Newer imaging modalities for evaluation of coronary atherosclerosis

Newer imaging modalities for evaluation of coronary atherosclerosis

Some of the newer imaging modalities for assessing coronary atherosclerosis beyond conventional coronary angiography, CT coronary angiography and intravascular ultrasound are:

1. OCT: Optical coherence tomography
2. NIRS: Near-infrared spectroscopic imaging
3. Intravascular magnetic spectroscopy
4. Intravascular magnetic resonance imaging
5. IVPA: Intravascular photoacoustic imaging
6. NIRF: Near-infrared fluorescence imaging
7. TRFS: Time resolved fluorescence spectroscopic imaging

Of these, OCT is available for use in many centers across the globe while most of the other modalities are still available only as research tools. Each modality can have its own advantages. If IVUS can image beyond lipid rich plaques, OCT can penetrate calcified plaques.

NIRS gives a ‘chemogram’ of the coronary arterial wall and is useful in detecting lipid rich plaques. Lipid rich plaques are frequent in culprit lesions of patients with acute coronary syndromes. They are also common in non culprit lesions in patients with acute coronary syndromes compared to those with stable coronary artery disease [1].

A study published in 2022 compared qualitative angioscopic findings with objective and quantitative NIRS assessement. Those undergoing planned follow up coronary angiography after percutaneous coronary intervention were enrolled. They concluded that qualitative angioscopic assessment could be objectively validated with quantitative NIRS evaluation, which would be helpful for reinterpretation of existing evidences of both imaging modalities [2].

References

1. Milosz Jaguszewski, Roland Klingenberg, Ulf Landmesser. Intracoronary Near-Infrared Spectroscopy (NIRS) Imaging for Detection of Lipid Content of Coronary Plaques: Current Experience and Future Perspectives. Curr Cardiovasc Imaging Rep. 2013;6(5):426-430.
2. Omatsu T, Sotomi Y, Kobayashi T, Hamanaka Y, Hirata A, Hirayama A, Ueda Y, Sakata Y, Higuchi Y. Quantitative Validation of the Coronary Angioscopic Yellow Plaque with Lipid Core Burden Index Assessed by Intracoronary Near-Infrared Spectroscopy. J Atheroscler Thromb. 2022 Mar 1;29(3):362-369. doi: 10.5551/jat.60566. Epub 2021 Jan 22. PMID: 33487618; PMCID: PMC8894116.