, showed no significant difference in bilirubin (median 5.7; 4,1; 2.5 mg/dL), alkaline phosphatase (median 360; 339; 527 U/L) or gamma glutamyl transferase (median 277; 220; 239 U/L) levels between NoST, AST and ITBL. CONCLUSION: Our data confirm that indirect imaging methods to date cannot replace direct cholangiography for diagnosis of post transplant biliary stenoses. However MRI may have the potential to complement or precede imaging by cholangiography. Optimized MRCP-processing might further improve the diagnostic impact of this method.

Adult↗