Unilateral VQ mismatch from pulmonary embolism detected on VQ scintigraphy with SPECT/CT: a case report
Bibliographic record
Abstract
Abstract Background We describe a case of unilateral whole-lung VQ mismatch caused by a right main pulmonary artery PE, equivocal on pseudoplanar VQ scintigraphy, highly suspected on VQ SPECT/CT scintigraphy and confirmed on CT angiography. This case confirms the well-established notion that SPECT and SPECT/CT provide significant improvement in diagnostic performance compared to planar imaging in such cases. Case presentation Pseudoplanar VQ scintigraphy identified a unilateral right lung VQ mismatch and was doubtful on the presence of a left-sided subsegmental mismatch, ultimately equivocal for pulmonary embolism given the vast differential of unilateral VQ mismatches. SPECT allowed for definitive identification of a contralateral lung VQ segmental mismatch, and low-dose CT did not reveal an alternative diagnosis to explain the unilateral right-sided whole-lung VQ mismatch. Conclusion In our case, pseudoplanar imaging alone was insufficient to make a certain diagnosis of PE. However, SPECT confirmed a significant contralateral lung VQ mismatch and low-dose CT did not reveal an alternate cause of the VQ mismatch, together highly suggestive of PE, supporting the potentially added value of SPECT and CT in such cases.
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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 | 0.001 | 0.007 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.004 | 0.002 |
| Science and technology studies | 0.002 | 0.003 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.008 | 0.004 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".