Spectral Cardiac CT in Acute Stroke
(2023)Objective
To assess the diagnostic value of spectral (dual energy) cardiac CT reconstructions compared to conventional CT for detecting intra-cardiac thrombi in acute ischemic stroke patients.
Study Summary
Intervention
Delayed-phase ECG-gated cardiac CT using dual-layer spectral CT. Reconstructions included conventional images, monoenergetic (monoE55), z-effective (zeff), and iodine density images.
Inclusion Criteria
Acute ischemic stroke patients with large vessel occlusion, scanned with a multimodal CT protocol including spectral cardiac CT.
Study Design
Arms: Single-arm retrospective comparison between spectral and conventional reconstructions.
Patients per Arm: 63 patients; 20 thrombi detected in 15 patients.
Outcome
Bottom Line
Spectral cardiac CT, particularly virtual monoenergetic and iodine density images, provides additional diagnostic benefit for detecting intracardiac thrombi in acute ischemic stroke patients compared to conventional CT alone, with improved contrast and diagnostic certainty.
Major Points
- This retrospective study evaluated the diagnostic value of spectral cardiac CT compared to conventional CT for detecting cardiac thrombi in 63 acute ischemic stroke patients.
- Four intracardiac thrombi (20% of the total) were missed on conventional CT images but were detected on spectral reconstructions.
- Virtual 55 keV monoenergetic (monoE55) images achieved the highest scores for diagnostic certainty in detecting thrombi.
- Iodine density images provided the highest contrast ratios between the cardiac lumen and soft tissue, followed by monoE55 reconstructions.
- The study suggests that incorporating spectral cardiac CT into a one-stop-shop stroke CT protocol can aid in the timely detection of cardioembolic sources.
Study Design
- Study Type
- Retrospective study.
- Randomization
- No
- Blinding
- Two independent readers, blinded to clinical data, assessed the images.
- Sample Size
- 63
- Follow-up
- Not applicable.
- Centers
- 1
- Countries
- Germany
Primary Outcome
Definition: Detection rate of intra-cardiac thrombi.
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 80% (16/20) | 95% (19/20) with monoE55, 50% (10/20) with zeff, 85% (17/20) with iodine density | - |
Limitations & Criticisms
- The study was retrospective and had a small sample size, which limited the ability to perform subgroup analyses.
- Lack of a reference standard for diagnosing intra-cardiac thrombi in a sufficient number of patients prevented the calculation of sensitivity and specificity.
- The use of cardiac CT involves radiation exposure and contrast agent administration, which poses a potential risk to patients, although this risk is likely less relevant in an older patient population.
Citation
Scientific Reports | (2023) 13:6781