As shown in Fig. 36.1, a very low-dose CT (120 kV, 10 mA) is performed first, for attenuation correction mapping. Then, ⁸²Rb is administered intravenously in a slow bolus over 30 s with the patient at rest. PET acquisition is started simultaneously in list mode for 6–8 min while the ECG gating signal is recorded. After the generator recovery period (10 min), pharmacological stress is started with adenosine (0.84 mg/kg for 6 min) infusion using a dual-channel infusion port (adenosine + ⁸²Rb) under 12-channel ECG monitoring. ⁸²Rb is injected intravenously 2 min after the beginning of adenosine infusion and stress images are acquired again in list mode with ECG gating signals for 6–8 min. A final, very low-dose CT (120 kV, 10 mA) for attenuation correction mapping may be performed, but in most cases the initial rest CT can be used for attenuation correction in modern systems able to realign PET and CT images if significant movements occurred between the two datasets.

PET images are generally reconstructed using ordered subset expectation maximization algorithms (OSEM, 2 iterations, 24 subsets). From the list mode, two datasets are extracted: (1) a series starting 2 min after injection and synchronized with the ECG (8 bins) and (2) a dynamic series (22 frames: 12 × 8, 5 × 12, 1 × 30 s, 1 × 1 and 2× 2 min).

For the analysis, semiquantitative image interpretation is performed using a 17-, 20- or 25-segment model. The summed stress score (SSS) and summed resting score (SRS) can be determined, together with the summed difference score (SDS = SSS − SRS). Both the left ventricular ejection fraction (LVEF) at rest and during stress can also be derived. Finally, flow quantification measurements based on a one-tissue compartment model can be used to estimate the absolute values of myocardial blood flow at rest and during stress as well as the myocardial flow reserve.

Compared to MP imaging by SPECT, ⁸²Rb cardiac PET/CT provides several advantages: (a) shorter acquisition times, (b) better spatial resolution, (c) built-in attenuation correction, (d) lower radiation exposure, and (e) absolute quantitation of MBF, as well as the myocardial flow reserve.

As there are as yet no guidelines for the clinical use of ⁸²Rb MP imaging PET/CT in the pediatric population, potentially useful indications could be as follows: hypertrophic and dilated cardiomyopathies, myocarditis, Kawasaki’s disease, and congenital abnormalities, including single ventricle, Fallot’s tetralogy, anomalous left coronary artery, unique coronary artery, and transposition of the great vessels [5]. Moreover, particularly relevant to the use of MBF quantitation are research topics such as the development of early endothelial dysfunction in early stages of type 1 diabetes in older children and adolescents [6].