Nongated Photon-Counting Computed Tomography Angiography Detects Cardioembolic Stroke Sources and Thoracic Pathology:...

Stroke is often attributable to cardiothoracic factors, but the need for ECG gating and limited spatial resolution on conventional computed tomography often limits the detection of pathology relevant for secondary stroke prevention. The study objective was to evaluate the frequency of cardiothoracic pathology on non-ECG-gated photon-counting computed tomography angiography during initial stroke imaging.

Consecutive patients with a clinical suspicion of acute stroke, who were imaged using non-ECG-gated dual-source photon-counting computed tomography with diaphragm-to-vertex coverage at a comprehensive stroke center, were retrospectively included. Image quality was assessed using a 4-point Likert scale, and images were evaluated for cardiac stroke sources and thoracic pathology. Where available, results from echocardiography were collected.

The study included 193 complete stroke investigations, 126 of which (65.3%; 95% CI: 58.3-71.6) had imaging-confirmed ischemic strokes. The image quality was generally high for cardiac imaging (excellent 9.8% [95% CI: 6.4-14.9], good 50.3% [95% CI: 43.3-57.2], moderate 37.3% (95% CI: [30.8-44.3]), poor 2.6% [95% CI: 1.1-5.9]) and thoracic imaging (excellent 7.8% [95% CI: 4.8-12.4]), good 59.6% [95% CI: 52.5-66.3]), moderate 32.6% [95% CI: 26.4-39.5]), poor 0% [95% CI: 0.0-2.0]). Clinically relevant cardioembolic findings were detected in 4.7% (95% CI: 2.5-8.6) of all patients: 6 cardiac thrombi (3.1%; 95% CI: 1.4-6.6), 3 aortic valve vegetations (1.6%; 95% CI: 0.5-4.5). Other findings that could affect patient management were detected in 31.6% (95% CI: 25.5-38.5) of scans, including 14 patent foramen ovale (7.3%; 95% CI: 4.4-11.8), 13 pulmonary embolisms (6.7%; 95% CI: 4.0-11.2), 29 pleural effusions (15.0%; 95% CI: 10.7-20.7), and 8 lung malignancies (4.1%; 95% CI: 2.1-8.0). Cardiac thrombi and vegetations were exclusively found in the ischemic stroke subgroup.

Cardiothoracic pathology relevant to patient management or secondary stroke prevention was commonly detected with good diagnostic image quality as part of the standard stroke imaging workup with non-ECG-gated high-pitch dual-source photon-counting computed tomography angiography.