Comparison of Planar and 3-Dimensional Methods for Quantification of Differential Renal Function Using <sup>99m</sup> Tc-DMSA and <sup>99m</sup> Tc-Glucoheptonate Renal Scintigraphy
Bibliographic record
Abstract
This study aims to determine whether the calculation of the differential renal function (DRF) for renal scintigraphy using volumetric assessment is equivalent to conventional planar assessment using the geometric mean. Methods: A retrospective study was conducted with 108 patients referred for cortical renal scintigraphy. Forty-five patients were injected with 99mTc-dimercaptosuccinic acid (DMSA), and 63 patients were injected with 99mTc-glucoheptonate and furosemide, depending on which radiotracer was available at the time of the examination. DRF was measured using automatic 3-dimensional volume-of-interest delineation software on SPECT and 2-dimensional manual regions of interest on planar images, with geometric mean calculated for all patients. Images were reviewed by 2 independent masked observers. To assess intrarater reliability, a random sample of 20 images (10 with 99mTc-DMSA and 10 with 99mTc-glucoheptonate) was reprocessed by the same observers to after a minimum 2-wk interval to minimize recall bias. Values obtained by planar and SPECT methods were compared using a paired Student t test. Reproducibility was assessed through intraobserver and interobserver analyses using the intraclass correlation coefficient. Results: There was a significant difference in DRF values obtained by planar and SPECT methods with both 99mTc-glucoheptonate and 99mTc-DMSA (P < 0.05), with maximum absolute differences of 40.0% and 13.0%, respectively. High intrarater and interrater intraclass correlation coefficients were obtained for both methods and radiotracers (>0.9), indicating excellent reliability. Conclusion: The SPECT quantification method for the evaluation of DRF is reliable because of high intraobserver and interobserver agreement. Furthermore, it differs significantly from the planar quantification method, with more pronounced differences observed with 99mTc-glucoheptonate compared with 99mTc-DMSA.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.006 | 0.024 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".