The clinical value of quantitative cardiovascular molecular imaging: a step towards precision medicine

Figure 1.. Illustrative image regarding dynamic PET acquisition and parametric image analysis using an LAFOV PET/CT system in cardiovascular disease. Dynamic imaging was performed using an LAFOV PET/CT scanner with a 106 cm field-of-view in this patient with suspected vasculitis. A 65 min dynamic acquisition was started simultaneously with the intravenous injection of [18F]FDG. PET data were reconstructed using 31 frames as follows: 6 × 10 sec, 3 × 20 sec, 6 × 30 sec, 5 × 1 min and 11 × 5 min. Series A through D shows different frames: frame 4, 30–40 sec (a), frame 15, 270–300 sec (b), frame 23, 20–25 min (c) and frame 31, 60–65 min (d). In D, arrows indicate three regions suspicious for vasculitis: red for the ascending aorta, green for the aortic arc and blue for the carotid artery. E shows the time activity curve for the different volumes of interest: the three vasculitis regions, the liver reference region and the descending aorta (which is also the image derived arterial input curve). F shows a schematic of Patlak linearisation using the image derived input curve from the descending aorta and the different tissue time activity curves from E to obtain the net influx rate (Ki). G shows…

Figure 2.. Example output of the cardiovascular system from an artificial intelligence segmentation model. Different sections of the cardiovascular system can be segmented from CT scans. These segmentations can be used to quantify radiotracer uptake in the specific regions. This may possibly speed up quantitative research in cardiovascular diseases tremendously and potentially provide accurate and standardised quantitative analyses of these diseases for primary diagnosis and disease monitoring. Output results should be properly checked and adjusted if needed (see iliac artery). Segmentations are acquired with a previously published, open-source AI model from Wasserthal et al. 36 AI = artificial intelligence.

Figure 3.. Example case of a serial [99mTc]-DPD bone scintigraphy in a wild type ATTR amyloidosis patient. Whole body anterior planar images before (a) and after (d) 6 months treatment with 61 mg tafamidis and quantitative SPECT/CT scans before (b) and after (c) treatment. Visual assessment of planar images suggests a decrease in cardiac tracer uptake despite unchanged Perugini score, this decrease is reflected by a decrease in myocardial SUVmax and myocardial TBR on quantified SPECT scans indicating the potential of quantified SPECT in the follow-up of patients compared to visual assessment of planar images. This image was adapted from Zhao, et al 71 and reprinted under the terms of the Creative Commons CC BY license. DPD = 3,3-diphosphono-1,2-pyrophosphate, ATTR = transthyretin amyloid, SPECT = single-photon emission tomography, SUV = standardised uptake value, TBR = target-to-background ratio.