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Quantitative contrast-enhanced harmonic EUS in differential diagnosis of focal pancreatic masses (with videos).
Săftoiu, A, Vilmann, P, Dietrich, CF, Iglesias-Garcia, J, Hocke, M, Seicean, A, Ignee, A, Hassan, H, Streba, CT, Ioncică, AM, et al
Gastrointestinal endoscopy. 2015;(1):59-69
Abstract
BACKGROUND The role of EUS with contrast agents can be expanded through the use of time-intensity curve (TIC) analysis and computer-aided interpretation. OBJECTIVE To validate the use of parameters derived from TIC analysis in an artificial neural network (ANN) classification model designed to diagnose pancreatic carcinoma (PC) and chronic pancreatitis (CP). SETTING Prospective, multicenter, observational trial-endoscopy units from Romania, Denmark, Germany, and Spain. PATIENTS A total of 167 consecutive patients with PC or CP. INTERVENTIONS Contrast-enhanced harmonic EUS (CEH-EUS) and EUS-guided FNA (EUS-FNA), TIC analysis, and ANN processing. MAIN OUTCOME MEASUREMENTS Sensitivity, specificity, positive and negative predictive values (PPV, NPV) for EUS-FNA, CEH-EUS, and the ANN. RESULTS After excluding all of the recordings that did not meet the technical and procedural criteria, 112 cases of PC and 55 cases of CP were included. EUS-FNA was performed in 129 patients, and the diagnosis was confirmed by surgery (n = 15) or follow-up (n = 23) in the remaining cases. Its sensitivity and specificity were 84.82% and 100%, respectively, whereas the PPV and NPV were 100% and 76.63%, respectively. The sensitivity of real-time quantitative assessment of CEH-EUS was 87.5%, specificity 92.72%, PPV 96.07%, and NPV 78.46%. Peak enhancement, wash-in area under the curve, wash-in rate, and the wash-in perfusion index were significantly different between the groups. No significant differences were found between rise time, mean transit time, and time to peak. For the ANN, sensitivity was 94.64%, specificity 94.44%, PPV 97.24%, and NPV 89.47%. LIMITATIONS Only PC and CP lesions were included. CONCLUSION Parameters obtained through TIC analysis can differentiate between PC and CP cases and can be used in an automated computer-aided diagnostic system with good diagnostic results. ( CLINICAL TRIAL REGISTRATION NUMBER NCT01315548.).
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Comparison of HR MAS MR spectroscopic profiles of breast cancer tissue with clinical parameters.
Sitter, B, Lundgren, S, Bathen, TF, Halgunset, J, Fjosne, HE, Gribbestad, IS
NMR in biomedicine. 2006;(1):30-40
Abstract
Breast cancer is the most frequent form of cancer in women and improved diagnostic methods are desirable. Malignant cells have altered metabolism and metabolic mapping might become a tool in cancer diagnostics. High-resolution magic angle spinning (HR MAS) MR spectroscopy of tissue biopsies provides detailed information on metabolic composition. The 600 MHz 1H HR MAS spectra were acquired of breast cancer tissue from 85 patients and adjacent non-involved tissue from 18 of these patients. Tissue specimens were investigated by microscopy after MR analysis. The resulting spectra were examined by three different approaches. Relative intensities of glycerophosphocholine (GPC), phosphocholine (PC) and choline were compared for cancerous and non-involved specimens. Eight metabolites, choline, creatine, beta-glucose, GPC, glycine, myo-inositol, PC and taurine, were quantified from the recorded spectra and compared with tumor histological type and size, patient's lymph node status and tissue composition of sample. The spectra were also compared with tumor histological type and size, lymph node status and tissue composition of samples using principal component analysis (PCA). Tumor samples could be distinguished from non-involved samples (82% sensitivity, 100% specificity) based on relative intensities of signals from GPC, PC and choline in 1H HR MAS spectra. Tissue concentrations of metabolites showed few differences between groups of samples, which can be caused by limitations in the quantification procedure. Choline and glycine concentrations were found to be significantly higher in tumors larger than 2 cm compared with smaller tumors. PCA of MAS spectra from patients with invasive ductal carcinomas indicated a possible prediction of spread to axillary lymph nodes. Metabolite estimates and PCA of MAS spectra were influenced by the percentage of tumor cells in the investigated specimens.
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A comparison of prediction equations for estimating glomerular filtration rate in adult patients with chronic kidney disease stages 4-5. Effect of nutritional status and age.
Fontseré, N, Bonal, J, Navarro, M, Riba, J, Fraile, M, Torres, F, Romero, R
Nephron. Clinical practice. 2006;(4):c160-8
Abstract
BACKGROUND The accuracy of prediction equations has not been validated in adult patients with chronic kidney disease (CKD) stages 4-5 in extreme situations of nutritional status and age. OBJECTIVE AND METHODS The significance of nutritional status, calculated with the creatinine production (CP) formula, and age (< or =64 years and >64 years) in the application of different prediction equations--modification of diet in renal disease (MDRD), simplified MDRD (sMDRD), Cockcroft-Gault (CG)--and the mean of urea and creatinine clearance (Cr-Ur) compared with the isotopic glomerular filtration rate (GFR) estimation calculated by 51Cr-EDTA was studied in 87 Caucasian adults with CKD stages 4-5 (GFR: 30-8 ml/min/1.73 m2). The Bland-Altman method and Lin's concordance coefficient (Rc) were used to study accuracy (bias) and precision. RESULTS The GFR calculated with 51Cr-EDTA in the study group was 22.2 +/- 6.9 ml/min/1.73 m2 (range: 8-30). CG and sMDRD were the best prediction equations with bias of -1.1 and -3.8 ml/min/1.73 m2 and Rc of 0.52-0.50. In this situation, the mean Cr-Ur proved the most inaccurate equation compared with the isotopic technique with bias of -5.4 ml/min/1.73 m2 and Rc of 0.32. In the analysis of patients with higher CP (> 0.90; n = 44), CG and sMDRD obtained the best bias of 1.2 and -2.7 ml/min/1.73 m2 and Rc of 0.54-0.53. In patients aged < or =64 (n = 44), these equations obtained a bias of 1.1 and -3.6 ml/min/1.73 m2 and Rc 0.50-0.49. Both in lower CP (< or =0.90; n = 43) and older age (>64 years; n = 43), all the equations underestimated the value obtained with isotopic GFR. In these situations, the results obtained with CG had a bias of -2.2 and -3.6 ml/min/1.73 m2 (Rc 0.29-0.56) and with sMDRD -4.0 and -4.1 ml/min/1.73 m2 (Rc 0.39-0.51). In these circumstances, Cr-Ur was the most inaccurate equation, obtaining a bias of -10.1 and -13.2 ml/min/1.73 m2 (Rc 0.14-0.16). CONCLUSIONS In the group with higher CP and age < or =64 years, results of the presented data yielded no evidence for superiority of the MDRD equation over CG formula in patients with advanced renal failure. On the basis of our results, we do not recommend the use of the Cr-Ur adjusted to 1.73 m(2) of body surface area, which was the most imprecise equation. Application of all the equations proved inaccurate in lower CP patients with or without advanced age, implying the premature start of substitution renal treatment. In these circumstances, ambulatory GFR determination by isotopic techniques would be indicated.
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1H NMR spectroscopic method for diagnosis of malabsorption syndrome: a pilot study.
Bala, L, Nagana Gowda, GA, Ghoshal, UC, Misra, A, Bhandari, M, Khetrapal, CL
NMR in biomedicine. 2004;(2):69-75
Abstract
Despite its well-documented limitations, colorimetry has been commonly used for the d-xylose test in the diagnosis of malabsorption syndrome (MAS). With a possibility of overcoming its limitations, the use of (1)H NMR spectroscopy for D-xylose test is explored herein. Urine samples from 35 adults with suspected MAS were obtained before and after oral ingestion of D-xylose. The diagnosis of MAS was based on fecal fat (72 h excretion using Van de Kamer's technique, normal < 7 g/24 h and/or Sudan III stain of spot stool specimen, normalor=1 g/5 g/5 h). In vitro experiments on the standard specimens of D-xylose were also performed independently using both methods. Colorimetry showed a lower value for the quantity of D-xylose excreted in urine than NMR [median 0.73 (0.17-1.89 g) vs 1.37 (0.17-3.23 g), respectively; p<0.0001, Wilcoxon's signed ranks test]. Colorimetry and NMR correctly diagnosed 11/12 and 10/12 (p=N.S.) patients with MAS and 14/23 and 20/23 (p<0.05) without MAS, respectively. Sensitivity and specificity of colorimetry and NMR were 91.6 and 60.7% vs 83.3 and 86.9%, respectively. In in vitro experiments, the values obtained for standard xylose using NMR showed a maximum error of 7%, whereas the colorimetric method showed 20%. The NMR method is simple and may be more accurate for the D-xylose absorption test. Colorimetry was found to be inferior as compared with NMR due to its low specificity.
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Tele-screening for diabetic retinopathy with the retinal thickness analyzer.
Neubauer, AS, Welge-Lüssen, UC, Thiel, MJ, Alge, C, Priglinger, SG, Hirneiss, C, Ulbig, MW, Kampik, A
Diabetes care. 2003;(10):2890-7
Abstract
OBJECTIVE To compare the effectiveness of tele-screening using a novel enhanced retinal thickness analyzer (RTA) with onsite routine ophthalmologic examination for diabetic retinopathy. RESEARCH DESIGN AND METHODS A consecutive series of 31 eyes from diabetic patients were included. All underwent ophthalmologic examination, including stereoscopic dilated funduscopy and scanning with the RTA. The RTA reports consisted of a wide-angle, red-free fundus photograph and a macular-region retinal thickness map. Reports were graded by three independent graders in a masked manner. The diagnoses of proliferative retinopathy, macular edema, and treatment decisions made by the RTA graders and the clinical examiner were compared. RESULTS On clinical examination 5 of 31 eyes were diagnosed with proliferative diabetic retinopathy (PDR). All five were referred for treatment by two graders and four eyes by one grader. All eyes with PDR and 12 of the 26 eyes with nonproliferative diabetic retinopathy showed severe macular edema. Seven of the 12 eyes with macular edema were clinically eligible for focal laser treatment, and all of them were detected by all RTA graders. Macular thickening was detected in eight eyes by RTA where no treatment was necessary, as judged by clinical examination. Thus, sensitivity was 93% (mean) for detecting PDR and 100% for detecting macular edema, with a specificity of 58-96% depending on the grader. The RTA did not allow valid assessment due to poor image quality in only one case. CONCLUSIONS Screening for diabetic retinopathy with a combination of wide-angle fundus photography and macular thickness mapping by an objective method, such as optical coherence tomography or the RTA, offers the prerequisites for establishing a successful tele-screening program.