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PubMed2003

Optimal choice of a cut point for a quantitative diagnostic test performed for research purposes.

Often, in epidemiologic research, classification of study participants with respect to the presence of a dichotomous condition (e.g., infection) is based on whether a quantitative measurement exceeds a specified cut point. The choice of a cut point involves a tradeoff between sensitivity and specificity. When the classification is to be made for the purpose of estimating risk ratios (RRs) or odds ratios (ORs), it might be argued that the best choice of cut point is one that maximizes the precision of estimates of the RRs or ORs. In this article, two different approaches for estimating RRs and ORs are discussed. For each approach, formulae are derived that give the mean squared error of the RR and OR estimates, for any choice of cut point. Based on these formulae, a cut point can be chosen that minimizes the mean squared error of the estimate of interest.

Diagnostic Tests, Routine↗

PubMed2001

Digital image documentation for quality assessment.

OBJECTIVE: To demonstrate the feasibility of the use of digital images to document routine cases and to perform diagnostic quality assessment. METHODS: Pathologists documented cases by acquiring up to 12 digital images per case. The images were sampled at 25:1, 50:1, 100:1, 200:1, or 400:1 magnifications, according to adequacy in aiding diagnosis. After each acquisition, the referral pathologist marked a region of interest within each acquired image in order to evaluate intrinsic redundancy. The extrinsic redundancy was determined by counting the unnecessary images. Cases were randomly selected and reviewed by one pathologist. The quality of each image, the possibility of accomplishing a diagnosis based on images, and the degree of agreement was evaluated. RESULTS: During routine practice, 1469 cases were documented using 3902 images. Most of the images were acquired at higher power magnifications. From all acquired cases, 143 cases and their 373 related images were randomly selected for review. In 88.1% (126/143) of reviewed cases, it was possible to accomplish the diagnosis based on images. In 30.2% (38/126) of these cases, the reviewer considered that the diagnosis could be accomplished with fewer images. The referral pathologist and the reviewer found intrinsic redundancy in 57.8% and 54.5% of images, respectively. CONCLUSIONS: Our results showed that digital image documentation to perform diagnostic quality assessment is a feasible solution. However, owing to the impact on routine practice, guidelines for acquisition and documentation of cases may be needed.

Diagnosis↗

PubMed2004

Improved characterization of liver lesions with liver-phase uptake of liver-specific microbubbles: prospective multicenter study.

PURPOSE: To evaluate in a prospective multicenter study whether conventional ultrasonographic (US) characterization of liver lesions can be improved by imaging during the liver-specific phase of SH U 508A uptake in the microbubble-specific agent detection imaging mode. MATERIALS AND METHODS: One hundred forty-two patients with liver lesions underwent conventional gray-scale and color Doppler US and SH U 508A-enhanced US. Two radiologists blindly read digital cine clips and assigned scores for confidence in diagnosis of benignancy or malignancy, diagnosis of specific lesion types, and relative difference in SH U 508A uptake between the lesion and the liver parenchyma (ie, subjective conspicuity score [SCS]). Comparisons were made to see whether the addition of agent detection imaging led to improved diagnostic performance. RESULTS: Receiver operating characteristic analysis revealed improved discrimination of benign and malignant lesions for readers 1 (P =.049) and 2 (P <.001). The number of patients with a correct diagnosis of benignancy or malignancy assigned by readers 1 and 2, respectively, improved from 114 and 113 to 125 and 128 with agent detection imaging (reader 1: P =.027; reader 2: P =.008; McNemar test). Specific diagnoses were made more accurately with agent detection imaging: At McNemar testing, the number of correct lesion type determinations increased from 83 to 92 (P =.022) for reader 1 and from 85 to 99 (P <.001) for reader 2. Both readers assigned high scores for differences in SH U 508A uptake between the liver parenchyma and the lesion for metastases and cholangiocarcinomas and low scores for uptake differences in most of the benign lesions. Hepatocellular carcinomas (HCCs), hemangiomas, and adenomas had more variable uptake differences. Fourteen of 22 hemangiomas were assigned an SCS of less than 50%, and 22 (reader 1) and 15 (reader 2) of 31 HCCs were assigned an SCS of greater than 50%. CONCLUSION: With use of SH U 508A-enhanced agent detection imaging, liver lesion characterization and diagnostic performance are significantly improved.

Adult↗

PubMed2000

Detection of specific antibodies to pigeon serum and bloom antigens by enzyme linked immunosorbent assay in pigeon breeder's disease.

BACKGROUND: Pigeon breeder's disease is an extrinsic allergic alveolitis in the lungs of sensitised people, caused by hypersensitivity reactions to inhaled pigeon antigens. Antigens from different sources of the animal are used for diagnostic purposes, with serum being the most widely used. Bloom is rarely used; very little is known of its antigenicity and diagnostic performance, particularly when used with the enzyme linked immunosorbent assay (ELISA) method, which is the most popular test as it permits measurement of the antibody response. METHODS: To (a) standardise an ELISA for the measurement of specific IgG against pigeon serum and pigeon bloom extract; (b) to establish reference values for specific IgG in 73 non-exposed controls, (c) to show the presence of specific IgG against pigeon serum and bloom in serum samples of 17 patients with bird fancier's lung and 11 asymptomatic fanciers, and (d) to study the similarity of the two antigen sources by cross reactivity experiments. RESULTS: Reference values of specific IgG were defined with the 97.5 percentile (367.9 U/ml for pigeon serum and 953.7 U/ml for pigeon bloom extract). Of symptomatic patients 100% had values higher than the cut off for both antigens. In asymptomatic fanciers values were higher than the cut off for pigeon serum in 45% and bloom extract in 54%. Cross reactivity experiments showed that the two antigens differed in antigenic content although some components may be common to both. CONCLUSION: The ELISA methods used proved to be useful tools for evaluating specific IgG antibody responses against both antigens. The diagnostic performance of both ELISA methods performed with these antigen sources was similar, showing very high sensitivity but moderate specificity. Although some antigenic similarity was found between pigeon serum and bloom extract, cross reactivity studies showed that various antigens seemed to be specific to the bloom extract. However, the antigens responsible for pigeon breeder's disease seem to be present in both antigenic sources.

Adult↗

PubMed2006

Computer-assisted evaluation of perianal fistula activity by means of anal ultrasound in patients with Crohn's disease.

OBJECTIVES: Assessment of the activity of perianal fistulas may be of clinical relevance in patients with Crohn's disease. Fistula activity is currently evaluated by means of magnetic resonance imaging; anal ultrasound can also be used, but its diagnostic performance in this setting remains to be defined. Our aims were to evaluate the agreement between clinical examination, magnetic resonance imaging, and anal ultrasound in assessing perianal fistula activity, and to apply computerized analysis to improve the assessment of ultrasound images. METHODS: Thirty-one consecutive patients with Crohn's perianal fistulas underwent clinical examination, and magnetic resonance and anal ultrasound imaging. Active fistulas were defined as the presence of active drainage or signs of local inflammation on clinical examination, and the definition was confirmed by surgical examination. Activity was assessed on the basis of T2 hyperintensity on magnetic resonance imaging and the degree of hypoechogenicity on anal ultrasound; the anal ultrasound images were also analyzed using dedicated computer image-analysis software. RESULTS: Twenty-five patients had an active fistula at clinical examination. The agreement between clinical examination and magnetic resonance imaging was good (k-value = 0.739), whereas that with anal ultrasound was only fair (k-value = 0.266-0.294); computer-assisted analysis of the anal ultrasound images improved the agreement from fair to good (k-value = 0.608-0.670). CONCLUSIONS: Anal ultrasound can be used to assess fistula track activity in patients with Crohn's disease. The diagnostic performance of the technique can be improved to values comparable with those of magnetic resonance imaging by using a computer-assisted evaluation of the anal ultrasound images.

Adult↗

PubMed2006

Gluc-Lys([18F]FP)-TOCA PET in patients with SSTR-positive tumors: biodistribution and diagnostic evaluation compared with [111In]DTPA-octreotide.

UNLABELLED: A recently developed (18)F-labeled PET tracer for somatostatin receptor (sstr) imaging, N(alpha)-(1-deoxy-D-fructosyl)-N(epsilon)-(2-[(18)F]fluoropropionyl)-Lys(0)-Tyr(3)-octreotate (Gluc-Lys([(18)F]FP)-TOCA), was evaluated in patients with sstr-positive tumors by assessing the pharmacokinetics, biodistribution, and diagnostic performance in comparison with [(111)In]DTPA-octreotide. METHODS: Twenty-five patients with different sstr-positive tumors were included in the study and were injected with 105 +/- 50 MBq Gluc-Lys([(18)F]FP)-TOCA. PET was performed up to 120 min with 2 different dynamic imaging protocols. Tracer kinetics in tumors and nontumor tissues and tumor-to-background ratios were described by region-of-interest analysis and standardized uptake values (SUVs). In 16 patients, sstr scintigraphy with [(111)In]DTPA-octreotide was performed (whole-body scans and SPECT). Two independent experts on PET and gamma- camera scans performed lesion counts. RESULTS: Gluc-Lys([(18)F]FP)-TOCA showed a fast and intense tumor accumulation as well as a rapid clearance from blood serum (biexponential elimination, with the half-lives of the initial and the terminal elimination phase calculated as t(1/2)(1) = 2.3 +/- 1.3 min and t(1/2)(2) = 26.4 +/- 14.6 min, respectively). Tumor-to-background ratios at 16 +/- 9 min and 34 +/- 12 min were as high as 80% and 90% (% of maximum ratios), respectively. Tumors showed high SUVs ranging from 13.7 +/- 2.3 (tumors in lung) up to 26.9 +/- 15.4 (abdominal tumors). Tracer distribution within tumor and nontumor tissues was stable up to 120 min (except spleen). No significant bowel activity was observed. Comparison of 29 tumors located in the liver showed a mean tumor-to-background ratio of 5.3 +/- 2.6 for Gluc-Lys([(18)F]FP)-TOCA vs. 4.6 +/- 3.3 for [(111)In]DTPA-octreotide (P = 0.24). Visual image analysis revealed a significantly higher number of lesions (factor of 2.4) and improved interobserver correlation (r = 0.99 vs. 0.86) for PET. CONCLUSION: Gluc-Lys([(18)F]FP)-TOCA PET allows a fast, high- contrast imaging of sstr-positive tumors. The biokinetics and diagnostic performance of Gluc-Lys([(18)F]FP)-TOCA are superior to [(111)In]DTPA-octreotide and-as far as can be derived from the literature-comparable with [(68)Ga]-DOTA-d Phe(1)-Tyr(3)-octreotide ([(68)Ga]DOTATOC).

Adult↗

PubMed2005

The validity of screening based on spot morning urine samples to detect subjects with microalbuminuria in the general population.

BACKGROUND: No study has yet investigated the validity of prescreening by albumin measurements in a spot morning urine sample to identify in the general population subjects with microalbuminuria. We therefore tested the diagnostic performance of urinary albumin concentration (UAC) and albumin-creatinine ratio (ACR), measured in a spot morning urine sample, in predicting a urinary albumin excretion (UAE) > or =30 mg in subsequent 24-hour urines (microalbuminuria). METHODS: Subjects (2527) participating in the PREVEND study, a representative sample from the general population, collected a spot morning urine sample and, on average, 77 days later, two 24-hour urine collections. RESULTS: The ROC curve of UAC in predicting microalbuminuria has an area-under-the-curve of 0.92 with a discriminator value of 11.2 mg/L. Using this cut-off value for UAC, sensitivity in predicting microalbuminuria is 85.0%, and specificity 85.0%. For ACR these values are, respectively: area-under-the-curve 0.93, discriminator value 9.9 mg/g, sensitivity 87.6%, and specificity 87.5%. Sensitivity for UAC in predicting microalbuminuria does not differ significantly from the sensitivity for ACR, whereas the difference between the specificities of UAC and ACR reaches statistical significance, but is numerically very small. In various subgroups characterized by differences in urinary creatinine excretion, the area-under-the-ROC curve, sensitivity, as well as specificity, do not increase relevantly compared to the results in the overall study population. This holds true for ACR as well as UAC. CONCLUSION: The diagnostic performance of measuring UAC in a spot morning urine sample in predicting microalbuminuria in subsequent 24-hour urine collections is satisfactory, and, moreover, comparable to that of measuring ACR. In order to keep the burden and costs involved in population screening for microalbuminuria as low as possible, we therefore propose prescreening by measuring UAC in a spot morning urine sample. Those subjects with a UAC above a certain predefined level (e.g., 11 mg/L) should be asked to collect timed urine samples.

Adult↗

PubMed2026

PCa Detection in PI-RADS 4 and 5 Lesions: Comparison of [68Ga]Ga-PSMA-11 PET/CT-Guided Robot-Assisted Biopsy Versus mpMRI Cognitive-Fusion TRUS-Guided Prostate Biopsy.

Lesions with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 4 or greater on multiparametric MRI (mpMRI) indicate a high likelihood of prostate cancer (PCa), and guidelines recommend a targeted biopsy. We aimed to compare the diagnostic performance of robotic arm-assisted [68Ga]Ga-PSMA-11 PET/CT-guided prostate biopsy (PGPB) with mpMRI-directed cognitive-fusion transrectal ultrasound-guided biopsy (MCFB) in biopsy-naïve men with clinical findings suggestive of PCa. Methods: This prospective, single-center, randomized clinical trial (NCT05137561) enrolled biopsy-naïve men age 50-90 y with elevated levels of prostate-specific antigen (≥4 ng/mL) and abnormal digital rectal examination findings. All participants underwent mpMRI, and those with a PI-RADS score of 4 or greater were randomized into 2 arms. In arm 1, participants underwent PGPB for a [68Ga]Ga-PSMA-avid lesion, and participants in arm 2 underwent MCFB. Participants in arm 1 with PET-negative findings subsequently underwent MCFB, and participants with negative biopsy results underwent PET and PGPB. The primary outcome was the detection of PCa. Secondary outcomes included complication rates and participant-reported pain. Result: Of the 267 participants enrolled, 81.3% (217) had lesions with a PI-RADS score of 4 or greater and were randomized to either PGPB (n = 112) or MCFB (n = 105). PCa was detected in 97.1% of participants (101/104) in arm 1 and 81.0% (85/105) in arm 2 (P < 0.05). PGPB showed higher diagnostic accuracy for PI-RADS 5 lesions (100% vs. 95.1%, P = 0.09). Major complications were observed in arm 2 only (n = 5). Arm 1 had significantly fewer complications (10.8% vs. 51.4%, P < 0.01), a lower median visual analog scale score for pain (3 vs. 5), and shorter procedure times. The core positivity rate was higher in arm 1 (60% ± 20%), despite obtaining fewer cores. Conclusion: [68Ga]Ga-PSMA-11 PGPB demonstrated higher diagnostic performance, fewer complications, and better tolerability compared with MCFB. This approach enables integrated diagnosis and staging, offering a promising alternative for efficient, safe, and accurate evaluation of prostate cancer.

Humans↗

PubMed1997

Effect of exposure time on in vitro caries diagnosis using the Digora system.

The aim of this study was to determine the in vitro diagnostic performance for approximal caries and occlusal dentine caries diagnosis of the Digora system for digital radiography in relation to the exposure time. Radiographs were made of 220 extracted human posterior teeth and cuspids at exposure time levels of 3%, 6%, 10%, 20%, and 78% of the exposure time needed for E-speed film (image sets I, II, III, IV, and V, respectively). The image sets were put in random order (III, I, IV, II, V) and assessed independently by 3 observers using a 5-point confidence scale. True caries status was determined histologically after sectioning of the teeth. Evaluated parameters were: interexaminer kappa, sensitivity, specificity, Dz3/4 (the distance of one operating point to the diagonal in the ROC domain) and area under the ROC curve. The Spearman correlation coefficients between the parameters and both exposure time and order of viewing of the sets were calculated. For approximal surfaces, the ranges of mean parameter values were: sensitivity 26-33%, specificity 93-95%, Dz3/4 0.63-0.84, area 0.61-0.69. For occlusal surfaces, the ranges were: sensitivity 52-60%, specificity 91-95%, Dz3/4 1.03-1.34, area 0.79-0.87. Out of 24 pairwise comparisons between sets V and I, 5 were significant. Out of 24 comparisons between set V and II, only 2 were significant. It was concluded that diagnostic performance is unlikely to be impaired for an exposure time as short as 6% of E-speed film exposure. When reducing the exposure time to 3% of E-speed film exposure, caries diagnosis may be impaired.

Bicuspid↗

PubMed2004

Detection of coronary artery disease by magnetic resonance myocardial perfusion imaging with various contrast medium doses: first European multi-centre experience.

AIMS: Magnetic resonance (MR) first-pass myocardial perfusion imaging during hyperaemia detects coronary artery stenoses in humans with test sensitivity depending on contrast medium (CM)-induced signal change in myocardium. In this prospective multi-centre study, the effect of CM dose on myocardial signal change and on diagnostic performance was evaluated using a stress-only approach. METHODS AND RESULTS: Ninety-four patients with known or suspected coronary artery disease (CAD) were randomised to 0.05,0.10, or 0.15 mmol/kg body weight of an extravascular CM (Gd-DTPA) and X-ray coronary angiography was performed within 30 days prior/after the MR examination. A multi-slice MR technique with identical hardware and software in all centres was used during hyperaemia (adenosine 0.14 mg/kg/min) to monitor myocardial CM wash-in kinetics and data were analysed semi-automatically in a core laboratory. Protocol violations resulted in 80 complete studies with CAD (defined as > or =1 vessel with diameter stenosis > or =50% on quantitative coronary angiography) present in 19/29, 13/24, and 20/27 patients for doses 1, 2, and 3, respectively. In normal myocardium, the upslope increased with CM dose (overall-p<0.0001, ANOVA). For CAD detection the area under the receiver operator characteristics curve for subendocardial data (3 slices with quality score<4 representing 86% of cases) was 0.91+/-0.07 and 0.86+/-0.08 for doses 2 and 3, respectively, and was lower for dose 1 (0.53+/-0.13, p<0.01 and p<0.02 vs. doses 2 and 3, respectively). Corresponding sensitivities/specificities (95% confidence intervals) for pooled doses 2/3 were 93% (77-99%; ns vs. dose 1) and 75% (48-92%;p<0.05 vs. dose 1), respectively. CONCLUSIONS: With increasing doses of CM, a higher signal response in the myocardium was achieved and consequently this stress-only protocol, with CM doses of 0.10-0.15 mmol/kg combined with a semi-automatic analysis, yielded a high diagnostic performance for the detection of CAD.

Analysis of Variance↗

PubMed2000

Limited incremental diagnostic values of attenuation-noncorrected gating and ungated attenuation correction to rest/stress myocardial perfusion SPECT in patients with an intermediate likelihood of coronary artery disease.

UNLABELLED: Either gated myocardial perfusion SPECT or attenuation-corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease (CAD). We investigated whether attenuation-noncorrected gating and ungated attenuation correction could improve the diagnostic performance of rest/stress perfusion SPECT in patients having an intermediate pretest likelihood of CAD. METHODS: Sixty-eight patients (29 men, 39 women; mean age, 59 +/- 12 y) with coronary artery stenosis > or =70% (1 vessel, n = 13; 2 vessels, n = 18; 3 vessels, n = 8; normal, n = 29) underwent rest attenuation-corrected 201TI SPECT and dipyridamole stress gated attenuation-corrected 99mTc-methoxyisobutyl isonitrile SPECT with an ADAC vertex camera. Three physicians graded the post-test likelihood of CAD for each arterial territory using a 5-point scale (1, normal; 2, possibly normal; 3, equivocal; 4, possibly abnormal; 5, abnormal). The sensitivity, specificity, and areas under receiver-operating-characteristic curves were compared for each operator by 3 methods: attenuation-noncorrected rest/stress SPECT, gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT, and attenuation-corrected rest/stress SPECT plus gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT. RESULTS: When higher than grade 3 was used as the criterion for CAD, no differences in sensitivity and specificity were found among the 3 methods for each operator. Areas under receiver-operating-characteristic curves for the diagnosis of CAD and stenosis revealed no differences for each modality (P > 0.05 for each comparison). CONCLUSION: In patients with an intermediate risk of CAD, viewing attenuation-noncorrected gated poststress SPECT and ungated attenuation-corrected rest/stress SPECT images did not improve the diagnostic performance for CAD and stenosis.

Coronary Circulation↗

PubMed2006

Screening for high-grade carotid stenosis using a portable ultrasonography instrument.

BACKGROUND AND PURPOSE: We investigated the diagnostic performance of a brief Power Doppler Imaging (PDI) screening examination for carotid artery stenoses using a newly developed portable instrument. METHODS: A highly experienced sonographer screened in total 152 carotid arteries by either continuous wave (cw) Doppler (n= 50) or a lightweight (2.4 kg) portable duplex device (n= 102) in a prospective study of 76 high-risk patients. The screening protocols included either spectrum analysis and frequency shift measurement in both internal carotid arteries with cw-Doppler or determination of area and diameter ratios in transverse and longitudinal views of both carotid arteries in B-mode and with PDI, but without velocity measurement. Both protocols were evaluated against a complete routine duplex ultrasonography examination. RESULTS: According to the complete examination, stenoses were <50% in 73 of 102 (71.6%), 50-75% in 19 of 102 (18.6%), 75-95% in 7 of 102 (6.9%), and occluded in 3 of 102 (2.9%) arteries (PDI cohort), and <50% in 39 of 50 (78%), 50-75% in 8 of 50 (16%), 75-95% in 2 of 50 (4%), and occluded in 1 of 50 (2%) artery (cw-Doppler cohort). Mean screening time was 8.8 +/- 2.5 minute (PDI) and 9.4 +/- 2.6 minute (cw-Doppler). For stenoses >75%, A(z) values (area under the receiver operating characteristics curve) were 0.897 for area ratios, 0.843 for diameter ratios (PDI protocol) and 1.0 for the cw-Doppler protocol. CONCLUSIONS: The diagnostic performance of the cw-Doppler protocol was superior to the PDI protocol. Nevertheless, both protocols appear suitable as inexpensive screening strategies to identify subjects with >75% stenosis measured by carotid Doppler ultrasound. However, these preliminary data need further verification.

Aged↗

PubMed2003

Procalcitonin in pediatric emergency departments for the early diagnosis of invasive bacterial infections in febrile infants: results of a multicenter study and utility of a rapid qualitative test for this marker.

BACKGROUND: Procalcitonin (PCT) is a potentially useful marker in pediatric Emergency Departments (ED). The basic objectives of this study were to assess the diagnostic performance of PCT for distinguishing between viral and bacterial infections and for the early detection of invasive bacterial infections in febrile children between 1 and 36 months old comparing it with C-reactive protein (CRP) and to evaluate the utility of a qualitative rapid test for PCT in ED. METHODS: Prospective, observational and multicenter study that included 445 children who were treated for fever in pediatric ED. Quantitative and qualitative plasma values of PCT and CRP were correlated with the final diagnosis. To obtain the qualitative level of PCT the BRAHMS PCT-Q rapid test was used. RESULTS: Mean PCT and CRP values in viral infections were 0.26 ng/ml and 15.5 mg/l, respectively. The area under the curve obtained for PCT in distinguishing between viral and bacterial infections was 0.82 (sensitivity, 65.5%; specificity, 94.3%; optimum cutoff, 0.53 ng/ml), whereas for CRP it was 0.78 (sensitivity, 63.5%; specificity, 84.2%; optimum cutoff, 27.5 mg/l). PCT and CRP values in invasive infections (PCT, 24.3 ng/ml; CRP 96.5 mg/l) were significantly higher than those for noninvasive infections (PCT, 0.32 ng/ml; CRP, 23.4 mg/l). The area under the curve for PCT was 0.95 (sensitivity, 91.3%; specificity, 93.5%; optimum cutoff, 0.59 ng/ml), significantly higher (P < 0.001) than that obtained for CRP (0.81). The optimum cutoff value for CRP was >27.5 mg/l with sensitivity and specificity of 78 and 75%, respectively. In infants in whom the evolution of fever was <12 h (n = 104), the diagnostic performance of PCT was also greater than that of CRP (area under the curve, 0.93 for PCT and 0.69 for CRP; P < 0.001). A good correlation between the quantitative values for PCT and the PCT-Q test was obtained in 87% of cases (kappa index, 0.8). The sensitivity of the PCT-Q test (cutoff >0.5 ng/ml) for detecting invasive infections and differentiating them from noninvasive infections was 90.6%, with a specificity of 83.6%. CONCLUSIONS: PCT offers better specificity than CRP for differentiating between the viral and bacterial etiology of the fever with similar sensitivity. PCT offers better sensibility and specificity than CRP to differentiate between invasive and noninvasive infection. PCT is confirmed as an excellent marker in detecting invasive infections in ED and can even make early detection possible of invasive infections if the evolution of the fever is <12 h. The PCT-Q test has a good correlation with the quantitative values of the marker.

Bacteremia↗

PubMed2005

Comparison of US and unenhanced multi-detector row CT in patients suspected of having acute appendicitis.

PURPOSE: To prospectively compare the diagnostic performance of ultrasonography (US) and unenhanced multi-detector row computed tomography (CT) in patients suspected of having acute appendicitis by using surgery or clinical follow-up as the reference standard. MATERIALS AND METHODS: The institutional review board approved the research protocol. Written informed consent was obtained from all patients or, for those who were adolescents, from their parents. Ninety-four patients (59 female and 35 male patients) aged 16-81 years (mean, 38 years) who were suspected of having acute appendicitis underwent both US and unenhanced multi-detector row CT of the entire abdomen. The examinations were performed within 1-2 hours of each other. US and CT images were obtained and prospectively interpreted by a different radiologist from a group of abdominal radiologists or a group of residents and general radiologists. Radiologists proposed an overall diagnosis and an alternative diagnosis. Data from US and CT were compared, and the definite diagnosis was established with surgical findings (n = 40) or results of clinical follow-up (n = 54) as the reference standard. Comparisons were made for each group of radiologists and the patient's age, body mass index (BMI), and sex. Proportion comparisons were made by using the Pearson chi2 test or the Fisher exact test. Continuous variables were compared between groups with the Mann-Whitney U test. RESULTS: Thirty patients had definite appendicitis. The sensitivity, specificity, positive and negative predictive values, and accuracy were not significantly different between US and CT or between groups of radiologists (P values ranged from .389 to >.99), regardless of the patient's BMI (P values ranged from .073 to >.99). Misclassifications were compared with the definite alternative diagnosis and were not significantly different between US and CT or between groups of radiologists (P = .061-.592), regardless of patient age (P = .875) or sex (P = .151 and >.99 for male and female patients, respectively). The frequency of inconclusive examinations, however, was significantly higher with US than with CT, regardless of radiologist experience (P = .020 and <.001, respectively). CONCLUSION: Although the diagnostic performances of US and multi-detector row CT are comparable, more inconclusive images were obtained with US.

Acute Disease↗

PubMed1999

Myoglobin, creatine-kinase-MB and cardiac troponin-I 60-minute ratios predict infarct-related artery patency after thrombolysis for acute myocardial infarction: results from the Thrombolysis in Myocardial Infarction study (TIMI) 10B.

OBJECTIVES: We examined the diagnostic performance of serum myoglobin, creatine-kinase-MB (CK-MB) and cardiac troponin-I (cTnI) for predicting the infarct-related artery (IRA) patency in patients receiving TNK-tissue plasminogen activator (TNK-tPA) therapy for acute myocardial infarction (AMI) in the Thrombolysis in Myocardial Infarction (TIMI) 10B trial. BACKGROUND: A reliable noninvasive serum marker of IRA patency is desired to permit early identification of patients with a patent IRA after thrombolysis. METHODS: We measured myoglobin, CK-MB and cTnI concentrations in sera obtained just before thrombolysis (T0) and 60 min later (T60) in 442 patients given TNK-tPA and who underwent coronary angiography at 60 min. RESULTS: Angiography at 60 min showed a patent IRA (TIMI flow grade 2, 3) in 344 and occluded IRA (TIMI flow grade 0, 1) in 98 patients. The median serum T60 concentration, the ratio of the T60 and T0 serum concentration (60-min ratio) and the slope of increase over 60 min for each serum marker were significantly higher in patients with patent arteries compared with patients with occluded arteries. The area under the receiver-operating characteristic (ROC) curve for diagnosis of occlusion was 0.71, 0.70 and 0.71 for the 60-min ratio of myoglobin, cTnI and CKMB, respectively. The 60-min ratios of > or =4.0 for myoglobin, > or =3.3 for CK-MB and > or =2.0 for cTnI yielded a probability of patency of 90%, 88% and 87%, respectively. CONCLUSIONS: The diagnostic performance of serum myoglobin, CK-MB and cardiac troponin-I (cTnI) 60-min ratios was similar. The probability of a patent IRA was very high (90%) in patients with 60-min myoglobin ratio > or =4.0, and early invasive interventions to establish IRA patency may not be necessary in this group. Serum marker determinations at baseline and 60-min after thrombolysis may permit rapid triage of patients receiving thrombolytic therapy by ruling out IRA occlusion.

Aged↗

PubMed2006

MRI of meniscal lesions: soft-copy (PACS) and hard-copy evaluation versus reviewer experience.

OBJECTIVE: The purpose of our study was to compare diagnostic performance, reviewer confidence, and time requirements in the MRI diagnosis of meniscal tears for three types of reviewers and two types of image documentations (PACS vs hard copies). MATERIALS AND METHODS: An experienced musculoskeletal radiologist (reviewer 1), a fellow in musculoskeletal radiology (reviewer 2), and a junior staff member in orthopedic surgery (reviewer 3) evaluated MR images displayed on PACS monitors and hard copies independently and in a blinded fashion with regard to the presence or absence of meniscal tears. Seventy-one patients (mean age, 45.4 years; range, 16-80 years) were consecutively included if they had undergone both MRI of the knee and arthroscopy within 4 months. Arthroscopy was the standard of reference. Evaluation time and the reviewer's confidence in his or her diagnosis (Visual Analogue Scale, possible values of 0-100) were determined. RESULTS: Accuracies, sensitivities, and specificities in diagnosing meniscal tears were 80-87%, 63-85%, and 87-93% for soft copies and 82-85%, 64-76%, and 87-94.0%, respectively, for hard copies. Intrareviewer differences between PACS and hard copies were not significant for any of the three reviewers (McNemar tests). Reviewer 3 was less sensitive but more specific in the diagnosis of meniscal tears than reviewers 1 and 2. This difference was significant for both the PACS and hard copies. The reviewers' confidence in their diagnoses and evaluation times were not significantly different for PACS and hard copies (analysis of variance with Bonferroni post hoc analysis). CONCLUSION: Differences in the diagnostic performance of suspected meniscal tears depend on reviewer experience rather than on the type of documentation.

Adolescent↗

PubMed2006

Added value of SPECT/CT in patients suspected of having bone infection: preliminary results.

AIM: We evaluated the contribution of SPECT/CT as an adjunct to combined three-phase bone scintigraphy (planar and SPECT) for diagnosing and localizing bone infection. Subsequently, the diagnostic performance of SPECT/CT was compared to visual fusion of SPECT with data of additional CT, X-ray, or MRI studies (SPECT + CT/X-ray/MRI). MATERIALS AND METHODS: Thirty-one patients suspected of bone infection, presenting pathological findings on triple-phase bone scintigraphy, underwent additional SPECT/CT. The SPECT/CT-technology combines the acquisition of SPECT and CT data with the same imaging device enabling perfect overlay of anatomical and functional images. (99m)Tc-DPD was used as radiopharmaceutical in all patients. For data analysis findings of bone scintigraphy (planar scans as well as SPECT) were categorized as positive, negative, or equivocal for the presence of osteomyelitis. In a second step, they were compared with SPECT/CT and SPECT + CT/X-ray/MRI with respect to localization and classification of lesions. Validation was achieved by surgery, biopsy, or by clinical follow up over at least 9 months including microbiological and radiological findings. RESULTS: Three-phase bone scan (incl. SPECT) correctly classified 7 lesions as positive and 11 lesions as negative for osteomyelitis. Six scans were interpreted false positive, two false negative, and five as equivocal. Rating the latter as positive for osteomyelitis, sensitivity of bone scan was (78%), specificity (50%). SPECT/CT was true positive in 7 patients, and true negative in 19. There were two false positive and two false negative findings, one scan was equivocal (sensitivity 78%, specificity 86%). Definition of anatomical localization of inflammatory foci was much easier by SPECT/CT due to better depiction of underlying anatomical details. SPECT + CT/X-ray/MRI yielded the highest sensitivity (100% compared to 78% of SPECT/CT), if equivocal findings (5/31 compared to 1/31 for SPECT/CT) are rated as true positive for osteomyelitis. Among radiological techniques, MRI (2 x FP) and CT (2 x FN) proved equal and expectedly superior to X-ray in delivering the correct diagnosis. CONCLUSION: SPECT/CT improves the diagnostic performance of three-phase bone scan for osteomyelitis by avoiding false positive or equivocal results. An additional benefit over visual fusion of SPECT with X-ray, CT, or MRI studies could not be confirmed in our study.

Adult↗

PubMed1999

Reevaluation of the ABCD rule for epiluminescence microscopy.

BACKGROUND: Epiluminescence microscopy (ELM) provides for increased accuracy in the clinical diagnosis of pigmented skin lesions (PSL). It is based on pattern analysis of ELM criteria, which requires experience. The recently introduced application of the ABCD score to ELM facilitates this by permitting lesion evaluation on the basis of predefined clinical criteria. OBJECTIVE: The present study was performed to evaluate the diagnostic performance of the ABCD rule for ELM in pigmented skin lesions testing dermatologists with varying skills from novice to expert. METHODS: Two hundred fifty electronic images of randomly selected, histologically proven PSL including 41 early melanomas (16.4%) were presented to the raters, and each image was scored according to the rules of the ABCD score and rated without the guidance of a scoring system on a scale from 1 = definitely benign to 5 = definitely melanoma. RESULTS: Our data show that the application of the ABCD rule significantly enhances diagnostic ability in less experienced dermatologists compared with rating without the guidance of a scoring system. In contrast, the diagnostic accuracy of dermatologists who are moderately to greatly experienced is not improved by use of the ABCD rule. CONCLUSION: Our experiments indicate that the application of the ABCD rule to ELM introduced by Stolz et al represents a useful enhancement for diagnosis of pigmented skin lesions in less experienced users. However, the method does fail to detect melanomas with 100% accuracy. Therefore further effort has to be made to make the diagnosis of melanoma easier and more accurate.

Clinical Competence↗