[11C]PK11195 PET-MRI in mitochondrial disease

A case-control PET-MRI study from the University of Cambridge that imaged the 18 kDa translocator protein (TSPO), an outer mitochondrial membrane protein, with the radioligand [11C]PK11195 in people with genetically confirmed mitochondrial disease. The aim was to see whether TSPO binding can serve as a noninvasive brain biomarker of mitochondrial pathology, rather than only as a marker of neuroinflammation. The images are not public: the paper states that raw data are available from the corresponding author on request. A Dryad record (mirrored on Zenodo) holds only supplementary figures and per-patient statistical map overlays.

Composition

Fifteen patients from a specialist mitochondrial disease clinic at Addenbrooke's Hospital consented; one scan was cancelled, leaving 14. Thirteen were symptomatic and one was an asymptomatic carrier from the family of another patient. Mutations covered both the mitochondrial genome (for example MT-TL1 m.3243A>G, MT-ND6, MT-ND4, MT-ATP6) and nuclear genes (POLG, SPG7, TYMP), with syndromes such as MELAS, MIDD, MNGIE, Leber hereditary optic neuropathy and ataxia. The 33 healthy controls, matched for age and sex, came from a depression study (25) and a Parkinson disease study (8) that used the same protocol on the same scanner.

Acquisition

All participants had one session on a GE Signa PET-MR at 3 T. [11C]PK11195 was injected as a bolus and list-mode PET was recorded for 75 minutes, then reconstructed with time-of-flight OSEM at 2.0 x 2.0 x 2.8 mm voxels. A 1 mm isotropic T1-weighted volume acquired during PET was used for registration and region definition, and T1- and T2-weighted images were read clinically. Binding potential was computed with a simplified reference tissue model after partial volume correction.

Annotations

No image annotations are described. Patients carry clinical labels: mutation, syndrome, modified Rankin Scale and Scale for the Assessment and Rating of Ataxia scores, and radiology findings.

Known limitations

The patient group is small and genetically heterogeneous. Controls were drawn from two other studies; the depression controls share their ethics approval with the BIODEP study. Access depends on the authors, and no terms of use are published.