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Results for “Repeatability and Reproducibility”

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PubMed1996

The topographic representation of esophageal motor function on the human cerebral cortex.

BACKGROUND & AIMS: Corticofugal pathways to the human esophagus have been recently identified in humans using transcranial magnetic stimulation. The aim of this study was to determine the topographic representation of the esophagus on the cerebral cortex. METHODS: Focal magnetic stimulation of 1-cm areas was performed over both hemispheres in 10 healthy subjects. Esophageal electromyographic responses were recorded 2 cm below the upper esophageal sphincter. The studies were repeated to determine reproducibility in 3 subjects; in 2 subjects, esophageal topography was compared with thenar muscle topography. RESULTS: In all subjects, esophageal electromyographic responses were evoked by stimulation of either the right or left hemisphere. Largest amplitude responses were obtained anterior to those of the thenar muscles, indicating that the esophagus may be represented on either the anterior aspect of the motor cortex or on the premotor cortex. In all subjects, the area of response was asymmetric, being more extensive on the right hemisphere than on the left hemisphere in 8 subjects. In 2 subjects, the area of response on the left hemisphere was more extensive than on the right. Repeat studies showed that this asymmetry was consistent. CONCLUSIONS: Esophageal motor function shows bilateral cortical representation with consistent interhemispheric asymmetry.

Adult↗

PubMed1985

Epidemiology of polyps in the rectum and sigmoid colon. Endoscopic evaluation of size and localization of polyps.

The reproducibility of polyp localization and size measurements was tested to evaluate the reliability of observations during follow-up examinations of sigmoidoscopically diagnosed polyps. Our findings suggest that 25% of polyps less than 5 mm in diameter but only 5% of those larger than 5 mm are likely to be missed by a single endoscopic examination. Localization measurements made during insertion and withdrawal of the endoscope on different days of examination diverged proximal to 30 cm from the anal ring during repeat colonoscopy. Otherwise, reproducibility was good, demonstrating that sigmoidoscopy may be a fairly accurate procedure for evaluation of site and size of polyps during follow-up studies.

Colonic Polyps↗

PubMed2000

Identification and quantification of flavonoids in human urine samples by column-switching liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry.

A rapid and sensitive high-performance liquid chromatographic mass spectrometric (HPLC-MS) method is described for the determination and quantification of 12 dietary flavonoid glycosides and aglycons in human urine samples. Chromatographic separation of the analytes of interest was achieved by column-switching, using the first column (a Zorbax 300SB C-3 column) for sample cleanup and eluting the heart-cut flavonoid fraction onto the second column (a Zorbax SB C-18 column) for separation and detection by ultraviolet and atmospheric pressure chemical ionization MS using single ion monitoring in negative mode. The fragmentor voltage was optimized with regard to maximum abundance of the molecular ion and qualifier ions of the analytes. Calibration graphs were prepared for urine, and good linearity was achieved over a dynamic range of 2.5-1000 ng/mL. The inter- and intraassay coefficients of variation for the analysis of the 12 different flavonoids in quality control urine samples were 12.3% on average (range 11.0-13.7%, n = 24, reproducibility) and the repeatability of the assay were 5.0% (mean, range 0.1-14.8%, n = 12). A subset of 10 urine samples from a human dietary intervention study with high and low flavonoid content was analyzed, and the results are reported.

Atmospheric Pressure↗

PubMed2001

Coronary flow reserve: measurement with transthoracic Doppler echocardiography is reproducible and comparable with positron emission tomography.

Detection of early vascular changes indicated by lowered coronary flow reserve (CFR) would allow early treatment and prevention of atherosclerosis. The purpose of this study was to test whether it is possible to reproducibly measure CFR with transthoracic Doppler echocardiography (TTE) in healthy volunteers. We measured CFR using dipyridamole infusion in ten healthy male volunteers with two methods: TTE and positron emission tomography (PET) with oxygen-15-labelled water (group A). However, CFR was assessed twice with TTE in eight healthy male volunteers (group B) to study the reproducibility of this method. We compared CFRs obtained using TTE flow measurements in the left anterior descending coronary artery (LAD) and PET flow measurements in the corresponding myocardial area. Coronary flow in LAD could be measured in all subjects using TTE. By TTE, an average CFR based on peak diastolic flow velocity (PDV) was 2.72 +/- 1.16, mean diastolic flow velocity (MDV) 2.56 +/- 1.06 and velocity time integral (VTI) 1.87 +/- 0.49. The results were reproducible in two repeated TTE studies (coefficient of variation in MDV 6.1 +/- 4.3%, n=8). By PET, CFR was 2.52 +/- 0.84. CFR assessed by TTE correlated closely with that measured by PET (MDV r=0.942, P<0.001; PDV r=0.912, P<0.002 and VTI r=0.888, P<0.006) and intraclass correlation was 0.929 (MDV) and tolerance limits for differences of CFRs was -0.78 to 0.72. We show that CFR measured by TTE has an excellent correlation with CFR measured by PET. We also found that TTE measurements of CFR were highly reproducible.

Adolescent↗

PubMed2006

Double gradient ion chromatography using short monolithic columns modified with a long chained zwitterionic carboxybetaine surfactant.

The rapid separation of inorganic anions on short monolithic columns permanently coated with a long chained zwitterionic carboxybetaine-type surfactant is shown. The surfactant, N-dodecyl-N,N-(dimethylammonio)undecanoate (DDMAU), was used to coat 2.5, 5.0 and 10 cm long reversed-phase silica monoliths, resulting in a permanent zwitterionic exchange surface when used with aqueous based eluents. The unique structure of the surfactant results in a charge double layer structure on the surface of the stationary phase, with strong internal anionic and weak external cationic exchange groups. The dissociation of the weak external carboxylic acid group acts to shield the inner anionic exchange site, resulting in substantial effective capacity changes with eluent pH. Utilising this effect with the application of an eluent pH gradient, simultaneously combined with eluent flow-rate gradients, very rapid simultaneous separations of both weakly retained anions and strongly retained polarisable anions was possible, with up to 10-fold decreases in overall run times. Coating stability and retention times under isocratic and isofluentic eluent conditions were shown to be reproducible over >450 repeat injections, with peak efficiency values averaging 29,000 N/m for the 2.5 cm column and 42,000 N/m for the 10 cm monolithic column, again under isocratic elution conditions.

Anions↗

PubMed2003

Repeatability over time of posture, radiograph positioning, and radiograph line drawing: an analysis of six control groups.

BACKGROUND: There is debate concerning the repeatability of posture over time, radiograph positioning repeatability, and radiograph line drawing reliability. These ideas seem to negate the use of before-and-after spinal radiographic imaging to detect and correct vertebral subluxations. OBJECTIVE: To review the results of control groups in 6 clinical control trials with before-and-after radiographic measurements taken days, weeks, months, or years apart to accept or reject the hypothesis that radiographic analysis procedures are not repeatable, reliable, or reproducible. DATA SOURCES: Six published control groups from original data. Other data were obtained from searches on MEDLINE, CHIROLARS, MANTIS, and CINAHL on radiographic reliability, posture, and positioning. RESULTS: Comparison of initial and follow-up radiographic data for 6 control groups indicate that measured angles and distances between initial and follow-up radiograph measurements on lateral and anterior to posterior radiographs are not significantly different when utilizing Chiropractic Biophysics radiographic procedures. In 48 out of 50 measurements, the differences between initial and follow-up radiographs are less than 1.5 degrees and 2 mm. These measurements indicate that posture is repeatable, radiographic positioning is repeatable, and radiographic line drawing analysis for spinal displacement is highly reliable. The scientific literature on these topics also indicates the repeatability of posture, radiographic positioning, and radiographic line drawing. CONCLUSIONS: Posture, radiographic positioning, and radiographic line drawing are all very reliable/repeatable. When Chiropractic Biophysics standardized procedures are used, any pre-to-post alignment changes in treatment groups are a result of the treatment procedures applied. These results contradict common claims made by several researchers and clinicians in the indexed literature. Chiropractic radiologic education and publications should reflect the recent literature, provide more support for posture analysis, radiographic positioning, radiographic line drawing analyses, and applications of posture and radiographic procedures for measuring spinal displacement on plain radiographs.

Biomechanical Phenomena↗

PubMed2005

Radiographic measurement of anterior talar translation in the ankle: determination of the most reliable method.

BACKGROUND: Although most would agree that stress radiography is an important research tool to evaluate the integrity of the ankle ligaments in studies of chronic ankle instability, there is little agreement with regard to the best technique to make these measurements. The primary objective of this study was to establish the most reliable method for measuring anterior displacement of the talus relative to the tibia using stress radiographs of the ankle. This information is necessary to standardize radiographic evaluation of injured ankles and for biomechanical studies of the ankle joint, but has never been investigated. METHODS: This study examined the reliability of four available methods by measuring the intra-observer repeatability and inter-observer reproducibility of three different investigators. Lateral radiographs were obtained while the ankle was supported in the Telos device with the joint unloaded, and then with a 150 N anterior directed load applied to the calcaneus. At two separate time intervals, the radiographs were read by three different observers using four measurement techniques. For each technique, the measurement of the unloaded ankle was subtracted from the loaded ankle to obtain anterior talar translation. FINDINGS: The method that measured the shortest distance between the posterior lip of the distal tibia and the talar dome (designated Method I in the current series) was significantly more reproducible between readers and within readers across repeated measurements than the other methods tested. INTERPRETATION: Based on the findings from this study, it can be concluded that measurement of the distance between the posterior lip of the distal tibia and the talar dome is the method of choice to characterize the position of the talus relative to the tibia in stress radiography. In order to standardize the radiographic evaluation of ankle injuries, this method should be the one employed to measure anterior talar translation.

Ankle Injuries↗

PubMed2001

Monitoring signal transduction in cancer: cDNA microarray for semiquantitative analysis.

This study targeted the development of a novel microarray tool to allow rapid determination of the expression levels of 58 different tyrosine kinase (tk) genes in small tumor samples. The goals were to define a reference probe for multi-sample comparison and to investigate the variability and reproducibility of the image acquisition and RT-PCR procedures. The small number of tk genes on our arrays enabled us to define a reference probe by artificially mixing all genes on the arrays. Such a probe provided contrast reference for comparative hybridization of control and sample DNA and enabled cross-comparison of more than two samples against one another. Comparison of signals generated from multiple scanning eliminated the concern of photo bleaching and scanner intrinsic noise. Tests performed with breast, thyroid, and prostate cancer samples yielded distinctive patterns and suggest the feasibility of our approach. Repeated experiments indicated reproducibility of such arrays. Up- or downregulated genes identified by this rapid screening are now being investigated with techniques such as in situ hybridization.

Breast Neoplasms↗

PubMed1991

Preliminary evaluation of sensititre system for identifying gram-negative bacilli.

The automated microdilution Sensititre System (Sensititre, LtD.) was evaluated for the identification of 120 clinically isolated fermenter and non-fermenter Gram negative bacilli and of 12 ATCC reference strains (American Type Culture Collection). Daily and overnight (5 and 18 hours) identifications were performed according to the manufacturer. In both cases, the results were compared with those obtained with the overnight API 20E (API System, La Balme les Grottes, Montalieu Vercieu) used as reference method. Concordance between the results obtained after 5 hrs of incubation and those obtained with API 20E was found in 65% of cases (acceptable identification criteria with probability over 80%). When results were determined after 18 hrs of incubation (identification criteria with probably over 80%) concordance was found in 82.5%. Reproducibility obtained by repeated (10 times) identification with four different strains was 100% both at 5 hrs and 18 hrs. Identification accuracy of the 12 ATCC strains was 8/12 (66.6%) after 5 hrs and 12/12 (100%) after 18 hrs.

Evaluation Studies as Topic↗

PubMed2003

Simultaneous determination of hydroxycinnamates and catechins in human urine samples by column switching liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry.

A quantitative liquid chromatography mass spectrometry (LC-MS) methodology with online sample clean up by column switching is described for the simultaneous determination of the hydroxycinnamates, caffeic acid and chlorogenic acid, and of the catechins, epicatechin and catechin in human urine samples. Enzymatically treated urine samples were directly injected onto the LC-MS system, where sample clean up was performed by a reversed-phase Zorbax 300SB C(3) column and selective elution of the target compounds onto a Zorbax SB C(18) column resulted in final separation prior to detection by atmospheric pressure chemical ionization (APCI) MS using single ion monitoring (SIM) in negative mode. Linear calibration graphs were achieved in the dynamic range of 10-1000 ng/ml urine. The inter- and intraassay coefficients of variation (C.V.%) for the analysis of the four compounds in quality control urine samples were between 7.8 and 10.9, n=17 (reproducibility), and the repeatability of the assay was between 2.5 and 5.0% (n=12). Analyses of urine samples from a human dietary intervention study with intake of 600 g of fruits and vegetables were demonstrated. To our knowledge, this is the first method described that allows simultaneous determination of both hydroxycinnamates and catechins in biological samples.

Atmospheric Pressure↗

PubMed2005

2-[11C]thymidine positron emission tomography reproducibility in humans.

PURPOSE: To evaluate the reproducibility of 2-[11C]thymidine positron emission tomography (PET) scanning in patients with advanced intra-abdominal malignancies. PATIENTS AND METHODS: The reproducibility of 2-[11C]thymidine PET was studied by comparing interpatient and intrapatient variability (coefficient of variability, COV) of both blood and tissue data. Arterial plasma metabolite levels were measured using on-line sampling and high-pressure liquid chromatography. 2-[11C]Thymidine retention in tissue was measured as the standardized uptake value at the end of the scan (SUV(end)), the area under the time-activity curve (AUC(0-1 hour)), and the fractional retention of thymidine (FRT). A group of seven patients were scanned 1 week apart with no intervening anticancer therapy. RESULTS: There was interpatient variability in the levels of 2-[11C]thymidine and its main metabolite, 11CO2, in plasma. Variability in 2-[11C]thymidine PET data was greater between (COV: SUV(end) = 38%, AUC(0-1 hour) = 32%, FRT = 47%) than within (COV: SUV(end) = 8%, AUC(0-1 hour) = 2%, FRT = 9%) patients. There was a borderline significant difference between the paired tumor data for SUV(end) (P = 0.041), but not for AUC(0-1 hour) (P = 0.81) or FRT (P = 0.90). There was a good correlation between paired data for SUV(end) (r = 0.98), AUC(0-1 hour) (r = 0.99), and FRT (r = 0.95). CONCLUSIONS: This is the first report showing that 2-[11C]thymidine PET scanning is reproducible in humans. Repeat scanning of tumor proliferation using 2-[11C]thymidine PET is feasible to perform in human intra-abdominal malignancies and should aid the future rapid assessment of antiproliferative tumor agents.

Abdominal Neoplasms↗

PubMed1998

Evaluation of the Vitek system to accurately test the susceptibility of Pseudomonas aeruginosa clinical isolates against cefepime.

A total of 300 recent blood stream and pneumonia isolates of Pseudomonas aeruginosa from 32 different medical centers in the United States were used to assess the accuracy of the Vitek System (GNS-107 card) for cefepime, a new "fourth-generation" cephalosporin. The Vitek System test result was compared to the consensus of the three other methods (reference broth microdilution, disk diffusion, Etest (AB BIODISK, Solna, Sweden)); and 271 of 300 consensus category of susceptibility sets were unanimous. The Vitek System produced a 25.3% error rate (5.3% false resistance, 20.0% minor errors). A consistent trend toward higher MIC results with the Vitek System was observed that produced a 15.3 to 21.3% lower susceptible rate compared with the other susceptibility test methods. The consensus cefepime resistance rate was only 4.3% compared to 14.0% for the Vitek GNS-107 card. The error was reproducible on triplicate repeat testing. These results indicate an unacceptable rate of false resistance being produced by the Vitek System when testing cefepime against P. aeruginosa strains. Alternative methods are suggested for this broad-spectrum antipseudomonal cephalosporin.

Bacteremia↗

PubMed2004

Increases in the density of parvalbumin-immunoreactive neurons in anterior cingulate cortex of amphetamine-withdrawn rats: evidence for corticotropin-releasing factor in sustained elevation.

We previously reported synchronization of pyramidal neurons within prefrontal cortex of rats repeatedly exposed to amphetamine (AMPH). To test the hypothesis that cortical synchronization may be related to changes in local GABA signaling, we used antibodies specific for parvalbumin (PV), calbindin D28k (CB) and calretinin (CR) as selective labels for three distinct GABA interneuron classes in the anterior cingulate cortex (ACC) of similarly treated rats. We observed a selective increase in the density of PV-immunoreactive (ir), but not CB-ir or CR-ir, neurons in the ACC of AMPH-treated rats at both 1 day and 7 day withdrawal. Increased density of PV-ir GABA interneurons in the ACC at 1 day withdrawal was reproduced in rats repeatedly injected with apomorphine or with SKF-38393. Thus, the critical role of DA receptors during AMPH exposure is evident. However, DA receptor activation did not appear to account for the PV up-regulation in AMPH-treated rats at 7 day withdrawal. Significantly higher numbers of pericellular basket-like puncta immunoreactive for corticotropin-releasing factor (CRF) were observed in the ACC of AMPH rats at 7 day withdrawal. Combined dual immunofluorescence and confocal microscopy further revealed that CRF-ir puncta made possible pericellular contacts on PV-ir (not CB-, CR- or glutamate-ir) cell bodies. A potential cellular mechanism seems to emerge that CRF-ir terminals, that may be underdetected under normal conditions due to low activity levels, may be functionally activated during psychostimulant withdrawal, thereby altering local GABAergic signaling.

Amphetamine↗

PubMed2001

Validation of ISO method 11290 part 2. Enumeration of Listeria monocytogenes in foods.

The European and International Standard method for the enumeration of Listeria monocytogenes, described in EN ISO 11290 Part 2: 1998 [EN ISO 11290-2 Microbiology of Food and Animal Feedingstuffs-Horizontal Method for the Detection and Enumeration of L. monocytogenes: Part 2. Enumeration; International Organisation for Standardisation, Geneva.] was validated by order of the European Commission (Standards, Measurement and Testing Fourth Framework Programme Project SMT4-CT96-2098). The objective was to determine the precision of the method in terms of repeatability (r) and reproducibility (R) using three different food types inoculated with various levels of L. monocytogenes and a typical background flora. The results are intended for publication in the associated standards. Cheese, meat, dried egg powder and reference materials were examined by 21 laboratories in 16 countries in Europe. Each participant received eight test materials per food type: blind duplicates at four inoculum levels (0, 10(2), 10(3), 10(4) cfu/g). In addition, two reference materials containing L. monocytogenes were included in the study. All test materials were subjected to stringent homogeneity and stability testing before being used in the collaborative trial. Participants were required to use only PALCAM agar for enumeration of L. monocytogenes, as prescribed by the reference method. Statistical analyses has been performed using a newly introduced approach for food microbiology (draft standard prEN ISO 16140 [prEN ISO 16140 Microbiology of Food and Animal Feedingstuffs-Protocol for the Validation of Alternative Methods, International Organisation for Standardisation, Geneva.], the precision data being calculated using robust estimates. Overall values for repeatability (r) of EN ISO 11290-2 when used with food test materials were r = log10 0.58 (expressed as an absolute difference between log10-transformed test results) or r = 3.8 (expressed as an absolute ratio between test results on the normal scale). For the reference materials (capsules containing approximately 5000 cfu), r = log10 0.34 (expressed as an absolute difference between log10-transformed test results) or r = 2.2 (expressed as an absolute ratio between test results on the normal scale). Overall values for reproducibility (R) of EN ISO 11290-2 when used with food test materials were R = log10 0.81 (expressed as a difference between log10-transformed test results) or R = 6.5 (expressed as an absolute ratio between test results on the normal scale). For the reference materials, R = log10 0.51 (expressed as a difference between log10-transformed test results) or R = 3.2 (expressed as an absolute ratio between test results on the normal scale). Further studies have been initiated by ISO TC34/SC9 to try to enhance the isolation of L. monocytogenes from foods and improve the confirmation procedures.

Animals↗

PubMed1990

[Fundamental evaluation of bone densitometry using dual energy X-ray absorptiometry (DEXA)].

A newly developed instrument based on dual energy X-ray absorptiometry (DEXA), Hologic QDR-1000, was evaluated fundamentally and clinically. Image quality was quite satisfactory though radiation exposure was minimal, 780.2 nC/kg (3.024 mR) for lumbar measurement. Reproducibility of the repeated measurement of a phantom was fairly good; 0.343 CV% in a same day and 0.520 CV% in a long period. Accuracy determined by measurement of potassium phosphate solution was also satisfactory. Bone mineral densities measured by this instrument were fairly correlated with those measured by single energy quantitative CT; coefficient was 0.740 for 17 patients. Mix-DP plates of more than 10 cm thick overestimated the bone mineral densities of a phantom. Bone mineral densities of Japanese normal volunteers were in the normal range (mean +/- 2SD) of the Americans though mostly lower than the mean. In patients with spondylosis deformans or prominent aortic calcification, bone mineral densities might be overestimated. Lateral view was obtainable though its reproducibility was not good. Positioning especially for measuring femoral neck was quite critical for reproducible measurement. In conclusion, this new instrument is quite accurate and satisfactory for clinical application to measuring bone mineral densities.

Absorptiometry, Photon↗

PubMed1984

Reproducibility and accuracy of left ventricular ejection fraction and wall motion determinations using gold-195m: a new ultrashort-lived radionuclide for cardiac studies.

Gold-195m has a halflife of 30.5 sec. Its ultrashort halflife and low radiation exposure (240 mrads to the kidney from a 20-mCi injection) make it an ideal agent for sequential first-transit studies of cardiac function. The reproducibility of ejection fraction and wall motion determinations were assessed from two gold-195m first-pass angiograms performed 3 min apart in 38 subjects. The accuracy of these evaluations was assessed by performing another first-transit study using technetium-99m. The correlation of the ejection fraction between the two gold-195m angiograms was 0.95 (standard error of the estimate (SEE) = 0.049) over an ejection fraction range of 20-78. The correlation of the ejection fraction using technetium-99m versus gold-195m was 0.95; SEE = 0.050. Only six minor discrepancies were noted when wall motion was evaluated in the gold-195m angiograms and compared with the technetium-99m study. We conclude that gold-195m can provide repeated, accurate, and reproducible ejection fraction and wall motion determinations with conventional imaging equipment at a substantially lower radiation exposure than with technetium-99m.

Angiography↗

PubMed1990

Chromosome aberration and sister chromatid exchange test results with 42 chemicals.

Forty-two chemicals were tested for their ability to induce cytogenetic change in Chinese hamster ovary cells using assays for chromosome aberrations (ABS) and sister chromatid exchanges (SCE). These chemicals were included in the National Toxicology Program's evaluation of the ability of four in vitro short-term genetic toxicity assays to distinguish between rodent carcinogens and noncarcinogens. The conclusions of this comparison are presented in Zeiger et al. [Zeiger E, Haseman JK, Shelby MD, Margolin BH, Tennant RW (1990): [Environ Molec Mutagen 16(Suppl 18): 1-14]. The in vitro cytogenetic testing was conducted at four laboratories, each using a standard protocol to evaluate coded chemicals with and without exogenous metabolic activation. Most chemicals were tested in a single laboratory; however, two chemicals, tribromomethane and p-chloroaniline, were tested at two laboratories as part of an interlaboratory comparison. Four chemicals (C.I. basic red 9 HCl, 2-mercaptobenzothiazole, oxytetracycline HCl, and rotenone) were tested for SCE in one laboratory and in a different laboratory for ABS. Tetrakis(hydroxymethyl)phosphonium sulfate was tested at one laboratory and the chloride form was tested at a different laboratory. Twenty-five of the 42 chemicals tested induced SCE. Sixteen of these also induced ABS; all chemicals that induced ABS also induced SCE. There was approximately 79% reproducibility of results in repeat tests, thus, we conclude that this protocol is effective and reproducible in detecting ABS and SCE.

Animals↗

PubMed1999

Three-dimensional color Doppler for assessing mitral regurgitation during valvuloplasty.

OBJECTIVE: Transesophageal color Doppler (or 2D Doppler) is the most widely used technique for intraoperative assessment of mitral valve repair. However, the most severe mitral regurgitations produce eccentric jet flows which cannot be assessed by 2D imaging. Up to now the indications for surgical intervention and intraoperative decisions after valve repair have been based on 2D Doppler examinations. Aim of this study was to compare conventional 2D Doppler to three-dimensional (3D) Doppler for assessing residual regurgitation in patients after mitral valvuloplasty. METHODS: Twenty-four patients were referred to surgery for mitral valve repair. They underwent transesophageal echocardiography and 3D data acquisition during mitral valve reconstruction. Conventional assessment of mitral valve regurgitation, measured by color Doppler jet area, was compared to the volume of regurgitant jets obtained by 3D Doppler. Regurgitant volume and fraction were measured by pulsed Doppler and two-dimensional echocardiography. The 3D reconstructions of color Doppler data were accomplished by means of the 'Heidelberg Raytracing Algorithm' developed at our institution. RESULTS: The jet areas did not show any significant correlation to the regurgitant fraction (r = 45; P = NS) or regurgitant volumes (r = 0.40; P = NS). In contrast the jet volumes correlated significantly to regurgitant fraction (r = 0.71; P < 0.01) and regurgitant volume (r = 0.85; P < 0.01). The reproducibility analysis of repeated jet volume and jet area measurements also showed that the parameter jet volume has a lower variability and higher agreement of repeated measurements than jet area. CONCLUSIONS: Three-dimensional color Doppler flow imaging revealed the complex geometry of eccentric regurgitant jets and showed that the assessment of mitral regurgitation, based on conventional 2D Doppler, can be misleading. This new technique has a great potential for becoming a reference method for assessing mitral valve repair.

Blood Flow Velocity↗