Data on analysis of coronary atherosclerosis on computed tomography and 18F-sodium fluoride positron emission tomography

This article contains the data showing illustrative examples of plaque classification on coronary computed tomography angiography (CCTA) and measurement of 18F-sodium fluoride (18F-NaF) uptake in coronary atherosclerotic lesions on positron emission tomography (PET). We divided the lesions into one of three plaque types on CCTA (calcified plaque, non-calcified plaque, partially calcified plaque). Focal 18F-NaF uptake of each lesion was quantified using maximum tissue-to-background ratio. This article also provides a representative case with a non-calcified coronary plaque detected on CCTA and identified on 18F-NaF PET/non-contrast computed tomography based on a location of a vessel branch as a landmark. These complement the data reported by Kitagawa et al. (2017) [1].


Specifications
The data explain how to assess 18 F-sodium fluoride ( 18 F-NaF) uptake in coronary atherosclerotic lesions on positron emission tomography (PET).
The data provide a representative case with a non-calcified coronary plaque detected on CCTA and identified on 18 F-NaF PET/non-contrast computed tomography based on a location of a vessel branch as a landmark.

Data
The data presented include the illustrative examples of plaque classification on CCTA ( Fig. 1) and measurement of 18 F-NaF uptake in coronary atherosclerotic lesions on PET (Fig. 2), and images of a case with a non-calcified coronary plaque detected on CCTA and identified on 18 F-NaF PET/noncontrast computed tomography (CT) (Fig. 3).
These complement the data reported by Kitagawa

Study participants
We prospectively recruited 32 patients with known or suspected coronary artery disease (CAD) who underwent both cardiac CT and 18 F-NaF PET/CT between June 2014 and August 2016. To be   3. A 75-year-old male had a NCP in the proximal portion of the left anterior descending artery on CCTA (arrowhead). Its location on 18 F-NaF PET/non-contrast CT (arrows) was determined using a vessel branch as a landmark (asterisks). The fused PET/CT image showed minimal 18 F-NaF uptake corresponding to the NCP (TBR max ¼ 0.88).
included in the 18 F-NaF PET/CT study, the patient had to have at least one coronary atherosclerotic lesion detected on CCTA in segments 42-mm in diameter according to the Society of Cardiovascular Computed Tomography's 18-segment model [2]. Our hospital's ethics committee approved the study protocol, and written informed consent was obtained from all patients.

Cardiac CT scan and image analysis
Cardiac CT scan was performed using a 320-slice CT scanner (Aquilion One; Toshiba Medical Systems, Tokyo, Japan). The data set for CCTA was acquired using the HeartNAVI s system (collimation 320 Â 0.5 mm; tube current 350-580 mA; tube voltage 120 kV; Toshiba Medical Systems) with retrospective electrocardiography gating. All reconstructed CT image data were transferred to an offline workstation (Advantage Workstation Ver. 4.2, GE Healthcare, Waukesha, WI, USA) for post-processing and image analysis.
On CCTA, we divided coronary atherosclerotic lesions into one of three plaque types (Fig. 1): calcified plaque (CP), containing only a structure on the vessel wall with a CT density above that of the contrast-enhanced coronary lumen or with a CT density of 4130 Hounsfield units (HU); noncalcified plaque (NCP), containing only a low-density mass 41 mm 2 in size, located within the vessel wall and clearly distinguishable from the contrast-enhanced coronary lumen and the surrounding pericardial tissue; partially calcified plaque (PCP), containing both CP and NCP components.

18F-NaF PET/CT protocol and image analysis
Combined PET/CT imaging of coronary arteries and superior vena cava was performed using a hybrid scanner (Discovery ST Elite-Performance, GE Healthcare) within 1 month after cardiac CT imaging. The patients were administered a target dose of 370 MBq 18 F-NaF intravenously and subsequently rested in a quiet environment for 60 min. Initially, a non-enhanced CT scan was performed for attenuation correction of the PET images, and then an electrocardiogram-gated emission PET scan of the thorax was performed with a 25-min acquisition using the three-dimensional mode. Immediately after the PET scan, an electrocardiogram-gated CT scan for fusion with PET images was performed with the same axial coverage at 120 kV, 250 mA, a speed of 27.0 mm/rotation, and a slice thickness 1.25 mm. The PET component of the combined imaging system allows simultaneous acquisition of 47 transaxial PET images with an interslice spacing of 3.27 mm in the one bed position. The PET data were reconstructed with an ordered-subset expectation maximization iterative reconstruction algorithm called as VUE Point Plus (21 subsets and two iterations).
The PET data were reconstructed in 8 multiple phases of the cardiac cycle, with the diastolic phase (62.5-75%) used for analysis with an offline workstation (Advantage Workstation Ver. 4.4, GE Healthcare). For 18 F-NaF uptake for coronary atherosclerotic lesions, a region of interest (ROI) was drawn around each lesion on 3.27 mm axial slices just beyond the discernible adventitial border. The maximum SUV (SUV max ) (decay-corrected tissue concentration of the tracer divided by the injected dose per body weight) was measured and divided by an averaged mean SUV in the blood pool, derived from five circular ROIs positioned in the center of the superior vena cava (Fig. 2). This provided a maximum tissue-to-background ratio (TBR max ), which was reported as a measure of 18 F-NaF uptake for each coronary atherosclerotic lesion.

Representative case with a non-calcified coronary plaque
Unlike CP and PCP, NCP detected on CCTA cannot be identified by locations of vessel calcium on non-contrast CT image. Thus, the identification of NCP on 18 F-NaF PET/non-contrast CT was based on locations of vessel branches as landmarks. Fig. 3 shows a case with NCP detected on CCTA and analyzed on 18 F-NaF PET/non-contrast CT.