CTSS and Patent ductus arteriosus: Several promising molecular imaging probes for detection of PanIN lesions have been described, including Claudin-4 and cathepsin-activatable near-infrared probes and a single-photon emission CT (SPECT) probe, based on Plectin-1, which detected primary pancreatic tumours and metastatic foci in orthotopic mouse models of PDA.35–37 The 13C-MRSI experiment described here, however, has several potential advantages.