Certainty Of Interpretation Research Articles

Multidimensional Individualized Stuttering Therapy Outcomes At 24 Months Post Clinic: An Embodiment and Awareness Perspective.

Multidimensional Individualized Stuttering Therapy (MIST) is based on proactive collaborative work and shared decision making between client and clinician with the goal of identifying individual case-appropriate procedures and therapy elements in a manner that is meaningful and context-sensitive for each person. MIST combines value- and awareness-based elements from acceptance and commitment therapy (ACT) with stuttering and speech modification interventions. In keeping with the principles of ACT, we locate mindfulness as part of an embodied practice facilitated through a collaboration between the person who stutters and the speech-language therapist. The aim of this study was to see whether the positive results of MIST recorded at 12 months post-therapy remained stable at 24 months post-therapy and to consider the role of embodiment and awareness within MIST. Fifteen of 18 adults already enrolled in a treatment study (2015/FO12451) took part in a single-group repeated-measures design. They completed measures of stuttering severity, impact of stuttering, unhelpful thoughts and beliefs about stuttering, general anxiety symptoms, and fear of negative evaluation. There was a significant reduction of stuttering severity and negative impact of stuttering from pre-therapy to 24 months post-therapy. Unhelpful thoughts and beliefs about stuttering, symptoms of general anxiety, and fear of negative evaluation were reduced at 12 months post-therapy, and these values remained stable at 24 months post-therapy. MIST was associated with positive outcomes at 24 months post-therapy, suggesting a possible connection between the person-centered approach and longer-term benefit. Findings are discussed within the context of mindfulness and embodied adjustment, and shared client-clinician decision making. The absence of a control group is a limiting factor regarding certainty of interpretation. Future research is therefore needed on collaborative and individualized approaches to stuttering therapy that include embodiment and awareness perspectives.

Enhancing the diagnostic performance of CZT SPECT myocardial perfusion imaging with myocardial blood flow information

Abstract Background The use of cadmium-zinc-telluride (CZT) single photon emission computed tomography (SPECT) for measuring myocardial blood flow (MBF) has been established as a valuable tool for improving diagnostic accuracy. However, the clinical significance of incorporating MBF into the interpretation of stress SPECT myocardial perfusion imaging (MPI) remains largely unknown. Purpose The objective of this study is to determine the effect of MBF information on the interpretation of CZT SPECT MPI. Methods A cohort of 411 patients underwent a rest/stress gated perfusion and MBF imaging procedure using full-dose 99mTc-tetrofosmin. MBF and flow reserve were calculated using the Corridor4DM v2018 software (INVIA, Ann Arbor, MI). The SPECT data were analyzed twice, once without and once with MBF results. The criteria for abnormal myocardial flow reserve were set at 2.0, while stress flow was set at 1.8 ml/min/g. The interpretations were categorized into normal, equivocal, or abnormal and interpretive certainty was classified into five groups: definitely normal/abnormal, probably normal/abnormal, or equivocal. The overall results were evaluated, along with differences between men and women. Statistical significance was determined using contingency table analysis and chi-squared testing. Results The study cohort had a mean age of 62.5 ± 9.8 years, with 71% of the participants being male. The addition of MBF altered the MPI interpretation in 10.7% of patients (44/411), with a change from abnormal or equivocal to normal in 45.5% (20/44) of cases. The frequency of equivocal MPI interpretations dropped significantly from 4.6% without MBF to 1.5% with MBF (P=0.008). Interpretive certainty improved with a significant decrease in equivocal scans (P=0.006). 89.1% of MPI with MBF were reported as definitely normal or abnormal, compared to 83.0% without MBF (P=0.012) (Figure 1). Further analysis by gender showed similar results for men, while no significant changes were observed in women's MPI interpretation and certainty (Figure 2). Conclusion The inclusion of MBF had a significant impact on the interpretation of CZT SPECT MPI scans, with changes observed in 10.7% of cases. Interpretative certainty improved with fewer equivocal scans and a higher proportion of definitely normal or definitely abnormal interpretations. These findings were evident in men, but not in women (possible due to smaller sample size).Figure 1Figure 2

School of Practical Analytics: Analytical writing

This article is devoted to explaining the concept and meaning of applied analytical writing. The author outlines the requirements for analytical writing and explains some of them, including: analytical metacognitive distance; analytical insight; analytics maturity; evaluative and interpretive certainty; analytical fluency; analytical flexibility; analytical originality, analytical precision.

Multiple-pinhole collimators improve intra- and between-rater agreement and the certainty of the visual interpretation in dopamine transporter SPECT

BackgroundMultiple-pinhole (MPH) collimators improve the resolution–sensitivity trade-off compared to parallel-hole collimators. This study evaluated the impact of MPH collimators on intra- and between-rater agreement, and on the certainty of visual interpretation in dopamine transporter (DAT)-SPECT.MethodsThe study included 71 patients (62.1 ± 12.7 y). Two SPECT acquisitions were performed in randomized order after a single injection of 182 ± 9 MBq 123I-FP-CIT, one with MPH and one with low-energy–high-resolution–high-sensitivity (LEHRHS) collimators. MPH projections were reconstructed with an iterative 3d Monte Carlo algorithm. LEHRHS projections were reconstructed with filtered backprojection (FBP) or with ordered-subsets expectation–maximization and resolution recovery (OSEM). Images were visually evaluated twice by three independent raters with respect to presence/absence of Parkinson-typical reduction of striatal 123I-FP-CIT uptake using a Likert 6-score (− 3 = clearly normal, …, 3 = clearly reduced). In case of intra-rater discrepancy, an intra-rater consensus was obtained. Intra- and between-rater agreement with respect to the Likert score (6-score and dichotomized score) was characterized by Cohen’s kappa.ResultsIntra-rater kappa of visual scoring of MPH/LEHRHS-OSEM/LEHRHS-FBP images was 0.84 ± 0.12/0.73 ± 0.06/0.73 ± 0.08 (6-score, mean of three raters) and 1.00 ± 0.00/0.96 ± 0.04/0.97 ± 0.03 (dichotomized score). Between-rater kappa of visual scoring (intra-rater consensus) of MPH/LEHRHS-OSEM/LEHRHS-FBP images was 0.70 ± 0.06/0.63 ± 0.08/0.48 ± 0.05 (6-score, mean of three pairs of raters) and 1.00 ± 0.00/0.92 ± 0.04/0.90 ± 0.06 (dichotomized score). There was a decrease of (negative) Likert scores in normal DAT-SPECT by 0.87 ± 0.18 points from the LEHRHS-OSEM to the MPH setting. The (positive) Likert scores of reduced DAT-SPECT did not change on average.ConclusionsMPH collimators improve intra- and between-rater agreement as well as the certainty of the visual interpretation of DAT-SPECT.

De Novo ATP1A1 Variants in an Early-Onset Complex Neurodevelopmental Syndrome.

ATP1A1 encodes the α1 subunit of the sodium-potassium ATPase, an electrogenic cation pump highly expressed in the nervous system. Pathogenic variants in other subunits of the same ATPase, encoded by ATP1A2 or ATP1A3, are associated with syndromes such as hemiplegic migraine, dystonia, or cerebellar ataxia. Worldwide, only 16 families have been reported carrying pathogenic ATP1A1 variants to date. Associated phenotypes are axonal neuropathies, spastic paraplegia, and hypomagnesemia with seizures and intellectual disability. By whole exome or genome sequencing, we identified 5 heterozygous ATP1A1 variants, c.674A>G;p.Gln225Arg, c.1003G>T;p.Gly335Cys, c.1526G>A;p.Gly509Asp, c.2152G>A;p.Gly718Ser, and c.2768T>A;p.Phe923Tyr, in 5 unrelated children with intellectual disability, spasticity, and peripheral, motor predominant neuropathy. Additional features were sensory loss, sleep disturbances, and seizures. All variants occurred de novo and are absent from control populations (MAF GnomAD = 0). Affecting conserved amino acid residues and constrained regions, all variants have high pathogenicity in silico prediction scores. In HEK cells transfected with ouabain-insensitive ATP1A1 constructs, cell viability was significantly decreased in mutants after 72h treatment with the ATPase inhibitor ouabain, demonstrating loss of ATPase function. Replicating the haploinsufficiency mechanism of disease with a gene-specific assay provides pathogenicity information and increases certainty in variant interpretation. This study further expands the genotype-phenotype spectrum of ATP1A1.

Changing Threshold-Based Segmentation Has No Relevant Impact on Semi-Quantification in the Context of Structured Reporting for PSMA-PET/CT.

Simple SummaryMolecular imaging of patients with prostate cancer is widely utilized. We aimed to determine whether changes in post-processing parameters, such as maximum intensity thresholds, can significantly alter results. We investigated 623 lesions that were positive on a molecular imaging scan and could not find any relevant impact on results when certain parameters were changed, in particular in lesions indicative for metastases of prostate cancer.Prostate-specific membrane antigen (PSMA)-directed positron emission tomography/computed tomography (PET/CT) is increasingly utilized for staging of men with prostate cancer (PC). To increase interpretive certainty, the standardized PSMA reporting and data system (RADS) has been proposed. Using PSMA-RADS, we characterized lesions in 18 patients imaged with 18F-PSMA-1007 PET/CT for primary staging and determined the stability of semi-quantitative parameters. Six hundred twenty-three lesions were categorized according to PSMA-RADS and manually segmented. In this context, PSMA-RADS-3A (soft-tissue) or -3B (bone) lesions are defined as being indeterminate for the presence of PC. For PMSA-RADS-4 and -5 lesions; however, PC is highly likely or almost certainly present [with further distinction based on absence (PSMA-RADS-4) or presence (PSMA-RADS-5) of correlative findings on CT]. Standardized uptake values (SUVmax, SUVpeak, SUVmean) were recorded, and volumetric parameters [PSMA-derived tumor volume (PSMA-TV); total lesion PSMA (TL-PSMA)] were determined using different maximum intensity thresholds (MIT) (40 vs. 45 vs. 50%). SUVmax was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories (p ≤ 0.0322). In particular, the clinically challenging PSMA-RADS-3A lesions showed significantly lower SUVmax and SUVpeak compared to the entire PSMA-RADS-4 or -5 cohort (p < 0.0001), while for PSMA-RADS-3B this only applies when compared to the entire PSMA-RADS-5 cohort (p < 0.0001), but not to the PSMA-RADS-4 cohort (SUVmax, p = 0.07; SUVpeak, p = 0.08). SUVmean (p = 0.30) and TL-PSMA (p = 0.16) in PSMA-RADS-5 lesions were not influenced by changing the MIT, while PSMA-TV showed significant differences when comparing 40 vs. 50% MIT (p = 0.0066), which was driven by lymph nodes (p = 0.0239), but not bone lesions (p = 0.15). SUVmax was significantly higher in PSMA-RADS-5 lesions compared to all other PSMA-RADS categories in 18F-PSMA-1007 PET/CT. As such, the latter parameter may assist the interpreting molecular imaging specialist in assigning the correct PSMA-RADS score to sites of disease, thereby increasing diagnostic certainty. In addition, changes of the MIT in PSMA-RADS-5 lesions had no significant impact on SUVmean and TL-PSMA in contrast to PSMA-TV.

CONTRADICTIONS IN INTERPRETATION OF INTERNATIONAL ARBITRATION AGREEMENTS

This article explores a divergence of approaches applicable to interpretation of arbitration agreement due to the very nature of international commercial arbitration as transnational and multicultural forum. The author also considers globalization of international commerce as a key factor in promoting predictability and certainty of contractual interpretation and thereby promoting uniformity in its approaches. The interaction between the diversity of legal cultures, on the one hand, and demand for uniformity, on the other hand, are at stake in this discussion. Keywords: diversity, uniformity, arbitration agreement, interpretation, internationalcommercial arbitration, intention of the parties, validity, scope of arbitration agreement, national courts.

Eisenstein’s Ivan the Terrible, Indeterminacy, and the Hermeneutics of Suspicion

This essay praises Joan Neuberger’s book This Thing of Darkness (Cornell University Press, 2019) as a great accomplishment in cinematic interpretation and a detailed and subtle historical account. It contests Neuberger’s argument that Eisenstein’s Ivan the Terrible films present an unequivocal critique of Stalin and Stalinism by means of a historical analogy with Ivan. Platt argues that the films are intentionally, stubbornly ambivalent in their representation of Ivan, and by extension Stalin. He contends that although this was indeed a subversive movie in the Stalinist USSR, Eisenstein’s films did not offer any finalized conception of the historical role of these figures, and instead should be viewed as works that thematize the impossibility of achieving certainty in historical interpretation. In reading Neuberger’s This Thing of Darkness, one feels the urgency of the author’s efforts to prove that Eisenstein offered an unequivocal, “radical” and “subversive” denunciation of Stalin and the social violence of his era — one that accords with our own rejection of the Stalinist legacy. Author sympathizes with this effort, but it is misguided. Considered in his own social context, one cannot but appreciate Eisenstein’s bravery in articulating a different, but no less subversive position: as seen through the lens of Ivan the Terrible, Stalinist Russia was revealed to be incomplete, charged with contradictions that made it impossible to come to conclusions concerning the meaning of events.

Critical Analysis of Literal Rule of Interpretation

The Literal Rule of Interpretation is the oldest rule and is followed to date by the Judges across the globe. The rationale behind the Literal Rule is that it prevents courts from making biased decisions when the issue is relating to political matters. This rule also restricts the Courts from creating new laws through the interpretation of the existing ones. This rule follows the words of the Legislature and implication of this rule brings certainty in interpretation as the law would be interpreted exactly as it is provided by the Legislature. As every coin has two sides, there are some disadvantages of applying the Literal Rule of Interpretation. This at times results in the provisions being vague and absurd and inconsistent with the intention of the framers of the Statute. There cannot be a fixed rule for Interpretation and similarly, a statute cannot be drafted without having multiple interpretations. As Justice Donaldson contended, “the interpretation of statutes is a craft as much as a science and the judges, as craftsmen, select and apply the appropriate rules as the tools of their trade”.

Комплексний магнітоваріаційний та тектономагнітний моніторинг сучасної геодинаміки західного схилу Антарктичного півострова

Aim – investigations of effectiveness and information value of tectonomagnetic and magnetic-variations monitoring complex to study the recent geodynamics of Antarctic Peninsula in the location of Akademik Vernadsky station. Methodology. The methodology provides long-term magnetic variations observations on the Akademik Vernadsky station. On the base of observations electromagnetic induction vector components (Wise vector) are processing in the range 2.5—60 min. Series of this parameters temporal variations are developing. Tectonomagnetic observations are performed on the stationary network of observational points on the Antarctic geodynamic polygon and then, tectonomagnetic anomalies (increasing of a local magnetic field among observational epochs-total magnetic field vector module) is defined. The nature of tectonomagnetic anomalies usually is connected with variations of tectonic tensions. Compounding of magnetic variations and tectonomagnetic observations allows to upgrade certainty of tectonophysic interpretation of geophysical and geological data for investigations of Antarctic Peninsula recent geodynamics. Results. The results of tectonomagnetic and magnetic variations observations on the Akademik Vernadsky station in the location of Antarctic tectonomagnetic polygon during 1998—2017 yrs. were analyzed and generalized. Temporal variations of Wise electromagnetic induction vectors and local geomagnetic field variations were investigated. Anomalous effects in tectonomagnetic variations and Wise vectors temporal variations, caused by seismotectonic processes in the region’s lithosphere were defined. Comparative analyses of tectonomagnetic and magnetic variations data was done. Also was justified possibility their complex for monitoring of recent seismotectonic processes in the location of Akademik Vernadsky station. Conclusions. Complex analyses of long-term tectonomagnetic field and magnetic variations parameters on the Akademik Vernadsky station was done. Correlation between tectonomagnetic effects on the Antarctic geodynamic polygon and anomalous effects in Wise vectors temporal series was defined. Such complex of tectonomagnetic and magnetic variations monitoring is organic and allows to obtain reliable information about Antarctic Peninsula geodynamics in connection with seismic and other geophysical methods.

Style, Computers, and Early Modern Drama: Beyond Authorship. Hugh Craig and Brett Greatley-Hirsch. Cambridge: Cambridge University Press, 2017. Pp. vii+283.

<i>Style, Computers, and Early Modern Drama: Beyond Authorship</i>. Hugh Craig and Brett Greatley-Hirsch. Cambridge: Cambridge University Press, 2017. Pp. vii+283.

Mineralogical and geochemical evidence of weathering in a middle to late Pleistocene paleosol sequence in the Driftless Area of Wisconsin

AbstractPaleosols occur in the Driftless Area of southwestern Wisconsin because this area escaped direct Pleistocene glaciation, allowing long-term loess and colluvium accumulation in selected settings. The most complete known depositional sequence at Oil City, Wisconsin, contains eight lithologic units with five paleosols, all with normal remanent magnetism (i.e., &lt;780 ka). Previous work characterized the stratigraphy, pedology, micromorphology, and clay mineralogy of the section. We investigate chemical weathering of the 8–63 µm silt fraction using X-ray diffraction (XRD) and elemental geochemistry by portable X-ray fluorescence (pXRF). Elemental ratios TiO2/CaO, Zr/Sr, and Rb/Sr generally align with the pedological evidence of weathering. Mineral ratios plagioclase/quartz and K-feldspar/quartz display greater scatter and less certainty in interpretation. The paleosols with Bt horizons have ratios indicating greater weathering than the modern soil. The most weathered paleosol is formed in the unnamed fourth loess unit stratigraphically below the Loveland Member. The stratigraphic position and higher degree of weathering support correlation of the fourth loess with the Yarmouth Geosol and Crowley’s Ridge Silt of the Middle Mississippi valley. Geochemical indices by pXRF are more consistent with established lithologic breaks than mineralogy by XRD. Our results support the use of pXRF for stratigraphic and weathering studies of Quaternary sediments.

Comparative accuracy of supine-only and combined supine-prone myocardial perfusion imaging in men

BackgroundCombined supine-prone myocardial perfusion imaging (CSP MPI) has been shown to reduce attenuation artifact in comparison to supine-only (SU) MPI in mixed-gender populations with varying risk for coronary artery disease (CAD), often where patients served as their own controls. However, there is limited direct comparison of these imaging strategies in men. Methods934 male patients underwent CSP or SU MPI. Diagnostic certainty of interpretation was compared. Within the cohort, 116 were referred for left heart catheterization (LHC) to assess for CAD. Sensitivity, specificity, and area under the curve (AUC) were compared with additional analysis based on body mass index (BMI). Results597 patients completed the SU protocol and 337 patients completed the CSP protocol. Equivocal studies were seen more frequently in the SU group (13%) than in the CSP group (4%, P < .001). At catheterization, the specificity for CSP MPI of 70% was higher than 40% for SU MPI (P = .032). The CSP AUC (0.80 ± 0.06) was significantly larger than SU AUC (0.57 ± 0.05, P = .004). CSP specificity was significantly higher in obese patients. ConclusionsCSP MPI increases diagnostic certainty and improves test accuracy for CAD detection in men with CAD risk factors, especially obese patients, compared to SU MPI.

Restrictions on Disposition in the Oil and Gas Industry: The Extinction of the Species?

Restrictions on disposition in the oil and gas industry, predominantly rights of first refusal, can create significant uncertainties in oil and gas transactions, particularly complex ones. In an effort to discern trends in judicial approaches, the authors review Canadian jurisprudence dealing with difficult rights offirst refusal issues against the backdrop of academic and professional commentary in the 1990s, which promoted the establishment of judicially developed "default rules" to ensure interpretive certainty. The authors postulate that parlies ought not to presume the existence or application of "default rules" in the interpretation and application of restrictions on disposition, based on the jurisprudence. Rather. parties ought to focus on considered drafting when preparing agreements and. where uncertainties arise defaut in the application of provisions, ought to contemplate the reasonable expectations of the parties to the agreement.

Evaluating the Role of Routine Prone Acquisition on Visual Evaluation of SPECT Images.

Attenuation artifacts reduce our ability to evaluate perfusion of affected myocardial segments. The aim of this study was to evaluate the impact of routine prone-position image evaluation within a stepwise visual interpretation of myocardial perfusion studies. We have included 279 consecutive patients who were referred for evaluation of myocardial ischemia. All patients underwent routine electrocardiogram-gated supine SPECT imaging and non-electrocardiogram-gated prone-position SPECT imaging. Three nuclear medicine physicians interpreted the images in the following order: polar maps, supine images, raw images, motion-frozen gated images, and prone images, using a scale of 0-4. Segments with perfusion abnormalities were noted. All physicians reported lower proportions of equivocal evaluations after evaluating prone images (18.3% vs. 4.7%, 19% vs. 11.1%, and 12.2% vs. 6.1%, P < 0.0001, P = 0.0077, and P = 0.0125, respectively). At the prone stage, normalcy rates were 89%, 87%, and 91%. Two physicians had significantly increased normalcy rates at the prone stage (72%-89%, P = 0.039, and 66%-87%, P = 0.006). At the prone stage, a decision reversal to normal or probably normal was observed in 40% (29/72), 33% (17/51), and 43% (21/48). In men, apical, mid, and basal inferior walls and in women apical and mid parts of anterior walls were more likely to be attributed to attenuation. The 2 steps that increased normalcy rates for interpreters were the review of raw images and of prone images. Routine prone imaging increases interpretive certainty and interobserver agreement and changes the final evaluation in a substantial number of patients and significantly decreases the number of equivocal evaluations.

Język przedstawiony, czyli świat współczesnej prozy

The article is dealing with the place taken by language reflection in modern literary theory. Poststructural breakthrough in the Humanities had become a period of opening up to new inspiration, and most of all to “language learning”. Much more important than the direct impact of the deconstruction was a change of consciousness: hereby the structuralist paradigm as the dominant way of talking about literature became exhausted. One academic discourse was replaced by the multitude of languages , and the multiplicity of rhetoric. The certainty of interpretation was replaced by interpretative doubts. That distrust embraced everything: not only the methodology, but the literature itself. A literary work ceased to be an objective structure, and its meaning a function of order. In this situation of discipline language, as art material, becomes the object of special attention of authors and researchers. The significance of language experiments is present in modern Polish prose, especially in prose by Wieslaw Myśliwski.

The influence of coronary calcium score on the interpretation of myocardial perfusion imaging

PurposeCoronary artery calcium (CAC) scores influence the pre-test likelihood of ischemia in patients undergoing myocardial perfusion imaging (MPI). We investigated the influence of CAC score knowledge on the visual interpretation of MPI in patients referred for the diagnostic work-up of suspected coronary artery disease. MethodsWe retrospectively analyzed symptomatic patients who were referred for MPI. For the current analysis, we selected 151 patients who underwent SPECT MPI with simultaneous CAC scoring. MPI was visually interpreted in two separate sessions, first without and then with knowledge of the CAC score. MPI results were classified into four groups: normal, fixed defects, ischemia, and equivocal. ResultsMean age of the patients was 64 ± 11 years, 56 % were male. Without knowledge of the CAC score MPI was evaluated as normal in 36 %, compared to 40 % with knowledge of the CAC score (P = 0.636). Overall, the addition of the CAC score changed the interpretation of MPI in 56 patients (37 %). Importantly, the frequency of equivocal MPI interpretations decreased from 21 % without knowledge of CAC score to 9 % with knowledge of CAC score (P = 0.002). ConclusionsKnowledge of the CAC score has a major impact on the interpretation of MPI, increasing the interpretative certainty.

Constraining Stochastic Inversion with Frequency Domain Seismic Signature for Seismically Thin-bed Interpretation

An alternative technique in interpreting thin-bed structure has been developed. The technique involved stochastic inversions which use frequency domain energy spectral attribute as a constraint instead of time domain seismic amplitude. Maximum Amplitude Weighed Integrated Energy Spectra is a proposed energy spectral attribute which was used to constrain the stochastic process. Amplitude Weighed Integrated Energy Spectra is a deployed seismic attribute obtained by multiplying integrated energy spectra with maximum amplitude of a seismic trace. It is shown that Amplitude Weighed Integrated Energy Spectra provides a more separable signature in responding to bed thickness changes than seismic signature. A lower degree of ambiguity of Amplitude Weighed Integrated Energy Spectra in sensing thin-bed seismic is a potential method of reducing thin bed interpretation uncertainty. Qualitatively, Amplitude Weighed Integrated Energy Spectra is capable of showing one of the reported very thin meandered channel complexes of gas reservoir of Stratton field which is difficult to be seen in seismic amplitude. In this research, Amplitude Weighed Integrated Energy Spectra is incorporated in a stochastic seismic inversion to improve both accuracy and precision (certainty) of thin-bed interpretation. The signature of Amplitude Weighed Integrated Energy Spectra is used to constrain the degree of match (likelihood) between seismic model and data. Synthetic data testing shows that the proposed method significantly improves both accuracy and precision of a single wedge model seismic inversion. The thickness and reflection coefficient are estimated more accurately, although limited information is used. The proposed method was tested to invert a structurally subtle gas production zone of Stratton field. Confirmed by well log data, a cross section of inverted impedance showed that some channel complex structure of gas reservoirs are able to be imaged.

Diagnostic accuracy of high-resolution attenuation-corrected Anger-camera SPECT in the detection of coronary artery disease

BackgroundThere is limited data on diagnostic accuracy of recently introduced high-resolution Anger (HRA) SPECT incorporating attenuation correction (AC), noise reduction, and resolution recovery algorithms. We therefore studied 54 consecutive patients (excluding those with prior MI or cardiomyopathy) who had HRA-AC SPECT and coronary angiography (CA) ≤ 30 days and no change in symptoms. MethodsThe HRA-AC studies were acquired in 128 × 128 matrix (3.2 mm pixel) format with simultaneous Gd-153 line-source AC. Measured variables were image quality, interpretive certainty, sensitivity and specificity for any CAD, sensitivity for single- and multivessel CAD, and the influence of gender, body mass index (BMI), and stress modality. ResultsThe mean age of the patients was 66 ± 11 years with a BMI of 32 ± 7 kg·m−2. Mean interpretive certainty score was 2.7 on a 3-point scale and mean image quality score was 3.3 on a 4-point scale. Stress perfusion defects were detected in 34 of 38 patients with obstructive CAD [sensitivity 89%, 95% confidence interval (CI) 76%-95%]. The specificity was 75% (CI 51%-90%) and overall diagnostic accuracy was 85% (CI 73%-92%). Accuracy did not differ for females vs males, for BMI ≤30 vs >30, or for pharmacologic vs exercise SPECT. Sensitivity for single-vessel disease was 88% (CI 69%-96%) and for multivessel disease was 93% (CI 69%-99%). ConclusionNew Anger technology incorporating innovative improvements results in high image quality with excellent interpretive certainty and high diagnostic accuracy.

The influence of SPECT reconstruction algorithms on image quality and diagnostic accuracy in phantom measurements and 99mTc-sestamibi parathyroid scintigraphy

The aim of the study was to determine the influence and clinical consequences of different tomographic reconstruction algorithms on the image quality and diagnostic accuracy of low count statistics single photon emission computed tomography (SPECT). Phantom scans were used to assess the image quality (percentage of recovered contrast, relative noise level, and spatial resolution). The diagnostic accuracy of parathyroid SPECT performed in 60 patients with primary hyperparathyroidism was assessed. Phantom and patient SPECT scans were reconstructed by two different algorithms (ReSPECT and HOSEM). Two blinded nuclear medicine physicians interpreted the patient scans in random order, without knowledge of any clinical data. Subjective image quality and certainty of diagnosis were scored. Significantly lower relative noise levels (0.08 vs. 0.13, respectively; P=0.042) and higher image spatial resolution (6.6 vs. 17.1 mm full-width at half-maximum in the transaxial plane, respectively) were found in the phantom studies using ReSPECT as compared with HOSEM. In the clinical scans, the mean target-to-background ratio was higher for ReSPECT (4.53 vs. 2.97; P<0.001). There was no significant difference in region-based sensitivity (73 vs. 68%; P=0.538) or specificity (93 vs. 92%; P=0.815) between ReSPECT and HOSEM. Subjective image quality as well as certainty of interpretation was higher for ReSPECT (P<0.001). There is a significant difference in image quality between commercially available algorithms for tomographic reconstruction of SPECT scans, which appears to have an impact on diagnostic accuracy and interpreter certainty. Therefore, we believe that a systematic comparison of different SPECT reconstruction algorithms should be made to ensure reproducible high image quality in clinical SPECT.