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Record W4318344211 · doi:10.1136/heartjnl-2022-bscmr.9

9 A comparison between three quantitative perfusion post processing methods

2023· article· en· W4318344211 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueAbstracts · 2023
Typearticle
Languageen
FieldMedicine
TopicCardiac Imaging and Diagnostics
Canadian institutionsCircle Cardiovascular Imaging
FundersUniversity of LeedsBritish Heart Foundation
KeywordsPerfusionMedicineParametric statisticsNuclear medicineComputer scienceInternal medicineMathematicsStatistics

Abstract

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<h3></h3> Several analysis methods for Quantitative Perfusion (QP) CMR have been proposed, some vendor-specific, others generic. Published literature shows differences in the Myocardial Blood Flow (MBF) between these methods. Current limitations include the lack of consensus on optimal acquisition and analysis techniques, which ideally, should yield MBF and myocardial perfusion reserve (MPR) estimates consistent with, and interchangeable across studies and preferably with PET, which remains the gold-standard [1]. There lack of inter-vendor standardisation remains an important hinderance for the implementation of QP CMR into routine clinical practice. We investigated the differences in global stress MBF, global rest MBF and myocardial perfusion reserve (MPR) between three post-processing quantitative perfusion methods using two field strengths. 27 patients referred for stress myocardial perfusion CMR were recruited. Basic demographic data and CMR data was collected. Two scanners (1.5T Ingenia and 3T Achieva-TX were used. Both sequences used dual acquisition protocols and comparable contrast-agent dosing regimens. Data from both field strengths were grouped and then analysed using 3 different QP methods (A [2], B [3] and C [4] to derive global rest MBF, global stress MBF and MPR. The data were tested for normality and then methods were compared with one another using repeated measures one way ANOVA for parametric data, or Friedman’s test for non-parametric data, as appropriate. All patients completed studies with good quality. 20 scans were performed on 1.5T and 7 scans were performed on 3T. Mean Ejection fraction was 55 ±11%, mean age was 65 ±10 years with a male: female distribution (22:5). Mean global stress MBF, rest MBF and MPR for method A were 2.38 ± 0.82 [2.06–2.70], 1.35± 0.55 [1.13–1.56] and 1.98± 0.61 [1.73–2.22] for method B were 2.43 ±0.55 [2.21–2.65], 1.28 ±0.59 [ 1.05–1.51] and 2.02 ± 0.60 [1.78–2.26] and for method C were 2.89 ± 0.50 [2.70–3.09], 1.36± 0.49 [1.17–1.56] and 2.25± 0.55 [2.04–2.45] respectively. There was no statistically significant difference in MPR using the three methods (F(2,52) =2.39, p=0.102) or in rest MBF (X<sup>2</sup>(2) = 0.92, p= 0.63). Statistically significant differences in stress MBF (F (2,52) =7.36, p=0.002) were seen. Preliminary analysis of QP at two field strengths and between three analysis methods suggests significant differences in stress MBF results between some QP methods. However, MPR may have better reproducibility. Further studies are required between more QP techniques, incorporating multiple vendor QP implementations to determine clinical utility of QP and for international standardisation.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.002
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.370
Threshold uncertainty score0.604

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.106
GPT teacher head0.459
Teacher spread0.353 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it